-50

-50

-50

-50

-20

-50

-20

-20

-50

Kotzebue

Sound

C h u k c h i

S e a

Ledyard

Bay

Bering Strait

Kolyuchin

Bay

Wrangel Island

Herald Island

Diomede

Islands

C H U K C H I

A U T O N O M O U S

O K R U G

S e w a r d

U

NITED

STATES

C h u k o t s k

P e n i n s u l a

L i s b u r n e

P e n i n s u l a

(Interna

tio

n

al Date

Lin

e)

RUSSIA

Inchoun R.

Mechigmensk

Bay

Arakamchechen

Ild

Amgue m a

R.

Kotzebue

Kivalina

Diomede

Brevig

Mission

Point

Hope

Point

Lay

W

Shishmaref

Noatak

Provideniya

176°0'0"E 180°0'0" 176°0'0"W 172°0'0"W 168°0'0"W 164°0'0

DRAFT August 2009

397 Washington Street

Duxbury, Massachusetts 02332

Phone: (781) 934-0571

www.battelle.org

OCS Study BOEMRE 2010­032

CONTINUATION OF THE ARCTIC NEARSHORE IMPACT MONITORING 

IN THE DEVELOPMENT AREA (cANIMIDA): SYNTHESIS, 1999 - 2007 

Final Report 

December 2010 

Prepared for: 

Bureau of Ocean Energy Management, Regulation, and Enforcement 

Alaska OCS Region 

Anchorage, Alaska 

Prepared by: 

Jerry M. Neff, Principal Investigator 

Neff & Associates LLC 

20 Templewood Drive 

Duxbury, Massachusetts 02332 

Based on: 

cANIMIDA Task 1 – PI: G.S. Durell, Battelle, Duxbury, MA 

cANIMIDA Task 2 – PI: J.S. Brown, Exponent, Maynard, MA 

cANIMIDA Task 3 & 4 – PI: J.H. Trefry, Florida Institute of Technology, Melbourne, FL 

cANIMIDA Task 5 – PI: J.M. Neff, Neff & Associates LLC, Duxbury, MA 

cANIMIDA Task 6 – PI: K.H. Dunton, University of Texas, Port Aransas, TX 

cANIMIDA Task 7 – PI: M. Galginaitis, Applied Social Research, Anchorage, AK 

(e-mail of corresponding author: neffjm@comcast.net) 

This study was funded by the United States Department of the Interior, Bureau of Ocean Energy 

Management, Regulation, and Enforcement, Alaska Outer Continental Shelf Region, Anchorage, Alaska, 

under Contract No. M03PC00014 to Battelle Memorial Institute, Duxbury, MA, as part of the BOEMRE 

Alaska Environmental Studies Program. 

The opinions, findings, conclusions, or recommendations expressed in this report are those of the authors 

and do not necessarily reflect the views of the U.S. Department of the Interior, nor does the mention of 

trade names or commercial products constitute endorsement or recommendation for use by the Federal 

Government.
This page intentionally left blank
I 

EXECUTIVE SUMMARY 

The cANIMIDA Project extended the ANIMIDA field program to the summers of 2004, 2005, 

2006, and 2007. An explicit goal of the cANIMIDA Project is to examine temporal and spatial 

changes in chemical and biological characteristics of the oil and gas exploration and 

development area of the Alaskan Beaufort Sea and to determine if any observed changes are 

related to the Northstar development and production operations. This review summarizes and 

integrates the results of the ANIMIDA Project (1999 - 2003) and the cANIMIDA Project (2004 - 

2007). 

The ANIMIDA and cANIMIDA Projects are divided into several interrelated monitoring tasks: 

 Sources of sediments and partitioning of metals and hydrocarbons in the Beaufort Sea; 

 Spatial distribution and concentrations of metals and hydrocarbons in sediments on the 

Beaufort Sea continental shelf, with emphasis on the Northstar and Liberty prospect 

areas; 

 Spatial distribution and concentrations of metals and hydrocarbons in tissues of marine 

invertebrates and fish in the Beaufort Sea, with emphasis on the Northstar and Liberty 

prospect areas; 

 Ecology of the Boulder Patch ecosystem adjacent to the Liberty prospect; and 

 Assessment of fall subsistence Bowhead whaling near Cross Island in the development 

area. 

Sources and Partitioning of Sediments, Metals, and Hydrocarbons in the Beaufort Sea 

About 90% of the annual transport of total suspended solids (TSS) from the Sagavanirktok, 

Kuparuk and Colville River occurs during the spring floods. More than 85% of the data points 

for Ba, Cu, Cr, Ni, and Pb in suspended sediments from the three rivers during 2004 and 2006 

were within predicted ratios to Al for Beaufort Sea sediments. This overall continuity shows 

strong support for river particles as a key source for metals in coastal sediments as well as 

showing that anthropogenic inputs or diagenetic processes are not important in controlling 

concentrations of these metals in Beaufort Sea. 

A trend of maximum concentrations of dissolved trace metals in rivers during peak flow in 

spring, first observed during the ANIMIDA Project, was again observed in some cases in the 

2004 and 2006 data. This trend is natural and is influenced by the discharge of soil interstitial 

water and shallow surface water that is diluted by snow melt and flushed from surrounding soils 

into the rivers. In contrast concentrations of dissolved major elements such as Ca, or even Ba, 

varied by <10% over the May-June period in the rivers. 

A simple distribution coefficient (Kd) was used to describe metal partitioning between particulate 

and dissolved phases. For example, the Kd values calculated for Ba in the Sagavanirktok, 

Kuparuk and Colville Rivers were statistically equal, despite differences in absolute values, 

suggesting that partitioning of Ba between dissolved and particulate phases is a quasiequilibrium controlled process between free Ba2+ and suspended particles. Reasonably good 

agreement in Kd values among rivers and seasons also was found for Cd, Cu, Cr, Pb and other 
II 

metals. The Kd relationship can be used to help explain and predict concentrations of dissolved 

metals in area rivers. 

During the spring floods, water from the Sagavanirktok River (SR) was traced beneath the ice, 

relatively undiluted, to a distance of ~6 to 8 km offshore and ~8 to 10 km alongshore in ~3 days. 

The SR plume was ~1.0 to 1.5 m thick with the majority of the river water (>60%) in the top 1 m 

over an area of ~315 km2

. This information can be used to help predict potential spill trajectories 

under ice as well as transport pathways for freshwater, suspended sediments and dissolved 

chemicals in the coastal Beaufort Sea. 

No significant differences in concentrations of TSS were found due to oil and gas operations 

near Northstar Island relative the overall cANIMIDA study area. Concentrations of dissolved 

trace metals were lower than reported values for surface seawater worldwide and well below the 

EPA water quality criteria for chronic impacts in marine waters. No significant difference in 

concentrations of dissolved trace metals were observed near Northstar Island relative to the 

overall cANIMIDA study area during the 2004, 2005 and 2006 study period. 

Concentrations of particulate metals during the open-water season varied as a function of the 

dissolved and particulate organic matter concentrations and the clay concentration and 

composition of suspended sediments, as shown by variations in concentrations of Al and Fe and 

associated shifts in concentrations of trace metals. Concentrations of some metals were 

influenced by uptake by biota (e.g., Cd) and possibly by anthropogenic inputs (e.g., Pb) to metal 

distributions. Only concentrations of particulate Cd during 2004 (plankton) and particulate Pb 

during 2006 (possibly anthropogenic) were higher in the Northstar area than in the overall 

cANIMIDA study area. 

River sediments and peat from river banks and coastal soils contained significant concentrations 

of saturated and polycyclic aromatic hydrocarbons (SHC and PAH). The compositions of the 

SHC and PAH assemblages in the sediments, soils, and peat were consistent with mixed 

petrogenic, pyrogenic, and biogenic sources. The PAH compositions in river sediments and the 

offshore water column and sediments throughout the development area were similar, indicating 

that much of the hydrocarbons in offshore sediments came from terrestrial sources, probably 

eroding peat and organic rich shales and kerogens. 

With respect to potential contaminants, the overall conclusion is that concentrations in suspended 

sediments, as well as dissolved and particulate metals and hydrocarbons in the development area, 

are primarily from terrestrial sources and are nearly always at background levels. 

Metals and Hydrocarbons in Beaufort Sea Sediments 

Monitoring in ANIMIDA and cANIMIDA has shown that there were no detectable associations 

between Northstar development activities and metals and hydrocarbons in sediments and marine 

animals. That is, any observed changes in the monitored environmental conditions were well 

within the natural spatial and temporal variability of the study area. 

Sediment grain size distributions were highly variable on small spatial scales throughout the 

development area, and from year to year. Most areas were erosional rather than depositional; 

highest sediment deposition rates were in the range of 0.04 to 0.3 cm/year. In most of the area, 
III 

sediments were continually deposited from spring river flows and then eroded and transported 

and redistributed by storms in the open-water season. 

Concentrations of 11 metals were similar in surface sediments in the Northstar, Liberty, and 

BSMP areas in 2000 through 2006. None of the metals was consistently present at a higher range 

of concentrations in sediments from the Northstar production facility than in sediments from the 

Liberty prospect or the historic BSMP stations. 

Total polycyclic aromatic hydrocarbon (TPAH), total saturated hydrocarbon (TSHC), and total 

steranes and triterpanes (StTr) concentrations in surface sediments collected throughout the 

development area between 1999 and 2006 indicated that hydrocarbon concentrations increased 

significantly in post-1999 sediments in the Northstar area. However, the composition of the 

different hydrocarbon fractions was similar from year to year, indicating that the higher levels in 

sediments in 2000, after construction of the Northstar facility, were natural and not from 

construction activities. Sediments near Northstar were coarser in 1999 than in 2000, indicating 

that fine grained sediments, containing much of the hydrocarbons, were eroded from sediments 

in the area by storm currents in 1999. 

Metals and Hydrocarbons in Tissues of Marine Animals from the Development Area 

The ANIMIDA/cANIMIDA Project has shown that oil development activities in the Alaskan 

Beaufort Sea are not contributing ecologically important amounts of petroleum hydrocarbons 

and metals to the near-shore marine food web of the of the area. Mean total PAH concentrations 

in fish, deployed mussels, amphipods, isopods, mysids, and clams collected from all stations in 

2004, 2005, and 2006, as well as in fish collected in 2001 and amphipods, clams, and deployed 

mussels collected in 2000 and 2002 in the ANIMIDA Project, were similar to or lower than 

concentrations in the same or similar species from clean coastal waters elsewhere in the world. 

The PAH profiles in tissues of fish and invertebrates from the Beaufort Sea is consistent with a 

mixed petrogenic/pyrogenic source; petrogenic PAH probably are derived from aerial deposition, 

oil and gas operations in the vicinity, erosion of coastal and riverine peat deposits, and runoff 

from land. TPAH concentrations were not higher in tissues of marine animals from the vicinity 

of the Northstar development than in the same species from other locations. The concentrations 

of individual and total PAH in tissues of Beaufort Sea marine animals are well below 

concentrations that would represent a health risk to marine animals and the animals, including 

man, that might consume them. 

Concentrations of 18 metals in tissues of several species of fish, amphipods, isopods, clams, and 

deployed mussels collected in the Northstar development and the Liberty prospect areas and in 

other reference areas were similar in 2004, 2005, and 2006. A few metals concentrations were 

slightly higher in marine animals from Northstar than in the same species from the other 

sampling sites; however, there were no consistent metal, year, or species patterns. Metals 

concentrations were in the range reported for the same or similar species from other locations 

throughout the world, and are below concentrations that would pose a health risk to the marine 

animals or their consumers, including man. There is no evidence that metals from the 

development and production activities at Northstar are entering the Beaufort Sea food web. 
IV 

Regression analysis of concentrations of several metals, TPAH, and TSHC in sediments and 

tissues of benthic amphipods and clams residing in the same sediments, collected between 1999 

and 2006, revealed that there was no relationship between concentrations of metals and 

hydrocarbons in sediments and tissues of amphipods and clams. In most cases, concentrations 

were higher in the sediments than in tissues of the benthic invertebrates. These results indicate 

that the metals and hydrocarbons in sediments of the development area have a very low 

bioavailability. 

Monitoring the Boulder Patch Ecosystem 

The Arctic Kelp, Laminaria solidungula, effectively integrates dynamic ecosystem 

characteristics, such as water transparency in the Stefansson Sound Boulder Patch. These 

ecosystem characteristics may vary due to changing arctic climate and oil and gas development 

along the coast of Northern Alaska. These plants represent excellent indicators of interannual 

changes in nearshore ecosystems and provide an effective way of monitoring such changes. 

Data collected during ANIMIDA/cANIMIDA strongly suggest that both the spatial and 

interannual variations in water transparency are correlated with TSS. In general, the majority of 

the Boulder Patch, including areas with dense kelp populations (> 25% rock cover), was found 

predominantly in clear offshore waters where light attenuation measurements were consistently 

less than 1.0 m-1. Our data show that years characterized by frequent storm activity are likely to 

have significant impacts on annual kelp growth and production. Local climatic change that 

results in more frequent storm events are thus likely to have a significant and detrimental impact 

on nearshore kelp bed community production, and could lead to large scale losses of these plants 

and their associated diverse epilithic and epiphytic fauna. 

Offshore oil and gas operations also could affect the Boulder Patch community if they cause 

increases in TSS concentrations in the water column during the summer open water season. 

There is no indication that this has happened during development of the Northstar facility. 

Concentrations of metals and hydrocarbons are similar in benthic invertebrates collected in the 

Boulder Patch and elsewhere in the development area. 

Monitoring of Subsistence Bowhead Whaling off Cross Island 

The objective of this long-term ongoing study was to determine if offshore oil and gas 

development was affecting the annual (fall) Cross Island subsistence bowhead whale hunt. 

During ANIMIDA/cANIMIDA, Northstar went from construction/development to production. 

Cross Island whalers noted few if any direct effects of Northstar on their whaling activities, other 

than that the whalers themselves avoided scouting for whales near Northstar. The lack of effects 

was attributed primarily to Northstar being west of Cross Island, while the whales were coming 

from the east and so did not encounter any potential disturbance from Northstar until they had 

passed Cross Island and the Nuiqsut whalers. 

The most important factors affecting the success of the whale hunt included stormy weather, ice 

drift into nearshore waters, and unexplained differences from year to year in the time of arrival, 

numbers, and distance from shore of bowhead whales. 
i 

Table of Contents 

EXECUTIVE SUMMARY ............................................................................................................. I

TABLE OF CONTENTS ................................................................................................................. i

LIST OF TABLES ......................................................................................................................... iii

LIST OF FIGURES .........................................................................................................................x

1 0BINTRODUCTION ....................................................................................................................1

1.1 6BProject Background ........................................................................................................1

1.1.1 26BMonitoring Environmental Impacts of Offshore Oil and Gas Exploration 

and Development in the Alaskan Beaufort Sea ............................................... 1

1.1.2 27BThe Beaufort Sea Monitoring Program (BSMP), 1984-1989 ......................... 1

1.1.3 ANIMIDA Phase 1 (1999, 2000), ANIMIDA Phase 2 (2000 - 2002) ............ 2

1.1.4 cANIMIDA (2004-2006) ................................................................................ 4

1.1.5 30BOther Studies Associated with ANIMIDA/cANIMIDA ................................. 6

1.2 7BThe Alaskan Beaufort Sea .............................................................................................6

1.2.1 31BGeographic Setting .......................................................................................... 6

1.2.2 32BPhysical Oceanography ................................................................................... 7

1.3 8BHistory of Oil Exploration and Development in the Alaskan Beaufort Sea ..................8

1.3.1 3BExploratory Drilling, 1981 - 2002 ................................................................... 8

1.3.2 34BDevelopment of Beaufort Sea Oil Resources ................................................ 11

1.4 9BEnvironmental Disturbances Associated With Oil Exploration and Development in 

the Arctic ......................................................................................................................13

1.4.1 35BSeismic Exploration ...................................................................................... 13

1.4.2 36BOffshore Infrastructure Construction ............................................................ 13

1.4.3 37BDrilling Waste Discharges ............................................................................. 15

1.4.4 38BProduction Waste Discharges ........................................................................ 15

1.4.5 39BBlowouts and Oil Spills ................................................................................. 15

1.4.6 40BAir Emissions ................................................................................................ 17

1.4.7 41BWaste Disposal Near Northstar Production Facility ..................................... 17

2 1BMETHODS .............................................................................................................................19

2.1 10BStudy Designs and Field Methods ...............................................................................19

2.1.1 42BSources and Partitioning of Metals and Hydrocarbons in the Beaufort Sea . 19

2.1.2 43BHydrocarbon and Metal Characterization of Sediments in the ANIMIDA 

Study Area ..................................................................................................... 21

2.1.3 4BIntegrated Biomonitoring and Bioaccumulation of Contaminants in Biota 

of the cANIMIDA Study Area ...................................................................... 25

2.1.4 45BLong-Term Monitoring of the Kelp Community in the Stefansson Sound 

Boulder Patch: Detection of Change Related to Oil and Gas Development . 26

2.1.5 46BContinuation of Annual Assessment of Subsistence Bowhead Whaling 

Near Cross Island as part of the cANIMIDA Project .................................... 28

2.2 1BAnalytical Methods ......................................................................................................28
ii 

2.2.1 47BWater Chemistry ............................................................................................ 28

2.2.2 48BAnalysis of Metals in Water, Sediments, and Tissues .................................. 29

2.2.3 49BSediment Grain Size and Total Organic Carbon (TOC) ............................... 31

2.2.4 50BAnalysis of Saturated Hydrocarbons (SHC), Polycyclic Aromatic 

Hydrocarbons (PAH), and Sterane/Triterpane Petroleum Biomarkers 

(StTr) ............................................................................................................. 31

2.2.5 51BAnalysis of CYP1A Activity and Bile Fluorescent Aromatic Compounds 

(FAC) in Fish ................................................................................................. 34

3 2BRESULTS ...............................................................................................................................35

3.1 12BSources of Suspended Sediments, Metals, and Hydrocarbons in the Coastal 

Beaufort Sea .................................................................................................................35

3.1.1 52BTransport of Water, Sediments, and Chemicals from North Slope Rivers 

during the Spring Melt .................................................................................. 35

3.1.2 53BPartitioning of Metals between Dissolved and Particulate Phases in River 

Water and Beaufort Sea Water ...................................................................... 42

3.1.3 54BDispersion of River Water, Suspended Sediments, and Chemicals Under 

the Ice in the Beaufort Sea ............................................................................ 44

3.1.4 5BThe Distribution of Suspended Sediments and Chemicals during the OpenWater Period .................................................................................................. 66

3.1.5 56BHydrocarbons in River Sediments, Peat, Northstar Oil and Nearshore 

Seawater ........................................................................................................ 74

3.1.6 57BBiogeochemistry of Arsenic and Mercury in the Coastal Beaufort Sea ........ 82

3.2 13BCharacterization of Metals and Hydrocarbons in Sediments in the 

ANIMIDA/cANIMIDA Study Area ............................................................................93

3.2.1 58BSediment Grain Size and Concentrations of Total Organic Carbon (TOC), 

and Metals ..................................................................................................... 93

3.3 14BCharacterization of Metals and Hydrocarbons in Tissues of Marine Animals in the 

ANIMIDA/cANIMIDA Study Area ..........................................................................128

3.3.1 59BMetals in Tissues of Marine Animals .......................................................... 128

3.3.2 60BHydrocarbons in Tissues of Marine Animals .............................................. 147

3.4 15BConceptual Model of Bioaccumulation and Trophic Transfer of Chemicals in the 

Beaufort Sea Food Web .............................................................................................160

3.4.1 61BContaminant Sources in the Beaufort Sea ................................................... 160

3.4.2 62BBioaccumulation and Trophic Transfer of Metals and Hydrocarbons in the 

Beaufort Sea Food Web .............................................................................. 162

3.4.3 63BThe Beaufort Sea Food Web ....................................................................... 163

3.5 16BEcology of the Kelp Community in the Stefansson Sound Boulder Patch ................172

3.5.1 64BStudy Design. .............................................................................................. 172

3.5.2 65BLight Attenuation ........................................................................................ 172

3.5.3 Total Suspended Solids (TSS) ..................................................................... 175

3.5.4 67BChlorophyll a Concentrations ...................................................................... 175

3.5.5 68BNutrient Concentrations .............................................................................. 176

3.5.6 69BPhysicochemical parameters ....................................................................... 177

3.5.7 70BContinuous Light Measurements ................................................................. 178

3.5.8 71BKelp Measurements ..................................................................................... 179

3.6 17Monitoring the Boulder Patch: Biodiversity Assessments ........................................182
iii 

3.6.1 72BIntroduction ................................................................................................. 182

3.6.2 73BMacroalgal Communities ............................................................................ 183

3.6.3 74BEpibenthic and Epilithic Invertebrate Communities ................................... 186

3.6.4 75BBiodiversity of the Benthic Community of the Boulder Patch ................... 190

3.6.5 76BDiscussion ................................................................................................... 192

3.6.6 7BComparison with Pre-ANIMIDA Data ....................................................... 196

3.7 18BMonitoring Subsistence Bowhead Whaling near Cross Island, 2001-2007 ..............196

3.7.1 78BThe Bowhead Whale Balaena mysticetus ................................................... 196

3.7.2 79BObjectives .................................................................................................... 197

3.7.3 80BContemporary Subsistence Whaling in Alaska ........................................... 197

3.7.4 81BThe Historic Context of Cross Island Whaling ........................................... 201

3.7.5 82BTrends in Nuiqsut Bowhead Whale Harvest ............................................... 208

3.7.6 83BMethods ....................................................................................................... 211

3.7.7 84BResults ......................................................................................................... 213

4 3BINTEGRATION OF cANIMIDA PROJECT ......................................................................253

4.1 19BObjectives of ANIMIDA/cANIMIDA .......................................................................253

4.2 20BOffshore Oil and Gas Operations in the Beaufort Sea that Could Cause LongTerm Environmental Disturbance. .............................................................................253

4.3 21BSources of Sediments, Metals, and Hydrocarbons in the Beaufort Sea .....................256

4.3.1 85BSediments .................................................................................................... 256

4.3.2 86BMetals .......................................................................................................... 257

4.3.3 87BHydrocarbons .............................................................................................. 258

4.4 2BMetals and Hydrocarbons in Beaufort Sea Water, Sediments, and Marine 

Animals ......................................................................................................................259

4.4.1 8BMetals .......................................................................................................... 259

4.4.2 89BHydrocarbons .............................................................................................. 263

4.5 23BAre Chemicals from Offshore Oil Operations Entering the Beaufort Sea Food 

Web? ..........................................................................................................................266

4.6 24BIs There Evidence of Physical, Chemical, or Biological Changes Caused by 

Construction and Production at Northstar? ................................................................267

4.7 25BPossible Effects of Offshore Oil Development on the Boulder Patch Ecosystem 

and Subsistence Whaling Near Cross Island .............................................................270

5 4BRECOMMENDATIONS .....................................................................................................273

6 5BREFERENCES .....................................................................................................................275 

APPENDIX A ............................................................................................................................. A-1

List of Tables 

Table 1-1. Chronological order of exploratory wells drilled to date or planned on 

State/Federal lease tracts in the U.S. Beaufort Sea. Several wells drilled on State leases 

are not included. Data from MMS, Alaska OCS Region, Anchorage, AK. Spud dates 

for the new wells are tentative because of ongoing litigation. (From Neff, 2010). ............. 9
iv 

Table 1-2. Major activities and associated potential environmental disturbance during 

exploration and development/production of an offshore oil and gas field in the Arctic. 

From Neff et al. (1987). ...................................................................................................... 14

Table 1-3. Estimated volumes of water based drilling mud and cuttings discharged to the 

Alaskan Beaufort Sea from exploratory wells for which information is available from 

Exploration Plans. Volumes are m3

 = 1000 liters or 264 gallons. From Neff (2010). ...... 16

Table 2-1. Station numbers, sorted by area, where sediment and invertebrate tissue 

samples were collected for chemical analysis in ANIMIDA (1999-2002) and 

cANIMIDA (2004-2006). ................................................................................................... 22

Table 2-2. Stations, sorted by area, where fish samples were collected for chemical 

analysis and biomarker assays in ANIMIDA (1999-2002) and cANIMIDA (2004-

2006). Total number of fish samples (8 species sampled) collected at each station and 

year is included. From Spies et al. (2003) and Neff et al. (2009). ...................................... 24

Table 2-3. Summary of instrumental methods and method detection limits (MDL) for 

analysis of metals in water, suspended sediments, sediments, and soft tissues of marine 

animals. Concentrations are μg metal/g dry sediment or mg/L (parts per million). From 

Brown et al. (2009), Neff et al. (2009), and Trefry et al. (2009). ....................................... 30

Table 2-4. Target polycyclic aromatic hydrocarbons (PAH) analyzed in sediments and soft 

tissues of marine animals collected in the ANIMIDA and cANIMIDA program from 

the Beaufort Sea. The C prefix for alkyl PAH indicates the number of alkyl carbons. 

Each alkyl-PAH isomer group is the total of all quantified isomers. Reporting codes are 

used in graphic presentation of PAH data. The MDL for individual PAH or alkyl-PAH 

isomer groups ranged from 1.2 to 4.7 ng/g dry wt.............................................................. 32

Table 2-5. Target saturated hydrocarbons (SHC), including the n-C9 through n-C40 normal 

alkanes, pristane, phytane and selected isoprenoids, analyzed in sediments and soft 

tissues of marine animals in the ANIMIDA and cANIMIDA Programs. The MDL for 

individual saturated hydrocarbons ranged from 40 to 190 ng/g dry wt. ............................. 33

Table 2-6. Target sterane and triterpane (StTr) petroleum biomarkers analyzed in 

sediments and soft tissues of marine animals collected in the ANIMIDA and 

cANIMIDA program from the Beaufort Sea. Reporting codes are used in graphic 

presentation of PAH data. The MDL for individual StTr ranged from 0.01 to 4.7 ng/g 

dry wt. ................................................................................................................................. 33

Table 3-1. Mean, maximum and minimum concentrations of total suspended solids (TSS) 

in the Kuparuk, Sagavanirktok and Colville Rivers during May-June of the years listed. 

From Trefry et al. (2009). ................................................................................................... 37

Table 3-2. Mean and range of concentrations of metals and total particulate organic carbon 

(POC) in suspended sediments collected in the Kuparuk and Sagavanirktok Rivers in 

the spring (May-June) of 2001-2, 2004, and 2006 and in the Colville River in the spring 

of 2001 and 2006. Concentrations are % or μg/g (parts per million) on a dry-weight 

basis. From Trefry et al. (2009). ......................................................................................... 39

Table 3-3. Mean and range of concentrations of dissolved (passing a 0.45 μm filter) metals 

in water collected in the Kuparuk and Sagavanirktok Rivers in the spring (May-June) of 

2001-2, 2004, and 2006 and in the Colville River in the spring of 2001 and 2006. 

Concentrations of dissolved organic carbon (DOC) in river water samples collected in 

June 2001 are included (ANIMIDA task 7: Trefry et al., 2004). Concentrations are μg/L 

(parts per billion) or mg/L (parts per million). From Trefry et al. (2009). ......................... 42
v 

Table 3-4. Mean and standard deviation distribution coefficients (Kd) for metals in spring 

flood water from the Sagavanirktok, Kuparuk, and Colville Rivers. Kd is the ratio of the 

concentration of particulate metal in water (μg metal/g particles) to the concentration of 

the dissolved metal in water (μg metal/g water). From Trefry et al. (2009). ..................... 43

Table 3-5. Concentrations of particulate metals, total suspended solids, and particulate 

organic carbon in Sagavanirktok River water in the spring and summer of 2004, 2005, 

and 2006. From Trefry et al. (2009). .................................................................................. 66

Table 3-6. Concentrations of particulate metals, total suspended solids, and particulate 

organic carbon in Kuparuk River water in the spring and summer of 2004, 2005, and 

2006. From Trefry et al. (2009). ......................................................................................... 67

Table 3-7. Concentrations of dissolved metals in the Sagavanirktok River in the spring and 

summer of 2004, 2005, and 2006. From Trefry et al. (2009). ............................................ 68

Table 3-8. Concentrations of dissolved metals (μg/L) in the Kuparuk River in the spring 

and summer of 2004, 2005, and 2006. From Trefry et al. (2009). ..................................... 68

Table 3-9. Summary data for total suspended solids (TSS) for all stations in the ANIMIDA 

and cANIMIDA study area during the open-water period and for a subset of stations in 

the area of Northstar Island. From Trefry et al. (2009). ..................................................... 70

Table 3-10. Mean concentrations of particulate metals in water samples collected from the 

coastal Beaufort Sea and near Northstar Island (NS) during the open-water season. 

From Trefry et al. (2009). ................................................................................................... 71

Table 3-11. Mean concentrations of dissolved metals and salinity in seawater water collected 

from the coastal Beaufort Sea and near Northstar Island during the open-water season in 2000 

through 2006. All dissolved metal concentrations are μg/L (parts per billion). From Trefry et al. 

(2009). .................................................................................................................................. 73

Table 3-12. Concentrations of TPAH, TSHC, TSrTr, TOC, and silt + clay (mud) in river 

sediments collected in 1985/86 (Boehm et al., 1987) and 1999-2002. From Brown et al. 

(2005). ................................................................................................................................. 75

Table 3-13. Concentrations of TPAH, TSHC, TSrTr, TOC, and silt + clay (mud) in river or 

coastal peat collected in 1985/86 (Boehm et al., 1987), 2000/02 (Brown et al., 2005), 

and 2006 (Brown et al., 2010). ........................................................................................... 77

Table 3-14. Ranges of concentrations of TPAH, 2-3-ring PAH, and ≥ 4-ring PAH in the 

dissolved and particulate fractions of water samples collected as part of ANIMIDA 

Task 7 (2000 to 2002). Concentrations are ng/L (parts per trillion). From Trefry et al. 

(2004a). ............................................................................................................................... 81

Table 3-15. Concentrations of As in surface seawater (dissolved), phytoplankton, 

zooplankton, amphipods (Anonyx sp.), clams (Astarte sp.) and fish collected from the 

coastal Beaufort Sea during the summer of 2005. From Semmler (2006) and Trefry et 

al. (2009). ............................................................................................................................ 86

Table 3-16. Concentrations of total dissolved Hg (TDHg) and dissolved CH3Hg+ in 

selected rivers, estuaries and seawater. Beaufort Sea data are highlighted. From Trefry 

et al. (2009). ........................................................................................................................ 87

Table 3-17. Concentrations of mercury and methylmercury in surface seawater (dissolved), 

mixed phytoplankton, mixed zooplankton, amphipods (Anonyx sp.), clams (Astarte sp.), 

and fish (average for Arctic char, Arctic cisco, Arctic flounder, fourhorn sculpin, and 

humpback broad whitefish from the coastal Beaufort Sea. From Semmler (2006) as 

presented by Neff (2010). ................................................................................................... 91
vi 

Table 3-18. Concentrations of total mercury and methyl mercury in muscle and liver of 

marine mammals collected off Barrow, Alaska. Concentrations are ng/g dry wt, 

converted from wet weight by multiplying by 5. From Dehn et al. (2005, 2006a,b). ........ 93

Table 3-19. Mean and range of concentrations of Al, Fe, TOC, and % silt + clay (mud), in 

sediments from the Northstar, Liberty, and BSMP areas, 2000 - 2006. Al and Fe 

concentrations in sediments are useful for normalization of other metals concentrations 

to the sediment clay fraction. All concentrations are % dry wt. (Data from Brown et al., 

2005, 2009). ........................................................................................................................ 94

Table 3-20. Mean and range of concentrations of As, Ba, Cd, Cr, and Cu, all metals of 

concern during offshore oil and gas development, in sediments from the Northstar, 

Liberty, and BSMP areas, 2000 - 2006. Metals concentrations are mg/kg dry wt (parts 

per million). Data from Brown et al. (2005, 2010). .......................................................... 100

Table 3-21. Mean and range of concentrations of Hg, Pb, and Zn, metals of concern 

during offshore oil and gas development, in sediments from the Northstar, Liberty, and 

BSMP areas, 2000 - 2006. Metals concentrations are mg/kg dry wt (parts per million). 

Data from Brown et al., (2005, 2010). .............................................................................. 102

Table 3-22. Concentrations of arsenic, barium, cadmium, chromium, and copper in 

sediments collected throughout the Alaskan Beaufort Sea between 1984 and 2008 and 

in water based drilling muds (WBM) used in the Beaufort Sea for exploratory wells 

between 1979 and 1982. Concentration ranges are mg/kg dry wt (ppm). From Neff 

(2010). ............................................................................................................................... 107

Table 3-23. Concentrations of mercury, nickel, lead, vanadium, and zinc in sediments 

collected throughout the Alaskan Beaufort Sea between 1984 and 2008 and in WBM 

used in the Beaufort Sea for exploratory wells between 1979 and 1982. Concentration 

ranges are mg/kg dry wt (ppm). From Neff (2010). ......................................................... 108

Table 3-24. Mean and Range of concentrations of total PAH, total SHC, total StTr, TOC, 

and Silt+clay in sediments collected in the Northstar, Liberty, and BSMP areas between 

2000 and 2006 in the ANIMIDA and cANIMIDA Programs. Hydrocarbon 

concentrations are ng/g dry wt (parts per billion) and TOC and silt+clay (mud) are % 

dry wt. Data from Brown et al. (2005, 2009). ................................................................... 110

Table 3-25. Concentration ranges of several metals in fish, mussels, amphipods, and clams 

collected in the Beaufort Sea between 2000 and 2006 as part of the ANIMIDA and 

cANIMIDA Programs, compared to the National Status and Trends median 

concentration ranges for mussels or oysters collected in US coastal waters between 

1986 and 2003 (From O’Connor and Lauenstein, 2006). Concentrations are g/g dry wt 

(ppm). Tissue metals data from Brown et al. (2005) and Neff et al. (2009). .................... 129

Table 3-26. Concentrations of several metals and total polycyclic aromatic hydrocarbons 

(TPAH) in whole or muscle tissues of marine bivalve mollusks, crustaceans, and fish 

from unpolluted marine environments throughout the world. Concentrations are g/g 

dry wt. From Neff (2002).................................................................................................. 130

Table 3-27. Concentrations of 13 metals in whole samples of seven species of fish 

collected from the Beaufort Sea study area during the summer of 2004. n = number of 

replicates. Concentrations are g/g dry wt. Metals concentrations that were 

significantly different in a fish species at different sampling locations are highlighted. . 130
vii 

Table 3-28. Concentrations of 18 metals in amphipods (Anonyx nugax) collected from 

three locations in the Beaufort Sea in 2004. n= number of samples. Concentrations are 

g/g dry wt (ppm). ............................................................................................................ 133

Table 3-29. Statistical comparison of metals concentrations in amphipods (Anonyx sp) 

from BSMP, Liberty, and Northstar in 2004, 2005, and 2006. Only metals for which 

statistically significant differences were detected are included. Differences were 

considered statistically significant for p-values  0.05 (Sokol and Rohlf, 1994) and are 

highlighted. ....................................................................................................................... 134

Table 3-30. Means, standard deviations (SD), relative standard deviations [RSD = 

(mean/SD) x 100], maximums and minimums for metals in 54 samples of amphipods 

(Anonyx) from the ANIMIDA and cANIMIDA study areas for combined data from 

1999-2001, 2003 and 2004-2006. ..................................................................................... 137

Table 3-31. Concentrations of 18 metals in indigenous clams (Astarte montagui and 

Cyrtodaria kurriana) collected from two locations in the Beaufort Sea in 2005. n= 

number of samples. Concentrations are g/g dry wt (ppm). ............................................ 138

Table 3-32. Statistical comparison of metals concentrations in clams (Astarte montagui

and Cyrtodaria kurriana) from Liberty in 2004, 2005, and 2006 and the BSMP stations 

in 2004 and 2005. Only metals for which statistically significant differences were 

detected are included. Differences were considered statistically significant for p-values 

 0.05 (Sokol and Rohlf, 1994) and are highlighted. From Neff et al. (2009). ................ 139

Table 3-33. Concentrations of mercury (Hg) in soft tissues of clams (Astarte montagui and 

Cyrtodaria kurriana) from Liberty and BSMP stations in 2004, 2005, and 2006. 

Concentrations are μg/g dry wt. (parts per million). Data from Neff et al. (2009). ......... 139

Table 3-34. Means, standard deviations (SD), relative standard deviations [RSD = 

(mean/SD) x 100], maximums and minimums for metals in 22 samples of clams 

(Astarte montagui and Cyrtodaria kurriana) from the ANIMIDA and cANIMIDA 

study areas for combined data from 1999-2001, 2003 and 2004-2006. ........................... 141

Table 3-35. Concentrations of 18 metals in Mussels (Mytilus trossulus) following 

deployment in five regions of the Beaufort Sea, compared to the time zero reference 

animals in 2006. n= number of samples. Concentrations are μg/g dry wt. From Neff et 

al. (2009). .......................................................................................................................... 143

Table 3-36. Statistical comparison of metals concentrations in mussels (Mytilus trossulus) 

that were deployed at BSMP, Liberty, and Northstar in 2004, 2005, and 2006. Only 

metals for which statistically significant differences were detected are included. 

Differences were considered statistically significant for p-values  0.05 (Sokol and 

Rohlf, 1994) and are highlighted. From Neff et al. (2009). .............................................. 145

Table 3-37. Mean (± Sd) concentrations of 12 metals in tissues of reference mussels from 

Port Chatham, AK, and mussels from Port Chatham that had been deployed for 2 to 3 

weeks near the Northstar Development in 2002 (ANIMIDA Project), 2004, 2005, and 

2006 (cANIMIDA Program). n= number of samples. Concentrations are μg/g dry wt. 

From Neff et al. (2009). .................................................................................................... 146

Table 3-38. Mean Concentrations of total polycyclic aromatic hydrocarbons, 

dibenzothiophenes, and dibenzofuran (TPAH), total saturated hydrocarbons (TSHC), 

pristane, and steranes/triterpanes (StTr) in tissues of indigenous fish, clams, amphipods, 

isopods, and mysids collected at several locations in the Alaskan Beaufort Sea in 2004 

through 2006. From Neff et al. (2009). ............................................................................. 148
viii 

Table 3-39. Immunohistochemical staining for CYP1A of hepatocytes of fish collected in 

2004 at three Liberty, Northstar, and Tigvariak Island (reference site) and in 2005 at 

Liberty and Northstar. Scaled score range is 0 – 15. n = number of samples. From Neff 

et al. (2009). ...................................................................................................................... 150

Table 3-40. Concentrations of total PAH, total SHC, and total St/Tr in amphipods (Anonyx 

nugax) sampled at 23 sites in 5 monitoring areas in 2006. n = number of samples. 

Concentrations are ng/g dry wt. From Neff et al. (2009). ................................................. 155

Table 3-41. Mean, SD, and range of concentrations of TPAH, TSHC, and StTr in soft 

tissues of amphipods (Anonyx nugax) and clams (Astarte montagui and Cyrtodaria 

kurriana) collected from the Beaufort Sea in 2000 and 2002 (ANIMIDA Task 2) and 

2004, 2005, and 2006 (cANIMIDA Task 5). Concentrations are ng/g dry wt (data for 

2000 and 2002 were converted from wet wt. by multiplying by 5, based on ~89% 

moisture). From Brown et al. (2005) and Neff et al. (2009). ............................................ 157

Table 3-42. Mean Concentrations of total polycyclic aromatic hydrocarbons (TPAH), total 

saturated hydrocarbons (TSHC), pristane, and steranes/triterpanes (StTr) in tissues of 

reference and deployed mussels and of TPAH in blank and deployed SPMDs used to 

monitor bioavailability of hydrocarbon concentrations in the water column of the 

Alaskan Beaufort Sea in 2004 through 2006. From Neff et al. (2009). ............................ 158

Table 3-43. Anadromous and marine fish collected for Task 5 of the cANIMIDA program 

from coastal waters of the Beaufort Sea and their food preferences. Data from 

Thorsteinson and Wilson (2006) and Craig et al. (1984). ................................................. 166

Table 3-44. Diet composition (% of stomach contents) in arctic cod, bowhead whales, 

beluga whales, and ringed seals in the Alaskan Beaufort Sea. From Frost and Lowry 

(1984) and Lowry and Sheffield (2002). .......................................................................... 168

Table 3-45 . Diet composition in black kittiwakes, red phalaropes, Sabine’s gulls, and arctic 

terns feeding in nearshore and offshore waters of the Alaskan Beaufort Sea. From Frost 

and Lowry (1984). ............................................................................................................ 168

Table 3-46. Diet composition in long-tailed ducks, common and king eiders, thick billed 

murres, black guillemots, and glaucous gulls feeding in nearshore and offshore waters 

of the Alaskan Beaufort Sea. From Frost and Lowry (1984). .......................................... 169

Table 3-47. Range of concentrations of selected metals in tissues and organs of bowhead 

whales (Balaena mysticetus) collected by subsistence hunters near Barrow, Alaska. 

Concentrations are mg/kg wet wt (ppm: can be converted to approximate dry wt 

concentration by multiplying by five). From O’Hara et al. (2006). ................................. 171

Table 3-48. TaConcentrations the primary nutrients, ammonium, phosphate, silicate, and 

nitrate + nitrite at two depths in the water column at 30 sites in Stefansson Sound, 

measured on three occasions annually in July and August 2004 - 2006. Values are mean 

± SE in μM. From Dunton et al. (2009). ........................................................................... 177

Table 3-49. Average temperature, salinity, dissolved oxygen, and pH at two depths in the 

water column at 30 sites in Stefansson Sound, measured on three occasions annually in 

July and August 2004 - 2006. Values are means ± SE. From Dunton et al. (2009). ........ 178

Table 3-50. Species and distributions of major taxa of macroalgae in the Boulder Patch in 

2005 and 2006. From Dunton (2009). .............................................................................. 184

Table 3-51. Shannon-Wiener diversity index, Simpson dominance index, and Pielou's 

evenness index for epilithic (living on hard substrates) communities (invertebrates and 

algae) in the Boulder Patch in 2005 and 2006. From Dunton et al. (2009). ..................... 190
ix 

Table 3-52. Documented harvest and struck & lost bowhead whales near Cross Island 

between 1973 and 2007. Years with no documented landed or struck& lost whales are 

not included. From Galginaitis et al. (2009). .................................................................... 203

Table 3-53. Selected measures of Cross Island subsistence bowhead whaling, 2001 

through 2007. From Galginaitis et al. (2009). .................................................................. 214

Table 3-54. Timing and duration of Cross Island subsistence whaling seasons, 2001 

through 2007. From Galginaitis et al. (2009). .................................................................. 217

Table 3-55. Selected measures related to bowhead whale strikes by Cross Island whalers, 

2001 through 2007. From Galginaitis et al. (2009). ......................................................... 219

Table 3-56, Measures related to weather and whale distribution affecting the Cross Island 

subsistence whale hunt, 2001 through 2007. From Galginaitis et al. (2009). ................... 220

Table 3-57. Percent of scouting trips by Cross Island whale boats that had GPS track 

documentation, 2001 through 2007. From Galginaitis et al. (2009). ................................ 223

Table 3-58. Information on the number of whaling crews and boats physically present on 

Cross Island during the 2001 through 2007 whaling seasons, as well as the average total 

population of Cross Island and the average boat crew size during that period. From 

Galginaitis et al. (2009). .................................................................................................... 245

Table 3-59. Measures of Subsistence Whaling Effort by Cross Island Whalers between 

2001 and 2007. From Galginaitis et al. (2009). ................................................................ 247

Table 4-1. Ranges of metal concentrations in water based drilling muds (WBM) used and 

discharged offshore in the Beaufort Sea to drill five exploratory wells between 1973 

and 1983. The exploratory wells were Reindeer Island, Sag Delta 8, Challenge Island, 

Mukluk, and Tern Island. Concentrations are μg/g dry wt. From Neff (2010). Metals 

concentrations in suspended particles in three Arctic Rivers and in Beaufort Sea 

sediments (Tables 3-2 and 3-20) are included for comparison. ........................................ 255

Table 4-2. Rate of discharge of water and total solids from the three largest North Slope 

rivers and from coastal erosion into the development area of the central Alaskan 

Beaufort Sea. Peak flow and sediment discharge, representing 30 to 90% of the total 

annual discharge, occurs during 3 to 12 days in late May and early June each year. Data 

from Rember and Trefry (2004), Trefry et al. (2004), and Alkire and Trefry (2006). ..... 256

Table 4-3. Relationship between wind speed and total suspended solids (TSS) 

concentrations in surface waters of the Beaufort Sea development area during the open 

water speed. Under-ice TSS concentration range is included for comparison. From 

Trefry et al., 2004). ........................................................................................................... 268

Table 4-4. Estimated masses of suspended sediment (TSS), particulate metals and 

particulate organic carbon (POC) carried by the Sagavanirktok, Kuparuk, and Colville 

Rivers to the coastal Beaufort Sea. Masses are metric tons/year. Estimates for the 

Sagavanirktok and Kuparuk Rivers are based on 2001 data collected by Trefry et al. 

(2004) and for the Colville River are from Arnborg et al. (1967). From Trefry et al. 

(2004). ............................................................................................................................... 268
x 

List of Figures 

Figure 1-1. Map of the Alaskan North Slope and the Beaufort Sea showing locations of wells 

drilled. Offshore wells are on State and joint State/Federal lease tracts. Modified from 

National Research Council (2003). ......................................................................................7

Figure 1-2. Map of the Alaskan Beaufort Sea showing locations of exploratory wells drilled 

between 1982 and 2002 on State/Federal lease tracts. The location of Cross Island, 

the site of the annual Nuiqsut bowhead whale hunt also is shown. ...................................10

Figure 2-1. Map showing locations of sampling stations for the cANIMIDA Program in 

relation to locations of exploratory well sites and production facilities. The location 

of Cross Island where the subsistence whaling study was performed (cANIMIDA 

Task 7) also is shown. ........................................................................................................19

Figure 2-2. Sampling sites in Stefannsson Sound with inset map of Alaska showing study 

area during May-June 2004. Causeways connecting the Seawater Treatment Plant 

(STP), Pt. McIntyre, and Endicott Island to shore are shown by the solid lines. Station 

numbers in ovals identify locations where ice cores also were collected. Arrows 

show approximate direction of primary river outflow. From Trefry et al. (2009). ............20

Figure 2-3. Locations of the BSMP, Northstar, and Liberty stations sampled in the 

cANIMIDA Program in relation to exploratory drilling sites and production facilities. ...21

Figure 2-4. Map of the cANIMIDA 2004 - 2006 project study area showing the location 

of the 30 synoptic collection sites used in summers 2004, 2005 and 2006. The thin 

lines outline the areas containing boulders. SDI: Satellite Drilling Island. .......................27

Figure 3-1. Hydrographs during the spring floods in 2001, 2002, 2004 and 2006 for the 

Kuparuk and Sagavanirktok rivers. Data from U.S.G.S. can be accessed at 

Uhttp://waterdata.usgs.gov/ak/nwisU. .................................................................................36

Figure 3-2. Concentrations of calcium (Ca) versus aluminum (Al) for suspended sediments 

from the Sagavanirktok (circles), Kuparuk (diamonds), and Colville (triangles) 

Rivers during 2001, 2002, 2004 and 2006. Markers show means and lines show 

standard deviations. From Trefry et al. (2009). .................................................................38

Figure 3-3. Concentrations of iron (Fe) versus aluminum (Al) for suspended sediments 

from the Sagavanirktok (circles), Kuparuk (diamonds) and Colville (triangles) 

Rivers during May-June 2004 and 2006. Solid line is from a linear regression for 

sediment data from the ANIMIDA study area and dashed lines show 99% prediction 

interval for sediment data. From Trefry et al. (2009). .......................................................40

Figure 3-4. Concentration of barium (Ba) versus aluminum (Al) for suspended sediments 

from the Sagavanirktok (circles), Kuparuk (diamonds), and Colville (triangles) 

Rivers during May-June 2004 and 2006. Solid lines are from linear regressions for 

sediment data from the ANIMIDA study area and dashed lines show 99% prediction 

intervals for sediment data. From Trefry et al. (2009). ......................................................40

Figure 3-5. Vertical profiles for salinity and temperature for stations K1, K3 on May 23, 2004 

and station K4 on May 29, 2004, all located offshore of the mouth of the Kuparuk 

River (See Figure 2-2 for station locations. From Trefry et al. (2009). .............................45

Figure 3-6. Under-ice vertical profiles of temperature, salinity, and turbidity taken along 

the SE transect off the Sagavanirktok River, starting near the bottom-fast ice zone 

and extending offshore beyond the barrier islands just south of the offshore shear 

zone, 1 June 2004. From Trefry et al. (2009). ..................................................................46
xi 

Figure 3-7. Quasi-synoptic view of the percent Sagavanirktok River (SR) water (top) and 

Kuparuk River (KR) water (bottom) at 1.0 m for May 27-31. Water mass fractions 

were rounded to the nearest 10%. From Trefry et al. (2009). ............................................48

Figure 3-8. Qualitative flow pathways for Sagavanirktok River (SR) water according to 

lowest negative gradients and the calculated area of influence of the SR plume 

(rectangle). Solid triangles show the locations of the SR and Kuparuk River (KR) 

outflows in gradient calculations. The lengths of arrows show the distance over 

which the SR plume was observed. From Trefry et al. (2009). .........................................51

Figure 3-9. Total suspended solids (TSS) versus salinity (a) full-scale for TSS and 

(b) TSS at 0 to 50 mg/L for the Sagavanirktok River and offshore in Stefansson 

Sound during May-June 2004. Dashed line on (a) shows simple mixing line between 

TSS of average river water (127 mg/L) and seawater (1 mg/L). Solid line on 

(a) and (b) shows simple mixing line between lowest value for TSS in river water 

during peak flow (43 mg/L) and a value of 1 mg/L for seawater. From Trefry et al. 

(2009). ................................................................................................................................53

Figure 3-10. Vertical profiles of turbidity at station SW4 on May 25, May 28 and May 31, 

2004. From Trefry et al. (2009). ........................................................................................54

Figure 3-11. Concentrations of dissolved As versus salinity for water samples collected 

under ice across the mixing zones from the Sagavanirktok and Kuparuk Rivers to the 

coastal Beaufort Sea. Shaded area was drawn to emphasize the range of dissolved As 

concentrations in the polar mixed layer. Line and equation are from a linear 

regression. Dashed lines show 95% prediction interval. From Trefry et al. (2009). .........55

Figure 3-12. Concentrations of particulate Fe (a) and Ba (b) versus particulate Al for 

samples from the Sagavanirktok and Kuparuk Rivers and the coastal Beaufort Sea. 

Solid lines are from a linear regression and dashed lines show 95% prediction intervals 

based on sediment data for the coastal Beaufort Sea. From Trefry et al. (2003, 2004). ....57

Figure 3-13. Concentrations of particulate Cd versus particulate Al for water samples from 

the Sagavanirktok and Kuparuk rivers and the coastal Beaufort Sea. Solid line is 

from a linear regression and dashed lines show 95% prediction intervals based on 

sediment data for the coastal Beaufort Sea from Trefry et al. (2003). From Trefry 

et al. (2009). .......................................................................................................................58

Figure 3-14. Concentrations of dissolved Cd versus salinity for water samples collected 

under ice across the mixing zones from the Sagavanirktok and Kuparuk Rivers to the 

coastal Beaufort Sea. The solid line and equation are from a linear regression 

calculation, r is the correlation coefficient, and the dashed lines show the 95% 

prediction interval. From Trefry et al. (2009). ...................................................................59

Figure 3-15. Concentrations of particulate Cd versus dissolved Cd in water samples collected 

in the Sagavanirktok and Kuparuk Rivers and under ice in the coastal Beaufort Sea. 

From Trefry et al. (2009). ..................................................................................................59

Figure 3-16. Concentrations of particulate Pb versus particulate Al in water samples from 

the Sagavanirktok and Kuparuk Rivers and the coastal Beaufort Sea. From Trefry 

et al. (2009). .......................................................................................................................60

Figure 3-17. Map showing sampling stations for the May-June 2006 under-ice study in the 

coastal Beaufort Sea. From Trefry et al. (2009). ...............................................................61

Figure 3-18: Vertical profiles of temperature, salinity, and turbidity taken at station S2 

over a 10-day period during May-June 2006. The accompanying map depicts the 
xii 

station location along with the location of the onshore-offshore transect for salinity. 

From Trefry et al. (2009). ..................................................................................................61

Figure 3-19. Vertical contour map of salinity along an onshore-offshore transect extending 

from Station S0 near shore to Station S6 beyond the barrier islands, June 2, 2006 

(refer to above map in Figure 3-16 for transect location). From Trefry et al. (2009). .......62

Figure 3-20. Concentrations of dissolved As (a), Cd (b), Ba (c), and Cr (d) versus salinity 

across the freshwater-seawater mixing zone from the Sagavanirktok River to the 

coastal Beaufort Sea. Solid lines and equations are from linear regression 

calculations. Dashed lines show 95% prediction intervals and r is the correlation 

coefficient. From Trefry et al. (2009). ..............................................................................64

Figure 3-21. Concentrations of Fe versus Al for suspended sediments from the Sagavanirktok 

River (a) and Kuparuk River (b) and respective offshore, under-ice plumes in the 

coastal Beaufort Sea. Solid lines and equations are from linear regression analysis 

for the 1999-2002 data for bottom sediments from the coastal Beaufort Sea; dashed 

lines show 99% prediction intervals and r is the correlation coefficient. From 

Trefry et al. (2009). ............................................................................................................64

Figure 3-22. Concentrations of Al versus (a) Pb, (b) Cu, (c) Cr and (d) Zn in suspended 

sediments from the Sagavanirktok and Kuparuk Rivers and their respective offshore, 

under-ice plumes in the coastal Beaufort Sea. Solid lines and equations are from 

linear regression analysis for the 1999-2002 data for bottom sediments from the 

coastal Beaufort Sea; dashed lines show 99% prediction intervals and r is the 

correlation coefficient. From Trefry et al. (2009). .............................................................65

Figure 3-23. Concentrations of particulate (a) Cd and (b) As versus particulate Al in 

suspended sediment samples collected during May-June (Spring) and July-August 

(Summer) 2004. Solid and dashed lines show the linear regression fit and prediction 

interval based on data for bottom sediments. From Trefry et al. (2003, 2009). ................72

Figure 3-24. SHC, PAH, and StTr profiles in river sediments collected in 2002. SHC. PAH, 

and StTr acronyms are defined in Table, 2-4 - 2-6. Data from Brown et al. (2005). ........76

Figure 3-25. SHC, PAH, and StTr profiles in river peat collected in 2006. SHC, PAH, and 

StTr acronyms are defined in Table, 2-4 - 2-6. Data from Brown et al. (2010). ...............78

Figure 3-26. Mean SHC, PAH, and StTr profiles in Northstar crude oil collected in 2004. 

SHC, PAH, and StTr acronyms are defined in Table, 2-4 - 2-6. Data from Brown 

et al. (2010). .......................................................................................................................80

Figure 3-27. Concentrations of dissolved As versus salinity across the freshwater-seawater 

mixing zone from the Sagavanirktok River to the coastal Beaufort Sea during 

summer 2005. The solid line is a conservative mixing line between river water and 

seawater. From Trefry et al. (2009). ..................................................................................83

Figure 3-28. Concentrations of (a) As versus Al and (b) Fe versus Al in total suspended 

solids (TSS) and bottom sediments collected from Stefannsson Sound during the 

summer of 2005. Solid lines are from a linear regression and dashed lines are 95% 

prediction intervals for bottom sediments from the coastal Beaufort Sea collected in 

1999 through 2001 (Trefry et al., 2003; n = 194). From Trefry et al. (2009)....................85

Figure 3-29. Average concentrations of As in phytoplankton, zooplankton, amphipods 

(Anonyx sp.), clams (Astarte sp.) and fish collected from Stefannsson Sound during 

summer 2005. From Trefry et al. (2009). ..........................................................................86
xiii 

Figure 3-30. Vertical profiles of (upper left) dissolved CH3Hg+, (upper right) dissolved As, 

(lower left) dissolved reactive phosphate (DRP), and (lower right) dissolved NO3

-

 in 

seawater at station L01 (Figure 2-3) on August 3, 2005. From Trefry et al. (2009). .......89

Figure 3-31. Concentrations of total Hg and CH3Hg+ in phytoplankton and zooplankton (top) 

and total Hg in phytoplankton, zooplankton, amphipods, clams, and fish (bottom) 

collected from Stefansson Sound during summer 2005. From Trefry et al. (2009). .........92

Figure 3-32. Concentrations of barium versus aluminum (a) and chromium versus aluminum 

(b) in sediments collected in 2004, 2005, and 2006. Metals concentrations plotting 

above the upper 99% prediction interval may be from anthropogenic sources. From 

Brown et al. (2009). .........................................................................................................101

Figure 3-33. Concentrations of Aluminum (Al) versus barium (Ba) in sediment core 

samples collected in 2005 (top) and 2006 (bottom), showing the sediment samples that 

plotted above the upper prediction interval. Most of the anomalous Ba concentrations 

were in cores from Camden Bay in 2005 and Harrison Bay in 2006. From Brown 

et al. (2010). .....................................................................................................................105

Figure 3-34. Vertical profile of the Ba/Al concentration ratio in a sediment core collected in 

2006 at station 7E in Harrison Bay. Exploratory drilling occurred on State leases 

near this site in 1985-6 and the Ba/Al peak probably is from drilling muds 

discharged during exploratory drilling. From Brown et al. (2009). .................................106

Figure 3-35. Regression plot of the concentration of total PAH (μg/kg = ng/g) minus 

perylene versus %silt+clay for all sediment samples collected between 1999 and 

2006 in the Northstar, Liberty and BSMP areas. The R2 and 99% prediction intervals 

are shown. Most ratios fall within the 99% prediction intervals. From Brown 

et al. (2009). .....................................................................................................................111

Figure 3-36. PAH profiles of surface sediments collected at Northstar station N06 in 1999 

(top) and in 2006 (bottom). Construction of the Northstar production facility occurred 

in the winter of 1999-2000. The PAH profiles are similar, but the concentrations 

of all individual PAH except perylene are lower in 2006 than in 1999. From Brown 

et al. (20010). ...................................................................................................................112

Figure 3-37. Scatterplot of % silt+clay versus TPAH minus perylene in surficial sediments 

at Northstar collected in 1999 through 2006. The 95% confidence interval for the 

mean regression and related statistical calculations for Northstar stations by year 

 are included. Station N08 from year 2004 was an outlier and was excluded from 

this graph. From Brown et al. (2010). ..............................................................................116

Figure 3-38. Pyrogenic:petrogenic ratios of Northstar surficial sediment samples collected 

 in 1999 through 2006. From Brown et al. (2010). ..........................................................118

Figure 3-39. Double Ratio Source Plot of C2D/C2P vs. C3D/C3P for surface sediments 

from BSMP, Liberty, Northstar, and Arctic rivers collected between 1999 and 2006 

and North Slope and for Northstar crude oils. From Brown et al. (2010). ......................119

Figure 3-40. Double Ratio Source Plot of S25/S28 vs. T21/T22 steranes and triterpanes in 

BSMP, Liberty, Northstar, and River Sediment Samples collected in 1999 through 

2006. From Brown et al. (2010). ......................................................................................120

Figure 3-41. PAH profiles for the 0-2 cm (top) and 8-10 cm intervals in a sediment core 

collected at Northstar station N26 in 2005. From Brown et al. (2010). ..........................123
xiv 

Figure 3-42. Profiles of TPAH, perylene, TSHC (TPHC), TStTr (Total ST) concentrations, 

pyrogenic/petrogenic PAH ratios, and % silt+clay in a sediment core from BSMP 

station 7A. From Brown et al. (2010). .............................................................................124

Figure 3-43. Vertical profiles of TPAH, perylene, TSHC (TPHC), TStTr (Total ST) 

concentrations, pyrogenic/petrogenic PAH ratios, and % silt+clay in a sediment 

core from BSMP station 7E, where there is evidence of exploratory drilling 

activities in the 1980s. From Brown et al. (2010)............................................................125

Figure 3-44. Double Ratio Source Plot of C2D/C2P vs. C3D/C3P for sediment core 

samples collected in 2001, 2005, and 2006, Northstar crude oil, river sediments, 

and peat. From Brown et al. (2010). ...............................................................................127

Figure 3-45. Double ratio source plot of S25/S28 versus T21/T22 petroleum biomarkers 

for BSMP, Liberty, Northstar sediment core samples. From Brown et al. (2010). .........127

Figure 3-46. Mean ± SD concentrations of 13 metals in whole soft tissues of mixed 

assemblages of fish collected in the Liberty and Northstar areas in 2006. 

Concentrations are μg/g dry wt. From Neff et al. (2009). ...............................................132

Figure 3-47. Concentrations of arsenic (As), barium (Ba), copper (Cu), and cadmium 

(Cd) in amphipods (Anonyx nugax) collected from nearshore waters of the Beaufort 

Sea between 1986 and 2006. Markers show the annual mean concentrations and 

lines show ± 1 standard deviation. Markers with no lines have an SD that is smaller 

than the marker. From Neff et al. (2009). ........................................................................135

Figure 3-48. Concentrations of arsenic chromium (Cr), mercury (Hg), lead (Pb), and Zinc 

(Zn) in amphipods (Anonyx nugax) collected from nearshore waters of the Beaufort 

Sea between 1986 and 2006. Markers show the annual mean concentrations and 

lines show ± 1 standard deviation. Markers with no lines have an SD that is smaller 

than the marker. From Neff et al. (2009). ........................................................................136

Figure 3-49. Concentrations of arsenic (As). barium (Ba), copper (Cu), and cadmium 

(Cd) in clams from the coastal Beaufort Sea in 1986 through 2006. Markers show 

the annual mean concentrations and lines show ± 1 standard deviation. Markers 

with no lines have an SD that is smaller than the marker. From Neff et al. (2009). .......140

Figure 3-50. Concentrations of chromium (Cr), mercury (Hg), lead (Pb), and Zinc (Zn) 

in clams (Astarte montagui) collected from nearshore waters of the Beaufort Sea 

between 1986 and 2006. Markers show the annual mean concentrations and lines 

show ± 1 standard deviation. Markers with no lines have an SD that is smaller 

than the marker. From Neff et al. (2009). ........................................................................140

Figure 3-51. Mean metals concentrations in reference mussels collected at Port Chatham 

in 2004, 2005, and 2006. Note that the y-axis is log scale. From Neff et al. (2009). ......144

Figure 3-52. Profiles of mean concentrations of individual PAH in tissues of fish from 

Northstar and Liberty collected in 2006. From Neff et al. (2009). ..................................149

Figure 3-53. Mean and SD concentrations of fluorescent aromatic compounds (FACs) 

in bile of fish collected in three areas in the Beaufort Sea in 2004 (top) in the 

Northstar and Liberty areas in 2005 (bottom). Concentrations of naphthalene, 

phenanthrene, and benzo(a)pyrene equivalents are ng/μg bile protein (= μg/mg 

protein). ............................................................................................................................151

Figure 3-54. The PAH profile in tissues of amphipods and isopods collected at BSMP, 

Liberty, and Northstar in 2006. From Neff et al. (2009). ................................................153
xv 

Figure 3-55. The PAH profile in tissues of mysids collected at Northstar (top) and clams 

collected at Liberty (bottom) in 2006. From Neff et al. (2009). ......................................154

Figure 3-56. A generalized food web structure showing the sources of organic carbon, 

including peat, in the Alaskan Beaufort Sea coastal ecosystems. The shading of the 

rectangles below each taxon shows the relative contribution and pathway of carbon 

from freshwater algae, terrestrial peat, and marine algae in the food web. Food 

chain structure grades from near-shore, freshwater/estuarine on the left to offshore 

marine on the right. Modified from Schell et al. (1982). .................................................164

Figure 3-57. The importance of zooplankton and arctic cod in the Arctic pelagic food 

web leading to mammalian consumers, including man. Based on Macdonald 

et al. (2005). .....................................................................................................................167

Figure 3-58. Combined mean attenuation coefficient (k) values calculated from 

measurements collected at 2 m and 4 m water depths in summers 2004, 2005 and 

2006. Areas of >10% rock cover are outlined in black. From Dunton et al. (2009). .....173

Figure 3-59. Combined mean total suspended solids (TSS) mg/L from samples collected 

at 2 m and 4 m water depths in 2004, 2005 and 2006. Areas of >10% rock cover 

are outlined in black. From Dunton et al. (2009). ............................................................174

Figure 3-60. Chlorophyll a concentrations (μg L-1) measured in 2004, 2005 and 2006. 

Samples were collected at 4 m water depth. Areas of >10% rock cover are outlined 

in black. From Dunton et al. (2009). ................................................................................176

Figure 3-61. Variation in annual growth in Laminaria solidungula from 1996 to 2006 at s 

ites in the Stefansson Sound Boulder Patch. Measurements are based on blade 

lengths of plants collected between 2001 and 2006 under the ANIMIDA project. 

Values are means. From Dunton et al. (2009). ................................................................180

Figure 3-62. Annual mean linear growth of Laminaria solidungula as a function of the 

number of hours that wind speed exceeded m/s at SDI in July and August, 2001 to 

2006. Wind speed data from Veltcamp and Wilcox, 2007. Sites DS-11 (blue) and 

E-1 (green) are located in the Stefansson Sound Boulder Patch. From Dunton 

et al. (2009). .....................................................................................................................181

Figure 3-63. Stefansson Sound, showing the Boulder Patch area in relation to the Liberty 

prospect and the Endicott and SDI production facilities. From MMS (2007). ................183

Figure 3-64. Map of the cANIMIDA Task 6 study area. The labeled stations are historic 

Boulder Patch stations that have been visited repeatedly since 1984, and resampled 

for biodiversity in 2005 and 2006. During summers 2004, 2005 and 2006, 

long-term light was measured at sites DS-11, E-1, and W-1; kelp blade length data 

were also collected at these sites. .....................................................................................185

Figure 3-65. Absolute contribution of species to total macroalgal biomass (g ww/0.25m2) 

across sites in 2005 and 2006. Note difference in scale in the two years. From 

Dunton et al. (2009). ........................................................................................................187

Figure 3-66. Relative biomass contributions of major invertebrate taxa in a) 2005 and b) 

2006. “Others” includes Anthozoa, Crustacea, Echinodermata and Nemertea. 

From Dunton et al. (2009). ..............................................................................................188

Figure 3-67. Relative abundance contributions of major invertebrate taxa in a) 2005 and 

b) 2006. Encrusting and colonial taxa are excluded. “Others” includes Anthozoa, 

Crustacea, Echinodermata and Nemertea. From Dunton et al. (2009). ...........................189
xvi 

Figure 3-68. Biomass (a) and abundance (b) of invertebrate taxa in sediment cores 

collected in the Boulder Patch in 2005. From Dunton et al. (2009). ...............................191

Figure 3-69. Biomass (a) and abundance (b) of invertebrate taxa in sediment cores 

collected in the Boulder Patch in 2006. From Dunton et al. (2009). ...............................192

Figure 3-70. A map showing the generalized spring (eastward) and fall (westward) bowhead 

whale migration routes and locations of Alaskan subsistence whaling communities. 

The draft map was prepared by the National Science Foundation, the Barrow Arctic 

Science Consortium, and the North Slope Borough. From 

Galginaitis et al. (2009). ...................................................................................................198

Figure 3-71. Estimated population size of the Bering-Chukchi-Beaufort Sea stock of 

bowhead whales between 1978 and the present. From Gakginaitis et al. (2009). ...........199

Figure 3-72. Number of bowhead whales struck in the annual subsistence hunt by year 

and country. Whales landed and struck and lost are indicated. From Galginaitis 

et al. (2009). .....................................................................................................................200

Figure 3-73. Map showing the location of Nuiqsut and Cross Island, the routes taken by 

whalers to move to and from the island and a GPS tracks map for whale hunts 

performed each fall between 2001 and 2007. From Galginaitis et al. (2009). ................201

Figure 3-74. Historic trend in length in feet of bowhead whales landed by Nuiqsut whalers 

from Cross Island between 1982 and 2007. From Galginaitis et al. (2009). ...................210

Figure 3-75. Historic trend in date of bowhead whale landings by whalers from Cross 

Island between 1982 and 2007. From Galginaitis et al. (2009). ......................................210

Figure 3-76. GPS tracks for all bowhead whale scouting trips from Cross Island on 

September 7, 2007. From Galginaitis et al. (2009). .........................................................224

Figure 3-77. Historic bowhead whale strike locations in the Cross Island/Prudhoe Bay 

area between 1987 and 1992. From Long (1996) as presented in Galginaitis 

et al. (2009). .....................................................................................................................225

Figure 3-78. Bowhead whale strike locations near Cross Island between 2001 and 2007. 

From Galginaitis et al. (2009). .........................................................................................227

Figure 3-79. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2001. From Galginaitis et al. (2009). ..............................................................232

Figure 3-80. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2002. From Galginaitis et al. (2009). ..............................................................233

Figure 3-81. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2003. From Galginaitis et al. (2009). ..............................................................235

Figure 3-82. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2004. From Galginaitis et al. (2009). ..............................................................237

Figure 3-83. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2005. From Galginaitis et al. (2009). ..............................................................239

Figure 3-84. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2006. From Galginaitis et al. (2009). ..............................................................241

Figure 3-85. Relationships between weather conditions, bowhead whale scouting trips, and 

strikes in 2007. From Galginaitis et al. (2009). ..............................................................242

Figure 4-1. Regressions of barium and chromium concentrations in sediments and tissues 

of amphipods (A, C) and clams (B, D) collected at several stations in the Northstar, 

Liberty, and BSMP areas of the Beaufort Sea between 1999 and 2006. 

Approximately 40 sediment/amphipod and 25 sediment/clam concentration pairs 
xvii 

were available (Table 2-1). Concentrations in sediments, amphipods, and clams are 

mg/kg dry wt (parts per million). .....................................................................................260

Figure 4-2. Regressions of lead and zinc concentrations in sediments and tissues of 

amphipods (A, C) and clams (B, D) collected at several stations in the Northstar, 

Liberty, and BSMP areas of the Beaufort Sea between 1999 and 2006. 

Approximately 40 sediment/amphipod and 25 sediment/clam concentration pairs 

were available (Table 2-1). Concentrations in sediments, amphipods, and clams are 

mg/kg dry wt (parts per million). .....................................................................................262

Figure 4-3. Regressions of arsenic and mercury concentrations in sediments and tissues of 

amphipods (A, C) and clams (B, D) collected at several stations in the Northstar, 

Liberty, and BSMP areas of the Beaufort Sea between 1999 and 2006. 

Approximately 40 sediment/amphipod and 25 sediment/clam concentration pairs 

were available (Table 2-1). Concentrations in sediments, amphipods, and clams are 

mg/kg dry wt (parts per million). .....................................................................................263

Figure 4-4. Regressions of total PAH (TPAH) and total SHC (TSHC) concentrations in 

sediments and tissues of amphipods (A, C) and clams (B, D) collected at several 

stations in the Northstar, Liberty, and BSMP areas of the Beaufort Sea between 1999 

and 2006. Approximately 40 sediment/amphipod and 25 sediment/clam concentration 

pairs were available (Table 2-1). Concentrations in sediments, amphipods, and clams 

are mg/kg dry wt (parts per million). ...............................................................................265

 
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1 

1 0BINTRODUCTION 

1.1 6BProject Background 

1.1.1 26BMonitoring Environmental Impacts of Offshore Oil and Gas Exploration and 

Development in the Alaskan Beaufort Sea 

The Outer Continental Shelf Lands Act (OCSLA) of 1953 is administered by the US Department 

of the Interior, Minerals Management Service (MMS) (renamed the Bureau of Ocean Energy 

Management, Regulation and Enforcement [BOEMRE]), and covers the territorial seas from the 

outer boundary of state waters to the edge of the exclusive economic zone (200 nautical miles 

[370 km]). The Submerged Lands Act, also enacted in 1953, gave the Federal Government title 

to submerged lands located on a majority of the continental margin. States were given 

jurisdiction over any natural resources within 3 nautical miles (5.55 km) off the coastline (except 

Texas and the west coast of Florida, where jurisdiction extends to 9 nautical miles (16.66 km). 

The OSCLA subsequently defined the outer continental shelf (OCS) as any submerged US land 

outside State jurisdiction. In 1983, the government declared Federal jurisdiction over the US 

Exclusive Economic Zone (EEZ), defined as all waters up to 200 nautical miles (370 km) from 

the U.S. coastline. 

The OCSLA guides and regulates many offshore oil and gas activities from initial leasing of 

Federal offshore lands on the US outer continental shelf to emplacement of offshore 

development and production platforms, pipelines, and floating production, storage, and 

offloading facilities (FPSO), to final decommissioning and removal of platforms (MMS, 1987). 

It includes requirements for monitoring environmental impacts of exploration, development, and 

production activities. 

Amendments of 1978 (92 Stat. 629) established a policy for the management of oil and gas 

development on the Outer Continental Shelf (OCS) and for protection of the marine and coastal 

environments. The amendments authorize the Secretary of the Interior to conduct studies in areas 

of offshore leasing activities to assess potential impacts on the marine and coastal environments 

resulting from oil exploration, development, and production activities. 

BOEMRE Alaska OCS Region is responsible for managing oil and gas development in Federal 

waters of Alaska, including the Beaufort and Chukchi Seas. Shallow State and Federal waters of 

the Beaufort Sea continental shelf were made available for exploratory drilling through a series 

of joint Federal/State lease sales, beginning in 1979. BOEMRE has sponsored three major 

environmental effects monitoring projects in the Beaufort Sea: the Beaufort Sea Monitoring 

Program (BSMP), the Arctic Nearshore Impact Monitoring in the Development Area 

(ANIMIDA) Project, and the Continuation of the Arctic Nearshore Impact Monitoring in the 

Development Area (cANIMIDA) Project. The objective of this report is to summarize and 

integrate the results of the ANIMIDA and cANIMIDA Projects. 

1.1.2 27BThe Beaufort Sea Monitoring Program (BSMP), 1984-1989 

Shallow State and Federal waters of the Beaufort Sea continental shelf were made available for 

exploratory drilling through a series of lease sales, beginning in 1979 with the joint Federal/State 

Beaufort Sea Oil and Gas Lease Sale (Sale BF), followed by Sale 71 in 1982, Sale 87 in 1984, 
2 

and several additional sales. The oil industry showed great interest in lease tracts in the eastern 

and western Alaskan Beaufort Sea. 

In 1983, MMS and the National Oceanic and Atmospheric Administration (NOAA) cosponsored a workshop to develop approaches to assess the potential for environmental 

disturbance from exploratory drilling in the Beaufort Sea. The proceedings of the workshop 

(Dames and Moore, 1984) established a framework for environmental monitoring and for 

implementing the initial phase of the BSMP. 

The BSMP was performed in two phases. The initial three-year project was performed between 

1984 and 1986 and focused mainly on areas offered in Beaufort Sea Lease Sales BN, 71, and 87. 

The objective of Phase 1 of the BSMP was to evaluate the impact of offshore oil and gas 

exploration and production on environmental quality of the Beaufort Sea through examination of 

changes in the concentrations of metals and hydrocarbons in sediments and tissues of marine 

animals. The specific objectives of the initial three-year project were: 

 To detect and quantify changes in the concentrations of trace metals and hydrocarbons in 

Beaufort Sea sediments and sentinel marine animals that might: 

o result from discharges from OCS oil and gas exploration activities; 

o adversely affect or induce adverse effects on humans or those parts of their 

environment by which they judge quality; and 

o influence Federal OCS management decisions. 

 To identify the potential causes of these changes. 

The results of Phase 1 of the BSMP were summarized in a final report (Boehm et al., 1987) and 

publications (Crecelius et al., 1990; Steinhauer and Boehm, 1992). 

Phase 2 of the BSMP was performed in 1989. The sampling and analytical projects were 

modified slightly from those in Phase 1 to address additional needs of MMS. The most important 

changes were: 

 To extend the regional survey to include three stations east of Barter Island; and 

 To add six additional stations around the Endicott development area to help identify 

gradients of chemical parameters in sediments with distance from the facility. 

The results of Phase 2 of the BSMP were summarized in a final report (Boehm et al., 1990). 

1.1.3 ANIMIDA Phase 1 (1999, 2000), ANIMIDA Phase 2 (2000 - 2002) 

In 1998, MMS decided to perform additional monitoring studies in the Beaufort Sea to 

characterize the pre-construction and pre-development marine environment in the Northstar and 

Liberty prospects and to continue to monitor selected environmental parameters over time to 

assess possible long-term effects of these oil development and production activities, the first to 

occur on Federal OCS lease tracts in the Beaufort Sea. MMS intended to use information 

generated in these studies in post-leasing decisions aimed at minimizing and mitigating any 

environmental effects of development activities in the Beaufort Sea. 
3 

The primary objectives of the ANIMIDA Project were to monitor and characterize the marine 

environment of the Northstar and Liberty development areas to evaluate potential and actual 

effects of these major offshore oil developments. The ANIMIDA Project initially was designed 

to carefully monitor environmental disturbance directly related to construction, drilling, and 

production activities at Northstar and Liberty. Priorities were placed on characterizing the preconstruction marine environmental baseline to aid in establishing a scientific basis for postconstruction and production monitoring (Phase 1) and repeated monitoring after initiation of 

production at Northstar at site-specific and regional stations to detect long-term and area-wide 

disturbance of the marine environment in the development area (Phase 2). 

Phase 1 of ANIMIDA was designed and implemented with a focus on the 1999 late-summer, 

open-water period and the 2000 winter, ice covered period. The late summer 1999 sampling 

represented pre-construction baselines at both the Northstar and Liberty areas. The winter 2000 

sampling represented the first construction monitoring period at Northstar and another preconstruction data acquisition opportunity for Liberty. The results of Phase 1 of the ANIMIDA 

Project were summarized in a final report (Boehm et al., 2001). 

Phase 2 of ANIMIDA focused on monitoring during the summers of 2000 and 2002 at the same 

regional BSMP and site-specific Northstar and Liberty stations as were sampled in Phase 1. 

Phase 2 also included support for ongoing studies of the ecology of the Boulder Patch, near the 

Liberty prospect and subsistence bowhead whaling at Cross Island, off Prudhoe Bay. Phase 2 of 

ANIMIDA included seven technical tasks in addition to a project management task (Task 1). The 

seven technical tasks were the following. 

Task 2: Hydrocarbon and Metal Characterization of Sediments, Bivalves, and Amphipods 

in the ANIMIDA Study Area. Task 2 was designed to characterize potential chemical 

contaminants in sediments and marine animal tissues (bivalve mollusks and amphipod 

crustaceans) near ongoing and proposed offshore oil developments and to serve as a continuation 

of the Phase 1 organic and inorganic chemistry project. 

Task 3: Baseline Acoustic Monitoring: Bowhead Whale Migration Corridor. The primary 

objective of Task 3 was to augment the design of BP Exploration Alaska (BPXA), the leaseholder for the Northstar prospect, for acoustic monitoring of bowhead whale migration offshore 

of Northstar by adding one or two seafloor recorder systems further offshore than the BP 

recorders. This task was deferred indefinitely; results of the Phase 1 component of this project 

were summarized by Shepard et al. (2001). 

Task 4: Annual Assessment of Subsistence Bowhead Whaling Near Cross Island. The 

objective of this task was to provide an annual narrative report describing subsistence bowhead 

whaling activities, resources, and harvests on and near Cross Island offshore of Prudhoe Bay. 

Task 5: Sources, Concentrations and Dispersion Pathways for Suspended Sediment in 

Areas of Oil and Gas Development along the Coastal Beaufort Sea. The objectives of this 

task were to determine the amounts of suspended sediments introduced each year to the nearshore Beaufort Sea from rivers, concentrations of suspended sediments at different distances 

from construction- related gravel deposits during open-water and ice-covered seasons, and 

sources of suspended sediments near the Northstar and Liberty development areas. 
4 

Task 6: Monitoring the Boulder Patch. The objective of Task 6 was to monitor the potential 

effects of future Liberty Island and pipeline construction activities on the unique biological 

communities in the Boulder Patch. The focus of the work was to establish the relationship 

between total suspended solids (TSS) concentrations and the amount of light available for 

primary production by the macroalgal community of Stefansson Sound. 

Task 7: Partitioning of Potential Contaminants between Dissolved and Particulate Phases 

in Waters of the Coastal Beaufort Sea. The objectives of this task were to determine the 

concentrations of selected metals and hydrocarbons in dissolved and particulate forms in 

nearshore waters of the Beaufort Sea and partition coefficients and equilibrium kinetics of these 

chemicals in the Beaufort Sea, particularly after sediment resuspension events. 

Task 8: Baseline Characterization of Anthropogenic Contaminants in Biota Associated 

with the Liberty and Northstar Production Facilities in the Nearshore Beaufort Sea. The 

objectives of Task 8 were to detect exposure and effects of anthropogenic chemicals, including 

those that might be released to the environment during development of offshore oil resources, in 

fish, including some of importance in the subsistence fishery, in the nearshore Beaufort Sea. 

Baseline levels of organochlorines and hydrocarbons and exposure biomarkers, cytochrome 

P450 (CYP1A) and bile fluorescent compounds were measured in several species of fish 

collected throughout the development area. 

1.1.4 cANIMIDA (2004-2006) 

The cANIMIDA Project extended the ANIMIDA field project to the summers of 2004, 2005, 

and 2006. cANIMIDA included six technical tasks and a project management task (Task 1). An 

explicit goal of the cANIMIDA Project was to examine temporal and spatial changes and to 

determine if any observed changes in chemical and biological characteristics of the development 

area of the Beaufort Sea are related to the current Northstar development and production 

operations. The objectives of the six technical tasks are as follows. 

Task 2: Hydrocarbon and Metal Characterization of Sediments in the ANIMIDA Study 

Area. 

This task is a continuation of parts of ANIMIDA Task 2. The key questions, which drive Task 2 

of cANIMIDA, are as follows:

 What are the background concentrations of chemicals of concern (i.e., metals and 

hydrocarbons) that are known to be associated with oil exploration, development, and 

production activities, and are the concentrations of these chemicals increasing in area 

sediments as a result of development and production? 

 If concentrations of metals and/or hydrocarbons do increase in the environment as a 

result of development and production activities, do the increased concentrations exceed 

environmental quality guidelines (Effects Range-Lows [ERLs]: Long et al., 1995)? 

 What trends in the background levels of metal and hydrocarbon concentrations in 

sediments that are known to be associated with oil exploration, development, and 

production activities are seen in the historic sediment record, and do the concentrations of 

these chemicals increase as a result of these activities? 
5 

Task 3: Sources, Characteristics and Dispersion Pathways for Suspended Sediment in the 

cANIMIDA Study Area 

and 

Task 4: Partitioning of Potential Contaminants between Dissolved and Particulate Phases 

in the cANIMIDA Study Area. 

These two tasks were closely coordinated and are a continuation of ANIMIDA Tasks 5 and 7. 

The objectives of Tasks 3 and 4 are to:

 Determine the major element, trace metal, and organic carbon content of water and 

suspended sediments carried to the coastal Beaufort Sea by the Sagavanirktok, Kuparuk 

and Colville Rivers. 

 Determine concentrations of dissolved and particulate metals across the freshwaterseawater mixing zone into the Beaufort Sea. 

 Determine pathways for transport of water, chemicals and suspended sediments from 

rivers under ice to the coastal Beaufort Sea during the spring floods. 

 Determine concentrations of suspended sediments, dissolved metals, particulate metals 

and supporting parameters in the coastal Beaufort Sea, including areas near offshore oiland gas-related activities such as Northstar. 

 Determine distribution coefficients (Kd) for metals in the Beaufort Sea and adjacent 

rivers. 

Task 5: Integrated Biomonitoring and Bioaccumulation of Contaminants in Biota of the 

cANIMIDA Study Area. 

Task 5 is a continuation of certain aspects of ANIMIDA Tasks 2 and 8. The objectives of Task 5 

are to:

 Improve and validate the Contractor’s proposed conceptual model of bioaccumulation 

and trophic interaction in cANIMIDA biota. 

 Measure bioaccumulation of metals and hydrocarbons in selected species, including 

indigenous bivalves, benthic amphipods, and fish, and in caged bivalves and SPMDs. 

 Compare bioaccumulation data from the Beaufort Sea to published data for the same or 

similar species outside the cANIMIDA area. 

 Develop a strategy for longer-term upper trophic level contaminant monitoring. 

 Develop a strategy and rationale for future Boulder Patch contaminant monitoring in 

conjunction with cANIMIDA Task 6. 

Task 6: Monitoring the Boulder Patch as Part of the cANIMIDA Project. 

cANIMIDA Task 6 is a continuation of ANIMIDA Task 6. The overarching objective of Task 6 

field studies in the cANIMIDA project is: 
6 

 To use synoptic and long-term measurements of photosynthetically active radiation 

(PAR), light attenuation coefficients, total suspended solids (TSS; mg/L), and indices of 

benthic diversity and kelp biomass to determine the impact of sediment resuspension on 

kelp productivity and biodiversity in the Stefansson Sound Boulder Patch. 

Task 7: Continuation of Annual Assessment of Subsistence Bowhead Whaling Near Cross 

Island as part of the cANIMIDA Project. 

cANIMIDA Task 7 is a continuation of ANIMIDA Task 7. This study has gathered long-term 

monitoring data to help the MMS assess whether OCS oil development activities at Northstar 

and/or Liberty result in changes to bowhead whale subsistence hunting practices, or to hunting 

success at Cross Island. Two research questions addressed in this study are:

 Does Cross Island subsistence whaling display significant variation over time? 

 Can such variation be attributed to offshore oil and gas industrial activities? 

1.1.5 30BOther Studies Associated with ANIMIDA/cANIMIDA 

MMS Alaska OCS Region also sponsored a physical oceanographic project in the ANIMIDA 

area. These oceanographic studies of water currents and water properties were performed from 

1999 and 2007 and were coordinated with but not part of ANIMIDA/cANIMIDA. The results of 

these and related studies of the physical oceanography of the Beaufort Sea have been 

summarized by Potter and Weingartner (2009), Weingartner (2006), Weingartner and Okkonen 

(2001), and Weingartner et al. (2005, 2009). 

1.2 7BThe Alaskan Beaufort Sea 

1.2.1 31BGeographic Setting 

The physical characteristics of the Beaufort Sea, including the development area monitored in 

ANIMIDA/cANIMIDA, have been described in detail in the Environmental Impact Statements 

for the Oil and Gas Lease Sales for Beaufort Sea Planning areas 87, 97, 124, 144, 202, 209 

(MMS, 1984, 1987, 1990, 1996, 2006, and 2008, respectively). 

The Beaufort Sea is the southern part of the Arctic Ocean off the coasts of Alaska and the Yukon 

and Northwest Territories of Canada. The Alaskan Beaufort Sea extends from the Barrow Sea 

Valley off Point Barrow eastward approximately 600 km to the Alaska-Canadian border and 

northward for a distance of 322 km (200 miles) to water depths greater than 100 m at 73°N 

latitude (Figure 1-1). The continental shelf of the Alaskan Beaufort Sea, measured from the 

shoreline to the 200-m isobath, is about 60 to 120 km wide, among the narrowest in the 

circumpolar Arctic (NRC, 2003), with an average water depth of about 37 m (USAEDA, 1999). 

The continental slope in the northern Beaufort Sea extends to a depth of more than 1000 m. The 

major bathymetric features on the inner continental shelf, 1.6 to 32 km from the coast, are barrier 

islands and shoals, the boundaries of which migrate from year to year, due mainly to spring 

freshets from rivers and winter ice scour (Weingartner et al., 2005). 

 
7 

Figure 1-1. Map of the Alaskan North Slope and the Beaufort Sea showing locations of wells 

drilled. Offshore wells are on State and joint State/Federal lease tracts. Modified from 

National Research Council (2003). 

1.2.2 32BPhysical Oceanography 

Three distinct oceanic regimes bound the Alaskan Beaufort Sea and influence water masses and 

current regimes in the Beaufort Sea (Weingartner et al., 2009; Potter and Weingartner, 2009). To 

the west, waters from Pacific Ocean and Bering Sea flow northward through the Bering Strait 

and across the Chukchi shelf. Part of the Barrow Canyon outflow continues eastward as a 

subsurface current (or slope undercurrent) along the Beaufort shelf-break and slope, where it 

forms the upper waters of the Canada Basin. Part of the water rounds Point Barrow and 

continues onto the inner portion of the western Beaufort Shelf. 

The outer shelf and continental slope provide the offshore boundary for the Alaskan Beaufort 

Sea. In the upper ~50 m, the flow is westward and part of the southern limb of the wind-driven 

Beaufort Gyre. This flow can occasionally be reversed by strong winds from the east and/or by 

occasional shelf-break upwelling that advects eastward momentum from the slope undercurrent 

onto the shelf as far inshore as the 50 m isobath (Potter and Weingartner, 2009). 
8 

The Mackenzie shelf joins the Alaskan Beaufort shelf to the east and water currents on the 

eastern Beaufort Sea shelf (Canada) are influenced by year-round discharges from the Mackenzie 

River, the largest river flowing into the Arctic Ocean off North America (Potter and 

Weingartner, 2009). Mackenzie shelf water has been detected throughout much of the Canada 

basin, including the continental slope of the western (Alaskan) Beaufort Sea and Chukchi Sea as 

far west as 160°N latitude. Wind-driven currents also transport Mackenzie shelf waters westward 

onto the inner shelf of the Alaskan Beaufort Sea. The Mackenzie River and several smaller rivers 

introduce large volumes of fresh water, containing suspended sediments, metals, and 

hydrocarbons, into near-shore waters of the Canadian and Alaskan Beaufort Seas affecting 

nearshore water currents. 

There are two distinct water circulation patterns in the Alaskan Beaufort Sea. Water currents on 

the inner shelf in water depths of less than 40 meters are strongly wind driven and undergo 

dramatic seasonal changes due mainly to buildup of land-fast ice. Because the principal wind 

direction is from the northeast in all seasons, particularly during the spring and fall, including 

ice-free season, nearshore flow usually is westward, (Weingartner et al., 2009; Potter and 

Weingartner, 2009). 

Residual water currents on the outer continental shelf (water depths greater than 40 meters) are 

dominated by the Beaufort Gyre, flowing toward the west, and the Beaufort Undercurrent, which 

transports Pacific/Bering water eastward to the Canadian Beaufort Sea (NRC, 2003; Weingartner 

et al., 2005). 

Sea ice can cover the Beaufort Sea shelf year-round; however, the inner shelf (and the entire 

shelf in recent years) is ice-free during summer months from late June to the beginning of 

October (Weingartner et al., 2009). Land-fast ice begins to form in October and extends 20 to 40 

km offshore until mid-June. The OCS may remain ice-free longer, although ice usually covers 

the entire shelf by late November. Ice ridges form as the ice extends offshore. Ice keels extend 

beneath the ridges and can gouge the seafloor if the offshore ice moves inshore during spring 

breakup. 

1.3 8BHistory of Oil Exploration and Development in the Alaskan Beaufort Sea 

1.3.1 3BExploratory Drilling, 1981 - 2002 

Shallow State and Federal waters of the Beaufort Sea continental shelf were made available for 

exploratory drilling through a series of lease sales, beginning with Federal/State Beaufort Sea Oil 

and Gas Lease Sale (Sale BF) in 1979. Thirty-one exploratory wells were drilled over a period of 

23 years (1981 to 2002) in State/Federal lease tracts administered by MMS between Barrow and 

Kaktovik in the Alaskan Beaufort Sea (Wainwright, 2002; NRC, 2003) (Table 1-1, Figure 1-2). 

The Alaska Dept. of Natural Resources (ADNR, 2007) lists 19 oil and gas fields in State and 

Federal waters of Alaska. Some of the wells in these fields are in State lease tracts in coastal 

waters (< 5.55 km from shore) in the Beaufort Sea. 
9 

Table 1-1. Chronological order of exploratory wells drilled to date or planned on State/Federal 

lease tracts in the U.S. Beaufort Sea. Several wells drilled on State leases are not included. 

Data from MMS, Alaska OCS Region, Anchorage, AK. Spud dates for the new wells are 

tentative because of ongoing litigation. (From Neff, 2010). 

Prospect Spud Datea Water Depth (m) Drilling Unit 

Beechey Point 11/1/81 5.5 Gravel Island 

Beechey Point 12/27/81 5.5 Gravel Island 

Tern 5/28/82 6.4 Gravel Island 

Tern 10/16/82 6.4 Gravel Island 

Mukluk 11/1/83 15 Gravel Island 

Cross Island 11/2/83 0.15 - 2.4 Gravel Island 

Seal 2/4/84 12 Gravel Island 

Antares 11/1/84 15 CIDSc 

Antares 1/19/85 15 CIDSc 

Seal 2/22/85 12 Gravel Island 

Hammerhead 8/10/85 31 Explorer II Drillship 

Harvard 9/2/85 15 Gravel Island 

Orion 11/10/85 15 CIDSc

Sandpiper/Harvard 2/8/86 15 Gravel Island 

Mars 3/12/86 7.6 Ice Island 

Corona 7/28/86 35 Explorer II Drillship 

Phoenix 9/23/86 18 SSDC/MATd

Hammerhead 9/27/86 33 Explorer II Drillship 

Tern 2/10/87 6.7 Gravel Island 

Aurora 11/2/87 20 SDC/MATb

Belcher 9/5/88 51 Kulluke

Fireweed 10/19/90 15 SCD/MATb 

Galahad 9/15/91 51 Explorer II Drillship 

Cabot 11/1/91 17 SDCb

Kuvlum 8/22/92 34 Kulluke

Kuvlum 7/28/93 29 Kulluke

Kuvlum 9/7/93 33 Kulluke

Wild Weasel 10/13/93 27 Kulluke

Liberty 2/7/97 6.4 Gravel/Ice Island

Warthog 11/1/97 11 CIDSc

McCovey 12/6/02 11 SDC/MATb 

Proposed Exploratory Wells 

Sivulliq 2011 31 Frontier Discoverer Drillship a

 Spud date is the date drilling was started; b SDC/MAT, steel drilling caisson or steel drilling caisson/drilling mat 

unit; c

 CIDS, concrete island drilling system; d SSDC/MAT, single steel drilling caisson/drilling mat; e Kulluk, an 

ice-reinforced conical drilling unit (CDU). 

 
10 

Figure 1-2. Map of the Alaskan Beaufort Sea showing locations of exploratory wells drilled 

between 1982 and 2002 on State/Federal lease tracts. The location of Cross Island, the 

site of the annual Nuiqsut bowhead whale hunt also is shown. 

Records are incomplete on drilling in State lease tracts in waters of river deltas and coastal 

lagoons and within 5.5 km of the shore or barrier islands. At least 33 exploration, delineation, 

and development wells were drilled in State waters before 1986 (2 wells at Northstar, 6 wells at 

Niakuk, and 25 wells at Endicott) (Boehm et al., 1987). Several exploratory wells were drilled 

from gravel pads on or adjacent to barrier islands in state waters (e.g., Endeavor Island, 

Resolution Island, Challenge Island, Goose Island, and Alaska Island). Three exploratory wells 

were drilled in 2003 from a gravel island at the Oooguruk prospect located about 8 km off 

Harrison Bay in about 1.5 m of water. 

Shell Offshore, Inc. (SOI, 2009) plans to drill an exploratory well in the Beaufort Sea on the 

Sevulliq prospect near the Hammerhead prospect, discovered by Union Oil Co. in 1985-1986 

(Table 1-1). Drilling has been delayed several times, and currently is expected to occur during 

the summer of 2011. The exploratory drill sites are in approximately 30 m of water 24 miles 

north of Flaxman Island off Camden Bay. An ice-reinforced drillship, the Frontier Discoverer, 

will be used for exploratory drilling. 
11 

Exploratory wells located in shallow water (6 to 15 m) close to shore in the Beaufort Sea were 

drilled from man-made islands constructed from gravel and/or ice or from concrete island 

drilling system (CIDS) or steel drilling caisson/drilling mats (SDC/MAT) (Table 1-1). Gravel 

islands constructed for exploratory drilling usually are much smaller than those constructed for 

development/production facilities. Mukluk Island was just over half an acre, compared to five 

acres for the Northstar production facility and six acres for the Oooguruk drilling island. Most of 

these wells were drilled during the winter when ice was present and they were accessible from 

shore via ice roads. Further offshore in deeper (15 to 21 m) water, exploratory wells were drilled 

from specialized bottom-founded drilling units such as concrete island drilling units (CIDS), 

single steel caisson systems (SSDC or SDC/MAT), or the single steel drilling caisson (SSDC), a 

converted tanker that sat on a reinforced steel platform and could be moved, allowing year-round 

drilling (McCracken et al., 2007). McCovey, the most recent exploratory well drilled in the 

Alaskan Beaufort Sea (2002), as well as the Paktoa C-60 exploratory well drilled off the 

Mackenzie River delta in the Canadian Beaufort Sea in 2004 were drilled from the SDC/MAT. 

Wells located in deeper water further offshore were drilled during the open-water season using 

ice-reinforced floating drill rigs such as the 24-sided conical drilling unit, the Kulluk, and the 

drillship Frontier Explorer. 

1.3.2 34BDevelopment of Beaufort Sea Oil Resources 

Eleven of the exploratory wells in the Beaufort Sea were discoveries with a potential for 

development (NRC, 2003). Five of these were significant discoveries: Kuvlum, Hammerhead, 

Sandpiper, Tern Island/Liberty, and Seal Island/Northstar (ADNR, 2009). Seven producing fields 

include offshore production (Badami, Endicott, Milne Point, Niakuk, Northstar, Point McIntyre, 

and Oooguruk). However, all but Endicott, Northstar, Point McIntyre, and Oooguruk are being 

produced through directional wells drilled from onshore facilities. The Endicott, Northstar, Point 

McIntyre, and Oooguruk facilities were constructed on gravel islands. Both Endicott and Point 

McIntyre use causeways to support offshore drilling and production facilities. Northstar, the only 

facility that gathers oil from Federal waters, pumps oil to shore by buried, ice-resistant pipelines 

and uses winter ice roads for re-supply of materials. 

The Liberty prospect will be developed by ultra-extended-reach drilling from and expansion of 

the existing Endicott satellite drilling island (BPXA, 2007). 

1.3.2.1 90BEndicott 

Endicott was the first continuously-producing offshore oil field in the Arctic, including the 

Alaskan Beaufort Sea (BPXA, 2004). Endicott is near the Tern Island prospect discovered and 

delineated in 1982-1987 (Table 1-1). The original discovery well was drilled in the Duck 

Island/Sag Delta prospect leased by Exxon in the 1969 State Lease Sale 23 and Sohio in the 1979 

State/Federal Lease Sale BF. The field was developed by BPXA with deviated wells drilled from 

two man-made gravel islands located in 4 m of water. Production facilities and producing wells 

are located on the 45-acre Main Production Island. Producing wells also are located closer to 

shore on the Satellite Drilling Island (SDI). The production islands are connected to the mainland 

by a 2.5-km long gravel causeway. The causeway has breaches that are crossed by steel bridges 

to allow passage of migratory anadromous fish and to minimize disruption of nearshore currents. 

Oil production began at Endicott in October 1987 and oil is transported to shore by pipeline on 

the causeway. Production began at Sag Delta North in 1989 and at Eider in 1998 through long-
12 

reach deviate wells from Endicott’s main production island. In 2004, there were 70 oil producing 

wells, five gas injection wells, and 28 water injection wells at the Endicott production facility, as 

well as one oil producing well and one water injection well for the Eider satellite production, and 

two oil producing wells and two water injection wells for the Sag Delta North satellite 

production (BPXA, 2004). 

1.3.2.2 91BNorthstar 

Northstar, the only Arctic production facility producing Federal oil, is in State waters, but with 

bottomhole locations partly in Federal waters. Northstar was developed from a five-acre manmade gravel island constructed partly on the remains of the old Seal Island and from additional 

gravel hauled to the island from a gravel mine site near the mouth of the Kuparuk River. The 

island is surrounded by a linked concrete mat armor island slope protection system and the 

working surface of the island is surrounded by sheet piling. Shell Oil Company discovered oil at 

Seal Island in 1983 and drilled four additional appraisal wells there between 1983 and 1986 

(Siok, 1999). BPXA acquired Seal Island in 1995. The Northstar production island is outside the 

barrier islands about 19 km northwest of Prudhoe Bay and 9.7 km offshore in about 12 m of 

water. Island construction began in the winter of 1999-2000. In 2004, Northstar had 15 

producing wells and five gas-injection wells (BPXA, 2004). Northstar is connected to onshore 

oil processing facilities by a double pipeline that was buried 2.1 to 3.4 m below the seafloor to 

avoid damage from ice scour. Continuous oil production began in November 2001. 

Although the Northstar Island is in Alaska State waters, several slant wells were drilled into 

Federal waters. State and Federal leases were allocated 82.16 percent and 17.84 percent, 

respectively, of total unitized production. Total oil production rose from 201,259 m3

 in 2001 to 

3,987,245 m3 in 2004 and then declined to an estimated 446,964 m3 in 2010. Thus, total unitized 

annual production has declined by 88.8% between 2004 and 2010 (MMS Production Stats, July 

2010). 

1.3.2.3 92BOooguruk 

The Oooguruk facility was constructed on an artificial gravel island in State waters. Oil 

production began in June 2008 and is expected to reach 2400 to 3200 m3

/day in 2010. The 

facility consists of three main components – an offshore drill site, an onshore interconnect and 

production support facility, and a system of flowlines, power cables, and communications cables 

connecting the onshore and offshore facilities. The offshore drill site is a six-acre artificial gravel 

island about 9 km from shore with facilities for development drilling and field operations. Forty 

horizontal development wells will be drilled from the island, half of them for production and half 

for water injection. 

1.3.2.4 93BLiberty 

The Liberty Prospect is inside the barrier islands about 10 km offshore in Foggy Island Bay, at a 

water depth of about 7 m. The Liberty Prospect is a short distance south of the Boulder Patch, a 

unique and sensitive marine ecosystem. It is approximately 50 km southeast of the Northstar 

development and about 10 km from the Endicott Causeway, near Tern Island, where Shell Oil 

Co. drilled in 1982 (MMS. 2007). BP Exploration (Alaska), Inc. (BPXA) drilled the discovery 

well in the Liberty Prospect in 1997. The original development plan for Liberty called for 

development drilling from an artificial island, similar to that at Northstar. In August 2005, BPXA 
13 

announced that it will develop the Liberty Prospect by ultra-extended-reach drilling (uERD) 

from an expansion of the existing Endicott SDI, mitigating potential offshore environmental 

impacts to the Boulder Patch, marine mammals, and concerns of the North Slope Inupiat 

communities related to the bowhead whale and subsistence whaling. Six wells are planned, four 

producing wells and two waste injection wells, in the initial phase of development. The wells 

will extend 10.3 to 13.0 km from the drill site and to a vertical depth below the sea floor of about 

3.4 km (BPXA, 2007). The Final Development and Production Plan for Liberty was submitted to 

MMS in April 2007 (BPXA, 2007). 

1.4 9BEnvironmental Disturbances Associated With Oil Exploration and 

Development in the Arctic 

1.4.1 35BSeismic Exploration 

Many operations performed during evaluation, exploration, and development/production of 

offshore oil and gas resources may cause physical disturbance or chemical contamination of the 

marine environment (Table 1-2). Seismic surveys during geophysical evaluation produce loud 

noises that may harm or alter behavior of marine animals, particularly marine mammals 

(pinnipeds and cetaceans) that naturally rely on acoustic navigation and communication. There is 

no evidence that the low-frequency, high-energy sound pulses produced by modern, towed 

acoustic arrays consisting of air guns cause physical harm to marine animals, though they may 

cause avoidance reactions in some marine mammals (OGP, 2004). 

1.4.2 36BOffshore Infrastructure Construction 

Platform, gravel island, and subsea pipeline construction and emplacement during exploration, 

development, and production may cause physical disturbance at the sea floor and may interfere 

with other uses of the local marine environment. Construction sounds associated with winter and 

summer construction, development drilling, and production activities at Northstar were moderate 

in the winter, below levels likely to cause significant disturbance to marine animals and birds. 

The sounds reached background levels within 7.5 km under water, 3 km in the air, and 10 km for 

in-ice vibrations. Background sound levels were reached closer to the island in the summer. 

However, some airborne sounds from the island were heard up to 37 km away (Blackwell and 

Greene, 2006; Greene et al., 2008). 

As discussed above, most exploratory drilling and all development operations in the Beaufort 

Sea were performed from artificial gravel Islands or grounded drilling structures, such as the 

concrete island drilling system (CIDS) and the single steel drilling caisson/drilling mat 

(SDC/MAT) (Table 1-1). These structures cause considerable long-lasting physical disturbance 

to the sea floor, effectively smothering all benthic fauna in the area of the facility footprint. 

 
14 

Table 1-2. Major activities and associated potential environmental disturbance during 

exploration and development/production of an offshore oil and gas field in the Arctic. 

From Neff et al. (1987). 

Activity Potential Disturbance 

Geophysical Evaluation 

Seismic surveys Low-frequency noise effects on marine animals, particularly marine 

mammals 

Exploration 

Drilling structure emplacement Seabed disturbance from gravel island construction or grounded 

drilling structure emplacement, and anchor scour and mud line cellar 

emplacement from floating rigs 

Drilling Discharge of drilling muds and cuttings, and risk of blowout 

Routine drilling structure 

operations 

Discharge of deck drainage, cooling water, and sanitary wastewater 

Drilling structure support 

operations 

Discharges from support vessels and coastal port development 

Development and Production 

Platform installation Disturbance to navigation, and marine animal migration, reef effects 

(fish attraction and biofouling), seabed disturbance from platform 

structure, template, anchor scour, and bottom scour 

Drilling Large volumes of drilling mud and cuttings from multiple wells, 

accumulation of solids on the sea floor, creating a cuttings pile that 

may contain elevated concentrations of metals and hydrocarbons, and 

risk of a blowout or oil spill. 

Pipeline construction Disturbance to the sea floor 

Produced water disposal Treatment and discharge to ocean, transport to shore, or reinjection 

Platform support operations Support vessel traffic, exhaust and wastewater discharges from vessels, 

and coastal port development 

Routine platform operations Discharge of deck drainage, cooling and firefighting water, and treated 

domestic wastewater 

Since 1975, more than 20 gravel islands have been constructed in waters less than 15 m deep on 

State and State/Federal lease tracts in the Alaskan Beaufort Sea for exploratory drilling and 

production. Most of these islands remain in some form, but most have been abandoned by 

removal of all equipment and erosion protection. Natural barrier islands also have been used for 

exploratory drilling activities and for staging areas (USAEDA, 1999). Gravel drilling pads were 

constructed on many of these barrier islands. Some of the gravel islands erode away after 

completion of exploratory drilling, spreading coarse sediments over a large area. Others, such as 

Seal Island, may be reused for development drilling. The gravel islands also may leach 

chemicals, particularly metals, from the gravel material used to construct the island, as happened 

at the Netserk F-40 Island exploratory drilling site in the Canadian Beaufort Sea (Crippen et al., 

1980). 

Floating platforms, such as drill ships, ice resistant platforms, such as the Kulluk, and 

occasionally semisubmersible rigs, are used for most exploration in deeper waters in the Arctic. 
15 

These drilling structures are anchored to the sea floor and may cause serious sea floor scour. 

Similar physical disturbance may be caused by pipeline emplacement. 

1.4.3 37BDrilling Waste Discharges 

Large volumes of wastes are generated during drilling of exploratory, production, and workover 

wells; some of these wastes may be permitted for discharged into the marine environment where 

they may cause ecological damage. The wastes produced in largest volumes during drilling are 

drilling muds and drill cuttings (Neff, 2010). Water based drilling muds (WBM) are the only 

types that have been used and discharged offshore in the Alaskan Beaufort Sea. Oil based 

drilling muds (OBM) and synthetic based drilling muds (SBM) have been used extensively in the 

Canadian Beaufort Sea and the associated drill cuttings have been discharged to the ocean. Some 

of these drilling wastes may have been carried into Alaskan Beaufort Sea waters by the 

prevailing westerly along-shore water currents. 

Modern WBM are composed of a weighting agent, usually barium sulfate (barite), clay or 

organic polymers, and small amounts of additives suspended in freshwater, seawater, or a saline 

brine. The WBM ingredients of major environmental concern are metals and petroleum 

hydrocarbons. The drill cuttings generated when drilling with WBM also may contain metals and 

hydrocarbons, derived mainly from the geologic strata being penetrated by the drill, and usually 

at concentrations similar to those in local marine sediments. The total estimated volume of WBM 

and cuttings discharged from each exploratory well drilled in the Beaufort Sea between 1981 and 

1997 ranged from about 940 to 2530 m3

/well (Table 1-3). 

The oil industry monitored environmental impacts of some of the exploratory drilling and 

development in the Alaskan Beaufort Sea. The results of these studies as well as studies of 

effects of offshore oil and gas development in other cold-water environments were reviewed 

recently by Neff (2010). If only water based drilling muds (WBM) and associated cuttings were 

discharged to these cold-water environments, environmental effects usually were minor and 

short-lived, consisting mainly of physical disturbance of benthic communities and accumulation 

of small amounts of several metals in sediments and benthic animals near exploratory platforms. 

1.4.4 38BProduction Waste Discharges 

Formation water usually is produced with fossil fuels during production; produced water may be 

treated to remove hydrocarbons and discharged to the ocean if local environmental regulations 

permit, adding chemical contaminants to the water column. Historically, produced water from 

onshore and offshore production wells has not been discharged to the Alaskan Beaufort Sea. 

Most is treated and reinjected, primarily for water-flood to enhance production of oil. 

1.4.5 39BBlowouts and Oil Spills 

Though rare, there is a risk of blowouts or oil/gas spills from offshore platforms during drilling 

and production. There was a total of 149 oil spills (>380 liters), releasing an estimated 556 

metric tons of crude oil, from offshore platforms to the US outer continental shelf between 1990 

and 1999 (National Research Council, 2003). The largest crude oil spills from offshore platforms 

were the 1979 Ixtoc I blowout in the Sonda Campeche, in the Mexican Gulf of Mexico and the 

2010 New Horizon oil spill in 1525 m of water in the US Gulf of Mexico off the Mississippi 

River. The Ixtoc 1 blowout began in June 1979 and lasted 295 days, resulting in the release of 
16 

Table 1-3. Estimated volumes of water based drilling mud and cuttings discharged to the 

Alaskan Beaufort Sea from exploratory wells for which information is available from 

Exploration Plans. Volumes are m3

 = 1000 liters or 264 gallons. From Neff (2010). 

Prospect Date Water 

Depth (m) Drilling Unit Discharge Method Estimated Volume (m3) 

Alaskan Beaufort Sea 

Beachy Pt. 1981 5.5 Gravel island Cuttings hauled to 

shore, injectedd 1590 

Tern 1982/1987 6.4 Gravel island To water per NPDES 

permit 2380 

Fireweed 1990 15 SDC/MATa To water per GP 

AKG284100 1590 

Antares 1984/1985 15 CIDSb To water per GP 1110 

Mars 1986 7.6 Spray ice island To sea ice per GP 1420 

Mukluk 1983 15 Gravel island To water under ice 

per NPDES permit 1110 

Harvard 1985 15 Gravel island To water or on ice 

per NPDES permit 1420 

Sandpiper 1986 15 Gravel island To water or on ice 

per NPDES permit 1420 

Belcher 1988 51 Kullukc Per GP; method not 

specified 2530 

McCovey 2002 11 SDC/MATa

To sea ice surface 

per GP 

AKG2842005 

939 

Liberty 1997 6.4 Gravel/ice island To sea ice surface 

per GP 1730 

Warthog 1997 11 CIDSb To sea ice surface 

per GP 1520 

Mean Volume 1445 

a

 SDC/MATT = Steel drilling caisson or steel drilling caisson/Mat drilling unit; b CIDS = Concrete island drilling 

unit; c These are ice-reinforced drilling rigs; d This exploratory well was drilled in winter when the gravel island was 

attached to shore by an ice road. Cuttings were transported to Prudhoe Bay for reinjection. Drilling muds were 

stored on the gravel island and reinjected into the well at the end of drilling.

approximately 500,000 metric tons of crude oil to the southern (Mexican) Gulf of Mexico 

(Boehm et al., 1983). The New Horizon blowout occurred on April 20, 2010 and was capped on 

July 5. During that time, approximately 700,000 metric tons of a light crude oil were released 

just above the sea floor (Crone and Tolstoy, 2010). Offshore oil spills, especially large ones, can 

cause serious environmental damage if the oil sinks to the sea floor or reaches the shore. The 

potential impacts of oil spills in Arctic marine environments, such as the Alaskan Beaufort and 

Chukchi Seas are largely unknown, but may be more serious than spills in temperate and tropical 

environments, because of the difficulty in managing oil spill response and cleanup/remediation 

in a seasonally ice-covered environment and the slower rate of microbial degradation of the oil in 

cold-water environments (Nuka Research and Planning Group LLC, 2007). 
17 

1.4.6 40BAir Emissions 

Fugitive and intentional (venting and flaring) emissions to the air may also occur during 

development drilling and production (OGP, 2000) and may result in release to the air of 

greenhouse gases (CO2, CH4, and N2O), non-greenhouse gases (SOx, H2S, NOx, and VOC), and 

petrogenic and pyrogenic hydrocarbons. Polycyclic aromatic hydrocarbons (PAH) are among the 

hydrocarbons emitted to the atmosphere by venting and flaring waste gases at production 

facilities. Approximately 500,000 million standard cubic feet (mscf) of natural gas was 

vented/flared at Northstar in 2001(AOGCC, 2004). This total rose to more than 1,100,000 mscf 

in 2002, the highest amount vented/flared in a single year between 2000 and 2004 at any oil and 

gas facility on the North Slope. Gas venting/flaring at Northstar declined to 162,321 mscf in 

2004, representing 3% of the total gas vented/flared on the North Slope in 2004 (5,459,844 

mscf). The PAH concentration in the flare exhaust is not known. Hydrocarbons, including PAH, 

also may be emitted in diesel exhaust and fugitive emissions from petroleum production, 

treatment, storage, and transportation facilities. Some of these flared or vented PAH may settle 

on the sea surface and eventually settle in sediments down-wind from the platform. 

1.4.7 41BWaste Disposal Near Northstar Production Facility 

Drilling muds and cuttings were not discharged to the Beaufort Sea during development of the 

Northstar facility. Some non-aqueous phase drilling muds (i.e., SBM and OBM) were used for 

development drilling at Endicott and Northstar and all drilling wastes were disposed of in waste 

disposal wells at the drill site or transported to shore for onshore disposal (Krieger et al., 2002). 

At Northstar Island, all drilling muds and cuttings, as well as other platform wastes, initially 

were trucked to shore over an ice road for on-land treatment and disposal. Subsequently, a 

reinjection well was drilled on the gravel island for disposal of development wastes. 

WBM and cuttings from the exploration and delineation wells drilled on and near Seal Island 

before construction of Northstar Island were discharged to the ocean. If it is assumed, based on 

the data in Table1-3 that approximately 1.5 million liters of WBM and cuttings were discharged 

from each of the five exploratory and delineation wells drilled at Seal Island between 1983 and 

1986, the total volume of mud and cuttings discharged was approximately 7.5 million gallons. 

 
18 

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19 

2 1BMETHODS 

Detailed descriptions of field study designs and field methods and laboratory analytical methods 

are included in the ANIMIDA and cANIMIDA final reports cited below. The sections that 

follow include brief summaries of field and analytical methods for each of the cANIMIDA tasks. 

2.1 10BStudy Designs and Field Methods 

2.1.1 42BSources and Partitioning of Metals and Hydrocarbons in the Beaufort Sea 

Field activities for cANIMIDA Tasks 3 and 4 included sampling rivers during spring breakup in 

May-June 2004 and 2006 (Figure 2-1), through ice sampling of the Beaufort Sea during spring 

floods in May-June 2004 and 2006, and sampling rivers and offshore waters during the openwater periods of July-August 2004, 2005 and 2006 (Figure 2-2) (Trefry et al., 2009). These tasks 

were a continuation of ANIMIDA Task 5 (Trefry et al., 2004a) and Task 7 (Trefry et al., 2004b) 

Figure 2-1. Map showing locations of sampling stations for the cANIMIDA Program in relation 

to locations of exploratory well sites and production facilities. The location of Cross 

Island where the subsistence whaling study was performed (cANIMIDA Task 7) also 

is shown. 
20

Figure 2-2. Sampling sites in Stefannsson Sound with inset map of Alaska showing study area

during May-June 2004. Causeways connecting the Seawater Treatment Plant (STP), 

Pt. McIntyre, and Endicott Island to shore are shown by the solid lines. Station 

numbers in ovals identify locations where ice cores also were collected. Arrows show 

approximate direction of primary river outflow. From Trefry et al. (2009).

that included sampling of rivers during spring breakup in May-June 2001 and 2002, through-ice 

sampling of the Beaufort Sea during spring floods of 2001 and 2002, and rivers and offshore 

waters during open-water periods of June-August 2000, 2001, and 2002.

The Sagavanirktok and Kuparuk Rivers were sampled daily during late May and June in 2004 

and 2006. Laboratory analyses included total suspended solids (TSS) and the following 

particulate metals: aluminum (Al), arsenic (As), barium (Ba), calcium (Ca), copper (Cu), iron 

(Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), 

zinc (Zn) and organic carbon. Concentrations of the following dissolved metals also were 

determined: As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb and Zn. 

Water and suspended sediments also were collected under the ice, seaward of the rivers during 

the early days of spring runoff in 2004 and 2006 when the coastal Beaufort Sea was still ice 
21 

covered. Vertical profiles of conductivity, temperature and turbidity were collected at each site 

along with samples for TSS, particulate metals, particulate organic carbon and dissolved metals. 

During the open-water period in 2004, 2005 and 2006, numerous vertical casts in the water 

column were made throughout the coastal Beaufort Sea to measure salinity, temperature and 

turbidity. Turbidity also was measured by in situ turbidimeter, by laboratory turbidimeter using 

discrete samples, and by filtration/gravimetry using discrete samples. Samples were analyzed for 

the same particulate and dissolved trace metals as listed above for rivers. 

2.1.2 43BHydrocarbon and Metal Characterization of Sediments in the ANIMIDA Study 

Area 

Field studies for cANIMIDA Task 2 included sampling sediments at stations in the Northstar, 

Liberty, and BSMP areas during the summers of 2004, 2005, and 2006 (Table 2-1; Figure 2-3) 

for chemical analysis (Brown et al., 2010). cANIMIDA Task 2 is a continuation of parts of 

ANIMIDA Task 2 (Brown et al., 2004) and the Phase 1 ANIMIDA Project (Boehm et al., 2001). 

Figure 2-3. Locations of the BSMP, Northstar, and Liberty stations sampled in the cANIMIDA 

Program in relation to exploratory drilling sites and production facilities. 
22 

Table 2-1. Station numbers, sorted by area, where sediment and invertebrate tissue samples were 

collected for chemical analysis in ANIMIDA (1999-2002) and cANIMIDA (2004-2006). 

Area Station 1999 2000 2002 2004 2005 2006 

Sed. Tiss.1 Sed. Tiss. Sed. Tiss. Sed. Tiss. Sed. Tiss. Sed. Tiss. 

BSMP 1A 1 C,I 

BSMP 1B 1 

BSMP 1C 22 A 

BSMP 1D 1 I 

BSMP 1E 1 C 

BSMP 2A 2 

BSMP 2B 1 

BSMP 2C 1 

BSMP 2D 1 

BSMP 2E 1 

BSMP 2F 1 A,C,I 

BSMP 2G 1 M 

BSMP 2H 1 

BSMP 3A 1 C 1 C 1 C 1 C,M 1 C 

BSMP 3B 1 1 1 1 1 

BSMP 4A 1 1 A 1 A 1 A 1 A 1 A 

BSMP 4B 1 1 1 1 1 A,I 

BSMP 4C 1 1 1 1 

BSMP 5(0) 1 1 A 1 A 1 A 

BSMP 5(1) 1 1 1 1 1 A,C,M 1 

BSMP 5(10) 1 1 1 1 

BSMP 5(5) 1 1 1 1 1 1 

BSMP 5(5A) 1 

BSMP 5A 1 1 1 1 1 M 

BSMP 5B 1 A 1 1 1 A 

BSMP 5D 1 1 1 1 

BSMP 5E 1 1 1 1 

BSMP 5F 1 C 1 C 1 C 1 C 

BSMP 5H 1 C 1 C 1 C 1 C,M C 

BSMP 6A 1 A 

BSMP 6B 1 A.I 

BSMP 6D 1 

BSMP 6F 1 A 

BSMP 6G 

BSMP 6H 

BSMP 7A 2 

BSMP 7C 1* 

BSMP 7E 2 A 

BSMP 7G 1 A 
23 

Table 2–1. Continued. 

Area Station 1999 2000 2002 2004 2005 2006

Sed. Tiss.1 Sed. Tiss. Sed. Tiss. Sed. Tiss. Sed. Tiss. Sed. Tiss. 

Liberty BP01 2 A,M 1 A,M 

Liberty E01 2 A,M 1 M 

Liberty E02 1 

Liberty L01 1 1 1 1 

Liberty L01A 1 

Liberty L02 1 1 

Liberty L03 1 1 1 C 

Liberty L04 1 A 1 1 1 A 

Liberty L05 1 1 

Liberty L06 1 1 1 1 M 

Liberty L06A 1 1 

Liberty L07 1 1 1 1 1 I 

Liberty L08 1 C 1 C 1 C 1 C 1 C,I,M A.C,I,

M 

Liberty L09 1 C 1 C 1 C 1 

Liberty L10 1 1 

Liberty L11 1 1 

Liberty L12 1 1 

Liberty L17 1 

Liberty L18 1 A 

Liberty L17B 2 

Liberty L19 1 A 

Liberty L20 1 

Liberty L21 1 

Liberty L22 2 

Northstar M01 1 

Northstar N01 1 1 1 1 

Northstar N02 1 1 1 1 

Northstar N03 1 1 A 1 A 1 A 1 A,M 1 A,M 

Northstar N04 1 1 1 A 1 A,M 1 

Northstar N05 1 1 1 1 M 1 

Northstar N05N11 I,My 

Northstar N06 1 1 1 1 M 1 1 A 

Northstar N07 1 1 1 1 

Northstar N08 1 1 1 1 1 

Northstar N09 1 1 1 1 

Northstar N10 1 1 1 1 

Northstar N11 1 A 1 1 1 A 1 A 1 A,M 

Northstar N11N08 A,I,My

Northstar N11S I,My 
24 

Table 2–1. Continued. 

Area Station 1999 2000 2002 2004 2005 2006 

Sed. Tiss.1 Sed. Tiss. Sed. Tiss. Sed. Tiss. Sed. Tiss. Sed. Tiss. 

Northstar N12 1 A 1 A 1 A 1 

Northstar N13 1 1 A 1 A 1 

Northstar N14 1 1 1 1 1 1 A 

Northstar N15 1 1 1 1 

Northstar N16 1 1 1 

Northstar N17 1 1 1 1* 

Northstar N18 1 A 1 A 1 1 A 

Northstar N19 1 1 1 

Northstar N20 1 1 1 

Northstar N21 1 1 1 

Northstar N22 1 

Northstar N23 1 1 1 

Northstar N25 M 

Northstar N26 2 A 

Northstar N27 A 

Northstar N28 1 A 

Other WD01 1 A,I,M 

Other SDI01 1 

1Tissue types: A= Amphipod, C=Clam, I=Isopod, M=Mussels, My=Mysids 

2Sediment samples: 1 = Grab, 2 = 1 Grab and 1 Core; 1*=Core only 

In ANIMIDA Task 2, sediments were sampled for chemical analysis at Northstar, Liberty, and 

BSMP stations during the summers of 2000 and 2002; sampling in ANIMIDA Phase 1 was 

performed in 1999 and represents the pre-development conditions at Northstar. ANIMIDA and 

cANIMIDA sampling stations are summarized in Tables 2-1 and 2-2. 

Table 2-2. Stations, sorted by area, where fish samples were collected for chemical analysis and 

biomarker assays in ANIMIDA (1999-2002) and cANIMIDA (2004-2006). Total number 

of fish samples (8 species sampled) collected at each station and year is included. From 

Spies et al. (2003) and Neff et al. (2009). 

Area Station 2001 2004 2005 2006 

Reference Bullen Point 25 

Reference Tigvariak Island 30 

Liberty L14 18 5 

Liberty L15 

Liberty PBS 27 26 18 20 

Northstar N25 7 5 

Northstar SIS 48 31 17 19 
25 

The focus of this monitoring was to identify and characterize the distribution and concentrations 

of chemical contaminants (metals and hydrocarbons) from the Northstar and Liberty 

developments in Beaufort Sea sediments. ANIMIDA Phase 1 sampling was intended to 

characterize the distribution of metals and hydrocarbons in sediments before construction of 

Northstar Island. ANIMIDA Task 2 was intended to characterize changes in sediment chemistry 

during and shortly after island construction and start-up of production. cANIMIDA Task 2 was 

intended to characterize long-term changes in sediment chemistry in Northstar, Liberty, and 

BSMP areas. All sediment samples were analyzed for saturated hydrocarbons (SHC), polycyclic 

aromatic hydrocarbons (PAH), and sterane/triterpane (StTr) hydrocarbon source biomarkers. 

Surficial sediment samples were collected using a modified Van-Veen grab sampler. During the 

collection and handling of sediment samples from the grab sampler, extreme care was taken to 

avoid contact with metal and hydrocarbon sources. Samples were taken away from the sides of 

the grab and metal spatulas were not used for the collection of trace metal samples. The grab 

sampler was protected from stack smoke, grease drips from winches and wire, and other 

potential airborne contamination during the sampling process. Sediment samples were collected 

from the top 1 cm of the grab to represent recent accumulation. Unconsolidated sediment 1 cm 

deep was removed from the grab with a stainless-steel scoop coated with Kynar or a Teflon

spatula. 

The sediment core sampling procedure included deployment of a dual-barrel gravity corer 

weighted with lead to allow “freefall” into the bottom to collect “side-by-side” cores for 

geochronology and chemistry. Polybutyrate core liners were placed within the metal barrels of 

the corer. After the cores were collected, the core liners were removed from the metal sleeves, 

sealed with plastic end caps and stored until returned to shore. 

2.1.3 4BIntegrated Biomonitoring and Bioaccumulation of Contaminants in Biota of the 

cANIMIDA Study Area 

Field studies for cANIMIDA Task 5 focused on sampling marine animals from the Northstar, 

Liberty, and BSMP areas during the summers of 2004, 2005, and 2006 (Tables 2-1 and 2-2; 

Figure 2-3) for chemical analysis (Neff et al., 2009). Biological samples were collected during 

field surveys performed during the summers of 2004, 2005, and 2006 at a subset of the stations 

sampled for sediment chemistry in cANIMIDA Task 2. cANIMIDA Task 5 is a continuation of 

parts of ANIMIDA Phase 1 (Boehm et al., 2001), ANIMIDA Task 2 (Brown et al., 2004) and 

ANIMIDA Task 8 (Spies et al., 2003). Sampling station stations for marine invertebrates during 

ANIMIDA and cANIMIDA are summarized in Table 2-1. Sampling sites for fish are 

summarized in Table 2-2. 

Task 5 of cANIMIDA focused on an assessment of concentrations of petroleum hydrocarbons, 

including PAH, SHC, StTr petroleum biomarkers, and 13 to 19 metals in soft tissues of 

representative species of marine bivalve mollusks, crustaceans, and fish from the offshore areas 

in the Alaskan Beaufort Sea near ongoing or planned oil and gas development activities. 

Biological samples were collected at several sampling stations near the Northstar production 

facility, the Liberty prospect, and at reference locations, mostly east (up-current) of development 

activities (the BSMP stations). Five different types of biological samples were collected during 

cANIMIDA; semi-permeable membrane devices (SPMDs) were deployed only in 2004 to 
26 

estimate concentrations of dissolved PAH in the water column. Indigenous clams (Astarte 

montagui and Cyrtodaria kurriana), amphipods (usually Anonyx nugax), and fish were collected 

locally. Caged blue mussels (Mytilus trossulus) were collected from Port Chatham in southern 

Cook Inlet and deployed for approximately two weeks at stations near Northstar and in the 

Liberty and BSMP areas. During all three years, isopods (Saduria sabini) were collected 

whenever available; mysids (Mysis sp) were collected opportunistically in 2006. Amphipods and 

clams also were collected in 1999, 2000, and 2002 as part of the ANIMIDA Project. Station 

locations where each invertebrate species was collected in 1999 through 2006 are summarized in 

Table 2-1. 

Eight species of fish were collected one or more times in 2004, 2005, and 2006 at different 

locations in the study area in the Beaufort Sea (Table 2-2) for analysis of hydrocarbons and 

metals in whole tissues and for measurement of the biomarkers of PAH exposure, cytochrome 

P450A mixed function oxygenase (CYP1A) activity in selected tissues and fluorescent aromatic 

compounds (FACs) in bile. CYP1A and bile FAC analyses were preformed on fish tissue 

samples collected in 2004 and 2005, but not 2006. The following species were analyzed for 

PAH, 13 metals, and PAH exposure biomarkers: 

 Arctic char (Salvelinus alpinus) 

 Arctic cisco (Coregonus autumnalis) 

 Least cisco (C. sardinella) 

 Broad whitefish (C. nasus) 

 Humpback broad whitefish (C. pidschian) 

 Arctic cod (Boreogadus saida) 

 Arctic flounder (Liopsetta glacialis) 

 Four horn sculpin (Myoxocephalus quadricornis) 

2.1.4 45BLong-Term Monitoring of the Kelp Community in the Stefansson Sound 

Boulder Patch: Detection of Change Related to Oil and Gas Development 

Field studies for cANIMIDA Task 6 focused on monitoring water quality, light intensity, kelp 

growth, and biodiversity in the associated invertebrate community in Stefansson Sound Boulder 

Patch (Dunton et al, 2009). Stefansson Sound is about 20 km northeast of Prudhoe Bay and 

immediately east of the Endicott production facility (Figure 2-4). The Liberty prospect is in 

southwestern Stefansson Sound. The sound extends from the Midway Islands in the west to 

Tigvariak Island in the east and is enclosed by a barrier island chain to the North, including 

Cross Island, the site of the fall Nuiqsut subsistence bowhead whale harvest. Boulders and 

cobbles cover large areas of the silt-clay sediments in the sound; these boulder fields are called 

the Stefansson Sound Boulder Patch. The field surveys were performed during the summers of 

2004, 2005, and 2006. cANIMIDA Task 6 is a continuation of ANIMIDA Task 6 that monitored 

the Boulder Patch in the summers of 2001, 2003, and 2003 (Dunton et al., 2004). 
27 

Figure 2-4. Map of the cANIMIDA 2004 - 2006 project study area showing the location of the 

30 synoptic collection sites used in summers 2004, 2005 and 2006. The thin lines 

outline the areas containing boulders. SDI: Satellite Drilling Island. 
28 

Three sampling strategies were used in summers 2004, 2005 and 2006: 

 semi-synoptic maps of total suspended solids (TSS) and light attenuation parameters 

were generated through sampling at 30 randomly-selected points in a 300 km2 area that 

included the Boulder Patch and the region south of Narwhal Island to the Sagavanirktok 

Delta; 

 long-term variations in underwater photosynthetically active radiation (PAR) were 

monitored at three fixed sites and incident PAR at one coastal site during the summer 

open-water period; 

 benthic faunal diversity was measured at seven monitoring stations established during the 

1984-1991 Boulder Patch Monitoring Project (LGL Ecological Research Associates and 

Dunton, 1992). 

In addition to simultaneous measurements of PAR and TSS, other parameters measured 

included water column chlorophyll, ammonium, phosphate, silicate, nitrate + nitrite, temperature, 

salinity, dissolved inorganic nitrogen, and pH. 

2.1.5 46BContinuation of Annual Assessment of Subsistence Bowhead Whaling Near 

Cross Island as part of the cANIMIDA Project 

cANIMIDA Task 7 is a continuation of ANIMIDA Task 4. Field work for ANIMIDA Task 4 

was performed during the fall (September) subsistence bowhead whale hunt at Cross Island in 

2001, 2002, and 2003 (Galginaitis and Funk, 2004). Field work for cANIMIDA Task 7 was 

performed at Cross Island in the fall of 2001 through 2007 (Galginaitis, 2009). 

These tasks focused on monitoring potential effects of offshore development on subsistence 

whaling near Cross Island by the residents of the village of Nuiqsut. Three primary methods of 

information collection were employed – systematic observations, collection of daily vessel 

location information during each hunt from handheld GPS units, and whalers’ self-reports and 

perceptions. All whaling boats were given handheld GPS units that recorded their tracks during 

searches for whales and significant point locations. Debriefing of whalers by talking with them 

while examining these tracks on a computer screen after they came back from their hunt was also 

an important source of information. 

2.2 1BAnalytical Methods 

2.2.1 47BWater Chemistry 

Salinity of water samples was measured in the field with a conductivity probe; in the laboratory 

salinity was calculated from chlorinity measured by Mohr titration. River water chlorinity (Cl-

), 

sulfate (SO4

2-) and fluoride (F-

) concentrations were determined by ion chromatography with a 

Dionex DX-600 ion chromatograph (IC). Alkalinity was determined by titration using the 

method of Strickland and Parsons (1972). 

Concentrations of dissolved silica, phosphate, and nitrate were determined by standard methods 

within 48 hours of collection. Concentrations of 18O were determined in 62 water samples from 

key under-ice stations in spring 2004 that were selected based on salinity and dissolved silica 

values. Analyses for 18O were performed with a VG Micromass gas source stable isotope ratio 

mass spectrometer. 
29 

Samples for particulate organic carbon (POC) and dissolved organic carbon (DOC) were 

prepared by filtration of seawater and river water through pre-combusted Gelman Type A/E 

glass fiber filters mounted on acid-washed filtration glassware within a Class-100 laminar-flow 

hood. The filters containing POC were treated with H3PO4 to remove inorganic carbon phases, 

rinsed with distilled water, dried and their particulate mass determined. The filters were 

combusted at 900°C to measure POC. The DOC concentrations in the seawater and river water 

samples were calculated by difference, total carbon (TC) minus inorganic carbon (IC) as 

determined by combustion. 

2.2.2 48BAnalysis of Metals in Water, Sediments, and Tissues 

Detailed descriptions of analytical methods for metals in water, sediment, and tissues of marine 

animals, as well as a complete discussion of laboratory quality control, are in three cANIMIDA 

final reports (Brown et al., 2010; Neff et al., 2009; and Trefry et al., 2009). All metals analyses 

were performed in the laboratory of John Trefry at Florida Institute of Technology, Melbourne, 

FL. A brief summary of the analytical methods is given here. 

Concentrations of dissolved As, Cd, Cr, Cu, Pb and Zn in seawater and riverwater were 

determined on extracts obtained using a reductive precipitation procedure. Ultra-high purity Pd, 

Fe and NaBH4 were used to precipitate the metals that were then collected by filtration and 

redissolved in ultra-high purity HNO3 and HCl. Concentrations of dissolved Ba were determined 

directly on diluted aliquots of the seawater samples. River water samples were analyzed directly 

for Ba, Ca, Cu, Fe, K, Mg, Mn, Na and Ni as described below. Concentrations of Pb and Zn in 

river water were determined by reductive precipitation of the water sample and a certified 

reference material (CRM). 

Total dissolved Hg concentrations in seawater and river water were determined on separate 

aliquots of water that had been treated with bromine monochloride solution to oxidize organic 

ligands and preserve the samples until analysis. Mercury in water samples was preconcentrated 

by gold amalgamation followed by analysis with CVAFS in a Brooks-Rand Model III Mercury 

System. 

The metal concentrations of the river water, river water extracts, seawater extracts, CRMs, and 

blanks were determined by FAAS, GFAAS, ICP-MS or cold-vapor atomic fluorescence 

spectrometry (CVAFS) (Table 2-3). Analytical methods for some metals were slightly different 

for river water and seawater extracts. 

Filters bearing field samples of suspended sediments, as well as separate milligram quantities of 

a standard reference material (SRM), were digested in stoppered, 15-mL Teflon test tubes with 

Ultrex II HNO3, HF and HCl. Refluxing of the acids at 80°C completely dissolved the particles 

on the filters. Metal concentrations for the digested particulate samples, SRMs and blanks were 

determined by flame atomic absorption spectrometry (FAAS), graphite furnace atomic 

absorption spectrometry (GFAAS) or inductively coupled plasma mass spectrometry (ICP-MS) 

(Table 2-3). 

Selected sediment core samples also were analyzed for excess 210Pb and total 137Cs in an effort to 

determine whether sediment at a particular location was recently deposited. Sediment core 

samples were sub-sectioned in 0.5-cm intervals in an effort to age-date the cores. Sediment 

samples were freeze-dried and ground to a fine powder. The samples were then set aside for at 
30 

Table 2-3. Summary of instrumental methods and method detection limits (MDL) for analysis of 

metals in water, suspended sediments, sediments, and soft tissues of marine animals. 

Concentrations are μg metal/g dry sediment or mg/L (parts per million). From Brown et 

al. (2009), Neff et al. (2009), and Trefry et al. (2009). 

Metal Method 

Method Detection Limit (MDL) 

Water Suspended 

Sediment Sediment Tissue 

Silver (Ag) ICP-MS 0.007 

ZGFAAS 0.004 

Aluminum (Al) FAAS 1500 10 2.3 

Arsenic (As) 

GFAAS 0.0000081 1.8 

ZGFAAS 0.012 

ICP-MS 0.02 

Barium (Ba) 1CP-MS 0.0001 9 0.01 0.01 

Beryllium (Be) ICP-MS 0.009 0.001 

Calcium (Ca) FAAS 0.01 230 

Cadmium (Cd) ICP-MS 0.0000001 0.03 0.001 0.001 

Cobalt (Co) ZGFAAS 0.001 

ICP-MS 0.001 

Chromium (Cr) FAAS 0.33 1.0 0.01 

GFAAS 0.000005 

Copper (Cu) FAAS 0.4 2 0.7 

GFAAS 0.000003 

Iron (Fe) FAAS 250 10 2.5 

GFAAS 0.00001 

Potassium (K) FAAS 0.02 250 

Mercury (Hg) CVAAS 0.00003 0.001 0.001 

Magnesium (Mg) FAAS 0.01 40 

Manganese (Mn) FAAS 170 2 1.1 

GFAAS 0.0001 

Sodium (Na) FAAS 0.008 0.7 

Nickel (Ni) ICP-MS 0.00002 0.2 0.004 0.004 

Lead (Pb) ICP-MS 0.000002 82 0.002 0.001 

Antimony (Sb) ICP-MS 0.001 0.001 

Selenium (Se) ZGFAAS 0.03 

Thallium (Tl) ICP-MS 0.001 0.001 

Vanadium (V) FAAS 10 0.002 

Zinc (Zn) FAAS 2.0 0.5 0.4 

ICP-MS 0.00001 

Analytical methods: CVAAS = Cold Vapor Atomic Absorption Spectrometry 

 FAAS = Flame Atomic Absorption Spectrometry 

 GFAAS = Graphite Furnace Atomic Absorption Spectrometry 

 ICP-MS = Inductively Coupled Plasma-Mass Spectrometry 

 ZGFAAS = Zeeman Graphite Furnace Atomic Absorbtion Spectrometry 
31 

least 20 days to establish secular equilibrium and the activities of the various radionuclides were 

then determined by counting. Sediment geochronology was determined using excess 210Pb and 

137Cs following methods described by Kang et al. (2000). Vials containing about 10 g of freezedried sediments were counted for 2 to 3 days until peak areas were sufficient to provide <10% 

counting error for total 210Pb. The activities of 210Pb, 214Pb, 214Bi and 137Cs were determined with 

a well-type, intrinsic germanium detector. 

Freeze-dried samples of marine animal tissues were digested by a sequential addition of 

concentrated, high-purity nitric acid (HNO3), hydrogen peroxide (H2O2), and hydrochloric acid 

(HCl). Tissue subsamples for mercury analysis were digested with concentrated, high-purity 

nitric acid (HNO3) and sulfuric acid (H2SO4) and refluxed in the sealed extraction tubes. 

Metal concentrations in the digested tissue samples and associated quality control samples were 

determined by FAAS, GFAAS (Zeeman or Continuum background correction), CVAAS, or ICPMS (Table 2-3). 

2.2.3 49BSediment Grain Size and Total Organic Carbon (TOC) 

Grain size analyses of sediments were performed by the classic method of Folk (1974) that 

includes a combination of wet sieving and pipette techniques. Total organic carbon (TOC) 

analyses of sediments were performed by a combustion method described by Froelich (1980) for 

the analysis of organic carbon in marine sediments. 

2.2.4 50BAnalysis of Saturated Hydrocarbons (SHC), Polycyclic Aromatic Hydrocarbons 

(PAH), and Sterane/Triterpane Petroleum Biomarkers (StTr) 

Detailed descriptions of analytical methods for PAH, SHC, and StTr in sediments and tissues of 

marine animals, as well as a complete discussion of laboratory quality control, are in two 

cANIMIDA final reports (Brown et al., 2010; Neff et al., 2009). All hydrocarbon analyses in the 

cANIMIDA Project were performed at the Battelle environmental chemistry laboratory in 

Duxbury, MA. Hydrocarbon analysis of some samples in the ANIMIDA Project were performed 

at Arthur D. Little, Inc., in Cambridge, MA. A brief summary of the analytical methods is given 

here. 

Dry sediment and tissue samples were extracted by serial solvent extraction method designed to 

more accurately measure trace-levels of PAH and other petroleum hydrocarbons in the samples. 

All samples were spiked with representative surrogate compounds (Tables 2-4, 2-5, and 2-6) and 

serially extracted three times with dichloromethane (DCM). Between extractions the samples 

were centrifuged to facilitate solvent removal and the extract was decanted into an Erlenmeyer 

flask. The extracts are then treated with sodium sulfate to remove water and concentrated on a 

water bath. 

Sediment and tissue samples were analyzed for PAH, SHC, and StTr and, therefore, were 

fractionated to remove potential interference and improve the quality of the low-level analysis. 

The sample extracts were loaded on an alumina clean up column and eluted with 

dichloromethane. The eluate was concentrated and an aliquot was removed for lipid weight 

determination. The remaining extract was fractionated on a silica gel column to isolate the PAH, 

SHC and StTr fractions. The column was eluted first with hexane (F1 fraction), followed by a 

mixture of hexane and methylene chloride (F2 fraction). The F1 fraction was spiked with 
32 

recovery internal standards for SHC and StTr analysis (Tables 2-5 and 2-6), divided into two 

aliquots and analyzed for SHC by gas chromatography with flame ionization detection (GC/FID) 

and for StTr by gas chromatography-mass spectroscopy (GC/MS). The F2 fraction was spiked 

with PAH recovery internal standards (Table 2-4) and analyzed by GC/MS. 

Table 2-4. Target polycyclic aromatic hydrocarbons (PAH) analyzed in sediments and soft 

tissues of marine animals collected in the ANIMIDA and cANIMIDA program from the 

Beaufort Sea. The C prefix for alkyl PAH indicates the number of alkyl carbons. Each 

alkyl-PAH isomer group is the total of all quantified isomers. Reporting codes are used in 

graphic presentation of PAH data. The MDL for individual PAH or alkyl-PAH isomer 

groups ranged from 1.2 to 4.7 ng/g dry wt. 

Compound Reporting 

Code Compound Reporting Code 

Naphthalene N C2-Fluoranthenes/Pyrenes C2FLU/PYR 

C1-Naphthalenes C1N C3-Fluoranthenes/Pyrenes C3FLU/PYR 

C2-Naphthalenes C2N Benzo[a]anthracene BaA 

C3-Naphthalenes C3N Chrysene C 

C4-Naphthalenes C4N C1-Chrysenes C1C 

Biphenyl BIP C2-Chrysenes C2C 

Acenaphthene ACE C3-Chrysenes C3C 

Acenaphthylene ACY C4-Chrysenes C4C 

Fluorene F Benzo[b]fluoranthene BbFLU 

C1-Fluorenes C1F Benzo[k]fluoranthene BkFLU 

C2-Fluorenes C2F Benzo[e]pyrene BeP 

C3-Fluorenes C3F Benzo[a]pyrene BaP 

Anthracene A Perylene PER 

Phenanthrene P Indeno[1,2,3-c,d]pyrene IcdPYR 

C1-Phenanthrenes/Anthracenes C1P Dibenzo[a,h]anthracene DBahA 

C2-Phenanthrenes/Anthracenes C2P Benzo[g,h,i]perylene BghiP 

C3-Phenanthrenes/Anthracenes C3P Total PAH TPAH 

C4-Phenanthrenes/Anthracenes C4P Surrogate Compounds 

Dibenzothiophene DBT Naphthalene-d8 

C1-Dibenzothiophenes C1DBT Acenaphthene-d10 

C2-Dibenzothiophenes C2DBT Phenanthrene-d10 

C3-Dibenzothiophenes C3DBT Benzo(a)pyrene-d12 

Fluoranthene FLU Internal Standard 

Pyrene PYR Fluorene-d10 

C1-Fluoranthenes/Pyrenes C1FLU/PYR Chrysene-d12 

The GC/MS analysis of the F1 and F2 fractions for StTr and PAH was performed by a 

modification of USEPA Method 8270 that included additional target compounds (e.g., alkyl 

PAH and hydrocarbon biomarkers), and obtained lower detection limits and better specificity by 

operating the detector in the selected ion monitoring (SIM) mode. Analytical instruments were 
33 

calibrated before sample analysis with a 5-point calibration (minimum) and varying level check 

standards were analyzed every 10 samples bracketing field and quality control sample analysis. 

A North Slope crude reference oil, North Star control oil, and a series of other quality control 

(QC) samples were analyzed with the samples. A PAH independent check QC sample also was 

analyzed. 

Table 2-5. Target saturated hydrocarbons (SHC), including the n-C9 through n-C40 normal 

alkanes, pristane, phytane and selected isoprenoids, analyzed in sediments and soft tissues 

of marine animals in the ANIMIDA and cANIMIDA Programs. The MDL for individual 

saturated hydrocarbons ranged from 40 to 190 ng/g dry wt. 

nC8 (optional) 1650 nC23 nC33

nC9 nC16 nC24 nC34

nC10 nC17 nC25 nC35

nC11 Pristane nC26 nC36

nC12 nC18 nC27 nC37

nC13 Phytane nC28 nC38

1380 nC19 nC29 nC39

nC14 nC20 nC30 nC40

1470 nC21 nC31 Total SHC 

nC15 nC22 nC32

Table 2-6. Target sterane and triterpane (StTr) petroleum biomarkers analyzed in sediments and 

soft tissues of marine animals collected in the ANIMIDA and cANIMIDA program from 

the Beaufort Sea. Reporting codes are used in graphic presentation of PAH data. The 

MDL for individual StTr ranged from 0.01 to 4.7 ng/g dry wt. 

Compound Reporting 

Code Compound Reporting Code 

C23-Diterpane T4 13β,17α-Diacholestane-20S S4 

C29-Tricyclictriterpane T9 13β,17α-Diacholestane-20R S5 

C29-Tricyclictriterpane T10 5α,14α,17α,24-Methylcholestane20R S24 

18α(H)-22,29,30-Trisnorhopane-TS T11 5α,14α,17α,24-Ethylcholestane-20S S25 

17α(H)-22,29,30-Trisnorhopane-TM T12 5α,14α,17α,24-Ethylcholestane20R S28 

17α(H),21β(H)-30-Norhopane T15 Unidentified Ethylcholestane S28a 

18α(H)-Oleanane T18 Surogate Compound 

17α(H),21β(H)-Hopane T19 

22S-17α(H),21β(H)-30-Homohopane T21 5b(H)-Cholane 

22R-17α(H),21β(H)-30-Homohopane T22 

The concentrations of the individual PAH target compounds were calculated versus the internal 

standards that were spiked into the sample prior to analysis. The target compound concentrations 

were corrected for surrogate recoveries to best represent the original sample concentration. The 

PAH concentrations were quantified using average relative response factors (RRF) generated 
34 

from the five point calibration. The RRF of the alkyl homologues were based on the RRF of the 

parent compound for each alkyl homologue series. 

The concentrations of all identified StTr were calculated versus the internal standard chrysened12. All target triterpane concentrations were quantified using the average relative response 

factor of 17b(H), 21b(H)-hopane (T23) generated from the initial calibration. All target sterane 

concentrations were quantified using the average relative response factor of cholestane (S17) in 

the initial calibration. The target compound concentrations were corrected for surrogate 

recovery. Surrogate recovery of 5β(H)-cholane was calculated relative to the internal standard. 

F1 fractions were analyzed by GC/FID to determine concentrations of SHC. Instrumental 

methods, maintenance, and QC procedures for the GC/FID analysis of samples were performed 

by a modification of USEPA Method 8015. Analytical instruments were calibrated before 

sample analysis with a 5-point calibration (minimum) and check standards bracketed the 

analytical run of field and quality control samples. 

The n-C9 through n-C40 normal alkanes, pristane, phytane and selected isoprenoids were 

determined in the extract (Table 2-5). The total (resolved and unresolved) saturated 

hydrocarbons (TSHC) also were determined. A reference sample of North Slope crude oil was 

analyzed with the samples. Quantification of the compounds was based on the internal standard 

compound (d62-triacontane) that was spiked into the sample just prior to analysis. The target 

compound concentrations were corrected for surrogate recovery. 

2.2.5 51BAnalysis of CYP1A Activity and Bile Fluorescent Aromatic Compounds (FAC) 

in Fish 

Bile samples were collected from several species of fish collected in 2004 and 2005, but not 

2006 and analyzed for fluorescing aromatic compounds (FACs). FAC concentrations were 

quantified by HPLC- fluorescence spectroscopy, with the detector excitation and emission 

wavelengths optimized for separate analysis of naphthalene-equivalent, phenanthrene-equivalent, 

and benzo(a)pyrene-equivalent metabolites. 

Fish tissues or whole fish (small specimens) collected in 2004 and 2005 at Beaufort Sea stations 

were fixed in formalin in the field for analysis by immunohistochemistry for CYP1A activity. 

The immunohistochemical method for CYP1A staining was described by (Smolowitz et al., 

1991). 
35 

3 2BRESULTS 

3.1 12BSources of Suspended Sediments, Metals, and Hydrocarbons in the Coastal 

Beaufort Sea 

On the Alaskan North Slope, the frozen tundra and snow pack upstream begin to melt during 

spring and meltwater slowly flows downstream (northward), melting the river water en route. 

The meltwater carries particulate and dissolved components frozen in the ice and snow from the 

previous year along with weathered rock and soil layers from the surrounding river banks. This 

thawing and weathering contribute to the specific chemical compositions of the particulate and 

aqueous phases carried by each river. During high discharge, that lasts only 1 to 2 weeks, 

Alaskan Arctic rivers typically transport 40 to 80% of their total annual discharge of water and 

>80% of their load of suspended sediments (Rember and Trefry, 2004). 

Spring floods under-ice were tracked during 2004 and 2006 in Stefansson Sound, a small and 

shallow area (average water depth <15 m) located offshore of the North Slope of Alaska and 

partially protected by barrier islands that separate it from the Beaufort Sea. Seasonal landfast ice 

(~2 m thick) that covers the area from October through April begins to melt in late May and 

eventually breaks up and blows offshore in July (Weingartner and Okkonen, 2001). During the 

spring melt, Alaskan Arctic rivers, including the Sagavanirktok River, flow at maximum 

discharge above and below the landfast ice. The ambient shelf water has a salinity that ranges 

from 28 ‰ (July-September) to 34 ‰ (mixing with brine drainage during ice formation in 

winter) with spring salinity of 31 to 32 ‰ and temperatures of -1.6 to -1.8C that increase to as 

high as 4C during the summer open water period (Weingartner and Okkonen, 2001). This shelf 

water is referred to here as the Polar Mixed Layer (PML), a term adopted from MacDonald et al. 

(1989). Circulation in the study area varies with the season as the presence of the ice determines 

the influence of winds on water movement. The area has a tidal range of ~0.2 m with currents 

that range from <1 to 24 cm s-1 and average 2 cm s-1, with <10% of the current magnitudes >10 

cm s

-1 during the landfast ice period (Matthews, 1981; Weingartner and Okkonen, 2001). 

3.1.1 52BTransport of Water, Sediments, and Chemicals from North Slope Rivers during 

the Spring Melt 

3.1.1.1 94BWater and Sediment Transport from Rivers During the Spring Melt 

During the 2 to 3 weeks of the spring floods in May-June, about 60% of the annual water flow 

from the Kuparuk River and about one third of the annual flow of the Sagavanirktok River are 

carried to the Beaufort Sea (Rember and Trefry, 2004). Although the overall trends in annual 

flow are similar, inter-annual variations and differences between rivers are observed in 

hydrographs during the spring melt (Figure 3-1). 

The Kuparuk River can be categorized as a tundra stream with most of the water derived from 

the tundra and foothills, not the mountains. Water and sediment discharge from the Kuparuk 

River usually occurs as a brief event (3-5 days) when upstream ice jams break up and allow a 

large pulse of water to pass down the river. The date of peak flow can vary by up to a month 

(Figure 3-1). 
36 

Figure 3-1. Hydrographs during the spring floods in 2001, 2002, 2004 and 2006 for the Kuparuk 

and Sagavanirktok rivers. Data from U.S.G.S. can be accessed at 

Uhttp://waterdata.usgs.gov/ak/nwisU. 
37 

The Sagavanirktok and Colville rivers can be classified as mountain streams that drain 

snowfields and glaciers in the Brooks Range. Peak flow, though quite pronounced, tends to 

extend over a longer time period than observed in the Kuparuk River (Figure 3-1). The dates of 

peak flow in the Kuparuk and Sagavanirktok Rivers coincided within just a few days (Figure 3-

1). However, the annual discharge of the Sagavanirktok River has increased by about 50% over 

the past 3 decades, probably caused by increased precipitation in the headwaters in the Brooks 

Range. There has been no discernable change in water flow of the Kuparuk River, which drains 

the tundra, over a similar time period. Concentrations of total suspended solids (TSS) in the 

spring flow water from the Sagavanirktok and Kuparuk Rivers in 2001, 2002, 2004, and 2006 

and from the Colville River in 2001 and 2006 were highly variable both among years and within 

each annual spring flood (Table 3-1). TSS concentrations were highest in the Colville River and 

lowest in the Kuparuk River. Concentrations varied on a daily basis. Thus, the suspended matter 

load in the river water that was moving offshore under the ice varied on a daily basis. All TSS 

concentrations in rivers during summer were 10 to >300 times lower than during the spring melt. 

About 90% of the annual transport of TSS from the rivers occurs during the spring floods. 

Table 3-1. Mean, maximum and minimum concentrations of total suspended solids (TSS) in the 

Kuparuk, Sagavanirktok and Colville Rivers during May-June of the years listed. From 

Trefry et al. (2009). 

River and Year n 

TSS – Mean 

(mg/L) 

TSS – Max. 

(mg/L) 

TSS- Min. 

(mg/L) 

Kuparuk 2006 10 25 60 4.6 

 2004 8 60 106 32 

 2002 14 19 120 0.5 

 2001 10 27 67 1.8 

Sagavanirktok 2006 13 130 353 9.5 

 2004 11 127 285 43 

 2002 26 92 244 3.5 

 2001 27 158 609 14 

Colville 2006 3 722 785 637 

 2001 13 343 545 42 

3.1.1.2 95BParticulate Metals and Organic Carbon in River Water 

The composition of suspended matter in rivers can provide a geochemical signature that may 

allow differentiation between incoming natural suspended sediments and anthropogenic 

contributions from industrial activity in the coastal Beaufort Sea. Furthermore, changes in the 

composition of the river-borne particles may help identify future shifts in mechanical and 

chemical weathering in the Brooks Range and across the North Slope that may be related to 

changing climate and other processes. 

Concentrations of Al in suspended sediments were highest in the Colville and lowest in the 

Kuparuk River. However, Ca concentrations were about 8 to 10 times higher in Sagavanirktok 

River suspended sediments than in those from the Kuparuk or Colville Rivers (Figure 3-2). 
38 

Figure 3-2. Concentrations of calcium (Ca) versus aluminum (Al) for suspended sediments from 

the Sagavanirktok (circles), Kuparuk (diamonds), and Colville (triangles) Rivers 

during 2001, 2002, 2004 and 2006. Markers show means and lines show standard 

deviations. From Trefry et al. (2009). 

These differences are directly related to the greater abundance of aluminum-bearing phases (clay 

minerals) in the Colville River relative to the Sagavanirktok and Kuparuk Rivers, as well as the 

much greater abundance of particulate calcite (CaCO3) and dolomite (CaMg(CO3)2 in the 

Sagavanirktok River. Unfortunately, the differences in the Ca/Al ratios among suspended 

sediments from the three rivers were not readily observed in coastal sediments, because of the 

presence of particulate calcite from marine invertebrate shells in coastal sediments. 

There also were differences in K and Mg concentrations in river suspended sediments. 

Concentrations were slightly higher in suspended sediments from the Colville River than in those 

from the other two rivers. However, there was a good correlation between both K and Mg and Al 

for all river suspended sediments. This trend suggests that the source minerals bearing K (most 

likely illite clays with some micas and potassium feldspars) are similar enough for each river that 

the linear variations are due to differences in the relative amounts of K phases in the suspended 

sediments. A similar relationship between Mg and Al supports common source minerals, such as 

chlorite, Mg(ClO2)2, for Mg. 

Concentrations of trace metals in river suspended matter provide another possible point of 

reference for differentiating among river sources of sediment and for comparison with bottom 

sediment in the cANIMIDA study area. Such comparisons may enable us to determine whether 

incoming suspended particles have been modified by chemical processes in marine sediments or 

if metal concentrations in marine sediments have been enhanced by anthropogenic inputs. 

Mean concentrations of particulate Ba, Cu, Fe, Ni and Pb in the Colville River averaged ~20 to 

~50% higher than concentrations in suspended particles from the Sagavanirktok and Kuparuk 

rivers (Table 3-2). However, suspended sediments from the Colville River also contained higher 

concentrations of Al, suggesting that suspended sediments in the Colville River, originating 

Al (%)

0 2 4 6 8 10

Ca(%)

0

2

4

6

8

10

12

Sagavanirktok

Colville Kuparuk
39 

farther to the west in the Brooks Range, have been more thoroughly sorted during transport, 

resulting in enrichment of metal-rich fine-grained aluminosilicates relative to coarser nonaluminosilicate minerals than suspended sediments in the other two rivers. 

When concentrations of particulate Fe were plotted versus Al (Figure 3-3), the results for the 

Sagavanirktok River fit the same Fe/Al trend reported for sediments in the coastal Beaufort Sea 

(Trefry et al., 2003). Concentrations of Fe were as much as ~10% higher than predicted from the 

Beaufort Sea sediment data in most of the suspended sediment samples from the Kuparuk and 

Colville rivers. Higher concentrations of dissolved Fe in the Kuparuk and Colville Rivers may 

enhance the formation of insoluble Fe hydrous oxides, increasing concentrations of particulate 

Fe as described by Rember and Trefry (2004). 

More than 85% of the data points for Ba, Cu, Cr, Ni and Pb in suspended sediments from the 

three rivers during 2004 and 2006 plotted below the upper prediction intervals on the metal 

versus Al graphs, as shown for the plot of Ba versus Al concentrations in river suspended 

sediments (Figure 3-4). The higher metal concentrations, that plotted at <25% above the upper 

prediction interval, were from the Kuparuk River that usually contained lower concentrations of 

TSS with more variable metal concentrations than the other rivers (Table 3-2). Some of the 

observed anomalies in metal/Al ratios for Ba, Cu, Cr, Ni, Pb, and Zn may be due to 

anthropogenic inputs of metals from industrial activities on the North Slope. With the large data 

base from 2001 to 2006, river particles may provide a useful long-term tool for monitoring inputs 

of metals from land to the cANIMIDA study area. 

Table 3-2. Mean and range of concentrations of metals and total particulate organic carbon 

(POC) in suspended sediments collected in the Kuparuk and Sagavanirktok Rivers in the 

spring (May-June) of 2001-2, 2004, and 2006 and in the Colville River in the spring of 

2001 and 2006. Concentrations are % or μg/g (parts per million) on a dry-weight basis. 

From Trefry et al. (2009). 

Metal Kuparuk R. (2001-2, 

2004, 2006) 

Colville R. (2001, 

2006) 

Sagavanirktok R. 

(2001-2, 2004, 2006) 

Aluminum (Al) (%) 5.0 (2.6 - 7.5) 8.0 (7.5 - 8.9) 6.0 (4.0 - 8.8) 

Arsenic (As) (μg/g) 11.6 (3.9 - 29.7) 12.2 (10.2 - 15.3) 11.1 (4.7 - 24.5) 

Barium (Ba) (μg/g) 591 (358 - 1219) 964 (887 - 1190) 652 (433 - 1110) 

Calcium (Ca) (%) 0.9 (0.6 - 2.2) 0.8 (0.58 - 1.05) 7.7 (3.6 - 10.9) 

Copper (Cu) (μg/g) 30.1 (17.6 - 45.1) 38.8 (35.3 - 42.6) 31.7 (23 - 45) 

Iron (Fe) (%) 4.0 (2.7 - 5.4) 4.9 (4.5 - 5.3) 3.4 (2,6 - 4,7) 

Potassium (K) (%) 1.3 (0.6 - 1.1) 2.0 (1.3 - 2.2) 1.6 (1.3 - 2.5) 

Magnesium (Mg) (%) 0.6 (0.5 - 1.1) 1.2 (0.8 - 1.4) 1.0 (0.7 - 13) 

Nickel (Ni) (μg/g) 44.0 (28.6 - 63.8) 63.3 (52 - 81) 52.0 (27 - 76) 

Lead (Pb) (μg/g) 14.2 (5.0 - 24.6) 21.8 (18 - 36) 14.3 (4.0 - 27) 

Zinc (Zn) (μg/g) 133 (81 - 264) 129 (116 - 147) 136 (109 - 214) 

Particulate organic 

carbon (POC) (%) 4.5 (1.6 - 7.8) 2.2 (1.7 - 3.3) 1.6 (0.7 - 3.0 
40 

Figure 3-3. Concentrations of iron (Fe) versus aluminum (Al) for suspended sediments from the 

Sagavanirktok (circles), Kuparuk (diamonds) and Colville (triangles) Rivers during 

May-June 2004 and 2006. Solid line is from a linear regression for sediment data from 

the ANIMIDA study area and dashed lines show 99% prediction interval for sediment 

data. From Trefry et al. (2009). 

Figure 3-4. Concentration of barium (Ba) versus aluminum (Al) for suspended sediments from 

the Sagavanirktok (circles), Kuparuk (diamonds), and Colville (triangles) Rivers 

during May-June 2004 and 2006. Solid lines are from linear regressions for sediment 

data from the ANIMIDA study area and dashed lines show 99% prediction intervals 

for sediment data. From Trefry et al. (2009). 

Concentrations of POC (as a % of TSS) varied by factors of 2 to 5 in each of the rivers between 

2001 and 2006, with the highest POC concentrations in Kuparuk River suspended sediments 

(Table 3-2). 

 

Al (%)

0 2 4 6 8 10

Fe (%)

0

2

4

6

8

Sagavanirktok 2004,06

Kuparuk 2004,06

Colville 2006

y = 0.49x + 0.18

r = 0.94, n = 196

Linear regression line and 99% prediction

 interval based on 1999-2002 data

Al (%)

0 2 4 6 8 10

Ba (μg/g)

0

300

600

900

1200

Sagavanirktok 2004,06

Kuparuk 2004,06

Colville 2006

Y = 72.9X +115

r = 0.82, n = 192

Linear regression line and 99% prediction

 interval based on 1999-2002 data

(a)
41 

3.1.1.3 96BDissolved Metals and Organic Carbon in River Water 

Concentrations of dissolved trace metals, defined as metals that pass a 0.4-μm polycarbonate 

membrane filter, in North Slope rivers can be quite variable during the spring floods and often 

reach maximum concentrations during peak flow (Rember and Trefry, 2004; Trefry et al., 

2004b). This trend for maximum concentrations of dissolved trace metals during peak flow in 

spring is influenced by the discharge of soil interstitial water and shallow surface water that is 

diluted by snow melt and flushed from surrounding soils into the rivers. During the short 

summers, the arctic coastal plain is covered with pools of standing water and lakes, into which 

trace metals are leached from soils. The permafrost and a relatively flat topography on the 

coastal plain inhibit lateral water flow during the summer months, extending the residence time 

of the surface water in the system. After the long frozen winter (8 to 9 months), increased surface 

runoff in the spring provides a direct pathway for the release of accumulated and freshly leached 

metals into the rivers from the thawing ponds and soils. 

Mean and range of concentrations of dissolved metals in the Kuparuk, Sagavanirktok and 

Colville Rivers during May-June 2001, 2002, 2004 and 2006, are summarized in Table 3-3. The 

mean dissolved Fe concentrations were 3.5 and 4.4 times higher in water collected in May-June 

from the Kuparuk and Colville Rivers, respectively, than in water collected at the same times 

from the Sagavanirktok River. The maximum concentrations of dissolved Fe and other metals 

occurred in all three rivers near the time of peak flow. The higher concentrations of dissolved Fe 

in Kuparuk and Colville River water may be related to higher concentrations of dissolved 

organic carbon (DOC) and lower pH in these waters than in Sagavanirktok River water. The high 

DOC concentration and lower pH tend to enhance leaching and transport of dissolved Fe and 

other metals. 

Concentrations of most other dissolved metals also were highly variable and were highest near 

the times of peak flow. However, concentrations of dissolved Ba and Ca did not vary much 

during spring in Sagavanirktok and Colville River water, but were highly variable in Kuparuk 

River water (Table 3-3). The concentration of dissolved Ca was higher in Sagavanirktok River 

water than in water from the other two rivers, reflecting the high concentration of calcite in 

suspended sediments (Table 3-2). Concentrations of dissolved As, Cu, Mn, and Zn also were 

highly variable in Kuparuk River water, possibly reflecting changes in redox potential in the 

waterlogged tundra sediments draining into this river. 

Concentrations of DOC were measured in water from the Sagavanirktok, Kuparuk, and Colville 

Rivers during peak and off-peak flow in June 2001 (Rember and Trefry, 2004; Trefry et al., 

2004b). Mean DOC concentrations during peak flow ranged from 5.0 mg/L in the Sagavanirktok 

River to 14.0 mg/L in the Kuparuk River (Table 3-3). These DOC concentrations were higher 

than those in river water during off-peak flow. DOC tends to complex with dissolved metals and 

hydrocarbons, increasing their apparent solubility. 

 
42 

Table 3-3. Mean and range of concentrations of dissolved (passing a 0.45 μm filter) metals in 

water collected in the Kuparuk and Sagavanirktok Rivers in the spring (May-June) of 

2001-2, 2004, and 2006 and in the Colville River in the spring of 2001 and 2006. 

Concentrations of dissolved organic carbon (DOC) in river water samples collected in 

June 2001 are included (ANIMIDA task 7: Trefry et al., 2004). Concentrations are μg/L 

(parts per billion) or mg/L (parts per million). From Trefry et al. (2009). 

Metal Kuparuk R. (2001-2, 

2004, 2006) 

Colville R. (2001, 

2006) 

Sagavanirktok R. 

(2001-2, 2004, 2006) 

Arsenic (As) (μg/L) 0.065 (0.041 - 0.153) 0.14 (0.12 - 0.16) 0.068 (0..05 - 0.11) 

Barium (Ba) (μg/L) 20.1 (3.5 - 79.3) 50 (46 - 54) 26.4 (16.1 - 35.1) 

Calcium (Ca) (mg/L) 11.2 (3.4 - 41.6) 9.3 (5.7 - 11.9) 27.8 (20.3 - 37.0) 

Cadmium (Cd) (μg/L) 0.011 (0.003 - 0.038) 0.008 (0.007 - 0.010) 0.015 (0.006 - 0.062) 

Chromium (Cr) (μg/L) 0.10 (0.08 - 0.15) 0.12 (0.11 - 0.12) 0.122 (0.08 - 0.206) 

Copper (Cu) (μg/L) 0.46 (0.05 - 0.99) 2.1 (1.5 - 2.7) 0.55 (0.06 - 1.6) 

Iron (Fe) (μg/L) 120 (17 - 259) 148 (60 - 282) 34 (1.0 - 7.2) 

Magnesium (Mg) (mg/L) 1.3 (0.5 - 3.9) 2.6 (1.8 - 3.6) 3.6 (1.0 - 7.2) 

Manganese (Mn) (μg/L) 18 (0.5 - 94) 22 (8 - 53) 10 (1.3 - 20.2) 

Nickel (Ni) (μg/L) 0.7 (0.1 - 1.2) 1.6 (1.2 - 2.3) 0.72 (0.33 - 1.27) 

Lead (Pb) (μg/L) 0.032 (0.003 - 0.066) 0.060 (0.039) 0.020 (0.006 - 0.040) 

Zinc (Zn) (μg/L) 0.45 (0.11 - 2.37) 0.29 (0.12 - 0.47) 0.42 (0.03 - 3.6) 

Dissolved organic carbon 

(DOC) (mg/L) 14 (12.6 - 15.8) 10.0 (8.0 - 13.2) 5.0 (2.0 - 8.9) 

3.1.2 53BPartitioning of Metals between Dissolved and Particulate Phases in River Water 

and Beaufort Sea Water 

An understanding of the chemical forms of metals in river water and coastal seawater is essential 

for understanding chemical reactions and bioaccumulation of the metals. Dissolved metals are 

more reactive and bioavailable than solid metals. Therefore, the kinetics of dissolution and 

precipitation of metals in waters of different hardness and salinity has a strong influence on the 

bioaccumulation and toxicity of the metals to aquatic plants and animals (Neff, 2002a). 

A simple distribution coefficient (Kd) has been used to provide one perspective on metal 

partitioning between dissolved and particulate phases, and resulting bioavailability to marine 

organisms (Neff, 2008). Therefore, a Kd can be used to model the behavior of dissolved and 

particulate Ba during the spring flood of river water. Distribution coefficients were calculated in 

this study as: 

 (concentration of particulate metal in μg metal/g particles) 

Kd = _________________________________________________________________________ . 

(concentration of dissolved metal in μg metal/g water) 

Despite significant differences in concentrations of dissolved and particulate Ba (Tables 3-2 and 

3-3) among the three North Slope rivers, the Kd values calculated for Ba were statistically equal 
43 

(t-test, α = 0.05). These results suggest that partitioning of Ba between dissolved and particulate 

phases is a quasi-equilibrium controlled process between free Ba2+ and suspended particles. 

Considering the large variations in water discharge, TSS, and concentrations of organic carbon, 

the apparent uniformity of the distribution coefficients for Ba indicates that discharge of TSS and 

organic carbon have little impact on the partitioning of Ba between dissolved and particulate 

phases. Each of the other metals has similar Kd values in spring flood waters from the three 

rivers (Table 3-4). 

Table 3-4. Mean and standard deviation distribution coefficients (Kd) for metals in spring flood 

water from the Sagavanirktok, Kuparuk, and Colville Rivers. Kd is the ratio of the 

concentration of particulate metal in water (μg metal/g particles) to the concentration of 

the dissolved metal in water (μg metal/g water). From Trefry et al. (2009). 

Metal Sagavanirktok River Kuparuk River Colville River 

2004 2006 2004 2006 2006 

Arsenic (As) 5.20 ± 0.20 5.11 ± 0.11 4.99 4.91 ± 0.21 4.89 ± 0.10 

Barium (Ba) 4.55 ± 0.04 4.36 ± 0.08 5.01 ± 0.10 4.44 ± 0.19 4.29 ± 0.01 

Calcium (Ca) 3.53 ± 0.05 3.33 ± 0.33 3.25 ± 0.09 2.96 ± 0.11 2.95 ± 0.03 

Cadmium (Cd) 4.58 ± 0.12 4.68 ± 0.15 4.48 ± 0.15 4.85 ± 0.24 4.70 ± 0.11 

Chromium (Cr) 5.89 ± 0.11 5.78 ± 0.13 5.90 5.80 ± 0.15 5.88 ± 0.04 

Copper (Cu) 4.82 ± 0.18 4.62 ± 0.20 5.32 ±0.35 4.70 ± 0.13 4.25 ± 0.06 

Iron (Fe) 5.99 ± 0.24 5.61 ± 1.15 5.50 ± 0.10 5.45 ± 0.18 5.47 ± 0.06 

Potassium (K) 4.64 ± 0.11 4.32 ± 0.35 4.43 ± 0.08 4.16 ± 0.12 4.24 

Magnesium (Mg) 3.52 ± 0.08 3.37 ± 0.34 4.04 ± 0.10 3.75 ± 0.21 3.75 ± 0.02 

Manganese (Mn) 4.78 ± 0.11 4.75 ± 0.17 4.54 ± 0.08 4.63 ± 0.41 5.05 ± 0.04 

Nickel (Ni) 5.04 ± 0.08 4.98 ± 0.10 5.37 ± 0.22 4.94 ± 0.07 4.68 ± 0.03 

Lead (Pb) 5.99 ± 0.22 5.71 ± 0.17 5.81 ± 0.34 5.68 ± 0.19 5.70 ± 0.04 

Zinc (Zn) 5.71 ± 0.10 5/32 ± 0.29 5.61 ± 0.23 5.33 ± 0.24 5.55 ± 0.15 

Metal Kd values provide a useful tool for predicting the bioavailability of metals in suspended 

sediments and surficial bottom sediments. Metals with high Kd values will be present almost 

exclusively in the low-bioavailability solid phase, whereas, a potentially significant fraction of 

metals with low Kd values may be in bioavailable, potentially toxic forms. By this metric, only 

the alkaline earths, Ca and Mg, both essential micronutrients, are likely to be highly bioavailable 

to freshwater and marine animals (Table 3-4). 

The use of a Kd is more complicated in rivers and seawater when concentrations of DOC change. 

For example, increased concentrations of dissolved Cu, Pb, and Zn in rivers during peak 

discharge occur despite relatively constant concentrations of particulate metals. These results 

suggest that a Kd is less likely to explain dissolved concentrations of these metals. During peak 

discharge, Kd values (x 104

) for Cu (4.4), Pb (116) and Zn (67) were 40 to 50% lower than 

during off-peak discharge in the Sagavanirktok River. In contrast, concentrations of DOC were 

~40% greater during peak discharge. Strong correlations between dissolved metals and DOC 

suggest that elevated concentrations of organic ligands during peak discharge alter partitioning of 
44 

Cu, Pb and Zn between dissolved and particulate phases. Thus, Kd values, are potentially more 

useful in low or more uniform DOC riverine environments. Results from previous studies in 

rivers have shown that distribution coefficients for Cu, Pb and Zn often have order-of-magnitude 

differences where a large fraction of the variance can be explained by concentrations of DOC 

(Shafer et al., 1999). 

3.1.3 54BDispersion of River Water, Suspended Sediments, and Chemicals Under the Ice 

in the Beaufort Sea 

The high water flow from rivers during the spring floods is carried to a Beaufort Sea that is 

covered with ~2-m thick, land-fast ice. Thus, the river water flows out above and below the ice. 

The fresh and relatively warm (slightly >0 C) discharge from the rivers flows out onto and then 

under the land-fast ice where it mixes with the colder marine waters (-1.8° C) forming a 1-2 m 

thick under-ice lens of brackish waters that can extend >15 km offshore. This under-ice mixing 

takes place in the absence of wind and wave effects and sets the stage for the estuarine 

conditions and stratification that dominate nearshore regions during the early to mid open-water 

time period. Furthermore, river water that is not advected off the shelf can retain its distinct 

geochemical signature and move with the local circulation (Granskog et al., 2005). 

The main objectives of components of cANIMIDA Task 3 & 4 were to track the under-ice river 

water during the spring melt and to identify general flow patterns and behavior of freshwater, 

dissolved and particulate chemicals, and potential contaminants from the Sagavanirktok and 

Kuparuk Rivers. This information can be used to help predict dispersion patterns for freshwater, 

suspended sediments, dissolved chemicals and potential contaminants originating from activities 

on the North Slope of Alaska. The under-ice movement of freshwater plumes is an important 

component of potential spill trajectories as well as biogeochemical models during the period of 

maximum river discharge when these plumes provide a means for offshore transport of potential 

contaminants. 

During the breakup of the Kuparuk and Sagavanirktok Rivers in 2004, river water initially 

flowed out over the bottom-fast ice before encountering ice cracks, seal holes, and other breaks 

in the ice surface that allowed most of the river water to make its way through and under the ice 

canopy. Typically, over-ice flow extended 5 to 10 km from the river mouths and would 

sometimes recede after finding passages down through the ice, whereas the under-ice plume of 

mixed river water was transported up to 15 to 20 km offshore before encountering offshore 

barrier islands or the shear zone. At least 50% of the total flow of the Sagavanirktok River during 

the study period could be accounted for as being under ice within the somewhat limited area that 

was sampled. 

3.1.3.1 97BDispersion of River Water under Ice in the Beaufort Sea During Spring 2004 

River water flow began in both rivers on May 20, 2004. River water, seawater, and ice cores 

were collected from May 23 to June 2, 2004 during the landfast ice period while rivers were at 

high flow. River water was sampled daily and seawater was collected over a nine-day period 

through holes drilled in the ice at 28 stations (Figure 2-2). Vertical profiles of salinity, 

temperature and turbidity also were obtained at each location. Sampling through the ice was 

limited to nine days by the time of onset of the floods, weather conditions, and accessibility 

when nearshore areas flooded above the ice. 
45 

Objectives of the under-ice study were to trace the dispersion of freshwater to track the mixing 

and movement of suspended sediments and dissolved chemicals. Representative salinity and 

temperature profiles for the Kuparuk River transect stations K1, K3 and K4 (see map in 

Figure 2-2) show the sharp vertical pycnocline due to the flow of river water under the ice and 

above seawater (Figure 3-5). The profiles also show increasing salinity in the surface water with 

distance offshore. No detectable fraction of river water was detected at station K4, the station 

farthest offshore, even near the end of the sampling period on May 29. 

Figure 3-5. Vertical profiles for salinity and temperature for stations K1, K3 on May 23, 2004 

and station K4 on May 29, 2004, all located offshore of the mouth of the Kuparuk 

River (See Figure 2-2 for station locations. From Trefry et al. (2009). 

There was a similar rapid shift in salinity off the Sagavanirktok River. Over just six days, the 

salinity in the surface water decreased from ~18 to 5‰ and the thickness of the pycnocline 

increased by ~2 m. In 2004, strong haloclines and thermoclines were observed near the mouth of 

the Sagavanirktok River at Stations SE0 and SE1 (Figure 3-6). River water mixed along a frontal 

zone as the under-ice plume extended offshore to stations SE2 and SE3. Turbidity in the underice river plume decreased with distance from the river mouth as shown in Figure 3-6 for the 

Salinity

0 5 10 15 20 25 30 35

Water Depth Under Ice (m)

0

2

4

6

8

10

Temperature (°C)

-2.0 -1.5 -1.0 -0.5 0.0

Temperature Salinity

Station K1

 

Salinity

0 5 10 15 20 25 30 35

Water Depth Under Ice (m)

0

2

4

6

8

10

Temperature (°C)

-2.0 -1.5 -1.0 -0.5 0.0

Temperature Salinity

Station K3

Salinity

0 5 10 15 20 25 30 35

Water Depth Under Ice (m)

0

2

4

6

8

10

12

Temperature (°C)

-2.0 -1.5 -1.0 -0.5 0.0

Station K4

Temperature Salinity
46 

Figure 3-6. Under-ice vertical profiles of temperature, salinity, and turbidity taken along the SE 

transect off the Sagavanirktok River, starting near the bottom-fast ice zone and 

extending offshore beyond the barrier islands just south of the offshore shear zone, 

1 June 2004. From Trefry et al. (2009). 

transect from nearshore station SE0 to offshore station SE3. This trend probably is caused by 

settling of suspended sediments from the water column. The influence of runoff from both the 

Kuparuk and Sagavanirktok Rivers extended >15 km from their respective mouths where the 

under-ice plume encountered the barrier islands and the shear zone offshore of Northstar and 

Cross Islands (see map in Figure 2-2). Horizontal contour maps of temperature, salinity and 

turbidity at a depth of 2 m (~0.5 m below the ice canopy) show the under-ice plume extending 

well offshore. In contrast, turbidity decreased from nearshore to offshore as suspended sediments 

settled from the water column. The under-ice plume associated with the Sagavanirktok River had 

much higher concentrations of suspended sediments than the Kuparuk River. 

Distinct differences in turbidity patterns at the mouths of the two rivers were observed due to the 

higher suspended sediment load of the Sagavanirktok River; however, the behavior of the TSS 

during mixing was non-conservative; therefore, turbidity was not useful for following the 

seaward progression of freshwater from the two rivers. Two additional variables, 18O and 

dissolved silica, did prove to be useful tracers for the two rivers and were used to determine the 

relative amounts of river water, seawater and sea ice melt at each station. 

Three tracers, salinity, 18O, and dissolved silica, provided distinct geochemical fingerprints that 

were used to calculate the relative contributions of four water masses, Sagavanirktok River (SR), 

Kuparuk River (KR), sea ice melt (SIM) and polar mixed layer (PML), to individual water 

samples and to trace the under-ice dispersion of freshwater. Some background perspective on use 

of 18O and silica as tracers is provided below. 

The 18O of water (e.g., 1

H1H18O versus 1H1H16O) is zero for standard mean ocean water 

(SMOW) where 

18O = (U

18O/16O)sample – (18O/16O)standard U

 x 1000 ( 18O/16O)standard
47 

 and SMOW is the standard. The 18O of freshwater in rivers becomes more negative (richer in 

16O relative to the standard) at higher latitudes due to a process called Rayleigh distillation 

whereby cycles of evaporation and rainfall north of the equator favor the transport of the lighter 

isotope (16O) away from the equator. Thus, the SR and the KR had 18O values of -21.7 and – 

23.0, respectively, relative to -3.4 in Beaufort Sea water (PML) and -0.8 in SIM. These 

differences allow 18O to be used as a second tracer, one that is independent of salinity. 

The strong linear relationship between salinity and 18O, coupled with marked differences in 

end-member values for each parameter, yielded two variables that facilitated discrimination 

between river water and seawater. However, the data for salinity and 18O could not be used to 

effectively differentiate SR from KR water. Despite daily variations in the concentrations of 

dissolved silica for the SR, silica could be used to distinguish between water from the SR and 

KR because the endmember values for each river were significantly different. Concentrations of 

dissolved silica in the SIM also were distinct and helped to better define the contribution from 

sea-ice melt. Water at some SK stations contained a mixture of SR and KR water. Data points for 

some of the SW stations plotted below the SR-PML mixing line due to variations in the silica 

endmember for the SR. Dissolved silica was essentially conservative in the study area because 

the seasonal landfast ice cover restricted growth of phytoplankton, thereby greatly reducing the 

amount of biological uptake in the surface water (Granskog et al., 2005; Weingartner and 

Okkonen, 2001). 

The fraction of SR water under ice in Stefansson Sound increased during the late May 2004 

flood period. On May 25, the top 1 m of the water column at stations SW1 to SW3 contained 61 

to 84% SR water. Three days later, there was an increase in the percent and depth of penetration 

of SR water along the SW transect. For example, the fraction of SR water increased from 10 to 

63% at 1.5 m for station SW2 and from 2 to 29% at 1 m for station SW4. The increased fractions 

of SR water along the SW transect showed both the seaward and vertical progression of the SR 

plume. 

The largest fractions of SR water (>90%) were found at depths of 0.5 to 1.5 m along the S1-S4 

transect on May 31. Samples in the top 1 m at station S4 contained >60% SR water, even though 

station S4 was 16.7 km offshore and was the most seaward station sampled (Figure 2-2). The 

higher fractions of SR water observed along the S transect were partly due to the May 31 sample 

date. However, station SW4 was re-sampled on May 31 when it had a SR water fraction of 62% 

at 1 m depth. This fraction was similar to values of 73% and 62% (on May 31) at stations S3 and 

S4 that were located ~2.7 and 5.6 km farther north, respectively. Therefore, regardless of time, 

the SR plume progressed predominately along the S transect, as discussed in more detail below. 

East of the S transect, the SR plume extended ~6.3 km seaward with >70% SR water in the top 1 

m of the water column at stations SE1 and SE2. However, no detectable SR water was found at 

stations SE3 and SE4. Collectively, the OMP results supported movement of the SR plume 

seaward primarily along the S transect and secondarily along the SW transect with some 

eastward movement along the SE transect closer to shore. 

A layer of water with a salinity of 25 to 30‰ was observed beneath the SR plume at ~2.5 m for 

all stations due to entrainment of denser waters below the pycnocline. As the plume shoaled and 

the water depth increased (moving offshore), this water layer widened below the plume and 

surfaced ahead of the front. The observed trend suggested mixing of SR water with another layer 
48 

of lower salinity water that was deeper (>1.5 m) in the water column at stations seaward of the 

SR plume. This additional source of lower salinity water was attributed to inputs of sea-ice melt 

(SIM) that was pulled downward beneath the seaward-moving plume front via convergence due 

to a shoreward flow at depth. The percent of SIM was generally <20% throughout the study area, 

with larger fractions present at stations farther offshore due to greater melting in the vicinity of 

offshore barrier islands. However, at some nearshore stations (SW1, S1, SE1, and SE2), >10% of 

SIM was calculated for some water samples. These larger fractions of SIM nearshore may have 

formed by heat advected directly by the river water or indirectly via the increased absorption of 

solar radiation from turbid river water flowing above the ice canopy. 

The SR plume probably was a single, large structure that moved predominately northward along 

the S and SW transects and spread >15 km to the west and ~5 km to the east of the S transect 

(Figure 3-7). Turbulent mixing near the mouth of the SR created a well-mixed, fresher water 

column that advected seaward with increasing discharge to form a well-stratified flow beneath 

the ice farther offshore. The spread of the SR plume was limited by entrainment, lateral mixing, 

and buoyancy forcing. 

Figure 3-7. Quasi-synoptic view of the percent Sagavanirktok River (SR) water (top) and 

Kuparuk River (KR) water (bottom) at 1.0 m for May 27-31. Water mass fractions 

were rounded to the nearest 10%. From Trefry et al. (2009). 
49 

Results from the SK stations (SK2-SK10), sampled on May 29 and 30, show the movement of 

SR water westward as well as the interaction between SR and KR plumes as they converged 

beneath the ice. Flow from the KR that moved eastward toward the SK stations was channeled 

by barrier islands and man-made causeways just north of the river mouth that effectively redirected the plume alongshore. 

Approximately equal fractions of ~40-50% SR and KR water were found in the top 1 to 1.5 m of 

the water column at stations SK5 and SK7, where the two plumes met. The distribution of the 

water mass fractions suggest a northward flow of plume water as a result of convergence at or 

shoreward of station SK5 between the SR plume moving west and the KR plume moving east. 

For example, the eastward flow of the KR plume, with maximum fractions of KR at stations SK8 

and SK10, was driven upward to ~1 m depth by increased mixing with SR water that was 

moving westward and downward from SK2 and SK4. As the two plumes converged, a northward 

flow may have been generated and guided by the shallower bottom topography to the east. As a 

result, the KR plume appears to have forced the westward flowing SR water to the north and 

increased the offshore movement of freshwater. 

No SR water was identified at station SK8 and <20% SR water was found at station SK10. Thus, 

the SR plume did not flow farther west than station SK5, but was advected north to stations SK6 

and SK7. In contrast, KR water was abundant to >2 m depth at stations SK8 to SK10 as a result 

of further re-direction northward by the causeway connecting Point McIntyre and the STP to 

shore (Figure 2-2) as well as the westward moving SR plume. As a result of mixing between the 

two plumes along the SK5, SK6, and SK7 transect (meridional), more SR water was advected 

along the 1.5 m isobath as the SR and KR plumes merged and mixed in the top 1 m of the water 

column. Furthermore, the decrease in the fraction of KR water east of stations SK8, SK9, and 

SK10 showed the seaward deflection of the plume due to interaction with the SR water. The KR 

plume was mixed more easily by turbulence with the oppositely-flowing local circulation. 

However, the presence of the KR plume was sufficient to force westward-spreading SR water 

north, increasing the possibility of advection to the outer continental shelf. Such interaction 

among the many rivers along the northern coast of Alaska may aid in the transport of freshwater 

off the shelf between barrier islands via convergence of alongshore flows (Weingartner et al., 

1999; 2009) and steering by bottom topography (Carmack et al., 1997; Weingartner et al., 2009). 

Currents under the ice averaged 7.2  3.2 cm/sec at 309  76 compass direction (n = 40). The 

current data were categorized as surface (1 and 1.5 m) and sub-surface (>2.5 m) based on the 

observed 1-1.5 m thickness of the SR plume. Surface currents, with an average magnitude of 6 

3 cm/sec at 313  115 (n = 17) were not significantly different from sub-surface currents that 

averaged 8  3 cm/sec at 303  34 (n = 23). These results suggest that a landward flow present 

in the top layer of the water column under ice prior to the spring floods reversed during high 

river discharge. Water flow in Stefansson Sound was northwestward and parallel to the shoreline 

for the entire study period. Exceptions to this trend occurred only where there were mixing 

fronts, changes in bathymetry, or barrier islands. Maximum current velocities of >10 cm/sec in 

this study usually were found in regions of plume fronts. 

Weak relationships (r2 <0.33) were observed among alongshore and cross-shore current 

magnitudes, changes in sea level height, and stage height. Thus, local circulation was most likely 

forced by the baroclinic pressure/density gradient set up by the initial high discharge of river 
50 

water over the saline shelf water. We also observed that the northwestward flow of the local 

circulation contradicts the usual eastward deflection of northward moving waters due to the 

Coriolis force. This resultant flow was most likely due to the influence of the high intensity of 

the river runoff as well as possible forcing from the larger scale anti-cyclonic Beaufort Gyre 

offshore (Weingartner and Okkonen, 2001). 

Mixing gradients were calculated using the fractions of SR water along isobaths between 

stations. These gradients helped to quantitatively support qualitative inferences of SR water 

movement based on the distributions of water mass fractions. Calculations were carried out for 

the top 1.5 m of the water column where differences in the SR water mass fractions between 

stations were >10 %. Gradients were calculated in % km -1 as follows: 

 Gradient (z) = ([% River]2 – [% River]1) / L 

where flow was assumed to be from station 1 to station 2 (subscripts 1 and 2) along a given 

sampling depth (z = 0.5, 1, or 1.5 m) and L = distance (in kilometers) between stations. The 

calculation yielded negative gradients along an assumed flow pathway and positive gradients 

when opposite the proposed flow. The following simplifying assumptions were applied to the 

gradient calculations: (1) a single source was selected for the SR water at what was believed to 

be the primary outflow and (2) gradient calculations assumed all river water entering the study 

area did so via only this outflow. 

Flow pathways were determined by comparing horizontal gradients and assumed that smaller 

gradients (<-5% km-1) represented primary flow pathways and larger gradients (>-10% km-1) 

represented a resistance to flow or shear that was identified where physical barriers or water 

mass fronts were present. For example, on May 25, two possible flow pathways of SR water to 

station SK1 along the 1 m isobath were chosen, one from the SR mouth (SR/L = -69%/10.5 km 

= -7% km-1) and the other from station SW2 (SR/L = -44%/3.3 km = -16% km-1). The two 

gradients suggested that SR water more likely flowed directly from the mouth of the SR because 

it would have been less mixed by approximately a factor of two along that route. 

The flow pathways determined by comparing horizontal gradients in this manner are shown 

schematically in Figure 3-8. Generally, mixing (larger gradients) was comparatively lower in a 

cross-shore (N-S) versus alongshore (E-W) direction, indicating a preferential seaward advection 

of SR water. The presence of relatively unmixed SR water (>90% SR) from the mouth of the SR 

to stations closest to the shore (e.g., SK1, SW1, S1, and SE1) indicated a large and increasing 

pool of SR water located shoreward of these stations. Mixing fronts were consistently observed 

between stations located farther offshore (e.g., SW4 and SW5) with magnitudes >20% km-1, 

marking the limits of the spread of SR water. Small mixing gradients (<4% km-1) observed 

between the SR mouth and the SK stations confirmed a large westward spread of SR water. 

A freshwater budget was calculated for the SR discharge based on water mass fractions. The 

total amount of SR water was calculated as water depth equivalents (in meters) for each station 

by summing the distribution of water mass fractions over the water column to a depth of 2.5 m 

(no river water was observed below this depth during the study). Water mass fractions were 

assumed to be evenly distributed between sampling depths. The top 0.5 m of the water column 

under ice was assumed to be homogeneous. 
51

Figure 3-8. Qualitative flow pathways for Sagavanirktok River (SR) water according to lowest 

negative gradients and the calculated area of influence of the SR plume (rectangle). 

Solid triangles show the locations of the SR and Kuparuk River (KR) outflows in 

gradient calculations. The lengths of arrows show the distance over which the SR 

plume was observed. From Trefry et al. (2009).

Data from stations that were re-occupied during the study were used to estimate the rate of 

change in SR water for the entire sampling area. These rates were then utilized to estimate the 

total SR water at each station at the end of the study (June 2), and thereby obtain the discharged 

water depth equivalent for the study area (Figure 3-7). Some values were adjusted so that the 

depth equivalent of SR water was <2.5 m, and data for stations SK1 and SK2 were adjusted so 

that values did not exceed their total bottom depths of 1.5 and 1.0 m, respectively.

The comprehensive sum of SR water in the study area was 34.7 m, ~14 % of which flowed east 

to stations SE1 and SE2, ~35% flowed west to the SK stations, and ~50% flowed north to the 

SW (28%) and S (22%) stations. Overall, ~65% of the SR discharge identified during this study 

was found east of Prudhoe Bay. These observations supported the primary movement of SR 

water northward along the S transect with an influence from both the local circulation and KR 

plume (Figure 3-8).
52 

The depth equivalent of SR water at individual stations was averaged to obtain a value of 1.6 

0.7 m. This average value was multiplied by the relative area of SR plume influence (~315 km2), 

to yield a total volume in the study area on June 2, 2004 of 0.5  0.2 km3. Based on the USGS 

data, the measured total SR flow during our study period was ~1 km3 (includes 5X multiplier 

from Rember and Trefry (2004) that was based on a determination that the U.S.G.S. gauge 

accounts for only ~20% of the total SR flow). Therefore, on June 2, 2004, the calculated 0.5 km3

of SR water that was under the ice at the mouth of the SR in the coastal Beaufort Sea accounted 

for only ~50% of the total discharge. The discrepancy between the two values for flow was most 

likely due to several factors including the following: movement of water away from our 

sampling area in the Beaufort Sea, open water closer to shore that was not included in the 

calculation, possible errors in gauge measurements at flood stages, use of the 5X multiplier, and 

water that was above ice during our sampling period. Any above-ice water will eventually reenter the water column via strudel holes or during the sea ice melt and consequent break-up in 

July. 

3.1.3.2 98BDispersion of Sediments and Metals Under Ice in the Beaufort Sea during Spring 

2004 

Sediments. Concentrations of TSS did not follow a simple mixing trend versus salinity and some 

of the particles settled out of the surface layer of the incoming fresh water (Figure 3-9). All data 

points, excluding one data point from the mixing zone, plotted below a simple mixing line 

between the seawater end-member of ~1 mg/L and the lowest value for TSS in the river of 43 

mg/L. Thus, concentrations of TSS in offshore samples are 15 to 90% lower than predicted from 

the smallest simple mixing gradient for particles along the pathway of the Sagavanirktok River 

plume. A similar trend was observed for the Kuparuk River. Concentrations of TSS along the 

mixing zone in the Kuparuk River decreased sharply and showed settling of >50% of the 

suspended sediments. Concentrations of TSS in samples off both rivers with salinities >30 

averaged 1 mg/L and ranged from 0.1 to 4 mg/L. 

Vertical profiles also are available for in situ turbidity. At station SW4, the first vertical profile 

for turbidity (May 25) shows a thin layer of suspended sediments at the surface with a gradual 

decrease across the pycnocline (Figure 3-10). After three days (from May 25 to May 28), the 

layer of suspended sediment thickened as the layer of fresh water thickened. No significant 

changes in turbidity occurred after an additional three days (May 31). However, when turbidity 

was viewed as a function of salinity for station SW4, the turbidity on May 31 was about half of 

the turbidity on May 28 for the same salinity. This trend is most likely related to a combination 

of mixing and thickening of the plume and continued settling of particles from the under-ice 

plume, as well as increased flocculation of clay particles with decreasing salinity. 

Some links between river inputs of suspended sediments and local offshore sedimentation rates 

can be made with available data from the cANIMIDA Project. Our previous results showed that 

sedimentation rates ranged from ~0.04 cm/yr to ~0.10 cm/yr with several sites having little or no 

net accumulation of sediment during at least the past 50 years (Trefry et al., 2003). At two sites, 

we identified 3 to 5 cm thick layers of sediment that were deposited since development on the 

North Slope began during the 1960s. Our overall results are consistent with those of Naidu et al. 
53 

Figure 3-9. Total suspended solids (TSS) versus salinity (a) full-scale for TSS and (b) TSS at 0 

to 50 mg/L for the Sagavanirktok River and offshore in Stefansson Sound during MayJune 2004. Dashed line on (a) shows simple mixing line between TSS of average river 

water (127 mg/L) and seawater (1 mg/L). Solid line on (a) and (b) shows simple 

mixing line between lowest value for TSS in river water during peak flow (43 mg/L) 

and a value of 1 mg/L for seawater. From Trefry et al. (2009). 

(2001) for the same area, namely that sedimentation rates and isotope activities are very low. We 

also know from our previous work that the presence of fine-grained sediment at a given location 

can vary from year to year and that the sediment movement along much of the shallow, coastal 

Beaufort Sea is quite dynamic. 

Salinity

0 5 10 15 20 25 30 35

TSS (mg/L)

50

100

150

200

250

300

Sag. River

SW Transect 

S Transect 

SE Transect 

(a)

Salinity

0 5 10 15 20 25 30 35

TSS (mg/L)

0

10

20

30

40

50

Sag. River

SW Transect 

S Transect 

SE Transect 

May 27

May 27

May 27

May 31

May 28

May 27

May 27

May 28

May 31

May 25

May 31

May 31 May 31

May 25

May 25

May 25

(b)
54 

Figure 3-10. Vertical profiles of turbidity at station SW4 on May 25, May 28 and May 31, 2004. 

From Trefry et al. (2009). 

The low sedimentation rates at stations in Prudhoe Bay and near the Endicott development can 

be supported by comparison with data for river inputs of suspended sediments. For example, the 

Sagavanirktok River, the major river source of sediments to this area, is estimated to have an 

annual sediment load of about 6 x 105

 metric tons (Rember and Trefry, 2004). The depositional 

area for this sediment in the coastal Beaufort Sea is about 1000 km2,

 yielding an estimated 

deposition rate of ~0.04 cm/y, based on a sediment bulk density of 1.6 g/cm3

 ([0.6 x 1012 g dry 

sediment/10 x 1012 cm

2

] x [(1.6 g wet sediment/cm3)/(2.6 g dry sediment/cm3)]). This calculated 

value is consistent with results from direct determinations of sedimentation rate. 

Metals. Concentrations of dissolved and particulate metals were traced under ice across the 

freshwater-seawater mixing zones in a manner similar to that described previously for salinity, 

dissolved silica, δ18O and suspended sediments. The data are used here as follows: (1) to describe 

how the mixing process influences concentrations of dissolved and particulate metals and (2) to 

obtain a better perspective about concentrations of metals in suspended sediments relative to 

bottom sediments. Concentrations of dissolved and particulate metals may provide a useful and 

more sensitive short-term (days to months) integrator of any future metal contamination than 

bottom sediments (Trefry et al., 2003). Concentrations of dissolved and particulate metals also 

provide an important link with biological uptake of potentially toxic metals. However, the 

complexities of natural trends for dissolved and particulate metals must be well understood in 

order to use them as tracers of contamination and bioaccumulation in the ecosystem. The metals 

chosen for study in this project represent a combination of metals selected by MMS and us 

because of their usefulness as tracers of potential contamination in the study area and their 

presence in drilling/production wastes. 

 Concentrations of dissolved As followed a strong positive trend versus salinity across the 

freshwater-seawater mixing zone, even when data for both the Sagavanirktok and Kuparuk 

Rivers were combined on the same graph (Figure 3-11). Concentrations of dissolved As in both 

the Sagavanirktok (0.068 ± 0.015 μg/L) and Kuparuk (0.041 μg/L) rivers were low relative to 

Turbidity (NTU)

0 5 10 15 20

Water Depth (m)

0

2

4

6

8

SW4-1 May 25

SW4-2 May 28

SW4-3 May 31
55 

Figure 3-11. Concentrations of dissolved As versus salinity for water samples collected under 

ice across the mixing zones from the Sagavanirktok and Kuparuk Rivers to the coastal 

Beaufort Sea. Shaded area was drawn to emphasize the range of dissolved As 

concentrations in the polar mixed layer. Line and equation are from a linear 

regression. Dashed lines show 95% prediction interval. From Trefry et al. (2009). 

seawater values of 1.0 ± 0.1 μg/L. The observed trend supports simple mixing of dissolved As 

under the ice with no easily detectable biological or physical removal or addition of dissolved As 

over the one to two week study period. The large range of dissolved As concentrations at a 

salinity of 32 (the polar mixed layer) was most likely the effect of long-term (many months) 

biological and chemical processes. The data in Figure 3-11 also support the hypothesis that the 

primary source of dissolved As to the coastal water of the cANIMIDA study area was from 

upwelling of deeper, offshore water with advection into Stefansson Sound, not from river runoff. 

When the data for As in suspended matter collected under ice were plotted versus particulate Al, 

>80% of the data points plotted within the 99% prediction interval developed using sediment 

data from the coastal Beaufort Sea (Trefry et al., 2003). However, 10 data points for samples 

from the K Transect and two from the SW Transect plotted above the upper confidence interval. 

Each of these samples of suspended matter contained a lower Al content (at 1-5% Al) relative to 

river particles, suggesting that they contained more As-rich organic matter (Trefry et al., 

2004a,b). 

Based on the absolute amount of As per liter of sample, river water contained >90% particulate 

As whereas seawater (the polar mixed layer at a salinity of 32) contained <5% particulate As. 

Along the freshwater-seawater mixing gradient (with linearly increasing concentrations of 

dissolved As), the decrease in concentrations of particulate As (in μg/L) was much sharper than 

the increase in concentrations of dissolved As. This trend of higher concentrations of dissolved 

As at higher salinity also supports upwelling of offshore waters, rather than desorption of As 

from river particles, as the primary source of dissolved As in Stefansson Sound. 

Salinity

0 5 10 15 20 25 30 35

Dissolved As (μg/L)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Sag

Kuparuk

K Transect

SK Transect

SW Transect

S Transect

SE Transect

Y = 0.032X + 0.030

 r = 0.98; n = 73 

May-June 2004 Under Ice
56 

The relationship of particulate Cu versus particulate Al concentrations is very similar to that 

observed for particulate As versus particulate Al with some higher concentrations of Cu at lower 

concentrations of Al. The observed Cu enrichment is for the same samples of suspended matter 

that were enriched with As. In addition to the Cu-rich samples, samples from the SW and S 

transects are Cu-poor relative to Al (plot below the lower prediction interval based on typical 

regional sediments). Such a decrease in particulate Cu concentrations and the Cu/Al ratio could 

be due to desorption of Cu across the freshwater-seawater mixing zone as described for other 

rivers for Ba and Cd (Hanor and Chan, 1977) or addition of some more Al-rich (or Cu-poor) 

suspended matter in the area of transects SW and S. 

In contrast with As, concentrations of dissolved Cu in the Sagavanirktok River (0.5 ± 0.2 μg/L) 

are similar to those in offshore water samples (0.5 ± 0.2 μg/L) and both are slightly higher than 

concentrations of 0.2 ± 0.1 μg/L in the Kuparuk River. Thus, it is difficult to see any significant 

deviations from a conclusion of no change or simple dilution across the freshwater-seawater 

mixing zone for dissolved Cu. Any other trends for dissolved Cu concentration versus salinity 

seem to be masked by expected temporal variations in concentrations of Cu in the rivers during 

high flow. 

However when dissolved Cu concentrations for just the S and SE transects are regressed versus 

salinity, a relatively strong negative relationship is observed (river water data are excluded from 

linear regression). This trend suggests that Cu was not very reactive during mixing. Some high 

particulate Cu/Al ratios at a salinity of ~32, as well as at dissolved Cu concentrations of 0.3-0.4 

μg/L, support the possibility of biological Cu enrichment. 

Concentrations of particulate Fe were skewed to the high side of the Fe/Al ratio obtained for 

bottom sediments in the cANIMIDA area (Figure 3-12a). Data points that exceeded the upper 

prediction interval for Fe/Al in sediments were predominantly for suspended sediments from the 

Kuparuk River and adjacent K and SK Transects (Figure 3-12a). A trend of slightly higher 

particulate Fe concentrations, relative to Al, in the Kuparuk River was observed consistently 

during the ANIMIDA Project (Rember and Trefry, 2004; Trefry et al., 2004a,b). The Kuparuk 

River drains mainly arctic tundra and the river water contains higher concentrations of DOC and 

dissolved Fe (Rember and Trefry, 2004). The higher Fe/Al ratio in suspended sediments under 

the ice is consistent with previous observations. However, the impact of such particles on bottom 

sediments in the study area seems limited based on the narrow 99% prediction interval for Fe/Al 

in Figure 3-12a. This observation is consistent with a lower sediment load for the Kuparuk River 

and trapping of incoming particles by the Kuparuk delta and adjacent barrier islands. 

Very few deviations were observed for particulate Ba/Al in suspended sediments relative to 

trends predicted from bottom sediments (Figure 3-12b). This observation is consistent with 

previous data sets, as was the occasionally higher Ba/Al ratio for suspended sediments from the 

Kuparuk River. 

The regression of particulate Cr versus particulate Al concentration in water is similar to that for 

particulate Fe versus Al concentration in that some data points from the K and SK transects plot 

above the upper confidence interval based on the sediment data. However, the regression for 

particulate Cr versus particulate Al concentration from the Kuparuk River plotted on the lower 

half within the prediction interval rather than above the upper prediction interval as observed for 

Fe. When particulate Cr values were plotted versus concentrations of particulate Fe, most of the 
57 

Figure 3-12. Concentrations of particulate Fe (a) and Ba (b) versus particulate Al for samples 

from the Sagavanirktok and Kuparuk Rivers and the coastal Beaufort Sea. Solid lines 

are from a linear regression and dashed lines show 95% prediction intervals based on 

sediment data for the coastal Beaufort Sea. From Trefry et al. (2003, 2004). 

data for the K and SK transects plotted within the prediction interval for Cr/Fe in bottom 

sediments. however, the Kuparuk River samples and selected other samples plotted below the 

lower prediction interval. 

No discernible shifts in concentrations of dissolved Cr were observed across the freshwaterseawater mixing zone under ice. This indicates that Cr was not very reactive during mixing under 

Particulate Al (%)

0 2 4 6 8 10

Particulate Fe (%)

0

2

4

6

8

Sag 

Kuparuk

K Transect

SK Transect

SW Transect

S Transect

SE Transect

May-June 2004 Under Ice

Regression line and prediction

interval are based on sediment data. 

(a)

Al (%)

0 2 4 6 8 10 12

Ba (%)

0

200

400

600

800

1000

1200

Sag 

Kuparuk

K Transect

SK Transect

SW Transect

S Transect

SE Transect

Regression line and prediction

interval are based on sediment data. 

(b)

May-June 2004 Under Ice
58 

the ice. The low values for dissolved Cr in some low salinity samples from the SK transect may 

be related to lower concentrations of dissolved Cr in the Kuparuk River than shown by the single 

data point available for the river. 

Concentrations of particulate Cd follow the same trend previously described for As and Cu with 

high concentrations in samples with a lower Al content that were collected at higher salinity. In 

the case of Cd, the anomalously high concentrations of particulate Cd were 4 to 12 times greater 

than in typical Al-rich suspended or bottom sediments (Figure 3-13). Enrichment of Cd in 

sediments due to diagenetic processes (Gobeil et al., 1997) is not likely to have played a role in 

the observed Cd enrichment of suspended particles because the highest sediment Cd value that 

has been observed and linked to such processes in the cANIMIDA study area was 0.4 μg/g 

(Trefry et al., 2003). Data for plankton show that Cd concentrations were typically in the range 

of 1 to 10 μg/g, dry wt. Suspended matter from our study with 50% of the typical values for Al 

(i.e., 4% instead of 8%) contained Cd at about 2 μg/g (dry wt.) that would extrapolate to a 

reasonable value of 4μg/g at 0% Al (all plankton or organic matter). 

Figure 3-13. Concentrations of particulate Cd versus particulate Al for water samples from the 

Sagavanirktok and Kuparuk rivers and the coastal Beaufort Sea. Solid line is from a 

linear regression and dashed lines show 95% prediction intervals based on sediment 

data for the coastal Beaufort Sea from Trefry et al. (2003). From Trefry et al. (2009). 
59 

Concentrations of dissolved Cd increased from 0.016 ± 0.005 μg/L in the rivers to 0.067 ± 0.013 

μg/L in seawater samples with salinities of 32‰ (Figure 3-14). However, considerable scatter 

was observed in the regression of dissolved Cd concentration versus salinity, and the correlation 

coefficient was 0.73. River water contained 50-90% particulate Cd and seawater (at a salinity of 

32‰) contained<5% particulate Cd (Figure 3-15). Unlike the situation for As, concentrations of 

dissolved Cd along the freshwater-seawater mixing gradient may be influenced by desorption of 

Cd. However, as shown for As, the relationship between particulate and dissolved Cd seems to 

suggest that the main source of dissolved Cd in the study area is from upwelling from deeper, 

offshore water. 

Figure 3-14. Concentrations of dissolved Cd versus salinity for water samples collected under 

ice across the mixing zones from the Sagavanirktok and Kuparuk Rivers to the coastal 

Beaufort Sea. The solid line and equation are from a linear regression calculation, r is 

the correlation coefficient, and the dashed lines show the 95% prediction interval. 

From Trefry et al. (2009). 

Figure 3-15. Concentrations of particulate Cd versus dissolved Cd in water samples collected in 

the Sagavanirktok and Kuparuk Rivers and under ice in the coastal Beaufort Sea. 

From Trefry et al. (2009). 

Salinity

0 5 10 15 20 25 30 35

Dissolved Cd (μg/L)

0.00

0.04

0.08

0.12

0.16 Sag 

Kuparuk 

SK Transect

Salinity vs SK dCd 

SW Transect

S Transect

SE Transect

Y = 1.37X + 0.03

 r = 0.73

Dissolved Cd (μg/L)

0.00 0.04 0.08 0.12

Particulate Cd (μg/L)

0.000

0.005

0.010

0.050

0.100

0.150
60 

Concentrations of particulate Zn did not vary greatly from the predicted trend with Al because 

the concentrations of Zn in the suspended aluminosilicates were generally as high as or higher 

than found in plankton. In contrast, concentrations of As, Cu and Cd in plankton were much 

greater than found for aluminosilicates and thus the anomalies at low concentrations of Al 

reflected the higher levels of these three metals in plankton. 

The data for particulate Pb show a mix of trends previously discussed for Cr. Some high 

concentrations of particulate Pb were found at a variety of locations and some low concentrations 

were found in the Kuparuk River (Figure 3-16). 

Figure 3-16. Concentrations of particulate Pb versus particulate Al in water samples from the 

Sagavanirktok and Kuparuk Rivers and the coastal Beaufort Sea. 

From Trefry et al. (2009). 

3.1.3.3 9BDispersion of Water under Ice in the Beaufort Sea during Spring 2006 

Offshore sampling was carried out at 15 stations plus 5 moorings from May 22 through June 2, 

2006 (Figure 3-17). Sampling was focused along three transects, two from the Kuparuk River 

and one from the Sagavanirktok River, all of which were along the main flow path of the 

respective rivers as determined during the 2004 study. 

Vertical profiles of salinity, temperature, and turbidity in 2006 were similar to those seen during 

prior years (Figure 3-18). The first survey was conducted on May 22 prior to the breakup of the 

Sagavanirktok River, with subsequent surveys taking place during under-ice transport of river 

runoff. Vertical profiles of temperature and salinity from Station S2 show a sharp pycnocline 

during the May 24 and 26 surveys, with some vertical mixing taking place and a gradual 

thickening of the plume during the May 30 to June 3 surveys. The plume was about 2 m thick at 

the inshore locations and gradually mixed and thinned to less than 1 m further from shore 

(Figures 3-18 and 3-19). In the spring of 2006, the under-ice plume extended beyond the barrier 

islands (Reindeer and Cross Islands), but did not extend as far as the beginning of the shear zone 

which was located approximately 1 km beyond the barrier islands at the time of the survey. In 

Particulate Al (%)

0 2 4 6 8 10

Particulate Pb (μg/g)

0

10

20

30

40

Sag 

Kuparuk

K Transect

SK Transect

SW Transect

S Transect 

SE Transect

Regression line and prediction

interval are based on sediment data. 

May-June 2004 Under Ice
61 

2004, the plume extended to the edge of the shear zone which appeared to provide an underwater 

ice barrier to increased spreading of the plume in the offshore direction. 

 

Figure 3-17. Map showing sampling stations for the May-June 2006 under-ice study in the 

coastal Beaufort Sea. From Trefry et al. (2009). 

Figure 3-18: Vertical profiles of temperature, salinity, and turbidity taken at station S2 over a 

10-day period during May-June 2006. The accompanying map depicts the station 

location along with the location of the onshore-offshore transect for salinity. From 

Trefry et al. (2009). 

●

●

●

●

●

●

● ● ●

●

●

● ● ●

●

●

●

●

●

●

● ● ●

●

●

●

●

●

●

2004 Under Ice

28 stations

Kuparuk R.

Sagavanirktok R.

-149 -148.8 -148.6 -148.4 -148.2 -148 -147.8

70.3

70.35

70.4

70.45

70.5

Longitude

Latitude

SE1 

SE2 

SE3 

SE4 

S1

S2 

S3 

S4 

SW1 

SW2 

SW3 

SW4 

SW5

SK1 

SK2 

SK5 

SK8 SK3 

SK6 

SK9 SK4 

SK7 

SK10 

K1

K2 

K3 

K4 

K5 

Prudhoe Bay 

Sagavanirktok 

River 

Kuparuk River 

Stump 

Island 

Long Island 

STEFANSSON SOUND 

BEAUFORT SEA 

Gwydyr 

Bay 

N 

Pt. McIntyre 

STP 

Endicott 

3.8 km 

Spring 2006 

Under Ice

.K0

S4

S3/4

W11

.

.

.

. S3 .

Moorings

KW4

KW3

KW2

KW1

.

.

.

.

PBAY

KW6

.

Northstar
62 

Figure 3-19. Vertical contour map of salinity along an onshore-offshore transect extending from 

Station S0 near shore to Station S6 beyond the barrier islands, June 2, 2006 (refer to 

above map in Figure 3-16 for transect location). From Trefry et al. (2009). 

Turbidity and TSS concentrations did not follow the same mixing trends found for salinity as 

sediment particles settled out of the water column. This pattern can be seen clearly in the 

turbidity profile where concentrations increase in the lower water column over time even though 

these bottom waters are marine and unmixed in terms of salinity and temperature characteristics 

(Figure 3-18). 

Five moorings were deployed during 2006 from the ice surface with sensors located at a depth of 

2 m (~0.5 m below the ice canopy). The time series plots from these moorings show trends from 

Station SON-1 near shore to Station SON-4 located 4.5 km offshore . At the time of deployment 

on May 22, the Sagavanirktok River plume had already reached SON-1; salinity decreased and 

temperature increased over the next few days. The under-ice plume first reached SON-3, located 

3 km from SON-1, about 6 days later; another 3 days passed before the plume reached SON-4 

located 1.5 km from SON-3. Based on these two traverse times for the plume, the under-ice 

plume and associated currents were traveling at approximately 5 to 6 cm/s (0.5 km/day). These 

under-ice current estimates agree with the ADCP under-ice current measurements made by 

Weingartner (2006) during the breakup of the Sagavanirktok River in 2002 and with our data for 
63 

2004 that showed an average under-ice current of 7 ± 3 cm/sec. The time series plots for 

turbidity indicated that turbidity initially increased but later decreased as particles settled out. In 

contrast, salinity and temperature showed consistent trends of increasing temperature and 

decreasing salinity in the plume as a function of time. 

3.1.3.4 10BDispersion of Chemicals Under Ice in the Beaufort Sea During Spring 2006 

Concentrations of dissolved As increased linearly across the freshwater-seawater mixing zone 

for the Sagavanirktok River under-ice plume into the Beaufort Sea (Figure 3-20a). The trend was 

similar to that observed during May-June 2004 with a similar slope and range in concentrations 

of dissolved As at the seawater endmember. The trend for dissolved Cd was similar to that 

observed for As because concentrations increased with increasing salinity (Figure 3-20b). For 

both As and Cd, the trends once again reinforce the observation that the key sources of As and 

Cd were from upwelling of deeper water on to the shelf. The trend for Ba was opposite of that 

observed for As and Cd with a linear decrease offshore and data that support a minor degree of 

desorption of Ba from particles at low salinities (Figure 3-20c). Trends for Cr, Cu and Zn show 

relatively uniform values from salinities of 2 to 32; however, in each case, the higher 

concentrations observed in the rivers were not observed in the coastal Beaufort Sea (Figure 3-

20d). 

Concentrations of TSS were very low along the freshwater-seawater mixing zone from the 

Sagavanirktok River with all TSS concentrations at salinities >2‰ of <10 mg/L, except for one 

value of 20 mg/L. In 2004, most of the TSS concentrations at salinities of 2 to 20‰ were >10 

mg/L with at least half >20 mg/L. This trend is most likely due to the much higher flow and 

longer duration of high flow in the Sagavanirktok River in 2004 compared to 2006 (Figure 3-1). 

There was a six-fold difference in peak concentrations of TSS in the Kuparuk River versus the 

Sagavanirktok River during May-June 2006. On a relative basis, concentrations of TSS in the 

Kuparuk River decreased less along the salinity gradient than observed for the Sagavanirktok 

River; however, the absolute TSS values were similar along the two different freshwaterseawater mixing zones. 

Concentrations of Fe in suspended sediments from the Sagavanirktok River and its seaward 

plume plotted within, or very close, to the 99% prediction interval developed for Fe versus Al 

using sediments from the coastal Beaufort Sea (Figure 3-21a). In contrast, most of the data points 

for the Kuparuk River and under-ice plume plotted above the upper prediction interval 

(Figure 3-21b). This has been a recurrent trend that emphasizes differences in the composition 

and drainage basins of the two rivers as well as supporting a much larger role for the 

Sagavanirktok River as a source of sediments to the cANIMIDA study area than the Kuparuk 

River. 
64 

Figure 3-20. Concentrations of dissolved As (a), Cd (b), Ba (c), and Cr (d) versus salinity across 

the freshwater-seawater mixing zone from the Sagavanirktok River to the coastal 

Beaufort Sea. Solid lines and equations are from linear regression calculations. Dashed 

lines show 95% prediction intervals and r is the correlation coefficient. 

From Trefry et al. (2009). 

Figure 3-21. Concentrations of Fe versus Al for suspended sediments from the Sagavanirktok 

River (a) and Kuparuk River (b) and respective offshore, under-ice plumes in the 

coastal Beaufort Sea. Solid lines and equations are from linear regression analysis for 

the 1999-2002 data for bottom sediments from the coastal Beaufort Sea; dashed lines 

show 99% prediction intervals and r is the correlation coefficient. 

From Trefry et al. (2009). 

Salinity

0 5 10 15 20 25 30 35

Dissolved As (μg/L)

0.0

0.5

1.0

1.5

Y = 0.034X + 0.06

 r = 0.98

Sagavanirktok River to Sonde Transect

(a)

Salinity

0 5 10 15 20 25 30 35

Dissolved Cd (μg/L)

0.00

0.05

0.10

Y = 1.19X + 0.017

 r = 0.89

Sagavanirktok River

to Sonde Transect

(b)

Salinity

0 5 10 15 20 25 30 35

Dissolved Ba (μg/L)

0

10

20

30

40

Y = -0.44X + 22.3

 r = 0.94

Sagavanirktok River

to Sonde Transect

(c)

Salinity

0 5 10 15 20 25 30 35

Dissolved Cr (μg/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

Sagavanirktok River

to Sonde Transect

(d)

Al (%)

0 2 4 6 8 10

Fe (%)

0

2

4

6

8

Sagavanirktok 

SONDE

y = 0.49x + 0.18

r = 0.94, n = 196

Linear regression line and 99% prediction

 interval based on 1999-2002 data

(a)

Al (%)

0 2 4 6 8 10

Fe (%)

0

2

4

6

8

Kuparuk

K offshore

y = 0.49x + 0.18

r = 0.94, n = 196

Linear regression line and 99% prediction

 interval based on 1999-2002 data

(b)
65 

Concentrations of Ba in essentially all suspended sediment samples from each river and plume 

plotted within the 99% prediction interval established for bottom sediments in the coastal 

Beaufort Sea. This trend supports and absence of any anthropogenic Ba inputs or reactions with 

particles from either river as they are carried seaward under the ice. 

Most concentrations of Pb, Cr, Cu and Zn in samples of suspended sediments collected in 2006 

from the Sagavanirktok River and plume plot within the 99% prediction intervals for bottom 

sediments from the coastal Beaufort Sea (Figure 3-22). In contrast, a few data points for Cr and 

Cu, and many data points for Pb and Zn, from the Kuparuk River and under-ice plume plot 

above the upper prediction interval on the metal versus Al template in bottom sediments. Some 

of the Pb and Zn concentrations may have an anthropogenic origin; however, the elevated 

concentrations of Fe in the Kuparuk River and plume samples may indicate natural scavenging 

of Fe oxides that also contain Pb and Zn. 

Al (%)

0 2 4 6 8 10

Pb (μg/g)

0

10

20

30

Sagavanirktok

SONDE

Kuparuk 

K KW Trasnsects

Y = 2.4X - 0.3

r = 0.87, n = 196

Linear regression line and 99% prediction

interval based on 1999-2002 data

Al (%)

0 2 4 6 8 10

Cu (μg/g)

0

20

40

60 Sagavanirktok

SONDE

Kuparuk 

K KW Offshore

Y = 5.8X - 4.6

r = 0.94, n = 196

Linear regression line and 99% prediction

interval based on 1999-2002 data

Al (%)

0 2 4 6 8 10

Cr (μg/g)

0

50

100

150

Sagavanirktok

SONDE

Kuparuk

K KW Transects

Y = 12.4X + 8.1

r = 0.91, n = 191

Linear regression line and 99% prediction

interval based on 1999-2002 data

Al (%)

0 2 4 6 8 10

Zn (μg/g)

0

50

100

150

200 Sagavanirktok

SONDE

Kuparuk

K KW Offshore

Y = 20.5X - 5.5

r = 0.92, n = 195

Linear regression line and 99% prediction

interval based on 1999-2002 data

Figure 3-22. Concentrations of Al versus (a) Pb, (b) Cu, (c) Cr and (d) Zn in suspended 

sediments from the Sagavanirktok and Kuparuk Rivers and their respective offshore, 

under-ice plumes in the coastal Beaufort Sea. Solid lines and equations are from linear 

regression analysis for the 1999-2002 data for bottom sediments from the coastal 

Beaufort Sea; dashed lines show 99% prediction intervals and r is the correlation 

coefficient. From Trefry et al. (2009). 
66 

3.1.4 5BThe Distribution of Suspended Sediments and Chemicals during the OpenWater Period 

Vertical profiles of salinity, temperature, and turbidity, as well as water samples for suspended 

sediments and dissolved and particulate metals were collected during the summers of 2004, 2005 

and 2006 from the coastal Beaufort Sea. Data from a small sampling project in rivers also were 

collected during the summer period during the cANIMIDA Project. 

3.1.4.1 10BSuspended Sediments and Metals in Rivers: Summer 2004, 2005 and 2006 

Sampling of rivers during summer was performed to maintain a long-term data base for 

concentrations of TSS, particulate, and dissolved metals (Tables 3-5, 3-6, 3-7, and 3-8). 

Concentrations of TSS in the Kuparuk River during summers of 2004, 2005 and 2006 averaged 

1.0 mg/L, about 25 to 60 times lower than during the spring floods (Table 3-6). Only one 

elevated concentration of TSS (1.4 mg/L) was obtained in the Kuparuk River during the summer 

of 2004 (Table 3-6). This concentration of TSS was higher than typical values of 0.2-0.6 mg/L in 

previous years and in two out of three samples in 2005 and 2006. The slightly higher 

concentrations observed probably were due to increased construction activity in the area west of 

the bridge where we sampled. Concentrations of TSS in the Sagavanirktok River were more 

variable during summer with a range of 0.5 to 53.4 mg/L (Table 3-5). An increase in TSS 

concentrations >1-2 mg/L was typically linked to a rain event that raised flow and TSS 

(Table 3-5). During 2004, a rain storm raised the water flow rate and concentrations of TSS to 

53 mg/L in the Sagavanirktok River on August 3. All TSS concentrations during summer were 

10 to >300 times lower than during the spring melt. 

Table 3-5. Concentrations of particulate metals, total suspended solids, and particulate organic 

carbon in Sagavanirktok River water in the spring and summer of 2004, 2005, and 2006. 

From Trefry et al. (2009). 

Metal Summer 

2004 (n=2) 

Spring 2004 

(n=9) 

Summer 

2005 (n=2) 

Summer 

2006 (n=1) 

Spring 2006 

(n=12) 

Aluminum (Al) (%) 4.12 - 6.66 5.2 - 6.9 4.18 - 4.53 6.91 4.7 - 7.8 

Arsenic (As) (μg/g) 9.9 - 10.3 5.4 - 17.0 11.6 - 12.0 7.6 4.7 - 7.8 

Barium (Ba) (μg/g) 561 - 743 578 - 733 644 - 668 625 433 - 780 

Cadmium (Cd) 

(μg/g) 0.71 - 1.12 0.52 - 0.83 1.0 - 1.39 0.67 0.44 - 0.70 

Chromium (Cr) 

(μg/g) 102 - 105 41.1 - 88.8 96 - 102 113 68.2 - 122 

Copper (Cu) (μg/g) 32.0 - 38.0 23.6 - 38.6 28.8 - 35.1 31.8 23.2 - 40.9 

Iron (Fe) (%) 3.35 - 3.87 3.1 - 3.5 3.46 - 3.48 3.65 2.0 - 4.6 

Lead (Pb) (μg/g) 10.7 - 19.4 9.8 - 13.6 11.7 - 12.0 19.3 11.0 - 26.8 

Zinc (Zn) (μg/g) 87.9 - 144 115 - 161 106 - 117 167 109 - 208 

Total Suspended 

Solids (TSS) (mg/L) 1.45 - 53.4 43 - 285 0.50 - 1.36 8.9 9.5 = 353 

Particulate Organic 

Carbon (POC) (%) 0.6 - 1.0 0.8 - 1.5 --- 1.3 1.2 - 3.0 
67 

Table 3-6. Concentrations of particulate metals, total suspended solids, and particulate organic 

carbon in Kuparuk River water in the spring and summer of 2004, 2005, and 2006. From 

Trefry et al. (2009). 

Metal Summer 

2004 (n=1) 

Spring 2004 

(n=8) 

Summer 

2005 (n=2) 

Summer 

2006 (n=1) 

Spring 2006 

(n=11) 

Aluminum (Al) (%) 3.44 5.5 - 6.7 2.44 - 3.47 4.01 3.5 - 6.6 

Arsenic (As) (μg/g) 7.6 3.9 - 13.1 6.3 - 20.6 12.4 4.7 - 11.6 

Barium (Ba) (μg/g) 551 573 - 805 495 - 667 448 450 - 725 

Cadmium (Cd) 

(μg/g) 0.20 0.30 - 0.52 0.70 - 2.56 6.6 0.35 - 0.71 

Chromium (Cr) 

(μg/g) 43.7 57.1 - 82.4 85.8 - 97.6 76.6 41.6 - 97.2 

Copper (Cu) (μg/g) 29.4 28.7 - 45.1 18.6 - 25.2 31.9 20.5 - 34.1 

Iron (Fe) (%) 3.06 3.7 - 4.3 2.39 - 3.28 4.59 3.2 - 4.6 

Lead (Pb) (μg/g) 15.7 5.0 - 6.5 5.9 - 17.0 38.0 12.1 - 23.7 

Zinc (Zn) (μg/g) 131 112 - 130 59.3 - 96.5 155 109 - 191 

Total Suspended 

Solids (TSS) (mg/L) 1.35 32 - 130 0.19 - 2.0 0.39 4.6 - 59.7 

Particulate Organic 

Carbon (POC) (%) 3.9 1.6 - 4.9 1.1 8.6 2.6 - 7.8 

At typical concentrations of TSS in summer (~2 mg/L), concentrations of particulate metals and 

organic carbon in the Sagavanirktok River were lower than in spring (Table 3-5) but close to 

results obtained during summer for previous years (Trefry et al., 2004a,b). After the 2004 

rainstorm, the concentrations of particulate metals increased to levels that were closer to those 

for particulate metals in spring 2004, except for Pb (Table 3-5). The rain seems to have carried in 

particles that were slightly more Pb-rich than typically observed (duplicate samples with Pb at 

19.0 and 19.9 μg/g), perhaps representing a contribution from road runoff or deposition with 

rain. 

Concentrations of dissolved metals in the Sagavanirktok River following the summer rain in 

2004 were higher than in the pre-rain river water with concentrations of Cu and Pb ~3 times 

higher following the rain (Tables 3-7). 

Concentrations of dissolved metals in the Kuparuk River during summer showed variations that 

were similar to those observed for the Sagavanirktok River with overall higher values for As and 

Cu and lower concentrations of Cd, and Pb in the Kuparuk River relative to the Sagavanirktok 

River (Tables 3-7 and 3-8). 

The percent of total metal in the rivers that was dissolved increased greatly during summer due 

to much lower values for TSS during summer. For example, the % dissolved Ba in the 

Sagavanirktok River increased from an average of ~30% in May-June to >97% in summer 2005. 

Even the % dissolved Pb increased from <5% in May-June to >20% in summer for the 

Sagavanirktok River. Similar trends were found for each year when spring and summer data 

were compared. 
68 

Table 3-7. Concentrations of dissolved metals in the Sagavanirktok River in the spring and 

summer of 2004, 2005, and 2006. From Trefry et al. (2009). 

Table 3-8. Concentrations of dissolved metals (μg/L) in the Kuparuk River in the spring and 

summer of 2004, 2005, and 2006. From Trefry et al. (2009). 

River Value As Ba Cd Cr Cu Pb Zn 

Kuparuk 

Spring 2004 

(n=8) 

Mean 

±SD 

Min -

Max 

0.041 

(n=1) 

7.0±1.5 

3.5-8.6 

0.014 

±0.003 

0.01-0.019

0.085 

(n=1) 

0.21±0.14 

0.05-0.49 

0.011 

±0.008 

0.003-

0.023 

0.35±0.19 

0.16-0.69 

Kuparuk 

Summer 

2004 (n=1) 

--- 0.161 35.8 0.002 0.147 0.858 0.014 0.28 

Kuparuk 

Summer 

2005 (n=2) 

--- 0.080-

0.084 41.8-52.2 0.002-

0.002 

0.083-

0.088 

0.630-

0.630 

0.013-

0.013 0.18-0.18 

Kuparuk 

Spring 2006 

(n=10) 

Mean±

SD 

Min -

Max 

0.089 

±0.028 

0.061-

0.153 

25.2±19.1 

16.8-79.3 

0.008 

±0.004 

0.003-

0.013 

0.115 

±0.022 

0.078-

0.152 

0.57 

±0.019 

0.35-0.99 

0.038 

±0.013 

0.020-

0.062 

0.82±0.57 

0.37-2.37 

Kuparuk 

Summer 

2006 (n=1) 

--- 0.081 40.6 0.012 0.081 0.626 0.019 0.11 

Colville 

Summer 

2006 (n=1) 

--- 0.141 59.0 0.012 0.107 1.06 0.026 0.13 

River As 

(μg/L) 

Ba 

(μg/L) 

Cd 

(μg/L) 

Cr 

(μg/L) 

Cu 

(μg/L) 

Pb 

(μg/L) 

Zn 

(μg/L) 

Sagavanirktok 

Summer 2004 

(n=2) 

- 0.126 

0.174 

38.0 

31.8 

0.009 

0.003

0.166 

0.160 

0.233 

0.661 

0.004 

0.010 

0.18 

0.21 

Sagavanirktok 

Spring 2004 

(n=9)

Mean 

Std. Dev. 

Min. 

Max. 

0.068 

±0.015 

0.048 

0.086 

19.0 

±1.8 

16.1 

22.6 

0.018 

±0.006 

0.010 

0.025 

0.096 

±0.17 

0.080 

0.110 

0.50 

0.17 

0.34 

0.88 

0.013 

±0.006 

0.007 

0.023 

0.28 

±0.08 

0.19 

0.40 

Sagavanirktok 

Summer 2005 

(n=2) 

- 0.096 

0.102 

41.6 

44.8 

0.003 

0.004

0.108 

0.137 

0.264 

0.196 

0.004 

0.004 

0.14 

0.13 

Sagavanirktok 

Summer 2006 

(n=1) 

- 0.076 35.8 0.033 0.126 0.547 0.007 0.17 

Sagavanirktok 

Spring 2006 

(n=12)

Mean 

Std. Dev. 

Min. 

Max. 

0.069 

±0.016 

0.054 

0.108 

25.2 

±1.9 

22.6 

28.0 

0.012 

±0.004 

0.007 

0.016

0.147 

±0.027 

0.118 

0.206 

0.79 

0.38 

0.46 

1.6 

0.031 

±0.006 

± 

0.039 

1.0 

±1.0 

0.3 

3.6 
69 

Values for log Kd in the summer samples were within the range of values found for spring for 

As, Cr and Zn in the Sagavanirktok River, but lower in summer than spring for Ba, and higher in 

summer than spring for Cd, Cu, and Pb. For the Kuparuk River, the log Kd values for summer 

were within the range of values for spring for As, Cu, Pb and Zn, lower for Ba and Cu and higher 

for Cd. To some degree, the distribution coefficients are conditional constants that respond to 

variations in mineralogy and surface area of the particles. Overall, the Kd values provide a first 

order approximation of the dissolved concentrations of metals as a function of metal 

concentrations of the suspended sediments. 

3.1.4.2 102BSuspended Sediments and Metals Offshore – Summer 2004, 2005, 2006

In 2004, 2005, and 2006 salinity, concentrations of suspended sediments and turbidity, and 

particulate and dissolved metals in the water column were monitored at several of the nearshore 

stations off the Sagavanirktok and Kuparuk Rivers, and at selected stations near Northstar, in the 

Liberty prospect, and historic BSMP stations (Figures 2-2 and 2-3). 

Typically, salinities in the upper layer of the water column increased between early June and late 

July as break-up of the ice cover was followed by mixing due to wind. Bottom water salinity was 

essentially unchanged. The water column remained stratified. 

Turbidity was high throughout the water column at most sites in late-July and August, 2004. 

Both salinity and turbidity were uniform to a depth of ~5 m at most stations in August, due to 

active mixing during relatively strong winds. However, in shallow water (<5 m), the salinity and 

turbidity profiles were uniform from top to bottom. The overall absolute values for TSS and 

turbidity during the open-water period were directly related to wind conditions (Trefry et al., 

2004a). Thus, during a given summer, the mean and range of measured TSS concentrations 

typically reflected the winds and weather. 

There were higher mean concentrations of TSS in 1999, 2000 and 2004 relative to 2001, 2002, 

2005 and 2006 in the cANIMIDA area collectively as well as in the area of Northstar Island 

(Table 3-9). The very high TSS concentrations in 1999 are anomalous relative to the complete 

data set. Northstar Island was not constructed until winter 2000. However, much of the 1999 data 

were collected following a 5-day storm with >20 knot winds. In contrast, 2002, 2005 and 2006 

data were collected during relatively calm conditions with considerable sea ice throughout the 

study area. During the 2000, 2001, and 2004 sampling periods, conditions were moderate with 5 

to 15 knot winds during most of the sampling period. Furthermore, more samples from deeper 

water, seaward of the barrier islands are included in the mean values for 2005 and 2006. During 

2004, relative calm was encountered during most of the study period as reflected in the low mean 

value for TSS in the Northstar area and in much of the rest of the study area (Table 3-9). The 

strong winds late in the 2004 study period yielded the high maximum value of 64 mg/L TSS east 

of Endicott. Relatively little sediment resuspension is required to increase the TSS concentration 

in shallow offshore waters. For example, a layer of fine sediment only 0.02 cm thick would need 

to be resuspended and mixed through 8 m of water column to yield TSS concentrations of 40 

mg/L. 

The data presented here and from many vertical profiles and horizontal tows presented in 

previous reports (Trefry et al., 2004a) show no significant differences in turbidity or 

concentrations of TSS in proximity (within 100 to 500 m) to Northstar Island relative to other 
70 

Table 3-9. Summary data for total suspended solids (TSS) for all stations in the ANIMIDA and 

cANIMIDA study area during the open-water period and for a subset of stations in the 

area of Northstar Island. From Trefry et al. (2009). 

All Stations 

Year n 

TSS 

Mean ± SD 

(mg/L) 

TSS 

Maximum 

(mg/L) 

TSS 

Minimum 

(mg/L) 

1999 31 30 ± 27 119 2.9 

2000 51 8.2 ± 4.8 26 1.7 

2001 34 5.1 ± 2.1 8.7 0.9 

2002 32 2.1 ± 1.3 4.4 0.2 

2004 45 13 ± 16 64 0.5 

2005 65 1.7 ± 1.4 6.7 0.3 

2006 26 1.3 ± 0.7 4.0 0.4 

Northstar Area n TSS TSS TSS

1999 17 38 ± 33 119 2.9 

2000 35 7.3 ± 4.0 16 1.7 

2001 15 4.1 ± 1.8 6.3 0.9 

2002 11 2.5 ± 1.5 4.4 0.2 

2004 15 6.2 ± 4.8 16 0.5 

2005 9 1.4 ± 0.8 3.6 0.8 

2006 12 1.1 ± 0.4 2.1 0.6 

locations in the ANIMIDA study area. This result is consistent with the coarse-grained 

composition of the original sand and gravel used to construct the island and the armoring that 

covers the slope of the island to the seafloor. 

Concentrations of particulate metals in the open-waters of the Beaufort Sea varied with the 

organic matter and clay concentrations in the particles. The grand averages for 2000, 2001, 2002, 

2004, 2005, and 2006 in Table 3-10 show some interannual variability; however, most of the 

variations are due to differences in the composition of the suspended sediments as shown by 

variations in concentrations of Al and Fe and generally comparable shifts in concentrations of 

trace metals. Average concentrations of Al, Fe and trace metals in bottom sediments (Table 3-10) 

are lower than found in suspended sediments because the bottom sediments contain more quartz 

sand and carbonate shell material, both of which contain low metals concentrations, diluting 

concentrations of trace metals in whole sediments. Thus, any comparisons of metal 

concentrations between suspended sediments and bottom sediments are made based on metal/Al 

ratios. 

Concentrations of particulate metals in the water column in the Northstar area were not 

significantly different from values obtained throughout the cANIMIDA area during 2004, 2005 

and 2006 with the exception of Cd in 2004 and Pb in 2006. The Cd anomaly probably is due to 

high concentrations of particulate organic matter (plankton), as shown by the lower Al content in 

the 2004 samples of suspended sediment from the Northstar area. The slightly elevated 

particulate Pb concentration may be related to trace amounts of input from flaring or other island 

operations. 
71 

Table 3-10. Mean concentrations of particulate metals in water samples collected from the 

coastal Beaufort Sea and near Northstar Island (NS) during the open-water season. From 

Trefry et al. (2009). 

Year Al (%) As (μg/g) Ba (μg/g) Cd (μg/g) Cr (μg/g) Cu (μg/g) Fe (%) Pb (μg/g) Zn (μg/g)

2000 (n=51) 7.4 21 738 0.66 104 40 4.3 30 154 

2001 

(n=34) 8.0 21 775 0.49 111 48 4.8 27 132 

2002 (n=32) 5.9 28 564 0.72 82 39 4.1 21 103 

2004 Areawide (n=42) 6.9 22 680 0.54 105 31 4.0 19 137 

2004 NS 

(n=7) 6.3 18 674 0.91 90 38 3.8 21 144 

2005 Areawide (n=65) 4.9 22 507 1.4 99 31 3.6 19 124 

2005 NS 

(n=9) 5.0 27 581 1.0 106 27 3.7 18 108 

2006 Areawide (n=26) 5.7 25 574 1.1 88 36 3.9 22 161 

2006 NS 

(n=12 5.7 26 598 1.0 84 39 4.1 30 163 

Beaufort Sea 

Sediment 3.9 11 394 0.22 57 19 2.3 10 70 

Some concentrations of Cd in suspended sediments show a good fit to the sediment prediction 

intervals, whereas others show a negative trend versus Al for data that plotted above the upper 

prediction interval on the Cd versus Al plot (Figure 3-23). The higher concentrations of Cd at 

lower Al concentrations may be related to high Cd concentrations in plankton, up to several 

μg/g. In contrast, the higher As concentrations in suspended sediments at lower concentrations of 

Al (Figure 3-23) cannot be related to plankton because all plankton had As concentrations <8 

μg/g. The excess As probably is bound to fine-grained Fe oxides. 

Concentrations of dissolved trace metals were determined in seawater samples from the coastal 

Beaufort Sea during both the ANIMIDA and cANIMIDA Projects (Table 3-11). Concentrations 

of dissolved As, Cr, and Pb were lower than reported values for surface seawater worldwide. 

Lower As concentrations were found because dissolved As concentrations increase with 

increasing salinity. In contrast, concentrations of dissolved Cd, Cu, and Zn were higher than in 

typical surface seawater. Concentrations of dissolved Cd in summer were about 50% lower than 

values obtained in winter. Concentrations of dissolved Cd, at 14 to 18 ng/L, in rivers were lower 

than in seawater at any time of year. Concentrations of dissolved Ba were similar to those in 

typical surface seawater, except during 2000 and 2001, when a more nearshore samples were 

collected. Dissolved Ba concentration usually were lower in seawater (10 to 32 μg/L), than in 

river water. Concentrations of dissolved Ba averaged 20, 26, and 50 μg/L for the Kuparuk, 

Sagavanirktok and Colville rivers, respectively (Table 3-3). 
72 

Figure 3-23. Concentrations of particulate (a) Cd and (b) As versus particulate Al in suspended 

sediment samples collected during May-June (Spring) and July-August (Summer) 

2004. Solid and dashed lines show the linear regression fit and prediction interval 

based on data for bottom sediments. From Trefry et al. (2003, 2009). 

All dissolved metals concentrations were in the range of background values and these values are 

well below the EPA water quality criteria for chronic effects in marine organisms (Table 3-11). 

Furthermore, concentrations of dissolved metals were not significantly different in the Northstar 

area than in the overall cANIMIDA study area. 

The observed enrichment of dissolved Cd in the coastal Beaufort Sea during summer is 

consistent with the global Cd/P relationship for seawater; however, such high concentrations of 

dissolved Cd are unusual for surface seawater. The cANIMIDA study area probably has low 

concentrations of dissolved nitrate such that the N:P ratio of the seawater inside the barrier 

Particulate Al (%)

0 2 4 6 8 10

Particulate Cd (μg/g)

0.0

0.5

1.0

2.0

4.0

6.0 Spring 2004

Summer 2004

(a)

Al (%)

0 2 4 6 8 10

As (μg/g)

0

20

40

60

80

Spring 2004

Summer 2004

(b)
73 

Table 3-11. Mean concentrations of dissolved metals and salinity in seawater water collected from the 

coastal Beaufort Sea and near Northstar Island during the open-water season in 2000 through 

2006. All dissolved metal concentrations are μg/L (parts per billion). From Trefry et al. (2009). 

a

 Donat and Bruland (1995).

b

 USEPA (2009). 

c

 Criterion for trivalent chromium. 

d Criterion for inorganic mercury. 

islands during summer is typically <1 (rather than 16:1) as is typical for seawater. Dissolved Cd, 

phosphate, and nitrate move onto the inner shelf during upwelling of deeper, offshore water. 

Carmack and MacDonald (2002) showed that seawater (salinity 34‰) at a water depth of several 

hundred meters in the Canadian Beaufort Sea has an N/P ratio of ~8:1. As this water is moved 

Year Salinity As Ba Cd Cr Cu Hg Pb Zn 

2000 

(n = 49) 

22 0.49 26.8 0.02 0.06 0.54 0.0005 0.005 0.20 

2001 

(n = 34) 

17 0.38 31.9 0.02 0.09 0.64 0.001 0.01 0.16 

2002 

(n = 31) 

20 0.51 14.2 0.03 0.07 0.47 0.0009 0.07 0.11 

2004 

Area wide 

(n = 42) 

23 0.72 13 0.04 0.11 0.36 - 0.01 0.16 

2004 NS 

(n =7) 

25 0.81 12 0.04 0.10 0.40 - 0.01 0.14 

2005 

Area wide 

(n = 65) 

27 0.93 10.6 0.05 0.09 0.31 0.0007 0.01 0.32 

2005 NS 

(n = 9) 

25 0.88 11.5 0.04 0.09 0.30 0.0008 0.02 0.28 

2006 

Area wide 

(n = 26) 

23 0.60 13 0.04 0.09 0.31 - 0.008 0.17 

2006 NS 

(n =12) 

21 0.56 14 0.03 0.08 0.31 0.007 0.20 

Average 

Surface 

Seawatera

35 1.2 13 0.01 0.16 0.10 0.0002 0.02 0.1 

EPA 

Marine 

Water 

Quality 

Criteriab

Chronic 36 - 8.8 50c 3.1 0.94d 8.1 81 
74 

up onto the outer shelf, the N/P ratio is <5:1 (salinity of 30-32‰). Increased depletion of nitrate, 

relative to phosphate continues into the nearshore area (such as Stefansson Sound) such that the 

N/P ratio becomes <1 in summer and the Cd/P ratio is consistent with global seawater values. 

However, in winter, concentrations of dissolved Cd are high (~0.50 ng/L) when concentrations 

of dissolved phosphate are low (<0.1 μM). 

As discussed previously, concentrations of dissolved Cd in the Arctic rivers are lower than in 

offshore water; thus, upwelling is an important source of dissolved Cd to the study area. 

Suspended matter with lower concentrations of Al contains high concentrations of Cd in both 

spring (under ice) and summer. Such enrichment is typical of plankton and was also observed for 

Cu. 

3.1.5 56BHydrocarbons in River Sediments, Peat, Northstar Oil and Nearshore Seawater 

Concentrations of hydrocarbons were measured in river sediments, coastal peat, and Northstar 

crude oil in one or more of the BSMP Program (Boehm et al., 1987)), Task 2 of the ANIMIDA 

Project (Brown et al., 2004), and Task 2 of the cANIMIDA Project (Brown et al., 2010). PAH 

were measured in the dissolved and particulate fractions of seawater from the Northstar, Liberty, 

and BSMP areas in ANIMIDA Task 7 (Trefry et al., 2004b). The objective of this work was to 

help identify sources of hydrocarbons in sediments and marine animal tissues in the vicinity of 

the Northstar production facility and the Liberty prospect. 

3.1.5.1 103BHydrocarbons in River Sediments 

Sediment samples were collected for hydrocarbon analysis from the mouth of the Sagavanirktok, 

Kuparuk, Colville, and Canning Rivers between 1985 and 2002. Concentrations of total PAH, 

SHC, and StTr were quite variable in these North Slope river sediments, both among the rivers 

and among years (Table 3-12). Highest TPAH concentrations were in some Colville River 

sediment samples collected in all years. These river sediment samples also contained relatively 

high concentrations of TSHC and TStTr. The high hydrocarbon concentrations did not seem to 

be related closely with TOC concentration or % silt + clay (mud) in the sediments. 

The PAH, SHC, and StTr profiles of typical river sediment samples indicate a mixed petrogenic, 

pyrogenic, and biogenic source (Figure 3-24). The SHC fraction is characterized by abundant 

longer chain-length alkanes (C25 - C29) and a relatively high carbon preference index (CPI: ratio 

of odd-numbered to even-numbered alkanes), both characteristic of terrestrial plant material 

(Boehm, 1984). The greater abundance of the triterpane, T22, over T21 in Kuparuk and 

Sagavanirktok River sediments and the abundance of T15 in Colville River sediments also 

indicates the presence of recent diagenic plant material (Douglas et al., 2007). The greater 

abundance of alkyl naphthalenes, phenanthrenes, and fluoranthenes/pyrenes than the unalkylated parent PAH and higher molecular weight PAH is characteristic of a petroleum source, 

whereas, the higher molecular weight 4- through 6-ring PAH are primarily from pyrogenic 

(combustion) sources (Douglas et al, 2007). The exception is perylene, which is a primarily 

recent biogenic PAH, derived from transformation of natural plant material in oxygen-free 

sediments (Venkatesan, 1988; Silliman et al., 1998). 
75 

Table 3-12. Concentrations of TPAH, TSHC, TSrTr, TOC, and silt + clay (mud) in river 

sediments collected in 1985/86 (Boehm et al., 1987) and 1999-2002. From Brown et al. 

(2005). 

River Year Total PAH 

(ng/g) 

Total SHC 

(ng/g) 

Total StTr 

(ng/g) TOC (%) Mud (%) 

Sagavanirktok River 

1985/86 210 - 460 8700 - 14,000 --- 4.2 - 18.5 16 

1999 317 3500 25.4 --- --- 

2000-02 33.3 - 670 1680 - 18,000 30 - 65 2.8 --- 

Kuparuk River 

1986 50 4100 --- 4.2 56 

1999 102 3500 72.4 4.72 --- 

2000/02 8.6 - 161 550 - 22,000 2.2 - 140 7.4 --- 

Colville River 

1985/6 660 - 700 8300 - 11,000 --- 6.6 - 93 69 

1999 2222 - 2634 1630 - 1660 345 1.61 - 2.44 --- 

2000 140 - 2024 320 - 25,000 2.19 - 282 0.42 - 7.39 2.4 - 39 

2002 695 5200 73 --- --- 

Canning River 1986 190 1200 --- 41 66 

2002 195 - 490 9100 - 19,000 18 - 23 --- --- 

3.1.5.2 1Hydrocarbons in Coastal Peat 

Peat is formed by the deposition and slow biodegradation and abiotic rearrangement (diagenesis) 

of plant material in suboxic soils and sediments. It is an early diagenic stage in the formation of 

petroleum, coal, and gas (Neff, 2002a). Extensive peat bogs formed in the Alaskan tundra with 

the warming climate that followed each period of glaciation (Jones and Yu, 2010). Upon burial, 

peat is converted to kerogens (humates and lignites), hard coal, petroleum, and natural gas by 

millions of years of exposure to high temperatures and pressures. These peat, kerogen, and coal 

deposits are continually being eroded by the North Slope rivers and crumbling of the coastal 

shoreline. Chemical rearrangements during diagenesis convert plant debris into the complex 

mixture of saturated, naphthenic, and aromatic hydrocarbons, and complex polar organic 

compounds, characteristic of peat, coal, and petroleum. Surface or shallow sub-surface Holocene 

(deposited during the last ~12,000 years) deposits of peat and kerogen, such as those frequently 

found in permafrost tundra soils and in shallow layers of offshore sediments, may contain high 

concentrations of SHC, PAH, and StTr with both biogenic/diagenic and petrogenic properties. 

Peats have a strong sorptive capacity for PAH. A large fraction of the PAH in North Slope peat 

probably is pyrogenic (Venkatesan and Kaplan, 1982), derived from aerial deposition of 

combustion carbon from the Arctic aerosol. 

Several samples of peat from near the mouths of Arctic rivers, and from eroding deposits along 

the coasts were analyzed for SHC, PAH, and StTr as part of the BSMP, ANIMIDA, and 

cANIMIDA Projects (Boehm et al., 1987; Brown et al., 2004, 2010) (Table 3-13). Total PAH 

concentrations ranged from 13 to 740 ng/g dry wt (parts per billion). As expected total SHC 

concentrations in the peat were much higher, ranging from 8700 to 260,000 ng/g. Most peat 

samples contained comparatively low concentrations of total StTr; highest concentrations were 

in Kuparuk River sediments, probably because the Kuparuk River drains primarily Arctic tundra 

soils. There were no clear relationships among concentrations of PAH, SHC, StTr, and TOC in 

the Arctic peat. 
76

Figure 3-24. SHC, PAH, and StTr profiles in river sediments collected in 2002. SHC. PAH, and 

StTr acronyms are defined in Table, 2-4 - 2-6. Data from Brown et al. (2005).
77 

Table 3-13. Concentrations of TPAH, TSHC, TSrTr, TOC, and silt + clay (mud) in river or 

coastal peat collected in 1985/86 (Boehm et al., 1987), 2000/02 (Brown et al., 2005), and 

2006 (Brown et al., 2010). 

River Year Total PAH 

(ng/g) 

Total SHC 

(ng/g) 

Total StTr 

(ng/g) TOC (%) 

Sagavanirktok River 2002 160 41,000 38 --- 

2006 290 25,000 41 --- 

Kuparuk River 

2000 100 18,000 51 2.4 

2002 140 - 450 71,000 - 72,000 92 - 390 --- 

2006 110 57,000 35 --- 

Colville River 2002 360 50,000 110 --- 

2006 740 47,000 83 --- 

Canning River 1985 410 84,000 --- 1.7 

Arey Lagoon 1985 620 260,000 --- 0.95 

Flaxman Island 1985 170 39,000 --- 0.42 

Tigvariak Island 1985 180 230,000 --- 2.3 

Heald Point 1985 50 83,000 --- 0.93 

Milne Point 1985 200 240,000 --- 2.6 

Cape Halkett 1985 710 41,000 --- 0.23 

Kogru Island 1885 50 600,000 --- 3.0 

Eskimo Island 2006 120 230,000 87 --- 

Pingok Island 2006 13 8700 3.0 --- 

Profiles of SHC, PAH, and StTr in representative river peat samples (Figure 3-25) were 

somewhat different from those for river sediments (Figure 3-24). The SHC profiles contained a 

broader range of abundant alkanes, extending from C21 to C33 or C34, compared to C23 to C31 

in river sediments. However, the CPI was high in both river sediments and peat, indicating a 

predominantly terrestrial plant origin for the hydrocarbon assemblages. 

The river sediment and river peat samples had similar PAH profiles (Figures 3-24 and 3-25). The 

greater abundance of alkyl naphthalenes and alkyl phenanthrenes compared to parent 

naphthalene and phenanthrene was even more prominent in the peat than in the sediments, 

primarily because of the lower relative concentration of perylene in the peat than in the river 

sediments. The PAH assemblage in the peat samples is indicative of a mixture of petrogenic and 

biogenic PAH, with a smaller contribution of pyrogenic PAH. 

The StTr profiles are characteristic of a relatively recent (Holocene) plant origin. Thus, the peat 

shows a transitional phase between biogenic to petrogenic characteristics, with some pyrogenic 

PAH, possibly from aerial deposition. 
78 

Figure 3-25. SHC, PAH, and StTr profiles in river peat collected in 2006. SHC, PAH, and StTr 

acronyms are defined in Table, 2-4 - 2-6. Data from Brown et al. (2010). 

0

2

4

6

8

10

12

14

C9

C10

C11

C12C13

1380

C14

1470

C15C16

1650

C17

Pristane

C18

Phytane

C19C20C21C22C23C24C25C26C27C28C29C30C31C32C33C34C35C36C37C38C39C40

% Total SHC

Kuparuk R TSHC = 226,670 ppb

Sag R TSHC = 25,019 ppb

Colville R TSHC = 47,092 ppb

0

1

2

3

4

5

6

7

8

9

10

N

C1NC2NC3NC4N

BIP

ACEACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaA

C

C1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

% TPAH

Kuparuk R TPAH = 120 ppb

Sag R TPAH = 291 ppb

Colville R TPAH = 737 ppb

0

5

10

15

20

25

30

35

40

45

T4 T9 T10 T11 T12 T15 T18 T19 T21 T22 S4 S5 S24 S25 S28 S28a

% Total StTr

Kuparuk R TStTr = 87.3 ppb

Sag R TStTr = 40.9 ppb

Colville R TStTr = 83.1 ppb
79 

3.1.5.3 105BHydrocarbons in Northstar Crude Oil 

Samples of Northstar crude oil were collected several times during the cANIMIDA Project for 

hydrocarbon analysis. Northstar crude oil is a light crude oil (oAPI = 40.8 @ 15oC). Mean 

concentrations of total SHC, total PAH, and total StTr in the unweathered oil were 642,770. 

15,260, and 324 mg/kg oil, respectively. The SHC, PAH, and StTr profiles of the crude oil 

(Figure 3-26) were quite different from those of river sediments (Figure 3-23) and river peat 

(Figure 3-24). The relative abundance of alkanes decreased with increasing carbon number. The 

isoprenoid alkanes, including pristane and phytane, were less abundant than the n-alkanes of 

similar molecular weight. The CPI index was approximately 1, characteristic of petrogenic 

hydrocarbon mixtures. 

The most abundant PAH were alkyl naphthalenes, with the C2-alkylnaphthalene the most 

abundant (Figure 3-26). Alkyl phenanthracenes were the next most abundant PAH. As is 

frequently the case, especially with light crude oils, more than 95% of the total PAH were 2- and 

3-ring compounds. The concentrations of the high molecular weight PAH, including biogenic 

perylene, were very low, usually below the method detection limit. This is a characteristic PAH 

profile of a light crude oil. 

The most abundant StTr in Northstar crude oil were S4 (13β,17α-diacholestane(20S), T19 

(17α(H),21β(H)-hopane), and T4 (C23 Diterpane) (Figure 3-26). These compounds are 

characteristic of crude oil (Douglas et al., 2007). 

3.1.5.4 106BHydrocarbons in Nearshore Beaufort Sea Water 

Several surface seawater samples were collected for hydrocarbon analysis near the Northstar 

development, the Liberty prospect, and at a small number of BSMP stations in 2000 to 2002 as 

part of ANIMIDA Task 7 (Trefry et al., 2004b). Concentrations of TPAH and individual PAH 

were measured in whole water, the particulate fraction, and the dissolved (including colloidal) 

fraction of the seawater samples (Table 3-14). 

Whole water samples from the three areas contained 37 to 69 ng/L (parts per trillion) TPAH 

(Table 3-14). Most of the PAH in whole water were associated with the particulate fraction. 

Concentrations of dissolved PAH ranged from 13 to 19 ng/L. The low molecular weight 2- and 

3-ring PAH were much more abundant than the higher molecular weight 4- through 6-ring PAH 

in both the particulate and dissolved fractions. Concentrations of PAH were similar in whole 

water from Northstar, Liberty, and BSMP. However, concentrations of particulate PAH were 

significantly higher in water from the Liberty prospect than in water from the vicinity of the 

Northstar development and BSMP stations. 

Blank samples, particularly for the dissolved phase, contained relatively high concentrations of 

TPAH compared to concentrations in the corresponding water samples. Thus, the actual 

concentrations of dissolved, and to a much lesser extent, particulate TPAH are lower than 

reported in Table 3-14. If the blank concentrations are considered, the actual TPAH 

concentrations in whole water and the particulate and dissolved fractions, ~15 - 40 ng/L, ~11 - 

45 ng/L, and ~<1 - 6 ng/L, respectively, are in the range frequently reported for uncontaminated 

nearshore surface seawater (Neff, 2002a). 
80 

Figure 3-26. Mean SHC, PAH, and StTr profiles in Northstar crude oil collected in 2004. SHC, 

PAH, and StTr acronyms are defined in Table, 2-4 - 2-6. Data from Brown et al. 

(2010). 

0

0.5

1

1.5

2

2.5

C9

C10

C11

C12C13

1380

C14

1470

C15

1650

C16C17

Pristane

c18

Phytane

C19C20C21C22C23C24C25C26C27C28C29C30C31C32C33C34C35C36C37C38C39C40

% Total SHC

Saturated Hydrocarbon (SHC)

0

5

10

15

20

25

N

C1NC2NC3NC4N

BIP

ACEACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaACC1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

% Total PAH

Polycyclic Aromatic Hydrocarbon (PAH)

0

2

4

6

8

10

12

14

16

T4 T9 T10 T11 T12 T15 T18 T19 T21 T22 S4 S5 S24 S25 S28 S28A

% Total StTr

Sterane/Triterpane (StTr
81 

Table 3-14. Ranges of concentrations of TPAH, 2-3-ring PAH, and ≥ 4-ring PAH in the 

dissolved and particulate fractions of water samples collected as part of ANIMIDA Task 7 

(2000 to 2002). Concentrations are ng/L (parts per trillion). From Trefry et al. (2004a). 

Region Fraction TPAH 2-3-Ring PAH ≥ 4-Ring PAH 

Northstar 

Whole water 40.1 - 54.0 33.2 - 42.3 6.86 - 11.7 

Particulate 21.1 - 40.7 15.2 - 29.0 5.85 - 11.8 

Dissolved 15.9 - 18.5 15.1 - 17.6 0.73 - 0.87 

Liberty 

Whole water 59.0 - 68.5 44.4 - 50.5 14.6 - 18.0 

Particulate 48.4 - 54.8 33.8 - 36.9 14.6 - 18.0 

Dissolved 14.4 - 17.7 13.2 - 16.4 1.19 - 1.36 

BSMP 

Whole water 37.6 - 50.8 31.8 - 56.1 5.85 - 10.3 

Particulate 22.0 - 40.8 16.9 - 31.0 5.17 - 9.72 

Dissolved 13.2 - 16.9 11.9 - 15.9 0.6 - 1.34 

Water blank 

Whole water 22.6 21.5 1.55 

Particulate 9.86 9.06 0.8 

Dissolved 12.7 11.9 0.75 

The most abundant PAH in the particulate fraction of river water and nearshore seawater were 

phenanthrene and naphthalene, with lower concentrations of their alkyl homologues. The higher 

molecular weight PAH, fluoranthene, benzo(b)fluoranthene, and perylene were more abundant 

than the other high molecular weight PAH. The most abundant PAH in the dissolved fractions 

were naphthalene, alkyl naphthalenes, and phenanthrene, all of which were present in the 

dissolved sample blanks. Thus, the particulate PAH profile resembled a combined pyrogenic and 

biogenic source, whereas, the dissolved fraction contained traces of naphthalenes, possibly from 

light fuels or aerial deposition. 

PAH concentrations often are relatively high in the particulate fraction of Arctic river water and 

nearshore seawater. Yunker et al. (1993) measured several PAH in particulate and colloidal 

(same as dissolved) fractions of water from the Mackenzie River and estuary, Canada. The 

largest fraction of PAHs always was associated with the large particulate fraction (>1.2 m), 

followed by the fine particulate fraction (1.0 to 0.2 m), followed by the colloidal fraction (<0.2 

m). A water sample from the mouth of the river contained 107 ng/L, 1.2 ng/L, and 0.31 ng/L 

total PAHs in the large particle, fine particle, and colloidal phases, respectively. Most of the high 

molecular weight PAHs were associated with the >1.2-m fraction. Little or none was associated 

with the colloidal fraction. Phenanthrene and anthracene were enriched in the colloidal fraction. 

The PAH distribution reported by Yunker et al. (1993) for McKenzie River water is similar to 

that reported in the ANAMIDA Project for Alaskan river and nearshore waters. It may be caused 

by tight binding of high molecular weight PAH to the particulate (particularly the particulate 

organic carbon: POC) phases. The high molecular weight PAH are tightly bound to peat, 

kerogen, coal, and soot (the large particle phase) in the suspended particulate phase. Because of 

the tight binding of the PAH to these organic-rich particles, the particulate PAH are inert and do 

not partition into the water phase (Yunker et al., 1991, 1993). For example, pyrogenic PAH 
82 

associated with soot in sediments do not partition into the pore water phase and onto pore water 

colloids and so have a low mobility, bioavailability, and toxicity (Readman et al., 1987; 

McGroddy and Farrington, 1995; Maruya et al., 1997). 

3.1.6 57BBiogeochemistry of Arsenic and Mercury in the Coastal Beaufort Sea 

The cANIMIDA Tasks 3 and 4 summer 2005 project included a more detailed investigation of 

As and Hg in the coastal Beaufort Sea. The results of this study are based on Semmler (2006), as 

presented by Trefry et al. (2009). 

3.1.6.1 107BArsenic 

Concentrations of dissolved As were very low (0.03 to 0.17 μg/L) in the Sagavanirktok and 

Kuparuk rivers during the summer of 2005. Concentrations were similar to or lower than 

concentrations reported for other uncontaminated rivers (0.13 to 0.54 μg/L). Worldwide, 

concentrations of dissolved As in rivers vary as a function of drainage basin characteristics 

including geology and climate (Andreae et al., 1983; Andreae and Froelich, 1984) and 

contamination from anthropogenic sources such as mining and industrial effluents (van der Sloot 

et al., 1985). 

Concentrations of dissolved As in the coastal Beaufort Sea (salinity ~ 30 to 32‰) ranged from 

0.8 to 1.4 μg/L during the summer of 2005. These values agree well with concentrations of 0.9 to 

1.3 μg/L previously reported by Trefry et al. (2004b) for the coastal Beaufort Sea, and are within 

the range of typical seawater concentrations. Dissolved As is found at higher concentrations in 

the ocean than in uncontaminated freshwater due to its long residence time of 39,000 years in 

seawater (Broecker and Peng, 1982). 

Concentrations of dissolved As typically increase linearly with increasing salinity across a 

freshwater-seawater mixing zone, although deviations from this behavior have been observed in 

some estuaries, particularly those with anthropogenic sources of As (Andreae et al., 1983; 

Sanders, 1985; van der Sloot et al., 1985; Seyler and Martin, 1990; Yao et al., 2006). 

Concentrations of dissolved As in water samples collected from the mixing zone of the 

Sagavanirktok River during summer 2005 were 8 to 57% lower than the concentrations predicted 

by conservative mixing between river water and seawater end members, suggesting removal of 

As at intermediate salinities (Figure 3-27). 

To determine whether this “missing” dissolved As at intermediate salinities was associated with 

suspended particles, “expected” concentrations of particulate As (Asp) were calculated based on 

the mass ratio of As to Fe in suspended sediments from the Sagavanirktok (Sag) River using the 

following equation: 

Expected Asp (μg/g) = (

p

p

Fe

As

)Sag x Actual Fep(%) 
83 

Figure 3-27. Concentrations of dissolved As versus salinity across the freshwater-seawater 

mixing zone from the Sagavanirktok River to the coastal Beaufort Sea during summer 

2005. The solid line is a conservative mixing line between river water and seawater. 

From Trefry et al. (2009). 

This calculation is based on the assumption that the Sagavanirktok River was the predominant 

source of suspended solids to the mixing zone. The average mass ratio of Asp to particulate Fe 

(Fep) in the Sagavanirktok River during the summers of 2000 to 2002 and 2004 to 2005 

[(

p

p

Fe

As

)Sag] was 2.78 ± 0.46 x 10-4 (n = 9). The expected Asp concentrations were then subtracted 

from the actual Asp concentrations to yield an estimated “excess” As on the particles as follows: 

Excess Asp (μg/L) = Actual Asp (μg/L) – [Expected Asp (μg/g) x TSS (g/L)] 

When values for excess Asp (converted to μg/L), calculated for each sample, were added to the 

corresponding concentrations of dissolved As and plotted as a function of salinity, they provided 

a better fit to the river water and seawater end-members and the conservative mixing line than 

the uncorrected data. This observation suggests that dissolved As was being removed by 

suspended particles across the freshwater-seawater mixing zone by means of biological uptake or 

scavenging of As by suspended sediments. Biological removal of As by phytoplankton seems to 

be of minor importance because the estimated contribution of organic matter to TSS along the 

salinity gradient is < 10% based on concentrations of POC (0.8 to 3.3%), indicating that 

phytoplankton constitute only a small fraction of the suspended matter. Furthermore, 

concentrations of As in phytoplankton collected during this study were low (4.2 ± 2.6 μg/g, n = 

9) compared to concentrations of particulate As in the salinity gradient (18.2 ± 4.3 μg/g, n = 20). 

Colloidal Fe in river water flocculates upon entering the freshwater-seawater mixing zone in an 

estuary, resulting in the precipitation of Fe oxides and oxyhydroxides with coprecipitation of As 

and adsorption to suspended clay (Howard et al., 1984; van der Sloot et al., 1985). This process 

provides a possible removal mechanism for dissolved As across the freshwater-seawater mixing 

zone in this study. 

The distribution of dissolved reactive phosphate (DRP) across the freshwater-seawater interface 

was similar to that observed for dissolved As, and dissolved As correlated strongly with DRP 

Salinity

0 5 10 15 20 25 30

Dissolved As (

g/L)

0.0

0.2

0.4

0.6

0.8

1.0

Dissolved As (nM)

0.0

2.7

5.3

8.0

10.7

13.3
84 

across the salinity gradient. Concentrations of DRP were 3 to 53% lower than the concentrations 

predicted by a conservative mixing line between river water and seawater; however, no 

particulate P data were obtained. One possible conclusion is that DRP may be removed across 

the freshwater-seawater mixing zone by a mechanism similar to that described for dissolved As. 

Phosphate is known to adsorb strongly to and coprecipitate with Fe oxides and oxyhydroxides 

(Feely et al., 1991), suggesting that scavenging or coprecipitation with Fe oxides also was a 

possible mechanism for removal of DRP across the salinity gradient. 

The salinity of surface seawater in Stefansson Sound during July and August 2005 was within 

the range observed at the seaward end of the Sagavanirktok River salinity gradient. However, 

concentrations of dissolved As were higher in coastal seawater than in the mixing zone and were 

highly variable (0.48 to 1.34 μg/L, n = 50), especially at S = 28‰ (0.77 to 1.16 μg L-1, n = 13) 

and S = 32‰ (0.90 to 1.34 μg/L, n = 8). Concentrations of DRP were higher in coastal seawater 

than along the very nearshore salinity gradient; DRP values also were variable, especially at S = 

32 (0.57 to 1.0 μM, n = 7). The variability in concentrations of dissolved As and DRP in 

Stefansson Sound appears to be related to a combination of the following: (1) dilution by sea ice 

meltwater, (2) upwelling of offshore seawater onto the continental shelf, and (3) scavenging by 

or coprecipitation with Fe oxides. Biological uptake by phytoplankton did not appear to be an 

important mechanism controlling concentrations of dissolved As and DRP during this study, as 

discussed later. 

Vertical profiles of dissolved As generally followed those of salinity at water depths ranging 

from about 4 to 12 m, with higher concentrations and greater stratification in the deeper, more 

saline water. However, this trend was not observed in most vertical profiles for DRP or dissolved 

NO3

-

. The dissolved As/DRP ratios at some stations were similar to the value previously reported 

by Feely et al. (1991) for the North Atlantic Ocean (1.5 x 10-2). The similarity of the dissolved 

As to DRP ratios at some locations in nearshore waters of the Beaufort Sea with that of the North 

Atlantic Ocean suggests that offshore seawater that upwells onto the continental shelf of the 

Beaufort Sea may originate in the North Atlantic Ocean. Seawater from the Pacific Ocean enters 

the Beaufort Sea via the Alaskan Coastal Current and flows along the continental slope of the 

Beaufort Sea over deeper water originating from the Atlantic Ocean which contributes to this 

current by upwelling (Weingartner, 2006). The continental shelf receives some input of offshore 

seawater by upwelling (MacDonald et al., 1987; Weingartner, 2006). Thus, the variability in 

concentrations of dissolved As at some locations appears to be controlled, to some extent, by 

upwelling and mixing of offshore seawater with coastal seawater in Stefansson Sound. 

Suspended sediments collected during the summer of 2005 from Stefansson Sound (n = 21) were 

enriched in As and Fe relative to Al (Figure 3-28). Concentrations of Asp (14.5 to 53.0 μg/ g, n = 

21) and Fep (2.4 to 5.9%, n = 21) in most suspended sediment samples plot above the 95% 

prediction intervals established by Trefry et al. (2003) for As versus Al and Fe versus Al in 

bottom sediments collected from the coastal Beaufort Sea during the summers of 1999 through 

2001. These observations support the presence of iron oxides, most likely on clay particles, as 

the source of Fe enrichment. Scavenging of As by iron oxides is the most likely explanation for 

observed As enrichment in suspended particles. Concentrations of As in phytoplankton (4.2 ± 2.6 

μg/g, n = 9) and zooplankton (2.3 ± 1.1 μg/g, n = 9) collected from Stefansson Sound during the 

summer of 2005 were too low to account for the high concentrations of As found in suspended 

sediments. Likewise, resuspension of bottom sediments cannot account for the high 
85 

Figure 3-28. Concentrations of (a) As versus Al and (b) Fe versus Al in total suspended solids 

(TSS) and bottom sediments collected from Stefannsson Sound during the summer of 

2005. Solid lines are from a linear regression and dashed lines are 95% prediction 

intervals for bottom sediments from the coastal Beaufort Sea collected in 1999 

through 2001 (Trefry et al., 2003; n = 194). From Trefry et al. (2009). 

concentrations of Asp because concentrations of As in surficial bottom sediments collected 

during the summer of 2005 (9.8 ± 3.8 μg g-1, n = 38) fit well within the 95% prediction intervals 

of Trefry et al. (2003). Thus, scavenging of As by iron oxides seems to be a common occurrence 

in the study area and a reasonable explanation for the As-rich particles found in the water 

column. 

Concentrations of As in phytoplankton, zooplankton, amphipods, clams, and fish collected 

during summer 2005 are summarized in Table 3-15. Enrichment factors (EF) were determined as 

the ratio of the average concentration of As in tissue (in μg/g dry weight) to the average 

concentration in water (in μg/g of water) or tissue belonging to the next lower tropic level. The 

EF between surface seawater and phytoplankton was ~5,000, indicating that bioaccumulation of 

dissolved As by phytoplankton was occurring. However, this process seemed to have little 

influence on the concentrations of dissolved As in the water column due to the relatively high 

concentrations (1 to 1.5 μg/L) that occur naturally in seawater. No significant differences were 

found for concentrations of As between phytoplankton and zooplankton (t = 1.444, p > 0.05, df = 

16) or between zooplankton and fish (t = 0.451, p > 0.05, df = 27; Figure 3-29). Concentrations 

of As were significantly greater in amphipods than in zooplankton (t = 8.563, p < 0.001, df = 18), 

and also were significantly greater in clams than in phytoplankton (t = 5.770, p < 0.001, df = 11). 

Enrichment factors between successive trophic levels ranged from 0.55 (between phytoplankton 

and zooplankton) to 4.9 (between zooplankton and amphipods). As does seem to biomagnify in 

some steps of marine food webs because inorganic arsenic is converted to arseno-sugars and 

arsenobetaine, probably by sediment bacteria. These organo-arsenic compounds are much more 

bioavailable and slower to be released from tissues than inorganic arsenate and arsenite salts, so 

arsenobetaine, in particular tends to bioaccumulate to high concentrations in marine animals that 

consume benthic fauna (Neff, 1997). Arsenobetaine is not toxic to the consumers. 

Al (%)

0 2 4 6 8 10

As (

g g-1) 0

10

20

30

40

50

60

70

Bottom Sediment

Salinity Gradient TSS

Stefansson Sound TSS

(a)

Al (%)

0 2 4 6 8 10

Fe (%)

0

1

2

3

4

5

6

7

2005 Bottom Sediment

Salinity Gradient TSS

Stefannsson Sound TSS 

(b)
86 

Table 3-15. Concentrations of As in surface seawater (dissolved), phytoplankton, zooplankton, 

amphipods (Anonyx sp.), clams (Astarte sp.) and fish collected from the coastal Beaufort 

Sea during the summer of 2005. From Semmler (2006) and Trefry et al. (2009). 

Sample Type As Concentration (μg/g) 

Mean SD Range N 

Surface seawatera 

(S = 14.5 to 29‰) 0.83x10-3 0.19x10-3 (0.48-1.06) x10-3 14 

Phytoplanktonb,c 4.2 

(6.7) 

2.6 

(4.6) 

0.8 – 7.9 

(1.4 – 15.3) 9 

 Zooplanktonb,c 2.3 

(4.7) 

1.1 

(2.0) 

1.2 - 4.1 

(2.41 – 8.31) 9 

Amphipods (Anonyx sp.) 11.2 3.6 5.0 – 17.4 11 

Clams (Astarte sp.) 13.0 2.2 11.3 – 16.0 4 

Fishd 2.5 1.5 0.8 – 7.4 20 

 a Dissolved concentrations in seawater are in μg/mL

b

Concentrations of phytoplankton and zooplankton are sediment-corrected using ratios to Fe (uncorrected 

concentrations are in parentheses) as described by Semmler (2006). 

c

 Details of phytoplankton and zooplankton species composition are in the Appendix to Task 3-4 

d

 Average of concentrations found in Arctic char, Arctic cisco, Arctic flounder, four-horn sculpin, and 

humpback broad whitefish 

Figure 3-29. Average concentrations of As in phytoplankton, zooplankton, amphipods 

(Anonyx sp.), clams (Astarte sp.) and fish collected from Stefannsson Sound during 

summer 2005. From Trefry et al. (2009). 

Concentrations of As in organisms collected during summer 2005 from Stefansson Sound 

(Table 3-16 and Figure 3-29) compare well with values previously reported by others. For 

example, Lindsay and Sanders (1990) reported an average concentration of 8.6 μg/g in cultured 

phytoplankton exposed to ambient water from the Patuxent River (average concentration of 

dissolved As = 0.71 μg/L). A review by Neff (1997) tabulated average concentrations of As of 

2.1 μg/g (0.2 to 24.4 μg/g, n = 4) in zooplankton, 10.4 μg/g (< 0.6 to 214 μg/g, n = 151) in 

bivalves, and 5.6 (0.05 to 449.5 μg/g, n = 156) in fish. 

Phyto Zoo Amph Clams Fish

As (

g/g)

0

4

8

12

16

20

Phytoplankton

Zooplankton

Amphipods

Clams

Fish
87 

Table 3-16. Concentrations of total dissolved Hg (TDHg) and dissolved CH3Hg+ in selected 

rivers, estuaries and seawater. Beaufort Sea data are highlighted. From Trefry et al. 

(2009). 

Notes: a Filtered using 0.8 μm glass fiber filters; b Filtered using 0.45 μm filters; c Dissolved Hg obtained by 

subtracting particulate Hg (0.02 ± 0.01 ng/g) from total Hg (unfiltered; 0.58 ± 0.34 ng/L); d

 CH3Hg+ reported as total 

CH3Hg+ (unfiltered)

References: (1) Trefry et al., 2009; (2) Coquery et al., 1995; (3) Cossa et al., 1988; (4) Cossa and Noël, 1987; 

(5) Cossa and Martin, 1991; (6) Coquery et al., 1997; (7) Guentzel et al., 1996; 

(8) Trefry et al., 2004b; (9) Mason and Sullivan, 1999; (10) Leermakers et al., 2001; 

(11) Mason and Fitzgerald, 1993; (12) Pongratz and Heumann, 1998. 

Location TDHg (ng/L) Dissolved CH3Hg+ (ng/L) Ref. Mean SD Range Mean SD Range 

Rivers and Estuaries 

Sagavanirktok River 

 (August, 2005, n = 3) 0.81 0.41 0.5- 1.1 < 0.019 - - 1 

Kuparuk River (August 2005, n = 3) 1.03 0.39 0.8- 1.3 < 0.019 - - 1 

Lena Rivera 1.0 0.1 0.9 – 1.1 - - - 2 

Ob Rivera 0.6 0.1 - - - - 2 

Yenisei Rivera 0.3 0.1 - - - - 2 

St. Lawrence Rivera 2.4 0.6 - - - - 3 

Garonne River (Gironde Estuary, 

France)a 3.0 - - - - - 4 

Rhône Rivera 1.6 0.7 0.6 – 2.6 - - - 5 

Loire Rivera 0.82 0.42 0.4 – 2.0 6 

Seine Rivera 2.3 1.9 0.5 – 7.9 6 

Ochlockonee Estuaryb 3.2 1.6 0.7 – 6.0 0.08 - 0.06 – 0.09 7 

Seawater 

Coastal Beaufort Sea (S = 14.5 to 32) 

 August, 2005 (n = 38) 0.69 0.12 0.5 – 0.9 - - < 0.019 – 0.046 1,8 

North Atlantic Ocean (surface)b 0.23 0.20 0.1 – 0.5 - - - 7 

South and Equatorial Atlantic Ocean 

(surface)a,c,d 0.56 - - <0.01 

(MDL) - - 9 

Laptev Sea (Arctic Ocean; S = 32.6, 

depth = 35 m)a 0.80 - - - - - 2 

Kara Sea (Arctic Ocean; S ~34, depth 

= 30-45 m)a 2.0 1.5 0.4 – 3.4 - - - 2 

North Sea and English Channel 

(surface, S ~34-35)d 0.29 0.06 0.2 – 0.4 0.03 0.02 0.02 – 0.06 10 

Equatorial Pacific Ocean (Mixed layer, 

0-100 m)d - - - <0.01 

(MDL) - - 11 

Equatorial Pacific Ocean (>100 m)d - - - - - 

<0.01 

(MDL)- 

116 

11 

Arctic Ocean (75°N, 14°W to 16°E)b - - - - - 

<0.005 

(MDL) – 

0.16 

12 
88 

3.1.6.2 108BMercury 

Concentrations of total dissolved Hg in the Sagavanirktok and Kuparuk rivers during August 

2005 were similar to concentrations reported for other Arctic rivers, including the Lena and Ob 

rivers in Russia, and were ~ 2 to 3 times lower than average concentrations reported for the St. 

Lawrence, Garonne, Rhône, and Seine rivers (Table 3-16). Trefry et al. (2004b) previously 

reported average concentrations of total dissolved Hg of ~ 2 ng/L in the Sagavanirktok, Kuparuk 

and Colville Rivers. Dissolved mono-methylmercury (CH3Hg+

) was not detectable (< 0.019 

ng/L) in the Sagavanirktok and Kuparuk Rivers during low flow conditions in August 2005. 

Concentrations of total dissolved Hg (TDHg) in Stefansson Sound averaged 0.69 ± 0.12 ng/L 

(0.50 to 0.90 ng/L, n = 38, Table 2-6). Trefry et al. (2004b) previously reported concentrations of 

0.70 ± 0.39 ng/L (0.30 to 1.50 ng/L, n = 8) in the coastal Beaufort Sea during August 2000 and 

2001. Concentrations of dissolved CH3Hg+ were undetectable (< 0.019 ng/L) in 12 of the 17 

seawater samples collected during summer 2005. The exceptions included one sample collected 

at station L18 (0.025 ng/L) and four samples collected at station L01C (0.022 to 0.046 ng/L). In 

the 15 samples with concentrations of both TDHg and dissolved CH3Hg+

, CH3Hg+ accounted for 

<3.8 to 7.3% of the TDHg. 

Concentrations of TDHg averaged 1.0 ± 0.2 ng/L (n = 9) across the freshwater-seawater mixing 

zone during the summer of 2005, with no significant trend as a function of salinity (r = 0.14). 

Similar distributions of TDHg were previously observed by Coquery et al. (1995, 1997) in two 

Arctic estuaries, the Ob and the Yenisei, and in the Loire and Seine estuaries, with variable 

concentrations and no clear trend as a function of salinity. The behavior of TDHg in the Loire 

and Seine estuaries was attributed to a combination of several factors, including anthropogenic 

inputs from industrial activities, seasonal variations in water flow, association with colloids, and 

complexation with dissolved organic matter (Coquery et al., 1997). 

Concentrations of TDHg in Stefansson Sound (0.69 ± 0.12 ng/L, n = 38) were significantly lower 

than concentrations of 1.0 ± 0.2 ng/L observed across the freshwater-seawater mixing zone (t = 

6.47, p < 0.001, df = 45). Concentrations of TDHg appear to be controlled by a combination of 

processes including: (1) upwelling of offshore seawater onto the continental shelf, (2) input of 

dissolved Hg to surface waters from organic matter and/or sediment released from melting sea 

ice during summer, and (3) biological productivity. Biological productivity was low during 

summer 2005 and thus it is probably of minor importance in controlling the concentrations of 

total dissolved Hg in Stefansson Sound. However, productivity may play a role in the 

distribution of dissolved CH3Hg+

, as discussed later in this section. The lower concentrations of 

TDHg in coastal seawater relative to the freshwater-seawater mixing zone could be the result of 

upwelling of offshore seawater having lower concentrations of TDHg. Concentrations of TDHg 

in the North Atlantic Ocean (Guentzel et al., 1996) and Northeast Pacific Ocean (Gill and 

Bruland, 1987) are similar and range from ~ 0.1 to 0.5 ng/L and ~ 0.2 to 0.6 ng/L, respectively. 

Thus, mixing of river and intermediate-salinity waters (TDHg = 1.0 ± 0.2 ng/L) with offshore 

seawater originating from the North Atlantic and/or North Pacific Oceans may account for the 

lower concentrations of TDHg found in Stefansson Sound (0.69 ± 0.12 ng/L). 

Vertical profiles of TDHg were relatively uniform with depth at some Beaufort Sea stations and 

increased slightly with depth at some stations in August. Although this distribution does not 

clearly show dilution of dissolved Hg at depth by upwelling of offshore seawater or input of 
89 

dissolved Hg near the surface from melting sea ice, these processes may occur simultaneously 

and compete with each other to produce the observed variability. 

Concentrations of dissolved CH3Hg+ at a station in the Liberty prospect increased from the 

surface (< 0.019 ng/L) to a mid-depth maximum of 0.046 ng/L at 4 m (Figure 3-30). The 

observed distribution of dissolved CH3Hg+

 may be produced by biological activity in Stefansson 

Sound, although the biomass of plankton was estimated to be low (< 600 μg/L) in Stefansson 

Sound during this study. Alternatively, this distribution could be the result of upwelling of 

offshore seawater onto the continental shelf. Pongratz and Heumann (1998) found that 

concentrations of both CH3Hg+

 and (CH3)2Hg were elevated at the boundary of pack ice in the 

Arctic and Antarctic Oceans, corresponding to high biological productivity. In addition, CH3Hg+

is thought to be the main product of decomposition of (CH3)2Hg (Mason and Fitzgerald, 1993; 

Mason et al., 1995b, Pongratz and Heumann, 1998). (CH3)2Hg is produced mainly by anaerobic 

sulfate-reducing bacteria and accumulates in deep ocean waters (particularly the oxygen 

minimum layer (200 to 300 m), over long periods of time (> 5 years) (Mason et al., 1995b). 

Mason et al. (1995) and Mason and Fitzgerald (1993) reported that dimethylmercury,(CH3)2Hg, 

and methylmercury, CH3Hg+, were not found in surface waters of the North Atlantic or 

Equatorial Pacific Oceans, respectively but were detectable in deeper waters below the 

thermocline. 

Figure 3-30. Vertical profiles of (upper left) dissolved CH3Hg+

, (upper right) dissolved As, 

(lower left) dissolved reactive phosphate (DRP), and (lower right) dissolved NO3

-

 in 

seawater at station L01 (Figure 2-3) on August 3, 2005. From Trefry et al. (2009). 

Diss. CH3Hg+ (ng/L)

0.00 0.01 0.02 0.03 0.04 0.05

Depth (m)

0

2

4

6

8

10

12

14 MDL = 0.019 ng L-1

Diss. As (g/L)

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Depth (m)

0

2

4

6

8

10

12

14

DRP (M)

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Depth (m)

0

2

4

6

8

10

12

14

Diss. NO3

-

 (M)

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Depth (m)

0

2

4

6

8

10

12

14
90 

Concentrations in deep waters ranged from < 0.002 (MDL) to 0.07 ng/L for (CH3)2Hg and were 

at or below the MDL (0.01 ng/L) for CH3Hg+

 in unfiltered samples from the North Atlantic 

Ocean (Mason et al., 1995). Values ranged from 0.008 to 0.15 ng/L for (CH3)2Hg and < 0.01 

(MDL) to 125 ng/L for CH3Hg+

 in unfiltered samples from the Equatorial Pacific Ocean (Mason 

and Fitzgerald, 1993). Pongratz and Heumann (1998) reported concentrations of dissolved (< 

0.45 μm) CH3Hg+

 and (CH3)2Hg of ~ 0.1 to 3 ng/L in surface waters of the North Atlantic (40 to 

51° N, 10° W), adjacent to areas of anthropogenic inputs. Thus, upwelling of seawater 

originating from the deeper waters of the Atlantic or Pacific Oceans and/or influenced by higher 

concentrations within the region of the pack ice boundary may be a source of CH3Hg+

 to the 

coastal waters of Stefansson Sound. This hypothesis is supported by the observation that 

concentrations of dissolved As, DRP, and dissolved NO3

-

 also were highest at intermediate 

depths and at stations located farthest offshore in Stefansson Sound (Figure 3-30). The 

methylmercury in Beaufort Sea coastal water probably is from upwelling offshore near the edge 

of the pack ice (Semmler, 2003) and from runoff from melting permafrost soils containing a 

large inventory of mercury and methylmercury from aerial deposition and methylation in suboxic 

layers of frozen soil (MacDonald et al., 2005, 2009). 

There is particular concern about mercury in Arctic marine food webs (MacDonald et al., 2005; 

Jaeger et al., 2007). Mercury concentrations in marine waters in much of the Arctic are higher 

than concentrations in temperate and tropical waters due in large part to upwelling of Hg at the 

ice edge and deposition of metallic and inorganic mercury from long-range transport and 

deposition from the atmosphere (Skov et al., 2004; MacDonald et al., 2005; Outridge et al., 

2008; Sommar et al., 2010). Concentrations of TDHg are high in the upper water column and 

overlying atmosphere of the Alaskan and Canadian Arctic during ice-covered periods (Sommar 

et al., 2010). The net flux of Hg during this time seems to be from the water to the atmosphere. 

TDHg concentrations in surface waters usually are much lower in ice-free conditions. There is 

no evidence that mercury in the Beaufort Sea is coming from onshore or offshore oil and gas 

operations (Neff, 2010). 

Concentrations of total Hg were significantly higher (EF = 2.7) in clams than in phytoplankton (t 

= 2.84, p < 0.05, df = 8) and also were significantly higher (EF = 1.9) in fish than in zooplankton 

(t = 2.13, p < 0.05, df = 26; Table 3-17 and Figure 3-31). No significant difference was found for 

concentrations of total Hg between zooplankton and amphipods (t = 1.63, p > 0.05, df = 16; 

Table 3-17 and Figure 3-31). 

Concentrations of total Hg in zooplankton collected from Stefansson Sound during summer 2005 

compare well with concentrations found by Stern and MacDonald (2005) in zooplankton 

(Calanus hyperboreus) from the Canadian Basin of the Beaufort Sea (85 ± 9 ng/g) and from the 

Chukchi Plateau and Mendeleev Basin of the Arctic Ocean (48 ± 3 ng/g). Stern and MacDonald 

(2005) also reported concentrations of CH3Hg+

 in C. hyperboreus of ~ 5 to 20 ng/g (~ 10 to 30% 

of the total Hg), slightly higher than concentrations found during this study. Atwell et al. (1998) 

also determined concentrations of total Hg in zooplankton (C. hyperboreus) from Lancaster 

 
91 

Table 3-17. Concentrations of mercury and methylmercury in surface seawater (dissolved), 

mixed phytoplankton, mixed zooplankton, amphipods (Anonyx sp.), clams (Astarte sp.), 

and fish (average for Arctic char, Arctic cisco, Arctic flounder, fourhorn sculpin, and 

humpback broad whitefish from the coastal Beaufort Sea. From Semmler (2006) as 

presented by Neff (2010). 

Sample Type Concentration (ng/g dry wt: ppb)a Bioconcentration 

Factorb Mean SD Range N 

Total Mercury 

Surface seawaterc 0.69 ± 0.12 0.50 - 0.90 38 - 

Phytoplankton 19.6 ± 13.4 11.2 - 39.7 4 28,400 

Zooplankton 55.4 ± 30.7 29.6 - 105 8 2.8 

Amphipods 78.0 ± 28.2 46.4 - 117 8 1.4 

Clams 53.5 ± 18.4 42.6 - 80.9 4 2.7 

Fish 106.2± 64.2 30.0 - 266 20 1.9 

Methylmercury 

Surface seawaterc 0.025 ± 0.01d <0.02 - 0.046 15 - 

Phytoplankton 0.60 ± 0.56 0.22 - 1.24 3 24,000 

Zooplankton 4.25 ± 1.94 2.21 - 6.66 6 7.1 

a

 Concentrations of dissolved total mercury and methylmercury in seawater are ng/L (parts per trillion); b

Bioconcentration factor is the concentration in consumer divided by the concentration in prey (or water for 

phytoplankton); c

 Salinity varied from 14.5 to 32‰; d Average and SD were determined using the method detection 

limit (MDL) as the concentration for samples in which methylmercury was not detected above the MDL. 

Sound, Northwest Territories, Canada, and found a similar average concentration of 60 ± 10 

ng/g. Campbell et al. (2005) reported similar concentrations of total mercury in mixed 

zooplankton from the Northwater Polynya in Baffin Bay, Canada, to those reported by Dehn et 

al. (2005) for the Alaskan and Canadian Arctic (5 to 50 ng/g). Earlier, Joiris et al. (1997) 

reported that concentrations of total mercury were lower in zooplankton from the Barents Sea 

(90 to 120 ng/g) than in those from the North Sea (mean, 320 ng/g). Jaeger et al. (2007) did not 

detect mercury in copepods and euphausiids (Meganychtophanes norvegica, Thyasoessa inermis, 

Thermisto libellula, and Calanus hyperboreus) from the Barents Sea. These zooplankton are the 

main foods of bowhead whales in the Canadian and Alaskan Arctic. 

Concentrations of total Hg in Astarte sp. clams collected from Stefansson Sound during this 

study (53 ± 18 ng/g) were similar to concentrations of total Hg of 70 ± 10 ng/g reported by 

Atwell et al. (1998) in Mya truncata (a filter-feeding clam) from Lancaster Sound. Stern and 

MacDonald (2005) reported concentrations of total Hg in Arctic cod (Boreogadus saida) from 

the Canadian Basin of the Beaufort Sea (270 ± 40 ng/g) and from the Chukchi Plateau and 

Mendeleev Basin (85 ± 5 ng/g), adjusted for variability in δ15N and body length. Atwell et al. 

(1998) reported similar concentrations of total Hg in muscle of Arctic cod (190 ± 30 ng/g) from 

Lancaster Sound. Bloom (1992) reported concentrations of total Hg and CH3Hg of 200 ng/g 

(100% of total Hg was CH3Hg) in Chinook Salmon (Oncorhynchus tshawytscha) muscle and 

780 and 740 ng/g (95% of total Hg was CH3Hg) in lingcod (Ophiodon elongatus) from southeast 

Alaska. These concentrations of total Hg and CH3Hg in various species of fish are similar to or 

slightly higher than those found in fish collected from Stefansson Sound during summer 2005. 
92 

Figure 3-31. Concentrations of total Hg and CH3Hg+ in phytoplankton and zooplankton (top) 

and total Hg in phytoplankton, zooplankton, amphipods, clams, and fish (bottom) 

collected from Stefansson Sound during summer 2005. From Trefry et al. (2009). 

Because CH3Hg+

 tends to biomagnify in marine food webs, concentrations of total and 

methylmercury may be high in high trophic level consumers in Arctic seas, such as marine 

mammals and birds. Concentrations of total and methylmercury are high in liver and muscle 

tissues of several marine mammals collected off Barrow, AK (Table 3-18). Fish and mammal 

eating marine carnivores, such as polar bears, beluga whales, and some seals, contain high 

concentrations of total and methylmercury in liver, with lower concentrations in muscle and 

other organs. Bowhead whales do not bioaccumulate high concentrations of mercury because 

they feed at a lower trophic level on large copepods and euphausiids, which contain low 

concentrations of methylmercury. Most of the mercury in liver is complexed with selenium to 

form relatively inert concretions. Most of the mercury in muscle is highly toxic methylmercury 

(Neff, 2010). 

 

Phytoplankton Zooplankton

Concentration (ng/g)

0

20

40

60

80

100

Total Hg

CH3Hg+

 Phyto. Zoo. Amph. Clams Fish

Total Hg (ng/g)

0

50

100

150

200
93 

Table 3-18. Concentrations of total mercury and methyl mercury in muscle and liver of marine 

mammals collected off Barrow, Alaska. Concentrations are ng/g dry wt, converted from 

wet weight by multiplying by 5. From Dehn et al. (2005, 2006a,b). 

Species Tissue Total Mercury Methyl Mercury 

Polar Bear Ursa maritimus Liver 7500 - 272,000 No data 

Ringed Seal Pussa hispida

Muscle 50 - 53,000 50 - 1900 

Liver 300 - 82,500 50 - 2500 

Beluga Whale Delphinapterus leucus

Muscle 650 - 61,500 650 - 12,000 

Liver 1400 - 362,000 950 - 19,400 

Bowhead Whale Balaena mysticetus

Muscle <5 - 50 No Data 

Liver 5 - 3000 No Data 

3.2 13BCharacterization of Metals and Hydrocarbons in Sediments in the 

ANIMIDA/cANIMIDA Study Area 

A large number of stations in the Northstar, Liberty, and BSMP areas were sampled in 2004, 

2005, and 2006 for analysis of metals and hydrocarbons in surficial and core sediments (Table 2-

1, Figure 2-3) (Brown et al., 2010). Many of these stations had been sampled one or more times 

in 1999 through 2002 for analysis of sediment metals and hydrocarbons as part of the Phase 1 

and 2 ANIMIDA Project (Boehm et al., 2001; Brown et al., 2004). The objective of this 

sampling was to better characterize the range of concentrations of several metals and three 

hydrocarbon classes (SHC, PAH, and StTr) in sediments of the oil and gas development area in 

the Alaskan Beaufort Sea and to determine if there where changes in physical and chemical 

properties of the sediments that could be linked to exploration and development activities. 

3.2.1 58BSediment Grain Size and Concentrations of Total Organic Carbon (TOC), and 

Metals 

3.2.1.1 109BTotal Organic Carbon 

TOC concentrations in surficial sediments ranged from 0.02% in sandy sediment in shallow 

water (1.8 m) at station L21 near the mouth of the Sagavanirktok River to 6.4% in a peat-bearing 

sample from station N14 (Table 3-19). The overall mean concentration of TOC of 0.77 ± 0.77% 

for 2004-2006 was not significantly different (p<0.01) from the means from 1999-2002 of 0.91 ± 

0.86%. There was considerable patchiness in TOC concentrations across the study area, probably 

related to the patchiness in the occurrence of fine-grained sediment. The mean and range of TOC 

concentrations was similar in the Northstar, Liberty, and BSMP areas in 2004-2006 (Table 3-19). 

Overall, the TOC concentrations are typical of values reported by others for the nearshore 

Beaufort Sea. For example, Carsola (1954) reported a range of TOC values from 0.2-1.2 % for 

Beaufort Sea sediments. 

 
94 

Table 3-19. Mean and range of concentrations of Al, Fe, TOC, and % silt + clay (mud), in 

sediments from the Northstar, Liberty, and BSMP areas, 2000 - 2006. Al and Fe 

concentrations in sediments are useful for normalization of other metals concentrations to 

the sediment clay fraction. All concentrations are % dry wt. (Data from Brown et al., 

2005, 2009). 

Metal Year Northstar Liberty BSMP 

Aluminum (Al) 

2000 4.23 (0 - 6.76) 3.98 (0 - 6.76) 3.65 (1.26 - 6.98) 

2002 4.49 (1.65 - 5.92) 3.41 (1.56 - 5.42) 2.95 (1.65 - 4.38) 

2004 4.13 (1.64 - 6.32) 4.16 (2.17 - 5.83) 3.24 (1.28 - 5.84) 

2005 3.19 (1.91 - 4.89) 4.36 (2.17 - 6.30) 3.46 (1.89 - 5.52) 

2006 4.43 (1.78 - 5.79) 3.17 (2.04 - 4.01) 4.06 (2.69 - 6.29) 

Iron (Fe) 

2000 2.38 (0 - 3.66) 2.25 (0 - 3.66) 2.23 (0.92 - 3.91) 

2002 2.52 (0.89 - 3.29) 1.95 (0.99 - 2.82) 1.76 (0.78 - 3.03) 

2004 2.42 (0.94 - 3.70) 2.47 (1.33 - 3.39) 1.96 (0.95 - 3.11) 

2005 2.06 (1.34 - 2.78) 2.34 (1.25 - 3.43) 1.90 (0.97 - 2.77) 

2006 2.74 (1.27 - 3.65) 2.11 (1.12 - 2.76) 2.57 (1.54 - 3.70) 

Total Organic Carbon 

(TOC) (%) 

2004 0.56 (0.04 - 1.72) 0.95 (0.25 - 2.38) 0.47 (0.04 - 0.91) 

2005 1.71 (0.11 - 6.42) 0.77 (0.28 - 1.60) 0.66 (0.05 - 1.75) 

2006 1.00 (0.23 - 1.38) 0.85 (0.02 - 2.75) 0.95 (0.08 - 2.17) 

Silt + Clay (Mud) (%) 

2004 45.6 56.0 44.5 

2005 29.4 58.4 35.6 

2006 66.7 39.6 49.0 

3.2.1.2 10BSediment Grain Size 

The grain size distribution also was variable throughout the study area and from one year to the 

next. Gravel concentration (>2 mm) ranged from 0% in 68 of 112 surface sediment samples to 

61% at station N15, located adjacent to Stump Island and 46% at the pipeline just south of 

Northstar Island. Likewise, mean silt + clay (mud) concentrations in surface sediments from the 

three study areas were variable, ranging from 29.4% at Northstar in 2005 to 66.7% at Northstar 

in 2006 (Table 3-19). The highest clay concentration in sediments sampled in the 1999-2002 

ANIMIDA Project was 50% at station 4A in the BSMP area. Sediment resuspension, along with 

across and along shelf transport, are dynamic components of the inner shelf of the Beaufort Sea 

that certainly contribute to observed variations in grain size distribution in the top 1 cm of 

nearshore Beaufort Sea sediments, as discussed above. 

The mean % mud in sediments from all stations combined was 47%, 40%, and 50%, in 2004, 

2005, and 2006, respectively. Mean sediment mud concentrations were higher at Liberty stations 

in 2004 and 2005, and at Northstar stations in 2006 (Table 3-19). Thus, although sediment grain 

size was variable throughout the development area, the mean and range of concentrations of mud 

were similar in all years, and compared favorably with data from 1999 and 2002. 
95 

Inter-annual shifts in the texture of surficial sediments have occurred throughout the cANIMIDA 

study area. Large changes in grain size distribution were observed first in the ANIMIDA Project 

between 1999 and 2000. For example, during 1999, surficial sediment at four Northstar stations 

was essentially all sand and gravel. In 2000, sediment samples from these same stations 

contained mainly silt and clay. Although the exact mechanism for this shift is not known, the 

1999 samples were collected after a 6-day storm with winds in excess of 25 knots that may have 

eroded away finer-grained material. No such storms preceded collection of the 2000 samples 

that probably contained finer-grained material carried in by the Kuparuk River during the spring 

breakup of 2000. The opposite shift occurred at two stations close to the Northstar Island where 

fine-grained sediments were more abundant in samples collected in 1999 than in 2000. This shift 

may have resulted from inputs of coarser material at these stations in association with 

construction of the island. Grain size distribution at the other Northstar stations was similar for 

1999 and 2000. 

An important observation from the grain size data is that sediments in many locations throughout 

the cANIMIDA study area are regularly shifting and that the sediment grain sizes found during 

one year may change prior to sampling during a subsequent year. Furthermore, the grain size 

distribution in surface sediments is very patchy from site to site. Thus, techniques that normalize 

sediment chemistry to account for differences in grain size should be used to determine if 

surface and subsurface sediment collected during any given year is recent and not relict material, 

and to determine if sediment metals and hydrocarbons are natural or from human activities. 

3.2.1.3 1BGeochronology of Surficial Beaufort Sea Sediments, Based on 210Pb and 137Cs 

Activity 

The cANIMIDA study area has been a net erosional sedimentary environment during the past 

several thousand years (Reimnitz and Barnes, 1974). At best, sediment deposition in the 

cANIMIDA area has been patchy during the past century. Trefry et al. (2003) cautioned 

investigators to be sure that sediments collected for analysis of potential contaminants are 

representative of the most recent inputs. Surficial sediments from the 2004-2006 surveys were 

counted for the activities of excess 210Pb and total 137Cs to determine the extent of possible 

sediment deposition or erosion in the area. The pre-survey assumption was that surface 

sediments with low activities of excess 210Pb (<0.5 dpm/g) or 137Cs (<0.05 dpm/g) would contain 

very little silt or clay that had been recently or sufficiently well exposed to the water column or 

at the sediment-seawater interface to adsorb excess 210Pb or 137Cs. Therefore, such sediments 

would be less likely to contain recent material that had an anthropogenic contribution of metals 

or hydrocarbons. However, in some cases, sediments with low excess 210Pb and 137Cs activities 

might be predominantly sand that had a naturally low affinity for these isotopes. Sediments that 

have intermediate levels of the two isotopes may be sandy or contain some mixture of old, recent 

and sandy sediments. 

During each of the three years of this study, surface sediments were found with non-detectable 

amounts of excess 210Pb (<0.05 dpm/g) and 137Cs (<0.015 dpm/g) at some locations. In contrast, 

maximum values for excess 210Pb of 2.8 dpm/g and 137Cs of 0.20 dpm/g were observed at other 

locations. Collectively, the activities for 226Ra (parent isotope to 210Pb) correlated well with 

concentrations of Al. This good relationship is consistent with higher amounts of 226Ra in Al-rich 

clays. However, there is another 226Ra-bearing phase in many of the sediments, possibly 

associated with natural barite in fine-grained sediments. 
96 

There is considerable scatter in the relationship between Al and excess 210Pb in surface 

sediments. One explanation for the observed scatter is large differences in the accumulation rates 

and/or ages among the 112 samples of surface sediment. Samples with low amounts of excess 

210Pb (<0.5 dpm/g) and Al concentrations >3% are less likely to contain very much recent 

sediment relative to samples with excess 210Pb >0.5 dpm/g and Al concentrations >3%. A weak, 

but observable trend of higher activity for excess 210Pb in sediments with a higher activity of 

137Cs than was observed for the surface sediments is consistent with increased adsorption of the 

two isotopes from water by clay-rich (i.e., Al-rich) sediments. 

Weiss and Naidu (1986) used vertical profiles for the activity of total 210Pb to calculate 

sedimentation rates of 0.6 to 1 cm/year at sites in Simpson Lagoon, near our stations 6A and 6G; 

however, the total activities for 210Pb averaged <2 dpm/g with variable texture in each core. 

Naidu et al. (2001) more recently reported no excess 210Pb and no detectable 137Cs in a core from 

Simpson Lagoon. However, they reported excess 210Pb levels of 0.9 to 1.2 dpm/g and 137Cs 

activities of 0.2 dpm/g at a site near station 3B. Based on inherent difficulties with area 

sediments, a primary goal of our geochronology effort was to collect some sediment that was 

deposited prior to the onset of onshore development during the late 1960s and some sediment 

that was deposited post-development. 

Our results show sedimentation rates that range from ~0.04 cm/year to ~0.10 cm/year, with 

several sites having little or no net accumulation of sediment during at least the past 50 years. At 

three sites, we identified 3- to 5-cm thick layers of sediment that were deposited since onshore 

development began (approximately 1970). Our overall results are consistent with those of Naidu 

et al. (2001) for the same area. We know from our previous work that the presence of finegrained sediment at a given location can vary from year to year and that the sediments along 

much of the shallow, coastal Beaufort Sea are quite dynamic. 

Additional support for low sedimentation rates at stations P01 and E01 can be developed from 

data for river inputs of sediment. The Sagavanirktok River, the major river carrying sediment 

into this area, is estimated to have an annual sediment load of about 330,000 metric tons 

(Rember and Trefry, 2004). The depositional area for this sediment in coastal Beaufort Sea is 

about 1000 km2 (the approximate area bounded by the mainland to the south, the outer islands 

such as Cross Island to the north, and between 147.0° N and 148.5° W) to yield an estimated 

deposition rate of ~0.04 cm/year based on a sediment bulk density of 1.6 g/cm3

 ([0.6 x 1012 g dry 

sediment/10 x 1012

 cm

2

] x [(1.6 g wet sediment/cm3)/(2.6 g dry sediment/cm3)]). As previously 

noted, however, the coastal Beaufort Sea in this area may be net erosional at this time (Reimnitz 

and Wolf, 1998). 

Despite difficulties in determining sedimentation rates, we now have sediment samples that we 

know pre-date and post-date development. We also have surface sediments from 1989, 1999, 

2000, and 2002 cores that can be used to evaluate any recent trends in deposition of potential 

contaminants. 

3.2.1.4 12BAluminum (Al) and Iron (Fe) in Sediments 

Concentrations of aluminum (Al) and iron (Fe) usually are high (percent levels) in marine 

sediments. Most of the Al in marine sediments is in clays (aluminosilicates). The iron in oxidized 

layers of sediments is present primarily as minute, insoluble iron oxyhydroxide layers on clay 
97 

particles. Thus, Al and Fe concentrations can be used to normalize metals concentrations to the 

fine, clay fraction of sediments. Iron is less reliable for this purpose because solid Fe in 

sediments varies with sediment redox potential. Mean concentrations of Al in surficial sediments 

were 3.8% in 2004, 3.6% in 2005 and 3.8% in 2006, relative to 3.6% in 1999, 4.1% in 2000, and 

3.8% in 2002 for sediments from all stations combined. Mean concentrations of Al and Fe were 

similar in sediments from Northstar, Liberty, and BSMP in all years (Table 3-19). Although 

mean concentrations of TOC, silt + clay, Fe and Al in surficial sediments were similar from year 

to year, the standard deviations within a given year were large. Therefore, no significant 

differences in mean concentrations of TOC, silt + clay, or Al have been observed among years 

from 1999 to 2006. 

3.2.1.5 13BMetals in Surficial Sediments 

All surficial sediments, (top 1 cm) were analyzed for concentrations of total Ag, Al, As, Ba, Be, 

Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Se, Sn, Tl, V and Zn. There was considerable patchiness in 

the concentrations of all metals in surficial sediments. Sediment metals concentrations vary in 

response to variations in sediment source, mineralogy, grain size, TOC, and redox potential. As 

discussed above, Arctic rivers discharge massive amounts of suspended sediments each spring to 

the nearshore Alaskan and Canadian Beaufort Sea. Clay sediments tend to contain higher 

concentrations of most metals than quartz or carbonate sediments do. Sediment 

oxidation/reduction (redox) potential affects speciation and, therefore, solubility of many metals, 

particularly iron and manganese, which are important adsorptive phases in oxidized sediment 

layers (Neff, 2002a). The highest concentrations of metals were in Al-rich (>6% Al) sediments 

from stations N03, N17, L06, L07, and 7C. The lowest metal concentrations were found in sandy 

sediments. However, concentrations of Fe, Zn, Cu, Cr and Ni were slightly elevated in the 

gravel-rich, Al-poor sediment from the top of the pipeline (station N23), sampled in 2004. The 

maximum concentrations were within the normal range for Arctic marine sediments. 

Concentrations of eight metals, of the types that are of concern in marine sediments because of 

their toxicity or association with offshore oil and gas development activities (Neff, 2010), in 

surface sediments in the Northstar, Liberty, and BSMP areas are summarized in Tables 3-20 and 

3-21. Mean concentrations of all eight metals were roughly similar in sediments in the three 

areas in all years sampled between 2000 and 2006. None of the metals was consistently present 

at a higher range of concentrations in sediments from the Northstar production facility, than in 

sediments from the Liberty prospect or the historic BSMP stations. There also were no temporal 

trends in concentrations of any of the metals in sediments from the three areas. 

Concentrations of metals in Beaufort sea sediments have been monitored frequently during the 

last three decades as part of MMS and oil industry monitoring projects. Tables 3-22 and 3-23 

summarize sediment metals data collected between 1984 and 2008 at a large number of locations 

throughout the Beaufort Sea. Most samples were collected distant, in time and space, from 

exploratory drilling activities, so the concentrations can be considered to represent the natural 

background. 

Grain size distribution and concentrations of TOC and trace metals are variable in sediments in 

coastal and offshore waters of the western Beaufort Sea. Trefry et al. (2003) reported that nearly 

all samples of surface sediments and age-dated cores contain natural concentrations of several 

metals, with metal/Al ratios that have been constant for many decades. Metal concentrations in 
98 

river-suspended matter entering the Beaufort Sea in spring runoff compare well with metal 

concentrations in coastal and offshore sediments. Overall, the constancy of metal/Al ratios in 

river-suspended sediment, the surface layers of bottom sediments, and deeper, older layers in 

bottom sediments show that anthropogenic inputs of trace metals have not significantly elevated 

metals concentrations in sediments in areas of offshore oil exploration and production in the 

coastal Beaufort Sea. 

Concentration ranges of metals in WBM used and discharged offshore in the Beaufort Sea 

between 1979 and 1982 are also included in Tables 3-22 and 3-23 for comparison. The only 

metals in historic Beaufort Sea WBM that sometimes are present at higher concentrations than 

those in Beaufort Sea sediments are barium, chromium, lead, and zinc. There are no area-wide 

trends in concentrations of these or the other metals that might be associated with ocean 

discharges of WBM and cuttings from more than 50 Beaufort Sea exploration, delineation, and 

development wells. Concentrations of barium, chromium, copper, and lead in some samples 

collected near the historic Hammerhead exploratory drilling site, drilled in 1985/6, were higher 

than metals concentrations elsewhere in the Camden Bay area. Concentrations of these four 

metals were slightly elevated over a small area at the drill site. There was no evidence of spread 

of metals over a larger area of sediments in the 24 years since drilling. Thus, the concentrations 

of sediment metals summarized in Tables 3-22 and 3-23 can be used as background 

concentrations for comparison with metals in sediments at Northstar and future exploration and 

development sites. 

Concentrations of trace metals generally correlate well with concentrations of Al because 

concentrations of both Al and most metals are very low in quartz sand or carbonate shell material 

and much higher in fine-grained aluminosilicates. Aluminum is rarely introduced by 

anthropogenic activities and is present at percent levels in most sediments relative to part per 

million (ppm) levels for trace metals. Thus, for this study, Al provided a valuable normalization 

tool that incorporated the metal controlling variables of grain size, organic carbon content and 

mineralogy. In the ideal case, there is a good linear correlation between concentrations of a trace 

metal and Al in sediment. Significant, positive deviations from this linear trend, can be used to 

identify possible metal contamination of sediments. Plots of trace metal concentrations versus Al 

have been used in various forms for many years to identify sediment metal contamination (e.g., 

Bruland et al., 1974; Trefry et al., 1985; Schropp et al., 1990). 

Trefry et al. (2003) used metal data for surface sediments collected in 1999-2002 from the 

coastal Beaufort Sea to produce a series of metal/Al plots that were used in the ANIMIDA and 

cANIMIDA Projects as templates for identifying possible metal contamination or deviations 

from previous observations. A linear regression and a 99% prediction interval were calculated 

for each of the metal versus Al plots using the 1999-2002 data. Metal/Al concentration ratios for 

all metals in all sediment samples were compared to values predicted from the regressions. 

Metal/Al ratios lying above the 99% prediction interval for the model regression were considered 

to possibly contain excess metal from anthropogenic sources. 

Few large anomalies in metal concentrations, based on the metal/Al regressions, or unusually 

high sediment metal concentrations were observed during this study. However, 44 of 1792 metal 

concentrations (~2.5% of the data points) in surface sediments plotted slightly above the upper 

prediction intervals on the respective metal versus Al graphs. Eleven of these anomalies are 

believed to be due to the presence of a trace amount of natural metal sulfide minerals in anoxic 
99 

sediment layers. A total of about 17 minor anomalies on the metal versus Al graphs (0.9% of 

data points) were identified in the cANIMIDA area. 

Metal/Al regressions for the four metals most often associated with offshore exploration and 

development, Ba, Cr, Pb, and Zn is sediments from the development area of the Beaufort Sea 

revealed only a small number of sediment metals concentrations above expected values. 

Figure 3-32 shows the regressions plots for Ba/Al and Cr/Al. Ba concentration was elevated 

above expected values at Northstar station N06 and at BSMP stations 6H, 7G, and 7A. 

Chromium concentrations were elevated at Northstar station N03, Liberty station L22, and 

BSMP stations 6H and 7A, and at the West Dock. All the elevated concentrations for Ba and Cr 

were in samples collected in 2006, except Ba in N06 sediment that was elevated in 2005. All the 

BSMP stations were in Harrison Bay or off the Colville River. West Dock is the main supply 

dock for Prudhoe Bay. 

Barium has been used historically as a sensitive indicator for the presence of drilling muds and 

cuttings in sediment because insoluble barite (BaSO4) usually is the most abundant solid 

ingredient in drilling muds (Neff, 2010). Concentrations of Ba in surface sediments in the 

development area ranged from 16 mg/kg to 910 mg/kg between 2000 and 2006, with little 

difference in sediment Ba concentration in Northstar, Liberty, and BSMP sediments 

(Table 3-20). This range of Ba concentration is typical for uncontaminated fine-grained marine 

sediments (Neff, 2010). The graph for Al versus Ba for the 2004-2006 data shows 4 of 112 data 

points as positive anomalies on the Ba versus Al plot (Figure 3-32a). Barium anomalies were 

reported previously for stations 7A and 7G by Trefry et al. (2003) for samples collected in 1989 

and are consistent with exploratory drilling in sediments in the area (Crecelius et al., 1991). 

Barium anomalies at stations N06 and 6H also may be due to minor remnants of drilling 

discharges. The largest observed anomaly of 549 μg/g at 2006 station 5H [anomaly = 863 μg/g – 

(2.73% Al (72.9) + 115) = 549 μg/g] is equivalent to a residue of 0.1% barite from drilling mud 

with 53% Ba (Trefry et al., 2007). 

A plot of Al versus Cr from the ANIMIDA Project (Figure 3-32b) shows the strong positive 

relationship observed for the 2004 - 2006 data. The good linear fit for Al versus Cr is consistent 

with mixing of relatively uniform composition, metal-rich aluminosilicate (clay) phases with 

metal-poor sand and shell. Chromium concentrations in sediment from the ANIMIDA study 

ranged from 15 to 116 mg/kg in 2000 to 2006 (Table 3-20). Sediments from five stations 

sampled during 2006 had Cr concentrations that plotted above the upper 99% prediction interval 

(Figure 3-32), with a maximum total Cr concentration among these five stations of 89 μg/g. 

Concentrations of Cr were previously reported to be elevated at station 7A in Harrison Bay 

(Boehm et al., 1990; Trefry et al., 2003). Crecelius et al. (1991) reported elevated levels of Cr in 

eastern Harrison Bay (BSMP stations 7A, 7B and 7G) and western Camden Bay (BSMP station 

2E) with a maximum total Cr value in that study also at 89 μg/g. The main source of Cr in 

sediments near drill sites sometimes is chrome lignosulfonate, used in the past in water based 

drilling muds. This additive is no longer used in drilling muds (Neff, 2010). Thus, the 2006 Cr 

anomalies may be from historic drilling discharges or from other sources, such as suspended 

sediments from Arctic rivers. 
100 

Table 3-20. Mean and range of concentrations of As, Ba, Cd, Cr, and Cu, all metals of concern 

during offshore oil and gas development, in sediments from the Northstar, Liberty, and 

BSMP areas, 2000 - 2006. Metals concentrations are mg/kg dry wt (parts per million). 

Data from Brown et al. (2005, 2010). 

Metal Year Northstar Liberty BSMP 

Arsenic (As) 

2000 9.93 (0 - 15.4) 9.81 (0 - 17.9) 8.73 (5.2 - 15.6) 

2002 10.4 (4.2 - 14.3) 8.71 (4.3 - 13.7) 8.13 (4.5 - 13.0) 

2004 10.7 (17.5 - 22.0) 11.5 (6.7 - 18.6) 9.0 (5.3 - 14.3) 

2005 12.8 (7.6 - 24.9) 11.3 (4.7 - 20.3) 8.9 (4.9 - 13.5) 

2006 11.2 (5.5 - 15.0) 9.0 (5.8 - 13.0) 11.9 (6.9 - 22.8) 

Barium (Ba) 

2000 428 (0 - 859) 399 (0 - 859) 391 (164 - 912) 

2002 467 (212 - 584) 387 (165 - 538) 348 (203 - 589) 

2004 462 (254 - 654) 441 (221 - 612) 323 (16 - 668) 

2005 469 (299 - 749) 506 (259 - 701) 389 (198 - 620) 

2006 486 (256 - 626) 378 (229 - 575) 515 (307 - 863) 

Cadmium (Cd) 

2000 0.24 (0 - 0.45) 0.22 (0 - 0.45) 0.21 (0.03 - 0.33) 

2002 0.17 (0.05 - 0.27) 0.16 (0.05 - 0.31) 0.19 (0.06 - 0.59) 

2004 0.17 (0.04 - 0.31) 0.18 (0.05 - 0.36) 0.14 (0.03 - 0.23) 

2005 0.29 (0.09 - 0.77) 0.22 (0.11 - 0.38) 0.15 (0.04 - 0.43) 

2006 0.23 (0.09 - 0.30) 0.21 (0.04 - 0.39) 0.20 (0.10 - 0.46) 

Chromium (Cr) 

2000 63.1 (0 - 92) 59.1 (0 - 92) 57.8 (16.6 - 116) 

2002 65.1 (22.4 - 83.4) 50.8 (19.7 - 72.8) 46.6 (19.2 - 67.4) 

2004 67.6 (20.2 - 97.1) 66.6 (32.3 - 95.3) 50.0 (14.7 - 81.1) 

2005 56.5 (43.8 - 79.4) 67.8 (37.3 - 96.2) 49.6 (17.2 - 75.2) 

2006 74.9 (33.4 - 95.4) 60.0 (26.9 - 80.6) 71.1 (40.9 - 99.6) 

Copper (Cu) 

2000 21.1 (0 - 40) 20.0 (0 - 40) 18.7 (3.6 - 37) 

2002 19.2 (5.4 - 26.3) 13.6 (4.2 - 22.1) 14.6 (4.3 -- 34.1) 

2004 19.4 (4.4 - 32.2) 20.9 (7.6 - 38.4) 14.9 (4.9 - 24.1) 

2005 21.5 (8.3 - 46.2) 21.5 (8.8 - 40.6) 14.4 (3.9 - 24.7) 

2006 21.7 (7.5 - 31.9) 15.8 (5.8 - 25.5) 18.0 (9.2 - 30.4) 

There were only a few elevated Pb and Zn concentrations in sediments, based on 

metal/Aluminum concentration plots. In all cases, the concentrations of Pb and Zn were in the 

range expected for clean Arctic marine sediments (Neff, 2002a). Concentrations of Pb in 

Northstar, Liberty, and BSMP sediments sampled between 2000 and 2006 ranged between 3 and 

20 mg/kg (Table 3-21). Concentrations of Zn in the same sediments ranged from 15 to 136 

mg/kg. 
101 

Figure 3-32. Concentrations of barium versus aluminum (a) and chromium versus aluminum (b) 

in sediments collected in 2004, 2005, and 2006. Metals concentrations plotting above 

the upper 99% prediction interval may be from anthropogenic sources. 

From Brown et al. (2009). 

 

Al (%)

0 2 4 6 8 10

Ba (μg/g)

0

300

600

900

1200

2005

2004

2006

Y = 72.9X +115

r = 0.82, n = 192

6H

7G

7A

N06

Linear regression equation, line and 99% 

prediction interval based on 1999-2002 data

(a)

Al (%)

0 2 4 6 8 10

Cr (μg/g)

0

50

100

150

2004

2005

2006

Y = 12.4X + 8.1

r = 0.91, n = 191

Linear regression equation, line and 99% 

prediction interval based on 1999-2002 data

6H L22

(b)

WD 7A

N03
102 

Table 3-21. Mean and range of concentrations of Hg, Pb, and Zn, metals of concern during 

offshore oil and gas development, in sediments from the Northstar, Liberty, and BSMP 

areas, 2000 - 2006. Metals concentrations are mg/kg dry wt (parts per million). Data from 

Brown et al., (2005, 2010). 

Metal Year Northstar Liberty BSMP 

Mercury (Hg) 

2000 0.04 (0 - 0.09) 0.04 (0 - 0.09) 0.03 (0.003 - 0.07) 

2002 0.04 (0.01 - 0.07) 0.03 (0.007 - 0.06) 0.04 (0.006 - 0.08) 

2004 0.04 (0.004 - 0.07) 0.06 (0.023 - 0.097) 0.036 (0.003 - 0.061) 

2005 0.04 (0.016 - 0.113) 0.05 (0.026 - 0.097) 0.03 (0.008 - 0.063) 

2006 0.05 (0.013 - 0.058) 0.03 (0.004 - 0.049) 0.04 (0.013 - 0.066) 

Lead (Pb) 

2000 10.0 (0 - 20.3) 9.39 (0 - 20.3) 8.40 (3.9 - 17.6) 

2002 10.8 (5.1 - 17.1) 8.59 (4.1 - 14.1) 8.32 (5.1 - 18.4 

2004 9.0 (3.8 - 16.2) 11.1 (4.3 - 18.1) 8.6 (4.2 - 14.6) 

2005 10.6 (5.4 - 16.2) 11.8 (5.2 - 20.1) 9.5 (5.6 - 14.5) 

2006 12.0 (4.3 - 16.7) 9.3 (5.5 - 14.2) 10.7 (5.7 - 16.0) 

Zinc (Zn) 

2000 76.2 (0 - 123) 72.0 (0 - 123) 72.6 (38.4 - 122) 

2002 77.4 (27.6 - 107) 62.2 (21.5 - 89.1) 62.1 (24.1 - 100) 

2004 80.5 (21.8 - 115) 83.6 (41.4 - 136) 59.2 (15.1 - 89.2) 

2005 67.9 (38.4 - 101) 82.1 (39.7 - 126) 59.1 (22.1 - 97.1) 

2006 85.1 (37.8 - 113) 65.8 (34.3 - 92.1) 72.6 (46.9 - 105) 

3.2.1.6 14BMetals in Sediment Cores 

Sampling locations for sediment cores were based on the presence of fine-grained sediments and 

revisiting some sites, such as several 1989 sampling sites in Harrison Bay. The average percent 

silt + clay in the 2005-2006 sediment cores was ~70% relative to ~44% for the surface sediments 

The highest average silt + clay content of 88% was found for the core from station 7C (2006) and 

the lowest average silt + clay content was 43% from BP01 (2005). Station 7C is located ~55 km 

from the mouth of the Colville River in western Harrison Bay and station BP01 is located in the 

general area of the Boulder Patch. The finest-grained layer in all of the cores with 95% silt + clay 

was at 18-20 cm in the core from station 7C. The coarsest grained sample, with only 28% silt + 

clay was at 28-30 cm in the core from station N17. 

Concentrations of TOC averaged 1.1% for the 2005-2006 sediment cores, compared to 0.9 % for 

the surface sediment samples. Both these averages show the generally low organic matter content 

for sediments from the study area. The highest average TOC value was 2.1% for the core from 

station 7E in western Harrison Bay and the lowest average TOC was 0.46% for the core from 

station N26 located about 0.2 km northeast of Northstar Island. The most TOC-rich layer was 

from station 7E at 3.88% (2-4 cm) and the lowest TOC value of 0.34% was for station N26 (2-4 

cm). 

Concentrations of trace metals were determined for 47 samples from all seven cores collected in 

2005 and for 34 samples from 5 cores collected in 2006. Each core was sectioned into 0.5- and 
103 

2.0-cm thick layers. The average Al concentration for all sediments from cores was slightly 

higher than found for the 2005-2006 surface sediments. Slightly higher mean concentrations also 

were observed for Ba, Co, Cr, Cu, Fe, Hg, Ni, Pb, Sb, Tl, V and Zn in the cores than the surface 

sediments. These differences are directly related to naturally higher metal concentrations in the 

clay-rich subsurface sediment layers in the cores. 

Some variability was observed in concentrations of metals in most cores, due mainly to shifts in 

the relative amounts of fine-grained sediment. However, the vertical profiles for metal/Al for 

most metals in most cores showed a relatively uniform trend because Al concentrations were 

relatively uniform with increasing depth in each core. 

The historical record of metal levels in sediments from the cANIMIDA study area was 

developed from the 14 cores collected during 2005 and 2006. Collection of sediment cores 

suitable for age-dating was complicated by bottom-fast ice, ice gouging, low net sediment 

accumulation rates, low activities of excess 210Pb and 137Cs, and storm-induced resuspension and 

transport of sediments offshore into deeper water. Even when coring sites were chosen based on 

bathymetry (i.e., semi-restricted basins) or surface sediment composition (i.e., >90% silt plus 

clay), only a few cores were useful for establishing a geochronology over the past 50 to 100 

years using both 137Cs and excess 210Pb. In many instances, extremely low levels or no 

detectable amounts of excess 210Pb (<0.2 dpm/g) or 137Cs (<0.02 dpm/g) were found, even in the 

top 0.5 cm of sediment. Such observations are consistent with previous reports that characterize 

this coastal area as a net erosional environment (Reimnitz and Wolf, 1998). 

Past attempts to reconstruct recent geochronology for coastal sediments from this nearshore 

Beaufort Sea (Weiss and Naidu, 1986; Naidu and others, 2001) have encountered many of the 

same difficulties found during the cANIMIDA study. Based on these difficulties with area 

sediments, a primary goal of the geochronology effort for the cANIMIDA study was to collect 

some representative sediment that was deposited prior to the onset of on-shore development 

during the late 1960s and early 1970s and some sediments that were deposited post-development. 

Concentrations of trace metals were determined for a total of 81 samples from seven cores 

collected in 2005 and five cores collected in 2006. Some variability in concentrations of metals 

was observed in each core, mainly due to variations in amounts of fine-grained sediment. Fortyseven of 1296 metal concentrations (3.6% of the data points) plotted above the upper prediction 

intervals developed for the ANIMIDA study area. Thirty-five of the 47 data points were for 

sediments collected in Harrison Bay (the 7 series of stations) and 3 of the 47 data points were for 

station 2A in Camden Bay. Both Harrison Bay and Camden Bay are not part of the original 

ANIMIDA study area, but were part of the original BSMP. The remaining 9 data points were 

from five different cores in different sediment layers: (1) station PB1A at 3-3.5 cm for Ag, Cd, 

Cu and Ni, (2) station L17B at 3-3.5 cm for As, (3) station N17 at 28-30 cm for As and Hg, (4) 

station N26 at 16-17 cm for Fe, and (5) station BP01 at 9.5-10 cm for Zn. These 9 data points 

plot relatively close to the upper prediction interval and do not reveal any striking anomalies that 

can be clearly tied to anthropogenic sources. The anomalies in the PB1A core from Prudhoe Bay 

may well be linked with a trace sulfide mineral as described previously for the more discernible 

anomalies at stations N14 (2005) and 5D (1999). 

Twenty of the 38 data points from outside the immediate cANIMIDA study area that plotted 

above the upper prediction interval were for Ba, 8 from Camden Bay and 12 from Harrison Bay. 
104 

The expanded scale graph for Ba (Figure 3-33) shows that the highest Ba anomalies in Camden 

Bay were at 19-20 cm for both stations 1C and 2A with generally lower anomalies toward the 

top of each core. Based on the 137Cs data, depths below 17 cm at station 1C and below 9 cm at 

station 2A were deposited prior to 1950. The data for excess 210Pb are scattered in each core; 

however, they support a pre-1950 date for the 19-20 cm sections of the cores. At station 2A, but 

not 1C, the concentration of TOC is >1.5% below 18 cm in the core. In the core from station 1C, 

the TOC is about 0.5% throughout the core. The source of the Ba anomalies is not clear at this 

time; however, diagenetic remobilization, diffusion and reprecipitation of Ba in anoxic layers in 

the sediment column have been observed(McManus et al., 1994; Torres et al., 1995). Dense, 

fine-grained barite from drilling mud also tends to percolate down through coarser sediment 

layers, as was observed near exploratory drilling sites on Georges Bank (Neff et al., 1989). These 

natural processes complicate the identification of drilling mud residues and requires additional 

support for such determinations as described below for Harrison Bay. 

In contrast with the observations in Camden Bay, the Ba anomalies in Harrison Bay 

(Figure 3-33) are found at a depth in the core that can be best explained by the presence of barite 

residues from drilling muds. For example, a vertical profile for the Ba/Al ratio for the sediment 

core from station 7E shows that all 4 samples with significant Ba anomalies are between 2 and 

10 cm in the 30-cm vertical section of sediment (Figure 3-34). The maximum anomaly of 396 

μg/g [anomaly = 859 μg/g – (4.77% Al (72.9) + 115) = 396 μg/g] dates to about 1988 ± 2 years. 

This anomaly is equivalent to a residue of 0.08% barite from drilling mud with 53% Ba (Trefry 

et al., 2007). Drilling activity in the area of Harrison Bay sampled during 2006 is within the area 

of western Harrison Bay where drilling occurred on State lease blocks in 1985 and 1986. The 

closest State/Federal lease blocks were exploratory drilling occurred are Mukluk, drilled to the 

east of station 7E (the red dot in Figure 2-1 south of Mars in central Harrison Bay) in 1983, and 

Mars, drilled to the north in 1986 (Table 1-1 and Figure 2-1). Furthermore, samples collected in 

western Harrison Bay during 1989 had Ba anomalies in the top 2 cm of sediment at stations 7A 

and 7G. The sediment at station 7G was hard and not penetrable for coring in 2006; therefore, 

cores were collected at stations 7A, 7C and 7E. The results for Ba in the core from station 7E 

(Figure 3-34) suggest that the peak concentration from the mid-1980s may have been preserved 

at this site. However, the sediments in the top 6 cm at station 7E contain high levels of TOC at 2-

4%; therefore, a diagenetic explanation for the observed Ba profile cannot be ruled out. More 

detailed study of the sediment column is needed to resolve natural from anthropogenic layers of 

Ba-rich sediment. 

Concentrations of metals in Beaufort Sea sediments have been monitored frequently during the 

last three decades as part of MMS and oil industry monitoring programs. Tables 3-22 and 3-23 

summarize sediment metals data collected between 1984 and 2008 at a large number of locations 

throughout the Beaufort Sea (Neff, 2010). Most samples were collected distant, in time and 

space, from exploratory drilling activities, so the concentrations can be considered to represent 

the natural background. 
105 

Figure 3-33. Concentrations of Aluminum (Al) versus barium (Ba) in sediment core samples 

collected in 2005 (top) and 2006 (bottom), showing the sediment samples that plotted 

above the upper prediction interval. Most of the anomalous Ba concentrations were in 

cores from Camden Bay in 2005 and Harrison Bay in 2006. From Brown et al. (2010). 

 
106 

Figure 3-34. Vertical profile of the Ba/Al concentration ratio in a sediment core collected in 

2006 at station 7E in Harrison Bay. Exploratory drilling occurred on State leases near 

this site in 1985-6 and the Ba/Al peak probably is from drilling muds discharged 

during exploratory drilling. From Brown et al. (2009). 

Grain size distribution and concentrations of organic carbon and trace metals are variable in 

sediments in coastal and offshore waters of the western Beaufort Sea. Trefry et al. (2003) 

reported that nearly all samples of surface sediments and age-dated cores contain natural 

concentrations of several metals, with metal/Al ratios that have been constant for many decades. 

Metal concentrations in river-suspended matter entering the Beaufort Sea in spring runoff 

compare well with metal concentrations in coastal and offshore sediments. Overall, the 

constancy of metal/Al ratios in river-suspended sediment, the surface layers of bottom sediments, 

and deeper, older layers in bottom sediments show that anthropogenic inputs of trace metals have 

not significantly elevated metals concentrations in sediments in areas of offshore oil exploration 

and production in the coastal Beaufort Sea. 

Concentration ranges of metals in water based drilling mud (WBM) used and discharged 

offshore in the Beaufort Sea between 1979 and 1982 are also included in Tables 3-22 and 3-23 

for comparison (Neff, 2010). The only metals in historic Beaufort Sea WBM that sometimes are 

present at higher concentrations than those in Beaufort Sea sediments are barium, chromium, 

lead, and zinc. There are no area-wide trends in metal concentrations that might be associated 

with ocean discharges of WBM and cuttings from more than 50 exploration, delineation, and 

development wells. 

Ba/Al

100 125 150 175 200

Sediment Depth (cm)

0

10

20

30

Station 7E

1988 ± 2 

1950
107 

Table 3-22. Concentrations of arsenic, barium, cadmium, chromium, and copper in sediments 

collected throughout the Alaskan Beaufort Sea between 1984 and 2008 and in water based 

drilling muds (WBM) used in the Beaufort Sea for exploratory wells between 1979 and 

1982. Concentration ranges are mg/kg dry wt (ppm). From Neff (2010). 

Year(s) Arsenic Barium Cadmium Chromium Copper Reference 

Beaufort Sea Sediments 

1984-86 --- 128-704 0.06-0.27 22-89 7.6-30 Crecelius et al. 1991 

1993 10-43 --- 0.06-0.43 77-110 11-63 Valette-Silver et al. 

1999 

1997-99 7-16 116-569 0.11-0.27 13-63 7-27 Naidu et al. 2001 

1999-01 1.0-23 142-863 0.03-0.75 13-104 3.6-46 Trefry et al. 2003 

1999-02a 4.2-28 155-753 0.03-0.82 13-104 3.6-50 Brown et al. 2010 

2001-2 15-31 525-631 0.14-0.20 91-188 31-37 Naidu et al. 2003 

2003 6.9-20 329-649 0.08-0.45 56-84 16-55 Naidu et al. 2006 

2004-06 4.7-25 142-863 0.03-0.77 15-100 3.9-46 Brown et al. 2010 

2008 9.5-22 456-714 0.16-0.31 59-96 15-27 Trefry & Trocine, 

2009 

2008b 10-21 585-

18,300 0.15-0.24 73-135 21-53 Trefry & Trocine, 2009 

Water Based Drilling Muds - Beaufort Sea - 1979 - 1982 

1979-82 --- 520-

36,000 <0.2-1.8 17-1300 1.5-88 NTS 1981, 1982, 1983 a

 Brown et al. (2010) summarizes data for 1999 to 2002 of the MMS ANIMIDA Program; Trefry et al. (2003) 

summarizes data for 1999 to 2001 for the same program. 

b

 Surface sediment samples collected near the Hammerhead exploratory drilling site in Camden Bay in 2008. 

Concentrations of barium, chromium, copper, and lead in some samples collected near the site of 

the Hammerhead exploratory drilling site, drilled in 1985/6 were higher than metals 

concentrations elsewhere in the Camden Bay area. Concentrations of these four metals were 

slightly elevated over a small area at the drill site. There was no evidence of spread of metals 

over a larger area of sediments in the 24 years since drilling. Thus, the concentrations of 

sediment metals summarized in Tables 3-22 and 3-23 can be used as background concentrations 

for comparisons with metals concentrations in sediments collected near historic exploratory drill 

sites shortly after drilling. 
108 

Table 3-23. Concentrations of mercury, nickel, lead, vanadium, and zinc in sediments collected 

throughout the Alaskan Beaufort Sea between 1984 and 2008 and in WBM used in the 

Beaufort Sea for exploratory wells between 1979 and 1982. Concentration ranges are 

mg/kg dry wt (ppm). From Neff (2010). 

Years Mercury Nickel Lead Vanadium Zinc Reference 

Beaufort Sea Sediments - 1984 - 2008 

1984-86 --- --- 5.7-19 37-142 37-123 Crecelius et al. 1991 

1993 0.04-0.15 21-75 11-26 --- 65-160 Valette-Silver et al. 

1999 

1997-99 0.008-0.02 7-34 6-15 24-117 18-96 Naidu et al. 2001 

1999-01a 0.003-0.11 --- 2.8-22 27-173 15-136 Trefry et al. 2003 

1999-02a 0.003-0.20 6.0-48 3.2-22 27-173 15-157 Brown et al. 2010 

2001-02 0.05-0.10b 45-52 16-26 147-211 114-146 Naidu et al. 2003 

2003 0.005-0.09 26-54 11-29 87-136 48-111 Naidu et al. 2006 

2004-06 0.003-0.11 6.9-46 4.3-20 87-156 64-108 Brown et al. 2010 

2008 0.03-0.08 --- 9.9-18 87-156 64-108 Trefry & Trocine 

2009 

2008c 0.04 - 0.06 --- 14 - 49 113 - 131 64 - 108 Trefry & Trocine 

2009 

Beaufort Sea Water Based Drilling Muds - 1979 - 1982 

1979-82 <0.01-0.08 44-88 16-106 160-235 130-380 NTS 1981, 1982, 

1983 a

 Brown et al. (2010) summarizes data for 1999 to 2002 of the MMS ANIMIDA Program; Trefry et al. (2003) 

summarizes data for 1999 to 2001 for the same program. 

b

 Concentration of methylmercury ranged from 0.00001 to 0.00013 ppm. c Surface sediment samples collected near 

the Hammerhead exploratory drilling site in Camden Bay in 2008. 

3.2.1.7 15BHydrocarbons in Surficial Sediments 

Saturated Hydrocarbons (SHC). Concentrations of TSHC in surficial sediments ranged from 

1,100 to 57,000 ng/g dry wt (parts per billion) during the summer 2006 survey, 200 to 38,000 

ng/g during the summer 2005 survey, and 1000 to 33,000 ng/g during the summer 2004 survey. 

Outliers of 100,000 ng/g at Station N14 in 2005 and 85,000 ng/g at Station N08 in 2004 may 

have been influenced by the presence of recent organic material (i.e., peat). The TSHC 

concentrations at Stations N08 and N14 ranged from 600 to 24,000 ng/g in 1999, 2000, and 

2002, respectively. By comparison, TSCH concentrations ranged from 320 to 25,000 ng/g in 

river sediments (Table 3-12) and from 8700 to 260,000 ng/g in peat (Table 3-13). The highest 

TSHC concentration in peat (260,000 ng/g = 2.6%) was in a sample from Arey Lagoon. 

The means and ranges of TSHC concentrations in sediments from the Northstar, Liberty, and 

BSMP areas were highly variable between 2000 and 2006 (Table 3-24). Both the lowest and 

highest concentrations were in sediments collected in the Northstar area in 2005. The ranges of 

TSCH concentrations in sediments were similar in the three areas and in each of the five years. 
109 

There was no significant relationship between TSHC concentrations in sediments and 

concentrations of either %TOC or % silt+clay. 

There was an increase in the mean concentration of TSHC in sediments at Northstar between the 

summer 1999 pre-construction survey and the post-construction surveys in the summers 2000 

through 2006. This increase remained statistically significant when the silt+clay variable was 

used as a covariate in the regression equation. However, when the concentration of TSCH was 

normalized to perylene (a PAH associated with biogenic but not petrogenic hydrocarbon sources) 

in the full statistical model, no significant Northstar*construction interaction effects were noted. 

The composition of SHC in offshore surface sediments was similar to that in the river sediments, 

indicating a possible common TPHC source for the river sediments and the nearshore surficial 

sediments. For example, Colville River, Northstar station 6, and BSMP station 3A sediments 

have a similar SHC profile. Also, the composition of the SHCs in surficial sediments in 2000, 

2002, 2004, 2005, and 2006 are similar to that in the 1999 sediment samples, indicating that no 

new sources of SHC were introduced into these sediments during construction of the Northstar 

facility. 

The most abundant SHC surficial sediments from the development are in the range of C17 to 

C30, similar to the SHC profiles for river sediments (Figure 3-24) and coastal peat (Figure 3-25). 

The SHC assemblage is a mixture of primarily terrestrial biogenic hydrocarbons and lower 

concentrations of petroleum hydrocarbons. This assemblage is clearly dominated by plant wax 

normal (i.e., straight-chain) alkanes in the n-C27 through n-C33 carbon range. This is further 

demonstrated by carbon preference index (CPI) values that range from two to seven for most 

samples, which is characteristic of sediments influenced by terrigenous plant inputs (Wakeham 

and Carpenter, 1976; Boehm, 1984). Two sediment samples have CPI ratios of less than two 

(BSMP 5B [2004] and Northstar N15 [2004]). The lower CPI ratios at stations 5B and N15 are 

due to low SHC concentrations (i.e., trace levels), combined with corresponding low TOC, 

which contribute to CPI ratio uncertainty and potential inaccuracy. 

Traces of lower-molecular-weight alkanes (LALK – n-C9 through n-C20 alkanes), indicative of 

a petroleum source, are visible as additional components relative to the plant wax alkanes in the 

river and offshore sediment. This characteristic petroleum alkane signature in the sediments has 

been well documented by previous studies in the region (Boehm et al., 1987; Steinhauer and 

Boehm, 1992; Boehm et al., 1990; Brown et al., 2004). In 1999, an unresolved complex mixture 

(UCM) characteristic of diesel fuel hydrocarbons was observed in the GC/FID chromatogram for 

the surface sediment sample collected at Liberty station L08. The diesel fuel pattern was 

somewhat weathered, indicating a recent source of diesel fuel contamination at this station. 

Triplicate field replicates collected from L08 in 2000 revealed a similar diesel fuel pattern in one 

of the three field replicates and a visible but less pronounced diesel signature in the other two 

replicates. The diesel fuel pattern was identified in the 2005 L08 sample and was either not 

present or at trace levels in the L08 samples collected in 2002, 2004 and 2006. The absence of a 

similar diesel fuel signature in samples from adjacent stations and the 2002, 2004 and 2006 

samples suggest a very limited or patchy area of sediment contamination. These results warrant 

continued evaluation and monitoring in future field surveys. 
110 

Polycyclic Aromatic Hydrocarbons. Concentrations of TPAH in surficial sediments ranged from 

25 to 1,800 ng/g dry wt during the summer 2006 survey, 31 to 1,600 ng/g during the summer 

2005 survey, and 13 to 1,100 ng/g during the summer 2004 survey. 

The means and ranges of TPAH concentrations in sediments from the Northstar, Liberty, and 

BSMP areas were highly variable between 2000 and 2006 (Table 3-24). Mean TPAH 

concentrations ranged from 460 to 810 ng/g in Northstar sediments, 280 to 710 ng/g in Liberty 

sediments, and 200 to 726 ng/g in BSMP sediments sampled in 2000, 2002, 2004, 2005, and 

2006. TPAH concentrations in individual sediment samples ranged from 13 ng/g to 1800 ng/g, 

with highest concentrations in sediment collected at Northstar station 5A, about 2 km west of the 

production island, in 2000, and at BSMP station 7E, the site of earlier exploratory drilling, in 

2006 (Table 3-24). 

Table 3-24. Mean and Range of concentrations of total PAH, total SHC, total StTr, TOC, and 

Silt+clay in sediments collected in the Northstar, Liberty, and BSMP areas between 2000 

and 2006 in the ANIMIDA and cANIMIDA Programs. Hydrocarbon concentrations are 

ng/g dry wt (parts per billion) and TOC and silt+clay (mud) are % dry wt. Data from 

Brown et al. (2005, 2009). 

Year Total PAH 

(ng/g) Total SHC (ng/g) Total SrTr (ng/g) TOC (%) Silt+Clay (%) 

Northstar 

2000 810 (80 - 1800) 14,000 (1000 - 27,000) 78 (2.9 - 180) 1.3 (<0.1 - 4/4) 61 (2.2 - 91) 

2002 520 (61 - 940) 10,000 (3200 - 22,000) 55 (5.7 - 110) 0.85 (0.3 - 1.8) 63 (3.4 - 92) 

2004 460 (13 - 1100) 15,000 (1000 - 85,000) 53 (7.5 - 110) 0.58 (0.05 - 1.7) 45 (0.4 - 89) 

2005 560 (72 - 950) 17,000 (600 - 100,000) 99 (6.7 - 660) 1.4 (0.1 - 6.4) 34 (10 - 45) 

2006 640 (170 - 1100) 10,000 (1200 - 22,000) 55 (13 - 90) 0.91 (0.23 - 1.4) 63 (10 - 95) 

Liberty 

2000 340 (99 - 610) 8600 (1900 - 12,000) 39 (11 - 62) 0.76 (0.24 - 1.0) 49 (5.3 - 94) 

2002 290 (84 - 420) 6000 (2900 - 10,000) 29 (11 - 52) 0.70 (0.18 - 1.2) 31 (6.4 - 58) 

2004 640 (270 - 960) 17,000 (7300 - 26,000) 52 (21 - 88) 1.0 (0.47 - 2.4) 63 (47 - 91) 

2005 710 (310 - 1100) 15,000(7800 - 23,000) 85 (30 - 140) 0.94 (0.28 - 1.6) 52 (21 - 84) 

2006 280 (25 - 650) 7200 (2000 - 16,000) 25 (3.3 - 60) 0.60 (0.02 - 0.8) 35 (1.2 - 62) 

BSMP 

2000 370 (26 - 630) 7500 (4100 - 8100) 36 (7.8 - 100) 0.71 (<0.1 - 2.0) 44 (1.2 - 85) 

2002 200 (12 - 500) 4400 (440 - 8300) 20 (1.5 - 49) 0.62 (0.14 - 1.26) 37 (0.9 - 84) 

2004 310 (18 - 1100) 8500 (1100 - 25,000) 31 (1.8 - 91) 0.44 (0.08 - 0.91) 43 (0.1 - 100) 

2005 430 (45 - 1400) 8000 (230 - 38,000) 32 (2.1 - 68) 0.67 (0.05 - 1.7) 37 (3.1 - 92) 

2006 726 (92 - 1800) 12,500 (1100 - 27,000) 55 (8.0 - 170) 1.1 (0.08 - 2.8) 46 (4.6 - 94) 

Most of the sediments containing high TPAH concentrations also contained high concentrations 

of perylene, a biogenic hydrocarbon. There was a strong relationship between concentrations of 

TPAH minus perylene and percent silt+clay in sediments collected throughout the development 

area between 1999 and 2006 (Figure 3-35). There were a few outliers with TPAH concentrations 

higher or lower than predicted by the regression. 
111 

There was a small increase in the mean concentration of TPAH in sediments from the Northstar 

area between the 1999 pre-construction measurements and the combined 2000 through 2006 

post-construction measurements. This increase remained statistically significant when the 

silt+clay variable was used as a covariate in the regression equation (Figure 3-35). When the 

concentration of TPAH minus perylene was normalized to perylene in the full statistical model, 

no significant Northstar*construction interaction effects were noted.

Figure 3-35. Regression plot of the concentration of total PAH (μg/kg = ng/g) minus perylene 

versus %silt+clay for all sediment samples collected between 1999 and 2006 in the 

Northstar, Liberty and BSMP areas. The R2

 and 99% prediction intervals are shown. 

Most ratios fall within the 99% prediction intervals. From Brown et al. (2009). 

As noted with the SHC composition profiles, the composition of TPAH assemblage in the river 

sediment and peat samples was similar to that in surficial sediments, indicating a common PAH 

source relationship between the river sediments and the nearshore surficial sediments. Also, the 

composition of the TPAH assemblage in surficial sediments collected from Northstar in 2000, 

2002, 2004, and 2005 was similar to that in the 1999 Northstar sediment samples (Figure 3-36), 

indicating that no new source of PAH was introduced into these sediments. For example, similar 

patterns are noted in the PAH distribution histograms for station N06 in 1999, 2000, 2002, 2004, 

and 2005 (Figure 3-36). 
112 

Figure 3-36. PAH profiles of surface sediments collected at Northstar station N06 in 1999 (top) 

and in 2006 (bottom). Construction of the Northstar production facility occurred in the 

winter of 1999-2000. The PAH profiles are similar, but the concentrations of all 

individual PAH except perylene are lower in 2006 than in 1999. 

From Brown et al. (20010). 

The PAH profiles for most of the offshore surficial sediments indicate that the PAHs are 

primarily of a combined fossil fuel origin (i.e., petroleum, peat, kerogen, and coal) with a 

biogenic component (perylene), and lesser contributions of combustion-source, pyrogenic PAH 

(e.g., 4-, 5-, and 6-ring PAHs). The petrogenic PAHs account for approximately 90 percent of 
113 

the TPAH minus perylene in sediments throughout the study area. Perylene, a biogenic PAH, 

was abundant in surficial sediments and the regional peat samples and often was the most 

abundant single PAH in the overall PAH assemblages (Figures 3-24, 3-25, and 3-36). Although 

perylene is biogenic, it also is present at low concentrations in some crude oils. Northstar crude 

oil contains about 100 ng/g perylene, compared to about 40 ng/g in Colville River Peat. Perylene 

was found in peat at comparable concentrations to those in Beaufort Sea sediments in earlier 

studies in the BSMP area (Boehm et al., 1990 and 1991). 

The PAH profiles usually are similar in sediments throughout all the regions of the development 

area and are characterized by the presence of a full suite of relatively “unweathered” petroleum 

PAHs (i.e., naphthalenes > phenanthrenes) similar to the PAH distribution seen in Northstar 

crude oil and a typical North Slope crude oil. Perylene is found at equal or greater relative 

abundance in the river sediments and peat (Figures 3-24 and 3-25), indicating that the rivers are a 

source of the hydrocarbons in the nearshore sediments, as noted previously for the SHCs. 

The PAH distribution in station L08 sediment from 1999, 2000, 2004 and 2005 shows a clear 

increase in the abundance of 2- and 3-ring petroleum PAHs, particularly the naphthalenes, 

relative to the other sediment samples. This further supports the GC/FID evidence of diesel fuel 

contamination at this station. A slight increase in the abundance of the 2- and 3-ring petroleum 

PAHs also was observed in the 2002 and 2006 samples from L08; however, the increase was not 

as evident as in previous years. Two samples that were identified as potentially being enriched in 

petroleum hydrocarbons based on SHC results in 1999 (sediments from BSMD stations 5D and 

5E) do not show evidence of a corresponding enrichment in PAH or change in PAH distribution 

in subsequent years. In 2000 and 2004, the PAH concentration at 5E (260 and 190 ng/g, 

respectively) was comparable to the levels in 1999, but the concentration in 2002 was 

substantially lower at 46 ug/Kg, due to a corresponding decrease in fine-grained sediment. At 

5D, the PAH concentrations were substantially lower in 2000 and 2002 but present at moderate 

levels in 2004, with no apparent change in overall PAH distribution. These results indicate a 

highly variable sediment substrate at stations 5D and 5E. Additionally, the source of 

hydrocarbon enrichment observed at 5D in 1999 appears to be depleted in PAH versus SHC, 

relative to the regional petroleum hydrocarbon background present in other sediments, 

suggesting an alternate hydrocarbons source in 1999 (e.g., coal or peat). 

Steranes and Triterpanes. Concentrations of TStTr in surficial sediments from the development 

area ranged from 3.3 to 173 ng/g in 2006, 2.1 to 98 ng/g in 2005, and 1.8 to 110 ng/g in 2004. 

One outlier at 660 μg/Kg was detected at Station N14 in 2005. 

The means and ranges of TStTr concentrations in sediments from the Northstar, Liberty, and 

BSMP areas were highly variable between 2000 and 2006 (Table 3-24). Mean TStTr 

concentrations ranged from 20 ng/g in BSMP sediments collected in 2002 to 99 ng/g in Northstar 

sediments collected in 2005. StTr concentrations in individual samples ranged from 1.5 ng/g in 

sediment sample collected at BSMP station 4C in 2002 to 660 in a sediment sample collected at 

Northstar station N14, about 3 km southeast of the Northstar facility, in 2005. Mean and range of 

StTr concentrations tended to be lower in BSMP sediments than in Northstar and Liberty 

sediments in most years. 

In general, the StTr distributions in the sediment samples are indicative of a petroleum pattern, 

with varying abundances of a suite of recent organic material StTr markers. For example, North 
114 

Slope Crude oil contains a characteristic petroleum triterpane pattern dominated by norhopane 

(T15) and C30-hopane (T19). The StTr distributions for most sediment samples include a 

mixture of these characteristic petroleum biomarkers, along with recent organic or biogenic 

markers such as diploptene and other unnamed triterpanes (Peters and Moldowan, 1993). The 

greater abundance of T22 than T21 in some samples provides further evidence of substantial 

recent organic matter inputs to the surficial sediments. In general, the surficial sediment samples 

appear to show a greater abundance of these recent organic materials or biogenic biomarkers, 

suggesting a greater terrestrial influence (e.g., river runoff) to the sediments. Many of the 

sediment samples contain trace levels of oleanane (T18), indicating the presence of a non-North 

Slope Crude, post-Cretaceous/Tertiary petroleum source; i.e., T18 is absent in bulk North Slope 

Crude oil (Bence et al., 1996) and Northstar crude Oil (Figure 3-26). The origin of this 

petroleum signal is unknown, but it probably is from regional background inputs. Seep oils from 

Kavik and Angun may have trace oleananes, as part of their biodegraded biomarker signature. 

The presence of oleanane has also been reported in Canadian McKenzie Delta crude oils to the 

east of the study area (Banet, 1995). 

The StTr distributions in Colville River sediments (Figure 3-24) and peat (Figure 3-25) have the 

same mixture of recent organic matter and petroleum hydrocarbon patterns as observed in many 

of the offshore sediment samples This similarity suggests that there is a strong link between 

Colville River hydrocarbon sources – mostly erosional inputs of regional shales, coal, peat, etc. 

(i.e., natural background) and the sediments. However, given the documented current transport 

regime of East to West in the study area, it is likely that rivers to the East, particularly the 

McKenzie River (Yunker et al. 1991, 1993), as well as the Canning River, influence the 

hydrocarbon abundance and composition in offshore surficial sediments. For example, the StTr 

distribution of Canning River sediment collected to the east of the development area in 2002 is 

dominated by a suite of recent organic markers with a different StTr biomarker pattern that is 

found at greater abundance in some samples in the eastern study area. The importance of 

different Arctic rivers as sources of metals and hydrocarbons in nearshore Beaufort Sea 

sediments depends mainly on the relative concentrations of metals and hydrocarbons in 

suspended sediments and colloidal organic matter from the different rivers. 

The Kuparuk and Sagavanirktok River sediments contain many of the same recent organic 

matter StTr biomarkers, but generally have different distributions than the Colville River 

sediments. In particular, the ratio of T21/T22, where T22 is an order of magnitude higher than 

T21, is characteristic of an immature or recent hydrocarbon source, identified in a 2006 

Sagavanirktok peat sample, possibly indicative of coal. This predominant T22 pattern is also 

found in several of the surficial sediment samples from stations near the Sagavanirktok River 

delta and near the mouth of the Kuparuk River, indicating the influence of these rivers to the 

deposition of surficial sediments at these stations. The presence of the predominant T22 pattern 

at station BSMP station 5D is of particular interest, since the high TSHC and TPAH 

concentrations indicate hydrocarbon contamination at this station. The observed T22 pattern 

indicates that coal particles, possibly from the Kuparuk River, may be one of the sources of the 

hydrocarbon enrichment. 

Several surficial sediment samples have distinctly different StTr distributions. Sediments from 

several stations have StTr distributions more characteristic of a petroleum source, i.e., a 

predominance of hopanes (T15 and T19). In the case of L08, this is not surprising since other 
115 

organic data clearly indicate diesel fuel contamination. However, the abundance of petroleum 

StTr also indicates a petroleum product “heavier” than diesel, as triterpanes are typically 

removed from diesel-range fuels during the distillation process. This result suggests that the 

observed petroleum contamination at L08 is a complex mixture of hydrocarbons including diesel 

and heavier hydrocarbons, such as heavy fuel oil or crude oil. This could be the result of drilling 

mud/cutting residues from historic exploratory drilling nearby (i.e., Tern Island), Exploratory 

wells were drilled from the gravel Tern Island in 1982 and 1987 and an estimated 2380 m3

 of 

water based drilling muds and cuttings were discharged to the water (Table 1-3), as permitted by 

the NPDES permit. The cuttings could have contained small amounts of formation oil or 

kerogens. This hypothesis is supported by the elevated barium concentrations (when normalized 

to Al) observed in the sediment from L08 (1999 only). The petroleum StTr in the surficial 

sediment at 5B are at trace levels (7.8 ug/Kg TSTTr), whereas the StTr distribution at 5E further 

confirms the presence of low levels of a heavy petroleum hydrocarbon source shown by the SHC 

and PAH results, but the specific origins of these “contaminants” are not known. 

3.2.1.8 16BTemporal and Spatial Trends in Hydrocarbons in Surface Sediments 

One technique for examining the spatial trends (variability between stations) in hydrocarbon 

concentrations and compositions in sediments involves examining the relationship between the 

hydrocarbon parameter of interest and percent silt + clay or TOC content. The natural 

background concentrations of nonpolar organic compounds often varies as a function of finegrained sediment (silt + clay) and TOC concentrations. Thus, samples enriched in organics from 

anthropogenic sources can be identified by normalizing the target organic parameter and 

generating a linear regression line and prediction interval on a cross-plot. 

This regression plot technique was used effectively for the 1999 (pre-construction) sediment 

hydrocarbon data to identify sediments enriched in hydrocarbons and data outliers (Boehm et al., 

2001b). For 1999 data, good linear correlation was established between concentrations of TPAH 

minus perylene and TSHC with silt + clay (R2 = 0.83 and 0.69 respectively – station 5D was 

determined to be a statistical outlier and was not included in the regression calculation). The 

value TPAH minus perylene was used to reduce variability introduced to the TPAH data by 

perylene, which can vary widely in abundance based on sediment type. 

These regressions defined the natural geological/geochemical background. In both TPAH and 

TSHC plots, the data point for station 5D was well outside the calculated 99 percent prediction 

interval of the regression line indicating that station 5D sediment was enriched in TPAH relative 

to the expected background for the region. As noted previously, station 5D sediments were 

identified as being contaminated with hydrocarbons, although the source of this contamination is 

still unclear (i.e., coal versus petroleum sources). In the TSHC plot, sediment samples L08 and 

5E were found to fall slightly above the upper 99 percent prediction interval. Based on the 

analytical data, these two samples were also previously identified as being enriched in petroleum 

hydrocarbons. Diesel contamination with possible crude oil was identified in L08 and a heavy 

hydrocarbon product depleted in PAH was identified as a possible source in 5E. 

Overall, these regression techniques provided a sensitive baseline process to measure temporal 

trends of anthropogenic inputs into the system from Northstar, given the radial sampling design 

around the production facility and regional BSMP station coverage. As noted earlier, statistical 

analyses of the 1999 through 2006 data were performed to determine if there were significant 
116 

differences in the measured key diagnostic organic parameters due to the development of 

Northstar. The results of the statistical analyses indicated that the key bulk hydrocarbon 

parameters (i.e., TPAH, TSHC, pyrogenic PAH, etc.) increased significantly in post-1999 

sediments from Northstar. The results of the statistical analyses probably are best summarized in 

a TPAH minus perylene versus silt + clay regression plot for 1999, 2000, 2002, and 2004 - 2006 

Northstar stations (Figure 3-37). In this plot, the regression lines and 95% prediction intervals 

do not overlap, indicating a significant increase in TPAH minus perylene concentrations in 

sediments from Northstar in 2000, 2002, and 2004 - 2006 after adjusting for fines (silt + clay). A 

simple plot of the TPAH normalized to fines clearly shows this trend of increasing PAH 

concentrations at the Northstar stations in 2000 with lower levels in 2002 and 2004 - 2006, but 

still generally higher than 1999. Station N15 in 2002 and 2004 and N11 in 2004 appear to be 

outliers on this plot due to a very low % fines (4.3%, 0.4%, 2.7%, respectively). The 

concentration of TPAH minus perylene at Station N03 in 2004 appears elevated compared to 

previous years, however, the concentration of perylene at this station is also correspondingly 

higher indicating the source of PAH in sediment from this station is from the regional 

background. 

Figure 3-37. Scatterplot of % silt+clay versus TPAH minus perylene in surficial sediments at 

Northstar collected in 1999 through 2006. The 95% confidence interval for the mean 

regression and related statistical calculations for Northstar stations by year are 

included. Station N08 from year 2004 was an outlier and was excluded from this 

graph. From Brown et al. (2010). 
117 

However, a closer examination of the PAH data show that although PAH concentrations in 

Northstar sediments increased post-construction (2000, 2002, and 2004 - 2006 combined), the 

distribution and composition of the PAH assemblage remained relatively unchanged. The 

composition of the sediment hydrocarbons at Northstar is best summarized by a comparison of 

the pyrogenic to petrogenic PAH ratios in 1999, 2000, 2002 and 2004 - 2006. A comparison for 

this ratio for all paired Northstar stations (Figure 3-38) reveals no significant difference between 

years 1999 and 2000 indicating that there were no incremental additions of anthropogenic 

hydrocarbons to the Northstar area as a result of construction activities in 2000. The pyrogenic to 

petrogenic PAH ratios for Northstar stations in 2002 and 2004 show an increasing trend (Figure 

3-38) which then decreases in 2005 and 2006. The statistical comparisons of PAH data 

(Table 3-24) show a significant increase in the pyrogenic to petrogenic PAH ratio region-wide 

for years 2000 through 2004. A subsequent ANOVA revealed that pyrogenic to petrogenic 

ratios for Northstar in 2002 and Liberty/BSMP in 2002 were not significantly different from each 

other, but that the ratios for Northstar in 2004 were significantly greater than Liberty/BSMP in 

2004 and Northstar in 2002. Also, the Northstar 2004 petrogenic PAH concentrations (with 

perylene as a covariate) were significantly less than Northstar 2002 and Liberty/BSMP 2004 

concentrations, while no significant differences were noted for pyrogenic PAHs between regions 

or years. These results suggest that the observed shift to a greater relative proportion of 

pyrogenic hydrocarbons in 2002 and 2004 could be the result of a subtle increase in pyrogenic 

PAH; possibly related to Northstar area inputs (flaring, boat and vehicle traffic, etc.) However, 

this shift in inputs is clearly variable (as shown by the decreased values in 2005 and 2006) and 

not currently of sufficient magnitude to result in a statistically significant increase in 

concentrations of PAH parameters. However, the observed potential of such a shift warrants 

continued sediment hydrocarbon monitoring in the area. 

In 2005 and 2006, sediments from only eight of the 23 previously sampled Northstar stations 

were resampled. The differences in the pyrogenic to petrogenic ratio for this subset of Northstar 

stations were evaluated; the 2005 - 2006 pyrogenic to petrogenic ratio was not significantly 

different from 1999 or 2000 ratios but was significantly lower than the 2002 and 2004 ratios. 

However, it is uncertain if this reduction in the pyrogenic to petrogenic ratio occurred throughout 

the Northstar region due to the limited Northstar sampling in 2005 and 2006. 

Another evaluation of the sources of the PAH was performed using a dibenzothiophene to 

phenanthrene source ratio plot, which has been used in similar investigations of PAH sources in 

the environment (Brown and Boehm, 1993; Page et al., 1998; Boehm et al., 2001a). An 

examination of the source plot for all ANIMIDA and cANIMIDA surficial sediments and source 

samples (Figure 3-39) reveals that the source composition of PAH in the Northstar 2000, 2002, 

and 2004 - 2006 sediments is in the same range as the 1999, 2000, 2002, and 2004 - 2006 BSMP 

and Liberty stations which are representative of the regional hydrocarbon background. Several 

of the Northstar 1999 sediments in the source ratio plot have ratios substantially higher than the 

“regional background” which is likely due to two factors: 1) the very low TPAH concentrations 

found at some of the 1999 Northstar sediments, which introduces variability into the ratio and 

generally results in a ratio increase, and 2) the localized influence of the Kuparuk river which has 

a ratio higher than the “regional background.” 

The Northstar production oil, which was first analyzed in 2002, contains relatively low 

concentrations of organo-sulfur compounds and has a resulting dibenzothiophene to 
118 

Figure 3-38. Pyrogenic:petrogenic ratios of Northstar surficial sediment samples collected in 

1999 through 2006. From Brown et al. (2010). 

phenanthrene source ratio similar to the “regional background” (Figure 3-26). Most other North 

Slope field crude oils have dibenzothiophene to phenanthrene source ratios that are substantially 

higher and are easily distinguished from the background hydrocarbons. This observation limits 

the use of this evaluation technique since the potential contribution of Northstar crude oil could 

not be determined in the case of an accidental release or incremental chronic inputs. However, 

another source ratio plot of the 20S to 20R epimers of steranes and triterpanes (5α,14α,17α-24-

methylcholestane [S25/S28] versus 17α,21β(H)-30-homohopane [T21/T22]) shown in 

Figure 3-40, clearly differentiates all of the North Slope field crude oils and the Northstar 

production oil from the regional background signature in the surface sediments and river source 

samples. This ratio, which is a relative measure of the petroleum hydrocarbon maturity, relies on 

the relative immaturity of the biomarker compounds in the sediments versus the crude oils and 

provides another tool to evaluate potential additions of anthropogenic hydrocarbons to the region 

in the future. 

The earlier observation that the Northstar 1999 sediments may be depleted in hydrocarbons 

relative to the other sediments is further supported by a TPAH minus perylene versus silt + clay 

regression plot for all the 1999, 2000, 2002, and 2004 - 2006 sediment data. In this plot 

(Figure 3-37), the regression and 95% prediction intervals are shown for all data. The plot shows 

a small cluster of Northstar 1999 samples which are be low the 95% prediction interval, 

indicating that these samples have significantly lower TPAH versus silt + clay ratios than the 

overall population of sediment samples. This result corroborates the observed trend of lower 

hydrocarbon levels in Northstar 1999 sediment samples. In addition, as part of the statistical 

analyses, a regression model comparing Northstar 1999 samples to 1999 BSMP and Liberty 

samples for all key parameters revealed that Northstar 1999 sediments were significantly lower 
119 

 

Figure 3-39. Double Ratio Source Plot of C2D/C2P vs. C3D/C3P for surface sediments from 

BSMP, Liberty, Northstar, and Arctic rivers collected between 1999 and 2006 and 

North Slope and for Northstar crude oils. From Brown et al. (2010). 

in all bulk hydrocarbon parameters (e.g., Total PAH, TPHC, Petrogenic PAH, etc.) than 1999 

BSMP and Liberty sediments. A further regression comparison of the Northstar 2000, 2002 and 

2004 samples versus the BSMP and Liberty 2000, 2002, and 2004 samples resulted in no 

significant difference for all bulk hydrocarbon parameters and most of the diagnostic ratios. The 

results of this analysis are further illustrated by a PAH regression plot that shows overlap 

between the regression lines and 95% prediction intervals (i.e., no significant difference) for the 

Northstar, BSMP, and Liberty sediments for 2004 - 2006. 

As noted previously, the initial statistical comparisons revealed that Northstar 1999 sediments 

were significantly lower in all bulk hydrocarbon parameters (e.g., Total PAH, TPHC, Petrogenic 

PAH, etc.) than 1999 BSMP and Liberty sediments which resulted in a positive Northstar and 

Northstar/construction effect (i.e., a significant increase in these parameters associated with 

Northstar construction). However, a subsequent, improved statistical model with perylene as a 
120 

Figure 3-40. Double Ratio Source Plot of S25/S28 vs. T21/T22 steranes and triterpanes in 

BSMP, Liberty, Northstar, and River Sediment Samples collected in 1999 through 

2006. From Brown et al. (2010). 

covariate resulted in no significant increases in any of the key diagnostic hydrocarbon 

parameters due to Northstar or Northstar/construction effects. The use of perylene as a covariate 

parameter to normalize sediment data is particularly effective due to the absence or only trace 

levels of perylene in the anthropogenic sources of hydrocarbons to the region (petroleum and 

pyrogenic hydrocarbons), and the relative enrichment of perylene in the regional background 

(river and sediment sources). . 

As was noted in the statistical analyses using perylene as a covariate, this plot shows no 

significant increase in PAH due to Northstar or Northstar/construction effects, and six stations 

fall outside the prediction intervals. Sediments from stations N11 and N14 appear to be slightly 

enriched in perylene, possibly due to the proximity to the Kuparuk River, which contains 

sediments rich in perylene. Station 1A sediments also appear to be enriched in perylene. Station 

4A and 2G sediments appear to be somewhat depleted in perylene relative to TPAH, but had no 

signs of petroleum contamination. Petroleum hydrocarbon contamination was previously 

identified in Station L08 using other interpretative techniques. The relationship of perylene to 

other hydrocarbons in surface sediments clearly warrants further investigation, however, these 

results indicate that normalization of PAH and other hydrocarbon parameters to perylene is 

another valuable tool capable of identifying anthropogenic hydrocarbons inputs into the surface 

sediments of this dynamic coastal region. 
121 

Based on the results of the data evaluations, we considered three hypotheses for the observed 

absolute increase in sediment hydrocarbon concentrations in the Northstar area after 1999 with 

no corresponding change in source or composition: 1) the increase could be related to deposition 

of very fine-grained material associated with the gravel used to construct Northstar Island and 

disturbances from the pipeline construction; 2) the ice roads made during the Northstar 

construction may have diverted suspended sediments from the Kuparuk river flow during breakup, and increased the deposition of fine-grained hydrocarbon-bearing sediments in the Northstar 

area; and 3) that the Northstar sediments in 1999 were depleted in fine-grained sediment and 

hydrocarbons during the 1999 sampling period. 

The first two hypotheses would require that the source of fine-grained material deposited in the 

Northstar area after 1999 (e.g., Northstar construction gravel and/or Kuparuk river sediment) was 

enriched in PAH and other hydrocarbons relative to the fine-grained material in the existing 

surface sediment. This is not the case. Analyses of the Kuparuk river sediments reveal that the 

river sediment is not enriched in hydrocarbons relative to the Northstar area sediments, and is 

thus unlikely to account for the observed increase. It is possible that the very fine-grained 

fraction of Northstar construction gravel could be enriched in hydrocarbons due to burial and 

compaction of the historic Kuparuk river sediments, which were the source of the gravel (the 

construction gravel was mined from the Kuparuk river delta). However, subsequent analysis of 

“source material” from the Kuparuk river gravel mine (borrow pit) revealed results similar to the 

previously analyzed Kuparuk River sediments. 

The most likely explanation is the third hypothesis that the Northstar surface sediments were 

depleted in hydrocarbons in 1999. The organic analyses and resulting statistical comparisons of 

the 1999, 2000, 2002, and 2004 Northstar, BSMP and Liberty data, support this explanation. In 

addition, during the 1999 sampling survey, nearly all the Northstar stations were sampled within 

24 hours after a six-day gale (peak winds in excess of 25 knots). This storm resuspended 

substantial amounts of surface sediments into the water column (Boehm et al., 2001b) and would 

account for the observed depletion of hydrocarbons in the 1999 Northstar sediments and 

corresponding lower abundance of fine-grained sediment. Regardless of the mechanism for the 

observed increase in hydrocarbon concentrations at Northstar, it is critical to recognize that the 

hydrocarbon assemblage identified at Northstar in 1999, 2000, 2002, and 2004 - 2006 represents 

the natural background (both in composition and concentrations) and is not indicative of 

anthropogenic inputs in spilled oil or drilling muds/cuttings. Although oil based and synthetic 

based drilling muds were used to drill deeper sections of some of the production and disposal 

wells at the Northstar facility, no mud or cuttings were discharged to the ocean. However, 

equally important is the recognition that the monitoring techniques and data evaluation 

approaches used in this study are very sensitive and capable of identifying incremental 

anthropogenic inputs to the system, if they occur. 

Summary. The hydrocarbon measures do not reveal any detectable contaminant input, except 

possibly from gas flaring at Northstar, which can be attributed to the Northstar operations, when 

viewed against the pre-construction levels in the sediments and the pre-construction hydrocarbon 

composition and regional distribution. 
122 

3.2.1.9 17BGeochronology of Hydrocarbons in Sediment Cores 

SHC, PAH, and StTr were analyzed in the ten core samples collected in 2005 and 2006. The 

hydrocarbon dataset for the core sediments from 2005 and 2006 data from ten core samples 

collected. Nine of the cores also have reliable deposition rates and detailed geochronology. 

Hydrocarbons were analyzed at several depth intervals in the cores in an effort to better 

understand the temporal pattern of hydrocarbon deposition in sediments of the Beaufort Sea 

deposition area. The available geochronology data indicate that most of the sediments in the area 

represent pre-development (i.e., pre-1970) sediment deposition and probably are much older. 

Saturated Hydrocarbons. Most of the SHC profiles in sediments from different depths in the 

cores are consistent with a mixture of primarily terrestrial biogenic hydrocarbons and lower 

contributions of petroleum hydrocarbons. This assemblage is clearly dominated by plant wax 

normal alkanes in the n-C27 through n-C33 carbon range. This is further demonstrated by 

carbon preference index (CPI) values for all sediment core samples that range from 4.6 to 6.9, 

which is characteristic of sediments influenced by terrigenous plant inputs (Wakeham and 

Carpenter, 1976; Boehm, 1984). The SHC profiles in the sediment core samples closely 

resemble those in surface sediments from the same locations. 

Traces of lower molecular weight alkanes (LALK; n-C9 through n-C20 alkanes), possibly 

indicative of petroleum sources, are visible as minor components relative to the plant wax 

alkanes in the core sediments and in the river sediment samples. This natural “background” 

petroleum alkane signature in the sediments has been well documented by previous studies in the 

region, including earlier ANIMIDA work (Boehm et al., 1987; Steinhauer and Boehm, 1992; 

Boehm et al., 1990; Boehm et al., 2001b; Brown et al., 2002). These cores confirm the presence 

of “petroleum” alkanes prior to North Slope development. 

TSHC concentrations often are correlated with %silt+clay at different depths in sediment cores. 

This is consistent with the hypothesis that much of the SHC originates from terrestrial plant 

material delivered to offshore sediments in spring river runoff. 

 

Polycyclic Aromatic Hydrocarbons. The PAH distributions in sediments at different depths in 

the cores show that the PAH are primarily petrogenic (i.e., petroleum, peat, and coal) with 

smaller contributions of pyrogenic PAH (e.g., 4-, 5-, and 6-ring PAHs), with a variable biogenic 

component (perylene). The petrogenic PAH account for approximately 90 percent of the TPAH 

minus perylene throughout the core samples, including the surface sediment layer, as discussed 

above. Perylene was abundant in the core sediments and often was the most abundant single 

PAH (Figure 3-41). Several cores showed a clear trend in increasing perylene concentrations 

with depth (Figure 3-42), likely a product of diagenesis in the deeper sediment strata. Perylene 

concentration often increases with depth in the sediment, because diagenesis of perylene 

precursors to perylene occurs primarily in deeper, suboxic and anoxic sediment layers 

(Wakeham and Farrington, 1980). 

The main effect of discharge of drilling muds and cuttings on nearby sediments is organic 

enrichment of surface layers. This is caused by microbial degradation of organic matter in the 

discharged solids, leading to oxygen depletion in the sediments (Neff, 2010). Sediment cores 

through a layer of drilling wastes on the sea floor often show elevated concentrations of PAH, 
123 

Figure 3-41. PAH profiles for the 0-2 cm (top) and 8-10 cm intervals in a sediment core 

collected at Northstar station N26 in 2005. From Brown et al. (2010). 

including perylene, and SHC in near surface sediment layers. These hydrocarbons probably are 

from the organic-rich shallow (top few hundred meters) sediment layers cored and then 

deposited directly on the sea floor during drilling of the top hole (Neff, 2010). This is the pattern 

in a sediment core from BSMP station 7E, where there is other evidence of former drilling 

activities (Figure 3-43). Highest concentrations of TPAH and perylene were at about 3 cm below 

the surface and concentrations of TSHC reached a maximum at about 5 cm, where % silt+clay is 

lowest. 

The PAH distributions usually are similar in all the cores at surface and at depth, and are 

characterized by the presence of a full suite of petroleum PAH similar to the PAH distribution 

seen in the Northstar crude oil. Perylene is found at equal or greater relative abundance in the 

river sediments and peat (Figures 3-12 and 3-13) compared to abundance in surface and 
124 

Figure 3-42. Profiles of TPAH, perylene, TSHC (TPHC), TStTr (Total ST) concentrations, 

pyrogenic/petrogenic PAH ratios, and % silt+clay in a sediment core from BSMP 

station 7A. From Brown et al. (2010). 

subsurface layers of offshore sediment, which supports the relationship of the rivers and peat 

erosion as sources of most of the hydrocarbons in the nearshore sediments. Low levels of 4-, 5-, 

and 6-ring combustion PAHs also are also present, but are generally only a minor component of 

the overall PAH composition in the sediments. 

Steranes/Triterpanes . In general, the StTr distributions in the sediment core samples are 

indicative of a petroleum source (Figures 3-42 and 3-43), with varying abundances of a suite of 

recent organic material triterpane markers. For example, Northstar crude oil has a characteristic 

petroleum StTr pattern dominated by 13β,17α-diacholestane-20S (S4), 17α(H),21β(H)-hopane 

(T19), C23-diterpane (T4), and 22S-17α(H norhopane (T21) (Figure 3-26). The triterpane 

distributions for the core sediment samples are composed of a mixture of some of these 

characteristic petroleum triterpanes, as well as recent organic or biogenic markers such as 

diploptene and other unnamed triterpanes. 
125 

Figure 3-43. Vertical profiles of TPAH, perylene, TSHC (TPHC), TStTr (Total ST) 

concentrations, pyrogenic/petrogenic PAH ratios, and % silt+clay in a sediment core 

from BSMP station 7E, where there is evidence of exploratory drilling activities in the 

1980s. From Brown et al. (2010). 

The StTr distributions in river sediments and peat contain recent organic matter and petroleum 

hydrocarbon StTr patterns (Figure 3-24 and 3-25) with some similarities to those observed in the 

offshore sediment samples. This similarity suggests that there is a strong link between the river 

hydrocarbon sources – mostly erosional inputs of regional rock (shale) coal, peat, etc. (i.e., 

natural background) and the offshore sediments over time. 

Comparisons of Hydrocarbons over Time. The key diagnostic organic parameters calculated for 

sediment core sections are important in examining the historical trends of hydrocarbons in the 

sediment record. As discussed earlier, reliable geochronology could be established for nine 

sediment cores Comparisons of selected key diagnostic parameters in the form of core profiles in 

conjunction with simple statistical treatments, allow an assessment of pre- and post-development 

hydrocarbon trends over time. 
126 

In general, comparisons of the core profiles for key diagnostic organic parameters for all of the 

cores do not show any clear trends that would indicate an increase in petroleum hydrocarbon 

inputs over time. The core profile from station 7C where geochronology could not be 

established (likely representing a historical pre-development record) is generally uniform and 

shows little variability of the hydrocarbon parameters over time. The cores for which pre- and 

post-development dates can be established generally show uniform distributions of key 

parameters throughout the cores, with some variability in specific core sections, such as that for 

station 7E (Figure 3-43). However the overall composition of the three classes of hydrocarbons 

analyzed are all similar throughout the cores and are consistent with the regional background 

hydrocarbon sources identified in the surface sediments (Figure 3-41). 

In examining hydrocarbon trends in all of the cores, one useful technique involves examining the 

relationship between the organic parameter of interest and TOC content or alternatively, the 

%silt plus clay or perylene concentration. The natural background concentrations of TOC in the 

study area tend to co-vary with perylene concentration. Thus, samples enriched in organics from 

anthropogenic sources can be identified by normalizing the target organic parameter and 

generating a linear regression line and prediction interval on a cross-plot. A regression of TPAH 

minus perylene versus perylene concentration for all sediment core data for 2005 and 2006 

demonstrates that most TPAH minus perylene/perylene ratios in different sediment layers in the 

cores fall within the 95% prediction intervals, indicating that the 2005 and 2006 core sediment 

samples usually do not have a TPAH concentrations different from the historical natural 

background for the region. 

Another evaluation of the sources of PAH in the core samples was performed using a 

dibenzothiophene-to-phenanthrene source ratio plot, which was used earlier is this study to 

investigate PAH sources in surface sediments. Figure 3-44 is a source plot for all the 2001, 2005 

and 2006 core sediments and additional source samples (i.e., field oils, river sediments and peat). 

The plot reveals that the source compositions of PAH in the core samples are generally similar 

(i.e., the data points cluster together on the plot) with some variability that can be attributed to 

local riverine source influences. For example, data points from core 2A (just east of the Canning 

River delta) tend to cluster below and to the left of the main grouping of data points and near the 

Canning River sediment data. The sediment core ratios cluster separately from the ratios for 

North Slope crude oil samples, but near the ratio for Northstar crude oil. However, Northstar 

crude oil has low concentrations of dibenzothiophenes, so it is unlikely that the PAH in sediment 

cores, which usually include abundant dibenzothiophenes (Figure 3-41), are derived from 

Northstar crude oil. 

Another source ratio plot of the 20S to 20R epimers of steranes and triterpanes (5α,14α,17α-24-

methylcholestane [S25/S28] versus 17α,21β(H)-30-homohopane [T21/T22]) of all the 2001, 

2005 and 2006 core samples and sources samples (Figure 3-45) shows that the core data fall well 

within the range defined by the cluster of all of the surface sediment samples from the area. This 

provides further evidence that the sediment core data are representative of the regional 

hydrocarbon background, and do not indicate any substantial influence from post-development 

anthropogenic hydrocarbon inputs from the Northstar or Prudhoe Bay area, as indicated by the 

distance on the plot between the data points for Northstar and North Slope crude oils and the 

sediment cores. 
127 

Figure 3-44. Double Ratio Source Plot of C2D/C2P vs. C3D/C3P for sediment core samples 

collected in 2001, 2005, and 2006, Northstar crude oil, river sediments, and peat. 

From Brown et al. (2010). 

Figure 3-45. Double ratio source plot of S25/S28 versus T21/T22 petroleum biomarkers for 

BSMP, Liberty, Northstar sediment core samples. From Brown et al. (2010). 
128 

Overall, the organic analyses of the sediment cores collected during 2005 and 2006 have 

provided an important historical perspective on hydrocarbons in the sediments from the study 

area. The results have shown that the concentrations and sources of hydrocarbons are generally 

uniformly consistent over the past 50 or more years and represent a regional background 

assemblage. For most hydrocarbon parameters, there are no significant increases (after 

geochemical normalization) of hydrocarbon concentrations in the sedimentary record after the 

onset of oil and gas development in the Prudhoe Bay area. 

3.3 14BCharacterization of Metals and Hydrocarbons in Tissues of Marine Animals 

in the ANIMIDA/cANIMIDA Study Area 

Large numbers of indigenous marine invertebrates (bivalve mollusks, amphipods, isopods, and 

mysids) and marine/anadromous fish were collected at a large number of stations in the 

Northstar, Liberty, and BSMP in 2004, 2005, and 2006 for analysis of tissue metals and 

hydrocarbons (Tables 2-1 and 2-2, Figure 2-3) (Neff et al., 2009). Mussels and sempermeable 

membrane devices (SPMDs) were deployed in cages at several stations in the same areas in an 

attempt to measure concentrations of bioavailable PAH in the water column. Marine animals had 

been sampled and mussels deployed at many of these stations one or more times in 1999 through 

2002 for analysis of tissue metals and hydrocarbons as part of the Phase 1 and 2 ANIMIDA 

Project (Boehm et al., 2001; Spies et al., 2003; Brown et al., 2004). The objective of this 

sampling was to characterize bioavailability of several metals and three hydrocarbon classes 

(SHC, PAH, and StTr) to marine animals living in the oil and gas development area of the 

Alaskan Beaufort Sea and to determine if there were regional differences or temporal changes in 

tissue residues of metals and hydrocarbons that could be linked to exploration and development 

activities. 

3.3.1 59BMetals in Tissues of Marine Animals 

3.3.1.1 18BFish 

Concentrations of 13 metals were measured in the whole tissues of eight species of marine or 

anadromous fish indigenous to the nearshore Beaufort Sea between 2000 and 2006 (Table 3-25). 

Concentrations of metals for which comparison data were available (Table 3-26) were in the 

normal range in fish from the Beaufort Sea. The metals of greatest toxicological concern (As, 

Cd, Cr, Cu, Hg, Pb, and Zn) were present in fish tissues at concentrations well below potentially 

toxic values. 

Concentrations of most metals were similar in different species of fish (Table 3-27). Arctic cod, 

four horn sculpin, and Arctic flounder are marine fish and Arctic char, Arctic cisco, least cisco, 

broad whitefish, and humpback broad whitefish are anadromous. There were no consistent trends 

in concentrations of metals in fish tissues. Demersal species, such as four horn sculpin tended to 

contain higher concentrations of metals than the more pelagic species. An anadromous species, 

arctic char, tended to contain lower concentrations of several metals (As, Ba, Cr, Fe, Ni, and V) 

than the other species did, perhaps from ingestion of fine grained suspended sediments from 

river water (Trefry et al., 2009). 
129 

Table 3-25. Concentration ranges of several metals in fish, mussels, amphipods, and clams 

collected in the Beaufort Sea between 2000 and 2006 as part of the ANIMIDA and 

cANIMIDA Programs, compared to the National Status and Trends median concentration 

ranges for mussels or oysters collected in US coastal waters between 1986 and 2003 

(From O’Connor and Lauenstein, 2006). Concentrations are g/g dry wt (ppm). Tissue 

metals data from Brown et al. (2005) and Neff et al. (2009). 

Metal Fish Mussel Amphipod Clam NS&T Medians 

Silver (Ag) 0.01 – 0.35 0.05 – 2.5 0.8 – 4.0 0.04 – 0.13 --- 

Aluminum (Al) --- 131 - 2000 96 - 1200 98 - 2200 --- 

Arsenic (As) 0.55  16 6.2 - 13 4.0  17 8 - 16 8.1 – 9.6 

Barium (Ba) 0.30 – 47 2.9 - 20 7.4 - 59 7 - 40 --- 

Beryllium (Be) --- 0.01 – 0.06 0.01 – 0.03 0.03 – 0.08 --- 

Cadmium (Cd) 0.01  0.37 0.29 – 5.4 0.3  2.4 0.53  13 2.1 – 2.9 

Cobalt (Co) --- 0.46 – 2.6 0.6 – 2.9 0.8 – 4.0 --- 

Chromium (Cr) 0.04 – 3.8 0.65 – 7.3 --- --- --- 

Copper (Cu) 1.1  21 5.4 9.40 41 - 210 7.0 - 24 (8.0 – 10)a

(91 – 140)b

Iron (Fe) 19 - 1200 200 - 2000 100 - 950 770 - 3600 --- 

Mercury (Hg) 0.02  0.5 0.01  0.45 0.02  0.19 0.0  0.13 0.09 – 0.11 

Manganese (Mn) --- 5.8 - 260 10 - 71 47 - 640 --- 

Nickel (Ni) 0.03  4.4 1.1 – 4.9 0.8  6.7 1.92  5.34 1.6 – 2.2 

Lead (Pb) 0.01 – 2.6 0.22  1.1 0.05  0.7 0.18  1.9 0.63 – 0.98 

Antimony (Sb) --- 0.01 – 0.03 0.01 – 0.04 0.01 – 0.06 --- 

Selenium (Se) 0.94  5.7 --- --- --- 2.3 – 3.0 

Tellurium (Tl) --- 0.01 – 0.04 0.01 – 0.03 0.01 – 0.03 --- 

Vanadium (V) 0.05 – 5.1 0.91 – 6.7 0.5 – 3.4 1.3 – 6.9 --- 

Zinc (Zn) 36.0  120 47  130 54 - 170 62 - 130 (110 – 140)a

(1600 – 2400)b 

a

 Mussels 

b

 Oysters
130 

Table 3-26. Concentrations of several metals and total polycyclic aromatic hydrocarbons 

(TPAH) in whole or muscle tissues of marine bivalve mollusks, crustaceans, and fish from 

unpolluted marine environments throughout the world. Concentrations are g/g dry wt. 

From Neff (2002). 

Chemical 

Bivalve Mollusks Crustaceans Fish 

Geomean Range Geomean Range Geomean Range 

Arsenic 11 0.13 – 214 15 <0.1 – 270 6.1 0.05 – 450 

Barium 4.4 0.09 – 179 3.4 0.02 – 202 0.13 0.007 – 49 

Cadmium 1.18 0.05 – 26.1 1.85 0.14 – 117 0.10 0.001 – 5.8 

Mercury 0.17 0.004 – 11.7 0.45 0.02 – 6.2 0.77 0.01 – 115 

Chromium 3.5a 0.1 – 10.0 2.6a 0.12 – 10.1 2.1a 0.03 – 5.8 

Copper 51.8a 6.4 – 150 75.4a 8.8 – 241 3.9a 0.6 – 26 

Lead 4.5a <0.1 – 21.4 4.5a 0.03 – 17.5 7.09a 0.02 – 55.9 

Zinc 290a 40 – 1315 68.6a 23.9 – 96.5 28.8a 4.1 – 58.8 

TPAH 0.65 0.003 – 1729 0.17 0.004 – 13.4 0.19 0.002 – 23.4 

a

 arithmetic mean.

Table 3-27. Concentrations of 13 metals in whole samples of seven species of fish collected 

from the Beaufort Sea study area during the summer of 2004. n = number of replicates. 

Concentrations are g/g dry wt. Metals concentrations that were significantly different in 

a fish species at different sampling locations are highlighted. 

Metal Parameter 

Arctic 

Char 

(n= 2-3) 

Arctic 

Cisco 

(n= 4-5) 

Arctic 

Cod 

(n= 4-5) 

Arctic 

Flounder 

(n= 2) 

Broad 

Whitefish 

(n=2) 

Four 

Horn 

Sculpin 

(n=5-6) 

Least 

Cisco 

(n= 6) 

Ag 

Mean±SD 0.04±0.01 0.02±0.01 0.10±0.03 0.03±0.01 0.07±0.06 0.19±0.10 0.02±0.01 

Range 0.03-0.05 0.01-0.03 0.06-0.14 0.02-0.03 0.02-0.11 0.06-0.35 0.01-0.04 

As 

Mean±SD 2.51±0.80 3.05±0.52 9.45±5.33 5.74±0.88 1.43±0.44 4.87±2.32 2.98±0.91a

Range 1.59-3.03 2.57-3.79 2.07-16.2 5.12-6.36 1.12-1.74 3.40-9.47 1.56-3.94 

Ba 

Mean±SD 1.9±0.3 2.5±4.3b

 4.0±2.3 5.6±2.1 2.7±0 9.3±4.1 1.3±1.0 

Range 1.7-2.1 0.3-8.9 1.7-6.9 4.1-7.0 2.7-2.7 3.0-14.2 0.5-3.0 

Cd 

Mean±SD 0.10±0.04 0.07±0.04 0.17±0.11 0.04±0.02 0.05±0.03 0.18±0.09 0.06±0.06 

Range 0.05-0.13 0.03-0.14 0.05-0.27 0.03-0.06 0.03-0.07 0.05-0.32 0.02-0.18 

Cr Mean±SD 0.12±0.04 0.19±0.20 0.53±0.40 0.57±0.12 0.32±0.07 0.34±0.54 0.11±0.03 

Range 0.09-0.17 0.05-0.54 1.14±0.12 0.48-0.65 0.27-0.37 0.22-1.17 0.16±0.07 

Cu Mean±SD 4.5±0.3 3.0±0.5 4.5±2.2 3.4±0.9 3.7±0.7 11.1±4.1 2.3±0.5 

Range 4.2-4.7 2.4-3.6 2.2-7.9 2.7-4.0 3.2-4.2 6.1-18.2 1.5-2.9 

 
131 

Table 3–27. Continued. 

Metal Parameter 

Arctic 

Char 

(n= 2-3) 

Arctic 

Cisco 

(n= 4-5) 

Arctic 

Cod 

(n= 4-5) 

Arctic 

Flounder 

(n= 2) 

Broad 

Whitefish 

(n=2) 

Four 

Horn 

Sculpin 

(n=5-6) 

Least 

Cisco 

(n= 6) 

Fe 

Mean±SD 54.5±17.3 63.0±30.1 172±165 90.4±68.7 162±26.2 252±161 56.7±15.5 

Range 37.7-72.2 40.0-112 37.2-424 41.8-139 143-180 114-541 44.5-87.1 

Hg 

Mean±SD 0.06±0.02 0.06±0.02b 0.03±0.02 0.17±0.09 0.07±0.04 0.21±0.13 0.14±0.06 

Range 0.05-0.09 0.04-0.08 0.02-0.06 0.11-0.23 0.05-0.10 0.10-0.45 0.05-0.20 

Ni 

Mean±SD 0.06±0.02 0.19±0.10 0.60±0.24 0.36±0.16 0.20±0.03 0.48±0.33 0.19±0.10a

Range 0.05-0.08 0.11±0.37 0.30-0.91 0.24-0.47 0.18-0.22 0.17-0.92 0.09-0.35 

Pb 

Mean±SD 0.19±0.13 0.07±0.04 0.30±0.19 0.11±0.06 0.11±0.10 0.22±0.09 0.10±0.05 

Range 0.11-0.33 0.02-0.12 0.09-0.57 0.07-0.15 0.03-0.18 0.07-0.32 0.04-0.18 

Se 

Mean±SD 3.69±1.23 1.94±0.46b 3.34±0.99 3.19±0.27 2.64±0.45 4.10±1.03 2.30±0.23 

Range 2.71-5.07 1.57-2.53 1.73-4.12 3.0-3.38 2.32-2.96 2.49-5.66 1.89-2.59 

V 

Mean±SD 0.14±0.05 0.15±0.15 1.12±1.18 0.55±0.14 0.57±0.09 1.32±1.08 0.13±0.06 

Range 0.10-0.19 0.05-0.40 0.19-3.02 0.45-0.65 0.50-0.63 0.34-3.38 0.05-0.19 

Zn 

Mean±SD 72.0±22.3 58.8±21.2b 82.9±22.1 91.6±16.1 50.5±12.3 94.0±13.1 66.5±26.1 

Range 53.1-96.6 36.0-82.5 44.5-97.8 103-80.2 41.8-59.2 70.8-106 38.7-109 

a

 Northstar > Liberty; b Liberty > Northstar. 

Concentrations of all metals were similar in all species collected at Liberty and Northstar in 

2004, 2005, and 2006. Figure 3-46 summarizes the concentrations of 13 metals in tissues of 

several fish collected at Northstar and Liberty in 2006. When fish tissue data for 2005 and 2006 

were combined, concentrations of Ag and Cu were significantly higher in fish from Northstar 

than in those from Liberty. The concentration of Se was significantly higher in fish collected in 

2006 than in those collected in 2005. However, when combined fish tissue data for 2004, 2005, 

and 2006 were compared, there were no significant differences by year or location. 

3.3.1.2 19BMarine Crustaceans 

Amphipods (usually Anonyx nugax) were collected from several stations throughout the 

development area in all years of the ANIMIDA and cANIMIDA Projects for analysis of tissue 

metals and hydrocarbons (Table 2-1). Metals also were measured in isopods (Saduria sabini) 

collected at four BSMP stations and three Liberty stations in 2005. The amphipods contained 

higher concentrations of most metals than the fish did (Table 3-25). The amphipods and isopods 

contained similar concentrations of most metals. 

Differences were relatively small for concentrations of metals in amphipods from the Northstar, 

Liberty, and BSMP areas in 2004, 2005, and 2006. Table 3-28 summarizes the mean 

concentrations of 18 metals in amphipods collected in 2004. There were significant differences 

among locations or year in concentrations of 9 metals in amphipod tissues (Table 3-29). Most 

significant differences were by year. None of the differences were large or ecologically 

significant. 
132 

Figure 3-46. Mean ± SD concentrations of 13 metals in whole soft tissues of mixed assemblages 

of fish collected in the Liberty and Northstar areas in 2006. Concentrations are μg/g 

dry wt. From Neff et al. (2009). 

Annual mean concentrations for each of 18 metals in amphipods from the coastal Beaufort Sea 

were plotted with their respective standard deviations (square root of the variance). Plots for the 

metals most likely to enter the marine environment as a result of offshore oil and gas operations 

or that pose the greatest ecological hazard are included in Figures 3-47 and 3-48. Table 3-30 

shows the grand means and standard deviations for the 1999-2006 data along with the relative 

standard deviations [RSD = (mean/SD) x 100%], maximums and minimums. The 1999-2006 

data sets were used to create Table 3-30 so that the same time interval would be used for all 

metals. Identification of any future changes in metal concentrations in amphipods relies on (1) a 

relatively low RSD or (2) low enough absolute metal values that changes can be distinguished 

before an adverse impact occurs. 

0

1

2

3

4

5

6

7

8

Ag As Ba Cd Cr Cu Hg Ni Pb Se V

Concentration (ug/g dry).

Liberty

Northstar

11 Metals in Multi-Species

Samples of Fish - 2006

0

50

100

150

200

Fe Zn

Concentration (ug/g dry).

Liberty

Northstar 2 Metals in Multi-Species

Samples of Fish - 2006
133 

Table 3-28. Concentrations of 18 metals in amphipods (Anonyx nugax) collected from three 

locations in the Beaufort Sea in 2004. n= number of samples. Concentrations are g/g dry 

wt (ppm). 

Metal Parameter Northstar 

(n= 3) 

Liberty 

(n= 2) 

BSMP 

(n= 3) 

Ag Mean±SD 4.05±1.69 2.98±0.07 2.41±0.51 

Range 2.75 - 5.96 2.91 - 3.04 1.85 - 2.84 

Al Mean±SD 444±257 531±33 278±101 

Range 271 - 740 494 - 555 164 - 358 

As Mean±SD 12.79±2.98 7.24±0.57 7.44±1.58 

Range 9.97 - 15.9 6.59 - 7.57 6.39 - 9.26 

Ba 

Mean±SD 34.8±14.1 23.9±1.1 20.1±13.5 

Range 22.8 - 50.4 23.0 - 25.1 10.7 - 35.6 

Be 

Mean±SD 0.011±0.007 0.011±0.002 0.008±0.003 

Range 0.007 - 0.019 0.010 - 0.013 0.005 - 0.01 

Cd Mean±SD 0.805±0.460 0.590±0.019 1.124±0.808 

Range 0.434 - 1.32 0.569 - 0.605 0.559 - 2.05 

Co Mean±SD 2.62±0.74 2.36±0.13 1.82±0.78 

Range 2.16 - 3.48 2.21 - 2.44 0.95 - 2.44 

Cr Mean±SD 0.62±0.21 0.86±0.17 0.46±0.13 

Range 0.43 - 0.85 0.66 - 0.96 0.35 - 0.6 

Cu Mean±SD 238±83 156±8 135±25 

Range 176 - 333 147 - 160 108 - 158 

Fe 

Mean±SD 299±122 326±26 184±71 

Range 218 - 439 297 - 345 103 - 237 

Hg Mean±SD 0.052±0.007 0.071±0.009 0.104±0.076 

Range 0.045 - 0.059 0.063 - 0.08 0.053 - 0.191 

Mn 

Mean±SD 61.1±33.2 43.0±2.3 35.5±23.3 

Range 39.7 - 99.4 40.9 - 45.5 10.3 - 56.2 

Ni Mean±SD 3.11±2.09 2.56±0.17 1.81±0.66 

Range 1.7 - 5.51 2.37 - 2.69 1.05 - 2.2 

Pb Mean±SD 2.01±2.11 0.294±0.010 0.221±0.144 

Range 0.371 - 4.39 0.285 - 0.305 0.097 - 0.379 

Sb Mean±SD 0.025±0.008 0.015±0.002 0.014±0.004 

Range 0.02 - 0.034 0.013 - 0.016 0.009 - 0.017 

Tl Mean±SD 0.013±0.005 0.011±0.001 0.016±0.010 

Range 0.008 - 0.018 0.01 - 0.012 0.009 - 0.028 

V 

Mean±SD 2.13±1.18 2.58±0.21 1.70±0.47 

Range 1.3 - 3.48 2.34 - 2.73 1.16 - 2.02 

Zn 

Mean±SD 145±60 103±2 122.6±41.3 

Range 103 - 214 101 - 105 94.8 - 170 
134 

Table 3-29. Statistical comparison of metals concentrations in amphipods (Anonyx sp) from 

BSMP, Liberty, and Northstar in 2004, 2005, and 2006. Only metals for which 

statistically significant differences were detected are included. Differences were 

considered statistically significant for p-values  0.05 (Sokol and Rohlf, 1994) and are 

highlighted. 

Metal Source DF p-value Approach 

Ag – Rank 

Year 2 0.0217 Two-Way 

Location 2 0.0549 Two-Way 

Year x Location 3 0.6824 Two-Way 

Al – Log 

Year 2 0.0362 Two-Way 

Location 2 0.9723 Two-Way 

Year x Location 3 0.1378 Two-Way 

Be - Rank 

Year 2 <0.001 Two-Way 

Location 2 0.6945 Two-Way 

Year x Location 3 0.0818 Two-Way 

Co – Log 

Year 2 0.0023 Two-Way 

Location 2 0.3564 Two-Way 

Year x Location 3 0.0204 Two-Way 

Location x Year 7 0.0041 One-Way 

Cu – Rank 

Year 2 0.5339 Two-Way 

Location 2 0.0039 Two-Way 

Year x Location 3 0.1146 Two-Way 

Fe - Log 

Year 2 0.2842 Two-Way 

Location 2 0.7292 Two-Way 

Year x Location 3 0.0442 Two-Way 

Pb – Rank 

Year 2 0.0030 Two-Way 

Location 2 0.0054 Two-Way 

Year x Location 3 0.1759 Two-Way 

Sb 

Year 2 0.0003 Two-Way 

Location 2 0.9385 Two-Way 

Year x Location 3 0.0847 Two-Way 

V – Log 

Year 2 0.0082 Two-Way 

Location 2 0.9022 Two-Way 

Year x Location 3 0.1561 Two-Way 

 
135 

Figure 3-47. Concentrations of arsenic (As), barium (Ba), copper (Cu), and cadmium (Cd) in 

amphipods (Anonyx nugax) collected from nearshore waters of the Beaufort Sea 

between 1986 and 2006. Markers show the annual mean concentrations and lines show 

± 1 standard deviation. Markers with no lines have an SD that is smaller than the 

marker. From Neff et al. (2009). 

Concentrations of Cu and Zn in amphipods were the most uniform in the database with RSDs of 

25% and 20%, respectively, for the complete data set of 54 samples collected between 1999 and 

2006 (Table 3-30 and Figures 3-47 and 3-48). This uniformity for Cu and Zn is most likely due 

to ion regulation of these essential metals that helps control their concentrations in the 

amphipods. The other metals show a variety of values for the RSD that range from 26% for Ag 

and Co to 62% for Al (Table 3-30). Assuming that an increase of 2 standard deviations above the 

mean (for replicate samples) is required to identify changes in metal values, then a 40 to 52% 

increase in the absolute concentrations of Ag, Co, Cu and Zn would be needed to support a 

significant increase (Table 3-29). Similarly, increases in metal concentrations in amphipods of 64 

to 70% (2 SDs) would be needed to identify changes in concentrations of Mn, Sb, Tl, As and Ni 

(Table 3-30). 

1999 2000 2002 2004 2005 2006

0

4

8

12

16

A s (μg/g, dry weight)

A nonyx (amphipods)

1986 89 99 2000 02 04 05 06

0

20

40

60

80

B a (μg/g, dry weight)

A nonyx (amphipods)

1986 89 99 2000 02 04 05 06

0

100

200

300

Cu (μg/g, dry weight)

A nonyx (amphipods)

1986 89 99 2000 02 04 05 06

0.0

0.5

1.0

1.5

2.0

Cd (μg/g, dry weight)

A nonyx (amphipods)
136 

Figure 3-48. Concentrations of arsenic chromium (Cr), mercury (Hg), lead (Pb), and Zinc (Zn) 

in amphipods (Anonyx nugax) collected from nearshore waters of the Beaufort Sea 

between 1986 and 2006. Markers show the annual mean concentrations and lines show 

± 1 standard deviation. Markers with no lines have an SD that is smaller than the 

marker. From Neff et al. (2009). 

Because average metal concentrations for several metals were <1 μg/g, the absolute magnitude 

of any increase in metal values could be small, yet easily detected. For example, concentrations 

of Be ranged from 0.002 to 0.031 μg/g (i.e., 2 to 31 parts per billion) with a mean of 0.012 ± 

0.007 μg/g; thus, an increase of just 0.030 μg/g (30 parts per billion) would be equivalent to an 

increase of >4 standard deviations. 

3.3.1.3 120BBivalve Mollusks 

Bivalve mollusks, Astarte montagui, that occupies nearshore sandy marine sediments, and 

Cyrtodaria kurriana, that occupies fine grained sediment in river estuaries, were collected from 

several stations in the Liberty and BSMP areas in most years of the ANIMIDA and cANIMIDA 

Projects for analysis of tissue metals and hydrocarbons (Table 2-1). Because of difficulty in 

collecting sufficient tissue biomass of these small clams for metals and hydrocarbons analysis, 

relatively few tissue samples were available for metals analysis. Only a single sample of clams 

was available from Liberty in 2004 and 2005, and two samples were available in 2006. 

Concentrations of most metals, except Fe and Mn, were similar in clam and amphipod tissues 

(Table 3-25), and comparable to concentrations in bivalves from uncontaminated environments 

and the National Mussel Watch sites in the US and Europe (Tables 3-25 and 3-26). 

1999 2000 2004 2005 2006

0

1

2

3

4

5

Cr (μg/g, dry weight)

A nonyx (amphipods)

1999 2000 2002 2004 2005 2006

0.00

0.05

0.10

0.15

0.20

Hg (μg/g, dry weight)

A nonyx (amphipods)

1999 2000 2002 2004 2005 2006

0.0

0.2

0.4

0.6

0.8

1.0

P b (μg/g, dry weight)

A nonyx (amphipods)

1986 89 99 2000 02 04 05 06

0

50

100

150

200

Z n (μg/g, dry weight)

A nonyx (amphipods)
137 

Table 3-30. Means, standard deviations (SD), relative standard deviations [RSD = (mean/SD) x 

100], maximums and minimums for metals in 54 samples of amphipods (Anonyx) from 

the ANIMIDA and cANIMIDA study areas for combined data from 1999-2001, 2003 and 

2004-2006. 

Metal Mean ± SD 

(μg/g, dry wt.) 

RSD 

(%) 

Maximum 

(μg/g, dry wt.) 

Minimum 

(μg/g, dry wt.) (Max/Mean) 

Ag 2.5 ± 0.6 26 4.0 0.8 1.6 

Al 391 ± 242 62 1220 96 3.1 

As 9.4 ± 3.8 40 17.4 4.0 2.4 

Ba 26.1 ± 10.6 41 59.0 7.4 3.5 

Be 0.012 ± 0.007 57 0.031 0.002 2.6 

Cd 0.79 ± 0.45 57 2.4 0.3 3.0 

Co 1.7 ± 0.4 26 2.9 0.6 1.7 

Cu 149 ± 37 25 206 41 1.4 

Fe 293 ± 156 53 949 103 3.2 

Hg 0.067 ± 0.033 49 0.19 0.02 2.8 

Mn 40 ± 13 32 71 10 1.8 

Ni 2.9 ± 1.2 40 6.7 0.8 2.3 

Pb 0.23 ± 0.14 60 0.7 0.05 1.7 

Sb 0.022 ± 0.008 37 0.04 0.01 1.8 

Tl 0.011 ± 0.004 39 0.028 0.005 2.5 

V 1.6 ± 0.7 43 3.4 0.5 2.1 

Zn 105 ± 21 20 170 54 1.6 

% H2O 75.5 ± 2.3 3 80.0 71.0 1.06 

Clams from Liberty and the BSMP contained similar concentrations of most metals in 2004 and 

2005 (data for 2005 are summarized in Table 3-31). There were statistically significant 

differences between the two locations or among the three years for four metals in tissues of the 

clams (Table 3-32). The most significant difference (Pr>F = 0.0009) was for mercury 

(Table 3-33). The significant differences in concentrations of this metal and the other metals was 

caused by the small numbers of replicates and the narrow range of concentrations among 

replicates. All mercury concentrations and concentrations of the other metals were well below 

concentrations that could be toxic to the bivalves or their consumers, including man. 

Annual mean concentrations for eight of the 18 metals in clams (Astarte montagui) from the 

coastal Beaufort Sea are plotted with their respective standard deviations (square root of the 

variance) in Figures 3-49 and 3-50. Table 3-34 shows the grand means and standard deviations 

for the 1999-2006 data along with the relative standard deviations [RSD = (mean/SD) x 100], 

maximums and minimums. The 1999-2006 data sets were used to create Table 3-34 so that the 

same time interval would be used for all metals. As discussed above with the amphipod data, 

identification of any future changes in metal concentrations in clams relies on (1) a relatively low 

RSD or (2) low enough absolute metal values that changes can be distinguished before an 

adverse impact occurs. 
138 

Table 3-31. Concentrations of 18 metals in indigenous clams (Astarte montagui and Cyrtodaria 

kurriana) collected from two locations in the Beaufort Sea in 2005. n= number of 

samples. Concentrations are g/g dry wt (ppm). 

Metal Parameter 

Liberty 

(n= 1) 

BSMP 

(n= 5) 

Ag Mean±SD 0.066 0.085±0.031 

Range 0.052 - 0.137 

Al Mean±SD 1220 623±495 

Range 98.5 - 1320 

As Mean±SD 16 13.0±2.6 

Range 11.3 - 17.4 

Ba 

Mean±SD 24.8 17.3±13.0 

Range 7.9 - 39.5 

Be Mean±SD 0.085 0.046±0.020 

Range 0.019 - 0.066 

Cd Mean±SD 3.88 4.34±3.45 

Range 1.13 - 9.55 

Co Mean±SD 1.67 1.16±0.35 

Range 0.75 - 1.68 

Cr Mean±SD 3.7 2.46±1.60 

Range 0.91 - 5.15 

Cu Mean±SD 11.1 14.0±2.5 

Range 12.0 - 17.1 

Fe 

Mean±SD 1910 1227±592 

Range 771 - 2110 

Hg 

Mean±SD 0.081 0.042±0.007 

Range 0.030 - 0.047 

Mn 

Mean±SD 65.5 128±57.4 

Range 78.4 - 205 

Ni Mean±SD 4.45 4.05±1.27 

Range 2.04 - 5.34 

Pb Mean±SD 0.707 0.5274±0.426 

Range 0.184 - 1.24 

Sb Mean±SD 0.045 0.046±0.011 

Range 0.031 - 0.059 

Tl Mean±SD 0.021 0.022±0.006 

Range 0.015 - 0.030 

V 

Mean±SD 3.37 2.41±1.49 

Range 0.97 - 4.72 

Zn 

Mean±SD 73.1 70.8±9.2 

Range 57.8 - 79.3 
139 

Table 3-32. Statistical comparison of metals concentrations in clams (Astarte montagui and 

Cyrtodaria kurriana) from Liberty in 2004, 2005, and 2006 and the BSMP stations in 

2004 and 2005. Only metals for which statistically significant differences were detected 

are included. Differences were considered statistically significant for p-values  0.05 

(Sokol and Rohlf, 1994) and are highlighted. From Neff et al. (2009). 

Metal Source DF p-value Approach 

Co – Log 

Year 2 0.0220 Two-Way 

Location 1 0.0577 Two-Way 

Year x Location 1 0.3827 Two-Way 

Fe 

Year 2 0.0678 Two-Way 

Location 1 0.0392 Two-Way 

Year x Location 1 0.2692 Two-Way 

Hg 

Year 2 0.0868 Two-Way 

Location 1 0.0015 Two-Way 

Year x Location 1 0.0139 Two-Way 

Location_Year 4 0.0009 One-Way 

Mn – Log 

Year 2 0.0247 Two-Way 

Location 1 0.3780 Two-Way 

Year x Location 1 0.0570 Two-Way 

Table 3-33. Concentrations of mercury (Hg) in soft tissues of clams (Astarte montagui and 

Cyrtodaria kurriana) from Liberty and BSMP stations in 2004, 2005, and 2006. 

Concentrations are μg/g dry wt. (parts per million). Data from Neff et al. (2009). 

Year Liberty BSMP 

n Mean ± SD Range n Mean ± SD Range 

2004 1 0.075 0.075 3 0.067 ± 0.005 0.062 - 0.072 

2005 1 0.081 0.081 5 0.042 ± 0.007 0.030 - 0.047 

2006 2 0.068 ± 0.002 0.066 - 0.069 0 --- --- 

 
140 

Figure 3-49. Concentrations of arsenic (As). barium (Ba), copper (Cu), and cadmium (Cd) in 

clams from the coastal Beaufort Sea in 1986 through 2006. Markers show the annual 

mean concentrations and lines show ± 1 standard deviation. Markers with no lines 

have an SD that is smaller than the marker. From Neff et al. (2009). 

Figure 3-50. Concentrations of chromium (Cr), mercury (Hg), lead (Pb), and Zinc (Zn) in clams 

(Astarte montagui) collected from nearshore waters of the Beaufort Sea between 1986 

and 2006. Markers show the annual mean concentrations and lines show ± 1 standard 

deviation. Markers with no lines have an SD that is smaller than the marker. From 

Neff et al. (2009). 

1999 2000 2002 2004 2005 2006

0

5

10

15

A s (μg/g, dry weight)

A starte (clams)

1986 89 99 2000 02 04 05 06

0

10

20

30

40

B a (μg/g, dry weight)

A starte (clams)

1986 89 99 2000 02 04 05 06

0

10

20

30

Cu (μg/g, dry weight)

A starte (clams)

1986 89 99 2000 02 04 05 06

0

10

20

30

Cd (μg/g, dry weight)

A starte (clams)

1999 2000 2004 2005 2006

0

10

20

30

40

Cr (μg/g, dry weight)

A starte (clams)

1999 2000 2002 2004 2005 2006

0.00

0.04

0.08

0.12

Hg (μg/g, dry weight)

A starte (clams)

1986 89 99 2000 02 04 05 06

0.0

0.5

1.0

1.5

P b (μg/g, dry weight)

A starte (clams)

1986 89 99 2000 02 04 05 06

0

50

100

Z n (μg/g, dry weight)

A starte (clams)
141 

Table 3-34. Means, standard deviations (SD), relative standard deviations [RSD = (mean/SD) x 

100], maximums and minimums for metals in 22 samples of clams (Astarte montagui and 

Cyrtodaria kurriana) from the ANIMIDA and cANIMIDA study areas for combined data 

from 1999-2001, 2003 and 2004-2006. 

Metal 

Mean ± SD 

(μg/g, dry wt.) 

RSD 

(%) 

Maximum 

(μg/g, dry wt.) 

Minimum 

(μg/g, dry wt.) (Mean/Min) 

Ag 0.07 ± 0.02 32 0.13 0.04 1.8 

Al 1000 ± 454 45 2150 98 2.2 

As 11.2 ± 2.1 19 16 8 1.4 

Ba 17.2 ± 7.2 42 40 7 2.3 

Be 0.052 ± 0.015 29 0.085 0.029 1.6 

Cd 7.9 ± 3.1 39 13.1 0.5 1.6 

Co 2.1 ± 1.0 47 4.0 0.8 1.9 

Cu 13.0 ± 3.6 28 24 7 1.8 

Fe 1555 ± 672 43 3640 771 2.3 

Hg 0.060 ± 0.021 35 0.127 0.025 2.1 

Mn 235 ± 163 69 637 47 2.7 

Pb 0.62 ± 0.22 35 1.2 0.2 1.9 

Sb 0.034 ± 0.015 43 0.059 0.010 1.7 

Tl 0.018 ± 0.006 33 0.028 0.008 1.6 

V 3.4 ± 1.4 42 6.9 1.3 2.0 

Zn 79.9 ± 14.1 18 125 62 1.6 

% H2O 84.4 ± 2.9 3.5 92 78 1.18 

Concentrations of As, Cu and Zn in clams were the most uniform in the data base with RSDs of 

19%, 28% and 18%, respectively, for the complete data set of 22 samples collected between 

1999 and 2006 (Table 3-34 and Figures 3-49 and 3-50). The other metals show a variety of 

values for the RSD that range from 29% for Be and Co to 69% for Mn (Table 3-34). If an 

increase of 2 standard deviations above the mean (for replicate samples) is assumed to be 

required to support a change in metal values, then a 36 to 58% increase in the absolute 

concentrations of As, Be, Cu and Zn would be needed to identify a significant increase 

(Table 3-34). Similarly, increases in metal concentrations in clams of 64 to 70% would be 

needed to identify changes in concentrations of Ag, Hg, Pb and Tl (Table 3-34). 

Because average concentrations for several metals are <1 μg/g, the absolute magnitude of any 

increase in metal values could be small, yet easily detected. For example, concentrations of Ag 

ranged from 0.04 to 0.13 μg/g with a mean of 0.07 ± 0.02 μg/g; thus, an increase of just 0.10 

μg/g (100 parts per billion) would be equivalent to an increase of >5 standard deviations. 

3.3.1.4 12BDeployed Mussels 

Concentrations of 18 metals were measured in soft tissues of the zero-time reference mussels 

(Mytilus trossulus) (from a mariculture facility in Port Chatham, AK, near the entrance to Cook 

Inlet) and mussels that had been deployed for approximately two weeks near the Northstar 
142 

Development, the Liberty prospect, and at BSMP stations in 2004, 2005, and 2006. Mussels also 

were deployed at Prudhoe Bay in 2005 and at the Endicott SDI (where slant drilling into the 

Liberty prospect is planned) and West Dock in 2006 (Table 3-33). Concentrations of most of the 

metals were higher in mussels that had been deployed for about two weeks in the Beaufort Sea 

than in zero-time reference mussels. Table 3-35 summarizes metals concentrations in reference 

(time zero) and deployed mussels in 2006). 

Concentrations of most metals in zero time reference mussels were similar in 2004, 2005, and 

2006 (Figure 3-51). Interannual differences rarely were more than two-fold. Largest differences 

were for abundant metals, such as Fe and Mn. Thus, the zero time mussels serve as a good 

reference for the mussels that were deployed at locations in the Beaufort Sea. 

Mussels were deployed at Liberty, Northstar, and BSMP in 2004, 2005, and 2006, so statistical 

comparisons can be made for all 18 metals in mussels deployed in three years and in three 

locations. There were statistically significant differences in concentrations of nine metals in the 

three years of the study: Ag, As, Cd, Co, Mn, Ni, Pb, and V (Table 3-36). Significant differences 

also were observed for Mn and Tl for location and year x location and for Ni for year x location. 

None of the differences in metal concentrations in mussels deployed in 2004, 2005, and 2006 at 

BSMP, Liberty, and Northstar were large. 

Ag and Pb concentrations were significantly higher in deployed mussels in 2004 than in 2005 

and 2006; As and Cd concentrations were lower in 2004 than in 2005 and 2006. V concentration 

was higher in 2005 than in 2004 and 2006. Co, Mn, and Ni concentrations were significantly 

higher in mussels deployed at BSMP in 2006 than in mussels deployed at other locations and 

years. Hg and Tl concentrations were very low in all mussels, but concentrations varied among 

years and deployment locations. 

Twelve metals (Ag, As, Ba, Be, Cd, Cu, Fe, Hg, Pb, Tl, V, and Zn) were measured in the soft 

tissues of reference mussels and mussels deployed near the Northstar Development as part of 

Task 2 of the ANIMIDA Project (Brown et al., 2005). These 12 metals and an additional six 

metals were analyzed in mussels in 2004 through 2006 as part of the cANIMIDA Project. 

Concentrations of Ba, Be, Cu, Fe, and Zn were higher in reference mussels and mussels that had 

been deployed at the Northstar Development in 2002 than in 2004, 2005, and 2006 (Table 3-37). 

Concentrations of Ag and As were slightly lower in mussels deployed at the Northstar 

Development in 2002 than in those deployed there in 2004, 2005, and 2006. In all cases, the 

differences were small and the number of replicates in each year was small, indicating that the 

differences were not ecologically significant. In each year, the concentration of each metal was 

similar in reference mussels and mussels that were deployed at the Northstar Development, 

indicating the metals were accumulated primarily at the reference site, Port Chatham. 

 
143 

Table 3-35. Concentrations of 18 metals in Mussels (Mytilus trossulus) following deployment in 

five regions of the Beaufort Sea, compared to the time zero reference animals in 2006. n= 

number of samples. Concentrations are μg/g dry wt. From Neff et al. (2009). 

Metal Parameter Liberty 

(n= 3) 

Northstar 

(n= 2) 

BSMP 

(n= 1) 

SDI 

(n= 1) 

West Dock 

(n= 1) 

Time Zero

(n= 1) 

Ag Mean±SD 0.075±0.010 0.065±0.004 0.103 0.069 0.05 0.07 

Range 0.064-0.081 0.062-0.067 

Al Mean±SD 1182±448 328±74.2 1910 1860 1690 474 

Range 665-1450 275-380 

As Mean±SD 10.9±0.2 8.97±0.47 11.7 10.8 10.1 10.8 

Range 10.8-11.1 8.63-9.30 

Ba Mean±SD 10.4±2.86 3.34±0.59 8.72 17.9 14.4 3.75 

Range 7.09-12.1 2.92-3.76 

Be Mean±SD 0.028±0.005 0.012±0.004 0.021 0.038 0.038 0.011 

Range 0.022-0.032 0.009-0.014 

Cd Mean±SD 4.23±0.22 3.14±0.37 5.27 4.16 3.72 4.07 

Range 3.98-4.39 2.88-3.4 

Co Mean±SD 0.87±0.08 0.556±0.062 1.56 1.2 1.08 0.803 

Range 0.77-0.93 0.512-0.599 

Cr Mean±SD 2.32±0.49 1.19±0.11 7.32 4.17 3.24 2.09 

Range 1.75-2.64 1.11-1.27 

Cu Mean±SD 7.3±0.6 5.75±0.49 7.4 7.9 8.2 6 

Range 6.9-8.0 5.4-6.1 

Fe Mean±SD 976±273 424±81 2010 1790 1470 659 

Range 669-1190 366-481 

Hg Mean±SD 0.095±0.006 0.062±0.003 0.104 0.112 0.121 0.086 

Range 0.091-0.102 0.06-0.064 

Mn Mean±SD 18.0±3.9 13±2.8 61.5 29.8 29.6 21.3 

Range 13.8-21.4 11-15 

Ni Mean±SD 2.08±0.33 1.63±0.08 4.94 3.4 3.12 2.1 

Range 1.70-2.33 1.57-1.68 

Pb Mean±SD 0.697±0.170 0.457±0.030 0.795 0.933 0.631 0.587 

Range 0.513-0.849 0.435-0.478 

Sb Mean±SD 0.007±0 0.011±0.030 0.011 0.011 0.013 0.005 

Range 0.007-0.007 0.009-0.013 

Tl Mean±SD 0.016±0.004 0.009±0.002 0.019 0.024 0.011 0.012 

Range 0.012-0.019 0.007-0.01 

V Mean±SD 4.06±1.39 1.88±0.24 6.74 5.27 4.48 2.98 

Range 2.68-5.46 1.71-2.05 

Zn Mean±SD 103.6±9.05 91.9±6.0 95 110 105 85.9 

Range 97.9-114 87.6-96.1 
144 

Figure 3-51. Mean metals concentrations in reference mussels collected at Port Chatham in 

2004, 2005, and 2006. Note that the y-axis is log scale. From Neff et al. (2009). 

3.3.1.5 12BIntegration of Metals Concentrations in Tissues of Indigenous Marine Animals 

and Deployed Mussels in the Beaufort Sea 

Concentrations of 18 metals in tissues of several species of fish, amphipods, isopods, and clams 

collected near the Northstar Development, in the Liberty Prospect area, and in other reference 

areas were similar in 2004, 2005, and 2006, and comparable to metals concentrations in the same 

species collected in the ANIMIDA Project. When statistically significant differences were 

detected among years or locations, the differences were small. Northstar is the only offshore area 

where a large amount of development drilling has occurred and where oil production currently is 

occurring. A few metals concentrations were higher in marine animals from Northstar than in 

the same species from the other sampling sites (Pb in amphipods and Ag and Cu in fish); 

however, there were no consistent differences by year or location. 

Although there were interannual differences in concentrations for several metals, the differences 

were small and all concentrations were in the range for marine animals from clean marine 

environments (Table 3-26). Concentrations of most metals were higher in clams and mussels 

than in amphipods and fish. Aluminum and iron concentrations tended to be higher in clams than 

in crustaceans and fish, possibly indicating that the clams are retaining sediment particles in the 

gut and gills. 

0.001

0.01

0.1

1

10

100

1000

Ag Al As Ba Be Cd Co Cr Cu Fe Hg Mn Ni Pb Sb Tl V Zn

Metal

2004

2005

2006

Metals Concentrations in

Zero Time Mussels - 2004-6
145 

Table 3-36. Statistical comparison of metals concentrations in mussels (Mytilus trossulus) that 

were deployed at BSMP, Liberty, and Northstar in 2004, 2005, and 2006. Only metals for 

which statistically significant differences were detected are included. Differences were 

considered statistically significant for p-values  0.05 (Sokol and Rohlf, 1994) and are 

highlighted. From Neff et al. (2009). 

Metal Source DF F Value p-value 

Ag 

Year 2 5.65 0.0187 

Location 3 2.93 0.0770 

Year x Location 6 2.00 0.1451 

As 

Year 2 13.20 0.0009 

Location 3 0.37 0.7758 

Year x Location 6 2.46 0.0871 

Cd 

Year 2 30.10 <0.0001 

Location 3 0.56 0.6540 

Year x Location 6 2.12 0.1266 

Co – Rank 

Year 2 4.55 0.0339 

Location 3 0.28 0.8406 

Year x Location 6 6.88 0.0024 

Hg 

Year 2 2.56 0.1183 

Location 3 1.46 0.2755 

Year x Location 6 6.84 0.0024 

Mn – Log 

Year 2 6.76 0.0108 

Location 3 4.47 0.0251 

Year x Location 6 3.25 0.0392 

Ni – Rank 

Year 2 4.00 0.0466 

Location 3 0.61 0.6241 

Year x Location 6 3.15 0.0428 

Pb 

Year 2 4.60 0.0329 

Location 3 0.23 0.8755 

Year x Location 6 095 0.4971 

Tl 

Year 2 13.29 0.0009 

Location 3 7.50 0.0044 

Year x Location 6 3.87 0.0220 

V 

Year 2 13.72 0.0008 

Location 3 1.66 0.2285 

Year x Location 6 2.94 0.0528 
146 

Table 3-37. Mean (± Sd) concentrations of 12 metals in tissues of reference mussels from Port 

Chatham, AK, and mussels from Port Chatham that had been deployed for 2 to 3 weeks 

near the Northstar Development in 2002 (ANIMIDA Project), 2004, 2005, and 2006 

(cANIMIDA Program). n= number of samples. Concentrations are μg/g dry wt. From 

Neff et al. (2009). 

Metal Reference Mussels Mussels Deployed at Northstar 

 2002 

(n = 2) 

2004 

(n = 3) 

2005 

(n = 2) 

2006 

(n = 1) 

2002 

(n = 2) 

2004 

(n = 3) 

2005 

(n = 1) 

2006 

(n = 2) 

Ag 0.08±0.01 0.09±0.01 0.08±0.01 0.07 0.08±0.01 0.12±0.02 0.09 0.06±0.00 

As 6.9±0.6 8.4±1.4 12.4±1.1 10.8 6.7±0.10 10.2±1.11 11.3 8.97±0.47 

Ba 18±3 5.2±3.5 6.0±0.70 3.75 17±2 13.0±5.7 7.2 3.34±0.59 

Be 0.04±0.01 0.01±0.01 0.01±0.01 0.01 0.04±0.00 0.03±0.01 0.02 0.01±0.00 

Cd 3.9±0.4 2.4±0.71 4.69±1.05 4.07 3.9±0.30 2.32±1.51 4.77 3.14±0.37 

Cu 9.9±1.4 7.0±1.3 7.9±0.40 6.0 9.1±0.10 8.3±0.97 7.0 5.75±0.49 

Fe 1300±80 374±265 460±0.7 659 1370±130 865±341 265 424±81 

Hg 0.11±0.01 0.10±0.01 0.05±0.00 0.09 0.09±0.01 0.09±0.01 0.25 0.06±0.00 

Pb 0.75±0.10 0.88±0.33 0.61±0.02 0.59 0.71±0.05 0.99±0.11 0.52 0.46±0.03 

Tl 0.02±0.004 0.01±0.00 0.02±0.00 0.01 0.02±0.00 0.02±0.00 0.04 0.01±0.00 

V 4.2±0.01 1.67±1.15 1.11±0.06 2.98 4.0±0.50 3.65±0.94 0.99 1.88±0.24 

Zn 114±4 99.7±33.7 101±2.0 85.9 106±2.0 93.3±34.2 95.6 91.9±6.0 

There were no consistent trends in concentrations of metals in fish tissues. Demersal species, 

such as four horn sculpin, tended to contain higher concentrations of metals than the more 

pelagic species. The anadromous species, such as arctic char, tended to contain lower 

concentrations of metals than the other species did, perhaps because they spend much of the year 

in fresh water where dissolved concentrations of most metals are lower than in the ocean. 

The concentrations of metals in the tissues of most of the bivalve mollusks, crustaceans, and fish 

sampled in this project were in the range expected for the same or similar species in relatively 

unpolluted marine environments throughout the world (Table 3-26). Concentrations of different 

metals vary widely in tissues of different taxa of marine animals. Zinc is particularly abundant in 

mollusks (particularly oysters); copper often is abundant in crustaceans and oysters. Mercury 

tends to be more abundant in fish tissues, particularly muscle, than in tissues of marine 

invertebrates. Most of the mercury in fish muscle is methylmercury. This pattern of distribution 

of metals was evident in bivalve mollusks, crustaceans, and fish in the Alaskan Beaufort Sea. 

The National Status and Trends Mussel Watch Program median metals concentrations in mussels 

and oysters can be considered normal values (Table 3-25). A few fish, mussel, amphipod, and 

clam samples from the Beaufort Sea contained higher than the NS&T median concentrations of 

the 8 metals for which median NS&T values are available. As expected, amphipods contained 

copper at concentrations that exceeded the median value for copper in mussels, but not oysters. 

Crustaceans often contain naturally high concentrations of copper in their blood pigment. As 

discussed above, fish muscle often contains slightly elevated concentrations of mercury, as 

methylmercury. Some fish collected in the Beaufort Sea contained greater than the mussel 
147 

median value for mercury of 0.24 g/g. The mercury concentration in Beaufort Sea fish is well 

below the 1 g/g wet wt (~ 5 μg/g dry wt) screening concentration for edible tissues of fishery 

products consumed by man set by the Food and Drug Administration (FDA, 2001). Most marine 

fish from elsewhere contain mercury concentrations similar to or higher than concentrations 

reported in this investigation for Beaufort Sea fish. These concentrations of metals in tissues are 

not harmful to the animals themselves or to consumers of these species, including man. 

3.3.2 60BHydrocarbons in Tissues of Marine Animals 

3.3.2.1 123BPAH in Fish Tissues 

A total of 171 fish were collected 2004, 2005, and 2006 in the Northstar, Liberty, and the BSMP 

areas for chemical and biomarker analysis (Table 2-1). An additional 125 fish were collected in 

2001 as part of the ANIMIDA Project. A total of 28 fish samples of seven species were analyzed 

in 2004, 21 samples of six species were analyzed in 2005, and 20 samples of five species were 

analyzed in 2006. 

TPAH concentrations in fish tissues varied widely among both locations and years (Table 3-38). 

Mean TPAH concentrations in all species combined were higher at both Northstar and Liberty in 

2001 than in 2004 through 2006. Mean TPAH concentrations in all species combined were 

highest at Liberty in 2001 (64.1 ± 65.9 ng/g dry wt) and lowest at Northstar in 2005 (9.44 ± 6.85 

ng/g). TPAH concentrations in tissues of all eight species of fish combined were lower in 2005 

than in 2001, 2004, and 2006. The same pattern was observed for TPAH and all other 

hydrocarbon concentrations in crustaceans, indigenous clams, and deployed mussels 

(Table 3-38). These differences may have been caused by analytical error or natural interannual 

variation in hydrocarbon concentrations in the environment. 

TPAH concentrations were quite variable in the eight species of fish sampled (Table 3-38). 

Arctic cod, an important food web species, contained higher concentrations of TPAH than the 

other species collected at Northstar and Liberty in 2004. Arctic cod were not collected in 2005 

and 2006, and four horn sculpin, a demersal species, usually contained the highest TPAH 

concentrations. 

The PAH assemblage in all fish samples was dominated by naphthalene and alkyl naphthalenes, 

sometimes with smaller amounts of phenanthrenes (Figure 3-52). Fish have an inducible enzyme 

system, the cytochrome P450 mixed function oxygenase that efficiently metabolizes PAH. 

CYP1A metabolizes higher molecular weight PAH more efficiently than low molecular weight 

PAH; this may explain the relative abundance of 2- and 3-ring PAH and the low concentrations 

of TPAH in fish tissues. In all years, the PAH profile in fish tissues is indicative of a primarily 

petrogenic source, but this pattern is obscured somewhat by the preferential metabolism of 

higher molecular weight, pyrogenic PAH. The fish tissue PAH residue data for 2001 through 

2006 also are consistent with chronic, low-level exposure to PAH in water, sediments, and food 

throughout the study area, with no clear point source of bioavailable PAH in the coastal 

environment. 

 
148 

Table 3-38. Mean Concentrations of total polycyclic aromatic hydrocarbons, dibenzothiophenes, 

and dibenzofuran (TPAH), total saturated hydrocarbons (TSHC), pristane, and 

steranes/triterpanes (StTr) in tissues of indigenous fish, clams, amphipods, isopods, and 

mysids collected at several locations in the Alaskan Beaufort Sea in 2004 through 2006. 

From Neff et al. (2009). 

Taxon Analytes Location Mean (SD) Concentration (ng/g) 

2004 2005 2006 

Fish 

(8 species) TPAH 

Northstar 38.8 ± 20.7 9.44 ± 6.85 52.4 ± 12.8 

Liberty 47.8 ± 25.3 10.1 ± 6.45 24.8 ± 6.4 

Tigvariak Island 30.4 ± 7.7 No data No data 

Amphipods 

TPAH 

Northstar 83.3 ± 52.7 13.8 ± 8.96 41.3 ± 27.4 

Liberty 73.6 ± 10.3 39.5 ± 10.1 81.5 ± 23.9 

BSMP 49.5 ± 16.7 23.6 ± 9.24 60.9 ± 14.4 

TSHC 

Northstar 31,458 ± 2784 18,003 ± 1746 26,681 ± 17,987 

Liberty 26,203  2010 44,625 ± 14,523 85,152 ± 41,029 

BSMP 28,704 ± 3948 26,914 ± 9980 43,679 ± 31,008 

Pristane 

Northstar 26,968 ± 3237 16,598 ± 8736 24,749 ± 18,785 

Liberty 24,634 ± 2488 42,127 ± 17,377 81,071 ± 47,234 

BSMP 27,254 ± 5160 24,644 ± 14,816 39,986 ± 3397 

StTr 

Northstar 12.7 ± 4.37 0.57 ± 0.25 1.09 ± 2.40 

Liberty 8.10 ± 0.40 4.88 ± 2.27 8.38 ± 6.53 

BSMP 3.70 ± 1.93 0.52 ± 0.32 13.4 ± 17.8 

Isopods TPAH 

Northstar No data No data 67.6 ± 12.8 

Liberty No data 67.0 ± 9.83 88.5 

BSMP No data 73.37 ± 4.36 114 

Mysids TPAH Northstar No data No data 89.3 ± 24.4 

Clams 

TPAH Liberty 91.85 No data 141 ± 57.8 

BSMP 97.1 ± 52.5 38.4 ± 12.3 No data 

TSHC Liberty 1644 No data 5276 ± 666 

BSMP 1922 ± 621 1510 ± 634 No Data 

Pristane Liberty 80.2 No data 96.6 ± 36,0 

BSMP 152 ± 40.6 434 ± 629 No data 

StTr Liberty 8.99 No data 0 

BSMP 8.40 ± 6.20 1.72 ± 2.98 No data 
149 

Figure 3-52. Profiles of mean concentrations of individual PAH in tissues of fish from Northstar 

and Liberty collected in 2006. From Neff et al. (2009).

3.3.2.2 124BExposure Biomarkers in Fish Tissues 

CYP1A staining in fish tissues. Several species of fish from Liberty and Northstar were 

analyzed by immunohistochemistry for CYP1A activity in 2004 and 2006. Several fish tissues 

stained for CYP1A but there were significant differences in staining intensity only in hepatocytes 

of some species (Table 3-39). Highest CYP1A staining scores in hepatocytes were in Arctic 

cisco from Liberty in 2004 and in humpback broad whitefish and four horn sculpin in 2005. All 

scores were low (2 or lower with a test score range of 0 to 15). 

Fish tissues from 5 sites (2 sites near Northstar, 2 near Liberty, and 1 reference site east of 

Liberty) were stained for CYP1A activity in 2001(Spies et al., 2003). There was low to moderate 

staining of hepatocytes and gut mucus epithelium, but not other tissues, in most fish from all 5 

sites. Hepatocyte staining scores were highest in four horn sculpin from Point Brower (near 

Liberty) and Stump Island (near Northstar). Staining scores in gut mucous epithelium were 

highest in four horn sculpin from Point Brower and Bullen Point (reference site). Highest mean 

staining score was in gut mucous epithelium of four horn sculpin from Point Brower (mean score 

~ 6.0). CYP1A staining intensity in arctic cod hepatocytes was correlated to concentrations of 

PCBs in whole fish tissues. CYP1A staining intensity in four horn sculpin gut mucus epithelium 

was correlated to concentrations of total low molecular weight PAH in the whole fish tissues. 

There were no other statistically significant correlations. 

0

2

4

6

8

10

12

14

N

C1NC2NC3NC4N

BIP

ACEACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaA

C

C1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

PAH Concentration (ng/g dry)

Northstar TPAH = 49 ng/g

Liberty TPAH = 21 ng/g
150 

Table 3-39. Immunohistochemical staining for CYP1A of hepatocytes of fish collected in 2004 

at three Liberty, Northstar, and Tigvariak Island (reference site) and in 2005 at Liberty and 

Northstar. Scaled score range is 0 – 15. n = number of samples. From Neff et al. (2009). 

Fish Species Station Tissue 

CYP1A Staining 

Sig. Diff. 

n 

Mean Scaled 

Score ± SD 

2004 

Arctic cisco Liberty Hepatocyte 3 2.00 ± 0.87 Liberty > Northstar Northstar Hepatocyte 8 0.0 

Least cisco 

Liberty Hepatocyte 5 0.60 ± 0.82 

Liberty > Tigvariak, 

Northstar Northstar Hepatocyte 8 0.0 

Tigvariak Hepatocyte 7 0.0 

Arctic cod 

Northstar Hepatocyte 4 0.0 

Liberty Hepatocyte 3 0.0 NS 

Tigvariak Hepatocyte 6 0.17 ± 0.41 

Four Horn Sculpin Liberty Hepatocyte 6 0.50 ± 1.22 NS Tigvariak Hepatocyte 10 1.50 ± 1.87 

2005 

Humpback broad 

whitefish 

Northstar Hepatocyte 9 1.5 ± 1.3 Northstar > Liberty Liberty Hepatocyte 7 0.21 ± 0.57 

Four horn sculpin Northstar Hepatocyte 2 1.5 ± 2.1 NS 

Liberty Hepatocyte 1 3.0 

NS, no significant difference.

The CYP1A staining data for 2001, 2004, and 2005 are consistent in showing low-level staining 

in several fish tissues, with no significant trends among fish species or sampling locations. Fish 

throughout the ANIMIDA study area apparently are being exposed to very low levels of 

CYP1A-inducing chemicals, possibly of several types and sources, including petroleum PAH 

and several organochlorine compounds (Spies et al., 2003). 

Fluorescent aromatic compounds (FACs) in fish bile. When fish metabolize PAH and certain 

other nonpolar organic compounds, the polar metabolites are complexed with soluble compounds 

and excreted in the bile. The PAH metabolites are aromatic and fluoresce strongly at 

wavelengths characteristic of different conjugated aromatic structures. Thus, concentrations of 

fluorescent aromatic compounds (FACs) in bile are good biomarkers of exposure of fish to PAH 

in the water or food. Two-ring (e.g., naphthalenes), three-ring (e.g., phenanthrenes), and fourthrough six-ring PAH metabolites (e.g., benzo(a)pyrene) fluoresce at different wavelengths and 

usually are quantified as naphthalene equivalent, phenanthrene equivalent, and benzo(a)pyrene 

equivalent FACs. 
151 

Figure 3-53. Mean and SD concentrations of fluorescent aromatic compounds (FACs) in bile of 

fish collected in three areas in the Beaufort Sea in 2004 (top) in the Northstar and 

Liberty areas in 2005 (bottom). Concentrations of naphthalene, phenanthrene, and 

benzo(a)pyrene equivalents are ng/μg bile protein (= μg/mg protein). 

0

5

10

15

20

25

30

35

40

45

Naphthalene Phenanthrene Benzo(a)pyrene

Equivalents (ng/ug protein)

Liberty

Northstar

Tigvariak

Bile FACs in Fish - 2004

0

5

10

15

20

25

30

35

Naphthalene Phenanthrene Benzo(a)pyrene

Equivalents (ng/ug protein)

Liberty

Bile FACs in Fish - 2005 Northstar
152 

Concentrations of FACs were low in most of the 56 fish bile samples analyzed in 2004 

(Figure 3-53). The protein-normalized metabolite concentrations have a much smaller range of 

variation, particularly for samples that have relatively higher naphthalene-equivalent metabolite 

concentrations. The protein-normalized naphthalene-equivalent concentrations ranged from 1.9 

to 57 μg/mg protein. Normalized values for phenanthrene and benzo(a)pyrene (BaP) equivalents 

ranged from 0.14 to 77 μg/mg protein and 0.01 to 0.23 μg/mg protein, respectively 

(Figure 3-51). 

Concentrations of naphthalene-equivalent and phenanthrene-equivalent bile FACs were lower in 

most of the 30 fish bile samples analyzed in 2005 than in those analyzed in 2004 (Figure 3-53). 

BaP-equivalent concentrations in bile of fish collected in 2005 were slightly higher than in bile 

of 2004 fish. Protein-normalized naphthalene-equivalent bile FACs ranged from 0.8 to 36.2 μg/g 

protein, normalized phenanthrene equivalents ranged from 0.1 to 5.2 ng/μg protein, and BaP 

equivalents ranged from 0.03 to 0.38 μg/g protein. There was not a significant difference in 

concentrations of the three bile FACs concentrations in fish from Liberty and Northstar. As with 

the 2004 FAC data, the protein-normalized bile FAC concentrations in fish collected near 

Northstar and Liberty in 2005 were similar to bile FAC concentrations in fish from contaminated 

and clean marine areas of the Pacific Northwest (Meador et al., 2008; Myers et al., 2008). 

Phenanthrene-equivalent and BaP-equivalent bile FACs were measured in 57 samples of bile 

from 5 species of fish collected in 2001 at 5 locations in the Beaufort Sea as part of Task 8 of the 

ANIMIDA Project (Spies et al., 2003). FAC concentrations were not normalized to bile protein. 

Mean concentrations of phenanthrene-equivalent and BaP-equivalent FACs ranged from 0.05 to 

12 μg/g and 0.02 to 0.32 μg/g, respectively, in the different fish species. The highest mean 

phenanthrene-equivalent FAC concentration was in arctic cod from Liberty; the highest mean 

BaP-equivalent FAC concentration was in arctic cisco from Stump Island (between Northstar 

and West Dock). Both phenanthrene-equivalent and BaP-equivalent bile FAC concentrations in 

Beaufort Sea fish were lower in 2001 than in 2004 and 2005. The bile FAC data for the 3 years 

indicate that fish in coastal waters of the Beaufort Sea development area are being exposed to 

low concentrations of low and high molecular weight PAH. 

3.3.2.3 125BHydrocarbons in Tissues of Indigenous Clams, Amphipods, Isopods, and Mysids 

Soft tissues of clams (Astarte montagui and Cyrtodaria kurriana) and amphipods (Anonyx 

nugax) collected at different locations in the Beaufort Sea during cANIMIDA in 2004, 2005, and 

2006 were analyzed for PAH, saturated hydrocarbons (SHC), and sterane/triterpane biomarkers 

(StTr). Isopods (Saduria sabini) and mysids (Mysis sp) were collected opportunistically and were 

analyzed for PAH. 

PAH. Indigenous clams (Astarte montagui and Cyrtodaria kurriana) and three taxa of 

crustaceans (amphipods, isopods, and mysids) collected at Liberty, Northstar, and at reference 

stations contained similar concentrations of TPAH in any one year of the project, with lowest 

concentrations in all species in 2005 (Table 3-38). As expected, mean TPAH concentrations in 

whole fish tissues were lower each year than in the four taxa of marine invertebrates, because of 

the greater ability of fish than mollusks and crustaceans to metabolize and excrete PAH (Neff, 

2002a). The mean TPAH concentration in amphipods from Liberty was higher than that in 

amphipods from Northstar in 2005; the mean TPAH concentration was significantly higher in 

amphipods from Liberty than in those from BSMP and Northstar in 2006 (Table 3-38). 
153 

The PAH assemblage in amphipods, isopods, mysids, and clams was dominated by 

alkylnapthalenes and alkylphenanthrenes, consistent with a predominantly petroleum source for 

the PAH in the invertebrate tissues (Figures 3-54 and 3-55). The most abundant five- through 

six-ring PAH in tissues of all four taxa was perylene, a predominantly biogenic PAH derived 

from diagenesis of organic matter of plant origin in anoxic sediments (Venkatesan, 1988). This 

may indicate that eroding coastal peat (high in perylene) may be important in the food web 

leading to these mollusks and crustaceans. 

Figure 3-54. The PAH profile in tissues of amphipods and isopods collected at BSMP, Liberty, 

and Northstar in 2006. From Neff et al. (2009). 

0

2

4

6

8

10

12

14

16

18

N

C1NC2NC3NC4N

BIP

ACE

ACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaA

C

C1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

Concentration (ng/g)

BSMP

Liberty

Northstar

PAH in Amphipods Collected in 2006

0

2

4

6

8

10

12

14

16

18

20

N

C1NC2NC3NC4N

BIP

ACE

ACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaA

C

C1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

Concentration (ng/g)

BSMP

Liberty

Northstar

PAH in Isopods Collected in 2006
154 

Figure 3-55. The PAH profile in tissues of mysids collected at Northstar (top) and clams 

collected at Liberty (bottom) in 2006. From Neff et al. (2009). 

SHC. The saturated hydrocarbon data yielded some information that, with the TPAH and St/Tr 

data, was useful in the food chain conceptual model that was developed as part of this task. Total 

SHC concentrations were very high in tissues of amphipods, clams, and deployed mussels 

(Tables 3-38 and 3-40). Most of the SHC in amphipods, but not in clams or deployed mussels, 

was a single isoprenoid hydrocarbon, pristane. Pristane is present in petroleum, but its main 

source in the marine environment is from zooplankton, particularly copepods of several genera, 

including Neocalanus and Pseudocalanus, the dominant zooplankton in Beaufort Sea waters in 

most seasons (Horner and Murphy, 1985). 

0

2

4

6

8

10

12

14

N

C1NC2NC3NC4N

BIP

ACE

ACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaA

C

C1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

Concentration (ng/g)

PAH in Mysids Collected at Northstar in 2006

0

2

4

6

8

10

12

N

C1NC2NC3NC4N

BIP

ACE

ACY

F

C1FC2FC3F

A

P

C1PC2PC3PC4P

DBT

C1DBTC2DBTC3DBT

FLU

PYR

C1FLU/PYRC2FLU/PYRC3FLU/PYR

BaA

C

C1CC2CC3CC4C

BbFLU

BkFLU

BePBaP

PER

IcdPYR

DBahA

BghiP

Concentration (ng/g)

PAH in Clams Collected at Liberty in 2006
155 

Table 3-40. Concentrations of total PAH, total SHC, and total St/Tr in amphipods (Anonyx 

nugax) sampled at 23 sites in 5 monitoring areas in 2006. n = number of samples. 

Concentrations are ng/g dry wt. From Neff et al. (2009). 

Hydrocarbon n Location Mean SD Range 

Total PAH 

2 Liberty 92.2 26.6 73.4 – 111 

10 Northstar 41.3 27.4 19.7 – 114 

2 West Dock 103 19.6 83.6 – 123 

2 Boulder Patch 70.9 16.5 54.4 – 87.4 

7 BSMP 60.9 14.4 34.8 – 80.1 

Total SHC 

2 Liberty 66,400 37,700 39,700 – 93,100 

10 Northstar 33,800 20,100 13,700 – 71,700 

2 West Dock 25,900 732 25,200 – 26,700 

2 Boulder Patch 145,500 8,300 137,000 – 154,000 

7 BSMP 90,800 77,600 26,100 – 249,000 

Pristane 

2 Liberty 48,100 36,600 22,300 – 74,000 

10 Northstar 24,700 18,800 6,400 – 61,000 

2 West Dock 15,600 1,020 14,600 – 16,600 

2 Boulder Patch 114,000 22,600 91,400 – 136,600 

7 BSMP 34,000 34,000 1,970 – 88,500 

Total StTr 

2 Liberty 6.70 3.74 2.96 – 10.45 

10 Northstar 1.09 2.28 0 – 7.48 

2 West Dock 0 --- 0 

2 Boulder Patch 10.5 6.66 3.39 – 16.7 

7 BSMP 13.42 16.45 0 – 52.6 

Calanoid copepods bioaccumulate phytol, a monounsaturated diterpenyl alcohol that is esterified 

with chlorophyll, in their phytoplankton food and convert it to pristane; the pristane accumulates 

to high concentrations in lipid droplets in the copepods (Avigan and Blumer, 1968). Pristane is 

readily bioaccumulated by the many species of marine invertebrates, fish, birds, and mammals 

that rely on copepods or their predators for food (Short, 2005). Short (2005) showed that mussels 

in Prince William Sound, AK, bioaccumulate pristane from fecal material produced by juvenile 

pink salmon that feed primarily on Neocalanus and not from copepod feces or dissolved pristane 

in the ambient water. Neocalanus from Prince William Sound contain 4000 to 8000 g/g pristane 

(Short, 2005). Pristane does not accumulate in marine sediments, but apparently is biodegraded 

rapidly at the sediment/water interface (Prahl and Carpenter, 1984). The amphipods sampled in 

this study (Anonyx nugax) are carnivores/scavengers that consume any carrion that settles to the 

sea floor and have been observed preying directly on pelagic copepods near the ice edge in the 

Barents Sea (Werner et al., 2004). Highest pristane concentrations were in amphipods collected 

in the Boulder Patch, a highly productive and biodiverse area north of the Liberty Prospect 

(Table 3-40). Lowest concentrations were in amphipods from Harrison Bay, suggesting that the 

pristane in amphipods doesn’t come primarily from peat in river runoff. 
156 

Amphipods also may bioaccumulate pristane from ingestion of detritus that accumulates at the 

sediment/water interface. Pristane is present at low concentrations in peat, which is eroding into 

coastal waters from shoreline sediments and upland soils (Steinhauer and Boehm, 1992). Peat 

collected from four rivers emptying into the Beaufort Sea contained 22 to 84 ng/g pristane. The 

amphipods probably accumulate pristane from ingestion of copepods and detritus, derived from 

dead copepods and zooplanktivorous fish, and from eroded peat. Clams may be feeding on a 

different fraction of the benthos. The indigenous clams, Astarte and Cyrtodaria, occupy sandy 

nearshore sediments and finer shallow bay and river mouth sediments, respectively, and may be 

feeding on organic particles in interstitial water and at the water/sediment interface (Bernard, 

1979). 

StTr. Concentrations of St/Tr, often used as tracers of crude oil sources, were low in all benthic 

invertebrates analyzed; amphipods, clams, and deployed mussels. The small amounts present 

may be from terrestrial plant materials, detritus, peat, or petroleum. The StTr profiles in the 

invertebrate tissues had some resemblance to the StTr profiles in Colville River peat, but little 

resemblance to the StTr in Northstar crude oil. Both recent and fossil biomarkers were present in 

the tissues, indicating that they were bioaccumulating hydrocarbons from organic detritus, peat, 

and possibly petroleum. Amphipods, mysids and clams also contained high concentrations of the 

biogenic PAH, perylene, which is abundant in Coleville River peat (Figure 3-23). The tissue 

residue data for PAH, SHC, and StTr indicate that hydrocarbons in tissues of nearshore benthic 

animals from the development area are derived in part from organic matter entering the Beaufort 

Sea from nearby rivers and also from coastal erosion. Contributions from the Northstar 

Development are negligible. 

Hydrocarbons in Amphipods and Clams from ANIMIDA (2000 and 2002). PAH, SHC, and 

StTr were measured in soft tissues of amphipods (Anonyx nugax) and clams (Astarte montagui 

and Cyrtodaria kurriana) in 2000 and 2002 as part of Task 2 of ANIMIDA (Brown et al., 2004). 

Sampling locations were similar to those used in this investigation and were primarily near the 

Northstar Development, the Liberty Prospect, and at a few locations in the BSMP. The results of 

these analyses are compared to those for 2004, 2005, and 2006 in Table 3-41. 

Mean concentrations of TPAH were similar in all years except 2005 in tissues of amphipods and 

clams from the Beaufort Sea development area (Table 3-41). TPAH concentrations in both taxa 

were lower in 2005 than in other years. The mean TPAH concentration in amphipods declined 

each year between 2000 and 2006; this trend was not observed in clams. Clams (Cyrtodaria 

kurriana) collected off the Kuparuk River in Gwydyr Bay (station 5F) in 2000 and 2002 

contained higher TPAH concentrations (195 and 175 ng/g dry wt) than the Astarte montagui

collected in 2000 and 2002 further offshore. 

Mean concentrations of TSHC were high and extremely variable, both within a year and from 

one year to another, in tissues of both amphipods and clams (Table 3-41). Highest TSHC 

concentrations in both taxa were in animals collected in 2004 and lowest concentrations were in 

animals collected in 2005. In any year, TSHC concentrations were higher in amphipod tissues 

than in clam tissues. Most of this difference was due to much higher pristane concentrations in 

amphipods than in clams. 
157 

Mean StTr biomarker concentrations were roughly similar in all years except 2005 in amphipods 

(Table 3-41). Mean biomarker concentrations tended to decline with time in clam tissues and 

were not detected in 2006. 

Table 3-41. Mean, SD, and range of concentrations of TPAH, TSHC, and StTr in soft tissues of 

amphipods (Anonyx nugax) and clams (Astarte montagui and Cyrtodaria kurriana) 

collected from the Beaufort Sea in 2000 and 2002 (ANIMIDA Task 2) and 2004, 2005, 

and 2006 (cANIMIDA Task 5). Concentrations are ng/g dry wt (data for 2000 and 2002 

were converted from wet wt. by multiplying by 5, based on ~89% moisture). From Brown 

et al. (2005) and Neff et al. (2009). 

Hydrocarbon Year Amphipods Clams 

Mean ±SD Range Mean (SD) Range 

TPAH 

2000 85.8 ± 18.4 60.0 – 115 90.4 ± 54.4 37.0 - 195 

2002 95.6 ± 41.6 55.0 – 175 80.6 ± 47.8 48.0 - 175 

2004 68.2 ± 33.8 39.6 – 143 95.8 ± 52.6 42.7 - 168 

2005 25.4 ± 13.5 8.25 – 50.0 38.4 ± 15.1 21.8 – 51.2 

2006 59.6 ± 29.8 19.7 – 123 141 ± 40.9 100 - 182 

TSHC 

2000 55,800 ± 45,300 0 – 130,000 6000 ± 8580 0 – 22,000 

2002 113,000 ± 71,800 23,500 – 260,000 14,100 ± 1390 12,500 – 16,000 

2004 444000 ± 8540 29800 - 54100 26,800 ± 14,400 678 – 39,700 

2005 31,600 ± 18,400 5171 – 67,100 1510 ± 517 1030 - 2230 

2006 63,000 ± 57,100 13,700 – 249,000 12,600 ± 2410 10,200 – 15,000 

StTr 

2000 18.8 ± 10.2 10.0 – 40.5 14.8 ± 3.67 10 - 20 

2002 10.8 ± 2.46 7.5 – 16.0 8.40 ± 3.97 5.00 – 15.5 

2004 12.2 ± 3.45 8.36 – 17.8 8.54 ± 5.37 2.92 – 17.1 

2005 6.22 ±1.89 4.53 – 8.02 1.72 ± 2.43 0 – 5.16 

2006 29.0 ± 11.8 20.7 – 55.0 0 0 

3.3.2.4 126BHydrocarbons in Deployed Mussels and SPMDs 

Deployed Mussels. Mussels (Mytilus trossulus) collected each year from a mussel mariculture 

operation, certified by the state for mussel harvesting, in Port Chatham at the mouth of Lower 

Cook Inlet, were deployed for approximately two weeks at Northstar, Liberty, and BSMP, to 

monitor bioavailability of PAH, SHC, and StTr in the water column. Unfortunately, reference 

mussels (collected at Port Chatham with mussels destined for deployment, but frozen for analysis 

immediately or after shipment to the North Slope), contained PAH, SHC, and StTr at 

concentrations similar to those in mussels following deployment in the Beaufort Sea 

(Table 3-42). In each year, the mean TPAH concentration in reference mussels was higher than 

that in mussels that were deployed for about two weeks at the three Beaufort Sea locations. Mean 

concentrations of TSHC and pristane were higher than or about the same as in deployed mussels. 

StTr concentrations were low in both reference and deployed mussels. 
158 

Table 3-42. Mean Concentrations of total polycyclic aromatic hydrocarbons (TPAH), total 

saturated hydrocarbons (TSHC), pristane, and steranes/triterpanes (StTr) in tissues of 

reference and deployed mussels and of TPAH in blank and deployed SPMDs used to 

monitor bioavailability of hydrocarbon concentrations in the water column of the Alaskan 

Beaufort Sea in 2004 through 2006. From Neff et al. (2009). 

Matrix Analytes Location 

Mean (SD) TPAH Concentration 

(ng/g dry wt or ng/SPMD) 

2004 2005 2006 

Deployed 

Mussels 

TPAH 

Reference 227 ± 34.9 32.8 ± 27.0 164 ± 36.2

Northstar 148 ± 45.8 13.0 91.6 ± 5.18 

Liberty 92.8 24.8 ± 14.7 134 ± 6.74 

BSMP 157 ± 46.8 31.5 ± 1.46 52.7 

TSHC 

Reference 6051  522 3632  151 23,159  2294 

Northstar 7624  2494 3381 21,024  3599 

Liberty 5725 2689  384 16,040  3145 

BSMP 6246  123 3137  380 16,033 

Pristane 

Reference 637  63.4 270  10.9 627  86.0 

Northstar 365  79.5 273 671  180 

Liberty 337 146  29.1 1153  214 

BSMP 413  162 290  106 850 

StTr 

Reference 12.2  3.79 5.87  5.87 ND 

Northstar 27.2  16.2 6.9 ND 

Liberty 13.5 ND ND 

BSMP 14.1  6.43 ND ND 

SPMDs TPAH 

Blank 699  55.0 No data No data 

Northstar 750 ± 182 No data No data 

Liberty 945 No data No data 

BSMP 606 ± 155 No data No data 

ND, not detected. 

Concentrations of individual PAH in the PAH assemblage in the deployed mussels were 

different than that in the reference mussels, indicating that some exchange of PAH between 

Beaufort Sea water and suspended particles and the mussel tissues had occurred during the 

deployment. 

The limited net bioaccumulation of PAH, SHC, and StTr by deployed mussels could have been 

due to a too short deployment period to allow for equilibration between Beaufort Sea water and 

mussel tissues or to stressful environmental conditions for Cook Inlet mussels in the Beaufort 

Sea. A deployment period of at least one month usually is recommended to allow tissue 

concentrations of non-polar organic chemicals, such as PAH, to equilibrate with concentrations 

in the ambient water and mussel food, particularly in cold water (Salazar and Salazar, 1995; 
159 

Durell et al., 2006). The deployment period for mussels in the Beaufort Sea in 2004, 2005, and 

2006 was limited to approximately two weeks because of logistic constraints. This may have 

been insufficient time for equilibration of some PAH, particularly 3- through 6-ring PAH that 

equilibrate slowly because of their low aqueous solubilities (Neff, 2002a). However, mussels 

were deployed near Northstar and at a reference site for three weeks in 2002 as part of the 

ANIMIDA Project. TPAH concentrations in the mussels from the longer 2002 deployment were 

similar to those in mussels deployed for 2 weeks in 2004, 2005, and 2006. Thus, a short 

deployment period doesn’t completely explain the lack of bioaccumulation of PAH by the 

deployed mussels. 

The short deployment period probably combined with unsatisfactory environmental conditions to 

limit PAH equilibration between mussel tissues and Beaufort Sea water. Ambient water 

temperature and salinity in July and August within a few meters of the bottom at the locations 

where mussels were deployed usually was in the range of -1.5oC to +2oC and 20‰ to 32‰, 

respectively. Mytilus trossulus is the most cold-tolerant of the mytilid bivalves; they can tolerate 

temperatures at least as low as -2oC (Cusson et al., 2005). However, clearance rate, food 

absorption efficiency, and metabolic rate, measured as the scope for growth, decreases to low 

levels in M. trossulus at a temperature of - 1 ̊C; mussels transferred from + 4 or + 8 ̊C to - 1 ̊C 

decreased respiration and required more than 5 days to recover (Cusson et al., 2005). Feeding 

also is depressed markedly by high suspended sediment concentrations and low phytoplankton 

concentrations (Thompson, 1984). The salinity of the near-bottom water of the Beaufort Sea is in 

the optimum range for M. trossulus and similar to what it is at Port Chatham. Thus, since the 

Port Chatham mussels were not acclimated for more than a few days to Beaufort Sea conditions 

before deployment, low ambient temperature and high suspended sediment loads, probably 

coupled with a short deployment time may have limited PAH bioaccumulation (and depuration) 

in the deployed mussels. However, mussels from Port Chatham that were deployed near 

Northstar and at a reference area in 2002 as part of the ANIMIDA Project exhibited byssal thread 

growth, an indication that they were active during deployment. Activity probably was slowed 

enough to slow equilibration of hydrocarbons between Beaufort Sea water and food and tissues 

of deployed mussels. Future deployments should be for longer periods of time (preferably one 

month or more) with mussels that have been acclimated to low Beaufort Sea water temperatures 

for a few weeks. 

SPMDs. SPMDs were deployed at three locations in the Beaufort Sea in 2004 to measure PAH 

in the water column. They produced little useful data because blank (unused) SPMDs contained 

about as much TPAH as deployed ones (Table 3-42). As with the deployed mussels, there was 

some evidence of exchange of some PAH between the ambient Beaufort Sea water and the 

SPMDs. PAH exchange probably was slowed by the low ambient temperatures and short 

deployment period. As with mussels, SPMDs and other passive samplers require deployment 

times of a month or more to reach equilibrium with dissolved PAH, particularly the higher 

molecular weight PAH, in the water column (Cornelissen et al., 2008). The dominant PAH in 

both blank and deployed SPMDs were naphthalenes; very little high molecular weight PAH were 

present, indicating limited equilibration and low concentrations of high molecular weight PAH in 

Beaufort Sea water. Therefore, SPMDs showed no advantage over mussels and they were not 

used in subsequent years. 
160 

SPMDs were deployed in 2002 at locations near the Northstar Development and at a reference 

site to the east as part of the ANIMIDA Project. Blank SPMDs from 2002 contained more than 

twice the amount of PAH contained in blank SPMDs from 2004 (1604 ng/SPMD versus 699 

ng/SPMD). As in 2004, naphthalenes were the dominant PAH in both blanks and deployed 

SPMDs in 2002. Concentrations of most PAH in the SPMDs deployed in 2002 were higher than 

the concentrations of the corresponding PAH in SPMDs deployed in 2004, confirming that the 

blank PAH were masking any PAH analytes accumulated during deployment. 

The combined SPMD and deployed mussel PAH data indicate that PAH concentrations were 

very low (probably lower than at Port Chatham) in Beaufort Sea water and suspended fine 

particulate matter. Amounts of PAH in SPMDs following deployment in the Beaufort Sea were 

lower than amounts in most SPMDs that had been deployed in the vicinity of offshore 

production platforms in the North Sea (Durell et al., 2006). Estimated TPAH concentrations in 

North Sea water, estimated from amounts of individual PAH in SPMDs that had been deployed 

for a month in the North Sea, range from about 4 to 25 ng/L at locations where the SPMDS 

contained amounts of TPAH similar to those in the SPMDs deployed in the Beaufort Sea. The 

background concentration of TPAH in coastal estuarine and marine waters is about 5 to 10 ng/L 

(Neff, 2002a). Beaufort Sea water probably contained similar or lower TPAH concentrations. 

Summary. As discussed above, the PAH, SHC, and StTr profiles in animal tissues and SPMDs 

from the Beaufort Sea are consistent with a primarily petrogenic source. Thus, marine biota from 

throughout the production area of the Beaufort Sea are being exposed to low concentrations of 

fossil hydrocarbons. These PAH, SHC, and StTr may be coming from aerial deposition (arctic 

haze and combustion plumes offshore and onshore oil and gas operations), small boat fuel leaks, 

small releases from production activities on and offshore, and runoff from land, mainly via rivers 

(Steinhauer and Boehm, 1992), particularly from erosion of peat from river banks and the shore. 

TPAH concentrations were not higher in marine animals collected near the Northstar 

Development than at other areas of the Beaufort Sea, indicating that the offshore operations were 

not a significant source of PAH in the animal tissues. The TPAH concentrations in tissues of 

Beaufort Sea invertebrates and fish are well below concentrations that might pose a health risk to 

fish, wildlife, and humans that might consume marine foods from the Beaufort Sea (Neff et al., 

2006). 

3.4 15BConceptual Model of Bioaccumulation and Trophic Transfer of Chemicals in 

the Beaufort Sea Food Web 

A conceptual food web model is useful as a tool for designing scientifically defensible studies of 

the sources and distribution of chemical contaminants in biological communities in the coastal 

Alaskan Beaufort Sea. It provides the basis for development of testable null hypotheses about 

relationships among physical and chemical disturbance of marine ecosystems by offshore oil 

development and production operations, climate change, and ecological changes. 

3.4.1 61BContaminant Sources in the Beaufort Sea 

Metals and hydrocarbons (SHC, PAH, St/Tr) are natural ingredients of the Alaskan Beaufort Sea 

environment. Large amounts of metals and hydrocarbons enter the Beaufort Sea each year 

associated with suspended particles in river runoff (See Section 3.1.1 above) (Yunker et al., 

1991, 1996; Yunker and MacDonald, 1995; Steinhauer and Boehm, 1992; Trefry et al., 2003, 
161 

2004a,b, 2009; Rember and Trefry, 2004). Additional metals and hydrocarbons enter coastal 

waters and sediments of the Beaufort Sea from dry and wet deposition from the atmosphere. The 

arctic aerosol over northern Canada and Alaska contains relatively high concentrations of metals, 

PAH, SHC, and other persistent organic pollutants (POPs) (Matsumoto et al., 1998; Muir et al., 

1999; Cheng and Schroeder, 2000). Climate change in the Arctic results in changing wind 

patterns that in turn alter the patterns and masses of contaminants deposited to the Arctic seas 

from aerosols (MacDonald, et al., 2005). 

Metals and petroleum hydrocarbons also may enter coastal and offshore waters of the Beaufort 

Sea from coastal and offshore oil and gas operations (Steinhauer and Boehm, 1992; Trefry et al., 

2003). The major sources of metals in Beaufort Sea sediments from oil development activities 

are causeway and drilling island construction and drilling mud and cuttings discharges (Northern 

Technical Services, 1982; Naidu et al., 2001; Neff, 2002b, 2010). Island construction material 

usually has a metal concentration similar to that of natural soils and sediments, but sometimes 

may contain elevated concentrations of some metals (e.g., Crippen et al., 1980). 

The metals frequently found in drilling muds and cuttings that are of greatest concern because of 

their potential toxicity and/or abundance in drilling muds include arsenic, barium, chromium, 

cadmium, copper, iron, lead, mercury, nickel, and zinc. Only barium, chromium, iron, lead, and 

zinc, sometimes are present in drilling mud/cuttings solids at concentrations significantly higher 

(> 100-fold) than concentrations in clean marine sediments (Neff, 2005, 2010). However, most 

of these metals are present as insoluble sulfide inclusions in drilling barite and are not 

bioavailable to marine animals (Neff, 2008). 

PAH also have natural and anthropogenic sources (Neff, 2002a). The major sources of the 

complex PAH assemblages found in most North Slope and Beaufort Sea soils and sediments are 

combustion soot and fossil hydrocarbon mixtures (peat, coal, and petroleum). There are vast 

peatlands, covering an area larger than the area of the state of California, on the Alaskan North 

Slope (Jones and Yu, 2010). Most of this peat is more than 8900 years old. These peat deposits 

gradually erode or decompose to POC and DOC, and are carried to the Beaufort Sea in river 

flows and coastal erosion. The rate of loss of tundra peat is expected to increase with global 

warming. PAH from these sources enter the Beaufort Sea in natural seeps, petroleum spills, river 

runoff, coastal erosion, and aerial deposition. 

Oil development and production activities on the North Slope also contribute PAH to coastal 

waters of the Beaufort Sea. In the past, the major sources of PAH inputs to the environment from 

oil and gas activities were permitted discharges of drilling mud/cuttings and produced water 

(Neff, 2002a, 2005, 2010). However, produced water is not discharged to coastal waters of the 

Alaskan Beaufort Sea; it is reinjected. Currently, water based drilling muds are the only ones 

used and discharged offshore in the Beaufort Sea. The current NPDES permit for Alaska allows 

discharge of water based drilling muds and cuttings to Federal waters of the Beaufort Sea if they 

meet effluent limitation guidelines. Drilling mud discharges usually are limited to winter 

discharges onto the ice in deep water. The most recent drilling mud and cuttings discharges to 

State/Federal lease tracts in the Beaufort Sea probably were from the McCovey exploratory well, 

drilled in 2002 northeast of the Northstar production facility. An estimated total of 939 m3

 of 

water based drilling muds and cuttings were discharged from McCovey to the ice (Table 1-3). 

Drilling muds and cuttings were not discharged during development drilling at Northstar. 
162 

Water based drilling muds, if used and discharged in accordance with regulations; contribute 

only small amounts of hydrocarbons to the local marine environment. Completion fluids that 

usually are used to drill the hydrocarbon-bearing formation are not permitted for discharge 

because they often contain free oil. They may be reinjected if a suitable geologic formation is 

available or transported to shore for upland disposal. 

PAH also are emitted to the atmosphere by flaring waste gases at production platforms or gastreatment facilities. A total of 162,321 million standard cubic feet (mscf) of waste gas was flared 

at Northstar in 2004, almost sevenfold lower than peak flaring of more than 1,100,000 mscf in 

2002. (Alaska Oil and Gas Conservation Commission, 2005). The PAH concentration in the flare 

exhaust is not known. Hydrocarbons, including PAH, may also be emitted in diesel exhaust and 

fugitive emissions from oil industry support vessels. Accidental drilling mud/cuttings, petroleum, 

and wastewater releases also are a potential source of PAH to the Beaufort Sea. 

3.4.2 62BBioaccumulation and Trophic Transfer of Metals and Hydrocarbons in the 

Beaufort Sea Food Web 

There is concern that offshore oil and gas development may harm the Beaufort Sea marine 

environment by habitat alteration and by contamination of the local food web with harmful 

chemicals from accidental or intentional discharges from development and production activities. 

Marine invertebrates, fish, birds, and mammals living in the Beaufort Sea are able to 

bioaccumulate metals and PAH from the ambient seawater, from contaminated sediments, and 

from their food (Neff, 2002a). The concentrations of metals and PAH in tissues of marine 

animals are assumed to be at equilibrium with concentrations in the ambient water and food. 

Benthic invertebrates bioaccumulate contaminants primarily from solution in sediment pore 

water, overlying bottom water, and ingestion of sediment particles; benthic carnivores may also 

bioaccumulate contaminants from their food. Demersal and pelagic invertebrates, fish, birds, and 

mammals bioaccumulate the contaminants primarily from their food. Thus, a local increase in 

concentrations of metals and PAH in water or sediments due to oil development and production 

discharges may lead to an increase in the concentration of the contaminants in tissues of marine 

organisms in the local food web. As discussed above, the ANIMIDA/cANIMIDA Project has 

monitored intensively between 1999 and 2006 and has found no evidence of ecologically 

significant increases of concentrations of metals and hydrocarbons in Beaufort Sea sediments 

and tissues of marine animals. 

None of the target PAH or metals is known to biomagnify in marine food webs (with the 

possible exception of arsenic and methylmercury) (Neff, 2002a,b; Dehn et al., 2006a,b). Some 

metals, such as cadmium, bioaccumulate continuously in certain tissues, such as kidneys, during 

the life of marine animals (Dehn et al., 2006a,b). The accumulated metals usually are in solid, 

non-bioavailable concretions, such as mercuric selenide in cetacean liver and solid cadmium 

concretions in walrus liver; this is not considered biomagnification (Neff, 2002a,b). This means 

that the concentrations of bioavailable metals and hydrocarbons do not increase “up the food 

chain” with highest concentrations in the top consumer, usually a marine bird or mammal. 

However, all the target contaminants are transferred through marine food webs; measured 

concentrations are lower in the whole predator tissues than in the whole prey tissues. 

Arctic marine animals are about as sensitive as or slightly more sensitive than temperate and 

tropical species to petroleum and metals toxicity (Neff, 2002a; Perkins et al., 2003; Chapman 
163 

and Riddle, 2005). Thus, if chemicals from offshore oil development activities are 

bioaccumulated to high enough concentrations, they may cause adverse effects in the Beaufort 

Sea food web. 

This conceptual model of bioaccumulation, trophic transfer, and effects was used as a basis for 

developing the objectives and study design for Task 5 of cANIMIDA. A major focus of this task 

is to develop the information needed to protect indigenous people and the subsistence resources 

upon which they rely from injury due to chemical contamination from offshore oil and gas 

operations. This conceptual model is being used to evaluate the possible bioaccumulation and 

food web transfer of metals and PAH derived from offshore oil and gas development activities in 

the Beaufort Sea. Sediments, benthic invertebrates (lower trophic level), and fish (higher trophic 

level) from the Beaufort Sea development area have been analyzed in the ANIMIDA and 

cANIMIDA Projects for several metals and PAH that are associated with oil development 

activities (See Section 3.3 above). Marine mammals and birds (the apex consumers: Figure 3-56) 

from the Beaufort Sea and other Arctic marine environments have not been analyzed for PAH. 

However, there is a large amount of data available on concentrations of several metals and 

organochlorine compounds in several species of marine birds and mammals from the Beaufort 

Sea (e.g., Honda et al., 1990; Zeisler et al., 1993; Mackey et al., 1995, 1996; Krone et al., 1999; 

Woshner et al., 2001, 2002; Hoekstra et al., 2002, 2003, 2005; Kucklick et al., 2002; Borga et al., 

2004; Franson et al., 2004; Dehn et al., 2005, 2006a,b; Riget et al., 2005; O’hara et al., 1999, 

2006). However, there are no published data on the concentrations of PAH in tissues of Arctic 

marine mammals from Arctic offshore oil development areas (i.e., Arctic Alaska, Canada, 

Greenland, the Norwegian and Russian Barents Sea, and the Russian Far East). 

3.4.3 63BThe Beaufort Sea Food Web 

The harsh marine environment of the Beaufort Sea, with wide seasonal variations in light 

intensity, ice cover, freshwater input from rivers, and nutrient concentrations results in wide 

seasonal cycles of primary production, and complex, seasonally variable food webs (Walsh et al., 

2005). Food web structure and carbon flow on the inner continental shelf of the Alaskan 

Beaufort Sea are different in the nearshore (inside the barrier islands) and offshore environments 

and are weakly linked (Figure 3-56). For example, although terrestrially derived peat makes a 

substantial contribution to available particulate organic carbon (POC) in the nearshore marine 

environment (lower left side of Figure 3-56), it contributes much less to offshore organic carbon 

fluxes (right side of Figure 3-56) (Schell, 1983; Dunton et al., 2006). For example, arctic cod in 

Beaufort Sea lagoons may derive up to 70 percent of their carbon from terrestrial carbon (mostly 

peat); offshore populations derive most of their carbon from zooplankton (Dunton et al., 2006). 

The Beaufort Sea food web is a relatively simple one with relatively few abundant taxa at each 

trophic level (Figures 3-56 and 3-57). Nutrients to support primary production in the Alaskan 

Beaufort Sea are derived primarily from inflows from the Bering Sea, Anadyr Water (from the 

Russian Chukchi Sea), the Canadian Beaufort Sea, and upwelling from the Arctic Basin (Dunton 

et al., 2003, 2004). Primary production is pelagic (phytoplankton), epontic (living on the 

underside of sea ice), and benthic (micro- and macro-algae living on the sea floor: e.g., the 

Boulder Patch - See section 3.5 below). The epontic community along the seasonal ice edge may 

contribute substantially to overall pelagic production. Epontic microalgae support diverse 

communities of ice-associated meiofauna that help support spring zooplankton blooms (Carey 

and Montagna, 1982). 
164 

Figure 3-56. A generalized food web structure showing the sources of organic carbon, including 

peat, in the Alaskan Beaufort Sea coastal ecosystems. The shading of the rectangles 

below each taxon shows the relative contribution and pathway of carbon from 

freshwater algae, terrestrial peat, and marine algae in the food web. Food chain 

structure grades from near-shore, freshwater/estuarine on the left to offshore marine 

on the right. Modified from Schell et al. (1982). 

Primary production, measured as chlorophyll a concentrations in surface waters, is lower in the 

Beaufort than in the Chukchi Sea (Dunton et al., 2003, 2004). Near-shore areas east of Barrow 

and off the Coleville River and Mackenzie River have the highest primary production in coastal 

and continental shelf waters of the Beaufort Sea. This probably is caused mainly by the large 

flux of organic carbon into the Canadian and Alaskan Beaufort Sea from rivers (Yunker et al., 

2005; Elmquist et al., 2008; Holmes et al., 2008; Trefry et al., 2009; Magen et al., 2010). These 

regions of high productivity are import to fall-migrating bowhead whales. 

Particulate organic carbon (POC), produced by primary producers (phytoplankton) or in runoff 

from land, may be consumed by primary consumers (mostly zooplankton), or exported to 

sediments or off the shelf (Wasserman et al., 2003; Moran et al., 2005). The POC supports 

blooms of zooplankton communities, dominated by calanoid copepods and euphausiids, which 

are consumed by bowhead whales. 
165 

In the nutrient rich northeastern Chukchi Sea, the fraction of primary production that is exported 

from the water column increases from about 15 percent in the spring to about 32 percent in the 

summer (Moran et al., 2005). POC flux to the benthos probably is lower in the nutrient-depleted 

Beaufort Sea (Dunton et al., 2003, 2004, 2006). Because of the lower POC flux, benthic biomass 

in the Beaufort Sea (average 33 g/m2) is much lower than that in the Chukchi Sea (167 g/m2) 

(Dunton et al., 2003, 2004). POC in sediments supports development of a rich benthic fauna that 

supports benthic feeders, such as some seals and many species of demersal fish, and results in 

strong benthic/pelagic coupling of nutrients (Figure 3-56). Sediments in the Beaufort Sea contain 

organic matter from both marine and terrigenous sources (Yunker et al., 2005; Trefry et al., 

2009; Magan et al., 2010). This organic matter tends to sequester metals and hydrocarbons and is 

ingested by benthic fauna, facilitating bioaccumulation and trophic transfer of contaminants in 

the Beaufort Sea food web. 

Global warming may dramatically change ecosystem dynamics, including the distribution of 

marine organisms and chemical contaminants in the Chukchi Sea. Environmental changes may 

include: 1) increased pelagic primary and secondary production during extended open-water 

conditions in the summer (based on surplus nutrients, currently underutilized); 2) reduced 

benthic and pelagic biomass in coastal/shelf areas (due to increased river runoff and resulting 

changes in salinity and turbidity; and 3) increased pelagic grazing and recycling in open-water 

conditions at the expense of the current benthic/pelagic coupling in part of the ice-covered shelf 

regions (due to increased pelagic consumption versus vertical flux) (Bluhm and Gradinger, 

2008). These changes may benefit pelagic feeders, such as bowhead whales and some pinnipeds 

and marine birds, and harm benthic feeders such benthic-feeding pinnipeds and fish. It will also 

affect the trophic transfer and cycling of chemical contaminants in the Chukchi Sea food web. 

Grainger (1965) identified two zooplankton communities in waters less than 100 m deep in the 

Alaskan Beaufort Sea. The community occupying Arctic surface water is dominated by 

coelenterates, ctenophores, and copepods. Dominant copepods include Calanus hyperboreus, 

Calanus glacialis, Pseudocalanus minutus, Metridia longa, and Oithoma similes. The second 

zooplankton community is associated in summer with warmer, less saline nearshore waters, 

primarily inside the barrier islands. Dominant copepods include Limnocalanus macrouris, 

Acartia clausi, Eurytemora herdmani, and Derjugina tolli. Calanoid copepods, primarily 

Pseudocalanus, are abundant under the sea ice during winter and early spring; they are replaced 

in early summer by cyclopoid and harpacticoid copepods, hydrozoans, amphipods, larvaceans 

and larval stages of planktonic and benthic invertebrates (Horner and Murphy, 1985). Griffiths 

and Thompson (2002) identified three zooplankton communities in waters out to 200 m off the 

eastern Alaskan Beaufort Sea (Camden Bay and eastward to the Canadian border). Copepods are 

dominant in all three communities, accounting for 50 to 75% of the total zooplankton biomass.

Three species represent more than 85% of the total copepod biomass: Calanus hyperboreus, C. 

glacialis, and Limnocalanus macrourus. Calanoid copepods are the main prey of bowhead 

whales in the central and eastern Beaufort Sea. 

Euphausiids (Thysanoessa inermis and T. raschii) are much less abundant than calanoid 

copepods in the eastern Beaufort Sea. However, they are seasonally abundant in the Chukchi Sea 

and western Beaufort Sea. Euphausiids are transported by deep-water currents from the Bering 

Sea, through the Chukchi Sea to waters off Barrow, and then into the western Beaufort Sea 
166 

(Berline et al., 2008). They are the main prey of bowhead whales that aggregate to feed off 

Barrow and in the Chukchi Sea during the fall migration. 

The abundance and distribution of zooplankton is extremely variable in different seasons and 

years. Total zooplankton wet biomass in waters of the eastern Alaskan Beaufort Sea ranges from 

170 to more than 383 mg/m3

 in different years; biomass is greater at depths of more than 10 m 

than at the surface (Griffiths and Thomson (2002). Wet biomass of zooplankton can be as high as 

3,500 mg/m3 in dense patches. The feeding threshold for bowhead whales may be as high as 800 

mg zooplankton wet biomass/m3 of seawater (Griffiths et al., 2002; MMS, 2006), highlighting 

the importance of dense zooplankton patches to bowhead whales. 

These primary consumers are preyed on by a variety of secondary consumers (carnivores), 

including several species of anadromous and marine fish, marine birds, and marine mammals, 

including some ice seals (e.g., ringed, ribbon, and bearded seals) and baleen whales (bowhead 

whales) (Figure 3-57). Other marine fish, birds, and mammals consume primarily fish or other 

marine mammals (beluga whales, polar bears). Crustaceans, such as copepods, euphausiids, 

amphipods, isopods, and mysids, are abundant in coastal, estuarine waters where they are preyed 

upon heavily by several species of fish (Table 3-43). Many of the coastal fish in the Beaufort Sea 

feed primarily on small fish, particularly arctic cod (Frost and Lowry, 1984). 

Table 3-43. Anadromous and marine fish collected for Task 5 of the cANIMIDA program from 

coastal waters of the Beaufort Sea and their food preferences. Data from Thorsteinson and 

Wilson (2006) and Craig et al. (1984). 

Common Name Scientific Name Food Preferences 

Marine Fish 

Arctic cod Boreogadus saida Mysids, amphipods, copepods 

Four horn sculpin Myxocephalus quadricornis Amphipods, isopods, polychaetes 

Arctic flounder Liopseta glacialis Demersal & benthic crustacea, 

polychaetes 

Anadromous Fish 

Arctic char Salvelinus alpinus Mysids, small fish 

Arctic cisco Coregonus autumnalis Mysids, larval & juvenile fish 

Least cisco C. sardinella Mysids, amphipods 

Broad whitefish C. nasus Chironomids, amphipods 

Humpback broad whitefish C. pidschian Chironomids, amphipods 

Arctic cod (Boreogadus saida) is considered a key species in the Beaufort Sea marine ecosystem 

(Lowry and Frost, 1981; Bradstreet et al., 1986). They are a major link between lower trophic 

level benthic and pelagic primary consumers and upper trophic level apex consumers, such as 

several species of marine birds, seals, and mammals (Figures 3-56 and 3-57; Tables 3-44, 3-45, 

and 3-46). They consume primarily gammarid amphipods, copepods, and mysids, and are 

consumed by many birds and mammals, including black kittiwakes, arctic terns, thick-billed 

murres, black guillemots, and glaucous gulls. 
167 

Figure 3-57. The importance of zooplankton and arctic cod in the Arctic pelagic food web 

leading to mammalian consumers, including man. Based on Macdonald et al. (2005). 

Bowhead whales and some marine birds and seals also rely on marine crustaceans, particularly 

copepods and euphausiids, for food. (Tables 3-44, 3-45, and 3-46). The amphipods, mysids, and 

isopods that are such important foods for many fish, birds and mammals, consume primarily 

smaller benthic crustaceans and polychaetes, diatoms, and peat (Craig et al., 1984). 

Bowhead whales feed on pelagic euphausiids, copepods, mysids, hyperiid amphipods, and 

occasionally small fish (Lowry and Frost, 1984; Richardson et al., 1995; Lowry et al., 2004). 

Bowhead whales feed throughout the Alaskan Beaufort Sea during both the spring (eastward) 

and fall (westward) migrations between the Bering/Chukchi Seas and the Canadian Beaufort Sea. 

They feed less during the spring than the fall migration (Lowry et al., 2004). Carroll et al. (1987) 

reported large numbers of bowheads feeding near Point Barrow during the 1985 spring 

migration. The dominant prey in the whale stomachs were calanoid copepods and euphausiids. 

They also feed extensively during their fall, nearshore migration through the Alaskan Beaufort 

Sea to northeastern Chukchi Sea (Lowry et al., 2004). (Landino et al., 1994) reported a large 
168 

aggregation of bowhead whales feeding near Point Barrow in late October 1992. Calanoid 

copepods were the dominant prey in bowhead whales collected off Kaktovik (eastern Beaufort 

Sea) and euphausiids were the dominant prey in whales collected off Point Barrow (western 

Beaufort Sea) (Table 3-44). 

Table 3-44. Diet composition (% of stomach contents) in arctic cod, bowhead whales, beluga 

whales, and ringed seals in the Alaskan Beaufort Sea. From Frost and Lowry (1984) and 

Lowry and Sheffield (2002). 

Prey Arctic 

Cod 

Bowhead Whales Beluga 

Whale 

Ringed Seal 

E. Beaufort W. Beaufort Nov-Mar Apr-Jun Aug-Sep 

Isopod 16 

Hyperiid 

Amphipod 

1 0 – 17 44 

Gammarid 

Amphipod 

12 32 

Copepod 50 60 8 

Euphausiid 3 37 92 20 21 

Mysid 20 1 19 

Arctic Cod 5 80 75 - 90 6 30 

Other Fish 1 10 

Misc. 9 1 10 7 5 

Table 3-45 . Diet composition in black kittiwakes, red phalaropes, Sabine’s gulls, and arctic terns 

feeding in nearshore and offshore waters of the Alaskan Beaufort Sea. From Frost and 

Lowry (1984). 

Prey 

Black Kittiwake Red 

Phalarope Sabine’s Gull Arctic Tern 

Offshore Nearshore Offshore Offshore Nearshore Offshore Nearshore

Isopod 

Hyperiid 

Amphipod 

1 67 1 54 6 1 

Gammarid 

Amphipod 

 14 49 49 31 

Copepod 11 

Euphausiid 5 13 4 35 23 

Mysid 11 13 24 

Shrimp 1 3 

Mollusks 

Arctic Cod 95 5 13 4 64 20 

Other Fish 1 12 

Misc. 3 3 20 17 13 14 

 
169 

Table 3-46. Diet composition in long-tailed ducks, common and king eiders, thick billed murres, 

black guillemots, and glaucous gulls feeding in nearshore and offshore waters of the 

Alaskan Beaufort Sea. From Frost and Lowry (1984). 

Prey 

Long-tail 

Duck 

Comm. 

Eider King Eider Thick-bill Murre 

Black 

Guillemot Glaucous Gull 

Nearshore Nearshore Nearshore Offshore Offshore Offshore Nearshore

Isopod 83 89 12 

Hyperiid 

Amphipod 

 1 1 1 

Gammarid 

Amphipod 

23 1 2 

Copepod 

Euphausiid 17 13 

Mysid 20 15 

Shrimp 

Mollusks 22 1 2 

Arctic Cod 99 100 17 60 

Other Fish 

Misc. 75 

Lee and Schell (2002) compared carbon isotopes in zooplankton to those in bowhead whale 

muscle and estimated that 10 to 26% of annual bowhead feeding activity was in the eastern and 

central Beaufort Sea. Thomson et al. (2002) estimated that they may obtain approximately 2.4% 

of their annual energy requirements feeding in the Alaskan Beaufort Sea. Although bowheads 

feed extensively in the Alaskan Beaufort Sea, the times, extent, and locations of feeding vary 

widely from year to year. The variation is due in large part to variations in the temporal and 

spatial distribution of dense patches of zooplankton upon which the whales depend, which are 

controlled by ocean conditions, particularly inputs of primary nutrients in river runoff and 

upwelling from the continental shelf and ice edge (Asjian et al., 2009). 

Beluga whales (Delphinapterus leucas) migrate annually through the Alaskan Beaufort Sea, 

usually further offshore than bowhead whales, between summer feeding areas in the Canadian 

Beaufort Sea and wintering areas in the Bering Sea and feed heavily on pelagic and demersal fish 

(Treacy, 2002). The dominant prey of beluga whales, because of its abundance in offshore 

waters, is the arctic cod (Table 3-44). 

Some ice-associated seals, such as the bearded seal (Erignathus barbatus) and ribbon seal 

(Phoca faciata), which feed in coastal waters of the Beaufort Sea in some seasons, feed heavily 

on benthic invertebrates and demersal fish, such as shrimp, crabs, arctic cod, and sculpins 

(Wynne, 1997). Ringed seals (Phoca hispida), the principal food of polar bears, are common in 

all seasons in the Beaufort Sea. Their diet varies seasonally from primarily isopods, amphipods, 

euphausiids, and mysids in spring during retreat of the sea ice, to amphipods, euphausiids, and 

arctic cod during the summer open-water season, to primarily arctic cod during the winter when 

the seals occupy the sea ice (Table 3-44). 
170 

The protected spectacled eider (Somateria fischeri) and king eider (Somateria spectabilis) that 

breed along the arctic coastal plain from Barrow to the Canadian border, feed primarily on 

benthic isopods and mysids, as well as small numbers of mollusks that they gather in shallow 

coastal waters (<30 m) (Dau and Kistchinski, 1977; Frost and Lowry, 1984) (Table 3-46). 

Several species of marine birds in the Alaskan Beaufort Sea, including black kittiwakes, arctic 

terns, thick-billed murres, black guillemots, and glaucous gulls, feed heavily on arctic cod, 

which, in turn, feed mainly on mysids, copepods, and amphipods (Frost and Lowry, 1984) 

(Figure 3-57; Tables 3-44, 3-45, and 3-46). The copepods that are the principal foods of bowhead 

whales also are consumed by red phalaropes, Sabine’s gulls, arctic terns, long-tailed ducks, and 

glaucous gulls (Tables 3-45 and 3-46). 

Contaminants introduced into the marine environment from offshore oil and gas operations are 

likely to accumulate in this Beaufort Sea food web. Although none of the contaminants measured 

in tissues of Beaufort Sea animals in cANIMIDA Task 5 are known to biomagnify (with the 

exception of arsenic and methylmercury), they all can be spread through trophic transfer through 

the food web. The tissue residue data collected to date in Task 5 of the cANIMIDA Project has 

not identified any metal or PAH contaminants from offshore oil and gas operations that are 

present at elevated concentrations in selected representatives of the Beaufort Sea food web. 

Some of the petroleum PAH in the tissues of invertebrates and fish could have been derived from 

offshore operations; however, concentrations are very low, mostly in the range of natural 

background, indicating a lack of significant risk to the local ecosystem. 

An example of the distribution of total mercury in selected components of the Beaufort Sea food 

web is shown in Figure 3-30. The mercury data, collected from several sources, including 

cANIMIDA (Trefry et al., 2009; Semmler, 2006), show that there is a large increase in total 

mercury concentrations from the ambient water, to phytoplankton, to zooplankton (Table 3-17). 

The apparent biomagnification factor (BF= concentration in consumer/concentration in prey) for 

the transfer of total mercury and methylmercury from phytoplankton to zooplankton is 2.8 and 

7.1, respectively. Mercury concentration then decreases from zooplankton to arctic fish (BF = 

0.54). Highest concentrations of total mercury are in liver of the marine mammals in Table 3-18. 

The apparent BFs for total mercury concentration from whole soft tissues of prey to liver tissue 

of bowhead whales, beluga whales, and ringed seals are 3.6, 2000, and 586, respectively. Thus, 

apparent biomagnifications of mercury from zooplankton to bowhead whales is much less than 

biomagnification from arctic cod to beluga whales or ringed seals. Polar bears from the Beaufort 

Sea contain liver total mercury concentrations ranging from 7500 to 272,000 ng/g dry wt (Table 

3-18); the BF for total mercury from prey (ringed seal) liver to polar bear liver is 3 to 4. 

Because of their low trophic status, bowhead whales contain low concentrations of metals, 

including mercury in all tissues (Table 3-47). Mercury concentrations are highest in liver and 

kidney, as are concentrations of cadmium and selenium. The presence of mercury and selenium 

in liver and kidney indicates that the mercury in these organs probably is present as an insoluble, 

inert mercury-selenium complex. 
171 

Table 3-47. Range of concentrations of selected metals in tissues and organs of bowhead whales 

(Balaena mysticetus) collected by subsistence hunters near Barrow, Alaska. 

Concentrations are mg/kg wet wt (ppm: can be converted to approximate dry wt 

concentration by multiplying by five). From O’Hara et al. (2006). 

Organ/ Tissue Cd Cu Se Zn Hg 

Kidney 0.47-70.2 1.13-2.20 0.77-2.04 12.7-57.2 0.003-0.18 

Liver 0.28-42.2 3.08-8.96 0.50-1.79 23.6-65.1 0.01-0.19 

Muscle 0.007-0.212 0.36-0.76 0.13-0.25 24.7-62.8 0.003-0.04 

Heart 0.03-3.64 0.90-1.36 0.24-0.92 21.8-30.3 0.006-0.031 

Intestine 0.04-1.52 0.45-1.47 0.18-0.63 14.3-31.7 0.004-0.014 

Tongue 0.005-0.22 0.11-0.35 0.045-0.18 1.10-15.7 0.003-0.046 

Blubber 0.009-0.015 0.10-0.16 0.06-0.14 0.70-1.16 0.005-0.008 

Epidermis --- 0.22-0.72 0.39-0.86 9.88-18.7 0.004-0.037 

Biomagnification of total mercury in marine food chains usually is attributed to selective 

accumulation and retention of methylmercury. Mason et al. (1995, 1996) showed that the 

preferential bioaccumulation of methylmercury in pelagic marine food webs occurs primarily at 

the level of phytoplankton. Phytoplankton are able to bioaccumulate both inorganic mercury and 

methylmercury from water. The inorganic mercury binds to cell membranes of the plants in a 

relatively non-bioavailable form, whereas the methylmercury accumulates in the cytoplasm. 

Zooplankton that feed on phytoplankton assimilate more methylmercury than inorganic mercury 

(Table 3-17). Marine animals that feed on the zooplankton also assimilate more methylmercury 

than inorganic mercury; they also are able to eliminated inorganic mercury more rapidly than 

methylmercury from their tissues, facilitating the greater accumulation of methylmercury, 

particularly at higher trophic levels in marine food webs. 

Mercury concentrations in marine waters of much of the Arctic are higher than concentrations in 

temperate and tropical waters due in large part to deposition of metallic and inorganic mercury 

from long-range transport and deposition from the atmosphere (Skov et al., 2004). There is no 

evidence that significant amounts of mercury are coming from oil operations around Prudhoe 

Bay (Snyder-Conn et al., 1997). 

Less than 3.5% of the total mercury in Beaufort Sea coastal water is methylmercury (Trefry et 

al., 2009; Semmler, 2006). Methylmercury in the water column and in tissues of marine 

organisms is derived from microbial methylation of inorganic mercury in suboxic layers in the 

water column and sediments (Rolfhus and Fitzgerald, 1995; Gagnon et al., 1996). The 

methylmercury in Beaufort Sea coastal water probably is from upwelling of offshore water near 

the edge of the pack ice (Semmler, 2006). The percent of total mercury that is methylmercury 

increases from 3% in phytoplankton, to 7.6% in zooplankton, and more than 90% in arctic cod 

(Semmler, 2006), indicating that methylmercury is preferentially biomagnifying in this part of 

the Beaufort Sea food chain. Methylmercury was not measured in bowhead whale liver; because 

of the high selenium/total mercury ratio, most of the mercury in bowhead liver probably is 

present as an insoluble mercury-selenium complex (Dehn et al., 2006a). Three to 10% of the 

total mercury in ringed seal and polar bear liver is methylmercury; the remainder probably is 
172 

present as mercury-selenium complex (Woshner et al., 2001). Mercury concentrations in liver 

are much higher than those in other tissues of marine mammals. Thus, much of the 

methylmercury accumulated from zooplankton by bowhead whales and from arctic cod by 

beluga whales and ringed seals is demethylated and stored as a mercury-selenium complex, 

probably solid mercuric selenide, primarily in the liver (Khan and Wang, 2009). Thus, the 

apparent biomagnification of mercury in the trophic step from water-breathing prey to airbreathing predator is the result of assimilation of bioavailable methylmercury and chemical 

transformation of methylmercury to inorganic mercury and sequestration as solid mercuric 

selenide. 

3.5 16BEcology of the Kelp Community in the Stefansson Sound Boulder Patch 

3.5.1 64BStudy Design. 

The primary objective of cANIMIDA Task 6 was to use synoptic and long-term measurements 

of photosynthetically active radiation (PAR: the total radiation in the 400 to 700 nm wavelength 

interval), light attenuation coefficients, total suspended solids (TSS) concentration, and indices 

of benthic diversity and kelp biomass to determine the impact of sediment resuspension on kelp 

productivity and ecosystem status in the Stefansson Sound Boulder Patch (Dunton et al., 2009). 

This research project was designed to address ecosystem change as related to anthropogenic 

activities from offshore oil and gas development, particularly in the vicinity of the Liberty 

prospect. The initial effort in the ANIMIDA Project was focused on establishing a quantitative 

relationship between total suspended solids (TSS) and benthic kelp productivity (Aumack et al., 

2007). In cANIMIDA, the specific objectives included efforts to: 

 define the spatial variability in annual productivity and biomass of kelp 

 monitor incident and in situ ambient light (as photosynthetically active radiation [PAR]) 

and TSS; 

 establish the quantitative relationship between TSS, light attenuation, and kelp 

productivity; 

 measure benthic faunal community diversity; 

 incorporate historical datasets related to kelp productivity, ambient PAR measurements 

(both surface and underwater), and benthic diversity into ANIMIDA datasets to establish 

a long-term record available in digital format; and 

 develop a rationale and strategy for future Boulder Patch contaminant monitoring. 

 Thirty sites across the monitoring area (Figure 2-4) were sampled, in order to describe the 

spatial extent and patterns of TSS, light attenuation, chlorophyll, nutrients, and 

physiochemical properties across Stefansson Sound. 

3.5.2 65BLight Attenuation 

Because it is important to understand how changes in the light environment affect kelp 

productivity, we used surface light and underwater light to quantify the relationship between TSS 

and the attenuation coefficient, k (m-1). The light attenuation coefficient (k) is the fraction of 

radiant energy removed from light by either absorption or scattering per unit distance passed 

through the water column. k was derived from coincident in situ measurements of surface and 
173 

underwater PAR at 2 and 4 m depths collected at 30 stations (Figure 2-4) on three different 

occasions each summer. Attenuation was consistently elevated in coastal zones with highest k

values (1.4 m-1) observed near Endicott Island and the SDI, indicating more turbid water closer 

to shore (Figure 3-58). Lower k values (0.4 m-1) were recorded offshore along the eastern and 

northeastern sides of Stefansson Sound. In summer 2004, k ranged from 0.43 – 1.34 m-1 (mean 

0.73 ± 0.14) throughout Stefansson Sound. In 2005 k ranged from 0.47 – 1.32 m-1 (mean 0.69 ± 

0.03) and in 2006, k was 0.54 – 1.08 m-1 (mean 0.72 ± 0.01). The majority of the Boulder Patch, 

including areas with dense kelp populations (> 25% rock cover), were found predominantly in 

offshore waters where attenuation measurements were consistently less than 1.0 m-1. 

Figure 3-58. Combined mean attenuation coefficient (k) values calculated from measurements 

collected at 2 m and 4 m water depths in summers 2004, 2005 and 2006. Areas of 

>10% rock cover are outlined in black. From Dunton et al. (2009). 

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174 

Figure 3-59. Combined mean total suspended solids (TSS) mg/L from samples collected at 2 m 

and 4 m water depths in 2004, 2005 and 2006. Areas of >10% rock cover are outlined 

in black. From Dunton et al. (2009). 

 

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3.5.3 Total Suspended Solids (TSS) 

TSS concentrations were much lower in the summers of 2004 and 2006 (generally all 

<7.0 mg/L) than in 2005 (generally >7.0 mg/L), but the general trend of decreasing TSS with 

distance offshore was observed in all three years (Figure 3-59). Since a paired t-test indicated 

that the TSS values measured at 2 and 4 m depths were not significantly different in either 2004 

and 2005 (2004 p = 0.065; 2005 p = 0.156) the means of the two depths are displayed in 

Figure 3-59. In 2004, highest TSS concentrations (7.6 - 8.3 mg/L) were found near Endicott 

Island and SDI and in a turbid area just north of Narwhal Island (5.7 – 6.1 mg/L). TSS 

concentration ranged from 3.8 – 7.6 mg/L (mean 5.0 mg/L) outside the Boulder Patch. Inside the 

Boulder Patch TSS concentration ranged from 4.0 to 8.3 mg/L (mean 5.0 mg/L); the overall site 

average was 5.0 ± 1.8 mg/L. 

TSS measurements were much higher and variable throughout Stefansson Sound during the 

summer of 2005 (7.5 – 23.8 mg/L; mean 11.1 ± 1.1 mg/L). Highest values (17.6 – 23.8 mg/L) 

were located nearshore, adjacent to Endicott Island, SDI, and Point Brower. Outside the Boulder 

Patch, TSS concentrations ranged from 7.5 to 23.8 mg/L (mean 11.2 mg/L). Inside the Boulder 

Patch, concentrations ranged from 9.0 to 17.6 mg/L (mean 11.0 mg/L). 

TSS concentrations in 2006 were similar to those measured in 2004 (range 3.5 - 6.9 mg/L; mean 

4.7 ± 0.2 mg/L). The highest concentrations again were adjacent to Endicott Island, SDI and 

Point Brower. Outside the Boulder Patch, TSS concentration ranged from 3.6 to 6.9 mg/L (mean 

4.6 ± 0.2 mg/L). TSS ranged from 3.5 to 5.9 mg/L inside the Boulder Patch with a mean of 4.6 ± 

0.2 mg/L. 

3.5.4 67BChlorophyll a Concentrations 

Chlorophyll a measurements from 2 and 4 m depths were significantly different from each other 

in 2004 (p = 0.00006), 2005 (p = 0.008), and 2006 (p = 0.0000004). In all three years, 4 m 

chlorophyll concentrations were higher than the 2 m measurements. The 2005 chlorophyll means 

were the highest, followed by 2004 means, with the lowest values occurring in 2006. In 2004 

chlorophyll measurements ranged from 0.11 to 2.63 μg/L (mean 0.39 ± 0.2 μg/L). In summer 

2005, values ranged from 0.11 to 3.54 μg/L (mean 0.76 ± 0.08 μg/L) compared to 

0.11 – 0.41 μg/L (mean 0.18 ± 0.01 μg/L) in 2006. Highest concentrations were north of 

Narwhal Island in 2004 and in nearshore waters adjacent to Endicott and SDI in 2005 

(Figure 3-60). Chlorophyll a concentrations were low and quite uniform throughout the study 

area in 2006. 
176 

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Figure 3-60. Chlorophyll a concentrations (μg/L) measured in 2004, 2005 and 2006. Samples 

were collected at 4 m water depth. Areas of >10% rock cover are outlined in black. 

From Dunton et al. (2009). 

3.5.5 68BNutrient Concentrations 

Ammonium, phosphate, silicate, and nitrate + nitrite nutrients were analyzed in 2- and 4-m water 

samples collected in the three times in July and August 2004, 2005 and 2006 (Table 3-48). 

Ammonium concentrations were significantly lower in water samples collected at 2 m than in 

those from 4 m in 2004 and 2005, and significantly higher in 2006 (p = 0.024; p = 0.00009; p = 

0.00005) All mean concentrations were low, ranging from 0.12 to 0.65 μM. Highest 

concentrations were water samples at sites adjacent to barrier islands. 

 
177 

Table 3-48. TaConcentrations the primary nutrients, ammonium, phosphate, silicate, and nitrate 

+ nitrite at two depths in the water column at 30 sites in Stefansson Sound, measured on 

three occasions annually in July and August 2004 - 2006. Values are mean ± SE in μM. 

From Dunton et al. (2009). 

Inorganic Nutrient Depth (m) 2004 2005 2006 

Ammonium (NH4

+

) 

2 0.12 ± 0.06 0.40 ± 0.04 0.25 ± 0.05 

4 0.17 ± 0.07 0.65 ± 0.05 0.12 ± 0.02 

Phosphate (PO4

-3) 

2 0.24 ± 0.03 0.29 ± 0.01 0.17 ± 0.01 

4 0.19 ± 0.05 0.35 ± 0.01 0.20 ± 0.01 

Silicate (SiO4

-4) 

2 1.76 ± 0.18 5.64 ± 0.19 7.05 ± 0.14 

4 1.84 ± 0.26 5.19 ± 0.16 6.89 ± 0.16 

Nitrate + Nitrite 

(NO-3 + NO-2) 

2 0.14 ± 0.10 0.21 ± 0.04 0.07 ± 0.01 

4 0.15 ± 0.01 0.29 ± 0.08 0.10 ± 0.02 

Mean phosphate concentrations were low throughout the study area, ranging from 0.17 to 0.35 

μM (Table 3-48). Highest concentrations were in water samples collected at sites adjacent to 

Endicott. The lowest concentrations were in water samples from sites seaward of Narwhal 

Island. Phosphate concentrations were slightly lower in water from 4 m than from 2 m in 2004 

and slightly higher in water from 4 m than 2 m in 2005 and 2006. 

Mean silicate concentrations in water from both 2 and 4 m increased between 2004 and 2006 

(Table 3-48). Mean concentrations ranged from 1.76 μM at 2 m in 2004 to 7.05 μM at 2 m in 

2006. 

Concentrations of NO2

-

 + NO3

-

 were low throughout Stefansson Sound (Table 3-48). 

Concentrations ranged from 0.07 μM at 2 m in 2006 to 0.29 μM at 4 m in 2005. 

3.5.6 69BPhysicochemical parameters 

The four physiochemical parameters measured during synoptic water sampling included 

temperature, salinity, dissolved oxygen, and pH (Table 3-49). Mean seawater temperature at 2 m 

and 4 m increased throughout the Boulder Patch each year between 2004 and 2006. Summer 

2004 was characterized by frequent storm activity which was reflected to depressed surface 

water temperatures that were negative at some sites. The mean temperatures at 2 m and 4 m in 

2006 were more than 2-fold and 4-fold, respectively, higher than the mean temperatures at 2 and 

4 m in 2004. 

Salinity measurements were homogeneous across the Boulder Patch and means were consistent 

among the summers 2004 and 2005 at both 2 m and 4 m depths, but salinities dropped 

precipitously in 2006 (Table 3-49). In 2004, salinity ranged from 20.4 to 27.4‰ at 2 m and 23.5 

to 31.7‰ at 4 m. In 2006, salinity dropped to 11.3 to 23.5‰ at 2 m and 12.3 to 30.0‰ at 4m. 

Salinity was slightly lower at 2 m than at 4 m in all three years. 

 
178 

Table 3-49. Average temperature, salinity, dissolved oxygen, and pH at two depths in the water 

column at 30 sites in Stefansson Sound, measured on three occasions annually in July and 

August 2004 - 2006. Values are means ± SE. From Dunton et al. (2009). 

Parameter Depth (m) 2004 2005 2006 

Temperature (°C) 

2 2.11 ± 0.55 2.62 ± 1.07 4.64 ± 0.16 

4 0.88 ± 0.75 1.97 ± 1.32 4.21 ± 0.22 

Salinity (‰) 

2 23.80 ± 0.99 23.85 ± 1.66 16.91 ± 0.35 

4 26.81 ± 1.16 26.65 ± 1.36 20.67 ± 0.49 

Dissolved O2 

(mg/L) 

2 13.18 ± 0.35 11.48 ± 0.45 11.45 ± 0.02 

4 14.22 ± 0.38 11.53 ± 0.39 11.57 ± 0.05 

pH 2 8.19 ± 0.05 No sample 7.90 ± 0.01 

4 8.22 ± 0.04 No Sample 7.88 ± 0.01 

pH data were recorded in 2004 and 2006, but not in 2005, because the pH meter malfunctioned 

during the 2005 field season (Table 3-49). In 2004, Mean pH was remarkably constant at 

approximately 8.2 at both 2 and 4 m in 2004. Mean pH also was consistent between 2 and 4 m in 

2006, but pH was lower at about 7.9, about 0.3 pH units more acidic than in 2004. 

Mean dissolved oxygen concentrations were higher in 2004 than in 2005 and 2006 at both 2 and 

4 m water depths (Table 3-49). Mean dissolved oxygen concentrations ranged from 13.2 to 14.2 

mg/L at 2 and 4 m in 2004. Mean dissolved oxygen concentrations were lower in 2005 and 2006, 

about 11.5 mg/L at both 2 and 4 m. The higher concentrations of dissolved oxygen in 2004 than 

in 2004 and 2005 probably are related to the lower water temperatures recorded in 2004 than in 

2005 and 2006. However, the dissolved oxygen concentrations in all three years are at or above 

saturation at ambient salinity and temperatures. Oxygen saturation at the ambient seawater 

temperatures and salinities range from about 11.8 to 12.5 mg/L (Murray and Riley, 1969). 

Oxygen saturation may be caused by high primary production during the long daylight hours of 

the Arctic summer in the shallow Boulder Patch. 

3.5.7 70BContinuous Light Measurements 

PAR measurements were collected during summer 2004, 2005 and 2006 at three historic 

sampling stations in the Boulder Patch. PAR followed a typical cyclical pattern with terrestrial 

surface irradiances peaking between 1200 – 1400 μmol photons/m2

/sec. Surface irradiance 

maxima always occurred between 1300 and 1400 hrs. The highest underwater PAR values 

measured by the underwater spherical quantum sensors also normally occurred around 1400 in 

all three summers. Between 31 July and 6 August, 2004, underwater irradiance dropped to near 

zero at all three sites (DS-11, E-1, and W-1) in conjunction with a series of intense storms. 

Extremely low underwater PAR concentrations continued through 9 August followed by four 

days of slightly higher values, at which point the dataloggers were removed. Prior to the storm, 

underwater cosine sensors measured peak downward irradiances ranging from 180 to 200 

μmoles photons/m2/sec. In 2005, underwater PAR measurements were lowest between 15 July 

and 1 August although the surface irradiance was high on most days. In 2006, underwater PAR 

was lowest at W-1 but was generally consistent across all sites with no sustained periods of low 
179 

PAR. Values recorded from both surface and underwater PAR sensors are similar to irradiance 

measurements made in Stefansson Sound during earlier studies (Dunton, 1990). 

Overall, water transparency, as reflected by consistently low k values (generally < 1.0/m) and 

high light transmission (> 55%/m) at all three sites, was highest in 2006, probably due to the 

absence of significant storm events during the study period. In all three years, mean irradiance 

was significantly (p<0.05) lower at site W-1, the station farthest to the west, compared to all 

other sites for the period 26 July to 10 August although the surface irradiance was high on most 

days. Values recorded from both surface and underwater PAR sensors are similar to irradiance 

measurements made in Stefansson Sound during earlier studies (Dunton, 1990). Lowest light 

transmission (< 10%/m) and highest k values (2-3/m) were observed at all three sites in 2004. 

Conditions in 2005 improved considerably, with just one peak in water turbidity occurring in late 

July as noted earlier. The shallower depth at E-1, compared to W-1 and DS-11 amplifies the k

values at this site for similar levels of underwater PAR recorded at all three sites. 

3.5.8 71BKelp Measurements 

3.5.8.1 127BKelp Linear Growth 

Blade elongation in Laminaria solidungula displayed large spatial and temporal variability as 

reflected in measurements from eight sites between 1996 and 2006 (Figure 3-61). Growth was 

measured per growth year, defined as the period beginning on 15 November one year and ending 

on 15 November the following year. At these high latitudes, kelp stores nutrients produced by 

photosynthesis during the summer high solar irradience period and then uses the nutrients for 

new biomass growth during the dark winter months. Mean site blade growth was lower at every 

site in growth year 2003 compared to growth in all other growth years between 2000 and 2006, 

reflecting the exceptionally poor weather conditions in summer 2003 that produced extremely 

low levels of ambient PAR. Kelp collected in the three years of cANIMIDA (growth years 2003, 

2004, and 2005) had annual blade growth rates comparable to those recorded in earlier studies 

(LGL Alaska Research Associates Inc. and Dunton, 1992; Martin and Gallaway, 1994; Dunton 

and Dayton, 1995). An interannual comparison of growth years 1998 – 2005 at DS-11 and E-1 

indicated that linear growth was lowest during growth year 2003, highest in growth year 2000, 

and that 2005 was similar to 1998-2000. Changes in local climatology clearly have an important 

role in regulating kelp growth through increased cloud cover and sustained winds that negatively 

impact kelp growth (Figure 3-62). 
180 

Figure 3-61. Variation in annual growth in Laminaria solidungula from 1996 to 2006 at sites in 

the Stefansson Sound Boulder Patch. Measurements are based on blade lengths of 

plants collected between 2001 and 2006 under the ANIMIDA project. Values are 

means. From Dunton et al. (2009). 

3.5.8.2 128BKelp Biomass 

In the summer of 2005, Laminaria solidungula plants were measured in situ along four 25 m 

transects at sites DS-11 (n = 226) and E-1 (n = 53). A correlation coefficient between basal 

blade dry weight (g) and basal blade length (cm) developed for the Stefansson Sound Boulder 

Patch from specimens collected between 1980 and 1984 (n = 912) was used to obtain an estimate 

of kelp biomass at these sites. Biomass at DS-11 (> 25% rock cover) ranged from 5 to 45 g/m2

(mean 23 g/m2

) compared to a range of 0.5 to 2.7 g/m2 (mean 1.7 g/m2) at site E-1 (10-25% rock 

cover). The range of biomass at DS-11 is within the estimates reported by Dunton et al., (1982). 

Estimates of benthic biomass at the ANIMIDA sites in Stefansson Sound are critical for 

calculation of realistic basin-wide benthic production models in relation to changes in PAR. 
181 

Figure 3-62. Annual mean linear growth of Laminaria solidungula as a function of the number 

of hours that wind speed exceeded 10 m/s at SDI in July and August, 2001 to 2006. 

Wind speed data from Veltcamp and Wilcox, 2007. Sites DS-11 (blue) and E-1 

(green) are located in the Stefansson Sound Boulder Patch. From Dunton et al. (2009). 
182 

3.6 17Monitoring the Boulder Patch: Biodiversity Assessments 

3.6.1 72BIntroduction 

Marine biodiversity can be defined as the variety of living organisms within a particular marine 

ecosystem and the ecological communities they form. Biodiversity often is used as a measure of 

ecosystem health, though this sometimes is not the case, as in harsh Arctic marine environments. 

The seafloor of the nearshore Beaufort Sea is typically dominated by soft sediments (Barnes and 

Reimnitz 1974; Trefry et al., 2009). The benthic faunal communities in those sandy, silty or 

muddy sediments have a low biodiversity, dominated by bivalve mollusks, polychaete worms, 

and benthic amphipods (Feder and Schamel 1976, Carey and Ruff 1977, Carey et al. 1984). 

There are local hotspots of abundant and diverse marine life amidst these relatively low-diversity 

areas, where boulders provide rare hard substrates for colonization by macroalgae and sessile 

epibenthic (epilithic) macrofauna. One of these regions is the Boulder Patch in eastern 

Stefansson Sound. One of the main reasons why this area has been identified as a focus area 

within the cANIMIDA project is the need to protect these sensitive, biologically productive 

regions, while allowing oil exploration in the surrounding areas (Figure 3-63) (MMS, 2007). 

A variety of brown and red macroalgae have colonized the boulders in the Boulder Patch, 

forming one of the few known macroalgal beds along the Alaskan Arctic coast. Sessile fauna 

such as sponges, encrusting bryozoans, hydroids, soft corals, and tube worms thrive on the rocky 

and macroalgal substrates (Dunton et al. 1982, Dunton 1992, Konar and Iken 2005). This threedimensionally structured, epilithic community provides habitat for a number of associated 

macro-organisms. More than 150 species of macroalgae, invertebrates and fishes were found in 

the Boulder Patch in the late 1970s (Dunton et al. 1982; Dunton and Schonberg 2002), while 

only about 30 infaunal species, mainly polychaetes and amphipods, have been recorded from the 

adjacent soft-bottom areas in Prudhoe Bay (Feder and Schamel 1976). Thus, the Boulder Patch is 

a unique area of high biodiversity in the otherwise silt-mud dominated system of the Beaufort 

shelf that is devoid of the majority of these faunal and floral groups. 

The uniqueness of the Boulder Patch ecosystem made it a center-piece of Task 6 of both the 

ANIMIDA and cANIMIDA Projects (Dunton et al., 2004, 2009). The biodiversity assessment 

was introduced in the cANIMIDA Project. Biodiversity is one potential measure of ecosystem 

health and of biological interactions such as competition, disturbance, facilitation, predation, 

recruitment, and productivity of a system (Petraitis et al. 1989, Worm et al. 1999, Mittelbach et 

al. 2001, Paine 2002). The goal of this study was to establish the recent level of biodiversity of 

epilithic communities within the Boulder Patch with the purpose of evaluating further monitoring 

mechanisms for this sensitive habitat.

A total of seven Boulder Patch sites, established by Martin and Gallaway (1994), were sampled 

(Figure 3-64). Biodiversity samples were taken and processed between 30 July – 3 August 2005, 

and between 21 July – 31 July 2006. Sites were sampled following the standardized sampling 

protocols developed within the NaGISA program (Natural Geography in Shore Areas: Rigby et 

al. 2007), a field project within the Census of Marine Life (Uhttp://www.coml.org/U). See Dunton et 

al. (2009) for additional details. 
183 

Figure 3-63. Stefansson Sound, showing the Boulder Patch area in relation to the Liberty 

prospect and the Endicott and SDI production facilities. From MMS (2007). 

3.6.2 73BMacroalgal Communities 

Percent macroalgal cover at station DS11 was significantly different in the two years of the 

study. This difference was driven mainly by the abundance of red algae in both years (30% of 

dissimilarity between years). Percent cover also differed among sites (DS11, W3, E3) sampled in 

2006, which was due mainly to differences between E3 and the two other sites. This difference 

was based on a much higher percentage of gravel and lower rock cover at E3 compared to other 

sites. 
184 

Fifteen macroalgal species were collected in the Boulder Patch in both 2005 and 2006 

(Table 3-50). New records for the area include the brown algae Sphacelaria plumosa and 

Sphacelaria arctica, and the red algae Rhodomela tenuissima and Scagelia cf americana. Also, 

the red alga Phyllophora trucata often was infested with what has been identified so far as an 

endophytic Chlorochytrium. The sampling protocol was suitable to exhaustively measure 

macroalgal biodiversity as species accumulation curves reached asymptote with 4-6 replicates. 

Table 3-50. Species and distributions of major taxa of macroalgae in the Boulder Patch in 2005 

and 2006. From Dunton (2009). 

Division Species 2005 sites 2006 sites Comments 

Chlorophyta 

(green algae) 

Chaetomorpha 

melagonium (Weber et 

Mohr) Kützing 

E1, E2, W3 E1, E2 

Rhodophyta 

(red algae) 

Phycodrys riggii NL 

Gardner 

DS11, E1, E2, 

E3, W1, W2, W3 

DS11, E1, E2, 

E3, W1, W2, W3 

Rhodophyta 

(red algae) 

Phyllophora truncata

(Pallas) Zinova 

DS11, E1, E2, 

E3, W1, W2, W3 

DS11, E1, E2, 

E3, W1, W2, W3 

Rhodophyta 

(red algae) 

Dilsea socialis

(Postels et Ruprecht) 

Perestenko 

DS11, E1, E2, 

E3, W1, W2, W3 

DS11, E1, E2, 

E3, W1, W2, W3 

Rhodophyta 

(red algae) 

Odonthalia dentata

(Linnaeus) Lyngbye 

DS11, E1, E2, 

E3, W1, W3 

DS11, E1, E2, 

E3, W1, W2, W3 

Rhodophyta 

(red algae) 

Rhodomela sibirica

Zinova et KL 

Vinogradova 

DS11, E1, E2, 

E3, W1, W2, W3 

DS11, E1, E2, 

E3, W1, W3 

Rhodophyta 

(red algae) 

Rhodomela tenuissima

(Ruprecht) Kjellman 

E2 E1 

Rhodophyta 

(red algae) 

Ahnfeltia plicata

(Hudson) Fries 

E1, W3 DS11, E1, E2, E3 

Rhodophyta 

(red algae) 

Scagelia cf americana

(Harvey) Athanasiadis 

DS11 DS11 

Rhodophyta 

(red algae) 

Lithothamnium sp DS11, E2, E3, 

W1, W2, W3 

DS11, E2, E3, 

W1, W2, W3 

Particularly prominent 

at DS11, E3 and W3 

Ochrophyta 

(brown algae) 

Laminaria solidungula

(C Agardh) 

DS11, E1, E2, 

E3, W1, W2, W3 

DS11, E1, E2, 

E3, W1, W2, W3 

Ochrophyta 

(brown algae) 

Laminaria saccharina

(C Agardh) 

W3 DS11, E3, W1, 

W3 

Was observed but not 

quantitatively collected 

at DS11 in 2005 

Ochrophyta 

(brown algae) 

Alaria esculenta

(Linnaeus) Greville 

- DS11 Was observed but not 

quantitatively collected 

at DS11 in 2005 

Ochrophyta 

(brown algae) 

Sphacelaria plumosa

Lyngbye 

E1, E2, W2 DS11, E1, W1, 

W2, W3 

Ochrophyta 

(brown algae) 

Sphacelaria arctica

Harvey 

E1, E2 E1, E2 

 
185 

Figure 3-64. Map of the cANIMIDA Task 6 study area. The labeled stations are historic 

Boulder Patch stations that have been visited repeatedly since 1984, and resampled for 

biodiversity in 2005 and 2006. During summers 2004, 2005 and 2006, long-term 

light was measured at sites DS-11, E-1, and W-1; kelp blade length data were also 

collected at these sites. 

The main contributors to total biomass in both years and at all stations were the red algae 

Phycodrys riggii and Phyllophora truncata and the brown alga Laminaria solidungula. Smaller 

amounts of biomass were usually contributed by the three red algae Dilsea socialis, Odonthalia 

dentata and Rhodomela sibirica (Figure 3-64). 

Total macroalgal biomass was higher in 2006 than in 2005 at all sites (Figure 3-64, p<0.001, ttest), although relative proportions among sites were similar in both years. This higher biomass 

was particularly obvious at stations W2 and W3, that was driven mainly by significantly higher 

biomass contributions of P. riggii and P. truncata (p=0.033 and 0.005, t-tests) and also L.

solidungula (ns, t-test), in 2006. 

!

!

!

!

!

!

!

! !

!

W-2

W-1

W-3

E-1

E-2

E-3

DS-11

Brower-1

L-1

L-2

/

048 2

Kilometers

Cross Island

North Slope

Alaska

Narwhal

Island

SDI

Endicott

Pt. 

Brower
186 

Overall algal community structure based on biomass did not differ among sites within a year. If 

averaged by sites, none of the sites differed significantly in 2005 (p>0.05, SIMPROF test) but 

DS11 and W3 clustered differently from other sites in 2006 (Figure 3-65). In an interannual 

comparison (2-way crossed ANOSIM with sites and years as factors), sites had a larger influence 

on overall differences than year (Rglobal between years (across sites) = 0.103; Rglobal between sites 

(across years) = 0.31). 

3.6.3 74BEpibenthic and Epilithic Invertebrate Communities 

A total of 86 invertebrate species or higher taxonomic groups were identified in 2005 and 120 in 

2006. Of the 86 taxa in 2005, 21 were not found in 2006 and of the 120 taxa in 2006, 47 were not 

found in 2005. In the two collection years combined, 141 invertebrate taxa were identified. Taxa 

encountered in only one year were always rare and never dominant in either biomass or 

abundance. Invertebrates belonged to eight major phyla: Porifera, Cnidaria (Anthozoa, 

Hydroidea), Mollusca (Polyplacophora, Gastropoda, Bivalvia), Annelida (Polychaeta), 

Arthropoda (Pycnogonidae, Amphipoda, Isopoda, Cumacea, Decapoda, Cirripedia, [in 2006 also 

Copepoda, Insecta and Acari]), Bryozoa, Echinodermata (Asteroidea), and Tunicata 

(Ascideacea). 

Average invertebrate biomass (across all sites) was very similar between both years (15.96 g 

wet/m2 in 2005; 14.77 g wet/m2 in 2006). Invertebrate biomass in both years was clearly 

dominated by sponges, bryozoans and hydrozoans (Figure 3-66). 

Invertebrate abundance averaged across sites within a year was much higher in 2006 (56.08 

ind/m2

 in 2005 versus 207.26 ind/m2 in 2006) than in 2005, which was entirely driven by the 

very large numbers of barnacles in some replicates at sites E1 and E2. Abundance was 

dominated by polychaetes, bivalves and barnacles (Figure 3-65). Within the first two groups, it 

was one taxon each that caused high abundances, the serpulid worm, Spirorbis sp., and the 

mussel, Musculus sp. This overall pattern does not include non-countable encrusting and colonial 

organisms such as sponges, bryozoans, hydrozoans, and ascidians, which made up much of the 

biomass. Sites E1 and E2 differed most from other sites in both years because of high 

abundances of bivalves (Musculus sp) in 2005 (Figure 3-67a) and high abundances of barnacles 

in 2006 (Figure 3-67b). 

Invertebrate community composition based on biomass did fall into distinct groupings in 2005, 

but all station E-sites were distinctly different from other sites in 2006. This separation of station 

E-sites in 2006 was mostly due to the high biomass of barnacles and bivalves at these sites, as 

well as a lower biomass of polychaetes compared to the other sites. Community composition 

based on abundance differed most between sites E1 and E2 and the other sites in both years. In 

2005, these two station groupings were similar only at a 30% similarity level, and in 2006 at a 

35% similarity level. In both years, this dissimilarity between E1 and E2 and the other sites was 

driven by the high abundance of barnacles and bivalves. 

Dissimilarity between invertebrate communities (based on biomass) at different sites was mainly 

driven by the following species: Eucratea loricata (Bryozoa), Sertularia albimaris and S. 

cupressoides (both Hydrozoa), Haliclona gracilis and H. panicea (Porifera), and to a lesser 

extent the two polyplacophorans Ishnochiton albus and Amicula vestita. Community 
187 

composition based on abundance was mainly distinguished by Balanus crenatus (Cirripedia), 

Musculus spp. (Bivalvia), and Spirorbis sp. and Exogone spp. (Polychaeta). 

Figure 3-65. Absolute contribution of species to total macroalgal biomass (g ww/0.25m2

) across 

sites in 2005 and 2006. Note difference in scale in the two years. 

From Dunton et al. (2009). 

 

2005

0

10

20

30

40

50

60

70

80

90

100

DS11 E1 E2 E3 W1 W2 W3

sites

others

L. solidungula

Rhodomela sibirica

Odonthalia dentata

Dilsea socialis

Phyllophora truncata

Phycodrys riggii

Wet weight (g/0.25m2 )

2006

0

50

100

150

200

250

300

350

DS11 E1 E2 E3 W1 W2 W3

sites

Wet weight (g/0.25m2 )

2005

0

10

20

30

40

50

60

70

80

90

100

DS11 E1 E2 E3 W1 W2 W3

sites

others

L. solidungula

Rhodomela sibirica

Odonthalia dentata

Dilsea socialis

Phyllophora truncata

Phycodrys riggii

Wet weight (g/0.25m2 )

2006

0

50

100

150

200

250

300

350

DS11 E1 E2 E3 W1 W2 W3

sites

Wet weight (g/0.25m2 )

2006

0

50

100

150

200

250

300

350

DS11 E1 E2 E3 W1 W2 W3

sites

Wet weight (g/0.25m2 )
188 

Figure 3-66. Relative biomass contributions of major invertebrate taxa in a) 2005 and b) 2006. 

“Others” includes Anthozoa, Crustacea, Echinodermata and Nemertea. 

From Dunton et al. (2009). 

 

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

others

Cirripedia

Isopoda

Amphipoda

Polyplacophora

Bivalvia

Polychaeta

Bryozoa

Hydroidea

Porifera

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

a

b

relative biomass (%) relative biomass (%) 

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

others

Cirripedia

Isopoda

Amphipoda

Polyplacophora

Bivalvia

Polychaeta

Bryozoa

Hydroidea

Porifera

others

Cirripedia

Isopoda

Amphipoda

Polyplacophora

Bivalvia

Polychaeta

Bryozoa

Hydroidea

Porifera

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

a

b

relative biomass (%) relative biomass (%) 
189 

Figure 3-67. Relative abundance contributions of major invertebrate taxa in a) 2005 and b) 

2006. Encrusting and colonial taxa are excluded. “Others” includes Anthozoa, 

Crustacea, Echinodermata and Nemertea. From Dunton et al. (2009). 

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

Others

Cirripedia

Isopoda

Amphipoda

Polyplacophora

Bivalvia

Polychaeta

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

a

b

relative abundance (%) relative abundance (%)

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

Others

Cirripedia

Isopoda

Amphipoda

Polyplacophora

Bivalvia

Polychaeta

0

20

40

60

80

100

DS11 E1 E2 E3 W1 W2 W3

a

b

relative abundance (%) relative abundance (%)
190 

3.6.4 75BBiodiversity of the Benthic Community of the Boulder Patch 

Algal and invertebrate biomass was not significantly correlated (Pearson correlation, α=0.05) in 

either year. Separation of invertebrates into functional groups (mobile, sessile) also did not yield 

any significant relationship with macroalgal biomass. 

Diversity measures based on combined invertebrate and algal biomass data did not differ among 

sites within a year or between years (Table 3-51). Maximum possible Shannon-Woener diversity 

indices are 1.99 for 2005 and 2.17 for 2006, indicating that Shannon diversity values 

encountered in our samples were intermediate. Similarly, Simpson dominance indices also were 

about half the maximum possible values (0.99 in both years). Evenness (Pielou’s index), which 

is always constrained between 0 and 1, had values that were in the lower range owing to the fact 

that most species, especially among the invertebrates, had a highly uneven abundance 

distribution. 

Table 3-51. Shannon-Wiener diversity index, Simpson dominance index, and Pielou's evenness 

index for epilithic (living on hard substrates) communities (invertebrates and algae) in the 

Boulder Patch in 2005 and 2006. From Dunton et al. (2009). 

Site 

2005 2006 

Shannon Simpson Pielou Shannon Simpson Pielou 

DS11 1.118±0.47 0.640±0.37 0.449±0.18 1.298±0.39 0.623±0.17 0.431±0.10 

E1 1.061±0.28 0.579±0.16 0.446±0.12 1.169±0.19 0.609±0.08 0.449±0.07 

E2 0.777±0.40 0.457±0.26 0.372±0.17 1.107±0.45 0.569±0.20 0.444±0.16 

E3 0.821±0.28 0.616±0.31 0.391±0.12 1.021±0.32 0.554±0.15 0.429±0.19 

W1 1.037±0.26 0.668±0.15 0.493±0.12 1.081±0.38 0.612±0.29 0.391±0.14 

W2 1.119±0.27 0.619±0.16 0.473±0.11 0.889±0.34 0.479±0.18 0.287±0.11 

W3 1.057±0.46 0.641±0.38 0.467±0.21 1.097±0.23 0.570±0.13 0.401±0.08 

Annual 

average 

0.999±0.14 0.603±0.07 0.442±0.04 1.095±0.13 0.574±0.07 0.405±0.04 

While overall diversity indices did not differ among sites or between years, diversity of algae and 

invertebrates differed within each year. In both years, the Shannon diversity was significantly 

higher for invertebrates than for algae (p<0.001 for both years), although Pielou’s evenness 

index was higher in algae than in invertebrates (not significant in 2005, p<0.001 in 2006). 

Therefore, while the invertebrate portion of the community was much more diverse than the 

algal portion, the abundance of algal taxa was much more evenly distributed than invertebrate.

Core samples generally contained few species, low biomass, and low abundance of invertebrate 

species in both years. Several core replicates did not contain any organisms in 2005 (54%) and 

no invertebrates were found in any of the cores at W1 in 2005. More infauna were found in 2006 

when only 3 replicates (8.5%) did not contain any invertebrates and invertebrates were found in 

at least several of the replicates at all sites. Only 17 taxa were found in 2005; 11 were 

polychaetes and 3 were bivalves. In contrast, 42 taxa were identified from core samples in 2006; 

28 were polychaetes and 7 were bivalves. Core biomass in both years was dominated mainly by 

bivalves (Figures 3-68 and 3-69). Abundance in 2005 was dominated by polychaetes and at some 

stations by anthozoans and tanaids, and in 2006 by polychaetes, amphipods and tanaids. 
191 

Figure 3-68. Biomass (a) and abundance (b) of invertebrate taxa in sediment cores collected in 

the Boulder Patch in 2005. From Dunton et al. (2009). 

 

a

0.01

0.02

0.03

DS11 E1 E2 E3 W1 W2 W3

Tanaidacea

Bivalvia

Polychaeta

Hydroidea

Anthozoa

Tanaidacea

Bivalvia

Polychaeta

Anthozoa

0

0.1

0.2

0.3

DS11 E1 E2 E3 W1 W2 W3

b

Biomass (g wet weight/59cm3) Abundance (# individuals/59cm3) a

0.01

0.02

0.03

DS11 E1 E2 E3 W1 W2 W3

Tanaidacea

Bivalvia

Polychaeta

Hydroidea

Anthozoa

Tanaidacea

Bivalvia

Polychaeta

Anthozoa

0

0.1

0.2

0.3

DS11 E1 E2 E3 W1 W2 W3

b

Biomass (g wet weight/59cm3) Abundance (# individuals/59cm3) 0.01

0.02

0.03

DS11 E1 E2 E3 W1 W2 W3

Tanaidacea

Bivalvia

Polychaeta

Hydroidea

Anthozoa

Tanaidacea

Bivalvia

Polychaeta

Anthozoa

0

0.1

0.2

0.3

DS11 E1 E2 E3 W1 W2 W3

b

Biomass (g wet weight/59cm3) Abundance (# individuals/59cm3)
192 

Figure 3-69. Biomass (a) and abundance (b) of invertebrate taxa in sediment cores collected in 

the Boulder Patch in 2006. From Dunton et al. (2009). 

3.6.5 76BDiscussion 

The Boulder Patch is an isolated macroalgal-dominated rocky bottom habitat within the usually 

soft-sediment environment of the nearshore Beaufort Sea. Such algal systems are known to fulfill 

many diverse habitat functions in other regions of the world’s coastal oceans, such as providing 

three-dimensional space, protection, food, and nursery areas for juvenile life stages (e.g., Iken 

1999; Iken et al. 1997; Dean et al. 2000; Beck et al. 2003). These habitat provisions often 

0.002

0.004

0.006

0.008

0.010

0.012

0.014

DS11 E1 E2 E3 W1 W2 W3

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

a

Biomass (g wet weight/59cm3)

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

1

2

3

DS11 E1 E2 E3 W1 W2 W3

Abundance (# individuals/59cm3) b

0.002

0.004

0.006

0.008

0.010

0.012

0.014

DS11 E1 E2 E3 W1 W2 W3

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

a

Biomass (g wet weight/59cm3)

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

1

2

3

DS11 E1 E2 E3 W1 W2 W3

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

Ascideacea

Tanaidacea

Cumacea

Amphipoda

Bivalvia

Polychaeta

1

2

3

DS11 E1 E2 E3 W1 W2 W3

Abundance (# individuals/59cm3) b
193 

increase the number of associated fauna within such algal habitats (Taylor, 1998). In the Boulder 

Patch, for example, an important portion of carbon channeling through the Boulder Patch food 

web is derived from macroalgae (Dunton and Schell 1987). However, the lack of correlation 

between algal and invertebrate biomass found here indicates that flora and fauna are at least in 

part responding to different environmental drivers. 

Environmental factors influencing macroalgae in general are mostly light, nutrients, 

sedimentation, competitive interactions, and grazing pressure (Worm et al. 1999; Burkepile and 

Hay 2006; Liess and Kahlert 2007; Gruner et al. in press), all of which can work at the adult or 

early life history stages of algae. In the Boulder Patch, low light limits growth of kelp in the 

winter when nutrient levels are high and low nutrients limit summer growth when light levels are 

high (Dunton and Schell 1986). However, even in summer, light levels can be severely 

compromised locally by high loads of suspended particles in the water column from river 

discharge or resuspension due to storm events (Aumack et al. 2007). Sedimentation rate in the 

Boulder Patch can be high, as can be observed from the large build-up of fine sediments on top 

of boulders and algal thalli (Iken, pers. obs.). Detrimental effects of sedimentation for 

macroalgae include light reduction, smothering of small stages, and abrasion of microscopic life 

stages important for dispersal and recolonization (Kendrick 1991, Konar and Robert 1996, 

Airoldi and Cinelli 1997). Macroalgae also are under competitive constraints for space as many 

other encrusting organisms (mainly invertebrates) are competitively dominating in these 

interactions (Konar and Iken 2005). Grazers can have strong structuring effects on macroalgal 

communities in temperate and tropical ecosystems (e.g., Schiel and Foster 1986) but little is 

known about their influence on algal community structure in the Arctic (Konar 2007). In the 

Antarctic, several invertebrate and fish species are known to be algal consumers with the 

potential to influence biomass and species distribution (Iken 1999, Iken et al. 1997). Unique to 

polar environments, ice gouging also can have a considerable impact on algal communities as 

grounding ice can overturn large boulders and bury attached organisms but also expose new 

substratum (Conlan et al. 1998). In the Boulder Patch, such overturning events can be inferred 

from the occurrence of bleached (dead) encrusting coralline algae at the underside of boulders 

(Dunton et al. 1982). 

The diversity indices reported here are subject to change based on final confirmation of the 

taxonomic identity of some of the red algae. For example, there has been debate and 

considerable uncertainty regarding the genera Rhodomela, Phycodrys and Dilsea. The changes in 

species names between this report and those reported by Dunton et al. (1982) and Dunton and 

Schonberg (2000) include Rhodomela sibirica and/or R. tenuissima (from R. confervoides), 

Phycodrys riggi (from P. rubens), and Dilsea socialis (from D. integra). These changes either 

reflect (1) a definite shift in species composition over the last two decades which can be 

interpreted as possible effects of climate change or simply (2) disagreement among algal 

taxonomists regarding these particular genera (confirmation by S. Lindstrom here vs. R.T. Wilce 

in previous studies; note that in contrast, S. Schonberg has participated in all the taxonomic 

studies of the Boulder Patch fauna to date). 

The macroalgal community in the Boulder Patch in 2005 and 2006 was characterized by high 

biomass compared to invertebrate biomass, relatively even distribution (high Pielou’s index) and 

relatively low diversity measures. This pattern was caused mainly by the high occurrence of the 

two dominant red algae at all sites, Phycodrys riggii (possibly P. rubens) and Phyllophora 
194 

truncata. It seems that these species are competitively dominants and are able to capitalize on the 

available space (Konar and Iken 2005). It also may indicate higher reproductive success in these 

species, possibly through vegetative regrowth in addition to sexual reproduction. The abundance 

of Phycodrys riggii (or P. rubens) and Phyllophora truncata at all sites and independent of year 

indicates that environmental conditions for the most part are suitable to sustain these species. In 

contrast, some of the rarer species may not only be less competitive but may also be more limited 

by physiological constraints in the environment, such as low growth and reproduction due to low 

light or high sedimentation (Dunton and Schell 1986, Dunton and Dayton 1995). 

The algal species that showed distinct differences among sites was the kelp, Laminaria 

solidungula. This may indicate that kelp is more sensitive than other species to local 

environmental conditions. While overall environmental conditions in the Boulder Patch are 

relatively similar, there are distinct local differences in light and sedimentation regime, which 

probably are reflected in differences in kelp biomass. Laminaria solidungula is a perennial 

species but produces distinct annual blade sections during the winter, which are indicative of the 

light conditions experienced the previous summer (Dunton and Schell, 1986). If conditions were 

to change over time, this probably could be traced by diminished or increased kelp biomass. It 

has to be cautioned, however, that recruitment patterns and inter-annual variability in recruitment 

and post-recruitment mortality may influence adult distribution patterns. Current knowledge is 

that recruitment of all taxa is very slow in the Boulder Patch (Dunton et al., 1982; Konar 2007). 

It is suggested here that L. solidungula may be particularly suitable as an environmental indicator 

for monitoring purposes, as also investigated by other activities within cANIMIDA Task Order 6 

(for example, see Aumack et al. 2007). 

Compared to other geographical regions, macroalgal biomass and diversity are lower than occurs 

in cold-temperate waters along south-central Alaskan coasts in the northern Gulf of Alaska 

(Konar et al. 2009). There, macroalgal biomass at the same depth as the Boulder Patch is about 

an order of magnitude higher with about 100 g wet weight 0.25 m-2, compared to an average of 

about 10 g wet weight 0.25m-2 in the Boulder Patch. Also macroalgal diversity is higher in the 

Gulf of Alaska with 20-50 macroalgal species at 5 m depth, depending on location (Konar et al. 

2009). Comparative quantitative macroalgal data from other Arctic regions are rare, but species 

diversity in the Boulder Patch seems to be similar to that encountered along the Russian Arctic 

coast where kelps like Saccharina latissima, Laminaria digitata, Alaria esculenta and 

Saccorhiza dermatodea dominate the subtidal community (Tzetlin et al. 1997) and red algae such 

as Phycodrys rubens as well as Odonthalia dentata, Ahnfeltia plicata, Palmaria palmata, and 

Devaleraea ramentacea build much of the understory (Makarov et al. 1999). Also, the seaweed 

flora of the Canadian high Arctic, mainly the Baffin Bay area, are similar to that found in the 

Boulder Patch sublittoral kelp zone contains Saccharina latissima, Laminaria solidungula and 

also the red algae Dilsea integra, Devaleraea ramentacea, Rhodomela confervoides, other brown 

algae such as Punctaria glacialis, Desmarestia sp. and Chorda sp, and green algae of the genus 

Chaetomorpha (Ellis and Wilce 1961; Cross et al. 1987). In comparison, species diversity in 

western Svalbard is much higher, likely because of the strong influence of Atlantic species 

carried in by the Gulf Stream (Hop et al. 2002). 

The epilithic invertebrate community in the Boulder Patch had distinctly different characteristics 

than the macroalgal community. Invertebrate biomass was much lower than for algae; however, 

this is not unusual in systems where algae are the foundation taxon. The invertebrate community 
195 

had significantly higher diversity and lower evenness indices than the algal community. This is 

caused by the patchy distribution of invertebrates in the Boulder Patch with many rare taxa and 

some taxa being extremely abundant on small spatial scales. This small scale can be at the size of 

individual boulders, as exemplified by the two orders of magnitude higher barnacle abundance in 

two replicates at E2 in 2006 than in any other sample. Similarly, high patchy abundances in some 

but not all replicates per site were found for the bivalve, Musculus sp. at the E1 site in both years. 

Other invertebrate taxa seem to vary on slightly larger spatial scales than barnacles and bivalves. 

For example, sponges, hydroids and bryozoans always contributed considerably to invertebrate 

biomass at all sites and usually occurred regularly in most replicate samples within a site. 

Some bryozoans, hydroids, and sponges were identified in the present study to be major drivers 

of differences in invertebrate community composition among sites (Eucratea loricata, Sertularia 

spp., Haliclona spp.). Similarly, some polychaetes, bivalves, and barnacles were important in 

differentiating among sites when invertebrate abundances were regarded. As discussed above for 

macroalgae, it is these differentiating species that probably will make good monitoring species 

(indicator species) as they probably are responding to different environmental conditions on the 

scale of sites within the Boulder Patch, and may respond to changing environmental conditions. 

As the kelp Laminaria solidungula, these invertebrates are long-lived, which should dampen 

some of the effects that inter-annual variability in recruitment and post-recruitment mortality 

have on adult abundance. However, more information is needed on the specific effects that 

environmental conditions have on recruitment processes and how this could influence patterns 

detected from monitoring adult populations. If cost-effective monitoring efforts are to be 

developed, especially the sessile species should be considered as likely candidates as they can be 

distinguished readily in situ, thus avoiding labor-intensive scrape collections and timeconsuming identifications in the laboratory. It is suggested here that feasible monitoring efforts 

can be done effectively by quantitative percent cover estimates using SCUBA. Naturally, the 

details of such monitoring design would need to be rigorously tested in future work. 

In a larger geographical comparison, a similar invertebrate taxon composition was found to be 

associated with macroalgae in an Arctic fjord in Spitsbergen (Lippert et al. 2001). While actual 

species were different, sponges, hydroids and bryozoans were important sessile taxa and were 

represented in similar species numbers as in the Boulder Patch. Among the mobile fauna, 

polychaetes, bivalves and amphipods were the most speciose groups in Spitsbergen, which is 

similar to our results from the Boulder Patch, although amphipods seemed to be more species 

rich in Spitsbergen. Similarly high amphipod species numbers were found in Bjornøya, close to 

Spitsbergen (Weslawski et al. 1997). It may be that amphipods may be more dominant in Arctic 

regions under Atlantic influence, or that local differences in habitat structure (e.g. high 

abundance of filamentous green algae, Lippert et al. 2001) favor amphipods in the Spitsbergen 

regions. 

Infaunal abundance in the Boulder Patch was very low and there were distinct differences 

between the two sampling years. It is suggested here that these interannual differences likely 

stem from methodological differences applied in both years. The sediment in the Boulder Patch 

is highly consolidated and contains a high percent clay, which presented difficulties during the 

sieving process when clay portions were broken up. We assume that organisms were lost during 

the sieving process in 2005. In 2006, we employed a more gentle method by slowly stirring 

sediments in large volumes of water until clay clumps dissolved. While we believe this has 
196 

resulted in much better capture of the infaunal community, it is not a feasible method that could 

be employed routinely for large sample quantities. It also is possible that much of the infauna of 

these fine-grained, consolidated sediments were smaller than the 500 μm screen used to collect 

infauna. Thus, the total infauna were undersampled. 

3.6.6 7BComparison with Pre-ANIMIDA Data 

Both epilithic taxon composition as well as relative contributions of different taxa to the overall 

community are similar to what has been reported previously (Dunton and Schonberg, 2000) with 

mollusks and polychaetes being dominant taxa based on abundance. Sponges, hydroids, 

bryozoans and ascideans are major contributors to invertebrate biomass, as also identified by 

Dunton and Schonberg (2000). The total number of epilithic invertebrate taxa identified here 

(~140) was much higher than previously found by Dunton et al. (1982) and Martin and Gallaway 

(1994), which is mainly due to the lack of polychaetes reported in those studies. The taxon 

number was similar though to those reported by Dunton and Schonberg (2000) for “between 

rocks infauna”, which included a significant amount of epifaunal organisms. In all studies, 

however, the main biomass and abundance contributors were the same and differences existed 

mainly for the rarer taxa. 

Infaunal species biomass was similar to earlier results for infauna between rocks (Dunton and 

Schonberg, 2000). In both studies, mollusks (mainly bivalves) were the main biomass 

contributor (only 2006 results considered here), followed by polychaetes. Remaining taxonomic 

groups differed between studies but this was likely due to the very low presence of other taxa, 

which may be too patchily distributed to be sampled effectively by a limited number of small 

cores. However, overall infaunal taxon richness was only about half of what was found during 

the Dunton and Schonberg (2000) study. Sampling effort was larger in the previous study as a 

much larger core (0.01m2

 area versus 0.001m2 area) was used and sampled with an airlift, likely 

contributing to some of the observed differences. Mesh size, another important factor when 

comparing community composition, was the same in both studies (500 μm) and thus did not 

contribute to differences in infaunal diversity between the studies. 

In summary, the Boulder Patch is characterized by high diversity, abundance and biomass of 

macroalgae and invertebrates compared to the surrounding soft sediments. Both macroalgal and 

invertebrate components of the community are dominated by few, very common species. 

Interestingly, some of these species have distinct site distributions within the Boulder Patch, and 

if these distributional patterns can be linked to major environmental factors such as light 

availability or sedimentation, then these species may be good candidates for monitoring 

purposes. 

3.7 18BMonitoring Subsistence Bowhead Whaling near Cross Island, 2001-2007 

3.7.1 78BThe Bowhead Whale Balaena mysticetus

Bowhead whales are found only in Arctic and subarctic regions. They spend much of their lives 

in and near the pack ice, migrating to the high Arctic in summer, and retreating southward in 

winter with the advancing ice edge (Allen and Angliss, 2009). 

The International Whaling Commission (IWC) currently recognizes four stocks: BeringChukchi-Beaufort Seas (northern Alaska, western Canada, and eastern Russia); Hudson Bay-
197 

Foxe Basin (Canada) and Davis Strait-Baffin Bay (Denmark (Greenland) and Canada) [now: 

East Canada-West Greenland stock]; Svalbard-Barents Sea (Spitsbergen) (Denmark (Greenland), 

Norway, and western Russia); and the Okhotsk Sea (Russia and Japan) (OSPAR, 2010). 

The Bering-Chukchi-Beaufort Seas stock of bowhead whales is distributed in seasonally icecovered waters of the Arctic and near-Arctic, generally north of 60°N and south of 75°N in the 

western Arctic Basin (Allen and Angliss, 2009). This stock occupies marine waters from 

Chaunskaya Guba (Russia) in the western Chukchi Sea east to the Amundsen Gulf (Canada), and 

from the northern Bering Sea south to Karaginskiy Zaliv (Russia), St. Matthew Island, and 

Norton Sound (OSPAR, 2009). The size of the Bering-Chukchi-Beaufort Seas stock has grown 

steadily since the ban on commercial whaling to an estimated size of 10,545 (CV 0.128) 

individuals in 2001 and an annual rate of population increase of about 3.5% (Brandon and Wade, 

2006; Allen and Angliss, 2009). 

3.7.2 79BObjectives 

Monitoring of subsistence bowhead whaling near Cross Island was initiated as Task 4 of the 

ANIMIDA Project (Galginaitis, 2004; Galginaitis and Funk, 2004) and has continued as Task 7 

of the cANIMIDA Project (Galginaitis, 2009). Data were collected for the fall whale hunts of 

2001 through 2007. The overall objective of this project was to describe subsistence whaling as 

currently conducted near Cross Island by residents of Nuiqsut. The project was designed as a 

collaborative effort among MMS (through M. Galginaitis, Applied Sociological Research), the 

subsistence whalers, and the Alaska Eskimo Whaling Commission (AEWC). This project was 

designed to measure basic parameters of Cross Island whaling so that observed changes (if any) 

in subsistence whaling activities could be analyzed in relation to such factors as offshore oil and 

gas activities, weather and ice conditions, climate change, or other variables. 

3.7.3 80BContemporary Subsistence Whaling in Alaska 

This report concentrates on fall whaling by Nuiqsut residents, currently conducted from and near 

Cross Island, due to the specific interest in the potential effects of offshore oil and gas activities 

on subsistence whaling. Cross Island is the closest whaling site to most of the past offshore 

exploratory drilling in the Alaskan Beaufort Sea and the current development and production 

activities at Endicott, Northstar, and Liberty (Figure 2-3). The island lies at the western border of 

Stefansson Sound and a short distance west of the Boulder Patch and about 16 km northwest of 

Endicott production island (Figure 3-63). 

The Inupiat of the North Slope maintain and live a vital culture -- with kinship, dependence on 

hunting wildlife resources, and a respectful relationship to the land as fundamental values. 

Hunting provides most of the meat consumed by Inupiat. Whaling not only provides a significant 

part of this food, but also is a key social organizational activity for North Slope Inupiat. Whaling 

also is a central ideological idiom for the expression of key cultural values, and an important 

vehicle for the transmission of those values (Worl 1979; Rexford 1997). Subsistence whaling has 

been (and continues to be) a key focus for Inupiat and Yupik culture and society (Bering Straits 

area, Northern coastal Alaska) for at least 1,000 to 1,500 years (Dumond 1984; Krupnik and 

Stoker 1993; McCartney 1994). This discussion focuses on a general description of some key 

aspects of the organization of subsistence whaling, within the context of its management regime, 

that are important for an understanding of this project’s methods and results. 
198 

In Alaska, eleven coastal communities (Point Lay recently being allocated a quota of one 

bowhead whale per season) currently field whaling crews and are members of the AEWC. 

Subsistence whaling in Alaska occurs in the spring (generally April-May) in the Bering 

Straits/Chukchi Sea and the fall (generally September-October) in the Beaufort Sea, when the 

bowhead whale migration brings them reasonably close to the whaling communities in those 

areas. Barrow, located where the Chukchi Sea and the Beaufort Sea meet, has historically whaled 

in both seasons. In the spring, bowhead whales migrate north through the Bering Straits into the 

Chukchi Sea, past Barrow into the Alaskan Beaufort Sea, and then, into the Canadian Beaufort 

Sea and Amundsen Gulf, where they spend the summer feeding (some may also go west from 

the Chukchi Sea into Russian waters). In the fall they reverse this course. Figure 3-70 is a map 

showing these migratory routes and the locations of the 11 Alaskan (and six Russian) whaling 

communities and the seasonal availability of bowhead whales to each of the whaling communities. Use areas for Point Lay and the Russian communities are not indicated on Figure 3-70, 

because whaling for bowhead whales has only recently resumed from those locations. 

Figure 3-70. . A map showing the generalized spring (eastward) and fall (westward) bowhead 

whale migration routes and locations of Alaskan subsistence whaling communities. 

The draft map was prepared by the National Science Foundation, the Barrow Arctic 

Science Consortium, and the North Slope Borough. From Galginaitis et al. (2009). 

Spring whaling differs from fall whaling. In the spring, whales migrate through relatively narrow 

open leads in the ice, whereas in the fall, the water usually is more open (although there often are 
199 

large areas of thick floating ice). Spring leads do not open up close enough to Nuiqsut or 

Kaktovik along the central Alaskan Beaufort Sea coast to allow these communities to whale in 

the spring. In the fall, because whales are not confined by leads, it is difficult in most years for 

whaling communities southwest of Barrow to whale (although St. Lawrence Island and 

Wainwright whalers have taken a few whales in the fall), because the whales are so far offshore 

at those points. Thus, most whaling communities whale in the spring, while Barrow can hunt 

whales in both the spring and the fall, and Nuiqsut and Kaktovik whale only in the fall. Spring 

whalers have traditionally and historically used only skin boats (until recently), whereas fall 

whalers use more durable wood, aluminum, and fiberglass boats. This is related to three general 

seasonal differences: the greater need to avoid unnecessary noise in the spring, the harsher 

environmental conditions of fall whaling (rougher seas, more floating ice), and the greater need 

for speed in the fall to find and pursue whales in more open water. 

In 1978, the International Whaling Commission (IWC) set a low quota of bowheads that could 

be harvested, because of concern that the bowhead population was too small to sustain a regular 

harvest and subsistence whaling methods were too wasteful. The quota was accompanied by a 

monitoring program to measure and monitor the bowhead whale population and the efficiency of 

the subsistence whaling harvest. The monitoring program demonstrated the robust size and 

health of the bowhead whale population (Figure 3-71) and has resulted in an increase in quotas 

and in the number animals harvested each year (Figure 3-72). It has also created an incentive for 

the reduction of “struck and lost” whales that has been quite successful. Currently AEWC comanages the Alaskan subsistence bowhead whale hunt with the United States Government, and 

this management regime is consistently cited as one of the most successful examples of such 

management. 

Figure 3-71. Estimated population size of the Bering-Chukchi-Beaufort Sea stock of bowhead 

whales between 1978 and the present. From Gakginaitis et al. (2009). 

Bering-Chukchi-Beaufort Seas Bowhead Whale 

Population by Year, 1978-Present

R2 = 0.853

R2

 = 0.8563

0

2000

4000

6000

8000

10000

12000

14000

1975 1980 1985 1990 1995 2000 2005 2010

Year

Bowhead Populatio

n

Population

Linear (Population)

Poly. (Population)
200 

Figure 3-72. Number of bowhead whales struck in the annual subsistence hunt by year and 

country. Whales landed and struck and lost are indicated. From Galginaitis et al. 

(2009). 

The AEWC Management Plan for the subsistence bowhead whale hunt provides definitions, 

rules or guidelines of conduct, and management mechanisms for subsistence whaling. It states 

that all subsistence whaling must be conducted in “the traditional harvesting manner,” meaning 

that only “traditional” weapons may be used. The first strike on a bowhead whale must be made 

with a harpoon or a darting gun with line and float attached, which also fires an explosive 

projectile (or “bomb”) into the whale at the same time. A fuse that is lit by a percussion hammer 

mechanism when the bomb first hits the whales is timed so that the bomb explodes only after it 

has penetrated the whale. A shoulder gun may be used to fire additional bombs into the whale 

(without additional harpoons and floats) only after a line has been secured to a whale, or when 

pursuing a wounded whale with a float already attached to it. A lance may be used after a line 

has been secured to the whale (AEWC 1995:7). 

The AEWC Management Plan defines a “whaling crew” as “...those persons who participate 

directly in the harvest or attempted harvest of the bowhead whale and are under the supervision 

of a captain” (AEWC 1995). This will be distinguished in this report from “boat crew,” since it is 

not uncommon for Nuiqsut whaling crews to consist of several boat crews, all under the 

supervision of a single captain. Further, some whaling crew members never go out in the boat, 

but provide other important services (help in butchering, provision and maintenance of 

equipment, logistical support or other services such as cooking). “Boat crew” is thus a subset or a 

part of a larger whaling crew. A typical Nuiqsut boat crew consists of three or four crew 

members in an aluminum or fiberglass boat. The usual position for the harpooner is at the front 

of the boat where the darting gun and holder are located. The harpoon line is always rigged on 

the right side of the boat. 

0

20

40

60

80

100

19731975197719791981198319851987198919911993199519971999200120032005

Year

Bowhead Whales

Alaska, USA (landed) Western Canada (landed)

Siberia, Russia (landed) Alaska, USA (struck & lost)

111
201 

For this report, “whaling crew” refers to all those persons on Cross Island directly under the 

supervision of a whaling captain. “Boat crew” will refer to those persons who actually go out in a 

given boat on a given day, and will generally be a subset of a whaling crew, even for those 

whaling crews with only one boat. In recent years most Nuiqsut whaling crews have used more 

than one boat, although this was evidently not as common in the past when more whaling 

captains (and whaling crews) were active. 

3.7.4 81BThe Historic Context of Cross Island Whaling 

The present community of Nuiqsut has a relatively short history, having been resettled in 1973. 

However, Inupiat use and occupation of the Nuiqsut area has a very long history, which is the 

basis for Nuiqsut’s status as a village recognized under the Alaska Native Claims Settlement Act 

(ANCSA). Nuiqsut is located about 12 miles inland on the west bank of Nickalik Channel, the 

westernmost distributory of the Colville River (Figures 3-70 and 3-73), which is not a typical 

location for a whaling community. However, its residents trace their ancestry to people who 

whaled in the mid-Beaufort Sea (including near Cross Island) in the first half of the twentieth 

century, as well as prior to that time. 

Figure 3-73. Map showing the location of Nuiqsut and Cross Island, the routes taken by whalers 

to move to and from the island and a GPS tracks map for whale hunts performed each 

fall between 2001 and 2007. From Galginaitis et al. (2009). 
202 

Figure 3-71 shows the location of Nuiqsut on the Colville River and Cross Island in the Beaufort 

Sea. It also shows typical routes between Nuiqsut and Cross Island, some significant landmarks 

in-between, and GPS tracks for all documented whaling trips (“scouting” for whales) for 2001-

2007. This indicates how far from Nuiqsut whalers must travel in order to set up their whaling 

camps, and also the year-to-year variability in how far they must go from Cross Island to find 

and land whales. Describing and explaining this variability is the primary focus of the body of 

this report. The community of Nuiqsut was built recently, with a regular rectangular grid of 

streets and modern facilities, located on a river channel. The structures on Cross Island are 

contemporaneous with those of Nuiqsut, but are typical of those at hunting or fishing camps. 

Cross Island is about 117 km northeast of Nuiqsut “as the crow flies” and from 148 to 163 km 

away by boat, depending on which channel of the Colville River can be used to reach the ocean. 

The shorter, more protected route is passable during periods of high river water level. The 

roughest part of the trip tends to be the passage through deeper and potentially rougher water 

from West Dock to Cross Island. Cross Island is about 18 km offshore but, more important from 

a logistic point, it is about 16 km from the Endicott causeway and 24 km from West Dock. 

Endicott is about 23 km east of West Dock, adding significantly to any trip between Nuiqsut and 

Cross Island in adverse conditions Figure 3-73. 

Prehistoric use of Cross Island has not been well documented or investigated archaeologically, 

but several families used the island seasonally as a whale hunting base during the first half of the 

twentieth century. Taaqpak hunters used Cross Island as a whaling base from the early twentieth 

century through the late 1940s. Many current Nuiqsut whalers learned from Taaqpak’s 

crewmembers (or those who had learned from such people). Taaqpak maintained that Inupiat had 

hunted whales near Cross Island for centuries, supporting the cultural continuity of Cross Island 

whaling. 

Cross Island is now a low sandy barrier island with an artificial higher area built from gravel. 

When the Nuiqsut whalers started to use Cross Island as a logistical base in the 1980s, there were 

areas of tundra and vegetation, and the remains of old sod houses, on the island. The tundra and 

any obvious signs of past habitation have since disappeared. The higher area was constructed for 

earlier oil and gas exploratory drilling. Cross Island is about 4.8 km long and 137 m wide, and is 

constantly changing due to erosion and redeposition. Logistical support for whaling on Cross 

Island was very difficult, especially in the earlier years. The oil and gas industry (and especially 

BPXA since the development of the Northstar production facility and Shell since they have 

ramped up their exploration program nearby in Camden Bay) has been providing a variety of 

logistical support to Nuiqsut whalers as a mitigation measure for potentially disrupting 

subsistence whaling by seismic, exploration and development activities. 

Approximately 55 bowhead whales were harvested by Nuiqsut whaling crews from Cross Island 

between 1973 and 2007 (Table 3-52). Incomplete records indicate that eight whales were 

harvested by whaling crews from Cross Island between 1921 and 1940. Poor success in the early 

years was attributed to poor weather and ice conditions in some years and to the difficult 

logistics conditions. Later difficulties were attributed in some cases to interference by oil 

industry operations as well as weather conditions. Weather and ice factors are also evident in the 

three years with the greatest incidence of “struck and lost” whales (1989- 1991 or 1992). 
203 

Table 3-52. Documented harvest and struck & lost bowhead whales near Cross Island between 

1973 and 2007. Years with no documented landed or struck& lost whales are not 

included. From Galginaitis et al. (2009). 

Year 

Whales 

Quota Landed Struck & Lost Notes 

1973 NA 1 0 

1982 1 1 0 

1986 2 1 0 

1987 2 1 0 

1989 3 2 2 Oil industry vessel disturbance noted 

1990 3 0 1 Oil industry disturbance, also rough seas 

1991 3 1 2 Poor weather, bad ice conditions 

1992 3 2 1 

1993 3 3 0 Very favorable conditions 

1995 4 4 0 

1996 4 2 0 

1997 4 3 1 

1998 4 4 1 

1999 4 3 0 

2000 4 4 0 Very favorable conditions 

2001 4 3 0 Little ice, whales relatively distant and skittish 

2002 4 4 1 Little ice, whales closer than in 2001 

2003 4 4 0 Poor weather, whales close to Cross Island 

2004 4 3 0 Poor weather, whales close to Cross Island 

2005 4 1 0 Very poor weather, bad ice conditions, disruption 

2006 4 4 0 Ice restrictions first half of season 

2007 4 3 1 No ice, generally poor weather and rough sea 

conditions, whales close to Cross Island 

Once Cross Island was established as a logistical center for Nuiqsut whaling, and current Nuiqsut 

whalers gained experience there, harvest success became much more regular – although other 

factors contributing to that success are more moderate ice conditions since 1992 and the 

logistical support provided through the Conflict Avoidance Agreement (CAA) between the 

whalers and industry. With the development of Northstar, a new CAA for the Beaufort Sea was 

negotiated and signed each year. The CAA process has been incorporated into the Incidental 

Harassment Authorization (IHA) and Letter of Authorization (LOA) permitting processes 

administered by the National Marine Fisheries Service and the Fish and Wildlife Service when 

proposed industry activities may have potential effects on the subsistence use of marine 

mammals. 

At the most basic level, the CAA provides for the constant communication between industry and 

the whalers about all of their respective ongoing activities, so that each can avoid interfering with 

the other. The mechanism for this mutual communication is the Whaling Communication Center 

(WCC – also referred to as the Conflict Avoidance Communication Center or the Oil/Whalers 

Communications Center) in Deadhorse. The Deadhorse WCC operates during each fall whaling 

season and is staffed by bilingual radio operators, usually with at least one from Nuiqsut and one 
204 

from Kaktovik. All industry and whaling vessels are required to report their activities to the 

WCC in real time (purpose, time left, time returned, significant events as they occur), and the 

WCC maintains a log of these reports which is archived by the AEWC. This provides a record of 

activities as they take place, and also documents to some extent the whaling activities. It also 

allows the WCC to advise industry of planned industry activities that may interfere with ongoing 

whaling, or to suggest windows of opportunity (when whaling is not taking place) when industry 

activity may have minimal potential effects. Unfortunately, vessel activity not associated with 

the oil and gas industry (for example, commercial barge traffic) need not coordinate with the 

WCC in the same way, so that this is not a totally effective mechanism for mitigation. 

Other sorts of logistical support have been supplied at least in part by industry. These have 

included low-cost connex units (converted into seasonal cabins on Cross Island); a winch to help 

haul whales up at Cross Island; assistance with a steadier supply of gasoline; a generator system 

to supply electricity to the cabins during the whaling season; diesel fuel (for the winch and 

generator); water, and other supplies; help with transporting the butchered whale to Nuiqsut; at 

least limited phone service for one or two whaling crews; help with mobilization and 

demobilization; and the assurance of available emergency assistance. Alaska Clean Seas (ACS) 

or a contractor with similar capabilities is the industry’s contractor for much of this OWA 

support, as a small part of its overall responsibilities (which are mainly logistical and/or related 

to oil spill response). BPXA, Shell, and ConocoPhillips provided most of the funding for 

implementing the CAA, but BPXA and more recently Shell bear the majority of CAA-related 

costs since ConocoPhillips has relatively few offshore interests in the Beaufort Sea. The AEWC 

does pay for some of the services provided under the CAA, but the amount and exact services are 

not reported. Neither industry nor the whalers disclose the financial terms of the CAA. In recent 

years some industry proposals for exploratory and development activities have created some 

tensions that have complicated the negotiations for the annual CAA, with some oil and gas 

companies indicating that they may not wish to participate in or support the CAA process in the 

future. 

Preparations for whaling, in one form or another, take place during the entire year. This report 

focuses only on the actual harvest activities at and near Cross island during the fall whaling 

season, and does not describe or discuss in much detail the extensive support activities and 

celebratory and distribution events that take place throughout other parts of the year. During the 

period discussed by this report, 2001-2007, a minimum of three whaling crews, and a maximum 

of five, whaled from Cross Island in any one season, with an average and a median of four 

whaling crews per season. Seven different whaling crews were active for at least one season 

during this period. Only one whaling crew was active during all seven seasons. The final 

preparation of boats and equipment for whaling happens in Nuiqsut in August, and a meeting of 

the NWCA in late-July to late-August is usually conducted to set a date for the start of the 

hunting effort and to review the rules and regulations. Labor Day, the first Monday in 

September, is the normative date for all whaling crews to go to Cross Island, but whalers say it is 

not unusual for individual whaling crews to go out earlier, especially if Labor Day is “late.” 

Whalers also state that normatively all whaling crews would go out to (and come back from) 

Cross Island together, on the same day. For the 2001-2007 seasons, as discussed below, patterns 

were clearly different, although Labor Day is a significant time marker for the start of whaling. 

Most whaling crews did leave Cross Island to return to Nuiqsut on the same day, but did not 
205 

necessarily travel together. For two seasons, one whaling crew stayed on Cross Island one day 

longer than the others. 

Usually, one day is spent in transit to and from Cross Island, unless a boat encounters mechanical 

or other difficulties. Once on Cross Island, the focus is on whaling, with little effort devoted to 

other subsistence activities. There were a few instances of seal harvest, the taking of nuisance 

polar bears, and incidental bird hunting. None of these other subsistence activities took place 

every season, and only polar bear were perceived as a “likely” other harvest to occur. This was 

clearly due to the fact that polar bears are attracted to Cross Island by the whales that the whalers 

butcher. The bears represent both a nuisance and potential hazard as well as a possible 

opportunity for harvest, if a hunter wants to take a bear. Most of Nuiqsut’s polar bear harvest 

takes place at Cross Island during whaling, but the understanding is that a hunter needs his 

whaling captain’s permission to kill a polar bear and, if he does so, the captain has the right to 

claim the skin. This effectively limits the take of polar bears to those commonly perceived as 

nuisance/hazardous bears. If a whaling crew member can make a case for how he will use a bear, 

and that it will not detract from his whaling effort, permission may be given to kill a nonnuisance bear, but there were few instances of this during 2001-2007. 

Nuiqsut whalers usually will go scouting for whales on any day when the weather is suitable for 

finding and striking whales, unless a whale was taken the prior day, in which case butchering 

usually has priority. However, this pattern may be changing. In 2003, whalers landed three 

whales in two days (September 5 and September 6) to complete their quota during a rare period 

of good whaling conditions (Galginaitis and Funk, 2005). In 2004, they landed two of their 

whales on successive days (September 5 and 6), again to take advantage of good conditions 

(2006). In 2006, Nuiqsut whaling crews landed single whales on three successive days, 

apparently because the whales were relatively small and the whalers wanted to take advantage of 

a period of good weather for scouting (Galginaitis, 2007). In 2007, they purposely landed two 

whales on one day in order to complete their quota and close their season due to the uncertainty 

of future conditions for whaling (Galginaitis, 2009). 

Whalers invariably use the term “scouting” rather than “hunting” to describe looking for whales 

to strike. Good whaling weather is determined more by wind speed and sea conditions than 

anything else. Whalers prefer days with no wind, but winds up to 8 to 16 km/h (5-10 mph), or 

even higher, can be acceptable. Sea conditions generally correspond with wind speed, but 

scouting can occur even with higher winds, depending on the circumstances. Ice cover, 

especially when the ice edge is not too far from shore but also to some extent floating ice floes, 

generally moderates the effect of wind by dampening wave height. During the period of this 

report, 2001-2007, the ice edge has always been quite distant from shore, and significant ice 

floes have been mostly absent. There were some large ice floes present in 2001 (Galginaitis and 

Funk, 2003a), fewer in 2002 (Galginaitis and Funk, 2003b, 2004), and almost none of 

significance since then. In 2005 and 2006, localized consolidated pack ice along the north shore 

of Cross Island limited the area where Nuiqsut whalers could hunt for whales (Galginaitis, 2007, 

2008). 

Boats typically scout for whales with a complement of three or four people, although since 2001 

boat crews ranged in size from two to seven (average 3.9). Although solitary boats do take 

whales on occasion (for example the first two strikes by Nuiqsut whalers in 2007 were conducted 

by boats scouting alone), it is not encouraged. Nuiqsut boats almost always scout for whales 
206 

with at least one other boat, in case of mechanical break down or other emergencies. Whaling 

crews with two or three boats are willing to whale without the support of other whaling crews, 

and this is one reason for a single whaling crew to use more than one whaling boat. It is still 

commonly agreed that five to seven boats is a preferable number to have available for scouting 

whales on a given day, and this was generally the case once three of four whaling crews were at 

Cross Island. The availability of fewer boats decreases the efficiency, safety, and overall chance 

for success of the hunt. For 2001-2007 the average number of boats out scouting for whales was 

actually 4.2, reflecting periods when only one or two whaling crews were at Cross Island, 

mechanical problems, or other particular circumstances. 

Once Nuiqsut whalers spot a whale and determine that it is a proper whale to take (generally 7.6 

to 10.7 m [25 to 35 ft] long, and not a mother with a calf), they will approach it at high speed so 

that it dives. They will then estimate where it will reappear (usually in 5 to 10 min, but 

sometimes longer) and once they reach that area will wait and search at low speed until the 

whale surfaces and is spotted. They will then repeat the process. The objective is to tire the 

whale so that it must stay on the surface for longer periods of time, until one of the boats can get 

close enough to strike the whale on its left side with the darting gun. The whale is killed by the 

delivery of whale “bombs”, which are in essence very large bullets with timed fuses (generally 4 

to 8 s) that explode inside the whale. Inupiat whalers adopted this technology from the 

commercial Yankee whalers. The whale bombs are delivered to the whale via two methods: a 

darting gun attached to a harpoon, or a shoulder gun. 

During fall whaling, the first bomb is delivered via a darting gun, which at the same time deploys 

a harpoon with an attached float. The harpoon and darting gun are both attached to a long 

wooden handle. This is thrown from the boat at the whale, usually at a distance of no greater 

than 3 or 4.6 m (10 or 15 ft), and ideally closer. Once the whale is struck, the harpoon separates 

from the handle. A trigger rod fires the darting gun and shoots the bomb into the whale. An 

internal hammer ignites the bomb’s fuse once it hits and penetrates the whale’s skin and the 

bomb explodes 4 to 8 s later (depending on how long a fuse was used). The darting gun remains 

on the handle and thus floats in the water until it can be recovered. It must be dried and cleaned 

before being used again. In extreme cases, this can be done on the water, but is usually done on 

shore. Thus, most darting guns are effectively one-shot weapons. Each whaling boat has at least 

one, and sometimes two, darting guns on board. The second weapon used to deliver whale 

bombs is the shoulder gun—a very heavy, short barreled, high caliber “rifle” used to shoot the 

same sort of black-powder bomb as is used in the darting gun, only with fletches or fins to help 

stabilize its flight in the air. In the fall, the shoulder gun can only be used after a float has been 

attached to a whale with a darting gun. The first bomb kills some whales. However, when 

multiple bombs are required, the shoulder gun is useful because it can be used to fire more than 

one shot. 

Until recently, all Nuiqsut whalers used the “traditional” black powder bombs – technology 

adopted from the commercial Yankee whalers. All captains, or a trusted member of a captain’s 

whaling crew, loaded and assembled these bombs each year, often only after reaching Cross 

Island, due to the hazards involved. As discussed above, the darting gun and shoulder gun black 

powder projectiles are essentially the same. The more recently developed “super bomb” can only 

be used on a darting gun, with a specially modified barrel. It is manufactured in Norway, uses 

penthrite instead of black powder, and is designed to kill whales faster than a black powder 
207 

bomb. It is a product in the interest of developing more efficient weapons for subsistence 

whaling, but development has been somewhat delayed due to the relatively small demand and its 

somewhat complicated operation compared to the black powder bomb (Øen 1995; Sadler and 

Grønvik, 2003; AEWC 2006). 

The darting gun is always thrown from the right side of the boat, since it is attached to a line and 

the float, and this line is always rigged on the right side of the boat. If the darting gun were 

thrown to the left of the boat, the float line would then stream across the boat at high speed, 

endangering the boat crew and the structural integrity of the boat. Thus the whale is usually 

approached and struck on the whale’s left side, since the boat normally “catches up” to the whale 

from behind it in order to achieve a striking position. Nuiqsut whalers report that whales are 

sometimes approached and struck from the front, but that this is unusual and has not been 

documented for this research. 

When a whale is taken, it is towed to Cross Island, usually by all the boats that had participated 

in the chase. Depending on the size of the whale, the distance back to Cross Island, weather 

conditions and sea-state, and how many whales had already been landed that season, boats that 

had not gone scouting that day may be called in help with the tow or boats that had participated 

in the hunt may be given the option of trying to strike a second whale on the same day. Once at 

Cross Island, the whale is hauled up on the gravel beach using a loader that is on Cross Island for 

the duration of the whaling season and/or a diesel-powered winch, and butchered. 

The first cuts into the whale are made by the captain of the whaling crew that landed it (or his 

designated representative) and are used to delineate the tavsi, or captain’s belt (share). This belt 

can vary in width from perhaps 12 to 18 inches, and some captains will designate two such belts 

on large whales. The back boundary of the tavsi is usually the “bellybutton” of the whale with 

the other edge forward of that, although some captains may adjust this based on the size and 

body configuration of the whale landed. The tavsi essentially divides the whale into two parts, 

the uati (forward of the tavsi, composed of the upper torso of the whale) and the ningiq

(backward from the bellybutton of the whale to the tail). The ningiq is used for whaling crew 

shares and is divided equally among the whaling crews that helped land and butcher the whale. 

The uati is reserved for sharing with the community at large, primarily at celebratory feasts 

(Thanksgiving, Christmas, and Nalukataq). The tongue is divided equally between uati and 

ningiq. Half of the baleen belongs to the captain of the whaling crew that landed the whale, and 

the other half is divided among the whaling crews (generally including the whaling crew that 

landed the whale) that helped to tow the whale to Cross Island. One flipper belongs to the 

harpooner who first struck the whale, and the other flipper is available to be shared by any and 

all whaling crew members of all crews. In practice, since Cross Island is fairly remote from 

Nuiqsut, most whaling crew members do not take portions of this flipper and it is generally 

processed as part of the uati after it has been available to all crew members for several days. 

Usually all whaling crews will help with the primary butchering of the whale – taking off all the 

usable parts and dividing them into tavsi, uati, and ningiq. The whaling crew that landed the 

whale is then responsible for the further processing of the uati so that it can be packed and 

transported to Nuiqsut. All other whaling crews, other than the one that landed the whale, are 

responsible for processing the ningiq into smaller portions that can then be divided equally 

among the whaling crews helping with landing and butchering the whale. The first whale is a 

special case, in that the ningiq is divided equally among all the crews that whale at Cross Island 
208 

that season, even if they were not on Cross Island when the first whale was landed and did not 

assist in the hunt or butchering of that whale. 

Select parts of the whale from the tavsi (captain’s belt) are sent to Nuiqsut via whaling boat the 

same or the next day “to feed the village.” The rest of the meat, muktuk, organs, and baleen is 

packed into containers (either plastic fish totes or more recently heavy cardboard boxes) and 

transported to West Dock and then to Nuiqsut (most recently via ACS barge and air freight). 

What is left of the whale is taken to the bone yard. Once the quota is taken or conditions threaten 

to prevent boats returning to Nuiqsut (formation of ice), the whalers clean up the island, pack, 

and leave. Most will leave for Nuiqsut on the same day. Captains who have taken whales that 

season will fly their flags. Whaling will generally be completed by mid- to late-September (an 

apparent change from the past, discussed below). In Nuiqsut, each whaling crew will process 

their total crew shares into smaller portions, divide each sort of item (several types of muktuk, 

meat, etc.) into the number of equal individual crew shares determined by the captain, and 

apportion a share to each crew member or other individual. Each whaling crew that landed a 

whale will store its uati in the captain’s ice cellar. 

Nuiqsut whalers first used wood boats and relatively small motors. Although they remember 

these vessels with fondness, and long for the economy of those motors, they also remember that 

they were limited in terms of speed and towing capability. Currently Nuiqsut whalers all use 

aluminum or fiberglass boats, 18 to 24 feet long, with motors of 80 to 225 horsepower. It is 

possible that a 16-foot boat may be used as a whale boat on occasion, but it would not be 

considered a primary boat. A few boats have cabins, but most are open. Boats typically scout for 

whales with a complement of three or four people, although some boat crews are as small as two 

and as large as eight. 

In the recent past, Nuiqsut had as many as eleven active whaling captains. Currently, the number 

is smaller than that. Some captains who do not expect to go whaling do not register with the 

AEWC each year, and others have retired. When eight or more whaling crews went out whaling 

there was little reason for captains to run multiple whaling boats. When relatively few (three or 

four) captains go whaling, the number of boats available to assist in chasing and towing the 

whale are too limited unless some whaling crews use more than one whaling boat. Also, the only 

way that a whaler who is not registered as a whaling captain can take his boat out whaling is as a 

boat (usually a second or third boat) for a registered captain. This is one way that people with the 

goal of becoming whaling captains acquire the experience to support their eventual application to 

their local WCA and the AEWC to become a registered whaling captain. Thus, part of the reason 

that most whaling crews (63 percent) during the study period used more than one whaling boat 

was probably due to the fact that only three to five whaling crews were active during any given 

season.. Whaling crews with two or three boats are willing to whale on their own, but it is 

commonly agreed that five to seven boats is a preferable number to have available for whaling 

on a given day. More boats would be useful, and the availability of fewer boats decreases the 

efficiency, safety, and overall chance for success of the hunt. 

3.7.5 82BTrends in Nuiqsut Bowhead Whale Harvest 

Table 3-52 summarizes the strikes for Nuiqsut whalers since 1973 (the date the community was 

resettled). The first whale landed by residents of the current community of Nuiqsut was struck 

near the Flaxman Island/Canning River area, well east of Prudhoe Bay and Cross Island. 
209 

Whaling continued in subsequent years, but success from 1973 until at least the mid-1980s was 

intermittent, with the next whale landed in 1982 and the one after that in 1986. Starting in 1986, 

whales were landed on a more regular basis and Nuiqsut whalers first used their full quota of 

strikes (plus a “transferred” strike) in 1989. They first landed their full quota of whales in 1993 

and have done so on a regular basis since then. For the period 1973-1992, they landed 9 whales 

and had 6 struck and lost, for a landed percentage of 60 percent. A quota was only established in 

1978, so a comparison with possible harvest is not possible. For the period 1978-1992 (fully 

covered by a quota assigned to Nuiqsut), Nuiqsut whalers landed 8 whales, struck and lost 6 (a 

landed percentage of 57 percent) and had a quota of 25 strikes over the period. They used only 

56 percent of the strikes and landed only 32 percent of their quota. For the period 1993-2007, 

Nuiqsut whalers had an aggregate quota of 55 whales and landed 45 (82 percent of their quota) 

and had only 4 struck and lost whales (a landed percentage of 92 percent of the strikes used). 

Nuiqsut whalers used 49 strikes during this period (89 percent of their quota). This demonstrates 

a clear improvement in efficiency, both in terms of an increased percentage of landed whales 

versus struck and lost whales, as well as in terms of more fully using their quota and satisfying 

the community’s need. Most Nuiqsut whalers indicate that four whales, each about 25 to 35 feet 

in length, provide enough meat and muktuk for everyone in the community, with enough left 

over to share with people in other villages. Three whales, if they are larger than 35 feet, can be 

enough and in some years Nuiqsut whalers have foregone landing a fourth whale for this reason. 

Whalers report that, during the fall migration, the smaller whales reach Cross Island before the 

larger ones, and that they have a preference to land smaller whales (35 feet or less). This 

preference is consistent with the AEWC management guideline for whalers to strike only 

sexually immature animals (generally less than 38 feet). There has been a trend, not statistically 

significant, for size of whales landed to decline between the 1980s and 2007 (Figure 3-74). The 

trend may be skewed because most of the whales taken in the 1980s and early 1990s were landed 

in late September or October, when larger animals may have composed more of the animals 

present than in early- to mid-September, when Nuiqsut whalers currently whale. Current whalers 

may have more of a preference for smaller whales than did whalers in the past (some whalers 

state it the other way – that past whalers may have had more of a preference for larger whales). 

Another factor is that current whalers use larger boats with more powerful motors, and have 

more reliable gas supplies and logistical support, than whalers in the 1980s and early 1990s. 

While they are not able to wait for long periods of time for a “preferred” whale, they can at times 

decide not to chase a whale that is “too big” early in the season, with the expectation that they 

will have other opportunities later in the season. Nuiqsut whalers in the 1980s and early 1990s 

did not have the same degree of freedom and tended to chase and strike whatever whale made 

itself available. 

Smaller whales seem to be more likely to be landed earlier in the season than are larger whales – 

but the same skewing effect of current whalers hunting earlier in September than did past 

whalers may apply (Figure 3-75). There is little question that whalers are whaling, and landing 

whales, earlier than in the past. Whalers say that, in the past, it was common to hunt caribou on 

the way to Cross Island, or to make trips to the mainland from Cross Island to hunt caribou, to 

support themselves while whaling. They also say that whaling crews often took fish nets to Cross 

Island, and would hunt seals for food. The captain who landed the first whale for Nuiqsut in 
210 

Figure 3-74. Historic trend in length in feet of bowhead whales landed by Nuiqsut whalers from 

Cross Island between 1982 and 2007. From Galginaitis et al. (2009). 

Figure 3-75. Historic trend in date of bowhead whale landings by whalers from Cross Island 

between 1982 and 2007. From Galginaitis et al. (2009). 
211 

1973 often told the story of how, after two weeks, he and his crew had run out of food except for 

some salt and tea, and how they lived for weeks on nothing but seal. In those days they not only 

hunted for food to support their whaling activities, but also for gas. Because of past military and 

industry activities, drums of various materials were left at numerous locations all along the coast, 

and Nuiqsut whalers made use of the fuel that they could find. They were very limited in what 

they could bring from Nuiqsut, and could not always rely on being able to buy what they needed. 

What they did have more of in the past than they do currently is time. In many ways, increased 

access to economic resources and improved technology is used to decrease the time required to 

successfully harvest subsistence resources, in this case bowhead whales. Nuiqsut whaling 

captains commonly remark that it is very expensive to be a whaling captain, and that to field a 

whaling crew on a regular basis one needs a good job or a wide and strong support network, or 

preferably both. 

3.7.6 83BMethods 

Three main types of information were collected in this project: systematic GPS observations of 

whale hunts, systematic observations of various components of subsistence whaling activity; and 

whalers’ observations on whale behavior (and especially changes in such behavior). This last sort 

of information is often accompanied by perceptions of possible causes for such changes and the 

implications such changes may have for subsistence whaling activities. 

The objective of this work was to determine if subsistence whaling activity and behaviors in the 

vicinity of Cross Island are significantly adversely changed by offshore oil developments at 

Northstar and/or Liberty and if general subsistence activities on/near Cross Island are 

significantly adversely changed by oil and gas activities associated with Northstar and/or 

Liberty. The MMS Cross Island project was intended to describe Cross Island whaling using 

measures that document year-to-year variability in whaling and, when sufficient time series data 

are available, will allow tests of hypotheses on the causes of this variability. Concern about 

potential effects of oil and gas development on whaling is the prime motivation for the MMS 

project, but it is recognized that other factors can strongly affect Cross Island whaling and thus 

need to be considered as well. These other factors include weather and ice conditions, 

equipment problems, whalers’ decisions, and non-industrial human activities. During the MMSsponsored project, information was collected on level of hunting effort, including how many 

boats go out each day, boat crew size, how much time is spent on the water, lengths of trips in 

miles, and furthest point away from Cross Island during each trip. Information is also collected 

on the abundance and distribution of whales, including the number and location of whales 

observed and/or struck by the whalers. This information will be applied to internal MMS 

management leasing plans and decisions, as well as stipulation requirements, and has also been 

recognized as important for the management decisions for other agencies. 

Information on the level of hunting effort was collected by systematic observations by Dr. 

Galginaitis, who was on Cross Island for most of the whaling season in each of 2001–2007. This 

information was supplemented by conversations with all of the boat crews. Further information 

on the hunting effort, and on the abundance and distribution of whales, was obtained by issuing 

Garmin handheld GPS (Global Positioning System) units on all boats. The whalers were given 

instructions on how to record the GPS coordinates (track) of the boat’s trip, and how to mark 

waypoints of significance, including whale sightings and strikes, sightings of vessels other than 

whaling vessels, and other pertinent observations. This information was then mapped. Whalers 
212 

tended to mark relatively few points when on the water, and the points they do mark represent 

the boat’s position at the time a whale or group of whales was seen. These whales may be quite 

close or miles away. 

This information was supplemented by subsequent conversations with each boat crew, while 

reviewing the mapped GPS information on a laptop computer with them. When reviewing tracks 

after their return, boat crew members would often identify locations where they saw whales, and 

these points were added to the GPS information. Some of these points were boat positions, and 

some were estimated positions of whales (and thus not on a boat track). Other points were 

reference coordinates and may represent past whale sightings, so they also may not be on boat 

tracks. Galginaitis did not accompany the whalers in their boats while they were hunting, since it 

is not permissible for any non-native to participate actively in hunting marine mammals. 

What has become clear from an examination of the seven field seasons of data is that, at least 

during the period of study, there does not appear to be any clear way to demonstrate any adverse 

effects of oil and gas activities on Cross Island subsistence whaling. There are several possible 

components to this result. First is the existence of the CAA between the whalers and industry. 

The CAA, for the most part, has minimized adverse effects of industry activities on whaling 

activities and vice versa. The CAA has had a positive effect in its logistical support provided to 

the Cross Island whalers. This does not mean that there is no disagreement between industry and 

the whalers, or that specific conflict incidents did not occur during the period of the research. 

Such incidents were singular in nature, however, and not amenable to generalization or statistical 

treatment. Second, obtaining detailed information on the timing and geospatial location of oil 

and gas activities was not part of this project and has not been systematically compiled by 

BOEMRE/MMS or others. The MMS Human Activities Database documents only the period 

before 2000, and not in great detail. Thus, it is difficult to articulate possible mechanisms of 

articulation between oil and gas activities and subsistence whaling. Third, oil and gas activities 

are only a subset of commercial activities that can potentially affect subsistence whaling. 

Commercial barge and other vessel traffic is a great concern to subsistence whalers, and the one 

major incident that occurred during the period of the research involved an encounter between 

whaling vessels and a commercial (non-oil and gas) tug and barge in 2005. At present, there are 

few if any reporting requirements for such commercial (or non-commercial) vessel traffic. 

Fourth, many subsistence whalers are most concerned about the potential effects of events or 

activities that have not yet taken place, such as offshore oil spills, or offshore development to the 

east (rather than the west) of Cross Island, for example. The data collected on the 2001-2007 

whaling seasons cannot address concerns about future hypothetical impacts, other than to 

provide comparative information that may be useful to gauge or measure future effects. 

It is clear that Cross Island subsistence whaling is quite variable, and that the seven years of data 

are quite useful in describing this variability. Factors that seem to account for most of this 

variability are the weather (especially wind speed), ice conditions, the decision-making 

characteristics of individual whaling captains, and other activities going on in the vicinity of 

Cross Island. As discussed above, the last factor was either largely absent, or to the degree 

present largely undocumented, and so is not explicitly treated at any great length in this report. 

To the extent that these activities do take place and are documented, the variability of Cross 

Island whaling documented here may be attributable to them to some degree. 
213 

3.7.7 84BResults 

Results are discussed in this section in terms of the quantitative observations designed as 

measures of subsistence whaling activity and the less quantifiable observations and perceptions 

of Nuiqsut whalers about whale behavior in the 2001-2007 Cross Island whaling seasons. The 

primary focus is on year-to-year comparisons and the discussion of variability. 

3.7.7.1 129BQuantitative Measures 

Detailed quantitative data will not be presented here. Rather, the following discussions are based 

on the summary and comparison of these data presented in Table 3-53. Some of the discussions 

will reformulate portions of these data, or present supplemental details. Quantitative measures 

that are considered significant are included in Table 3-53. When composing discussions of 

various aspects of the 2001-2007 Cross Island whaling seasons, it became clear that other 

available measures were also pertinent to the discussion. Most if not all of the data for 2001-

2007 was developed for this project, but of course most of the data for seasons prior to 2001 

comes from other sources (although they were perhaps obtained or processed as part of this 

project). 

All of the measures discussed in this section relate in some way to the “success” of any given 

season, but “success” is a relative term and may mean different things for different people. In the 

final analysis, Nuiqsut whalers define “success” as landing sufficient whales to satisfy the 

community’s needs (which include a percentage for sharing with residents of other 

communities). Whalers will note seasons with poorer weather more often than others, and 

certainly prefer shorter seasons over long ones, but ultimately judge a season by the number of 

whales landed. Perhaps this is because so many factors that clearly influence the subsistence 

bowhead hunt are beyond the control or influence of the hunters – weather, ice conditions, and 

the timing and path of the bowhead migration, among other possible factors. More anthropogenic 

factors, such as other vessel traffic, oil and gas activities in general, mechanical and equipment 

failures, and accidents, also potentially influence the course of the hunt and possibly “success” in 

landing whales, but can at least in theory be minimized by proper planning and management. 

Whalers seem to differentiate the two categories of factors. Seasons may be characterized as 

“poor weather” years (2003, 2004, 2005, 2007) or “bad ice” years (2005, 2006) or years when 

the whales were farther out or behaving in a different way making the hunt more difficult (2001 

and to some extent 2002). Any of these conditions, or a combination of them, can result in not 

landing sufficient whales for the village – but if 3 or 4 whales are landed, whatever the natural 

conditions have been, the season is considered successful. The one project field season during 

which the whalers experienced direct disruption of their hunt by non-whaling vessel traffic (a 

commercial, but not petroleum industry, tug and barge) was 2005, a “bad ice” and “poor 

weather” season and the only project season when the Nuiqsut whalers landed fewer than 3 

whales (only 1). While a single case is not sufficient to establish an argument one way or the 

other, Nuiqsut whalers characterized this season as much by this disruption incident as by the ice 

and weather conditions. As will be discussed below, absent this incident, they indicated they may 

have been able to land at least one more whale (but would never claim that this was certain, as 

that would not be showing proper respect for the animals). 
214 

Table 3-53. Selected measures of Cross Island subsistence bowhead whaling, 2001 through 2007. From Galgina

Metric Type 2001 2002 2003 2004 2005 2006 

Whales Taken/Whales Stuck&Lost Count 3/0 4/1 4/0 3/0 1/0 4/0 Active Whaling Crews on Cross Island (Max) Count 4 3 4 4 5 4 Active Whaling Crews on Cross Island (Mean/day) Mean 3.8 2.5 2.8 2.6 4.1 4.0 Scouting Boats on Cross Island (Max) Count 7 9 10 8 8 7 Cross Island Population (Max/Ave/day) Mean 35/27.7 39/26.6 33/20.4 33/18.9 43/29.8 38/29.2 Length of Season1 Count 24 23 19 30 27 21 Mean Length of Season/Crews (days on Island) Mean 22.5 19.3 13.2 19.2 21 21 Weather Days Count 8-9 4 8 10 11-15 4 No. Days Scouting2 Count 12 15 7 12 9 10 No. Days Whales Seen3 Count 9 9 7 6 7 8 Boats Scouting/Day Mean 4.8 4.3 4.9 3.4 4.0 4.8 No. Boat Days4 Count 57 65 34 41 35 48 Boat Days/Whale Mean 19 16.2 8.5 13.7 35 12.0 No. Boat Trips (Possible No. GPS Tracks)5 Count 59 67 42 46 48 53 Actual No. GPS Tracks Collected Count 49 52 37 44 48 51 Length of Trip (Miles) Mean 84.0 64.3 37.2 45.3 60.7 60.8 Duration of Trip (Hours:Minutes) Mean 9:43 7:58 4:31 6:51 7:07 8:13 Furthest Point from Cross Island (Miles) Mean 23.6 19.5 11.6 12.1 19.1 22.2 Strike Distance from Cross Island (Miles) Mean 19.5 13.4 9.3 9.7 25.9 17.0 Strike Direction from Cross Island (Degrees) Mean 64° 67° 56° 36° 82° 59° Boat Crew Size Mean 3.9 3.6 2.9 3.6 4.4 4.3 Total Seasonal Boat Effort (Boat-Hours)6 Sum 573 534 163 301 341 427 Boat Hours/Whale Mean 191 133 41 100 341 107 Bout Hours/Strike (Landed + Struck&Lost) Mean 191 107 41 100 341 107 1Number of days with at least on whaling crew on Cross Island, including days of arrival and departure from Cross Island. 2Number of days when at least one whaling boat went out scouting for whales. 3Number of days when at least one whaling crew saw whales while scouting from a boat. Blows were seen from Cross Island on a few non-scouting days, but are not inc4Each boat scouting for whales on any given day counts as one "boat day", regardless of the duration of the trip or if whales were seen or not. 5Some boats made more than one scouting trip on a single day. 6Yearly total equals aggregate sum of duration of all whaling trips by all boats. 
215 

That said, whalers will indicate that some seasons are “better” than others, and generally “better” 

means “shorter” in terms of days spent out at Cross Island (with the caveat that 3 or 4 whales 

were landed). Good weather is preferred, but not a necessary condition, for a “better” season. 

The shortest seasons documented by the project were those with arguably the worst weather 

(2007, 2003) but other factors (whales close to Cross Island and the adaptive behavior of the 

whalers) allowed the whalers to use their full quota of strikes in both years. Thus these finer 

distinctions of what makes some seasons “better” than others – the evaluation of the variability 

between and among seasons - is recognized by Nuiqsut whalers. Thus the measures discussed 

below make sense to the whalers, but some they accept as factors they cannot change but need to 

adapt to (weather, sea conditions, ice conditions, whale migration) and others (anthropogenic) to 

which the whalers mostly (in present conditions) need to adapt. In principle, the anthropogenic 

factors could be (and through “mitigation” or other management practices actually are) 

influenced or minimized, at least in terms of timing or where they take place (oil and gas 

activities, other vessel traffic). The CAA between the whalers and industry is the one mechanism 

for reducing the potential effects of such anthropogenic factors, as are lease stipulations and 

lease deferral areas. It may be the sense that these factors can be limited or controlled that makes 

the cases where they occur, or mitigation measures fail, so salient to the whalers. The following 

discussions focus on specific measures, followed by a more general examination of variability in 

Cross Island whaling. 

3.7.7.2 130BWhales Landed in Relation to Quota 

The most obvious indicator of whaling success is the number of whales taken. The quota for 

Nuiqsut during the project years has been four strikes per season. This usually is expressed as 

“four whales” not because the whalers expect to land four whales or take this for granted, but 

because each strike counts as a dead whale in the bowhead population model, whether it is 

landed or not. This suggests two other measures of degree of whaling success – the number of 

whales landed versus the total number that could have been landed, and the number of whales 

landed versus the number of whales “wasted” or “struck and lost.” Nuiqsut whalers could have 

landed 28 whales for the years 2001-2007. They actually landed 22, or 79 percent. They had two 

struck and lost whales in this period, so they landed 22 of the 24 whales they struck, or 92 

percent. Both represent high rates of success, and probably Kaktovik is the only other Alaskan 

whaling community that may match or surpass them. 

For four of the seasons in the period 2001-2007, Nuiqsut whalers completed their quota of four 

whales – 2002, 2003, 2006, and 2007 (Table 3-53). In both 2003 and 2006 they landed four 

whales, with no struck and lost. In both 2002 and 2007 they had one struck and lost whale, and 

landed three whales in 2007 and four in 2002 (one strike was transferred from the AEWC “bank” 

of unused strikes). The first three whales landed in 2002 were fairly small, so that a fourth one 

was desired to ensure that community needs were satisfied. In 2007 the three whales landed were 

sufficiently large that a fourth whale was perceived as unnecessary and potentially wasteful. It is 

interesting to note that the four years when Nuiqsut whalers completed their quota are also the 

four shortest seasons in terms of number of days for the study period – 13, 19, 21, and 23 days. 

This compares to the “average” season over this period of 22.4 days, and the other three seasons 

of 24, 27, and 30 days. Not coincidentally, the four seasons when the Nuiqsut whalers completed 

their quota are also the four seasons with the fewest weather days – 3, 4, 4, and 8 (although one 

of the other three seasons had “only” 8 weather days as well). 
216 

Although Nuiqsut whalers state that three whales can be sufficient for the needs of the 

community, they clearly have a preference for landing four whales. The longest seasons 

documented by this project are those for which the quota was not completed, whether they were 

seasons when only three whales were landed (2004, 2001) or only one (2005). The median case 

of 2002 is interesting in this regard, as the whalers requested (and received) a fifth strike to use 

to land a fourth whale, as they had struck and lost an earlier whale. As will be discussed in the 

following section, Nuiqsut whalers stay out at Cross Island until they land sufficient whales for 

the village or until the conditions in their judgment become untenable for whaling. 

As a measure of level of effort, the number of whales landed (or strikes used) does not appear to 

be a very useful measure. For all but one of the seasons discussed in this report, Nuiqsut whalers 

landed either three or four whales, and considered the seasons successful. The number of whales 

landed, combined with their size, is a measure of the ultimate success of any given season. The 

AWEC allocates a quota to each Alaskan whaling community based on that community’s needs, 

based on a number of factors (Braund, Stoker, and Kruse,1988; Braund & Associates 1997, 

2007), and fulfilling that quota is each community’s goal for any given season. Nuiqsut whalers 

prefer to target whales 25 to 35 feet in length, but if the first three whales they land are larger 

than this (as in 2007, for example) they may choose to forego trying to land a fourth. In other 

years, Nuiqsut whalers may essentially run out of time before completing their quota, as in 2001, 

2004, and 2005. In 2001 and 2004 they landed three whales, with no struck and lost, and felt that 

at least the basic needs of the community were fulfilled. In 2007, Nuiqsut whalers landed three 

whales and also had a struck and lost whale, but the three landed whales averaged near 40 feet 

each and were judged to more than fulfill the community’s needs. In 2005, only one whale was 

landed due to very adverse weather and ice conditions, and possible disruption from a 

commercial barge, and the whalers were forced to end their season with only this limited harvest. 

The whalers considered 2005 a poor whaling season due to this limited harvest (results of the 

season), attributed by the whalers to the conditions of the season (weather, ice, vessel 

encounters). The whalers distinguish between conditions and results, however. Overall physical 

conditions were good for whaling in 2001 and 2002, but because of the distance of whales from 

Cross Island more effort was expended to land each whale in those years than in other years 

(2003, 2004, 2007) when physical conditions were poorer but whales were more plentiful and 

closer. 

3.7.7.3 13BTiming and Length of Season 

This section will begin with a general discussion of the timing and the length of the 2001-2007 

Cross Island subsistence whaling seasons. It will conclude with a discussion of the effectiveness 

of “length of season” as a measure of level of effort or a characterization of the season as a 

whole. 

As mentioned above, Nuiqsut whalers state that they usually go to Cross Island after Labor Day 

(the first Monday in September) and that ideally, all whaling crews would travel together and on 

the same day. For the seven seasons documented by this project, this was never the case, 

although the 2006 season came very close (Table 3-54). For most seasons (five of seven), the 

first whaling crew left for Cross Island alone. In one season two whaling crews left for Cross 

Island on the same day, and in another season three whaling crews left for Cross Island on the 

same day. In only one case did the first whaling crews actually leave for Cross Island on Labor 

Day. On average, these “first whaling crews” left for Cross Island 6.4 days before Labor Day. 
217 

Table 3-54. Timing and duration of Cross Island subsistence whaling seasons, 2001 through 

2007. From Galginaitis et al. (2009). 

Season 2001 2002 2003 2004 2005 2006 2007 Average 

Date Labor Day (LD) 9/03 9/02 9/01 9/06 9/05 9/04 9/03 9/03 

Date 1st Crews Out (FCO) 9/03 8/30 8/23 8/15 8/30 9/02 8/30 8/28 

FCO-LD1 0 -3 -9 -21 -6 -2 -4 -6.4 

Date 2nd Crews Out (SCO) 9/06 9/01 8/29 8/30 9/04 9/03 8/31 9/02 

SCO-LD1 3 -1 -3 -6 -1 -1 -3 -1.7 

Date 3rd Crews Out (TCO) NA 9/05 8/31 9/04 9/05 NA 9/03 9/03 

TCO-LD1 NA 3 -1 -2 0 NA 0 0 

Length of Season (Days) 24 23 19 302 27 21 13 22.4 

1

A negative number represents the number of days a date occurs before Labor Day. A positive number similarly 

represents the number of days a date occurs after Labor Day. 

2

Not included in this total are an additional 5 days when no one was present on Cross Island. The whaling crew that 

had gone out early returned to Nuiqsut to wait out a period when extremely bad weather was expected. 

One season was clearly anomalous in this regard (one whaling crew leaving for Cross island a 

full 21 days before Labor Day, but only being able to scout for whales five times before Labor 

Day, with no whales seen). Not counting this season, “first whaling crews” still left for Cross 

Island an average of 4 days before Labor Day. In five of the seven seasons whaling crews 

traveled to Cross Island on three different days, and on two different days for the other two 

seasons. On average, the “second whaling crews” left for Cross Island 1.7 days before Labor 

Day, and “third whaling crews” on Labor Day. The behavioral generalization would seem to be 

that whaling crews try to be at Cross Island by Labor Day, with variation due to the individual 

characteristics of the captains making the decision for each whaling crew. Labor Day is an 

accepted date because the temperature tends to be lower in September than in August, which is 

better for maintaining the quality of the butchered products. As the first Monday in September, at 

the start of the week, Labor Day seems to serve as a marker for the start of September – 

explicitly recognized by whalers when they say that they go out to Cross Island before Labor 

Day when Labor Day is “late.” 

Examining whaling crew departure dates for Cross Island strictly in terms of calendar date (and 

not in relation to Labor Day), there is a clear trend for “first whaling crews” to arrive on Cross 

Island in late August (8/28), and for all whaling crews to have arrived by early September (9/03). 

During the seasons documented by the project, Labor Day occurred, on average, on 9/03. This is 

perhaps more support for Labor Day being used as a convenient, already labeled, reference point 

rather than as a definitive one – or perhaps its use as a date that applied to past whaling behavior 

and not as much to current behavior. As will be clear when the data on Nuiqsut whaling since 

1973 are presented below, whaling occurred later in the year before 1993 than it does currently. 

Factors that may help account for such a change will be discussed at that time. 

The whale migration, at least in the past, has also been fairly predictable in terms of timing to 

reach Cross Island on or about September 1, or Labor Day. Some captains are now of the view 

that the bowhead whale migration is starting earlier in the fall than before, and this may simply 

be another way of stating that they know bowhead whales are usually present in the Cross Island 
218 

area in August (precisely when in August is their question). Since the small whales tend to 

migrate first and the whalers prefer the small whales, this is an incentive to some captains to 

leave for Cross Island sometime in August, before Labor Day. Also, although whaling is a 

cooperative endeavor, some captains seek at least a temporary “competitive advantage” by being 

the first whaling crew out at Cross Island (and once on Cross Island, the first whaling crew to 

leave the island to go out scouting for the day). Other factors also influence the decision of when 

a whaling crew leaves for Cross Island – when the boat(s) and crew members are actually ready 

to leave, the other obligations (usually work or meetings of some sort) that the captain and crew 

members may have that may limit the span of time they can stay at Cross Island, and the 

perception that the weather after September 20 has increasingly become more unpredictable and 

poor for whaling. Most Nuiqsut whalers now seem to typically “budget” two weeks for whaling 

at Cross Island, although historically (from whalers’ accounts) most seasons have been longer 

than that. Recent seasons exhibit a number of characteristics that support the conclusion that 

Nuiqsut whalers currently incorporate more time constraints (wage employment, travel and 

meeting obligations) into their whaling decisions than was required in the past (also discussed 

below). 

The relationship between the date whaling crews first go out to Cross Island and the length of the 

season is not clear – except for the obvious that a later start implies a season with fewer possible 

days than does an earlier start. The longest season documented by the project was that with the 

earliest starting date, 8/15 in 2004. This was probably an experiment in response to the 

experience of the 2003 season. In 2003, the first whaling crew arrived on Cross Island on 8/23 

(the second earliest during the project), with other whaling crews arriving 8/29 and 8/31. All 

whaling crews were on hand when the weather broke on 9/01 and conditions were good for 

whaling. The whalers completed the quota on 9/06, and left for Nuiqsut on 9/10 – a season of 19 

days, the second shortest documented by the project. In 2004 a captain may have hoped to 

duplicate this but to avoid the first week of bad weather experienced in 2003 by going out even 

earlier than in 2003. Instead, this whaling crew encountered worse weather than in 2003 and saw 

no whales on the few days they were able to go boating. Once other whaling crews arrived on 

Cross Island (8/29, 9/04) two whales were quickly landed (9/05, 9/06) but conditions again 

deteriorated and even when boats could go out few or no whales were seen. A third whale was 

taken 9/14 and a decision was made to call an end to the season. If the first whaling crew had not 

gone out so early, this would have been a fairly “typical” season in terms of duration and other 

factors. All other seasons were very similar in terms of the date that the first whaling crew(s) left 

for Cross Island, ranging from 8/30 to 9/03. The duration of these seasons ranged from 13 days 

(the shortest documented by the project) to 27 days (the second longest documented by the 

project). Clearly many factors interact and influence the duration of a Cross Island whaling 

season, but the available “window of opportunity” when whales are present, temperatures are 

fairly cool, and weather and ice conditions are acceptable is fairly well delimited as late August 

through middle-to-late September. This is also a change from the documented historical past, as 

some whales were taken by subsistence whalers in the mid-Beaufort in October. 

Table 3-55 summarizes measures related to whale strikes for each season that are consistent with 

and support these conclusions. The first whale of the season was struck during the five seasons 

with no unusual ice conditions no sooner that 8/31 and no later than 9/06. The first whale of the 

season was struck later in 2005 and 2006 because the whalers were prevented from reaching the 

whales by ice conditions that blocked them from boating beyond the barrier islands. As soon as 
219 

they found a way through this ice to the whales in the open water beyond the ice, they were able 

to strike and land a whale (the only whale for 2005, the first of 4 for 2006). Ice conditions in 

2005 and 2006 clearly made these years different from the other five documented by the project. 

The “average strike date” for 2005 and 2006 was September 15, whereas for the other five 

seasons the average strike date was September 8 (and September 10 for all seven seasons). 

Table 3-55. Selected measures related to bowhead whale strikes by Cross Island whalers, 2001 

through 2007. From Galginaitis et al. (2009). 

Season 2001 2002 2003 2004 2005 2006 2007 Average 

Average Distance 19.5 13.4 9.3 9.7 25.9 16.8 12.0 13.9 

Average Bearing 64 67 56 36 82 59 80 62 

Date 1st Strike 5-Sep 5-Sep 1-Sep 5-Sep 14-Sep 13-Sep 31-Aug 6-Sep 

Date Last Strike 22-Sep 15-Sep 6-Sep 14-Sep 14-Sep 18-Sep 7-Sep 14-Sep 

End of Season 26-Sep 21-Sep 10-Sep 18-Sep 25-Sep 22-Sep 11-Sep 19-Sep 

Date Average 

Strike 13-Sep 10-Sep 5-Sep 9-Sep 14-Sep 15-Sep 5-Sep 10-Sep 

Note: “Average Strike Date” (ASD) must be an integer value. For example, the computed ASD for 2001 of 

September 12.333 is a calendar date of September 13. 

The last whale of the season was struck over a wider range of dates, from as early as 9/06 to as 

late as 9/22. As would be expected, the last whale of the season was struck earliest for the two 

shortest seasons documented by the project, and also the two seasons when whales were 

arguably closest to Cross Island. Whalers reported that whales were close to Cross Island in both 

these years. All seasons ended either a few days after the quota was filled (to allow for 

butchering and packing) or if the quota had not yet been filled, when the whaling captains 

determined that conditions were such that it was not wise to remain at Cross Island any longer 

(freeze-up imminent or weather inclement). Of the project seasons, only in 2001 was the day the 

last whale was struck for that season after the average day for the end of the season for all seven 

seasons. 2001 was also the season with the latest ending date. 

Table 3-56 summarizes some measures that one might expect to influence or be related to the 

duration of Cross Island whaling seasons – mainly weather conditions (number of “weather 

days”) and measures of the relative number and distance of whales in the proximity of Cross 

Island. Missing from this table is a quantitative measure of ice conditions. Ice as a factor will be 

discussed in a later section in qualitative terms, because ice was a factor mainly due to its 

absence. “Weather days” is a label mainly for days when the wind was too strong for the boats to 

go out looking for whales. In the absence of ice, any wind over 10 miles per hour (mph) can 

create sea conditions making seeing and striking a whale, and then towing it to Cross island, 

difficult. The presence of the edge of the shelf ice dampens the height of waves and swells 

created by wind. Nuiqsut whalers will go out scouting for whales when winds are over 10 mph 

and there is little or no ice, but such conditions are marginal and whalers scout in such conditions 

only when prospects for improved conditions are slight. Floating ice floes may have been a 

factor in 2001, and local ice conditions were certainly a factor in 2005 and 2006. 
220 

Table 3-56, Measures related to weather and whale distribution affecting the Cross Island 

subsistence whale hunt, 2001 through 2007. From Galginaitis et al. (2009). 

Season 2001 2002 2003 2004 2005 2006 2007 Average 

Duration (days) 24 23 19 301 27 21 13 22.4 

# Weather Days 8 4 8 131 13 4 3 7.5 

# Days Scouting 12 15 7 12 9 10 5 10.0 

# Days Whales Seen 9 9 7 6 7 8 4 7.1 

Av Length of Trip (miles) 83.9 64.3 37.2 45.3 60.7 60.8 30.1 58.5 

Duration of Trip (Hr:Min) 9:43 7:58 4:31 6:51 7:07 8:13 5:57 7:32 

Av Farthest Point from Cross 

Island (miles) 23.6 19.5 11.6 12.1 19.1 22.3 10.4 18.1 

Average Strike Distance from 

Cross Island (miles) 19.5 13.4 9.3 9.7 25.9 17.0 12.0 13.9 

1

Not included in this total are an additional 5 days when no one was present on Cross Island. The whaling crew that 

had gone out early returned to Nuiqsut to wait out a period when extremely bad weather was expected. 

Of course Nuiqsut whalers' observations of whales near Cross Island are only representative of 

the area where they are actually looking for whales, and are by no means a measure of the total 

bowhead population or of the migration route in general. The whalers report that prior to oil and 

gas development, the whale migration passed close to Cross Island and even inside of the barrier 

islands sometimes. They no longer see many whales inside the barrier islands and note that, in 

some years, whales are closer to Cross Island than they are in other years. 

The number of “Weather Days” – days when all Nuiqsut whaling captains decided that 

conditions were not suitable to go out whaling – have an obvious relationship to the total length 

of a whaling season. They are only one factor, and not the entire story, however. While the 

longer duration seasons tend to have had more weather days, seasons with relatively few weather 

days (3-4) ranged in duration from 13 to 23 days. Overall conditions may be good for scouting, 

but whales may not be present. Whales could be present, but in low numbers and/or at relatively 

great distances so that they are relatively hard to find. The whales that are seen could be 

behaving in ways that make them difficult to follow and approach. Thus, season length can be 

expected to be quite variable and dependent on a number of factors, of which weather is just one. 

The number of “Scouting Days” (days when the whalers go out looking for whales) is also 

clearly related to the duration of the season, and is not independent of “weather days.” The 

normative expectation, as reported by whaling captains and experienced whaling crew members, 

is to take one whale on any given day that boats go out scouting, although in recent years two 

whales are not uncommonly landed at Cross Island on the same day. Thus, the minimum number 

of scouting days expected for a Cross Island season would be 2-4. Any number over 4 represents 

an extension over the ideal “shortest season”. The number of scouting days does seem to 

correspond well with the duration of the overall season. The shortest season (2007, lasting 13 

days) had 5 scouting days and 3 weather days. The next shortest season (2003, lasting 19 days) 

had 7 scouting days and 8 weather days. Both of these seasons had a high percentage of scouting 

days on which whales were actually seen (80 percent for 2007, 100 percent for 2003). The 

difference between the two seasons seems to be relatable to weather. The three seasons ranging 
221 

from 21 to 24 days in duration (2001, 2002, 2006) had far more scouting days than the shortest 

two seasons, ranging from 10 to 15. Two of these seasons (2002 and 2006) had relatively few 

weather days while 2001 had a relatively high number of weather days. Whales were seen on 

only 60 percent of scouting days in 2002, and on 75 and 80 percent of such days in 2001 and 

2006. The two longest seasons (2004, 2005 of 30 and 27 days in duration) had 12 and 9 scouting 

days, but whalers actually saw whales on only 50 and 78 percent of those days, respectively. 

Furthermore, each had 13 weather days. Seasons differ in the number of days on which whalers 

saw whales but were not able to strike one, from 1 in 2007 (the shortest season) to 6 for 2001 and 

2005, one a long season but the other close to “average” in length. The longest season, 2004, had 

only 3 days when whales were seen that a strike was not made, but only had 6 total scouting days 

and 10 weather days. There are two or three factors that would seem to contribute to this sort of 

variation. A larger number of days when whalers go out looking for whales but do not report 

seeing any may be due to the relative local scarcity of whales, scouting in conditions marginal 

for seeing whales, or a combination of the two, for that season. A larger number of days when 

whales are seen but a strike is not made may be due to more difficulty in following or 

approaching whales for that season than for seasons with fewer such days, and could be due to 

weather and ice conditions, “skittish” whale behavior, or a combination of the two. An estimate 

of the overall “skittish” behavior of whales is difficult if not impossible to quantify, but whalers 

made many more comments about skittish whale behavior in 2001 than for any other season, and 

also commonly remarked on such behavior in 2002. 

The measures related to the distance whales were found from Cross island generally support the 

discussion above – although the 2005 season has some unique characteristics that must be taken 

into account. “Average Length of Trip” and “Average Farthest point from Cross Island” seem to 

be the better measures of the distance of whales from Cross island for a specific whaling season. 

Whalers in general do not travel further from Cross Island to find whales than necessary for a 

number of reasons. One is the often cited “principle of least effort” but at least equally as 

importantly is a concern for safety. Whalers constantly remind less experienced whalers (and the 

researcher) that the weather is very changeable and that the further from Cross Island boats 

travel, the more danger they are in if conditions change and the more difficult towing a whale 

would be. Resources at Cross Island are also finite (fuel, food, water) and whalers have made an 

explicit effort in recent years to whale efficiently. There has been an increased willingness on the 

part of Nuiqsut whalers to land more than one whale on the same day, or multiple whales on 

successive days, than in the past. Good whaling conditions cannot be assumed for the future, so 

the most is made of current conditions when they are favorable. “Average Duration of Trip” is 

affected by the time required for tows (for 2007 in particular) as well as by the average speed 

during the other parts of the trip (some trips are almost all at “scouting speed” while others have 

significant periods of high speed travel). “Average Strike Distance from Cross Island” is 

generally not as reliable a measure since it is an average of only 3 to 5 (or in the case of 2005 

only 1) boat trip versus all boat trips for the year for the first two measures discussed above. 

Comparing each of the seasonal average values to the overall average value for these first two 

measures (58.5 miles for the average boat trip, 18.1 miles as the farthest point from Cross Island) 

seem to indicate that whales were closer to Cross Island in 2007 than in previous years – which 

supports the observations frequently made by the whalers in 2007 that the whales were closer to 

Cross Island than in previous years. The average strike made in 2007 was further out than for 

two other seasons (2003 and 2004), at 12.0 miles, however, because of the number of shorter 
222 

scouting trips in 2007. 2003 had an average boat trip of 37.2 miles and an average farthest point 

of 11.6 miles, with the average strike at 9.3 miles from Cross Island. 2004 had an average boat 

trip of 45.3 miles and an average farthest point of 12.1 miles, with an average strike distance of 

9.7 miles. Both were years when weather conditions were quite poor. Whales were relatively 

difficult to spot and follow, but more so in 2004 than in 2003. Whales were seen on all scouting 

days in 2003, but only on 50 percent of scouting days in 2004. 2004 would have been about the 

same in terms of measures as 2003 if the first part of the season, when only one whaling crew 

was out at Cross Island from 8/15-8/19 and then back in Nuiqsut for 8/20-8/24 were excluded. 

The 2002, 2005, and 2006 seasons are all similar in terms of average mileage of boat trip and 

average farthest point reached from Cross Island, ranging from 60.7 to 64.3 miles for the first 

and 19.1 to 22.3 miles for the second. The three seasons were quite different, however, or at least 

each had a different distribution of whales and other factors they had to deal with. The difference 

in “Average Strike Distance from Cross Island” values for the three seasons reflect these 

differences. In 2002 whalers reported that the whales were closer than they had been in 2001, but 

still farther out than “normal.” There also were far fewer whales than the whalers expected to 

see. Whalers only saw whales on 60 percent of the days they went out scouting. Whales were 

sparse and somewhat skittish (but again, not as much as in 2001). Thus in 2002, whalers had to 

cover a relatively big area and long distance to find whales, but when they did find them they 

were relatively close to Cross Island. The average strike in 2002 was 13.4 miles from Cross 

Island. In 2006 whales were somewhat easier to find, but also somewhat farther from Cross 

Island and the average strike distance was 17.0 miles. In 2005 localized ice conditions – packed 

floating ice against the north side of Cross Island – made it impossible for the whalers to travel 

beyond the barrier islands except for two days. On one of these days, sea state conditions made it 

hazardous to boat into open water beyond the ice. On the other day, whales were seen and one 

was landed, but the whalers also encountered a tug and barge that they believe hindered their 

hunt (discussed below). When the whalers were confined within the barrier islands, they were 

limited in where they could travel. The one whale they struck and landed, at 25.9 miles, was 

understandably well beyond the average trip they made in 2005. The whaling crew that took this 

whale did so because it might have been their only chance to take a whale. Other whaling crews, 

thinking that this area was too far from Cross Island, had returned to the island before this whale 

was struck. These whaling crews then scouted to the NW of Cross Island and found whales at a 

closer distance – but only after the whale had already been struck to the east. The senior Nuiqsut 

whaling captains did not want to risk striking two whales on the same day, given the distances 

and ice conditions involved for the first whale. 

2001 was the year for which average trip distance was greatest (83.9 miles) and boats on the 

average went farthest from Cross Island (23.6 miles). The average strike was also the farthest 

from Cross Island than for all other years except 2005 (when only one whale was taken) at 19.5 

miles. This reflects the whalers' reports that 2001 was the year when whales were farthest from 

Cross island, were difficult to find because there were not many of them, and hard to approach 

because they were skittish and already traveling fast before the whalers saw them. 

In summary, weather is one determinant of season length, but whalers are patient enough to wait 

for opportunistic “breaks” when they can go out looking for whales. Whalers cannot control the 

weather, but in most seasons they can expect at least a minimal number of days suitable for 

whaling. When those days occur, seasons during which whales are more numerous and/or closer 
223 

to Cross Island tend to result in shorter seasons than when whales are fewer and/or farther away. 

If there is a second complicating factor, such as the ice conditions of 2005 (and the first half of 

2006) that limited where the whalers (and other maritime traffic) could go, seasons are likely to 

longer and the chances of success are greatly diminished. The length of the season, in terms of 

days, is not really an estimate of the level of effort required to land whales; however whales were 

taken for that season, but only the length of time that Nuiqsut whalers had to spend at Cross 

Island that year. The next section considers some other gross measures of Cross Island whaling 

activities that also may reflect more the relatively remote location of Cross Island as a whaling 

site from Nuiqsut than the actual level of effort required to land whales there in any one specific 

season. The section discussing Effort Per Unit Catch, following the next section, attempts to 

define a measure that is comparable for all whaling communities, and essentially defines 

“whaling effort” as the time spent on the water looking for and landing whales – from the time a 

boat leaves shore until the whale is hauled out of the water. While this measure also has 

deficiencies and could be improved, it seems to serve the purpose of providing a rough measure 

to compare the seven seasons documented by this project, and potentially for other whaling 

communities as well, should comparable information be available for those communities. 

3.7.7.4 132BGPS Information 

All whaling crews agreed to carry and use GPS units. The level of information obtained has 

varied from boat to boat, but for most boats and for all whaling crews, at least partial tracking 

information (where most boats went each day) was obtained, along with the locations where 

whales were observed (or struck), from the start of the project. The quality of GPS information 

collected since the 2002 season is actually quite high (Table 3-57). Examples of GPS tracks for 

individual boats on a single day have been presented above (Figure 3-76) and complete tracks for 

all seasons are included in Figure 3-73. 

Table 3-57. Percent of scouting trips by Cross Island whale boats that had GPS track 

documentation, 2001 through 2007. From Galginaitis et al. (2009). 

Season 2001 2002 2003 2004 2005 2006 2007 Total 

Boat Trips 59 67 42 46 48 53 22 337 

GPS Tracks 49 52 37 44 48 51 20 301 

% of Trips with GPS Tracks 83% 78% 88% 96% 100% 96% 91% 89% 

Figure 3-77 shows the locations of the 10 whales landed and the 4 whales struck-and-lost by 

Nuiqsut whalers during 1986-1992. It does not display the locations of the first two whales 

landed by Nuiqsut whalers, in 1973 and 1982. The first was struck near Flaxman Island, within 

the barrier islands. The location of the second has not been identified. The information in Figure 

3-77 was published previously (Long 1996). The locations for the 23 whales landed by Nuiqsut 

whalers during 1993-2000 may be known to the NSB and AEWC, but permission to publish that 

information has not been obtained. The locations of whales struck by Nuiqsut whalers during 

2001-2007, as documented by this project, are discussed below. 
224 

Figure 3-76. GPS tracks for all bowhead whale scouting trips from Cross Island on September 7, 

2007. From Galginaitis et al. (2009). 

Figure 3-77 is included primarily for historical purposes and to highlight two main points. First, 

the quadrant NE of Cross Island is where these strikes are concentrated, and those strikes not 

within this quadrant are either just south or just west of this quadrant. Second, 9 strikes occurred 

within 20 miles of Cross Island, of which only 1 was struck-and-lost. Of the 5 strikes beyond 20 

miles, 3 were struck-and-lost. At least one of these was struck in good weather conditions, but 

was cut loose during the tow when conditions changed and the tow could not be continued 

safely. The whalers attributed this at least in part to the distance of the strike from Cross Island – 

and said that a whale struck closer to Cross Island on that day might have been landed at Cross 

Island. 

Figure 3-73 shows all the GPS tracks collected for all the whaling boats for all years, coded by 

year. This comparison readily shows the variability from year-to-year. The relatively “normal” 

years in terms of distance traveled from Cross Island and direction of travel were 2003 (yellow), 

2004 (blue), and 2007 (white). Whalers reported that in a “normal” year, whales could be found 

within 15 to 20 miles of Cross Island, and that they generally searched for whales in the quadrant 

NE of Cross Island. The patterns for these three years generally meet these conditions. All were 

years when there was little or no ice. 
225 

Figure 3-77. Historic bowhead whale strike locations in the Cross Island/Prudhoe Bay area 

between 1987 and 1992. From Long (1996) as presented in Galginaitis et al. (2009). 

The track patterns for 2001 (purple) and 2002 (maroon) are essentially the three “normal” years 

except that the tracks extend farther from Cross Island, especially for 2001 (Figure 3-73). 

Whalers reported that the whales were the further from Cross Island in 2001 than they had been 

in quite a while, and the measures reported in this document bear them out. Whales were not 

quite as far from Cross Island in 2002 as in 2001, but were still farther from Cross Island than in 

any year documented for the project other than 2001. In both 2001 and 2002 the whalers 

indicated that the whales were not behaving in a normal manner, but were “spooky” – traveling 

fast, difficult to approach, and few in number. Both 2001 and 2000 were relatively ice free, 

although there was more floating ice in these two years than in 2003, 2004, and 2007. Scouting 

effort for these years was also concentrated in the quadrant NE of Cross Island. 

Ice posed a severe constraint to whaling in 2005 (green), but was a localized pack of floating ice 

jammed against the north shore of the barrier islands (Figure 3-73). The ice shelf itself was 

located relatively far offshore. The whalers could not find a way through this jammed floating 

ice for most of the 2005 season. Winds were also relatively high on most days, which also 

contributed to limiting scouting activity to inside of the barrier islands. This explains the pattern 

of mostly SE and NW tracks within the barrier islands. Relatively few whales were seen on these 

scouting trips, and whales within the ice were impossible to approach. One whale was landed on 
226 

one of the two days when boats could find a way through the ice to open water beyond the 

barrier islands. The whalers also encountered a commercial barge on this same day, which may 

have contributed to their only being able to land one whale on this day. On the only other day 

when whalers were able to penetrate through the ice to open water, high swells prevented their 

being able to safely travel beyond the ice, and made spotting whales (let alone following and 

striking them) very difficult in any event. These two days account for all 2005 tracks beyond the 

barrier islands. 2005 was the first year documented by the project during which the whalers 

traveled west of Cross Island to any extent, mainly because the ice prevented them from going 

NE. 

The first half of the 2006 (red) season duplicated the conditions of 2005, and the NW to SE 

pattern of tracks within the barrier island is even more evident than in 2005. When ice conditions 

moderated during the second half of the 2006 season, the track patterns were similar to those of a 

“normal” season except that the tracks extended slightly farther from Cross Island, and a few 

tracks stray somewhat west of the quadrant NE of Cross Island. The whalers were able to land 

their full quota of whales in 2006. Of the seasons discussed in this report, Nuiqsut whalers did 

not fill their quota in 2001, 2004, and 2005. In 2001 the whales were relatively distant from 

Cross Island and not very locally abundant, and the whalers essentially ran out of time and 

landed “only” three of their quota of four. In 2004 the whales were relatively close to Cross 

Island, but poor weather restricted whaling activities and the whalers again ran out of time. In 

2005 ice and weather conditions allowed the whalers only two days of potential scouting beyond 

the barrier islands before time ran out on their season (potential freezeup) and they landed only 

one whale. In six of the seven years, Nuiqsut whalers landed either three or their full quota of 

four whales. 

Figure 3-78, showing the whale sighting points for 2001 through 2007, demonstrates several 

main points, and then some comparative points of one year versus another. First, whales were 

seen where the whalers went and looked for them. Whales could very well have been where the 

whalers did not go, but the whalers were not there to see them. Second, the number of points for 

any given year roughly reflects the whalers’ assessments of the numbers of whales they saw, but 

can be taken only as a minimum number of whales seen. As discussed in the methodology 

section, not all whales seen by the whalers were marked, and some points represent more than 

one whale. Third, there tended to be one or two days in each season (other than 2001 and 2002) 

when whale sightings were much more frequent than on other days. These sightings tend to form 

clusters (even though duplicate sightings have been eliminated as far as possible). Fourth, whale 

sightings are concentrated in the quadrant NE of Cross Island, where whalers search for whales 

most frequently and where the tracks are concentrated, but sightings are also located NW and SE 

of Cross Island, with some inside of the barrier islands. 

Discussing the whale sighting points in comparative terms can only be done in a qualitative and 

speculative way, since the points do not represent all the whales seen for any given year, and 

may represent a different percentage or sample of the whales seen for year. With that 

understanding, the points were collected with the same methodology and from many of the same 

observers from year-to-year, so that they are at least in some sense comparable. 
227 

Figure 3-78. Bowhead whale strike locations near Cross Island between 2001 and 2007. From 

Galginaitis et al. (2009). 

It does appear that the whale sighting points for the “normal” years of 2007, 2003, and 2004 are 

closer to Cross Island than form the other years. This does not mean that for those three years 

that whales were not also present in the locations noted for other years of the project, since for 

the three years in question the whalers did not go out that far. It does indicate that for the other 

years of the project, not as many whales were seen close to Cross Island as for these three years, 

even though whalers had to traverse those waters closer to Cross Island on their way to the 

locations where they did note seeing whales. 

Note that there are some whale sightings relatively close to Cross Island for both 2002 and 2001, 

but that most whale sighting points for those years are farther out (and especially for 2001). Once 

ice conditions moderated in 2006, whales were located somewhat farther out than during the 

three “normal” years. The whales seen on the two days when whalers were able to travel beyond 

the ice (and the barrier islands) in 2005 were also located at this general distance, both to the NW 

and NE of Cross Island. Comparing the 2005 and 2006 whale sighting points, it is interesting that 

far more whales were reported along and within the barrier islands in 2005 than in 2006, 

although there was far more searching effort in this area in 2006 than in 2005. 
228 

Figure 3-78 displays the strike locations for each of the seasons, coded by year. Nearly all strikes 

were within the quadrant NE of Cross Island, with the only exceptions being those slightly south 

of this quadrant. The average strike distance for all strikes for all years was 13.9 miles from 

Cross Island – which corresponds with the whalers’ reports that for most years they land whales 

10 to 15 miles from Cross Island, and that in “good” years they find and land whales within 10 

miles of Cross Island. The years with the closest average strikes were, as might be expected, the 

three “normal” years of 2003, 2004, and 2007 – although strikes in 2003 and 2004 were 

significantly closer to Cross Island (9.3 and 9.7 miles) than those in 2007 (12.0 miles). The 

atypical season of 2005, when only one whale was landed, and the 2007 season were the only 

seasons for which the average strike distance for the season was greater than the average greatest 

distance away from Cross Island reached on all whaling trips. For 2005 this reflects that only one 

struck was made, relatively far from Cross Island. For 2007 it probably reflects the generally 

poor weather encountered for most of the season and the inability to follow and strike whales 

except on days with somewhat better conditions, when whalers were able to travel a bit farther 

from Cross Island. On the other hand, weather was also poor for the 2003 and 2004 seasons, so 

there were probably some idiosyncratic or chance factors in play as well. The average strike 

distance for 2002 was also less than the average for all seasons, at 13.4 miles from Cross Island. 

The three seasons for which the average strike distance was greater than the average for all 

seasons all had some characteristics that set them apart from the other seasons. Ice restricted 

where the whalers could go for most of the 2005 season, and the one strike was made when they 

finally could get beyond the ice, nearly 26 miles from Cross Island. According to many Nuiqsut 

whalers, this is near the limit where a prudent Cross Island whaler will make a strike (25 to 30 

miles), since beyond this range the tow becomes too long. The average tow speed under even 

ideal conditions is 3 to 4 miles per hour, and sea and weather conditions can change too quickly 

to willingly risk many long tows. In 2005, much of the tow could take place with the protection 

of floating ice, which dampens the effect of wind and sea state, but can present its own problems 

for towing a whale. In any event, in 2005 whalers could not reach whales any closer than about 

26 miles from Cross Island. In 2001, the whalers reported that most whales they saw were farther 

from Cross Island than “normal,” were traveling at a greater speed than usual, and seemed 

“skittish” or behaviorally disturbed even before they encountered the whalers’ boats. The 

measures of the 2001 season bear this out, as the whalers’ trips for 2001 were the longest both in 

terms of distance and time duration of all the season documented. The average strike distance for 

2001 was 19.5 miles from Cross Island. The 2006 season started out as did the 2005 season. 

Floating pack ice jammed against the north shore of the barrier island and prevented the whalers 

from reaching open water beyond the barrier islands for the first half of the season. Ice 

conditions moderated for the second half of the 2006 season, but whales were encountered and 

struck at greater distances from Cross Island than the 2002-2004 and 2007 seasons. Whether this 

was a residual effect of the ice conditions of the first half of the season or due to other factors 

was not clear. As discussed above, the whalers reported seeing whales at about the same distance 

from Cross Island in both 2005 and 2006, once they could travel outside the barrier islands. 

3.7.7.5 13BEffects of Weather on Subsistence Whaling at Cross Island 

The next seven figures are graphical summaries of key characteristics for each of the Cross 

Island subsistence whaling seasons documented by this report, 2001-2007. Each figure presents 

the information for one season. The factors that influence the success and length of a Cross 

Island subsistence whaling season, and how they interact, may perhaps be best understood by 
229 

explaining and discussing each in turn. The X-axis for each diagram represents the length of the 

Cross Island whaling season for the year in question, with units of 1 calendar day. Since seasons 

differed in length as well as starting and ending dates, the scales for the figures are not the same. 

The starting date of the whaling season was defined as the date that the first whaling crew 

arrived at Cross Island, and the ending date was the date the last whaling crew left Cross Island. 

The Y-axis for each figure is used to display two scales. The one on the right side of each figure 

denotes wind speed in miles per hour, while the left scale denotes barometric pressure in inches 

of mercury. Six sorts of data are plotted on each figure, except for 2001 which only has four data 

series plotted since there was no weather station at Cross Island in 2001: 

 Wind speed from the Deadhorse weather station (average hourly values) – in blue 

 Wind speed from the Cross Island weather station (readings every 4 minutes) – in teal 

 Barometric pressure from the Deadhorse weather station – in black 

 Barometric pressure from the Cross Island weather station – in light purple 

 Periods when Cross Island whalers were out on the water whaling, from when the first 

whaling crew left the island on a given day until the last whaling crew returned for the 

day, plotted at the value of the average wind speed for that period of time as measured by 

the Cross Island weather station (or if that information was lacking, the Deadhorse 

weather station) – in red. 

 Whale strikes, plotted at the time of the strike and the wind speed at the time of the strike, 

as measured by the Cross Island weather station (or in its absence, the Deadhorse weather 

station) – yellow triangles. 

The plotted information does not provide a complete description of each season, but provides the 

most essential information – the length of the season, when whalers were out whaling, the time 

and date of strikes, and wind speed and barometric pressure when whaling could take place and 

when it could not. Wind direction and temperature information are also available and are 

included in the data appendices provided electronically for each annual report, but are not plotted 

as they did not seem to have much explanatory power. 

The approximate nature of the time and location that whale strikes occur has been noted above. 

They are not precise in terms of exact time and place, but are quite close approximations based 

on the best reconciliation of various sorts of information – Communication Center log records of 

whaler reports, field notes of radio communications, and whaler GPS information. The available 

weather information is also only a proxy for the weather as experienced by the whalers. Wind 

speeds at Cross Island and Deadhorse tend to correspond with each other, especially in terms of 

overall patterns of increase and decrease, but as the figures show, can also often greatly diverge 

at times. Similarly, wind speed as experienced “on-the-water” by the whalers can differ from 

either of these time series records, although the whalers report that the wind speed at Cross 

Island does tend to correspond with what they experience while whaling. While they are out 

whaling they are careful to monitor the wind speed at Cross Island, however, as changes (and 

especially wind increases) that take place there and are not evident further offshore where they 

are whaling can signal sudden changes that indicate they should think about returning to the 

island. Barometric pressure for the two weather stations tended to correspond well, but the 

Deadhorse data covered a much longer part of each season. In the interests of clearer figures, the 
230 

Cross Island barometric pressure data is plotted in a light color so that it can be compared with 

the Deadhorse information without cluttering up the display of the other information. Increasing 

barometric pressure was usually associated with reduced wind speed, and vice versa, but not 

always. Since winds could be calm for a period of hours for any large change in pressure or 

weather system, whalers would sometimes whale during a period of decreasing barometric 

pressure, knowing that they would have a short period of good scouting conditions before facing 

a likely longer period when they could not go scouting. 

In 2001 (Figure 3-79), the first whaling crews arrived on Cross Island on September 3 during a 

period of low winds, but wind speed increased and prevented any scouting for whales until the 

middle of September 5. This allowed the two whaling crews on Cross Island to land the first 

whale of the season on September 5 in moderate winds (about 8 miles per hour). The two other 

whaling crews traveled to Cross Island on September 6 as winds continued to be moderate at 10-

15 mph. The whaling crew that had landed the whale the previous day stayed in to butcher, but 

the other crew already on Cross Island sent one of their two boats out to scout for whales while 

the rest of their crew stayed on the island to help butcher. On September 7, winds were moderate 

and remained so through September 10, below 15 mph for the most part, with barometric 

pressure peaking about September 9 and only starting to decrease sharply around September 11. 

All whaling crews went out scouting on all days from September 7-10 and a whale was landed 

on September 10, during a period when wind speeds were low (5 or 6 mph). All whaling crews 

stayed in to butcher the next two days, during a period of decreasing barometric pressure and 

fluctuating winds. All whaling crews went out scouting on September 13, as butchering had been 

completed and winds were moderate, although increasing. Two whaling crews each sent one 

boat out scouting the next day, but most captains chose to stay onshore, thinking that winds 

would increase still more. Instead, winds calmed late in the day and the barometric pressure was 

rising, so all whaling crews sent boats out scouting on September 15. Winds increased, however, 

and the boats experienced rough seas, so most came in after relatively short trips. All boats 

stayed onshore the next three days as winds remained above 15 mph for the most part, and 

peaked at just under 30 mph. Winds decreased on September 19 and two whaling crews sent 

boats out scouting, and all whaling crews sent boats out on September 20. On both these days 

conditions were not good for whaling, however, perhaps because of standing swells remaining 

from the past windy period. Winds peaked over 30 mph September 21 and all boat stayed 

onshore. On September 22 winds were less (below 10 mph, even though barometric pressure was 

decreasing) and all whaling crews sent out boats and a third whale was landed. All boats stayed 

onshore to butcher the next day (when it was windy in any event) and it remained windy (close 

to 25 mph) for September 24-25. With three whales landed and fully processed, and the 

prospects of deteriorating weather and possible freezeup, the whalers called an end to their 

season and reserved their last strike for a future season. They left for Nuiqsut on September 26, 

on a day with calm winds and had an uneventful and easy trip back to Nuiqsut. 

One of the reasons this season was longer than average, even though the weather was not notably 

bad, was that the whale migration was relatively far from Cross Island, and the whales were 

difficult to find and approach. The whalers used only three of their four strikes in 2001, but went 

scouting on 12 different days. They saw no whales on three of these days. The whalers stated 

that there seemed to be fewer whales in the area, and those that were there were farther from 

Cross Island than “normal” and were swimming faster and acted in a “skittish” manner. The 

further from Cross Island the whalers go, the rougher sea conditions for the same wind speed 
231 

tend to become. In 2001 there was some floating ice offshore, but not enough to moderate the 

effect of the wind. Most scouting in 2001 took place when winds were 10 mph or below, and 

trips except on one day were when winds were below 15 mph (and that day may have been a 

calculated gamble). All strikes took place when wind speed was 7 mph or less. 

In 2002 (Figure 3-80) the overall wind pattern was similar to that of 2001, at least superficially. 

Overall wind speed varied within the same range, but did not maintain high speeds for the 

periods of time it had in 2001 – until the end of the season. There were no spans of several days 

when scouting activity was not possible. Most scouting activity took place at wind speeds of less 

than 10 mph, as in 2001, again with only one day of scouting when the wind speed was over 15 

mph (by only one boat). The first whaling crew arrived on Cross Island August 30, earlier than in 

2001 and was probably an explicit decision in order to try to avoid poor weather at the end of the 

season, and to have some “extra” time after the experience of the year before when the whaling 

crews had to leave before completing their quota. They did not see many “early” whales, but did 

not consider this a failed experiment in that the season did not extend past September 20. 

The whalers used five strikes (their quota and the unused strike from the year before) and landed 

four whales, with one struck-and-lost. Two of their landed whales sank after being struck and 

were recovered as “stinkers.” After they sink, natural processes within a stinker create gas and 

bloat the carcass, so that it floats to the surface. The meat and internal organs from such animals 

are not edible, but the muktuk is still good (and preferred by some Inupiat), as is the baleen. Of 

the five strikes, three were made when wind speeds were 7 mph or less, and all were landed 

(although one sank and was recovered as a stinker). The struck-and-lost whale was struck when 

the wind speed was about 12 mph, and the other whale that sank when the wind speed was just 

under 15 mph. At the time, the whalers did not indicate that wind speed or sea state was a factor 

in either case. When asked, they had no standard explanation for why struck whales sometimes 

sink, other than water entering the lungs and body cavity. The Nuiqsut whalers used their fifth 

strike on September 15, but did not leave Cross Island until September 20. This is explained by 

two of their whales sinking and not being recovered until September 17 and 18 (and this also 

explains the “scouting” activity for two days after the whalers used their last strike). They also 

endured the only period of sustained high winds while recovering the second of these whales, 

and would not have been able to physically leave Cross Island until September 20 anyway. 

The 2002 season was, like the 2001 season, just a little longer than the average for the seven 

seasons documented by this report. There was less floating ice than in 2001, but still some ice 

present. Whales were somewhat closer to Cross Island than in 2001, but not as close as the 

Nuiqsut whalers had come to expect them. The combination of the wind at generally moderate 

(but not low) conditions, and whales at relatively low densities and farther from Cross Island 

than in some other years combined for even more days of scouting activity without a strike (and 

number of scouting days without seeing a whale) in 2002 than in 2001. The 2002 season had the 

highest number of both such days of any of the seven seasons discussed in this report, and also 

the most days of scouting effort overall (15). 
232 

Figure 3-79. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.229.329.429.529.629.729.829.9

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30.130.2

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 

Barometric Pressure (inches Hg)

Day in August/September 2001

Deadhorse Barometric Pressure Whale Strike Boating Deadhorse Win
233 

Figure 3-80. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.129.229.329.429.529.629.729.829.9

30

30.130.230.330.4

30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2

Barometric Pressure (inches Hg)

Day in August/September 2002

Deadhorse Barometric Pressure Cross Island Barometric Pressure BoatingDeadhorse Wind (mph) Cross Island Wind (mph) Whale Strike
234 

The 2003 season (Figure 3-81) was the second shortest of the seven discussed in this report. It 

was characterized by the whalers as one of poor weather, with whales “close” to Cross Island. 

The first whaling crew arrived on Cross Island August 23, again as an experiment to avoid poor 

weather in September and to determine if whales were present near Cross Island that early. 

Weather conditions, mainly wind over 20 mph, prevented scouting on all but two days through 

August 31 (winds moderated on August 25 to below 10 mph, and an attempt was made to scout 

on August 27 even though winds were 15-20 mph). Conditions still allowed two other whaling 

crews to reach Cross Island during this period. All whaling crews went scouting on September 1, 

with winds moderated to below 10 mph, and landed a whale close to Cross Island. Including the 

tow, the trip was a little over four hours for the successful whaling crew. Winds increased to 

almost 25 mph once this whale had arrived at Cross Island, but then decreased to less than 5 mph 

late on September 2 and all whaling crews except the one who had landed the whale the day 

before went out scouting. These trips were short, due to lack of daylight. The next day, 

September 3, increased winds of 10 to 15 mph kept all but one whaling crew onshore, and that 

crew scouted for less than 3 hours before returning to Cross Island. On September 4 winds were 

over 30 mph and no whaling crews went scouting. Winds decreased early on September 5 to less 

than 10 mph and all whaling crews took advantage of the conditions to go scouting, and, once 

one whale was struck and landed the captains decided to take advantage of conditions and try for 

a second on the same day, and were successful in doing so. Winds increased to nearly 20 mph 

once these whales reached Cross Island, but the wind again decreased to nearly calm very early 

on September 6, then increased throughout the day to almost 20 mph, and decreased to nearly 

calm late in the day. The captains again decided to take advantage of the period of calm, 

knowing that the whales were close to Cross Island, and three whaling crews went out scouting, 

including the crew that had landed one of the whales the day before. Butchering on both these 

whales had advanced reasonably far, but the whalers were also anxious not to “waste” the little 

good weather they were having. They landed and towed their fourth whale with winds of 5-10 

mph, and again winds increased once the whale reached Cross Island. Winds remained high (15 

mph or more) until September 9, when all but one whaling crews left for Nuiqsut. The last 

whaling crew stayed another day and left for Nuiqsut September 10. The whalers had been out 

scouting on only seven different days, seeing whales all seven days and striking whales on three 

of those days. Although winds were consistently high during the 2003 season, the whalers were 

able to take advantage of relatively brief (4 to 6 hour) periods when the wind speed was lower, 

shifting, or variable. These periods tended to correspond with peaks in the barometric pressure 

prior to steep decreases. If whales had not been relatively close to Cross Island, these “weather 

breaks” may not have been long enough to strike, land, and tow a whale back to Cross Island. 

Most scouting trips in 2003 took place during winds of 10 mph or less, with one day of scouting 

by one whaling crew when winds were 15-20 mph. All strikes took place when the wind speed at 

Cross Island was 7 mph or less, three of the four with wind speeds of less than 5 mph, and one at 

near dead calm. 
235 

Figure 3-81. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.229.329.429.529.629.729.829.9

30

30.130.2

23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 

Barometric Pressure (inches Hg)

Day in August/September 2003

Deadhorse Barometric Pressure Cross Island Barometric Pressure BoatingDeadhorse Wind (mph) Cross Island Wind (mph) Whale Strike
236 

The 2004 season (Figure3-82) was the longest season for the seven discussed in this report, but 

primarily because one whaling crew went out to Cross Island on August 15, encountered high 

winds and poor scouting conditions through August 26. They were only able to scout one day, on 

August 17, when winds were 10-15 mph. In the face of a forecast of extended poor weather and 

high winds, having only one boat since their second boat had been disabled and no other whaling 

crews were at Cross Island yet, they returned to Nuiqsut August 19. They returned to Cross 

Island August 25 (with winds still 20 mph or more), and were shorebound August 26. They then 

repaired their second boat but encountered more mechanical problems and adverse wind and 

weather through September 4. Of the ten days from August 26 through September 4, they were 

able to scout on four days, and on three of these days their trips were relatively short because the 

wind increased after they had gone out and conditions became too rough. This was primarily due 

to winds of 20 mph and more. A second whaling crew had arrived on Cross Island August 30, 

when there was a lull in the wind, but then was shorebound for five days through September 4. 

This second whaling crew did not try to scout in the marginal conditions of September 4, even 

though the first whaling crew did make an attempt. On September 4 two additional whaling 

crews were able to travel to Cross Island. 

All four whaling crews scouted for whales on September 5, as winds had moderated to 5 mph or 

so, and a whale was landed (struck when the wind speed was close to zero). Three whaling crews 

scouted on September 6, even though winds had increased to 10-15 mph, as the thought was that 

this was perhaps as good as conditions were likely to be for the rest of the season. A second 

whale was struck and landed in about 10 mph winds. September 7 was too windy (winds above 

20 mph) to whale and people stayed onshore to butcher. Conditions were marginally better 

(winds 10-15 mph with stronger gusts) on September 8 and the two whaling crews who had not 

landed whales went out scouting, but saw no whales. The other two whaling crews stayed 

onshore and continued to butcher their whales. On September 9 conditions were much the same 

and only one whaling crew scouted for whales, but did not see any. The wind decreased late on 

September 9 and was still moderate enough so that all whaling crews went out to scout on 

September 10, but winds increased while they were at sea and, even though they saw whales, no 

strikes were made. All boats were then shorebound for the next three days (September 11-13) by 

winds that peaked at 35 mph. All four whaling crews went scouting on September 14, as winds 

were below 10 mph, and a third whale was landed. The wind increased to more than 20 mph 

soon after this whale was towed to Cross Island, and many of the whalers were quite discouraged 

by the conditions. One captain, having landed a whale while only being able to go out on the 

water three of the fifteen days he had been on Cross Island, decided on season was over. All 

whaling crews were shorebound by high winds on September 15, and the captains jointly 

decided that if conditions were suitable on September 16, those whaling crews who wished to 

could try to complete the quota. If a whale were landed, all whaling crews would stay to help 

butcher it. Otherwise, all whaling crews would leave for Nuiqsut as soon as the whales already 

landed were butchered and packed for transport. Winds did decrease to 5-10 mph and two 

whaling crews decided to go scouting (one crew had already decided not to hunt anymore that 

season while the crew that had taken the third whale stayed in to butcher). These two whaling 

crews saw whales, but made no strikes. Three whaling crews finished packing on September 17 

and left for Nuiqsut. The fourth whaling crew stayed on Cross Island an extra day and left 

September 18. 
237 

Figure 3-82. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.529.629.729.829.9

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30.130.230.330.4

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 

Barometric Pressure (inches Hg)

Day in August/September 2004 Deadhorse Barometric Pressure Cross Island Barometric Pressure Boating Deadhorse Wind (mph) Cross Island Wind (mph) Whale Strike

Day in August/September 2004
238 

The 2004 whaling season had 10 weather days, when no scouting could take place. There were 

12 days when at least one boat did go scouting, but no whale were seen on 6 of these days (the 

same number as in 2002). Whalers noted that whales were close to Cross Island in 2004, but that 

the weather was poor. They again took advantage of relatively brief periods when wind speed 

abated, with all strikes taking place is conditions when the wind speed was 10 mph or less. 

Whalers do not necessarily predict how long a lull in windy conditions will be, but consider, 

when they out on the water, how far they can risk traveling from Cross Island and when 

conditions dictate they should head back in. If the first whaling crew had not gone out to Cross 

Island so early compared to the other whaling crews, the 2004 season would have very similar to 

the 2003 season. 

The 2005 season (Figure 3-83) was another long season characterized by very poor weather 

(high and variable winds) and a pack of floating ice jammed on the north shore of the barrier 

islands that prevented the whalers from traveling beyond the barrier islands on all but two days. 

There were nine days when at least one boat went scouting, but on three of these days only one 

boat went scouting since the first whaling crew arrived on Cross Island August 30 (with only one 

boat) and the second and third whaling crews did not follow until September 4 (and the fourth 

September 6, the fifth September 8). Weather conditions were reasonably suitable for scouting 

prior to September 9, but the ice prevented the whalers from traveling beyond the barrier islands 

and although whales were seen on trips within the barrier islands, no strikes were made. After 

September 8 through September 25 there were only three days suitable for scouting. Winds were 

generally at least 20-25 mph except for September 13-14 and September 21. Ice prevented 

whalers from reaching open water beyond the barrier islands on September 13, but on September 

14 they were able to reach open water both to the SE and NW of Cross Island. A whale was 

struck about 26 miles ENE from Cross Island and due to the distance and ice conditions the 

whaling captains decided that a second whale should not be struck by the boats following whales 

to the NW of Cross Island. The trip to land this whale, from leaving the beach to bringing the 

whale in, lasted about 19 hours. The boats to the ENE of Cross Island had encountered a 

commercial barge prior to finding and striking the whale that they landed, and were of the 

opinion that the presence of the barge contributed to the time it took them to locate and land a 

whale. There is also the possibility that if they had landed a whale quicker that they may have 

decided to try for a second whale on the same day. 

Thus effort was followed by another six days of 20 to 40 mph winds, and then perhaps a 6-hour 

window of 0-10 mph wind within a 24-hour window of 15-20 mph wind on September 21. All 

five whaling crews went out scouting but made no strikes. High swells and wind prevented them 

from being able to safely travel beyond the ice into open water, so that they were not able to 

approach any whales. High winds kept all boats shorebound for September 22-24 and the 

whalers called an end to their season and escaped from Cross Island on September 25. This is the 

one season when conditions made it all but impossible for a whale to be landed. There were 11-

15 weather days, and 9 days on which scouting were made. However, ice conditions made it 

impossible to find or approach whales on 7 of these days, and heavy swells in the open water on 

1 of them, so that there was only 1 day in 2005 on which Nuiqsut whalers had an opportunity to 

land a whale. 
239 

Figure 3-83. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.429.529.629.729.829.9

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30.130.230.3

30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 

Barometric Pressure (inches Hg)

Day in August/September 2005

Deadhorse Barometric Pressure Cross Island Barometric Pressure BoatingDeadhorse Wind (mph) Cross Island Wind (mph) Whale Strike
240 

The 2006 season (Figure 3-84) began in much the same way as had the 2005 season, with 

floating pack ice jammed against the northern shore of the barrier islands and preventing the 

whalers from reaching open water. While winds were not light, they were suitable, for the most 

part, for scouting. Three of the four whaling crews went to Cross Island on the same day, 

September 2 and the fourth on September 4. All spent September 3 making final preparations to 

whale and from September 6 through September 12 all whaling crews went scouting the same 6 

of the 9 days, with winds generally below 10 mph for those 6 days (1 day of 10-15 mph). There 

were 3 weather days due to higher winds. The main problem was that the whalers were confined 

within the barrier islands, and could not reach the open water where most of the whales were. 

They could see whales, but not approach them in the ice, and could not get through the ice to the 

open water. 

The higher winds of September 12 (no scouting that day) may have blown the ice off the barrier 

islands, as the whalers were able to reach open water and scout for whales for the next three 

days, and landed a whale on each of those days (September 13-15). The experience of the most 

recent past had been that poor conditions were more the rule than good conditions, and that the 

most should be made of good conditions. Therefore, the captains made the decision to land as 

many whales as they could take care of in as short a time as possible. All three whales were 

struck and landed in 5-10 mph winds. After the third whale was landed it was decided that 

scouting had to be deferred at least one day to catch up on butchering, and conditions were 

marginal for scouting on September 16-17 in any event. On September 18 all four whaling crews 

went scouting and the fourth whale was landed. Three more days, September 19-21, were 

devoted to butchering and packing and all whaling crews left for Nuiqsut on September 22. 

The 2006 season was not one affected by weather a great deal, as there were only 4 weather 

days. Ice conditions, however, made whaling ineffective from September 2 through September 

12. The functional whaling season in 2006 was September 13-18, after which they whalers had 

to finish butchering and then go back home to Nuiqsut. Most scouting and all strikes were 

conducted in conditions of 5-10 mph winds and although whales were seen on 8 of the 10 days 

when boats went scouting, whales could only be approached in the open water beyond the barrier 

islands September 13-18. 

The 2007 season (Figure 3-85) was quite unusual in that while the whalers characterized the 

weather as generally poor and the sea conditions as rough, they completed their quota and it was 

by far the shortest season, in terms of days, of the seven documented for this report. The key 

characteristic of the season seemed to be that whales could be found close to Cross Island and 

that there were local areas that were not as rough as others. Whalers reported that they could see 

and follow whales close to Cross Island, but then had difficulty if the whales went more than 8 to 

10 miles from Cross Island. Since the average strike distance in 2007 was 12 miles, whalers were 

able to follow some whales farther, but the general point was that beyond a certain point the 

whalers could not see or follow whales, let alone approach to strike. Yet, only five scouting days 

were required to use the Nuiqsut quota of four strikes, and on 2 of these 5 days only three of the 

five whaling crews went scouting, as the other two captains thought that conditions were too 

marginal (winds 15-20 mph) and no strikes were made on those days. 
241 

Figure 3-84. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.229.429.629.8

30

30.2

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 

Barometric Pressure (inches Hg)

Day in September 2006

Deadhorse Barometric Pressure Cross Island Barometric Pressure BoatingDeadhorse Wind (mph) Cross Island Wind (mph) Whale Strike
242 

Figure 3-85. Relationships between weather conditions, bowhead whale scouting trips, and strikes 

From Galginaitis et al. (2009). 

29.529.629.729.829.9

30

30.1

30 31 1 2 3 4 5 6 7 8 9 10 

Barometric Pressure (inches Hg)

Day in August/September 2007

Deadhorse Barometric Pressure Cross Island Barometric Pressure BoatingDeadhorse Wind (mph) Cross Island Wind (mph) Whale Strike
243 

The first two strikes were used when only two whaling crews were on Cross Island, the first to 

land a whale on Aug 31 when the wind may have been 15-20 mph (Deadhorse) and the second 

on September 3 when winds appear to have been 10-15 mph (Deadhorse). The last two strikes 

were both landed on September 7, the only day that all five whaling crews scouted for whales in 

2007 (and the only day of scouting for two of them). The wind peaked near 35 mph on 

September 9 but no boats had considered scouting as the whales landed on September 7 were not 

completely butchered until September 10. The captains met and decided that since the three 

landed whales were all fairly large, they did not need to land a fourth. If they had desired to do 

so, they could have requested an additional strike from the AEWC. As it was, they finished 

packing on September 10 and left for Nuiqsut on September 11. 

The 2007 season had only 3 days lost to weather, and whalers only had to go out 5 days (2 of 

them with marginal conditions) to use their quota of 4 strikes. Sea conditions and wind speeds 

were not particularly favorable, compared to previous years, according to the measures 

developed for this project and the accounts from the whalers. They did report more localized 

variability in the degree of swells in some areas than others, but made no generalizations about 

which areas were rougher than others. Whalers also indicated that whales were closer to Cross 

island than in previous years, but that beyond a certain distance they seemed to vanish. Clearly 

winds of 10 mph or less are conducive to Cross Island whaling success, but they are not essential 

given the right set of circumstances. If whales are not too far from Cross Island, whales can be 

landed even in winds of 15-20 mph – but this may rely on the whalers finding the localized areas 

where the effects of wind and swells are not as pronounced. The most general statement Nuiqsut 

whalers make about this is that the farther one goes from Cross Island, the rougher it gets. 

3.7.7.6 134BWhaling Effort - Number of Whaling Crews, Number of Boats, Boat Crew Size 

The relationship between “whaling crew” and “boat crew” was briefly discussed above. The 

“whaling crew” includes everyone who supports a captain is his whaling effort, and all members 

will usually receive some sort of crewshare once the whaling season is over. The number of 

support crewmembers who do not actually go out to Cross Island varies from one whaling crew 

to another – some have relatively few such members while others have quite a few. Of those 

crewmembers that go out to Cross Island, all are expected to help with butchering and on-island 

work. For some whaling crews, all members who go out to Cross Island may potentially go out 

in the boat scouting for whales – and for one whaling crew the captain encouraged all crew 

members to go out every trip (and there were usually 6 to 8 crew members on Cross Island for 

this crew). Most other whaling crews took no more than 5 or perhaps 6 crew members in a boat 

for scouting, and the more typical number is 3 or 4. On occasion a boat will go out looking for 

whales with a boat crew of only two. For some whaling crews, there may crew members who go 

out to Cross Island and never go out in the boat. 

As discussed above, boats will often go out with more than the minimum of three crew members. 

A number of factors were advanced by whalers to explain their boat crew composition. For 

example, when conditions were rougher or more marginal, or on days when a captain felt a 

greater need for speed than other days, he would go out with fewer crew members in each boat. 

When conditions were optimal or when a captain wished to act more in support of other boats 

rather than to more aggressively seek a first strike, he may take more crew members in a boat. 

Those whaling crews with younger crew members not fully proficient in skills required for 

whaling tended to be larger, to facilitate the transmission of whaling knowledge. When a crew 
244 

member slept late, he was left on shore. None of these relationships or reasons was determinant, 

however. Many interacting factors affected how many crew members went scouting in each boat 

on any given day. 

There is no real “typical” whaling crew on Cross Island – all have unique characteristics that 

contribute to their size and composition. Many captains state the rule that when someone asks if 

he (or she) may go whaling “I never say no.” The reality is that space in the boats to go out to 

Cross Island are limited, since the boat must carry not only the whaling crew members but most 

of what they will need on Cross Island - although this is less true than in the past, due to the 

logistical support and help supplied through the CAA. Under terms of the CAA, almost all of the 

gas and diesel fuel have been provided by industry and barged to the island just before or when 

the whalers get there, along with a generator, water tanks, and large boxes and other materials to 

pack and ship the butchered whale. Some whaling captains (and the researcher) ship food and 

other supplies from Anchorage (or Fairbanks) to Deadhorse, so that they can also be transported 

to Cross Island on this barge, and so save some space on their boats. Still, space in the boats and 

cabins is limited. Those captains with bigger boats, and bigger cabins, are less limited than others 

in terms of whaling crew size. This is one reason that most whaling captains are constantly 

thinking of ways to improve their cabins on Cross Island. 

Table 3-58 presents measures related to the number of whaling crews and boats physically 

present on Cross Island during the seasons documented by the project, as well as the average 

total population of Cross Island and the average boat crew size during that period. As the table 

shows, there was a minimum of 3 whaling crews on Cross Island (2002) and a maximum of 5 

(2003, 2007) in this period, an average of 4.1 per season. To some extent this is a number 

without much meaning – the more meaningful number is the number of whaling boats present on 

Cross Island. Most Nuiqsut whaling crews (18 of 29, or 62 percent) used more than one whaling 

boat (and many also use additional support boats for hauling people and supplies that are not 

used to hunt or tow whales). This allows experienced whalers who do not want to, or are not yet 

able to afford to, register as a captain to essentially run a boat under the overall management of a 

registered whaling captain. Some individuals may have whaled as captains in the past but be 

currently unable or unwilling to assume the economic responsibilities of fielding a whaling crew 

in a particular year (which include hosting the attendant public events if their whaling crews 

should land a whale). Others may be individuals looking to amass more experience and 

equipment, so that they can eventually field an independent whaling crew. Others may have 

other reasons. 

However that may be, the number of boats capable for whaling has varied from 7 to 11 for 2001-

2007, or an average of 1.9 whaling boats per whaling crew. The numbers from Table 3-58 

indicate that Nuiqsut whalers try to have at least 8 boats available for whaling at Cross Island. In 

2002, with only 3 whaling crews, each crew operated 3 boats (whereas in most years only 1 3-

boat whaling crew would be expected). In 2007, two whaling boats were disabled on the way to 

Cross Island and never used for looking for whales, and so were not counted as whaling boats. 

One reached Cross Island and was used as a support vessel. One was left (and repaired) at West 

Dock and was used on the trip back to Nuiqsut. This leaves only 2006 as a season when Nuiqsut 

whaling captains knew before they reached Cross Island that there would be fewer than 8 

whaling boats. 2006 was a transitional season for one whaling crew, when one captain sat out the 

whaling season and reorganized his whaling crew from a multi-boat to a single-boat operation. 
245 

Table 3-58. Information on the number of whaling crews and boats physically present on Cross 

Island during the 2001 through 2007 whaling seasons, as well as the average total 

population of Cross Island and the average boat crew size during that period. From 

Galginaitis et al. (2009). 

Season 2001 2002 2003 2004 2005 2006 2007 Total Average

# of 1-Boat Whaling Crews 1 0 1 1 3 2 3 11 1.6 

# of 2-Boat Whaling Crews 2 0 1 2 1 1 2 9 1.3 

# of 3-Boat Whaling Crews 1 3 2 1 1 1 0 9 1.3 

Total Whaling Crews (Max. #) 4 3 4 4 5 4 5 29 4.1 

Average Whaling Crews on Cross 

Island (average for the full 

season) 

3.8 2.5 2.8 2.6 4.1 4.0 4.0 3.3 

Total Boats (Max.) 8 9 9 8 8 7 7 56 8.0 

Average Boats Scouting/Day1 4.8 4.3 4.9 3.4 4.0 4.8 3.2 4.2 

Average Boats Scouting/Strike2 5.3 4.8 6.3 5.7 8.0 3.8 4.3 5.1 

Average Cross Island Pop 27.7 26.6 20.4 16.2 29.8 29.2 26.0 24.8 

Average Whaling Crew Size 7.3 10.6 7.3 6.2 7.3 7.3 6.5 7.5 

Average Boat Crew Size 3.9 3.6 2.9 3.6 4.4 4.3 4.3 3.9 

1

Average number of boats out scouting for whales for all scouting day 

2

Average number of boats participating in the hunt that resulted in a struck whale 

The 2005 season was exceptional in that only one strike was made, on a day when all the 

whaling boats on the island were available to go out scouting. Even excluding 2005, however, 

there is some evidence for a trend of fewer boats available for whaling over the period of 2001-

2007. There is also an apparent declining trend for the maximum number of boats present on 

Cross Island potentially able to whale from 2001 to 2007. This is a gross indication that total 

level of effort may have similarly declined. Other measures examined in the next section may 

indicate this is not a strong trend. 

The “Average Boats Scouting/Day” numbers indicate why captains may prefer to have eight or 

more boats available for whaling. Not all captains will necessarily whale on any given day. Some 

captains are more willing to try to whale in marginal conditions than others, but this is usually a 

concern only on a limited number of days. Most whaling crews will not whale the day after 

landing a whale, especially if they have only one boat, since they have butchering 

responsibilities. However, if they are using multiple boats they may send out a boat while 

keeping other crew members onshore to butcher. Whaling crews other than that who landed a 

whale will often seek to go out scouting for whales the next day, if conditions are good and the 

successful captain indicates that he has the butchering in hand. In the more general case, 

however, it is likely that at any given time there will be one or two boats that are experiencing 

some sort of mechanical or other problem. The overall average for each season also reflects 

scouting days before all whaling crews reached Cross Island. It is instructive that for all season 

except 2006 the average number of boats out scouting and participating in a hunt that resulted in 

a struck whale was larger than the general average for all scouting days of the season. What may 

be more remarkable is the magnitude of the difference between the number of boats on Cross 
246 

Island and the number that, on average, actually go out scouting. This reflects mechanical 

problems that keep boats onshore, but also cases where a whaling crew needs to stay onshore to 

butcher while other whaling crews go out to scout, the need for captains to send a boat to 

Nuiqsut with their tavsi after a whale is landed, or the use of boats for other errands such as trips 

to West Dock. 

The average number of people physically present on Cross Island did not vary much from one 

season to another, and only roughly reflects the number of whaling crews on Cross Island. In 

2003, for example, when the number of whaling crews decreased to three, each whaling crew 

used three boats. Some crew members who would normally whale for captains who did not 

whale in 2003 joined other crews for that year. The increase in the average size of whaling crews 

in 2003 (and not in the overall number of boats at Cross island) is consistent with a minimum 

number of boats being available to scout for whales, and a minimum number of people being 

required to go out in the boats and butcher the whales that are landed. It also reflects the dynamic 

that new whaling crews are created when an experienced co-captain “hives off” from an existing 

whaling crew to form a whaling crew of his own. The apparent lower Cross Island populations 

for the 2003 and 2004 seasons actually reflect the relatively long periods of time when only one 

whaling crew was physically present on Cross Island (6 days in 2003 and 9 days in 2004) and the 

relatively few days when all whaling crews were physically present on Cross Island (58 percent 

in 2003 and 50 percent in 2004). This is also evident in the difference between the values of the 

maximum number of whaling crews at Cross Island for any given season (by necessity an integer 

value) and the actual average number of whaling crews present at Cross Island over the entire 

season. This difference, in terms of percentage, ranged from 35 percent for 2004 to 0 percent for 

2006. The 2001 season is the only other season with a difference as low as 5 percent – all the 

others have differences that are 15 percent or greater. 

3.7.7.7 135BWhaling Effort - Boat Days, Boat Hours, and Effort per Unit Catch (EPUC) 

Table 3-59 summarizes the information that will be used to ground the discussion on different 

approaches for estimating the effort per unit catch (EPUC) for Cross Island whaling, and the 

comparison of these metric across seasons. 

The best approach seems to be to compare whaling-crew-days with boat-days and simple length 

of season (Table 3-59). Looking at the number of whaling-crew-days, 2007 appears to be quite 

similar to 2003 and even 2002, as seasons with the lowest values. The overall range is only 52 to 

105, basically a factor of 2. The largest value is for 2005, with only 2004 near the average value, 

and 2006 and 2001 with above average values. Whaling-crew-days/Whale would seem to 

indicate that 2003 and 2002 were the most efficient seasons, with 2007 not too far behind, 

followed by 2006, 2004, 2001, and finally 2005. Looking at boat-days, however, 2007 has by far 

the lowest value, with 2003 and 2005 each having about twice the 2007 value, followed by the 

other four seasons pretty much evenly spaced at intervals of about half the total 2007 value. The 

range is 16 to 65, about a factor of 4. The boat-days/whale ratio indicates that 2007 was the most 

efficient season, followed by 2003 and 2006 with values below the average for all season, and 

the other four seasons above the average (2004, 2002, 2001, and 2005). In terms of the overall 

length of the season, 2007 was the shortest by far at 13 days, followed by four seasons ranging 

from 19 to 24 days long (2003, 2006, 2002, and 2001), and then 2005 and 2004 at 27 and 30 

days. When the seasons are ranked by the average number of days each whaling crew was 
247 

actually present at Cross Island, 2007 again was by far the shortest at 10.4, followed by 2003 at 

13.25, and then the other five seasons with values of 19.34 to 22.5. 

Table 3-59. Measures of Subsistence Whaling Effort by Cross Island Whalers between 2001 and 

2007. From Galginaitis et al. (2009). 

Season 2001 2002 2003 2004 2005 2006 2007 Average 

# of Whales landed 3 4 4 3 1 4 3 3.1 

Struck-and-Lost 0 1 0 0 0 0 1 0.3 

Length of Seasons, Days 24 23 19 30 27 21 13 22.4 

# of Whaling Crews (Max) 4 3 4 4 5 4 5 4.1 

Average Days on Cross 

Island/Whaling Crew 22.5 19.3 13.3 19.3 21 21 10.4 18.1 

Whaling Crew Days (total) 90 58 53 77 105 84 52 75 

Whaling Crew 

Days/Whale 30 14.5 13.3 25.7 105 21 17.3 23.6 

# of Boat-Days 57 65 34 41 35 48 16 42.3 

Boat-Days/Whale 19.0 16.3 8.5 13.7 35.0 12.0 5.3 13.5 

Boat-Days/Strike 19.0 13.0 8.5 13.7 35.0 12.0 4.0 13.6 

Average Duration of 

Scouting Trip 9:43 7:58 4:31 6:51 7:07 8:13 5:57 7:32 

Total Seasonal Effort 

(Boat-Hours) 572.9 533.6 162.9 301.2 341.3 427.1 124.9 351.9 

Boat-Hours/Strike 191 107 41 100 341 107 31 103 

Boat-Hours/Whale 191 133 41 100 341 107 42 112 

It can be argued that the way “whaling-crew-days” and “boat-days” are defined above makes 

them two different sorts of measures and thus not comparable. “Whaling-crew-days” aggregates 

the total number of days each whaling crew was present on Cross Island, whether they went out 

looking for whales or not. “Boat-days” aggregates the total number of days each boat went out 

scouting for whales. However, a measure for whaling-crew-days calculated the same way, 

aggregating the total number of days each whaling crew actually went out whaling, would suffer 

from the same defects of whaling crew composition and size variability discussed above, and 

boat-days calculated as the aggregate number of days each boat was present on Cross Island 

would basically represent the length of season measure (already directly known) rather than a 

measure of active whaling effort. Another way to approach this is to recognize these as measures 

of two different sorts of effort. One is a measure of the total time (including “down time” for 

whatever reason – weather, mechanical, support chores) devoted to an activity, while the other 

focuses on the time spent doing the productive aspects of the activity (“on-the-water” activities). 

The question remains of how best to discuss the seasonal variability of whaling effort. Length of 

season and “whaling-crew-days” as discussed encompass all whaling activities (travel, daily 

chores, scouting and landing whales, towing, butchering and packing) as well as bad weather 

periods, mechanical problems, and so on. While all are significant components of the whaling 

experience of any one season and in combination characterize each season, not all represent 

“effort” in the same way or are as easy to measure. 
248 

Butchering is clearly a component of the total level of whaling effort on Cross Island, but also 

clearly has a direct relationship with the number of whales landed, and no relationship to struckand-lost whales. The work required to butcher a whale is a function of its size, but to accurately 

record the actual labor that is devoted to butcher any given whale is quite difficult. The number 

of people present at the butcher site is constantly in flux, as is the number of people actually 

engaged in the work of butchering. The labor requirements of butchering also clearly influence 

the length of any given whaling season. However, given that Nuiqsut whalers have landed 3 or 4 

whales in all but one of the seasons discussed in this report, the butchering component of the 

whaling effort is relatively constant from one season to the next. It could be argued that if fewer 

people were available to butcher, butchering would take longer, and the length of the whaling 

season would increase. In empirical terms, this has not been the case for the 2001-2007 seasons. 

Individual whales have typically been butchered in 1 to 2 days, with most whaling crews 

participating to some extent in butchering most whales. Because of this logical consistency of 

butchering effort from one season to the next, the difficulty of actually measuring butchering 

effort in any systematic and detailed fashion, and the apparent limited effect on the variability of 

the length of the overall subsistence whaling season, butchering has not been included in the 

EPUC measure discussed below. 

While it can be argued that butchering is certainly a necessary component of processing the 

whale after it is landed, it is not really a component of “catching” the animal – essentially a 

restatement of the argument above. It is the actual level of effort out on the water that is variable 

from one season to another, given a relatively equivalent level of harvest. It is also precisely this 

“on-the-water” aspect of the hunt that is comparable (although not precisely the same) for both 

“landed” and “struck and lost” whales. There is no tow for a “struck-and-lost” whale, and the 

chase for a struck-and-lost whale may be, but is not necessarily, shortened from that of a landed 

whale. Thus, there is a legitimate question as to whether “catch” should refer to “landed whales” 

or “strikes used.” In the strict sense, only “landed whales” are productive results of effort. 

However, it is not uncommon for whalers to indicate that they did nothing different for a landed 

whale than for one that was struck-and-lost. Considering only landed whales as “catch” would 

automatically increase the EPUC in any year with a struck-and-lost whale. However, as is 

evident in Table 3-59, it makes relatively little difference in terms of how seasons compare to 

each other which definition of “catch” is used since Nuiqsut whalers had only two struck-andlost whales in the seven whaling seasons considered here. Ultimately, however, it makes most 

intuitive sense to define “catch” as “landed whales.” While the difference in the calculations of 

the EPUC measure using both possible definitions of “catch” would be a measure of struck-andlost whales as a percentage of all strikes used, this is arrived at far more simply by the direct ratio 

of struck whales actually landed. Since the subsistence bowhead hunt is managed in terms of 

strikes, however, and not landed whales, there may be some justification for calculating Effort 

Per Strike, even if “strike” is not defined as “catch.” That is, the hunt is limited to the number of 

animals that the whalers are allowed to land, and they end their effort when they either reach 

their quota and decide that they have satisfied the community’s need and do not need to ask for a 

fifth strike, or when it is late in the season and they judge that conditions for whaling are poor or 

dangerous and not likely to improve. In the past, if Nuiqsut whalers had not filled their quota, 

they would sometimes stay out at Cross Island waiting for whales until the ocean froze. They no 

longer do so, since in such a case they must leave their boats and retrieve them later. The whalers 

have also noted that weather conditions after September 20 or so generally make whaling very 

difficult near Cross Island. 
249 

It will be argued here that the easiest component of whaling effort to measure, and the one that 

varies the most from season-to-season, is the “on-the-water” effort of scouting, striking, and 

landing whales. While it is possible to calculate the aggregate number of days each boat is 

present on Cross Island, and to easily identify the subtotals of days boats went out whaling and 

days they did not, it has been quite difficult to always identify exactly why boats did not go out 

whaling. Sometimes it was for mechanical reasons, or because of adverse weather conditions, or 

the need to use the boat for something else. Sometimes the whaling crew had onshore chores to 

complete. Other cases were less clear, however. Sometimes it could have been one of several 

such reasons. On the other hand, when a boat goes out whaling, it is clear that it has done so. It is 

also clear that the completion of the quota is the limiting factor on determining the length of the 

season. Nuiqsut whalers do not stay at Cross Island any longer than they need to after they fill 

their quota or determine that it is not likely that they will be able to do so. “Boat-days” is a direct 

measure of the on-the-water activities required for them to fill their quota. All other onshore 

activities (butchering, packing, chores) are in support of and a result of landing whales. Thus, 

boat-days would appear to be a good proxy measure for overall seasonal whaling effort (and can 

be adjusted if necessary for season length due to poor weather, ice, or other conditions). 

It is possible to measure the level of effort “on the water” in several different ways, with 

different degrees of precision or intuitive validity. Whaling-crew-days and boat-days have been 

discussed above, and while boat-days appear to be a reasonably good measure, the available 

information allows a more refined and precise measure to be developed. From Table 3-53, it is 

clear that the average boat-trip varies significantly both in terms of time duration and total 

distance from season-to-season, so that a “boat-day” does not represent the same amount of 

whaling effort each season (for instance, 4 hours 31 minutes and 37.2 miles in 2003 compared to 

9 hours 43 minutes and 84 miles in 2001). A “boat-day” includes both the temporal and spatial 

aspects of effort, and to refine the measure one could focus on one or the other (or a combination 

of the two). As a measure of effort, time appears to be a better unit than distance. Nuiqsut 

whalers generally scout for whales at 4 or 5 miles per hour and reserve high-speed for traveling 

to a likely place to spot whales or for returning to Cross Island after not deciding to stop looking 

for whales on any given trip. On many trips Nuiqsut whalers will maintain “scouting speed” for 

the entire trip, as whales can be found very close to Cross Island and could be missed if they 

were traveling at high speed. A measure of effort based on distance would result in larger values 

for seasons when whales were more distant from Cross Island, regardless of the speed of travel. 

A measure of effort based on time would also appear to result in larger values for seasons when 

whales were more distant from Cross Island, and this does appear to be the case in general, but 

for those seasons when whales were generally more distant from Cross Island than other seasons 

(2001 and 2002), whalers tended to travel at high speeds until they were out to where they had 

been seeing whales before they slowed to “scouting speed.” Distance appears to represent more 

where whales were found than effort as such, and is incorporated into the time measure. Further, 

travel at higher speeds (when scouting for whales is less effective) contributes less to a timebased measure than to a distance-based measure, so time rather than distance may be preferable 

for a measure. 

Table 3-59 shows values for total seasonal effort in terms of boat-hours, and clearly indicates 

that 2007 was the season of least on-the-water effort (124.9 boat hours), with the 2001 season 

having the most on-the-water effort (572.9 boat hours). Because of the high seasonal effort in 

2001 and 2002, the effort for the 2003 through 2007 seasons was below the average for all seven 
250 

years of this study (351.9). The 2006 season had about 30 percent more effort than the average 

season, and both the 2002 and 2001 seasons had roughly 70 to 90 percent more effort than the 

average season. In terms of effort per whale landed, the 2007 and 2003 seasons were about the 

same (42 and 41 boat-hours/whale, respectively), since 4 whales were landed in 2003 but only 3 

in 2007 (with one struck and lost). The 2004 season has a value about 150 percent greater the 

2007/2003 values, with the 2006 season value only a little higher (but again, 4 whales landed in 

2006 and only 3 in 2004). The 2002 seasonal value for effort/whale is somewhat higher than for 

the 2006 season, but is about the same for effort/strike, because of a struck-and-lost in 2002. The 

2001 season has the highest effort/whale value for seasons when 3 or more whales were landed 

(191 boat-hours/whale), at somewhat less than twice the values for the 2004/2006/2002 seasons. 

This was the year when whalers (and other measures) indicated that whales were farther from 

Cross Island and seemed to be less numerous than for other seasons. The value for effort/whale 

is of course highest for the 2005 season (341 boat-hours/whale), when only one whale was 

landed due to very poor weather and ice conditions. 

3.7.7.8 136BNon-Whaling Boat Activity 

In addition to searching for whales, Nuiqsut whaling vessels made trips between Cross Island 

and West Dock on a fairly regular basis. These trips were to pick up packages and supplies, or to 

do other errands. Generally, after a whale is butchered, one of the boats from the whaling crew 

that landed it made the trip between Cross Island and Nuiqsut to transport the meat and muktuk 

from the captain’s tavsi to feed the village. Only a few other boats went to Cross Island from 

Nuiqsut other than the whaling boats. These boats were to bring help to butcher one of the 

whales in one case, and in several other cases were to bring or take away whaling crew members 

during the season. There were visitors of other sorts in different years – tourists, adventurers, 

polar bear researchers, and industry representatives on various missions or just on a sight-seeing 

visit. The people from these boats generally stayed for the day, or perhaps a night or two. 

Visitors from Nuiqsut generally stayed a bit longer - a day or two before returning to Nuiqsut, 

and helped with whatever tasks needed to be done (especially the butchering of the second whale 

in 2001). New whaling crew members generally stayed for the rest of the season. 

This project focuses explicitly on Cross Island whaling activity, so little attempt was made to 

collect systematic information on these non-whaling activities or visitors. Also, information on 

preparation, support, or other whaling crew member activities that occurred elsewhere (primarily 

in Nuiqsut, one would assume) were not documented as part of this project. That remains for a 

larger project. There were two “landline” phones on the island during each whaling season 

(which, like the generator, operate only during Cross Island’s whaling season), as well as a FAX. 

Thus, important business need not be put on hold while corporation and other officials are 

whaling on Cross Island. Contacts and interactions through telephone, FAX, or non-whaling 

non-Nuiqsut vessel were not fully documented, and such information was only collected as 

contextual background. Whaling crew members increasingly have cell phones that work from 

Cross Island, but no attempt has been made to measure how this has changed patterns of 

behavior on Cross Island (except through opportunistic observations). Similarly, the pattern of 

use of video-players, DVD players, computers, gameboys and other gaming systems, and other 

such electronic equipment has not been systematically explored. 
251 

3.7.7.9 137BOther Subsistence Activities 

All things considered, very little non-whaling subsistence activity was reported or observed over 

the course of the project at Cross Island during 2001-2007. The most consistent activity of this 

sort is the harvest of polar bears that are attracted to Cross Island by the remains of the butchered 

whales. The skulls of most of the whales landed by Nuiqsut whalers are lined up on the island 

some distance east of the butcher site, and somewhat further is where the rest of whale is 

disposed of, after butchering for human consumption is finished. Sometimes the polar bears 

approach too closely to the butchering activities or to the cabins where the whaling crews live 

while on Cross Island. If non-lethal hazing does not deter these bears sufficiently, they are shot. 

On average, perhaps one polar bear a year is shot for being a nuisance bear. Some years, no bears 

are shot. Other years more than one may be shot, but this would be uncommon. There are cases 

where a whaling crew member will come to Cross Island with the intention to kill a polar bear, 

but to do so he must first obtain the permission of his whaling captain. Most whaling captains 

consider whaling as the first priority while out at Cross Island, and butchering a polar bear and 

taking care of its hide is a great deal of work that would take a crew member away from whaling 

duties. A whaling crew member also has to be aware that even if he kills a polar bear and takes 

care of the butchering and hide, his whaling captain can claim the hide for himself, should he 

wish to do so. 

Some sealing has taken place during a few years, but not every year. Whalers will sometimes 

look for a seal on the way back from scouting for whales, if a whale has not been landed, or will 

make a trip looking for seals around the island on a day when conditions are not suitable for 

scouting for whales. Most such attempts have not resulted is a harvested seal, however – perhaps 

three or four over the seven years described in this report. Some whaling crews will try to harvest 

bearded seal should one appear opportunistically on the boat’s return trips to Cross Island, and 

perhaps two have been taken in this way over the course of seven years. Similarly, one whaling 

crew took a walrus that happened to present itself, some 20 or more miles west of Cross Island. 

The boat crew members in the boat that actually shot the walrus were all young and had never 

taken a walrus before. They did not realize how difficult the tow back to Cross Island would be, 

nor how hard it is to butcher a walrus for the first time. Another walrus with a calf beached on 

Cross Island and died. It was disposed of, after salvaging its tusks. One young walrus followed 

the whalers’ boats into Cross Island one year, and was eventually shot. Vocalizations of other 

walrus have been heard from Cross Island, but only in one or two of the seasons discussed here, 

and walrus are not commonly encountered by Cross island whalers. 

One whaling crew did take a fish net out to Cross Island during one or two of the seasons 

described in this report, but it was never deployed. Whalers say that in the past they fished while 

out on Cross Island at whale camp, and that they would also sometimes go hunting for caribou 

on the mainland, either while traveling to Cross Island or while they were out there. Of course, in 

the past, and especially before the mid-1990s, Cross Island whaling seasons tended to be longer 

and whalers tended to be, or needed to be, more self-sufficient than they are currently. Much 

more can be transported to Cross Island now than in the past, and whalers have more resources 

with which to purchase supplies. Also, current whalers feel more of a time crunch than did 

whalers of the past. Whalers with jobs must often fit their whaling season into a two-week 

envelope of vacation or subsistence leave, whereas whalers of the past could comfortably spend 

more time. 
252 

Some bird hunting also took place, but again only in one or two seasons. For the most part, the 

subsistence food consumed on Cross Island, other than whale, is brought to the island from 

Nuiqsut. The typical whaling crew will bring frozen caribou, frozen fish, perhaps some moose, 

and a wide assortment of “store” food, much of it canned. Perishable food is most often kept in 

coolers on the roofs of the cabins, but a few captains have bought and transported freezers to 

their cabins at Cross Island, to take advantage of the generator provided under the terms of the 

CAA. It may be that the implementation of the CAA has reduced the need for whalers to engage 

in subsistence activities other than whaling while out at Cross Island, and increased their focus 

on whaling and thus shortened the time required for them to fill their quota, than would be the 

case in the absence of the CAA. 

Specific non-whaling subsistence activities that took place during each season are detailed in the 

annual reports for each season. Discussion of these activities was beyond the scope of this study. 
253 

4 3BINTEGRATION OF cANIMIDA PROJECT 

4.1 19BObjectives of ANIMIDA/cANIMIDA 

The primary objectives of the ANIMIDA and cANIMIDA Projects were to monitor and 

characterize the marine environment of the Northstar and Liberty development areas to evaluate 

potential and actual effects of these large offshore oil developments. cANIMIDA was an 

extension of ANIMIDA intended to examine temporal and spatial changes in the marine 

environment in the development area of the Beaufort Sea and to determine if any observed 

changes in chemical, including distribution and abundance of metals and hydrocarbons, and 

biological characteristics, including the ecology of the Boulder Patch and behavior and 

movements of bowhead whales near Cross Island during the fall Nuiqsut whale hunt, in the 

development area were related to the current Northstar development and production operations. 

4.2 20BOffshore Oil and Gas Operations in the Beaufort Sea that Could Cause LongTerm Environmental Disturbance. 

Many operations performed during evaluation, exploration, and development/production of 

offshore oil and gas resources may cause physical disturbance or chemical contamination of the 

marine environment. These include seismic exploration, offshore infrastructure construction, 

drilling and production waste disposal, blowouts and oil spills, and air emissions. 

Seismic exploration may cause temporary disturbance to nearby marine mammals and birds, but, 

if performed properly with modern seismic survey equipment, does not cause any long-term 

damage. 

The longest-lasting disturbance in the Beaufort Sea is from platform, gravel island, and subsea 

pipeline construction and emplacement during exploration, development, and production. These 

activities may cause physical disturbance at the sea floor and may interfere with other uses of the 

local marine environment. Most exploratory drilling and all development operations in the 

Alaskan Beaufort Sea were performed from artificial gravel Islands or grounded drilling 

structures. These structures cause considerable long-lasting physical disturbance to the sea floor, 

effectively smothering all benthic fauna in the area of the facility footprint. They also may alter 

ocean currents, mixing of water masses, and marine animal migratory routes. More than 20 

gravel islands have been constructed since 1975 in waters less than 15 m deep on State and 

State/Federal lease tracts in the Alaskan Beaufort Sea for exploratory drilling and production. 

About 1.6 million metric tons of sand and gravel were used to construct Northstar production 

island. This is equivalent to about one-third of the mass of suspended sediments delivered to the 

Beaufort Sea each year from the Colville River (Trefry et al., 2004a). Most of these islands 

remain in some form. Some of the gravel islands erode away after completion of exploratory 

drilling, spreading coarse sediments over a large area. The gravel islands also may leach 

chemicals, particularly metals, from the gravel material used to construct the island or from small 

spills of drilling chemicals during drilling after the island is abandoned and erodes. Most 

exploration in deeper waters in the Arctic is done from platforms, such as drill ships and 

specialized ice resistant drilling platforms. These drilling structures are anchored to the sea floor 

and the anchors and anchor chains may cause serious sea floor scour. Similar physical 
254 

disturbance to the sea floor may be caused by pipeline emplacement. These physical disturbances 

to the sea floor resemble those from ice scour and spring river floods. 

Large volumes of wastes are generated during drilling of exploratory, production, and workover 

wells. Some of these wastes may be permitted by NPDES permits for discharge into the marine 

environment where they have the potential to cause ecological damage. The wastes produced in 

largest volumes during drilling are drilling muds and drill cuttings. Water based drilling muds 

(WBM) are the only types that have been used and discharged offshore in the Alaskan Beaufort 

Sea. 

Modern WBM are composed of a weighting agent, usually barium sulfate (barite), clay or 

organic polymers, and small amounts of additives suspended in freshwater, seawater, or a saline 

brine. The WBM ingredients of major environmental concern are metals and petroleum 

hydrocarbons. The drill cuttings generated by the drill bit when drilling with WBM also may 

contain metals and hydrocarbons, derived mainly from the geologic strata being penetrated by 

the drill, and usually at concentrations similar to those in local marine sediments. 

Thirty-one exploratory wells were drilled over a period of 23 years (1981 to 2002) on 

State/Federal lease tracts administered by MMS between Barrow and Kaktovik in the Alaskan 

Beaufort Sea. Many additional wells were drilled on nearshore State lease tracts. WBM and 

cuttings were discharged to the Beaufort Sea from most of these wells. The total estimated 

volume of WBM and cuttings discharged from each exploratory well drilled in the Beaufort Sea 

between 1981 and 1997 ranged from about 940 to 2530 m3

/well. If it is assumed that the average 

mud/cuttings discharge from a Beaufort Sea exploratory well is about 1500 m3

/well containing 

an average of 600 metric tons/well of solids and that WBM and cuttings were discharged from 

about 50 wells drilled on State and State/Federal lease tracts since 1981, the total volume of 

drilling mud and cuttings discharged to the Beaufort Sea was about 75,000 m3 and the total mass 

of solids discharged was about 30,000 metric tons. 

The metals frequently found in drilling muds and cuttings that are of greatest concern because of 

their potential toxicity and/or abundance in drilling muds include arsenic, barium, chromium, 

cadmium, copper, iron, lead, mercury, nickel, and zinc. In the past, only barium, chromium, iron, 

lead, and zinc sometimes were present in drilling mud/cuttings solids at concentrations 

significantly higher (> 100-fold) than concentrations in clean marine sediments (Table 4-1). 

However, most of these metals are present as insoluble sulfide inclusions in drilling barite and 

are not bioavailable to marine animals (Neff, 2008). With the imposition of a limit on the 

concentrations of mercury (1 mg/kg) and cadmium (2 mg/kg) in drilling mud barite (EPA, 1993), 

concentrations of most metals have decreased in WBM and cuttings discharged offshore in the 

US; barium (from barite) is the only metal usually found at substantially higher concentrations in 

WBM than in marine sediments (Neff, 2010). All metals, with the exception of barium and 

chromium, were present in the historic Beaufort Sea drilling muds at concentrations similar to 

those in Beaufort Sea sediment and river particulate matter (Table 4-1). 

Total petroleum hydrocarbons, including PAH, sometimes are present in WBM and cuttings at 

concentrations higher than those in river sediments (Table 3-12) and Beaufort Sea sediments 

(Table 3-24). For example, drilling mud and cuttings from several depths in a well drilled off 

Point Arguello, CA, contained 900 to 8000 μg/g total PAH, compared to a range of total PAH 
255 

Table 4-1. Ranges of metal concentrations in water based drilling muds (WBM) used and 

discharged offshore in the Beaufort Sea to drill five exploratory wells between 1973 and 

1983. The exploratory wells were Reindeer Island, Sag Delta 8, Challenge Island, 

Mukluk, and Tern Island. Concentrations are μg/g dry wt. From Neff (2010). Metals 

concentrations in suspended particles in three Arctic Rivers and in Beaufort Sea sediments 

(Tables 3-2 and 3-20) are included for comparison. 

Well Barium Cadmium Chromium Copper Lead Mercury Zinc 

Reindeer 720 - 7640 <0.01 - 

1.5 28 - 176 2.8 - 17 2.4 - 117 

0.017 - 

0.22 42 - 397 

Sag Delta 8 60,000 0.28 19.0 19.0 20 <0.01 380 

Challenge 

Island 

20,000- 

360,000 0.2 590 - 1300 14 - 17 17 - 20 0.04 - 0.08 95 - 140 

Mukluk 9520 - 

33,200 

0.19 - 

0.20 9.2 - 10 NA NA 0.06 - 0.08 NA 

Tern Island 113 - 

259,000 1.7 28 - 37 13 16 - 106 <0.1 130 

River 

Suspended 

Particles 

358 - 1219 NA NA 17.6 - 

45.1 4.0 - 36 NA 81 - 264 

Offshore 

Sediments 16 - 912 0.03 - 0.77 14.7 - 116 3.9 - 46.2 3.7 - 20.3 

0.007 - 

0.11 

15.1 - 

120 

NA, not analyzed. 

concentrations in North Slope river sediments and Beaufort Sea sediments of 8.6 to 2635 ng/g. 

By comparison, mean concentrations of total PAH in surficial sediment samples collected from 

the Beaufort Sea off the Mackenzie River, Canada, ranged from 1930 to 4580 ng/g (Yunker et 

al., 1996). The PAH in WBM and cuttings are primarily from hydrocarbon-rich organic matter 

(e.g., kerogens, shale, and petroleum) in geologic strata penetrated by the drill bit and from 

lubricants and other additives sometimes added to the drilling muds. Current NPDES permits 

prohibit discharge of drilling mud and cuttings containing free oil. 

The PAH in river particulates and Beaufort Sea sediments are from combustion soot (pyrogenic), 

fossil hydrocarbon mixtures (peat, shales, coal, and petroleum) (petrogenic), and biogenic 

(perylene, retene, and simonellite from anaerobic diagenesis of organic matter) (Venkatesan and 

Kaplan, 1982; Anders and Magoon, 1985; Steinhauer and Boehm, 1992; Brown et al., 2004, 

2010). PAH from these sources enter the Beaufort Sea in natural seeps, petroleum spills, river 

runoff, coastal erosion, and aerial deposition. Becker and Manen (1988) document six oil seeps 

on the shore of the Beaufort Sea and on the Chukchi Sea shore, just south of Barrow. The 

Beaufort Sea seeps are, from east to west, at Angun Point, Maning Point on Barter Island, the 

mouth of the Canning River, oil lake on the Colville River, and Cape Simpson. Anders and 

Magoon (1985) identified several additional oil seeps and oil-stained rock shale outcrops across 

the coastal plain of northeastern Alaska. They reported that the oil rich shales along the coast of 

the Alaskan National Wildlife Refuge (ANWR) contained 0.9 to 18.3% TOC and 41 to 4,200 

mg/kg total hydrocarbons. The residues exhibited a wide range of petroleum biomarker ratios, 

indicating a wide diversity of source materials with different maturities. Hydrocarbons, including 

PAH, from these surface deposits probably are being transported into the Beaufort Sea with the 

spring river floods and coastal erosion. 
256 

Drilling muds and cuttings were not discharged to the Beaufort Sea during development of the 

Endicott, Northstar, and probably also the Oooguruk facilities. Some non-aqueous phase drilling 

muds (i.e., synthetic based and oil based muds) were used for development drilling at Endicott 

and Northstar and all drilling wastes were disposed of in waste disposal wells at the drill site or 

transported to shore for onshore disposal (Krieger et al., 2002). The Liberty prospect will be 

developed from the Endicott satellite drilling island (SDI) and probably will dispose of drilling 

muds and cuttings through a disposal well at Endicott or in the Prudhoe Bay field. Therefore, one 

of the original objectives of the BSMP and AMIMIDA Projects, to assess environmental impact 

of offshore drilling mud and cuttings discharges in the Alaskan Beaufort Sea, cannot be 

accomplished. 

Ocean discharge of produced water during production of oil and gas has been a long-term 

environmental concern in most offshore oil and gas development areas in the world (Neff, 

2002a). Historically, produced water from onshore and offshore production wells has not been 

discharged to the Alaskan Beaufort Sea. Most is treated and reinjected, primarily for water-flood 

to enhance production of oil. Therefore, produced water is not a source of contaminants, 

particularly PAH, to the Beaufort Sea. 

4.3 21BSources of Sediments, Metals, and Hydrocarbons in the Beaufort Sea 

4.3.1 85BSediments 

Alaskan Arctic rivers typically transport 30 to 80% of their total annual discharge of water and 

>80% of their load of suspended sediments during spring (Rember and Trefry, 2004). During 

the 2 to 3 weeks of the spring floods, usually in late May and early June, about 60% of the 

annual water flow from the Kuparuk River and about one third of the annual flow of the 

Sagavanirktok River are carried to the Beaufort Sea (Trefry et al., 2004a). Peak flows, lasting 

three to about 12 days, range from about 300 m3

/sec in the Sagavanirktok River to about 8,500 

m3/sec in the Colville River (Table 4-2). The total annual river flow from the three rivers is about 

22.7 km3

 (a km3 is equivalent to one billion m3). 

Table 4-2. Rate of discharge of water and total solids from the three largest North Slope rivers 

and from coastal erosion into the development area of the central Alaskan Beaufort Sea. 

Peak flow and sediment discharge, representing 30 to 90% of the total annual discharge, 

occurs during 3 to 12 days in late May and early June each year. Data from Rember and 

Trefry (2004), Trefry et al. (2004), and Alkire and Trefry (2006). 

River/Drainage River Flow Total Solids (Metric 

Peak Range (m Tons/Year) 3/sec) Annual Rate (km3/year) 

Sagavanirktok River 300 - 1200 ~6.5 330,000 

Kuparuk River 500 - 3500 ~1.2 21,000 

Colville River ~8500 ~15 ~5,000,000 

Coastal Erosion --- --- ~1,000,000 

Total --- ~22.7 ~6,350,000 

These three rivers also deliver about 6.35 million metric tons/year of suspended sediments to the 

coastal Beaufort Sea (Table 4-2). An additional 1 million tons/year of suspended sediments is 

from coastal erosion. By comparison, as discussed above, the total volume of drilling mud and 
257 

cuttings discharged to the Beaufort Sea during drilling of about 50 exploratory wells in the 1980s 

and 1990s was about 75,000 m3

 (0.000075 km3) and the total mass of solids discharged was 

about 30,000 metric tons, about 0.00003% and 0.5%, respectively, of the solids discharged from 

the three rivers each year. 

Sedimentation rates in the development area of the nearshore Beaufort Sea range from ~0.04 

cm/yr to ~0.10 cm/yr, with several areas having little or no net accumulation of sediment during 

at least the past 50 years (Trefry et al., 2003, 2004a). Most of the area is considered erosional, 

with fluxes of suspended sediments from rivers and from offshore on the shelf being 

redistributed by storms during the open water seasons, as indicated by increases in 

concentrations of TSS and turbidity during high wind conditions in the open-water period. 

The Sagavanirktok River, the major river carrying sediment into Stefansson Sound, is estimated 

to have an annual sediment load of about 330,000 metric tons (Table 4-2). The depositional area 

for this sediment in the coastal Beaufort Sea is about 1,000 km2 (the approximate area bounded 

by the mainland to the south, the outer islands such as Cross Island to the north, and between 

147.0° N and 148.5° W), yielding an estimated deposition rate of ~0.04 cm/year. 

4.3.2 86BMetals 

The river discharges also delivered large amounts of particulate organic carbon (POC), dissolved 

organic carbon (DOC), and dissolved and particulate metals to the coastal Beaufort Sea 

(Table 3-3 and 4-3). The 116,000 tons/year of POC and high concentrations of DOC (2 to 16 

mg/L) play an important role in complexing with and transporting metals and hydrocarbons in 

the Beaufort Sea (Trefry et al., 2004a,b, 2009). There is some evidence that metals and 

hydrocarbons associated with POC and DOC are less bioavailable and toxic to marine organisms 

than dissolved metals and hydrocarbons (Neff, 2010). The particulate metals discharged from the 

three rivers in the largest amounts, Al, Ba, Ca, Fe, and Zn,, also are present in solution in river 

water (Tables 3-7 and 3-8) and Beaufort Sea water (Table 3-11), and are abundant in drilling 

muds (Table 4-1), river suspended sediments (Table 3-2), and Beaufort Sea Sediments (3-20). A 

regression of each metal versus aluminum concentrations in Beaufort Sea sediments yielded a 

good correlation for most samples, indicating that most metals in the sediments were associated 

with the clay (aluminosilicate) fraction. More than 85% of river sediments plotted along the 

metal/aluminum regressions for offshore sediments, supporting the hypothesis that most of the 

metals in offshore sediments were from the river suspended particles. 

If the Tern Island drilling muds (Table 4-1) are considered representative of the drilling 

muds/cuttings discharged to the Beaufort Sea in the 1980s, then approximately 4.5 metric tons of 

barium and 0.002 metric tons of zinc were discharged to the Beaufort Sea with the 30,000 metric 

tons of drilling solids discharged from 50 exploratory wells. These masses represent 0.09% of 

the barium and 0.0003% of the zinc discharged in particulate matter to the Beaufort Sea each 

year in river discharges. Thus, river discharges are a major source of fresh water, total suspended 

solids, POC, DOC, and dissolved and particulate metals to the coastal Beaufort, and are a much 

larger source than discharges from all the drilling waste discharged to the Beaufort Sea in the last 

three decades. 
258 

4.3.3 87BHydrocarbons 

The PAH, SHC, and StTr profiles of typical river sediment samples indicate a mixed petrogenic, 

pyrogenic, and biogenic source (-23).Total PAH concentrations in river and shore peat ranged 

from 13 to 740 ng/g dry wt (parts per billion) (Table 3-13). As expected, total SHC 

concentrations in the peat were much higher, ranging from 8700 to 260,000 ng/g. Most peat 

samples contained comparatively low concentrations of total StTr; highest concentrations were 

in Kuparuk River sediments, probably because the Kuparuk River drains primarily Arctic tundra 

soils. There were no clear relationships among concentrations of PAH, SHC, StTr, and TOC in 

the Arctic peat. However, the high relative concentrations of PAH and SHC in peat, indicates 

that peat probably is a major source of hydrocarbons in river sediments delivered to the Beaufort 

Sea. 

The SHC, PAH, and StTr profiles of Northstar crude oil (Figure 3-25) were quite different from 

those of river sediments (Figure 3-23) and river peat (Figure 3-24). Profiles of the SHC and PAH 

assemblages in the river sediment and peat samples was similar to that in surficial sediments, 

indicating a common PAH source relationship between the river sediments and the nearshore 

surficial sediments. Perylene, a biogenic PAH, dominates the overall PAH distribution as one of 

the most abundant individual PAHs in many offshore and river sediment samples. Perylene is 

found at equal or greater relative abundance in the river sediments and peat (Figures 3-24 and 3-

25), which suggests the relationship of the rivers as a source of the hydrocarbons in the nearshore 

sediments. Perylene was absent from Northstar crude oil. There was no indication of Northstar 

crude oil PAH and SHC in Beaufort Sea sediments, even those near the Northstar production 

facility. 

Steinhauer and Boehm (1992), Yunker et al., (1991, 1996), Naidu et al. (2003, 2006), Yunker 

and MacDonald (1995), and Elmquist et al. (2008) have concluded, based on the abundance of 

perylene in sediments from sites with and without a past history of exploratory drilling, that most 

of the PAH in Beaufort Sea, Barents Sea, and other Arctic sediments, including those from drill 

sites, comes from erosion of peat, coal, and black carbon deposits along the coast or into rivers 

emptying into the Arctic Ocean. PAH in sediments from the Norwegian and Russian regions of 

the Barents Sea also have been derived in part from eroding natural deposits of kerogens, oil 

shales, and coals (Dahle et al., 2003; Elmquist et al., 2008; Boitsov et al., 2009). A major source 

of PAH in marine sediments throughout the Arctic is diagenesis (early degradation/fossilization 

of plant material) to form peat, kerogens, immature bitumen, and lignitic coals (Yunker and 

MacDonald, 1995; Yunker et al., 1996; Steinhauer and Boehm, 1992; Naidu et al., 2006; 

Elmquist et al., 2008; Boitsov et al., 2009). These PAH-rich materials reach the Arctic Ocean in 

coastal erosion and river runoff. These tightly bound PAH have a low bioavailability and, 

therefore, are not toxic to marine plants and animals (Rust et al., 2004; Neff et al., 2005). 

There also is a large flux of POC and DOC into the Alaskan and Canadian Beaufort Sea and 

Barents Sea from rivers (Trefry et al., 2004b, 2009; Yunker et al., 2005; Elmquist et al., 2008; 

Holmes et al., 2008; Magan et al., 2010). Much of the terrigenous organic matter is delivered to 

the Beaufort Sea in outflows from large Arctic rivers and from coastal erosion and often is 

enriched in metals and hydrocarbons. 
259 

4.4 2BMetals and Hydrocarbons in Beaufort Sea Water, Sediments, and Marine 

Animals 

4.4.1 8BMetals 

Concentrations of dissolved trace metals in coastal Beaufort Sea seawater were highly variable 

(Table 3-11). Concentrations of dissolved As, Cr, and Pb were lower than reported values for 

surface seawater worldwide. Lower As concentrations were found because dissolved As 

concentrations increase with increasing salinity and the salinity of nearshore water is lower than 

that of ocean water due to river runoff of freshwater containing low As concentrations. In 

contrast, concentrations of dissolved Cd, Cu, and Zn were higher than in typical surface 

seawater. Concentrations of dissolved Cd, at 14 to 18 ng/L, in rivers were lower than in seawater 

at any time of year. Concentrations of dissolved Ba were similar to those in typical surface 

seawater, except during 2000 and 2001, when more nearshore samples were collected. Dissolved 

Ba concentrations usually were lower in seawater (10 to 32 μg/L), than in river water because of 

precipitation of barium as barite during mixing of river water with seawater containing naturally 

high concentrations of sulfate. 

Concentrations of particulate metals in the open-waters of the Beaufort Sea were variable as a 

function of the organic matter and clay content in the TSS and POC particles. The area-wide 

averages for 2000, 2001, 2002, 2004, 2005 and 2006 in Table 3-10 show some interannual 

variability; however, most of the variations are due to differences in the composition of the 

suspended sediments as shown by variations in concentrations of Al and Fe and generally 

comparable shifts in concentrations of trace metals. 

Concentrations of metals in Beaufort Sea sediments were highly variable on both spatial and 

temporal scales. The variability was due partly to variations in % silt+clay, and concentrations in 

sediment of total organic carbon (TOC), aluminum, and iron (Table 3-19). Normalization of 

sediment metals concentrations to aluminum concentration reduced the variability and indicated 

that most metals in most sediments were associated with the clay (aluminosilicate) fraction. 

There were no large interannual variations in concentrations of any Al-normalized metals in 

Beaufort Sea sediments (Tables 3-20 and 3-21). With few exceptions, metals concentrations 

measured in cANIMIDA in Beaufort Sea sediments were similar to concentrations measured by 

others in sediments from throughout the Beaufort Sea (Table 22 and 23), but lower than 

concentrations in drilling muds and cuttings discharged during exploratory drilling in 1979 

through 1982 (Tables 3-22, 3-3, 4-1). 

Concentrations of 13 to 18 metals in tissues of several species of fish, amphipods, isopods, and 

clams collected near the Northstar Development, in the Liberty Prospect area, and in reference 

stations in the BSMP areas were similar in 2000 through 2006 (Table 3-25), and comparable to 

metals concentrations in the same or similar species collected in uncontaminated water 

throughout the world (Table 3-26). 

Benthic amphipods and clams were collected at some of the same stations where surface 

sediments were collected between 1999 and 2006 (Table 2-1). Therefore, it is possible to 

determine if there is a significant relationship between metals and hydrocarbons concentrations 

in co-occurring sediments and benthic amphipods and clams in the development area of the 

Beaufort Sea. This cannot be done for fish, because sediments were not collected at most fish 
260 

sampling locations and fish are highly migratory, making it unlikely that there would be such a 

relationship. 

The two most abundant metals (relative to their concentrations in clean marine sediments) in 

historic Beaufort Sea drilling muds (Table 4-1) are barium and chromium. Concentrations of 

these two metals were relatively high in Beaufort Sea sediments, but low in tissues of amphipods 

and clams (Figure 4-1). There was no relationship between concentrations of these two metals in 

sediments and concentrations in tissues of amphipods and clams collected concurrently from the 

same sediments between 1999 and 2006. R2 values were less than 0.01 in all cases, indicating 

that barium and chromium concentrations in tissues were relatively constant over a wide range of 

barium and chromium concentrations in sediments. Concentrations of both metals in the tissues 

of both species were about one-tenth those in sediments in which they were residing. There was 

a single outlier (unexpectedly high metal concentrations) for both metals in both species of 

benthic invertebrates. The outliers were collected in 2002 and 2006 off the mouths of the three 

rivers. The amphipods containing elevated concentrations of chromium were collected in 2002 

near the Northstar facility (station N03). 

Figure 4-1. Regressions of barium and chromium concentrations in sediments and tissues of 

amphipods (A, C) and clams (B, D) collected at several stations in the Northstar, 

Liberty, and BSMP areas of the Beaufort Sea between 1999 and 2006. Approximately 

40 sediment/amphipod and 25 sediment/clam concentration pairs were available 

(Table 2-1). Concentrations in sediments, amphipods, and clams are 

mg/kg dry wt (parts per million). 

R2 = 0.0246

0

10

20

30

40

50

60

100 200 300 400 500 600 700

Barium in Amphipods (mg/kg)

Barium in Sediments (mg/kg)

A

R2 = 0.0158

0

10

20

30

40

50

60

0 100 200 300 400 500 600 700

Barium in Clams (mg/kg)

Barium in Sediments (mg/kg)

B

R2 = 0.0108

0

2

4

6

8

10

12

14

16

18

20

10 20 30 40 50 60 70 80 90 100

Chromium in Amphipods (mg/kg)

Chromium in Sediment (mg/kg)

C

R2 = 0.0005

0

20

40

60

80

100

120

10 20 30 40 50 60 70 80

Chromium in Clams (mg/kg)

Chromium in Sediment (mg/kg)

D
261 

Concentrations of Ba, the best indicator of previous drilling water discharges, in surface 

sediments in the development area ranged from 16 mg/kg to 910 mg/kg between 2000 and 2006, 

with little difference in sediment Ba concentration in Northstar, Liberty, and BSMP sediments 

(Table 3-20). Thus, there is little evidence, with the exception of elevated Ba concentrations in 

sediment cores from a few locations, of past drilling discharges in the development area. 

There were similar results for lead and zinc, also sometimes present at high concentrations in 

drilling discharges (Table 4-1). There was a slightly negative slope to the sediment/tissue 

concentration regressions for both metals and both species (Figure 4-2). However, the highest R2

was only 0.18 (for zinc in clams), indicating that the relationships were not statistically 

significant. Both lead (a non-essential trace metal) and zinc (an essential trace metal) 

concentrations were relatively constant in tissues of both amphipods and clams over a wide range 

of lead and zinc concentrations in sediments. With only a few exceptions, lead concentrations in 

amphipods and clams were below 1.0 mg/kg over a sediment lead concentration range of about 

3.0 to 16 mg/kg. Zinc concentrations in amphipods were about 100 mg/kg in sediments 

containing 10 to 120 mg/kg zinc. Zinc concentrations in most clams ranged from 60 to 90 mg/kg 

in sediments containing 30 to 85 mg/kg zinc. Again, there are single outliers for both metals and 

both species of marine invertebrates. Concentrations of both lead and zinc were elevated in 

amphipods collected in 2004 south of the Northstar facility (station N11). Clams collected in 

2002 from off the mouth of the Kuparuk River (station 5F) and in the center of the liberty 

prospect (L08) contained elevated concentrations of lead and zinc, respectively. 

Two of the metals of concern in the Beaufort Sea ecosystem, because of their potential to 

accumulate to potentially toxic concentrations n the Beaufort Sea food web, are arsenic and 

mercury. Regressions of concentrations of these two metals in sediments and benthic 

invertebrates were not significant (R2

 ranging from 0.001 for mercury in clams to 0.05 for 

arsenic in amphipods) (Figure 4-3). Arsenic concentrations were extremely variable in 

sediments, amphipods, and clams collected between 1999 and 2006 throughout the development 

area. Unlike all the other metals examined, concentrations of both arsenic and mercury in 

invertebrate tissues were not related to those in the sediments where they reside. Much of the 

arsenic in benthic invertebrates is in the form of arseno-sugars and arsenobetaine, probably 

converted from arsenate by microbes in suboxic sediments (Neff, 1997). These organo-arsenic 

compounds are highly bioaccumulative, but not toxic. More than 90% of the mercury in Beaufort 

Sea sediments is inorganic mercuric mercury (Semmler, 2006; Trefry et al., 2009), which is less 

bioaccumulative and toxic than methylmercury (Neff, 2002b). However, the lack of correlation 

between concentrations arsenic and mercury in sediments and tissues indicates that these metals 

probably are not being bioaccumulated from sediments. 
262 

Figure 4-2. Regressions of lead and zinc concentrations in sediments and tissues of amphipods 

(A, C) and clams (B, D) collected at several stations in the Northstar, Liberty, and 

BSMP areas of the Beaufort Sea between 1999 and 2006. Approximately 40 

sediment/amphipod and 25 sediment/clam concentration pairs were available 

(Table 2-1). Concentrations in sediments, amphipods, and clams are 

mg/kg dry wt (parts per million). 

. 

The concentrations of all six metals discussed here are at concentrations in sediments, 

amphipods, and clams at concentrations similar to those in sediments and marine invertebrates 

from uncontaminated marine environments, worldwide (Neff, 2002a) and are well below 

concentrations that might be toxic to the benthic invertebrates or their consumers. 

 

 

R2 = 0.0201

0

1

2

3

4

5

2 4 6 8 10 12 14 16 18 20

Lead in Amphipods (mg/kg)

Lead in Sediment (mg/kg)

A

R2 = 0.031

0.0

0.5

1.0

1.5

2.0

2.5

4 6 8 10 12 14 16

Lead in Clams (mg/kg)

Lead in Sediment (mg/kg)

B

R2 = 0.0238

0

50

100

150

200

250

0 20 40 60 80 100 120

Zinc in Amphipods (mg/kg)

Zinc in Sediment (mg/kg)

C

R2 = 0.1833

50

60

70

80

90

100

110

20 30 40 50 60 70 80 90

Zinc in Clams (mg/kg)

Zinc in Sediment (mg/Kg)

D
263 

Figure 4-3. Regressions of arsenic and mercury concentrations in sediments and tissues of 

amphipods (A, C) and clams (B, D) collected at several stations in the Northstar, 

Liberty, and BSMP areas of the Beaufort Sea between 1999 and 2006. Approximately 

40 sediment/amphipod and 25 sediment/clam concentration pairs were available 

(Table 2-1). Concentrations in sediments, amphipods, and clams are 

mg/kg dry wt (parts per million). 

4.4.2 89BHydrocarbons 

Whole water samples from the three areas of the Beaufort Sea contained 37 to 69 ng/L (parts per 

trillion) TPAH (Table 3-14). Most of the PAH in whole water were associated with the 

particulate fraction. Concentrations of dissolved PAH ranged from 13 to 19 ng/L. The low 

molecular weight 2- and 3-ring PAH were much more abundant than the higher molecular 

weight 4- through 6-ring PAH in both the particulate and dissolved fractions, indicating that 

much of the PAH in surface waters were from a petrogenic origin. If the blank concentrations are 

considered, the actual TPAH concentrations in whole water and the particulate and dissolved 

fractions, ~15 - 40 ng/L, ~11 - 45 ng/L, and ~<1 - 6 ng/L, respectively, are in the range 

frequently reported for uncontaminated nearshore surface seawater (Neff, 2002a). 

 

R2 = 0.052

2

4

6

8

10

12

14

16

18

4 6 8 10 12 14 16 18

Arsenic in Amphipods (mg/kg)

Arsenic in Sediment (mg/kg)

A

R2 = 0.0431

6

8

10

12

14

16

18

6 7 8 9 10 11 12 13 14

Arsenic in Clams (mg/kg)

Arsenic in Sediment (mg/kg)

B

R2 = 0.0284

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Mercury in Amphipods (mg/kg)

Mercury in Sediment (mg/kg)

C

R2 = 0.0014

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Mercury in Clams (mg/kg)

Mercury in Sediment (mg/kg)

D
264 

Concentrations of TPAH in surficial sediments collected between 2000 and 2006 from the 

Northstar, Liberty, and BSMP areas ranged from 0.01 to 1.80 mg/kg (Table 3-24). Much of the 

PAH appeared to be associated with POC in the silt+clay fraction of the sediments. Although 

mean TPAH concentrations increased in sediments from Northstar stations between 2000 and 

2006, the mean TPAH concentrations in sediments collected between 2000 and 2006 combined 

from the three survey areas were similar. The PAH composition did not change between 2000 

and 2006 in Northstar sediments, indicating that the sediment PAH probably did not come from 

Northstar operations. As discussed above much of the sediment PAH and SHC probably were 

derived from hydrocarbon-rich POC from Arctic rivers. 

TPAH concentrations in tissues of eight species of fish combined were low in all years (Table 3-

38). The fish tissue PAH residue data for 2001 through 2006, as well as the low levels of PAH 

exposure biomarker levels in fish tissues, are consistent with chronic, low-level exposure to PAH 

in water, sediments, and food throughout the study area, with no clear point source of 

bioavailable PAH in the coastal environment. 

The tissue residue data for PAH, SHC, and StTr indicate that hydrocarbons in tissues of nearshore benthic invertebrates from the development area are derived in part from DOC and POC 

entering the Beaufort Sea from nearby rivers, as well as the Mackenzie River, and from coastal 

erosion. Contributions from the development of and oil production from Northstar facility appear 

to be low. 

These conclusions are confirmed by regression analysis of TPAH and TSHC concentrations in 

sediments and tissues of amphipods and clams collected from the same stations between 1999 

and 2006. The regression of TPAH concentrations in sediments versus concentrations in tissues 

of amphipods and clams collected from the same stations shows that there is no relationship 

between TPAH concentrations in sediments and the two benthic invertebrates (R2

 = 0.0004 and 

0.072, respectively) (Figure 4-4a,b). With a few exceptions, TPAH concentrations in amphipods 

are less than 0.1 mg/kg over a range of 0.01 to 1.80 mg/kg TPAH in the sediments where they 

reside. The uniformly low concentrations of TPAH in amphipod tissues indicates that these 

crustaceans are able to metabolize and excrete bioaccumulated PAH, and that the sediment PAH 

have a low bioavailability. 

Concentrations of TPAH in clam tissues was more variable, ranging from about 0.01 mg/kg to 

about 0.15 mg/kg, compared to a concentration range of about 0.05 to 0.75 mg/kg in the 

sediments where the clams reside (Figure 4-4b). The few outlier concentrations were in 

amphipod and clams collected in the Liberty prospect (stations L03 and L04) in 1999 and 2006. 

The lack of correlation between TPAH concentrations in sediments and clams and the limited 

ability of clams to metabolize and excrete bioaccumulated PAH (Neff, 2002a) confirms that 

sediment PAH have a low bioavailability. PAH tightly bound to peat, kerogens, and coal have a 

very low bioavailability and toxicity, as discussed above. 

There also was no relationship between concentrations of TSHC in sediments and tissues of 

amphipods and clams (R2

 = 0.15 and 0.04, respectively) (Figure 4-4c,d). TSHC concentrations 

were highly variable in tissues of amphipods, ranging from 5 mg/kg to 249 mg/kg. 

Concentrations in sediments were much lower, ranging from 0.3 to 38 mg/kg. Most of the SHC 

in amphipods is pristane (Table 3-40), bioaccumulated from consumption of copepods or 
265 

animals that consume large numbers of copepods. Pristane concentrations in Beaufort Sea 

sediments is very low. Thus, the amphipods are not bioaccumulating SHC from sediments. 

 

Figure 4-4. Regressions of total PAH (TPAH) and total SHC (TSHC) concentrations in 

sediments and tissues of amphipods (A, C) and clams (B, D) collected at several 

stations in the Northstar, Liberty, and BSMP areas of the Beaufort Sea between 1999 

and 2006. Approximately 40 sediment/amphipod and 25 sediment/clam concentration 

pairs were available (Table 2-1). Concentrations in sediments, amphipods, and clams 

are mg/kg dry wt (parts per million). 

With a few exceptions, TSHC concentrations in clams were below 20 mg/kg, compared to 

concentrations in sediments ranging from 1.9 to 26 mg/kg (Figure 4-4d). The SHC assemblage in 

clam tissues is dominated by higher molecular weight n-alkanes (>C24), with no obvious 

odd/even carbon number preference. The SHC assemblage in Beaufort Sea sediments also is 

dominated by high molecular weight n-alkanes, with a pronounced odd/even carbon number 

preference, indicating that the sediment SHC are derived primarily from terrestrial plant material. 

The SHC assemblage in petroleum usually is dominated by low molecular weight alkanes. Thus, 

the SHC in clams probably are from marine and terrestrial biological sources. 

R2 = 0.0004

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00

TPAH in Amphipods (mg/kg)

TPAH in Sediment (mg/kg)

A

R2 = 0.0719

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

TPAH in Clams (mg/kg)

TPAH in Sediment (mg/kg)

B

R2 = 0.148

0

50

100

150

200

250

300

0 5 10 15 20 25 30 35 40

TSHC in Amphipods (mg/kg)

TSHC in Sediment (mg/kg)

C

R2 = 0.0441

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25 30

TSHC in Clams (mg/kg)

TSHC in Sediment (mg/kg)

D
266 

4.5 23BAre Chemicals from Offshore Oil Operations Entering the Beaufort Sea Food 

Web? 

The Beaufort Sea food web is a relatively simple one with relatively few abundant taxa at each 

trophic level (Figures 3-54 and 3-55). Nutrients to support primary production in the Alaskan 

Beaufort Sea are derived primarily from inflows from the Bering Sea, Anadyr Water (from the 

Russian Chukchi Sea), the Canadian Beaufort Sea, and upwelling from the Arctic Basin (Dunton 

et al., 2003, 2004). However, DOC concentrations are high in the spring floods from the 

Sagavanirktok, Kuparuk, and Colville Rivers (Trefry et al., 2004b, 2009; Holmes et al., 2008). 

About 20 to 40% of the DOC in the spring freshet is labile and is an important source of nutrient 

input to the Beaufort Sea (Holmes et al., 2008). Primary production, supported by these nutrient 

sources, is pelagic (phytoplankton), epontic (living on the underside of sea ice), and benthic 

(Dunton et al., 2009). The nutrient inputs from Arctic rivers during the spring breakup may 

stimulate the spring phytoplankton blooms. The epontic community along the seasonal ice edge 

may contribute substantially to overall pelagic production. Epontic microalgae support diverse 

communities of ice-associated meiofauna that help support spring zooplankton blooms (Carey 

and Montagna, 1982). 

As discussed above, most of the hydrocarbons in river water, particularly during the spring 

floods, are associated with POC and DOC, whereas most of the metals are associated with 

suspended fine-grained sediments. These complexed metals and hydrocarbons accumulate in 

offshore sediments. Metals and hydrocarbons from offshore oil and gas operations, such as 

gravel island construction and drilling waste discharges, also tend to accumulate in Beaufort Sea 

sediments. The POC in the Arctic rivers is derived primarily from terrestrial plant matter and 

peat and is quite refractory (Magan et al., 2010). Metals and hydrocarbons adsorbed to terrestrial 

POC from the Arctic rivers in sediments from the development have a low bioavailability and 

toxicity to benthic and pelagic marine animals. Metals and hydrocarbons in tissues of benthic 

invertebrates and fish from the Beaufort Sea are at background levels similar to concentrations in 

tissues of the same or related species from clean marine environments throughout the world. 

The metals and hydrocarbons associated with offshore oil and gas operations also have a limited 

bioavailability (Neff, 2005, 2010); a small fraction may be bioaccumulated by marine plants and 

animals and transferred through marine food webs. None of these chemicals, except possibly 

arsenic and mercury, biomagnifies in marine food webs. Their concentrations decrease with each 

trophic step. 

Arsenic does seem to biomagnify in some steps of marine food webs because inorganic arsenic is 

converted to arseno-sugars and arsenobetaine, probably by sediment bacteria. These organoarsenic compounds are much more bioavailable and slower to be released from tissues than 

inorganic arsenate and arsenite salts, so arsenobetaine, in particular, tends to bioaccumulate to 

high concentrations in marine animals that consume benthic fauna (Neff, 1997). Arsenobetaine is 

not toxic to consumers, including man. Arsenic tends to biomagnify to only a limited extent in 

the Beaufort Sea food web (Semmler, 2006). Arsenic concentrations are relatively high in ocean 

waters of the Beaufort Sea and probably is derived from upwelling of slope water onto the shelf 

(Trefry et al., 2009). Arsenic is present at expected concentrations in the Beaufort Sea food web. 

There is no evidence of bioaccumulation of arsenic from offshore oil and gas operations. 
267 

Methylmercury, but not inorganic mercury, tends to biomagnify in the Beaufort Sea food web. 

Because methylmercury tends to biomagnify in marine food webs, concentrations of total and 

methylmercury are high in high trophic level consumers in Arctic seas. Concentrations of total 

and methylmercury are high in liver and muscle tissues of several marine mammals collected off 

Barrow, AK (Table 3-18). Fish- and mammal-eating marine carnivores, such as polar bears, 

beluga whales, and some seals, contain high concentrations of total and methylmercury in liver, 

with lower concentrations in muscle and other organs. Bowhead whales do not bioaccumulate 

high concentrations of mercury because they feed at a lower trophic level on large copepods and 

euphausiids that contain low concentrations of methylmercury. Drilling discharges contain low 

concentrations of mercury that is tightly bound in insoluble forms in the drilling mud barite 

(Neff, 2002b). This insoluble mercury can not readily be converted to bioaccumulative, toxic 

methylmercury, so drilling discharges do not introduce bioavailable mercury into the Beaufort 

Sea food web. 

As discussed above, concentrations of hydrocarbons, including toxic PAH, are low in Beaufort 

Sea water, sediments, and tissues of marine animals. There are no data on concentrations of PAH 

in top consumers in the Beaufort Sea food web. Beluga whales from off the Mackenzie River 

delta exhibited high levels of induction of the PAH exposure biomarker CYP1A, indicating 

exposure to relatively high concentrations of PAH or other inducers, such as halogenated 

aromatic hydrocarbons (Wilson et al., 2005). The PAH and halogenated aromatic compounds 

probably came from the river drainage that includes the vast heavy oil reserves in central 

Alberta. However, PAH concentrations are low in water, sediments, and marine animals from the 

Alaskan Beaufort Sea and marine mammals and birds are able to rapidly metabolize and excrete 

bioaccumulated PAH. Therefore, PAH concentrations in tissues of upper trophic level marine 

animals in the Beaufort Sea food web are expected to be low. There is no evidence of input of 

large amounts of PAH from offshore oil and gas operations into the Beaufort Sea; concentrations 

are at expected levels in water, sediments, and tissues of marine invertebrates and fish. 

4.6 24BIs There Evidence of Physical, Chemical, or Biological Changes Caused by 

Construction and Production at Northstar? 

Monitoring during ANIMIDA with vertical profiles and horizontal tows showed that there were 

no significant differences in turbidity or concentrations of TSS in proximity (within 100 to 500 

m) of Northstar Island relative to other locations in the ANIMIDA study area (Trefry et al., 

2004a,b). Variations in turbidity and TSS concentrations in the water column during the open 

water season are due largely to variations in wind speed and duration (Table 4-3). Arctic rivers 

also discharge massive amounts of TSS both onto and under the shorefast ice during the spring 

floods (Table 4-4). Some of this TSS persists well into the open water season and is repeatedly 

resuspended by summer storms. 

Concentrations of dissolved and particulate metals were not significantly different in the water 

column of Northstar area than in the overall cANIMIDA study area. A few water samples 

collected near Northstar contained slightly elevated concentrations, compared to other parts of 

the development area, of particulate lead and cadmium, probably associated with plankton 

detritus, which sometimes contains elevated concentrations of some metals derived from 
268 

Table 4-3. Relationship between wind speed and total suspended solids (TSS) concentrations in 

surface waters of the Beaufort Sea development area during the open water speed. Underice TSS concentration range is included for comparison. From Trefry et al., 2004). 

Wind Speed (Knots) TSS Concentration (mg/L) 

Calm to 5 ~1 - 4 

5 - 10 3 - 8 

10 to 20 5 to 15 

> 20 50 - >100 

Under Ice <0.1 - 0.5 

Table 4-4. Estimated masses of suspended sediment (TSS), particulate metals and particulate 

organic carbon (POC) carried by the Sagavanirktok, Kuparuk, and Colville Rivers to the 

coastal Beaufort Sea. Masses are metric tons/year. Estimates for the Sagavanirktok and 

Kuparuk Rivers are based on 2001 data collected by Trefry et al. (2004) and for the 

Colville River are from Arnborg et al. (1967). From Trefry et al. (2004). 

Parameter Sagavanirktok River Kuparuk River Colville River Total Discharge 

TSS 330,000 21,000 5,000,000 5,350,000 

POC 5000 1000 110,000 116,000 

Arsenic (As) 3.5 0.3 70 73.8 

Barium (Ba) 241 12 4900 5153 

Copper (Cu) 11 0.7 200 212 

Iron (Fe) 11 0.7 250 267 

Lead (Pb) 6 0.3 120 126 

Zinc (Zn) 41 2.4 650 693 

upwelling of slope water onto the shelf. Concentrations of all dissolved metals were in the range 

of background values, which are well below the EPA water quality criteria for chronic effects in 

marine organisms (Table 3-11). 

The TPAH concentrations and PAH compositions were similar in the dissolved and particulate 

phases of water samples collected in 2000 and 2002 near the Northstar production island, in the 

Liberty prospect, and at historic BSMP stations (Table 3-14). Much of the dissolved and 

particulate PAH in the development area were from the Arctic rivers (Yunker et al., 1991, 1996; 

Yunker and MacDonald, 1995; Steinhauer and Boehm, 1992; Trefry et al., 2003, 2004a,b, 2009; 

Rember and Trefry, 2004). Concentrations of dissolved and particulate TPAH were low at all 

locations and within the range reported by others for nearshore marine waters world-wide (Neff, 

2002a). 

Inter-annual shifts in the texture of surficial sediment were observed throughout the cANIMIDA 

study area between 1999 and 2006 (Brown et al., 2010). During 1999, surficial sediment from 

several stations near Northstar was composed almost exclusively of sand and gravel. Most 

surficial sediments collected from the same stations in 2000 contained more than 50% silt+clay. 

Although the exact mechanism for this shift is not known, the 1999 samples were collected after 
269 

a 6-day storm with winds in excess of 25 knots that may have eroded away finer-grained 

material. No such storms preceded collection of the 2000 samples that probably contained finegrained sediments discharged from the Kuparuk River during the spring breakup of 2000. Fine 

grained sediments were more abundant in sediments collected in 1999 at a few stations close to 

Northstar than in sediments collected at the same locations in 2000. This shift may have resulted 

from inputs of coarser material at these stations in association with construction of the Northstar 

gravel island. There continued to be shifts in grain sized distributions at all stations in the 

Northstar area between 2000 and 2006. These shifts were associated with inter-annual variations 

in the concentrations of TSS in the spring river flood from the Kuparuk, Sagavanirktok, and 

Colville Rivers (Table 3-1). Thus, the Northstar area appears have a dynamic sedimentary 

environment, an observation that is consistent with difficulties in finding sediment cores with a 

useful radioisotope record of sediment geochronology. 

Concentrations of 11 metals, of the types that are of concern in marine sediments because of 

their toxicity or association with offshore oil and gas development activities (Neff, 2010), were 

similar in surface sediments in the Northstar, Liberty, and BSMP areas in 2000 through 2006 

(Tables 3-19, 3-20, and 3-21). None of the metals was consistently present at a higher range of 

concentrations in sediments from the Northstar production facility, than in sediments from the 

Liberty prospect or the historic BSMP stations. 

Statistical analyses of TPAH, TSHC, and StTr concentrations in surface sediments collected 

throughout the development area between 1999 and 2006 indicated that hydrocarbon 

concentrations increased significantly at in post-1999 sediments from the Northstar area. 

However, a closer examination of the PAH data show that although PAH concentrations in 

Northstar sediments increased after construction (2000, 2002, and 2004 - 2006 combined), the 

distribution and composition of the PAH assemblage in sediments remained relatively 

unchanged. The composition of the sediment hydrocarbons in Northstar sediments is best 

summarized by a comparison of the pyrogenic to petrogenic PAH ratios in sediments from 1999, 

2000, 2002 and 2004 - 2006. The pyrogenic/petrogenic ratio is the same in sediments collected 

at Northstar in 1999 and 2000, but then increases after 2000 (Figure 3-37), indicating that there 

were no incremental additions of petrogenic hydrocarbons to Northstar sediments from 

construction activities in the winter of 1999/2000. Some of the pyrogenic PAH may have come 

from flaring of waste gases on the production island during the early years of production. 

Apparently, the Northstar surface sediments were depleted in hydrocarbons in 1999, possibly by 

storm-driven bed transport of hydrocarbon-rich POC from the sediments. The organic analyses 

and resulting statistical comparisons of the 1999, 2000, 2002, and 2004 Northstar, BSMP and 

Liberty data, support this explanation. The hydrocarbon concentration and composition data do 

not reveal any detectable hydrocarbon input that can be attributed to the Northstar operations, 

when viewed against the pre-construction levels in the sediments and the pre-construction 

hydrocarbon composition and regional distribution. 

Diagnostic ratio plots of sterane and triterpane petroleum biomarkers show that the hydrocarbon 

composition in sediment cores fall well within the range defined by hydrocarbon data for the 

surface sediment samples from the area (Figure 3-43). This provides further evidence that the 

sediment core data are representative of the regional hydrocarbon background, and do not 

indicate any substantial influence from anthropogenic hydrocarbon inputs from construction and 
270 

production in the Northstar or Prudhoe Bay areas, as indicated by the distance on the plot 

between the data points for Northstar and North Slope crude oils and the sediment cores. 

TPAH and SHC concentrations were not higher in marine animals collected near the Northstar 

facility in 1999 through 2006 than in marine animals from other areas of the Beaufort Sea, 

indicating that the offshore operations were not a significant source of PAH in the animal tissues. 

All concentrations in marine animals tissues were well below concentrations that are considered 

hazardous to the marine animals or their consumers, including man (Neff et al., 2009). 

4.7 25BPossible Effects of Offshore Oil Development on the Boulder Patch Ecosystem 

and Subsistence Whaling Near Cross Island 

Offshore oil exploration and development in the Beaufort Sea could affect the Boulder Patch and 

areas northeast of Cross Island where the annual subsistence whale hunt takes place by changing 

(increasing) concentrations of suspended sediment, POC, and biodegradable DOC in the 

nearshore water column. Physical disturbance by vessel activity in the Boulder Patch or in areas 

along the coast where bowhead migrate westward each fall is perhaps the greatest threat to these 

biological resources. Construction and production operations offshore on artificial gravel islands 

could cause or contribute to increases in concentrations of TSS (and associated turbidity), POC, 

DOC, metals, and hydrocarbons in the water column, and tainting of the Beaufort Sea food web 

with potentially toxic chemicals. 

TSS concentrations were much lower in the water column of the Boulder patch during the 

summers of 2004 and 2006 than in 2005 but the general trend of decreasing TSS with distance 

offshore was observed in all three years (Dunton et al., 2009) (Figure 3-57). Concentrations of 

the primary nutrients, ammonium, phosphate, silicate, and nitrate + nitrite nutrient also were 

higher in 2005 than in 2004 and 2006 (Table 3-48). Dissolved oxygen concentrations were at or 

above saturation in all years monitored, though concentration were slightly higher in 2004 than 

in 2005 and 2006, probably due to small differences in temperature and salinity among the three 

years. 

Underwater light intensity dropped to near zero in the water column of some parts of the Boulder 

Patch during the summer of 2004, due to a series of intense storms. Water transparency was 

highest in 2006, probably due to the absence of significant storm events during the study period. 

These interannual differences in water quality have a significant effect on the macroalgal 

community of the Boulder Patch which receives sufficiently intense solar radiation to support 

growth for only a few summer months each year (Dunton et al., 2009). Blade elongation in the 

kelp Laminaria solidungula displayed large spatial and temporal variability between 1996 and 

2006 (Figure 3-59). Growth was measured per growth year, defined as the period beginning on 

15 November one year and ending on 15 November the following year. Mean site blade growth 

was lower at every site in growth year 2003 compared to growth in all other growth years 

between 2000 and 2006, reflecting the exceptionally poor weather conditions in summer 2003 

that produced extremely low levels of ambient photosynthetically active solar radiation (PAR). 

An interannual comparison of growth years 1998 – 2005 at two Boulder Patch stations indicated 

that linear growth was lowest during growth year 2003, highest in growth year 2000, and that 

2005 was similar to 1998-2000. Changes in local climatology clearly have an important role in 
271 

regulating kelp growth through increased cloud cover and sustained winds that negatively impact 

kelp growth (Figure 3-60). 

There is no evidence that these inter-annual variations in TSS, POC, DOC, and nutrients 

concentrations are caused or altered significantly by offshore oil operations. Much of this 

material comes from the Arctic rivers and most is delivered to the Beaufort Sea during a brief 

period during the spring floods accompanying breakup of the on-shore and offshore ice. 

Concentrations of TSS in the spring flow water from the Sagavanirktok and Kuparuk Rivers in 

2001, 2002, 2004, and 2006 and from the Colville River in 2001 and 2006 were highly variable 

both among years and within each annual spring flood (Table 3-1). Concentrations of POC (as a 

% of TSS) varied by factors of 2 to 5 in each of the rivers between 2001 and 2006, with the 

highest POC concentrations in Kuparuk River suspended sediments (Table 3-2). 

Some links between river inputs of suspended sediments and local offshore TSS concentrations 

and sedimentation rates can be made with available data from the cANIMIDA Project. 

Concentrations of TSS declined sharply with distance offshore from the Sagavanirktok River, 

even during the spring floods. Sedimentation rates are very low throughout the development area 

and most areas are not considered depositional (Trefry et al., 2003). Surficial sediments from 

some sites in the Boulder Patch contain low concentrations of silt+clay, indicating that they 

probably are not depositional (Brown et al., 2010). Low sedimentation rates are important for 

growth, production, and biodiversity of the Boulder Patch. However, large storms can cause 

massive sediment resuspension and bed transport that can harm the macroalgal community. 

River flow and discharge of TSS and POC are much lower during the summer than during the 

brief period of the spring flood. These discharges do not contribute much to offshore 

sedimentation but may contribute to local increases in water turbidity, particularly during 

summer storms and rain. Concentrations of TSS in the Kuparuk River during summers of 2004, 

2005 and 2006 averaged 1.0 mg/L, about 25 to 60 times lower than during the spring floods 

(Table 3-6). Concentrations of TSS in the Sagavanirktok River were more variable during 

summer with a range of 0.5 to 53.4 mg/L (Table 3-5). An increase in TSS concentrations >1-2 

mg/L was typically linked to a rain event that raised flow and TSS (Table 3-5). During 2004, a 

rain storm raised the water flow rate and concentrations of TSS to 53 mg/L in the Sagavanirktok 

River on August 3. This discharge of TSS may have contributed to the low light intensities in the 

Boulder Patch in the summer of 2004. 

At typical concentrations of TSS in summer (~2 mg/L), concentrations of particulate metals and 

organic carbon in the Sagavanirktok River during the summer of 2004 were lower than in spring 

(Table 3-5) but close to results obtained during summer for previous years (Trefry et al., 

2004a,b). After the 2004 rainstorm, the concentrations of particulate metals increased to levels 

that were closer to those for particulate metals in spring 2004, except for Pb (Table 3-5). The rain 

seems to have carried in particles that were slightly more Pb-rich than typically observed, 

perhaps representing a contribution from road runoff or deposition with rain. 

Concentrations of dissolved and particulate metals and hydrocarbons in the open-waters of the 

Beaufort Sea were variable as a function of the organic matter and clay content in the TSS and 

POC particles. The area-wide averages for 2000, 2001, 2002, 2004, 2005 and 2006 in Tables 3-

10 and 3-14 show some interannual variability; however, most of the variations are due to 
272 

differences in the composition of the suspended sediments as shown by variations in 

concentrations of Al and Fe and generally comparable shifts in concentrations of trace metals 

and hydrocarbons. These metals and hydrocarbons may get into the Boulder Patch and be 

bioaccumulated by the local plants and animals. However, all dissolved and particulate metals 

and hydrocarbon concentrations are at background concentrations, well below concentrations 

that could harm the biological communities of the Boulder Patch. 

Concentrations of metals, TPAH, and TSHC in sediments, amphipods, and clams collected in the 

Boulder Patch in 1999 through 2006 were similar to concentrations in sediments, amphipods, 

and clams from elsewhere in the Beaufort Sea and in uncontaminated Arctic marine habitats 

elsewhere in the world. Thus, there is no evidence that the marine biological community of the 

Boulder Patch is being exposed to chemicals from offshore oil operations. 

The success of the annual subsistence bowhead whale hunt is variable from year to year, 

depending mainly on the weather. Seasons may be characterized as “poor weather” years (2003, 

2004, 2005, 2007) or “bad ice” years (2005, 2006) or years when the whales were farther out or 

behaving in a different way making the hunt more difficult (2001 and to some extent 2002) 

(Galginaitis, 2009). The only documented disturbance of the whale hunt was an incident of nonoil-industry vessel traffic in the area where whales were congregating during the fall migration, 

resulting in alterations of whale behavior, making the hunt more difficult. As discussed above, 

bowhead whales contain lower concentrations of most chemical contaminants in their tissues 

than most other marine mammals do. This is due to their lower trophic status, based on a diet 

consisting primarily of large copepods and euphausiids. Thus, there is a very low risk that whales 

are being contaminated with chemicals from offshore oil operations during their spring and fall 

migrations through the development area. 

The abundance of suitably dense patches of zooplankton to support feeding of bowhead whales 

in the area offshore of Cross Island probably is influenced by the amounts of labile DOC and 

POC and primary nutrients being discharged from the Sagavanirktok and Kuparuk Rivers during 

the spring floods. As discussed above, concentrations of the primary nutrients in surface waters 

of the Boulder Patch were higher in 2005 than in 2004 and 2006 (Table 3-48). However, we 

don't know if the higher nutrient concentrations in 2005 stimulated growth of more bowhead 

food, because the 2005 harvest was poor because of bad weather, ice conditions, and interference 

from a motor vessel (Table 3-52). More work is needed to better characterize the relationships 

between nutrients influxes from rivers, primary productivity, and abundance of zooplankton prey 

of bowhead whales off Cross Island and Stefansson Sound. 
273 

5 4BRECOMMENDATIONS 

With the continuing growth in concern about the possible harmful impacts of offshore oil and 

gas operations on the marine environment and the biological resources it supports, particularly in 

the Arctic, there is an urgent need for BOEMRE to continue intensive monitoring of 

environmental effects of offshore oil and gas exploration, development, and production. The 

ANIMIDA/cANIMIDA Project and physical oceanography projects have provided and excellent 

framework for understanding the physical/chemical dynamics of the Beaufort and Chukchi Sea 

continental shelf. This information is critical for predicting potential ecosystem disturbances 

from offshore oil and gas operations in Arctic Alaska. Such studies should continue, but as part 

of a program to better understand the dynamics of the benthic and pelagic ecosystems of the 

Alaskan Beaufort and Chukchi Seas and how physical and chemical disturbances of the types 

associated with offshore oil and gas operations can affect these ecosystems and their biological 

resources, particularly those of importance to the local Inupiat people. 

The following topics could be a component of the BOEMRE environmental assessment program 

for the development area of the Beaufort Sea. 

 ANIMIDA/cANIMIDA has made considerable progress in identifying and characterizing 

the sources of sediments, DOC, POC, metals, and hydrocarbons on the continental shelf 

of the Beaufort Sea. Additional information is needed on: 

o amounts and geochemistry of suspended sediments discharged all along the Alaskan 

and Canadian Beaufort Sea coast from rivers and coastal erosion. 

o sources and concentrations of primary nutrients (e.g., N, PO4) in coastal and offshore 

waters. 

o the chemical characteristics of the different classes of POC and DOC from rivers and 

coastal erosion, how the chemistry differs among the different sources, the 

biodegradability of these organic materials and their contribution of nutrients to the 

pelagic and benthic food webs of the coastal Beaufort Sea. 

o the chemical composition and sources of the POC and DOC in Beaufort Sea 

sediments and possible source apportioning to different terrestrial (e.g., rivers and 

erosion in Alaska and Canada) and marine (e.g., water flows from the Chukchi Sea, 

upwelling from the outer shelf, and biodiverse Arctic communities, such as the 

Boulder Patch). 

o contributions of coastal peat, oil seeps, oil-rich shales, and upriver sources to the 

complex organic fractions in the waters and sediments of the Beaufort Sea. 

o identity unique diagnostic markers of the terrestrial and oceanic sources of the 

Beaufort Sea POC that can be used to help identify the sources of the POC in 

sediments, and rates of ingestion by different members of the pelagic and benthic 

ecosystem. 

This information will be useful for identifying the importance of terrestrial and offshore POC 

and DOC in the Beaufort Sea food web, particularly the contribution of nutrients to pelagic 

primary production, the first step in the pelagic food web leading to copepods that bowhead 

whales consume during their fall migration through the Alaskan Beaufort Sea. 
274 

 Limiting monitoring near past exploratory drilling sites in the Alaskan and Canadian 

Beaufort Sea has identified slightly elevated concentrations of hydrocarbons, particularly 

PAH, and some metals, such as barium, in surface sediments near the former drill sites. 

These hydrocarbons appear to be refractory, having persisted for up to two decades in 

surface sediments, and are not bioavailable to benthic organisms. There is a need to better 

characterize the chemical composition and phase associations of these hydrocarbon 

assemblages. They may be associated with fossil kerogens eroded from the vast fossil 

(~18,000 years old) peat bogs on the North Slope. Full characterization may help identify 

hydrocarbon discharges associated with current and future exploration and production 

activities in the Beaufort Sea. 

 The ANIMIDA/cANIMIDA Project, though well designed and executed, missed part of 

its overall goal, because drilling wastes were not discharged during development of the 

Northstar facility, and Liberty was not developed at all during the project. There are plans 

to perform exploratory drilling in the Beaufort Sea in the next few years, particularly in 

the Camden Bay area. The industry is planning extensive monitoring projects to identify 

effects of drilling and long-term effects of any permitted discharges. BOEMRE should 

consider collaborating in the monitoring programs, providing additional studies not 

currently planned by industry. These studies could focus on region-wide assessment of 

key biological resources, such as zooplankton, marine fish, birds, and marine mammals, 

including bowhead whales. 

 Monitoring of the Cross Island subsistence bowhead whale harvest should continue, 

particularly if plans go ahead for exploratory drilling in Camden Bay. More information 

should be collected, mainly from the whale boat captains and crews, on variations in 

behavior and abundance of whales near shore in different years, and the possible reasons 

for these variations. It would be extremely useful to, if possible, collect the contents of 

the stomachs of harvested whales to determine the extent of feeding off Cross Island and 

the composition of the food. It also would be valuable to collect zooplankton samples in 

the areas off Cross Island where the whales congregate during the fall migration. This 

information would contribute to a better understanding of the importance of terrestrial 

nutrient sources for the zooplankton community. 

 
275 

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APPENDIX A 

ANIMIDA and cANIMIDA REPORTS, PUBLICATIONS, 

AND OTHER PRODUCTS 
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A-1

cANIMIDA DATA MANAGEMENT PLATFORM 

A Web site for the management of and access to the ANIMIDA and cANIMIDA field 

and analytical data, and a repository for the Program reports and other documents. 

http://www.duxbury.battelle.org/CANIMIDA/ 

TECHNICAL REPORTS 

cANIMIDA 

(continuation of Arctic Nearshore Impact Monitoring in Development Area)

 

Task 1

Neff, J. (2010). Continuation of the Arctic Nearshore Impact Monitoring in the 

Development Area (cANIMIDA): Synthesis, 1999-2007. cANIMIDA Task Order 1 Final 

Report. OCS Study BOEMRE 2010-032. Contract No. M03PC00014, Submitted to U.S. 

Department of Interior, Anchorage, AK, December, 2010.

Task 2

Brown, J. (2010). cANIMIDA Task 2. Hydrocarbon and Metal Characterization of 

Sediments in the cANIMIDA Study Area. cANIMIDA Task Order 2 Final Report. Report 

based on 2004-2006 field surveys. OCS Study MMS 2010-004. Contract No. 

M04PC00001, Submitted to U.S. Department of Interior, Anchorage, AK, February, 

2010. 

Brown, J. (2005). cANIMIDA Task 2. Hydrocarbon and Metal Characterization of 

Sediments in the cANIMIDA Study Area. cANIMIDA Task Order 2 Interim Report. 

Report based on summer 2004 field survey. Contract No. 0104-CT-05532, Submitted to 

U.S. Department of Interior, Anchorage, AK. 

Task 3 and 4

Trefry, J.H., Trocine, R.P., Alkire, M.B., Semmler, C.M., Savoie, M., and R.D. Rember 

(2009). cANIMIDA Task 3 and 4: Sources, Concentrations, Composition, and 

Dispersion Pathways for Suspended Sediment and Potential Metal Contaminants in the 

Coastal Beaufort Sea. cANIMIDA Task Order 3 and 4 Final Report. Report based on 

2004-2006 field surveys. OCS Study MMS 2009-014. Contract M04PC00035 and 

M04PC00036. Submitted to U.S. Department of Interior, Anchorage, AK, March, 2009. 

Trefry, J.H., Alkire, M.B., Trocine, R.P. and Savoie, M. (2006). cANIMIDA Task 3: 

Sources, Concentrations, Composition, and Dispersion Pathways for Suspended 

Sediment in the cANIMIDA Study Area, and Task 4: Partitioning of Potential 

Contaminants Between Dissolved and Particulate in the cANIMIDA Study Area. 

cANIMIDA Task Order 3 and 4 Interim Report. Report based on 2004 field surveys. 

Contract No. 0104-CT-32080, Submitted to U.S. Department of Interior, Anchorage, AK. 
A-2

Task 5

Neff, J.M., Trefry, J.H., Durell, G.S. (2009). cANIMIDA Task 5. Integrated 

Biomonitoring and Bioaccumulation of Contaminants in Biota of the cANIMIDA Study 

Area. cANIMIDA Task Order 5 Final Report. Report based on summer 2004-2006 field 

surveys. OCS Study MMS 2009-037. Contract No. M04PC00020, Submitted to U.S. 

Department of Interior, Anchorage, AK, October, 2009. 

Neff, J., Durell, G, and Himmer, T (2006). cANIMIDA Task 5. Integrated 

Biomonitoring and Bioaccumulation of Contaminants in Biota of the cANIMIDA Study 

Area. cANIMIDA Task Order 5 Interim Report. Report based on summer 2004 and 2005 

field surveys. Contract No. 0104-CT-32135, Submitted to U.S. Department of Interior, 

Anchorage, AK. 

Task 6

Dunton, K., Iken, K., Schonberg, S., Funk, D. (2009). cANIMIDA Task 6. Long-Term 

Monitoring of the Kelp Community in the Stefansson Sound Boulder Patch: Detection of 

Change Related to Oil and Gas Development. cANIMIDA Task Order 6 Final Report. 

Report based on summer 2004-2007 field surveys. OCS Study MMS 2009-040. 

Contract No. M04PC00031. Submitted to U.S. Department of Interior, Anchorage, AK, 

July, 2009. 

Dunton, K (2007). cANIMIDA Task 6. Long-Term Monitoring of the Kelp Community 

in the Stefansson Sound Boulder Patch: Detection of Change Related to Oil and Gas 

Development. Report based on summer 2004, 2005, and 2006 field surveys. Submitted 

to U.S. Department of Interior, Anchorage, AK. 

Dunton, K (2006). cANIMIDA Task 6. Long-Term Monitoring of the Kelp Community 

in the Stefansson Sound Boulder Patch: Detection of Change Related to Oil and Gas 

Development. Report based on summer 2004 and 2005 field surveys. Submitted to U.S. 

Department of Interior, Anchorage, AK. 

Task 7

Galginaitis, M. (2009). cANIMIDA Task 7. Annual Assessment of Subsistence 

Whaling Near Cross Island, 2001-2007. cANIMIDA Task Order 7 Final Report. Report 

based on 2001-2007 field surveys. OCS Study MMS 2009-038. Contract No. 0104-CT32149 and M04PC00032. Submitted to U.S. Department of Interior, Anchorage, AK, 

July, 2009. 

Galginaitis, M. (2008). cANIMIDA Task 7. Draft Annual Assessment of Subsistence 

Bowhead Whaling Near Cross Island, 2007. cANIMIDA Task 7 Draft Annual Report. 

Contract No. 0104-CT-32149. Submitted to U.S. Department of Interior, Anchorage, 

AK. 
A-3

Galginaitis, M. (2008). cANIMIDA Task 7. Draft Annual Assessment of Subsistence 

Bowhead Whaling Near Cross Island, 2006. cANIMIDA Task 7 Annual Report. 

Contract No. 0104-CT-32149. Submitted to U.S. Department of Interior, Anchorage, 

AK. 

Galginaitis, M. (2008). cANIMIDA Task 7. Draft Annual Assessment of Subsistence 

Bowhead Whaling Near Cross Island, 2005. cANIMIDA Task 7 Annual Report. 

Contract No. 0104-CT-32149. Submitted to U.S. Department of Interior, Anchorage, 

AK. 

Galginaitis, M. (2006). cANIMIDA Task 7. Annual Assessment of Subsistence 

Bowhead Whaling Near Cross Island, 2004. cANIMIDA Task 7 Annual Report. 

Contract No. 0104-CT-32149. Submitted to U.S. Department of Interior, Anchorage, 

AK. 
A-4

ANIMIDA 

(Arctic Nearshore Impact Monitoring in Development Area) 

Brown, J.S. (2005) Core Contractor Program Management, Logistics, Database, and 

Reporting: Phase II Final Summary Report. ANIMIDA Task Order 1 Final Report. Outer

Continental Shelf Study MMS 2005-051, U.S. Department of Interior, Anchorage, AK. 

Brown, J., P. Boehm, L. Cook, and J. Trefry. (2004) ANIMIDA Task 2 Hydrocarbon and 

Metal Characterization of Sediment Cores in the ANIMIDA Study Area, OCS Study 

MMS 2004-023. USDOI, MMS, Alaska OCS Region, Anchorage, AK. 

Brown, J.S., Boehm, P., Cook, L., Trefry, J.H. and Smith, W. (2004) Hydrocarbon and 

Metal Characterization of Sediments, Bivalves and Amphipods in the ANIMIDA Study 

Area. ANIMIDA Task Order 2 Final Report. Outer Continental Shelf Study MMS 2004-

024, U.S. Department of Interior, Anchorage, AK. 

 

Michael Galginaitis and Dale W. Funk. (2004). Annual Assessment of Subsistence 

Bowhead Whaling Near Cross Island: 2001 and 2002 – ANIMIDA Task Order 4 Final 

Report. Outer Continental Shelf Study MMS 2004-30, U.S. Department of Interior, 

Anchorage, AK. 

Michael Galginaitis and Dale W. Funk (2004). Annual Assessment of Subsistence 

Bowhead Whaling Near Cross Island: 2003 – ANIMIDA Task Order 4. Outer 

Continental Shelf Study MMS 2005-25 U.S. Department of Interior, Anchorage, AK. 

Trefry, J.H., Rember, R.D., Trocine, R.P. and Savoie, M. (2004). Sources, 

Concentrations and Dispersion Pathways for Suspended sediment in the Coastal Beaufort 

Sea. ANIMIDA Task Order 5 Final Report. Outer Continental Shelf Study MMS 2004-32, 

U.S. Department of Interior, Anchorage, AK. 

Dunton, K., Burd, A., Funk, D., and Maffione, R. (2004). Linking Water Turbidity and 

Total Suspended Solids Loading to Kelp Productivity within the Stefansson Sound 

Boulder Patch. ANIMIDA Task Order 6 Final Report. Outer Continental Shelf Study 

MMS 2005-11, U.S. Department of Interior, Anchorage, AK. 

Trefry, J.H., Rember, R.D., Trocine, R.P. and Brown, J.S. (2004) Partitioning of potential 

contaminants between dissolved and particulate phases in waters of the coastal Beaufort 

Sea. ANIMIDA Task Order 7 Final Report. Outer Continental Shelf Study MMS 2004-

031, U.S. Department of Interior, Anchorage, AK. 

Spies, R., Hardin, D., Gold, J. and Bell, D. (2003) Baseline Characterization of 

Anthropogenic Contaminants in biota Associated with the Alaska OCS Liberty and 

Northstar Oil and Gas Production Unit in the Nearshore Beaufort Sea. ANIMIDA Task 

Order 8 Final Report. Outer Continental Shelf Study MMS 2003-071, U.S. Department of 

Interior, Anchorage, AK. 
A-5

Boehm, P. (2001) ANIMIDA Phase I: Arctic Nearshore Characterization and 

Monitoring of the Physical Environment in the Northstar and Liberty Development Areas 

Final Report OCS Study MMS 2001-104. Prepared by Arthur D. Little, Inc. for USDOI, 

MMS Alaska OCS Region, Anchorage, AK 

Shepard, G. W., Krumhansl, P. A., Knack, M. L., and C. I. Malme. (2001) ANIMIDA 

Phase I: Ambient and Industrial Noise Measurements Near The Northstar and Liberty 

Sites During April 2000. OCS Study MMS 2001-047. Prepared by BBN Technologies for 

USDOI, MMS, Alaska OCS Region, Anchorage.
A-6

JOURNAL PUBLICATIONS

Dunton, K. H., S. V. Shonberg, and D. W. Funk. 2009. Interannual and spatial variability 

in Light attenuation: Evidence from three decades of growth in the kelp Laminaria 

solidungula. In: Smithsonian at the Poles: Contributions to International Polar Year 

Science, pp.271-284. Smithsonian Institution Scholarly Press, Washington DC. 

Dunton, K.H., S.V. Schonberg, and D.W. Funk. Interannual and spatial variability in 

light attenuation: evidence from three decades of growth in the arctic kelp, Laminaria 

solidungula. In: Proceedings of Smithsonian at the Poles Symposium, Smithsonian 

Institution, Washington, D.C., 3-4 May 2007. M. Lang (eds.), pg 271-284. Washington 

D.C. Smithsonian Institute Scholarly Press. 

Dunton, K.H., T. Weingartner and E.C. Carmack. (2006). The nearshore western 

Beaufort Sea ecosystem: circulation and importance of terrestrial carbon in arctic coastal 

food webs. Progress in Oceanography 71:362-378. 

Aumack, C.F., K.H. Dunton, A.B. Burd, D.W. Funk, and R.A. Maffione. (2007). 

Linking light attenuation and suspended sediment loading to benthic productivity within 

an arctic kelp bed community. Journal of Phycology 43:853-863. 

Alkire, M.B. and Trefry, J.H. (2006) Transport of spring floodwater from rivers under ice 

to the Alaskan Beaufort Sea. Journal of Geophysical Research, Vol. 111, C12008, 

doi:10.1029/2005JC003446, 2006. 

Rember, R.D. and Trefry, J.H. (2004) Increased concentrations of dissolved trace metals 

and organic carbon during snowmelt in rivers of the Alaskan Arctic. Geochimica et 

Cosmochimica Acta 68:477-489, doi: 1016/S0016-7037(03)00458-7.

Trefry, J.H., Rember, R.D., Trocine, R.P. and Brown, J.S. (2003) Trace metals in 

sediments near offshore oil exploration and production sites in the Alaskan Arctic. 

Environmental Geology 45:149-160, doi: 10.1007/s00254-003-0882-2. 

cANIMIDA Task 1 journal publication – being prepared. 

cANIMIDA Task 2 journal publication – being prepared. 

cANIMIDA Task 5 journal publication – being prepared. 

cANIMIDA Task 7 journal publication – being prepared. 
A-7

CONFERENCE/MEETING PRESENTATIONS 

Durell, G., Neff, J., Trefry, J., Brown, J., Hardin, J., Prentki, R. (2010). The cANIMIDA 

Project: Monitoring of Sediment and Biota in Nearshore Oil and Gas Development and 

Production Areas in the Arctic Beaufort Sea, Alaska. Presented at the Alaska Marine 

Science Symposium, January 18-22, 2010, Anchorage, Alaska. 

Durell, G., Neff, J., Brown, J., and Trefry, J. (2008). Contaminants in sediment and biota 

from the oil and gas development and production areas in the Arctic Beaufort Sea, 

Alaska. Presented at 29th Annual Meeting in North America of the Society of 

Environmental Toxicology and Chemistry in Tampa, FL, on November 17, 2008. 

Durell, G. (2008) Continuation of arctic nearshore impact monitoring in development 

area (cANIMIDA): Introduction and Overview. Presented at Alaska OCS Region 11th 

Information Transfer Meeting in Anchorage, AK, on October 30, 2008. Abstract 

published in Final Proceedings of the Alaska OCS Region Eleventh Information Transfer 

Meeting, OCS Study MMS 2009-005, pp. 51. 

Brown, J., Cook, L., Trefry, J. and Durell, G. (2008) cANIMIDA: Hydrocarbon 

characterization of sediments in the nearshore Beaufort Sea. Presented at Alaska OCS 

Region 11th Information Transfer Meeting in Anchorage, AK, on October 30, 2008. 

Abstract published in Final Proceedings of the Alaska OCS Region Eleventh Information 

Transfer Meeting, OCS Study MMS 2009-005, pp. 52-54. 

Trefry, J.H., Trocine, R.P., Semmler, C.M., Alkire, M.B., Rember, R.D., and Savoie, M. 

(2008). cANIMIDA: Trace metals as indicators of human activities in the coastal 

Beaufort Sea. Presented at Alaska OCS Region 11th Information Transfer Meeting in 

Anchorage, AK, on October 30, 2008. Abstract published in Final Proceedings of the 

Alaska OCS Region Eleventh Information Transfer Meeting, OCS Study MMS 2009-005, 

pp. 54-55. 

Neff, J., Hardin, J., Durell., G. (2008). cANIMIDA: Integrated biomonitoring of 

petroleum hydrocarbons in marine animals from the cANIMIDA study area. Presented at 

Alaska OCS Region 11th Information Transfer Meeting in Anchorage, AK, on October 

30, 2008. Abstract published in Final Proceedings of the Alaska OCS Region Eleventh 

Information Transfer Meeting, OCS Study MMS 2009-005, pp. 56-57. 

Dunton, K., Funk, D, Iken, K., and Schonberg, S. (2008) cANIMIDA: Long-term 

monitoring of the Boulder Patch kelp ecosystem in the cANIMIDA study area. Presented 

at Alaska OCS Region 11th Information Transfer Meeting in Anchorage, AK, on October 

30, 2008. Abstract published in Final Proceedings of the Alaska OCS Region Eleventh 

Information Transfer Meeting, OCS Study MMS 2009-005, pp. 58-59. 

Galginaitis, M. S. 2008. Variability in Cross Island (Arctic Alaska) Subsistence Whaling: 

An Examination of Natural and Anthropogenic Factors. In US-Canada Northern Oil and 

Gas Research Forum Held October 28-30, 2008, in Anchorage, AK: US-Canada Northern 
A-8

Oil and Gas Research Forum. Abstract published in Final Proceedings of the Alaska 

OCS Region Eleventh Information Transfer Meeting, OCS Study MMS 2009-005, pp. 101 

and in Final Proceedings of the Northern Oil and Gas Research Forum (October 28-30, 

2008) Meeting, pp. 239-244. 

Weingartner, T J; Danielson, S L; Kasper, J. (2008). Seasonal variations in circulation 

and water properties in the nearshore Beaufort Sea. Presented at Alaska OCS Region 11th

Information Transfer Meeting in Anchorage, AK, on October 29, 2008. Abstract 

published in Final Proceedings of the Alaska OCS Region Eleventh Information Transfer 

Meeting, OCS Study MMS 2009-005, pp. 27. 

Weingartner, T J. (2008). Ongoing and suggested efforts in understanding the 

oceanography of the Alaskan Beaufort Sea. Presented at Alaska OCS Region 11th

Information Transfer Meeting in Anchorage, AK, on October 29, 2008. Abstract 

published in Final Proceedings of the Alaska OCS Region Eleventh Information Transfer 

Meeting, OCS Study MMS 2009-005, pp. 28-29. 

Dunton, K H; Schonberg, S V. (2008). Evidence for the Incorporation of Terrestrial 

Carbon in Arctic Coastal Food Webs in the Western Beaufort Sea Presented at the 2008 

ASLO/Ocean Sciences Meeting in Orlando, FL, on March 6, 2008. 

Trefry, J H; Trocine, R P; Semmler, C M; Savoie, M A. (2008). Defining natural rivershelf interactions for trace metals in the costal Beaufort Sea. Presented at the 2008 

ASLO/Ocean Sciences Meeting in Orlando, FL, on March 6, 2008. 

Brown, J S; Cook, L L; Boehm, P D; Trefry, J H; Durell, G S. (2008). Hydrocarbon 

distribution in sediments of the nearshore Beaufort Sea. Presented at the 2008 

ASLO/Ocean Sciences Meeting in Orlando, FL, on March 6, 2008. 

Neff, J M; Hardin, J L; Durell, G S; Himmer, T M. (2008). Hydrocarbons and metals in 

tissues of benthic crustaceans and mollusks from near-shore Beaufort Sea: Possible 

effects of oil and gas development. Presented at the 2008 ASLO/Ocean Sciences 

Meeting in Orlando, FL, on March 6, 2008. 

Weingartner, T J; Danielson, S L; Kasper, J. (2008). Circulation in the landfast-ice zone 

of the Alaskan Beaufort Sea. Presented at the 2008 ASLO/Ocean Sciences Meeting in 

Orlando, FL, on March 4, 2008. 

Kasper, J L; Weingartner, T. (2008). Modeling circulation in the landfast ice zone. 

Presented at the 2008 ASLO/Ocean Sciences Meeting in Orlando, FL, on March 4, 2008. 

Hardin, J L; Neff, J M; Durell, G S; Himmer, T M. (2008). Meauring bioavailable 

hydrocarbons in the nearshore Beaufort Sea: Comparison of caged mussels (Mytilus

trossulus) and semipermeable membrane devices (SPMDs). Presented at the 2008 

ASLO/Ocean Sciences Meeting in Orlando, FL, on March 4, 2008. 
A-9

Savoie, M A; Trefry, J H; Trocine, R P. (2008). Under-ice interactions and mixing of 

spring floodwaters with continental shelf water in the Alaskan Beaufort Sea. Presented at 

the 2008 ASLO/Ocean Sciences Meeting in Orlando, FL, on March 4, 2008. 

Galginaitis, M S. (2008). Variability in Cross Island (Arctic Alaska) subsistence 

whaling: An examination of natural and anthropogenic factors. Presented at the 2008 

ASLO/Ocean Sciences Meeting in Orlando, FL, on March 4, 2008. 

 

Trefry, J.H., Trocine, R.P., Semmler, C.M., Alkire, M.B., Savoie, M.A. and R.D. 

Rember. (2007). Transport and fate of spring floodwater from rivers in the Alaskan 

Beaufort Sea. Presented at the 2007 Meeting of the American Estuarine Research 

Federation in Providence, RI, November 4-8, 2007. 

Galginaitis, M. (2007). Aspects of Inupiat Subsistence Whaling at Cross Island, Alaska & 

Whaler Perceptions of Industry Influences on Whaling-2006. Presented at the 

NMFS/MMS Open Water Meeting, 10 April 2007, Anchorage, Alaska. 

Danielson, S and T. Weingartner. (2007). Results from the collection oceanographic 

measurements from three nearshore acoustic doppler current meter profilers (ADCPs) 

along the inner Beaufort sea shelf from Smith Bay to Camden Bay, Alaska. Presented at 

the Alaska Marine Science Symposium. January 2007, Anchorage, AK 

Taylor, K., T. Weingartner, and S. Danielson. (2007). Retrospective Analyses of the 

1945-2005 Barrow Wind Record. Presented at the Alaska Marine Science Symposium. 

January 2007, Anchorage, AK. 

Durell, G.S., J. Brown, J. Neff, and J. Trefry. (2006) Monitoring the Impact of Nearshore 

Development and Production in the Arctic Beaufort Sea, Alaska. 8th SPE Conference of 

Health, Safety, and Environment, Abu Dhabi, UAE, April 2-4, 2006. 

Trefry, J.H., Trocine, R.P., Alkire, M.B., Rember, R.D., Savoie, M.A. and Semmler, 

C.M. (2006) River-shelf interactions during spring floods in the coastal Beaufort Sea. 

Presented at Fall Meeting of the American Geophysical Union in San Francisco, CA on 

December 14, 2006. Abstract published in EOS Transactions of the American 

Geophysical Union 87(52), Fall Meeting Supplement, Abstract C44B-05. 

Galginaitis, M. (2006) Inupiat Subsistence Whaling in Nuiqsut, Alaska. Presented to the 

Society for Applied Anthropology meeting, Vancouver, Canada. March 31, 2006. 

Galginaitis, M. (2006). Aspects of Inupiat Subsistence Whaling in Nuiqsut, Alaska. 

Presented at the NMFS/MMS Open Water Meeting, 18 April 2006, Anchorage, Alaska. 

Weingartner, T, J. Kasper and S. Danielson. (2006). Circulation in the Landfast Ice 

Zone of the Alaskan Beaufort Sea. Presented at Fall Meeting of the American 

Geophysical Union. December 2006, San Francisco, CA 
A-10

Kasper, J. and T. Weingartner (2006). Modeling Circulation in the Landfast Ice Zone. 

Presented at the Alaska Marine Science Symposium. Presented at Fall Meeting of the 

American Geophysical Union. December 2006, San Francisco, CA. 

Alkire, M.B., Trefry, J.H., Rember, R.D., Savoie, M., Trocine, R.P. and Woodall, D. 

(2005) Multi-parameter analysis for movement and mixing of fresh water in an arctic 

estuarine system. Presented at the 69th Annual Meeting of the Florida Academy of 

Sciences in Orlando, FL, on March 18, 2005. Abstract published in Florida Scientist 68: 

Supplement 1, p. 17. 

Prentki, R. T. (2005) cANIMIDA--Continuation of Arctic Nearshore Impact Monitoring 

in Development Area. In: Barrow Information Update Meeting, March 18, 2005, 

Compiler MBC Applied Environmental Sciences Anchorage, AK: United States DOI, 

MMS, Alaska OCS Region. 

Durell, G. (2005) Continuation of Arctic nearshore impact monitoring in development 

area (cANIMIDA): Overview. Presented at Alaska OCS Region Tenth Information 

Transfer Meeting in Anchorage, AK, on March 14, 2005. Abstract published in Final 

Proceedings of the Alaska OCS Region Tenth Information Transfer Meeting, OCS Study 

MMS 2005-036, pp. 33-34. 

Brown, J., Boehm, P., Cook, L., Trefry, J. and Durell, G. (2005) The MMS cANIMIDA 

Program: Hydrocarbon chemistry of sediments in the nearshore Beaufort Sea. Presented 

at Alaska OCS Region Tenth Information Transfer Meeting in Anchorage, AK, on March 

14, 2005. Abstract published in Final Proceedings of the Alaska OCS Region Tenth 

Information Transfer Meeting, OCS Study MMS 2005-036, pp. 35-37. 

Trefry, J.H., Trocine, R.P., Alkire, M.B., Woodall, D.W., Rember, R.D., Savoie, M. and 

Durell, G. (2005) Sources, concentrations and dispersion pathways for suspended 

sediments and partitioning of potential pollutants between dissolved and particulate 

phases. Presented at Alaska OCS Region Tenth Information Transfer Meeting in 

Anchorage, AK, on March 14, 2005. Abstract published in Final Proceedings of the 

Alaska OCS Region Tenth Information Transfer Meeting, OCS Study MMS 2005-036, 

pp. 37-38. 

Neff, J. (2005) Integrated biomonitoring and bioaccumulation of anthropogenic 

compounds in biota of the cANIMIDA study area. Presented at Alaska OCS Region 

Tenth Information Transfer Meeting in Anchorage, AK, on March 14, 2005. Abstract 

published in Final Proceedings of the Alaska OCS Region Tenth Information Transfer 

Meeting, OCS Study MMS 2005-036, pp. 38-39. 

Dunton, K., Funk, D, and Iken, K (2005) Long-term monitoring of the kelp community in 

the Stefansson Sound Boulder Patch: Detection of change related to oil and gas 

development. Presented at Alaska OCS Region Tenth Information Transfer Meeting in 

Anchorage, AK, on March 14, 2005. Abstract published in Final Proceedings of the 
A-11

Alaska OCS Region Tenth Information Transfer Meeting, OCS Study MMS 2005-036, 

pp. 39-42. 

Galginaitis, M. (2005). Annual assessment of subsistence Bowhead whaling near Cross 

Island, 2004. Presented at Alaska OCS Region Tenth Information Transfer Meeting in 

Anchorage, AK, on March 14, 2005. Abstract published in Final Proceedings of the 

Alaska OCS Region Tenth Information Transfer Meeting, OCS Study MMS 2005-036, 

pp. 107-109. 

Alkire, M.B., Trefry, J.H., Rember, R.D., Savoie, M.A., Trocine, R.P. and Woodall, 

D.W. (2004) A Multi-Tracer Analysis for the Study of the Movement and Mixing of 

Fresh Waters in a Shallow Arctic Estuarine System. Presented at Fall Meeting of the 

American Geophysical Union in San Francisco, CA on December 9, 2004. Abstract 

published in EOS Transactions of the American Geophysical Union 85(47), Fall Meeting 

Supplement, Abstract OS41A-0477. 

Trefry, J.H. (2004) Arctic oil. Presented as Keynote Address to the Interdisciplinary 

Environmental Association in Boston, MA, on July 2, 2004. 

Galginaitis, M. (2004). Contemporary Bowhead Subsistence Whaling in a Small Alaskan 

Community. Presented to the American Cetacean Society Monterey Bay Chapter, 

Monterey, California. December 2, 2004. 

Frey, C.L. and Wood, S.L. (2003) Development of an autonomous underwater vehicle for 

sub-ice environmental monitoring in Prudhoe Bay, Alaska. Presented at OCEANS 2003 

in San Diego, CA, on September 23, 2003. Paper published in OCEANS 2003. 

Proceedings, Volume: 2, pages 1161- 1173 (ISBN: 0-933957-30-0). 

Trefry, J.H., Rember, R.D., Trocine, R.P. and Savoie, M.A. (2003) Sources, 

concentrations, composition and dispersion pathways for suspended sediment in the in 

the coastal Beaufort Sea. Presented at 24th Annual Meeting in North America of the 

Society of Environmental Toxicology and Chemistry in Austin, TX, on November 12, 

2003. 

Trocine, R.P., Trefry, J.H. and Rember, R.D., (2003) Trace metals in sediments near 

offshore oil exploration and production sites in the coastal Beaufort. Presented at 24th

Annual Meeting in North America of the Society of Environmental Toxicology and 

Chemistry in Austin, TX, on November 12, 2003. 

Spies, R. B. , J. Gold, D. Hardin, and D. Bell. (2003) Trace Substances and Biomarkers in 

Fish From the North Slope of Alaska." Presented at 24th Annual Meeting in North 

America of the Society of Environmental Toxicology and Chemistry in Austin, TX, on 

November 12, 2003. 

Rember, R.D., Trefry, J.H. and Trocine, R.P. (2003) Riverine transport and fate of 

dissolved trace metals in the coastal Beaufort Sea. Presented at 24th Annual Meeting in 
A-12

North America of the Society of Environmental Toxicology and Chemistry in Austin, 

TX, on November 12, 2003. 

Galginaitis, M. (2003) Annual Assessment of Subsistence Bowhead Whaling Near 

Cross Island, 2001-2002: ANIMIDA Task Order 004. Presented at 24th Annual Meeting 

in North America of the Society of Environmental Toxicology and Chemistry in Austin, 

TX, on November 12, 2003. 

Brown, J. S. , P. Boehm, and L. Cook. (2003) The ANIMIDA Program: Hydrocarbon 

Chemistry of Sediments and Biota in the Nearshore Beaufort Sea. Presented at 24th

Annual Meeting in North America of the Society of Environmental Toxicology and 

Chemistry in Austin, TX, on November 12, 2003. 

Boehm, P., and J. S. Brown. (2003) The ANIMIDA Program: Introduction to a MultiYear Monitoring Program in the Nearshore Beaufort Sea. Presented at 24th Annual 

Meeting in North America of the Society of Environmental Toxicology and Chemistry in 

Austin, TX, on November 12, 2003. 

Dunton, K., C. Aumack, A. Burd, D. Funk, and R. Maffione. (2003) Linking Water 

Turbidity and TSS Loading to Kelp Production Within the Stefansson Sound Boulder 

Patch. Presented at 24th Annual Meeting in North America of the Society of 

Environmental Toxicology and Chemistry in Austin, TX, on November 12, 2003. 

Rember, R.D. and Trefry, J.H. (2003) Increased concentrations of dissolved organic 

carbon during the spring floods in the Sagavanirktok, Kuparuk and Colville rivers in the 

Alaskan Arctic. Presented at Fall Meeting of the American Geophysical Union in San 

Francisco, CA on December 8, 2003. Abstract published in EOS Transactions of the 

American Geophysical Union 85(47), Fall Meeting Supplement, Abstract B22D-05. 

Galginaitis, M. (2003). Annual Assessment of Subsistence Bowhead Whaling Near Cross 

Island, 2002: ANIMIDA Task Order 004 2002 Annual Report of Results. Presentation to 

the Quarterly Meeting of the Alaska Eskimo Whaling Commission, Fairbanks, Alaska 

(07/18/2003). 

Brown, J. S. , and P. Boehm. (2003) The Minerals Management Service Arctic Nearshore 

Impact Monitoring in the Development Area (ANIMIDA) Program: Introduction to a 

Multi-Year Monitoring Program in the Nearshore Beaufort Sea. In: Alaska OCS Region 

Ninth Information Transfer Meeting And Barrow Information Update Meeting Final 

Proceedings, Preparer MBC Applied Environmental Sciences, pp. 21-22. OCS Study 

MMS 2003-042. Anchorage, AK.: United States, DOI, MMS, Alaska OCS Region 

Brown, J. S. , P. Boehm, and L. Cook. (2003) Hydrocarbon Chemistry of Sediments and 

Biota in the Nearshore Beaufort Sea. In: Alaska OCS Region Ninth Information 

Transfer Meeting And Barrow Information Update Meeting Final Proceedings, Preparer 

MBC Applied Environmental Sciences, p.22. OCS Study MMS 2003-042. Anchorage, 

AK.: United States, DOI, MMS, Alaska OCS Region 
A-13

Galginaitis, M. (2003) ANIMIDA: Annual Assessment of Subsistence Bowhead 

Whaling Near Cross Island. In: Alaska OCS Region Ninth Information Transfer Meeting 

And Barrow Information Update Meeting Final Proceedings, Preparer MBC Applied 

Environmental Sciences, pp. 73-75. OCS Study, no. MMS 2003-042. Anchorage, AK.: 

United States, DOI, MMS, Alaska OCS Region. 

Rember, R. D., J. H. Trefry, and R. P. Trocine. (2003) Partitioning of Potential 

Contaminants Between Dissolved and Particulate Phases. In: Alaska OCS Region Ninth 

Information Transfer Meeting And Barrow Information Update Meeting Final 

Proceedings, Preparer MBC Applied Environmental Sciences, pp. 24-25. OCS Study 

MMS 2003-042. Anchorage, AK.: United States, DOI, MMS, Alaska OCS Region. 

Trefry, J. H., R. P. Trocine, and R. D. Rember. (2003) Sources, Concentrations, and 

Dispersion Pathways for Suspended Sediment. In: Alaska OCS Region Ninth 

Information Transfer Meeting And Barrow Information Update Meeting Final 

Proceedings, Preparer MBC Applied Environmental Sciences, pp. 23-24. OCS Study, no. 

MMS 2003-042. Anchorage, AK.: United States, DOI, MMS, Alaska OCS Region. 

Dunton, K. H., R. Maffione, and A. Burd. "Linking Water Turbidity and TSS Loading to 

Kelp Productivity Within the Stefansson Sound Boulder Patch." In: Alaska OCS Region 

Ninth Information Transfer Meeting And Barrow Information Update Meeting Final 

Proceedings, Preparer MBC Applied Environmental Sciences, pp. 25-26. OCS Study, no. 

MMS 2003-042. Anchorage, AK.: United States, DOI, MMS, Alaska OCS Region, 2003. 

Rember, R.D. (2002) Dissolved metals in Arctic rivers. Presented at DISCO XVII 

(Dissertations Symposium in Chemical Oceanography) in Honolulu, HI, on May 8, 2002, 

sponsored by NOAA, NSF and ONR. 

 

Rember, R.D. and Trefry, J.H. (2002) Concentrations of dissolved and particulate trace 

metals and organic carbon in rivers of the Alaskan Arctic during break-up. Presented to 

American Association for the Advancement of Science, Arctic Division, Hydrology 

Session in Fairbanks, AK, on September 19, 2002. 

Brown, J., P. Boehm, and L. Cook. (2001) "ANIMIDA: Hydrocarbon Chemistry of 

Sediments and Biota in the Nearshore Beaufort Sea." Abstract published in Final 

Proceedings of the Alaska OCS Region Eighth Information Transfer Meeting, OCS Study 

MMS 2001-049, p. 28. 

Brown, J., P. Boehm, and L. Cook. (2001) "Arctic Nearshore Impact Monitoring in 

Development Area (ANIMIDA) Program: A Multi-Year Monitoring Program in the 

Nearshore Beaufort Sea." Abstract published in Final Proceedings of the Alaska OCS 

Region Eighth Information Transfer Meeting, OCS Study MMS 2001-049, p. 29. 

Shepard, G. W., P. A. Krumhansl, M. L. Knack, and C. I. Malme. (2001) ANIMIDA: 

Ambient and Industrial Noise Measurements Near The Northstar and Liberty Sites 
A-14

During April 2000. Abstract published in Final Proceedings of the Alaska OCS Region 

Eighth Information Transfer Meeting, OCS Study MMS 2001-049. 

Trefry, J.H., Trocine, R.P. and Rember, R.D. (2001) Trace metals in the ANIMIDA study 

area. Presented at Alaska OCS Region Eighth Information Transfer Meeting in 

Anchorage, AK, on April 3, 2001. Abstract published in Final Proceedings of the Alaska 

OCS Region Eighth Information Transfer Meeting, OCS Study MMS 2001-049, pp. 35-

36. 

Brown, J. S., P. D. Boehm, and J. H. Trefry. (2000) The Minerals Management Service 

Arctic Nearshore Impact Monitoring in the Development Area (ANIMIDA) Program: 

Phase I of a Multi-Year Monitoring Program in the Nearshore Beaufort Sea. Presented at 

23rd Arctic and Marine Oilspill Program (AMOP) Technical Seminar Ottawa, Canada: 

Environment Canada. 
A-15

THESES, DISSERTATIONS, and OTHER 

Galginaitis, M. (2007). Summary of the 2006 subsistence whaling season at Cross 

Island. Draft Chapter 3 In: W.J. Richardson (ed.). 2007. Monitoring of industrial sounds, 

seals, and bowhead whales near BP’s Northstar oil development, Alaskan Beaufort Sea, 

2005: Annual summary report. Rep. from LGL Ltd. (King City, Ont.) and Greeneridge 

Sciences Inc. (Santa Barbara, CA) for BP Explor. (Alaska) Inc., Anchorage, AK. 

Galginaitis, M. (2007). Summary of the 2005 and previous subsistence Whaling Seasons 

at Cross Island. Chapter 12 In: W.J. Richardson (ed.). 2006. Monitoring of industrial 

sounds, seals, and bowhead whales near BP’s Northstar oil development, Alaskan 

Beaufort Sea, 1999–2004. LGL Rep. TA4256A. Rep. from LGL Ltd. (King City, Ont.), 

Greeneridge Sciences Inc. (Santa Barbara, CA) and WEST Inc. (Cheyenne, WY) for BP 

Explor. (Alaska) Inc., Anchorage, AK. 

Galginaitis, M. (2006). Summary of the 2005 subsistence whaling season at Cross 

Island. Chapter 3 In: W.J. Richardson (ed.). 2006. Monitoring of industrial sounds, seals, 

and bowhead whales near BP’s Northstar oil development, Alaskan Beaufort Sea, 2005: 

Annual summary report. Rep. from LGL Ltd. (King City, Ont.) and Greeneridge Sciences 

Inc. (Santa Barbara, CA) for BP Explor. (Alaska) Inc., Anchorage, AK. 

Semmler, C.M. (2006) Sources, cycling, and fate of arsenic and mercury in the coastal 

Beaufort Sea, Alaska. M.S. Thesis, Florida Institute of Technology, Melbourne, 70 pp. 

Alkire, M.B. (2005) Using geochemical tracers to infer flow pathways and mixing of two 

Alaskan Arctic river plumes under ice. M.S. Thesis, Florida Institute of Technology, 

Melbourne, 140 pp. 

Braddock. J. F., K. A. Gannon, and B. T. Rasley. (2004) Petroleum HydrocarbonDegrading Microbial Communities in Beaufort-Chukchi Sea Sediments,. OCS Study 

MMS 2004-061. University of Alaska Fairbanks, CMI and USDOI, MMS, Alaska OCS 

Region, Fairbanks, AK, 2004. [provided logistical support and co-sampled]. 

Rember, R.D. (2002) Composition of dissolved and suspended matter transported by the 

Sagavanirktok, Kuparuk and Colville Rivers in the Alaskan Arctic. Ph.D. Dissertation, 

Florida Institute of Technology, Melbourne, 107 pp. 

Frey, C.L. (2002) Development of an autonomous underwater vehicle for sub-ice 

environmental monitoring in Prudhoe Bay, Alaska. M.S. Thesis, Florida Institute of 

Technology, Melbourne, 152 pp. 

Gannon, K. A. (2002) "Petroleum Hydrocarbon Degrading Microbial Communities of 

Arctic Ocean Sediment." M.S. Thesis. University of Alaska Fairbanks. [provided 

logistical support and co-sampled]. 

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-50

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Kotzebue

Sound

C h u k c h i

S e a

Ledyard

Bay

Bering Strait

Kolyuchin

Bay

Wrangel Island

Herald Island

Diomede

Islands

C H U K C H I

A U T O N O M O U S

O K R U G

S e w a r d

U

NITED

STATES

C h u k o t s k

P e n i n s u l a

L i s b u r n e

P e n i n s u l a

(Interna

tio

n

al Date

Lin

e)

RUSSIA

Inchoun R.

Mechigmensk

Bay

Arakamchechen

Ild

Amgue m a

R.

Kotzebue

Kivalina

Diomede

Brevig

Mission

Point

Hope

Point

Lay

Wa

Shishmaref

Noatak

Provideniya

176°0'0"E 180°0'0" 176°0'0"W 172°0'0"W 168°0'0"W 164°0'0"W 

DRAFT August 2009

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Duxbury, Massachusetts 02332

Phone: (781) 934-0571

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