NOAA Technical Memorandum NOS ORCA 110 

Evaluation of the Condition of Prince William Sound 

Shorelines Following the Exxon Valdez Oil Spill and 

Subsequent Shoreline Treatment: 

Volume I 1995 Biological Monitoring Survey 

Seattle, Washington 

March 1997 

n 0 a a NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION 

National Ocean Service 
Office of Ocean Resources Conservation and Assessment 

National Ocean Service 

National Oceanic and Atmospheric Administration 

U.S. Department of Commerce 

The Office of Ocean Resources Conservation and Assessment (ORCA) provides 

decisionmakers comprehensive, scientific information on characteristics of the 

oceans, coastal areas, and estuaries of the United States of America. The 

information ranges from strategic, national assessments of coastal and estuarine 

environmental quality to real-time information for navigation or hazardous materials 

spill response. Through its National Status and Trends (NS&T) Program, ORCA 

uses uniform techniques to monitor toxic chemical contamination of bottom-feeding 

fish, mussels and oysters, and sediments at about 300 locations throughout the 

United States. A related NS&T Program of directed research examines the 

relationships between contaminant exposure and indicators of biological responses 

in fish and shellfish. 

ORCA provides critical scientific support to the U.S. Coast Guard during spills of 

oil or hazardous materials into marine or estuarine environments. This support 

includes spill trajectory predictions, chemical hazard analyses, and assessments of 

the sensitivity of marine and estuarine environments to spills. The program 

provides similar support to the U.S. Environmental Protection Agency's Superfund 

Program during emergency responses at, and for the cleanup of, abandoned 

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of Commerce as a trustee for living marine resources, ORCA conducts 

comprehensive assessments of damages to coastal and marine resources from 

discharges of oil and hazardous materials. 

ORCA collects, synthesizes, and distributes information on the use of the coastal 

and oceanic resources of the United States to identify compatibilities and conflicts 

and to determine research needs and priorities. It conducts comprehensive, 

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areas for decisionmaking by NOAA, other Federal agencies, state agencies, 

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organizations: Coastal Monitoring and Bioeffects Assessment Division, Hazardous 

Materials Response and Assessment Division, Strategic Environmental Assessment 

Division, and the Damage Assessment Center. 
NOAA Technical Memorandum NOS ORCA 110 

Evaluation of the Condition of Prince William Sound 

Shorelines Following the Exxon Valdez Oil Spill and 

Subsequent Shoreline Treatment 

Volume I 1995 Biological Monitoring Survey 

Jonathan P. Houghton, Principal Investigator 

Robert H. Gilmour 

Pentec Environmental, Inc. 

120 Third Avenue South, Suite 100 

Edrnonds, Washington 98020 

Dennis C. Lees, Principal Investigator 

Ogden Environmental and Energy Services Co., Inc. 

5510 Morehouse Drive 

San Diego, California 92121 

William B. Driskell 

6536 20th Avenue NE 

Seattle,' Washington 98115 

Sandra C. Lindstrom 

13965 64th Avenue 

Surrey, B.C. Canada V3WlY7 

Edited By: 

Gary Shigenaka 

NOAA Hazardous Materials Response and Assessment Division 

7600 Sand Point W.ay Northeast 

Seattle, Washington 98115 

Seattle, Washington 

United States National Oceanic and National Ocean Service 

Department of Commerce Atmospheric Administration W. Stanley Wilson 

William Daley D. James Baker Assistant Administrator 

*etary Under Secretary for Oceans for Ocean Services and 

and Atmosphere Coastal Zone Management 
Hazardous Materials Response and Assessment Division 

Office of Ocean Resources Conservation and Assessment 

National Ocean Service 

National Oceanic and Atmospheric Administration 

U.S. Department of Commerce 

Silver Spring, Maryland 

NOTICE 

This report has been reviewed by the National Ocean Service of the National Oceanic and Atmospheric 

Administration (NOAA) and approved for publication. Such approval does not signify that the contents of 

this report necessarily represent the official position of NOAA or of the Government of the United States, 

nor does mention of trade names or commercial products constitute endorsement or recommendation for 

their use. 
CONTENTS 

CHAPTER PAGE 

INTRODUCTION 

GENERAL ................................................................................ 1-1 

SAMPLING OBJECTIVE AND APPROACH ............................... 1-3 

Objectives ........................................................................... 1-3 

Approach and Field Work Accomplished ............................ 1-3 

Hypotheses Tested ............................................................. 1-6 

SAMPLING DESIGN ................................................................. 1-6 

SITE CLASSIFICATION. OILING. AND TREATMENT 

HISTORY ............................................................................ 1-9 

THE STUDY AREA ................................................................ 1 . 12 

REPORT ORGANIZATION ..................................................... 1 . 12 

2 INTERTIDAL EPIBIOTA 

INTRODUCTION ...................................................................... 2-1 

METHODS ............................................................................... 2. 1 

Field ................................................................................... 2-1 

Statistical Analyses ............................................................. 2-3 

RESULTS AND DISCUSSION ................................................... 2-5 

Physical Measurements ...................................................... 2-5 

Biological Conditions ........................................................ 2- 10 

3 MOLLUSK STUDIES 

INTRODUCTION ..................................................................... -3-1 

METHODS ............................................................................... 3. 1 
1995 Summer Monitoring 

CONTENTS continued 

CHAPTER 

3 

PAGE 

Field Transplant Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3- 1 

Clam Aging Conventions .. . . ... . .. . . .. .. . .. . . . .. . .. . . . . . .. ... . . . . . .. . . . . .3-2 

Recruitment Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4 

Statistical Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6 

RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6 

Littleneck Clam Transplant Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6 

Recruitment Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9 

GENERAL DISCUSSIQN, SUMMARY, AND 

CONCLUSIONS 

OVERALL IMPLICATIONS OF THE FINDINGS . . . . . . . . . . . . . . . . . . . .4- I 

EPIBIOTAL ASSEMBLAGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4 

INFAUNAL EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8 

REFERENCES AND ACRONYMS 

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . -5- 1 

ACRONYMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -5-3 

APPENDIX A ... .. . . .. . . . . . . . . .. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . A- I 

APPENDIX B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B- I 

APPENDIX C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C- I 
1995 Summer Monitoring 

LIST OF FIGUFWS 

Figure 1-1 

Figure 1-2 

Figure 2-1 

Figure 2-2 

Figure 2-3 

Figure 2-4 

Figure 2-5 

Figure 2-6 

Figure 2-7 

Figure 2-8 

Figure 2-9 

Figure 2-10 

Figure 2-11 

Figure 2-12 

Figure 2-13 

Figure 2-14 

Typical site layout. ............................................................................................ 1-10 

Prince William Sound study area and sampling~locations (asterisks). 

Sampling locations for 1994 are shown in bold. ............................................. 1-13 

Mean percent cover (+I SE) of Fucus from upper rocky stations, by 

category, and from selected upper rocky stations 1989-95. Number of 

stations sampled (n) for each category, shown below axis. ........................... 2-12 

Mean abundance (+I SE) of littorine snails from upper rocky stations, 

by category, 1989-95. ............................................................................................ 2-13 

Mean abundance (+I SE) of Lottiidae from upper rocky stations, by 

category, 1989-95.. ............................................................................................. 2-14 

Mean percent cover (f 1 SE) of Fucus from middle rocky stations, by 

category, 1989-95. .................................................................................................. 2-16 

Mean percent cover (21 SE) of Fucus germlings from middle rocky 

stations, by category, 1989-95. ............................................................................ 2-17 

Mean abundance (f 1 SE) of littorine snails from middle rocky stations, 

by category, 1989-95. ............................................................................................ 2-19 

Mean abundance (k1 SE) of Lottiidae from middle rocky stations, by 

category, 1989-95. ................................................................................................. 2-20 

Mean percent cover (f1 SE) of mussels from middle rocky stations, by 

category, 1989-95. .................................................................................................. 2-21 

Mean percent cover (+I SE) of Balanomorpha from the middle rocky 

stations, by category, 1989-95. ............................................................................ 2-23 

Mean abundance (+I SE) of Nucella from middle rocky stations, by 

category, 1989-95. ............................................................................................... -2-24 

Mean percent total algal cover and total number of algal species' sites 

from the Northwest Bay West Arm middle rocky stations, 1989-95. ........... 2-26 

Mean percent cover of Fucus and mean abundance of Lottiidae from 

the Northwest Bay West Arm middle rocky stations, 1989-95 ...................... 2-27 

Mean percent cover of total erect red algae and Gloiopeltis from the 

Northwest Bay West Arm middle rocky stations, 1989-95. ........................... 2-28 

Mean percent cover of Semibalanus balanoides and mean abundance of 

Nucella from the Northwest Bay West Arm middle rocky stations, 

1989-95. .................................................................................................................. 2-30 
1995 Summer Monitoring 

CONTENTS confinued 

List of Figures continued 

Figure 2-15 

Figure 3-1 

Figure 3-2 

Figure 3-3 

Figure 3-4 

Figure 3-5 

Table 1-1 

Table 1-2 

Table 2-1 

Table 2-2 

Table 2-3 

Table 2-4 

Table 3-1 

Mean abundance of Littorina sitikana and Littorine sputulete from the 

Northwest Bay West Arm middle rocky stations, 1989-95. ............................ 2-31 

Experimental design and number of clams transplanted and recovered 

in the 1994-95 littleneck clam transplant experiment. ....................................... 3-3 

Grain size distribution for test sediments used in the littleneck clam 

recruitment experiment, 1994-95. ........................................................................ .3-5 

Percent recovery and mean growth of live Protothca staminea from 

transplant quadrats at Block Island. .................................................................... 3-8 

Mean growth of age 5,6, and 7 Protothca staminea from the clam 

transplant experiment, 1994-95. .......................................................................... 3-10 

Mean abundance (No./0.009 m2 core) of age 0 and 1 Protothca staminea 

from summer cruises, 1990-95. *Value is mean of all sediment lots for 

a site. ....................................................................................................................... 3-14 

LIST OF TABLES 

Intertidal rocky stations sampled in 1989-95 by oiling/ treatment 

category. 1-5 

Intertidal infauna stations sampled in 1989-95 by oiling/treatment 

category. 1-8 

Mean abundance (% or no./0.25 m2) of important epibiota at upper 

rocky stations, July 1995 (*p I 0.10 **o I 0.05). 2-6 

Mean abundance (% or no./0.25 m2) of important epibiota at three 

upper rocky intertidal transects at Elrington Islet, July 1995 ("p 10.10). 2-7 

Mean abundance (% or no./0.25 m2) of important epibiota at Northwest 

Bay West Arm middle rocky stations, September 1989 (n - 4,4), July 1991 

(n-5,5), July 1992 (n - 5,5), July 1993 (n - 5,5), June 1994 (n =5,5), and July 

1995 (n = 5,5) (**p 50.05; ***p 50.01) . 2-8 

Mean abundance (% or no./0.25 m2) of important epibiota at Northwest 

Bay lower rocky stations, July 1995. 2-9 

Summary of littleneck clam mark/recovery experiment at Outside Bay 

and Block Island sites. 3-7 
1995 Summer Monitoring 

CONTENTS continued 

List of Tables continued 

Table 3-2 

Table 3-3 

Table A-1 

Table A-2 

Table B-1 

Table B-2 

Table B-3 

Table C-1 

Table C-2 

Table C-3 

Recruitment of age 0 and 1 littleneck clams to experimental pots with % 

fines (1125p), TKN, and TOC. 3-12 

Mean abundance (no./0.009 m2 core) of macroinfaunal animals in 

experimental pots recovered in July 1995. 3-15 

Location, site, station, habitat type, and total height of all sampling 

1989-95. .................................................................................................................. A-1 

Water temperature (OC) and salinity (ppt) at sampling sites in Prince 

William Sound, July 1995. .................................................................................... A-6 

Rocky middle intertidal epibiota, July 1995. ...................................................... B-1 

Age and growth data from 1994-95 littleneck clam transplant 

experiment. .............................................................................................................. B-9 

Rocky lower intertidal epibiota, July 1995. ..................................................... B-29 

Sediment grain size distribution, total percent fines (r 125 p), total 

organic carbon (TOC), and total Kjehldahl nitrogen (TKN) from the 

initial test sediments used in the clam recruitment experiment, 1994- 

1995. ........................................................................................................................ C-1 

Sediment grain size distribution, total percent fines (I 125 p), TOC, and 

TKN from the sediments used in the clam recruitment experiment 

when recovered in 1995. .................................................................................... C-2 

Age and growth data from 1994-95 littleneck clam transplant 

experiment. ............................................................................................................. C-5 
CHAPTER 1 

INTRODUCTION 

GENERAL 

This document is the sixth annual progress report on studies designed to investigate the 

ecological implications of shoreline treatments on intertidal and shallow subtidal marine life 

of Prince William Sound, Alaska, following the March 1989 spill from the tank vessel Exxon 

Valdez. This program addresses two areas of great uncertainty and concern about the effect 

of oil on shorelines: 

1. The length of time required for oil-damaged ecosystems to recover. 

2. The effects of shoreline treatment methods on marine life and the extent to which 

treatment affects recovery. 

It is imperative that information regarding shoreline recovery from the Exxon Valdez spill 

and the various treatments applied be made available to decision makers before the next 

such incident occurs. This need to obtain and disseminate information is the general 

rationale for the present study initiated by the National Oceanic and Atmospheric 

Administration (NOAA) under Contract No.50ABNC-2-00050. Funding in 1995 was 

provided by NOAA and the Restitution Fund established as part of the settlement between 

the Exxon Valdez Oil Spill Trustees Council and Exxon. 

Several studies conducted shortly after the spill demonstrated the effects of highpressure hot-water treatment on shoreline marine life. Exxon-sponsored studies of the 

short-term effects of two different beach cleaning methods employed in 1989; the July 1989 

Omni-Barge test and the Corexit 9580 test (Lees et al. 1993), provide data that allow 

inference of the short-term effects of oiling and describe the short-term impact of hydraulic 

beach treatments. Both of these high-pressure hot-water washes clearly had si,onificant, 

similar impacts on intertidal assemblages that had survived extended exposure to heavy 

oiling. 

The 1990 NOAA biological studies in Prince William Sound (Houghton et al. 1991a,b) 

report conditions on rocky; boulder/cobble, and mixed-soft beaches and in adjacent 
1995 Summer Monitoring 

eelgrass beds in portions of the sound that were oiled, or oiled and high-pressure hot-water 

washed in 1989. Biological conditions on these beaches were compared to those on unoiled 

beaches of similar habitats. The conclusions were: 

Cl the effects of high-pressure hot-water washing remained evident in the biological 

assemblages 16 to 18 months after the spill, and 

a oiled beaches not treated in this manner were well on their way to recovery. 

Results of the 1991 and 1992 NOAA biological studies in Prince William Sound 

(Houghton et al. 1993a,b) show that 

infaunal and epibiotal assemblages that were not high-pressure hot-water washed, in 

most respects, resembled communities on beaches that were not oiled, and 

Cl effects of high-pressure hot-water washing were still evident in some intertidal 

assemblages 40 months after the spill. 

Additional conclusions in 1991 were that oiling and subsequent treatment may have altered 

the spawning cycle of mussels and the reproductive strategy of eelgrass. Continued 

bioavailability of hydrocarbons was shown in the bioaccumulation of polycyclic aromatic 

hydrocarbons (PAHs) in transplanted mollusks. PAH levels in mussels had declined by an 

order of magnitude in 1991 from those seen in 1990, however, and generally continued to 

decline in 1992. 

By 1993 (Houghton et al. 1994) most epibiota had rebounded at the oiled sites; 

abundances in many cases were higher on oiled sites than on unoiled sites. This was 

attributed to continued instability in populations of biological control species. The infauna 

at hot-water washed lower intertidal stations continued to display lower density, richness, 

and diversity than those at reference stations and at oiled but unwashed stations. This 

continued difference raised a concern that the hot-water washed stations are fundamentally 

different from the other station categories and may never support similar infaunal 

communities. 

In 1994 (Houghton et al. 1995) the mature rockweed community at the oiled rocky 

intertidal sites declined from its 1993 peak. The general reduction in the cover of Fucus at 

the oiled sites was not seen in the rockweed communities at the unoiled reference sites and 

appeared to reflect the widespread senescence of a single cohort of plants. Some 

components of the community showed a trend toward increased stability (littorines). Other 
1995 Summer Monitoring 

groups such as the limpets continued to increase in 1994, probably in response to the 

abundance of weakened rockweed plants. A major predator/prey association at the 

middle intertidal stations is that of the drill (Nucella spp.) and its prey (barnacles and 

mussels). Abundances of drills, barnacles, and mussels have shown wide fluctuations and 

cycling of abundance from year to year. Increased abundance of drills at certain stations in 

1994 was expected to result in decreased abundances of barnacles and mussels in 1995. 

SAMPLlNG OBJECTIVE AND APPROACH 

Obiectives 

The overall objectives of this study are: 

O To assess and .compare the impacts of oiling and shoreline treatment activities 

(specifically, effects of high-pressure hot-water washing) in important littoral 

, (intertidal and shallow subtidal) habitats in the sixth year following the spill. 

0 To evaluate rates of recovery over several years in areas receiving differing levels of 

oiling and treatment. 

For purposes of this study, "recovery" is defined as the return of the ecosystem to a state 

within the limits of natural variability (Gaming et al. 1984). Detailed information was 

obtained on the dynamics and ecological forces driving recovery at a relatively small number 

of carefully selected sites. Data reported herein were gathered in July 1995, more than six 

years after the initial spill. It is anticipated that similar studies in the future will continue to 

document long-term recovery processes. 

Funding levels in 1995 allowed only limited field sampling and limited interpretation of 

data generated. 

Avvroach and Fieldwork Accomvlished 

The field approach in 1995 involved examination of a limited spectrum of variables 

representative of the status of and trends in intertidal infaunal and epibiotal assemblages 

and species. The intent was to continue the collection of data covering potential responses 

of a range of biological indicators to hydrocarbon contamination and to various 

disturbances caused by shoreline treatment. The data were used to compare the effects of 

hydrocarbon contamination and shoreline treatment and to compare rates and patterns of 

recovery in treated and untreated areas. The components examined in 1995 were: 
1995 Summer Monitoring 

Quantitative studies of epibiota (those species living on the substratum surface) 

abundance and relative cover at selected rocky intertidal sites. 

Collection of core samples for archiving and later analysis of intertidal infaunal 

assemblage characteristics for comparisons with data from previous years. 

Continuation of photographic record at selected sites. 

Retrieval of experiments started in 1994 designed to investigate factors influencing 

littleneck clam (Protothca staminea) recruitment, growth, survival, and bioavailability 

of hydrocarbons. Experiments involved a coordinated series of mark/recapture 

transplant experiments and a settling experiment involving selected sediment 

treatments. 

Collection of samples for analyses of grain size, total organic carbon (TOC), total 

Kjeldahl nitrogen (TKN), and PAHs in surficial sediments and PAHs in Protothaca 

staminea and Mytilus cf. trossulus. 

Intertidal sampling was conducted from July 11 to July 16,1995, 'with a single vessel and 

crew. About 36 person-days were expended in collecting 274 samples of all types. 

Epibiotic quadrats were examined at 18 rocky stations (Table 1-1). Ten sediment cores 

were collected at nine lower intertidal mixed-soft stations; five samples were archived for 

later infaunal analyses, and the remaining five samples were analyzed for grain size 

distribution. TOC/TKN analyses were conducted on samples composited from the area 

sampled for grain size. At contaminated lower mixed-soft sites, 17 sediment PAH samples 

were collected. Mussel tissue samples were collected at 16 stations for tissue hydrocarbon 

analyses. 

Specimens of individually tagged Nucella, originally released in 1991, were collected and 

measured on an as-time-allowed basis. Tagged Nucella were recovered at Bass Harbor, 

Outside Bay, Crab Bay, and Northwest Bay Rocky Islet. 
1995 Sunimer Monitoring 

Table 1-1. Intertidal rocky stations sampled in 1989-95 by oilingltreatment category. * 

Q) Q) 0 r m 

Degree of & - 

s Elevation CategorylStation oiling e E $ $ -, 4 3 

Upper Category 1 

Bass Harbor 

Eshamy Bay 

Hogg Bay Category 2 

Herring Bay 

Outside Bay 

Snug Harbor 

Category 3 

Mussel Beach S 

NW Bay lslet 

Block Island 

Elrington East 

Mussel Beach N 

Elrington Islet - N 

Elrington Islet - VI 

Elrington Islet - E 

None 

None 

None 

xxxxx 

XXX X 

xxxxx 

Heavy 

Light 

Heavy 

xxxxx 

xxxxx 

xxxxx 

Heavy 

Heavy 

Heavy 

Heavy 

Heavy 

Heavy 

Heavy 

Heavy 

xxxxx 

xxxxx 

X X 

X X XX 

X X X 

X X XX 

X 

XXX 

X X 

X X 

X X 

Middle Category 1 

Crab Bay 

Eshamy Bay 

Hogg Bay Category 2 

Herring Bay 

Outside Bay 

Snug Harbor 

Bay of Isles 

NW Bay W. Arm 

Category 3 

Block Island 

NW Bay lslet 

NW Bay W. Arm 

Elrington East 

Elrington West 

Mussel Beach N 

None 

None 

None 

X XXXXXX 

XXXXXX X 

X XXXXXX 

Heavy 

Light 

Heavy 

Light 

Moderate 

XXXXXXXX 

X XXXXXX 

XXXXXXX 

X XX X X X 

X X 

Heavy 

Heavy 

Moderate 

Heavy 

Heavy 

Heavy 

XXXX 

XXXXXXXX 

X X X 

X 

X 

X X XX 

X X XX 

X X XX 

X X 

X X 

XXX 

Lower Category 1 

Crab Bay 

Hogg Bay Eshamy Bay 

Category 2 

Snug Harbor 

Outside Bay 

Category 3 

NW Bay lslet 

Elrington East 

Elrington West 

Mussel Beach N 

None 

None 

None 

X X X X X XXX 

X X X X X X X 

XXX X XXXX 

Light 

Light 

X X X X X XXX 

X X XXXX XXX 

Heavy 

Moderate 

Moderate 

Moderate 

XXXXXXX X X XX 

X X 

X X 

XXX 

Category 1 = Unoiled; Category 2 = Oiled, untreated; Category 3 = Oiled, treated with hot water. Note: Sta 

categorized as oiled and treated are known to have been treated with some form of hot-water washing. 

** There is uncertainty regarding treatment history at this site; thus it was not included in any category analysc 
1995 Summer Monitoring 

Containers for the clam recruitment experiment were recovered at three sites. There were 

44 cores collected from the experimental pots. Each core was sorted and the infauna, 

except littleneck clams, identified to major taxonomic group (phylum or class) and counted. 

Young-of-the-year littleneck clams were counted and measured. Grain size samples were 

analyzed from each experimental unit, and a TOC/TKN sample was analyzed from each of 

the three lots of sediments used at a site. 

Tagged and untagged clams were recovered from six buried wooden quadrats at Block 

Island for age and growth analyses. At the Outside Bay reference site, two of the three 

quadrats were disturbed or lost as a result of a shift in over-the-beach drainage from a 

nearby lagoon. The area was searched for marked clams and a partial recovery was made. 

Sediment samples were collected for PAH analysis from each of the quadrats at the Block 

Island site. 

Hmotheses Tested 

Three treatment categories were defined at the beginning of the 1990 study: Category 1 

(moiled), Category 2 (oiled, but untreated or moderately treated), and Category 3 (oiled, 

treated with high-pressure hot-water wash Within each of these treatment categories, 

multiple sites were sampled in each year to provide replication for statistical testing. Based 

upon the stated study objectives, several previously formulated null hypotheses were tested 

to evaluate the continued effects of oiling and shoreline treatment on the intertidal 

assemblages in selected habitats: 

la. Relative cover of dominant algal taxa does not differ among site categories. 

lb. Abundance (density or percent cover) of dominant epifaunal species does 

not differ among site categories. 

2. There is no difference in the nature of (trends in) recovery between site Categories 2 

and 3. 

SAMPLING DESIGN 

A stratified random sampling design was used in all years to assess important intertidal 

assemblage and population (individual taxa) characteristics. Sampling was structured 

following Zeh et al. (1981) to obtain statistically reliable estimates of density or cover of 
1995 Summer Monitoring 

macrobiota inhabiting the surface (epibiota) and, where possible, the subsurface (infauna) 

within important life zones and typical habitats. 

The intertidal sampling effort was initially stratified according to three habitat types 

important in Prince William Sound: 

1. Sheltered rocky habitats-Intertidal substratum composed primarily of bedrock or 

very large boulders (50 centimeters [an] or larger). 

2. Boulder/cobble habitats-Exposed beaches with nearly 100 percent cover by 

rounded cobbles and boulders ranging from 10 to 50 cm. Some larger materials 

and/or bedrock outcroppings were occasionally present. 

3. Mixed-soft habitats-Typically a mixture of silt, granules, and pebbles with varying 

amounts of cobbles (5 to 25 cm) or boulders (25 to 50 cm). 

Sheltered (low energy) rocky and mixed-soft sites were initially included for two 

reasons: 

1. their biological productivity is high, and 

2. their low energy regime reduces the rate of natural weathering of oil (Jahns et al. 

1991; Michel et al. 1991). 

In 1995 sampling was conducted at 18 rocky sites (Table 1-1) and 9 mixed-soft sites (Table 

1-2). None of the exposed boulder/cobble sites sampled in earlier years were revisited in 

1995. 

To represent important life zones (i.e., to further stratify the sampling), three elevations 

(stations) were typically sampled for epibiota at each site: 

1. near the upper limit of attached macrobiota, 

2. in the upper portion of the broad rockweed-dominated zone, and 

3. along the lower edge of this rockweed zone. 
1995 Summer Monitoring 

Table 1-2. Intertidal infauna stations sampled in 1989-95 by oilingltreatment category. 

Elevation Category/Station 

Upper Category 3 

Sleepy Bay 

Middle Category 1 

Crab Bay 

Sheep Bay 

Outside Bay 

Category 2 

Snug Harbor 

Mussel Beach South 

Crafton lsland 

Category 3 

NW Bay W. Arm 

Shelter Bay 

Sleepy Bay 

Block lsland 

Lower Category 1 

Crab Bay 

Sheep Bay 

Outside Bay 

Bainbridge Bight 

Category 2 

Herring Bay 

Bay of Isles 

Snug Harbor 

Block lsland 

Mussel Beach South 

Ingot lsland 

Crafton lsland 

Category 3 

NW Bay W. Arm 

Shelter Bay 

X X 

XXX 

X X X 

X 

XXX 

X X 

X 

X X X X XX 

X X X X XXX 

X X XXXX X X XX 

XXXXXX 

XXXXXXXX X X XX 

X X X X X 

XXXXXXX X X XX 

XXXX X X XX 

X X X X X X X XX 

X X X X 

X X X X 

X X XXXX X X XX 

XXXXXXX X X XX 

Sleepy Bay x x x xx 

Elrington West xxx 

' Category 1 = Unoiled; Category 2 = Oiled, untreated; Category 3 = Oiled, treated with hot water. Note: 

Stations categorized as oiled and treated are known to have been treated with some form of hot-water 

washing. 
1995 Summer Monitoring 

Thus, in the terminology of this study a "location," such as Snug Harbor, can have both 

rocky and mixed-soft "sites," and each site can have up to three "stations" to represent 

different intertidal zones (Figure 1-1). Infauna was typically sampled only at lower 

elevation stations at mixed-soft sites. At each station, sampling was conducted at points 

along a transect line laid parallel to the waterline along the beach contour. Detailed 

descriptions and discussions of the sample design employed have been provided in the 

1991 and 1992 reports (Houghton et al. 1993a,b). 

SITE CLASSIFICATION, OILING, AND TREATMENT HISTORY 

About 570 kilometers (lun) of shoreline in Prince William Sound received sufficient oiling 

to require some form of shoreline cleanup or treatment in 1989 (Harrison 1991). Intensive 

efforts were made to verify the treatment history for each of the sites in this study (see 

Appendix Table A-1 in Houghton et al. 1993a). Information used to document the site 

designations was compiled from Exxon and State of Alaska records of treatments applied 

to various "beach segments" and from conversations with knowledgeable personnel in the 

field during 1989 (e.g., the authors, NOAA personnel, and field bosses for specific 

locations). Each site sampled in the present study typically occupied only about 50 meters 

(m) along a given beach and represents only a small fraction of the shoreline segment in 

question, which could range from a few hundred meters to several kilometers long. 

For statistical testing and qualitative discussion purposes, sites or stations within each 

habitat type were assigned to one of three categories to represent the range of possible 

stresses experienced in 1989. Stations at a given site may or may not be classified in the 

same category, depending on the site's known treatment history. Stations were classified as 

Category 1,2, or 3 based on available information about habitat disturbance from oiling and 

high-pressure hot-water treatment. Replicate stations were assigned to the following three 

site categories: 

Category 1: Unoiled in 1989-No significant oiling or treatment reported; 

considered reference stations. 

Category 2: Oiled in 1989-Untreated (set aside) or treated with cool-water 

flushes in 1989 and/or bioremediation in 1989,1990, or 1991. 

Category 3: Oiled in 1989-Treated with high-pressure hot-water wash(es), most, 

if not all, were also bioremediated in 1989, 1990, and/or 1991. 
1995 Summer Monitoring 
1995 Summer Monitoring 

Some sites or stations (Northwest Bay Islet and West Arm mixed-soft) were sampled in 

1989 before and after treatment and thus effectively moved from Category 2 to Category 3. 

These instances are noted in the appropriate data presentations. 

Each intertidal station was classified as to the degree of oiling experienced in 1989. 

Because oiling was typically very uneven vertically over the intertidal zone and upper 

elevations were much more heavily oiled, there is little point in mandating the same oiling 

classification for all stations (elevations) at a site. Moreover, the width of the oiled band on 

a shoreline has little effect on the specific intertidal assemblage at a station; what is 

important is the specific degree of oiling to which the plants and animals at that station are 

actually exposed (cf. Page et al. 1995). 

The following oiling classifications were used in this study: 

Unoiled-No area of continuous oiling present at any time in 1989. Some sheens 

may have been present on adjacent waters. In 1990 no oiling was present except for 

possible widely scattered tarballs or spots of indeterminate origin. 

Lightly oiled-Patches of oiling in 1989 with fresh oil, mousse, or tar; cover generally 

less than 50 percent, or large areas of continuous sheen present on the beach. Little 

if any oil was visible in 1990. All stations at a site reported to have been oiled were 

considered to have been at least lightly oiled, even if no evidence of oil was gathered 

from that elevation. 

Moderately oiled-Near-continuous oiling in 1989 with fresh oil, mousse, or tar; 

cover often exceeding 50 percent and approaching 100 percent in some areas but 

with relatively thin sheens; few areas of thick deposition (i.e., several millimeters 

(mrn) or more). Usually some oil remained in these areas in 1990 in the form of dry 

tar crusts on upper rock surfaces or light sheens within soft sediments. 

Heavily oiled--Continuous oiling in 1989 with fresh oil, mousse, or tar; cover 

approaching or reaching 100 percent; some thick deposits (i.e., several mm or more). 

Considerable oil generally remained in these areas in 1990 in the form of dry tar 

crusts on upper rocks or sheens and moist tar spots within soft sediments. 
1995 Summer Monitoring 

THE STUDY AREA 

Prince William Sound is a protected fjord and estuary system located on the southcentral coast of Alaska (Figure 1-2). Wave action from North Pacific storms is blocked by 

the outer line of islands. The winds, however, are only minimally ,abated by the low-lying 

peaks of those islands. This topography generates storm seas and chop that strike exposed 

shorelines with high-intensity wave action during storm events. Within embayments, wave 

energy may be minimal despite high wind forces because of limited fetch and frequent shifts 

in wind direction (Bascom 1964; Lethcoe and Lethcoe 1989). Fetch at specific locations 

within Prince William Sound, including several sites in this study, is provided by Michel and 

Hayes (1991). Tides are of the mixed semi-diurnal type; mean tide level is about 1.8 m, and 

extreme range is more than 5 m. 

The study area encompassed most of central and southern Prince William Sound from 

Sheep Bay on the eastern mainland to Eshamy Bay and Bainbridge Passage on the western 

mainland (Figure 1-2). The sampling focused on the chain of islands stretching from Naked 

Island (in the central sound), south-southwest through the Knight Island group, to the 

islands protecting the southwest entrances to the sound. This portion of the sound lay in 

the path of movement of oil from the Exxon Valdez and many beaches on these islands were 

oiled. 

Unoiled beaches in Prince William Sound support biological communities relatively 

specific to and characteristic of a given habitat type and range of tidal elevation. Within 

these communities there are usually several species that, because of their abundance and/or 

ecological roles (e.g., as an effective grazer or predator), exert a strong influence on other 

kinds of organisms found in the community. Throughout this report these taxa are termed 

cornunity or assemblage "dominants." 

REPORT ORGANlZATlON 

This report is organized into several chapters, each of which reports on methods used 

and results of specific aspects of the study. Because this is considered a data report rather 

than an interpretive report, emphasis is placed on tabular and graphical data presentations 

and narrative discussion of the data is limited. Chapter 2 reports on intertidal epibiota and 

associated physical and water quality measurements; Chapter 3 contains results of mollusk 

studies; Chapter 4 briefly discusses major findings and conclusions; and Chapter 5 provides 

references for literature cited and acronym identification. 
@ Sampling Locations 

(Core program biological sampling locations are shown in bold.) 

Figure 1-2. Prince William Sound study areas and sampling locations (asterisks). Sampling locations for 1994 are 
1995 Summer Monitoring 
CHAPTER 2 

INTERTIDAL EPIBIOTA 

INTRODUCTION 

Intertidal epibiota (the assemblage of plants and animals living on or attached to the 

substratum) was sampled in July 1995 at one or more elevations at ten rocky sites. A 

summary of selected 1989-95 intertidal sampling tasks and months of collection is shown in 

Appendix Table A-1; only sampling activities for 1995 are shown. A complete listing of 

sampling tasks completed in other years may be found in Appendix Table A-1 in Houghton 

et al. (199313). Latitude and longitude coordinates from a global positioning system (GPS) 

for each of the study sites are found in Appendix Table A-2 in Houghton et al. (1993b). 

Tidal elevations of stations at each study site are located in Appendix Table A-3 in 

Houghton et al. (199313). 

Field sampling of epibiota was conducted by intertidal ecologists with many years of 

experience in the taxonomy and natural history of Alaskan intertidal organisms. Some 

qualitative observations of trends or patterns observed during field surveys are reported on 

the basis of this experience without quantitative measurements or without demonstration of 

statistical significance. 

METHODS 

Water Quality 

Water temperature and salinity were measured with a YSI33 meter at six locations 

visited in July 1995 (Appendix Table A-2). The probe was gently lowered to about 0.3,1.8, 

or 2.4 m, below the surface of the water. Water temperature (1-O.l°C) and salinity (parts 

per thousand [ppt]) were read directly off the meter. 

Epibiota 

The abundance of epibiota was measured in July 1995 at one, two, or three elevations on 

rocky substrata (Table 1-1). Five or ten 0.25-m2 quadrats were sampled on 30-m sampling 

lines (transects) oriented along the beach contour. Quadrats were repositioned at the same 

orientation as those previously sampled with the aid of previously placed rebar stakes, 
1995 Summer Monitoring 

spikes, or epoxy markers. Where possible, the position of a quadrat was adjusted by 

referring to photographs taken during previous surveys. 

Prior to sampling, each quadrat was photographed with a label showing the site, date, 

and quadrat number. Most taxa were identified by biologists in the field. Problematic taxa 

were collected (from outside the sample area, if possible) for cross-comparison among 

investigators or for identification on board the support vessel or in the laboratory. 

Biological variables measured or estimated included algal cover (percent by taxon) and 

numbers or percent cover of major epibenthic fauna. Relative cover estimates for biota, 

substratum type, and oiling were based on visual examination of the tops, sides, and 

overhangs within a quadrat, but rocks fist-size and larger were not 'overturned. Whenever 

oil was found, a subjective description of oiling in each quadrat and the percentage of oil 

cover found within the quadrat was recorded. 

Field QA/QC 

All members of the field sampling team discussed procedures for field sampling at a 

mobilization meeting aboard each vessel before sampling to ensure that everyone 

understood the field methods to be used and that these methods were followed 

consistently. This common understanding, along with the use of the same personnel, 

maximized consistency with procedures used in previous years. 

Several checks were made prior to data collection in the field. Quadrats sampled at 

each location were checked against a master list of stations, dates of previous sampling, 

and quadrats that had previously been sampled destructively and nondestructively since 

1989. This check precluded resampling an area previously sampled destructively. Notes on 

the orientation of the station line and any deviations in the previous samplings were also 

checked. 

Some of the header information required on the data sheets (including location, 

elevation, date, foot marker numbers of quadrats to be sampled, and sample identification 

[ID]) was filled out onboard the support vessel prior to sampling. The sample ID numbers 

consisted of an eight-digit designation composed of the year, month, day, and a unique 

sample serial number. The principal investigator checked these numbers against the 

computer logs to ensure that numbers were not duplicated. Members of the field team noted 

these numbers, along with the type of sample to which each was assigned, in their field 

notebooks for reference in the field. Filling out the computer sample ID log before sampling 

ensured that all desired sampling activities were accomplished at each location. 
1995 Summer Monitoring 

On the beach, data sheets were checked to be sure header information was correct. The 

time sampling began was entered, and the data recorder checked quadrat numbers against 

the master station list to be sure that the quadrat numbers sampled were correct for the 

elevation. One person laid the tape in the appropriate direction from the station origin 

stake and checked with the recorder to see if permanent quadrat locations lined up with 

markers. Deviations from previous samplings were noted on the data sheet. The initials of 

the recorder were placed at the top of the data sheet, and the initials of the quadrat 

enumerator were placed at the top of each data column. 

There was frequent cross-checking of taxonomic identifications and estimates of percent 

cover between quadrat enumerators. 

Invertebrate nomenclature generally followed Kozloff (1987), and algal nomenclature 

followed Gabrielson et al. (1989). Problematic species and unique fauna and flora were 

placed in plastic bags, labeled, and returned to the support vessel for identification or for 

preservation as reference or voucher specimens. When sampling was finished, the recorder 

checked to make sure that all header information was entered on the data sheet, and 

another person checked that all information was complete. A final review of the data 

sheets was made later onboard the support vessel and included checking of the sample ID 

numbers against those previously assigned. 

Statistical Analvses 

Inferential Statistics 

Various statistical analyses were applied to quantitatively describe the data (number of 

species, number of individuals, and percent cover by species) and evaluate the significance 

of the findings. Parametric and nonparametric tests were applied as appropriate to 

evaluate the significance of differences observed between station categories. In these tests 

the mean of all subsamples (replicates) at a given station was used to represent each 

variable; thus, n= the number of stations within that category where the variable in question 

was measured. 

For tests of category effects and site-to-site differences in intertidal epibiota and 

environmental variables, a critical value (alpha) of p = 0.1 was used. Eberhardt,and 

Thomas (1991) note that the alpha of 0.05 "automatically" selected by most ecologists may 

be inappropriate in some cases. Use of 0.1 allows that there is a 1-in-10 chance of falsely 

rejecting the null hypothesis ("no difference between site categoriesw---Type I error). If there 
1995 Summer Monitoring 

is a greater concern for falsely accepting a null hypothesis that is in fact false (i.e., failure to 

identify significant effects of oiling or treatment when they exist-Type I error), then a lower 

critical value may be justified. 

Eberhardt and Thomas (1991) note further that a disparity commonly occurs about 

probability values between analysts on opposing sides of a controversial environmental 

issue. Those wishing to show "no effect" may ignore Type I1 error and opt for a critical p 

value of 0.05 or even 0.01; those concerned with not missing an impact choose a higher 

probability value to reduce the Type 11 error. Therefore, the authors have considered 

probability levels of 0.1 or less to represent significant differences (i.e., to reject the null 

hypothesis) in most aspects of this study. Use of the randomization approach to analysis 

of variance (ANOVA) and t-testing (see below) allows computation of exact p values. 

Many trends are noted as differences in mean values where no probability value is given. 

These differences are considered biologically relevant even though they are not statistically 

significant, often because of the limited replication of stations within site categories. 

Differences described between site categories also have been tested between pairs of 

stations representing those categories, often with significant results because of the greater 

sample size available. 

Randomization Tests 

Enumeration data were first tested for significant category effects using a randomization 

ANOVA and then tested for significant differences between pairs of site categories with a 

2-tailed randomization t-test (Edgington 1987). Randomization tests are distribution-free 

statistical tests in which the data are repeatedly reassigned among and between treatment 

groups. First, a test statistic (e.g., t or F statistic) is computed for the initial data set. The 

data set is then randomly shuffled and the test statistic recalculated. Following a thousand 

or more passes of this iterative process, the proportion of random test statistics greater than 

or equal to the initial test value represents the exact significance of the results. All 

assumptions of normality, homogeneity of variance, and other characteristics of randomly 

sampled populations are not relevant, with one exception: that the data set truly represents 

the population of interest (i.e., is sampled randomly; Edgington 1987). 

Randomization ANOVA tests performed on epibiota (middle rocky stations) data 

collected in 1990 indicated that, for certain dominant taxa, there were significant category 

effects-that is, abundance varied significantly among treatment categories. Multiple 

comparison tests using the 1990 data (Houghton et al. 1991a) identified significant (p < 0.1) 
1995 Summer Monitoring 

differences in abundances of certain taxa between various permutation pairs of site 

categories. The same approach, ANOVA for category effects followed by t-tests for 

significance of differences between pairs of site categories, was applied in 1991 through 

1994. Because a main purpose of this study is to assess the degree of recovery occurring 

over time, it was considered important to continue to test for differences between pairs of 

site categories, even for taxa for which no experiment-wise category effect remained in 1991 

through 1995. It is recognized that such multiple comparisons have a statistical penalty in 

the true experiment-wise alpha (Type I error term): differences calculated to have an alpha 

of 0.1 in the multiple comparison randomization t-tests in fact represent differences that 

have a greater than 1-in-10 chance of occurring randomly. 

For epibiota, detailed abundance data (Appendix B) were used in calculations of total 

algal cover and total taxa present. Certain taxa were subsequently combined into higher 

taxonomic groups (e.g., all species of limpets into the Family Lottiidae) for ease of 

presentation (e.g., Tables 2-1 through 2-4) and for statistical testing. A randomization 

ANOVA was used to determine if a significant category effect existed and was followed by 

randomization t-tests for differences among station categories for dominant taxonomic 

groups. 

RESULTS AND DISCUSSION 

Physical Measurements 

Water temperature and salinity were measured at six locations. Lowest surface water 

temperature (lO.l°C) was recorded at Northwest Bay Rocky Islet. Highest surface water 

temperature was found at Eshamy Bay (13°C). Lowest subsurface water temperatures were 

found at Block Island and Northwest Bay Rocky Islet (10.3 and 10.4"C1 respectively). 

Highest subsurface water temperatures were found at Eshamy Bay and Snug Harbor 

(123°C). Highest salinity (29.6 ppt at 1.8-m depth) was measured at Outside Bay. 

Northwest Bay Rocky Islet had surface salinity of 29.0 ppt and the highest subsurface 

salinity (1.8-m depth) of 29.2 ppt. Lowest surface salinity (8.0 ppt at 0.3-m depth) was 

found at Snug Harbor. The low surface salinity was the result of the development of a 

freshwater lens during heavy rains. Subsurface salinity in Snug Harbor (1.8-m depth) was 

25.5 ppt. Oil cover remained at or near zero at all stations at all elevations in 1995. 
1995 Summer Monitoring 

Table 2-l. Mean abundance (%or no1025 25 )of important epibiota at upper rocky stations, July 1995 (*p5 0.10; **p 5 0.05). 

Encrusting brown algae 

Encrusting red algae 

Endodadiaceae 

Flagellifom brown algae 

Fucus gardneri 

Fucus gardneri (gerrnlings) 

Total Fucus 

Misc. Chlorophyta 

Misc. Cyanophyta 

Rhodomelaceae/Cryptosiphonia 

verrucaria spp. 

Total plant cover (%) 

No. of plant taxalquadrat 

No. plant Wsite 

Animals (% cover) 

Palanus glandula 

~lanus~Sernibalanus spp. 

Palanus/Semibalanus spp. (set) 

Chthamalus dalli 

Mytilidae (spat) 

Myfilus cf. trossulus 

Semibalanus balanoides 

Semibalanus cariosus 

Total barnacles 

Total animal cover (%) 

No. of animal taxalquadrat 

No. animal Wsite 

Animals (No1025 25) 

Ligia sp. 

Littorim scufulafa 

Littorim sifkana 

Linorina spp. ow.) 

Loltiidae 

Lottiidae ow.) 

Nucslla lima 

Pagum hirs~uswlus 

No. of animals/quadrat 

No. animal taxalquadrat 

No. animal taxalsite 

Dead organisms (Oh cover or no1025 25) 

&/anus glandula (dead) 

Mytius sp. (dead) 

Semibalanus belanoides (dead) 

Other (% cover) 

Rodc 

BoulderICobble 

GravelEand 

Oil cover 

Oil scale 

Water 

Number of stations 2 

Note: animals w/ means c 0.15 were hidden. 
1995 Summer Monitoring 

Table 2-2. Mean abundance (%or noJ025 in2 of impoltant epibiota at middle rocky stations, July 1995 (*p 5 0.10). 

Plants (% cover) 

~lachisk spp. 

Encrusting brown algae 

Encrusting coralline algae 

Encrusting red algae 

Endocladiaceae 

Filamentous brown algae 

Filamentous green algae 

Rageliiform brown algae 

Fucus gardneri 

Fucus gardneri (germlings) 

Total Fucus 

Gigartinawae 

Halosaccfon glandiforme 

Misc. Chlorophyta 

Misc. Cyanophyta 

Mlsc. Phaeophyta 

RhodomelaceaBICryptosiphonia 

Soranlhera ulvoidea 

Total plant cover (%) 

No. ct plant taxslquadrat . No. plant Wslte 

Anlmals (77 cover) 

Balanus glandula 

Balanus/Semibalanus spp. (set) 

Chthamalus dalli 

Mytilidae (spat) 

Mytilus d. trossulus 

Semibalanus Manoides 

Semibalanus cariosus 

Siphonaria thersites, eggs 

Total barnacles 

Total animal cover (%) 

No. of anlmal Wquadrat 

No. anlmal taxalslte 

Anlmals (Nol0.W m2) 

Gnorimosphaeroma oregonensis 

Lacuna spp. 

Littorins scutulata 

Littorina sitkana 

Littorina spp. Quv.) 

Lottiidae 

Lottiidae (juv.) 

Nemertea 

NuceNa lamellma 

Nucella lime 

Onchidella borealis 

Pagurus hirsutiuscuius 

Siphonaria thersites 

No. of anlrnalsD25m2 

No. anlmal Wquadrat 

No. anlmal Wsite 

Dead organisms (%cover or no1025 m2) 

Fucus gardneri (dead) 

Balanus glandula (dead) 

Balanus/Semibalanus spp. (dead) 

Chthamalus dalli (dead) 

Myfils sp. (dead) 

Semibalanus balanoides (dead) 

Other (% cover) 

Rocic 

Boulder/Cobble 

GraveVSand 

Mud 

Water 

Number of statlons 2 3 3 

Note: animals w/ means c 0.15 were hidden. 
1995 Summer Monitoring 
1995 Summer Monitoring 

Table 2.4. Mean abundance (% or noJ0.25 m2) of important epibiota at Northwest Bay 

Islet lower rocky station, July 1995. 

Category 3 

Lumped taxon Mean 

Plants (% cover) 

Elachista spp. 1.50 

Encrusting brown algae 5.70 

Encrusting coralline algae 1.40 

Encrusting red algae 7.90 

Endocladiaceae . 0.30 

Filamentous brown algae 2.55 

Filamentous green algae 5.05 

Filamentous red algae 0.70 

Flagellifom brown algae 0.60 

Foliose green algae 1.75 

Fucus gardneri 57.10 

Fucus gardneri (geimlings) 1.30 

Total Fucus 58.40 

Gigartinaceae 2.55 

Halosaccion glandiforme 1.20 

Misc. Chlorophyta 0.15 

Misc. Cyanophyta 0.15 

Misc. Phaeophyta 0.15 

Palrnaria spp. 0.20 

Rhodomelaceae/Cryptosiphonia 9.85 

Total plant cover (%) 100.35 

No. of plant taxadquadrat 32.00 

No. of plant taxdsite 22.00 

Animals (% cover) 

Balanus glandula 0.30 

Balanus rostratus 0.30 

BalanudSernibalanus spp. (set) 0.75 

Chtharnalus dalli 0.90 

Encrusting bryozoan 0.30 

Mytilidae (spat) 0.40 

Total barnacles 2.40 

Total animal cover (%) 3.30 

No. of animal taxalquadrat 3.1 0 

No. of animal taxdsite 9.00 

Animals (noJ0.25m2) 

Spirorbidae 0.30 

Lacuna spp. 0.50 

Littorina scutulata 3.10 

Littorina sitkana 0.40 

Littorina spp. ow.) 0.70 

Lottiidae (juv.) 105.20 

Margarites spp. 0.40 

Nemertea 0.40 

Pagurus hirsutiusculus 14.50 

Pisaster ochraceus 0.20 

Pycnopodia helianthoides 0.20 

No. of animalslquadrat 126.35 

No. of animal taxalquadrat 6.00 

No. of animal taxdsite 15.00 

Dead organisms (% cover or noJ0.25 m2) 

Fucus gardneri (dead) 0.15 

BalanudSernibalanus spp. (dead) 0.55 

Chtharnalus dalli (dead) 0.15 

Hiatella arctica (dead) 0.40 

Mytilus sp. (dead) 1.80 

Other (%cover) 

Rock 97.50 

Boulder/Cobble 0.60 

Gravelisand 1.70 

Mud 0.20 

Number of stations 1 
1995 Summer Monitoring 

Biological Conditions 

Ten rocky sites were sampled at one or more elevations in July 1995 (see Table 1-1). The 

rocky sites included three Category 1, fox Category 2, and four Category 3 sites. Detailed 

data on taxon abundances by individual station are provided in Appendix Tables B-1 

through B-3. 

Upper Rocky Stations 

Upper rocky stations were examined at eight sites in July 1995. These included two 

Category 1 sites (Bass Harbor and Eshamy Bay) and three each at Category 2 (Herring Bay, 

Outside Bay, and Snug Harbor) and Category 3 (Block Island, Mussel Beach, and 

Northwest Bay Rocky Islet) sites. The dominant plants at upper rocky stations in all three 

categories of sites were rockweed and the lichen Vewucaria. The dominant animals were 

barnacles, especially Semibalanus balanoides and littorine snails, especially Littorina scutulata. 

Plant and animal cover was sparse. 

Significant category effects were found in two biological variables at upper rocky 

stations in 1995 (Table 2-1). The barnacle Semibalanus balanoides and limpets (Lottiidae) 

were both more abundant at Category 1 sites than at Category 3 sites. Littorines were more 

than two times as abundant, on average, at Category 1 and 2 upper stations than at 

Category 3 upper stations but variability was relatively high and the differences were not 

sigruficant. 

At upper rocky stations, rockweed (Fucus gardneri) was found at low abundance at all 

categories through 1991 (Figure 2-1, upper) reflecting the initial selection in 1989 of upper 

stations at the top of the obvious zone of attached macrobiota. By 1992 the mean percent 

cover of Fucus at oiled upper stations (both Category 2 and 3) began to increase markedly 

compared with Category 1 stations (Figure 2-1). Fucus cover at the Category 2 and 3 upper 0 

stations increased through 1993 (to 15.4 and 8.7 mean percent cover, respectively) then 

declined slightly in 1994 and 1995. The natural variation in cover for rockweed at the upper 

elevation in the study area from 1989 to 1995 ranged from 0.3 to 2.5 percent. This range of 

natural variation is defined as k3 standard errors around the mean for the annual means of 

the reference sites over the duration of the program and is shown on Figure 2-1. Average 

cover for rockweed at Category 1 upper stations demonstrated an increase above this range 

in 1995 as it returned to near the cover observed for the reference sites in 1989. Rockweed 

cover at Category 2 and 3 sites has averaged above the natural range of cover observed at 
1995 Summer Monitoring 

Category 1 sites continuously since 1992, demonstrating that the initial selection of the 

upper elevation stations was inconsistent. 

Fauna associated with the Fucus coxlmunity, such as the periwinkles Littorina scutulata 

and L. sitkana, showed somewhat similar changes in abundance to rockweed during this 

period but generally demonstrated greater similarity among categories than rockweed and 

relatively high consistency in temporal patterns for abundance between species. Both 

species have exhibited substantial variability in abundance over the duration of the program 

(Figure 2-2). The apparent upper limit of attached macrobiota had been influenced 

(lowered) by oiling and treatment effects in 1989. 

The mean density of Lottiidae (limpets) at Category 1 sites was consistently greater 

than the density at the oiled sites through 1992 (Figure 2-3). The sharp decline in 

abundance for Category 1 in 1993 reflects, at least partially, that the single upper Category 

1 station (Eshamy Bay) sampled that year has consistently had lower densities of Lottiidae 

than the other Category 1 upper stations. Lottiidae abundance at Category 2 and 3 sites 

exhibited strong similarity from 1989 through 1995 except for a slight divergence in 1995. 

Only after 1993 did average abundance for lottiids rise to within the normal range of 

abundance observed at the Category 1 upper stations. Average abundance at Category 1 

upper stations was considerably more variable than in the other upper stations, both among 

stations during a survey and over the duration of the program (Figure 2-3). 

Middle Rocky Stations 

Middle rocky stations were examined at eight sites in July 1995. These included two 

Category 1 sites (Crab Harbor and Eshamy Bay) and three each at Category 2 (Herring Bay, 

Outside Bay, and Snug Harbor) and Category 3 (Block Island, Northwest Bay Rocky Islet, 

and Northwest Bay West Arm) treated sites. Plant cover at middle rocky stations in all 

three site categories was strongly dominated by rockweed. The dominant animals were 

barnacles, especially Semibalanus balanoides; limpets; littorine snails, especially Littorina 

sitkana; and the hermit crab Pagurus hirsutiusculus. Plant cover was moderate but animal 

cover was sparse. The primary predators at the middle rocky stations, the drills Nucella 

lima and N. lamellosa, feed mainly on barnacles and mussels; of these two species, the latter 

is more abundant. 
1995 Summer Monitoring 

30 

- Category 1 

25 - - --P- Category 2 

- 

20 L - Category3 - 

- I 

- 

15 - 

- 

10 - 

- 

Cat 1 n= 3 3 3 2 3 3 1 3 2 

Cat 2 n= 3 3 3 3 3 3 3 3 3 

Cat 3 n= 2 2 2 3 3 3 3* 3 3 

1989 1990 1991 1992 1993 1994 1995 

* Includes estimated Fucus cover for NW Bay Rocky Islet determined from quadrat photographs. 

45 

-D- Block (Cat 3) 

-I- Mussel (Cat 3) 

- 

20 { 

- 

15 -5: 

- 

Figure 2-1. Mean percent cover (kl SE) of Fucus from upper rocky stations, b.y category and 

from selected upper rocky stations 1989-95. Number of stations sampled (n) for 

each category shown below axis. Gray dashed lines represent range of natural 

variation (k3 SE around mean of annual means( of reference site.) 
1995 Summer Monitoring 

---a--- Category 1 

-9- Category 2 

L. sitkana 

Cat 1 n= 3 3 3 2 3 3 1 3 2 

Cat 2 n= 3 3 3 3 3 3 3 3 3 

Cat 3 n= 2 2 2 3 3 3 2 3 3 

1989 1990 1991 1992 1993 1994 1995 

Figure 2-2 Mean abundance (kl SE) of littorine snails from upper rocky stations, by category 

1989-1 995. 
1995 Summer Monitoring 

-* I. 

\ 

I / \ / 

, 0 

0 

0 

0 

0 - 0 

0 

. 0 

I 0 

w 

u 

Bbb 

1111 11 I1 IIII)IIII 

0 0 0 0 0 

(0 V) d (3 cu f3 
1995 Summer Monitoring 

Only one biologically and statistically significant category effect was observed at the 

middle stations. Numbers of plant taxa were significantly lower at Category 1 sites than at 

Category 3 sites (Table 2-2), a difference not seen in prior years. 

In 1995, rockweed continued a trend predicted in 1990 and first observed in 1994. 

Mean cover of Fucus declined in all three categories from the cover seen in the original 

surveys in 1989 until at least 1991 or 1992 (Figure 2-4). Lowest cover was observed in July 

1990 at Category 3 sites and in May 1991 at Category 2 sites. Starting in 1991, Fucus cover 

at the oiled middle stations increased through 1993 until mean percent cover exceeded the 

mean for the Category 1 sites. Rockweed apparently lives four to five years. Because of the 

severity of the shoreline treatment, rockweed populations at Category 3 sites were severely 

damaged, leaving a considerable amount of rock surface available for recruit-ment (Figure 

2-5). As a consequence, recruitment of germlings was heavy in 1990 at all Category 3 sites 

and some Category 2 sites. At those sites, the rockweed populations became dominated by 

a single year class. Thus, four to five years later, starting in 1994, Fucus cover decreased at 

Category 2 and 3 sites, probably reflecting a general senescence of the mature rockweed 

community at these stations (Figure 2-4). Fucus cover at the moiled Category 1 sites 

fluctuated moderately over that period, but the long-term trend appears to be relatively 

stable compared to the trends found at the oiled sites. Fucus germling recruitment at the 

Category 1 middle stations has varied over time but has averaged approximately one 

percent cover during the seven years of the study (Figure 2-5). The higher cover by mature 

Fucus at the oiled sites in 1993 is attributed to the greater recruitment and increased survival 

of Fucus germlings at Category 2 and 3 sites in 1990 and 1991. Abundance of Fucus 

germlings achieved a hiatus in 1992, but since then cover has increased continuously, most 

notably at Category 2 sites in 1995. Variability in cover by Fucus germlings has been 

substantially less at Category 1 sites than at Category 2 and 3 sites, where annual averages 

have been outside the normal range for Category 1 sites the majority of the time (Figure 2-5). 
1995 Summer Monitoring 
1995 Summer Monitoring 

CCC 

QQQ 

000 
1995 Summer Monitoring 

Average abundance for both species of littorines decreased at Category 1 middle 

stations in 1990 and 1991; minimum density observed for the program was observed in 

1991 (Figure 2-6). Since then, fluctuations in density have generally remained within the 

normal range of variation observed for the entire program for the respective species. In the 

case of Littorina sitkana, fluctuations for all three treatment categories have been quite similar 

since 1991. For L. scutulata, fluctuations for Category 2 and 3 sites have been similar since 

1991, but abundance at Category 3 sites has been substantially higher than at the other sites 

and varied dramatically. Littorines have been declining slightly at Category 2 and 3 sites 

since 1993 (Figure 2-6). 

Average abundance of limpets (adults and juveniles) has increased appreciably since 

1989 in all treatment categories. Limpets at Category 1 middle stations have gradually 

increased by nearly 100 percent since 1989; this increase appears to define the range of 

natural variation for the reference sites. Limpet abundance at Category 2 middle stations 

approximated these changes very closely until 1992. Since then limpet abundance at these 

stations has exceeded abundance at Category 1 sites by about 30 percent. Average limpet 

abundance at Category 3 middle stations has increased from virtually none in 1989 to over 

50/m2 in 1995. In 1995, Category 3 middle stations had higher densities than Category 1 or 

2 sites, a complete turnaround in the situation from 1989 through 1991 (Figure 2-7). 

With the exception of Category 3 middle stations in June and September 1989, mussel 

cover at mid intertidal rocky sites has been relatively well synchronized (Figure 2-8). 

Moreover, average densities have fallen within the normal range for the Category 1 sites. In 

relative terms, densities have oscillated across a range of 300 to 400 percent over the course 

of the program but, except for the very low densities at Category 3 stations in 1989, cover 

has remained fairly stable at about 1 to 8 percent. The period of the oscillation appears to 

exceed seven years. Exceptions to this pattern were found at Outside Bay (Category 2; 

Appendix Table B-2) and Northwest Bay West Ann (Category 3; Table 2-3) where mussel 

populations have remained low since 1989. 
1995 Summer Monitoring 

200 

100 

50 

0 

Cat 1 n= 

400 - 

L. scutulata 

- 

- 

350 -I 

- 

- 

300 -1 

- - 

250 < 

- - 

Cat 2 n= 4 4 4 4 3 4 3 3 3 3 

Cat 3 n= 11 2 2 2 2 3 3 3 3 

1989 1990 1991 1992 1993 1994 1995 

Figure 2-6. Mean abundance (k1 SE) of littorine snails from middle rocky stations, by category 

1989-95. 

L. sitkana 

----0--- Category 1 

--V-- Category 2 

----CI-- Category 3 

T 
1995 Summer Monitoring 
1995 Summer Monitoring 
1995 Summer Monitoring 

With the exception of very low cover at Category 3 middle stations from 1989 

through May 1991, barnacle cover has remained generally within the normal range 

observed for the Category 1 middle stations (Figure 2-9). Fluctuations in barnacle cover 

do not appear to be synchronized, however. Barnacle cover at Category 2 middle 

stations has been somewhat more stable than at Category 1 middle stations that, in later 

years, has fluctuated about 400 percent. Since 1991, barnacle cover at Category 2 middle 

stations has consistently increased, whereas, it has decreased at Category 3 stations. 

Barnacle populations, severely impacted at Category 3 sites during treatment in 1989, 

rebounded in the summer of 1991 when a large set of the opportunistic barnacle 

Semibalanus balanoides contributed to a higher cover at Category 3 sites than at the 

Category 1 or 2 sites. 

Density of the drill Nucella at Category 1 middle stations has exhibited long-term 

cycles with a period of about five years during this program. It declined from 1989 to 

1991 at the Category 1 sites, increased considerably from 1991 through 1994, and then 

declined substantially in 1995 (Figure 2-10). This cycle probably reflects a response to 

combined changes in cover of mussels and barnacles, the favored prey of both species of 

Nucella. NucelZa abundance at Category 2 sites increased from 1991 through 1993 and 

declined in 1994, following a pattern similar to that shown by mussels (Figure 2-8). 

Nucella abundance at Category 3 sites peaked in 1992 and has then declined 

continuously through 1995. Over that period, barnacle cover (Figure 2-9) has declined 

consistently whereas mussel cover increased until 1994 and then declined substantially. 

Generally, Nucella density at oiled sites has remained either slightly below or in the 

lower half of the normal range of density and has been considerably less variable than 

has been observed at the Category 1 middle stations. 

Northwest Bay West Arm Middle Stations 

When first sampled in September 1989, the Category 3 middle station at the 

Northwest Bay West Arm rocky site had significantly greater oil cover and significantly 

greater cover by dead coralline algae (both p < 0.05) than did the adjacent (also oiled) 

reference site that did not appear to have been hot-water washed (Table 2-3). This, and 

the other patterns described below, suggest that the treatment was both ineffective at oil 

removal and immediately damaging to the epibiota. 
1995 Summer Monitoring 

I 
1995 Summer Monitoring 
1995 Summer Monitoring 

In an apparent reversal of previous trends, the number of significant differences between 

the two stations, which had decreased through 1993, increased in 1995 (Table 2-3). This 

reversal suggests some destabilization of the normal biological controls at the Category 3 

station, possibly as a consequence of the senescence of Fucus. It appears that full recovery 

may still be several years away. The degree to which differences are the result of slight 

differences in wave exposure at the two sites is uncertain but will become clearer over time. 

Algal cover has been dominated by rockweed (Fucus) since 1989 at the reference station 

and since 1990 at the Category 3 station. Total cover by algae and Fucus at the reference 

station remained relatively constant from 1989 through 1993 (Table 2-3; Figures 2-11 and 2- 

12). The slight decline in Fucus cover that began in 1993 led to a sharp die-off in 1994 

(Figure 2-12); Fucus cover seemed to stabilize in 1995. Total cover by algae and Fucus at the 

Category 3 middle station increased steadily after 1989 (based on photo documentation) 

and showed substantial recovery by July 1993 relative to the adjacent middle reference 

station. However, total algal cover has never been more than 65 percent of that observed at 

the reference station. Fucus cover at the Category 3 station declined consistently from 65 

percent in 1993 to 13 percent in 1995 because of the senescence of the dominant year class 

that had set as germlings in 1989 following treatment. 

The mean number of algal taxa at the reference station increased from 1989 through 

1993, possibly showing some recovery from effects of oiling but more probably associated 

with increasing taxonomic sophistication of the investigators (Figure 2-11). The number of 

algal taxa declined at the Category 3 station from 1991 to 1992 but increased again in 1993 

and stabilized until 1995. The difference in mean total number of algal taxa between the 

two stations had increased in 1992, a trend contrary to the recovery and probably the result 

of increased Fucus dominance that excluded some other species; this difference has 

diminished consistently since 1993 (Figure 2-11; Table 2-3). 

Patterns in cover by the opportunistic red alga Gloiopeltisfurcata have differed 

substantially between the two middle stations at the Northwest Bay West Arm rocky site. 

Gloiopeltis was significantly more abundant at the more disturbed Category 3 station in 1991 

but declined steadily with the increased Fucus cover until 1994. In contrast, cover increased 

at the reference station such that it was greater at the reference station than at the Category 

3 station in 1994 and 1995 (Figure 2-13). 
Figure 2-11. Mean percent total algal cover and total number of algal species' site from the Northwest 

middle rocky stations, 1989-95. 

- 

- 

- 

- 

& 

A 4 \ 

- 

0 h-----A8 

- 

- 

- 4 \ 

- \ 

- / 

- 

- A 

- 

- A 

- 

- 

- 4 

- 

- 

- 

- ,,,,, I,,,, 'I"" "II'Il~"'"""Il~IIll'"""~"liI"II"~"" "'"1'1""l"'
1995 Summer Monitoring 

0 0 0 

Co (D d (V 

0 

JaAos tuas~ad ueaw snmj 
Figure 2-13. Mean percent cover of total erect red algae and Gloiopeltis from the Northwest Bay West Arm 

rocky stations, 1989-95. 
1995 Summer Monitoring 

The cover of erect red algae other than Gloiopeltis has varied between 11 and 24 

percent at the reference station since 1989 (Figure 2-13). Until 1992, red algal cover was 

low (less than 5 percent) at the Category 3 station following treatment, but has climbed to 

about 12 percent in 1995. The saccate red Halosaccion glandiforme first appeared at the 

Category 3 station in 1994 and still remains significantly less abundant (p < 0.01) than at 

the reference station. 

Some of the dominant animals have shown signs of recovery at the Category 3 

middle stations between 1991 and 1995, but the patterns are not consistent or persistent. 

Densities of limpets at the two stations have consecutively converged and diverged 

since 1991, but both have increased about 30 percent over that period (Figure 2-12). The 

opportunistic barnacle S. balanoides remained essentially absent through 1994 at the 

reference site. Cover of S. balanoides precipitously declined from its 1991 peak at the 

Category 3 station (Figure 2-14); however, in 1995 cover increased substantially at both 

stations. The sharp decline in barnacles at the Category 3 station preceded a decline in 

numbers of the drill Nucella lamellosa. The large fluctuations in abundance of this 

predator and its principal prey at the hot-water washed station contrast sharply with the 

relative stability of these two species at the reference station, but the relatively low 

abundance of the barnacle at the reference site suggests that the barnacle is not important 

there and that the drill is probably targeting a suite of alternative prey (Figure 2-14). 

Abundance of both species of littorine snails has fluctuated wildly at both stations 

except for Littorina scutulata, which has remained consistently low throughout the 

program at the reference site (Figure 2-15). Four animal taxa showed statistically 

significant differences between the two stations in 1995 (Table 2-3). The periwinkle snail 

Littorina scutulata was significantly more abundant at the Category 3 station, whereas 

limpets (Lottiidae), the drill Nucella lamellosa, and the pulmonate snail Siphonaria 

thersites were significantly more abundant at the reference station. These patterns have 

been consistent over the period of the study. Since 1989, Siphonaria has been 

significantly more abundant at the reference stations in all six years that this site has 

been sampled. Limpets have been more abundant at the reference site and L. scutulata 

has been more abundant at the Category 3 site all years. 
OS-Z 

S. balanoides mean percent cover 

Nucella mean abundance per 0.25 m 
Figure 2-15. Mean abundance of Littorina sitkana and Littorina scutulata from the Northwest Bay West A

rocky stations, 1989-95. 
1995 Summer Monitoring 

Lower Rocky Stations 

The only lower rocky intertidal station sampled was the Category 3 station at 

Northwest Bay Islet, which was also the only Category 3 lower station sampled in 1994 

(Table 2-4). This limits analysis to only a description of the trends for dominant taxa. 

Fucus cover at the Northwest Bay Islet lower station was about 20 percent higher in 1995 

than in 1994. Coverage of the Rhodomelaceae/ Cryptosiphonia complex remained . 

virtually unchanged. This group of algae has remained severely depressed from its pretreatment levels. The fauna associated with the Fucus community, such as the littorines 

and Lottiidae, continued to be found at high densities at the Northwest Bay Islet lower 

station (Table 2-4). Lottiids nearly doubled in density, largely on the strength of juvenile 

recruitment. Two drills (one Searlesia dira and one Nucella larnellosa) were observed at 

this station in 1995. 
CHAPTER 3 

MOLLUSK STUDIES 

INTRODUCTION 

The effects of the spill and subsequent shoreline treatments on hardshell clams at lower 

mixed-soft stations have been investigated over the 1989 to 1995 period using three primary 

techniques: 

Excavating randomly placed 0.25-m2 quadrats each year, except 1993 and 1995, to 

evaluate densities of larger clams (e.g., > 5 mm) at lower elevation stations. 

Separating small clams from the infaunal cores at each station to evaluate 

recruitment. 

Transplanting clams experimentally in 1991, 1992-93, and 1994-95 to aid our 

understanding of the survival, growth, and uptake of hydrocarbons by the littleneck 

clam Protothaca staminea. 

An experimental clam and infaunal recruitment experiment also was conducted in 1994- 

95 to investigate causative factors limiting recruitment to treated and untreated beaches. 

Analyses were also conducted in 1993 of the histopathology and reproductive maturity 

of clams and mussels with different exposure histories (Brooks 1994). 

METHODS 

Field Transplant Experiments 

A littleneck clam transplant experiment was initiated in June 1994 to supplement 

information gained in similar experiments in 1991 to 1993. A total of 611 littleneck clams 

were collected from near the lower reference station at Outside Bay and approximately 162 

clams were collected from near the lower station at Block Island. Tag,@ng with a direct mark 

was done to permanently identify individual clams (e.g., Houghton 1973) so they could be 

measured at the be,@ning and the end of the experiment, increasing the statistical power of 

the results. Each clam was marked by engraving a number in the side of its shell with a 

Dremel tool; the number was inked in with a permanent marker and the mark was covered 

with clear nail polish or marine epoxy. Animals were held in fresh seawater for a maximum 
1995 Summer Monitoring 

of two days following marking before transplanting. During this holding period, water was 

changed several times a day. 

At the transplant site at Block Island, wooden quadrats (0.25-m2) were dug into the 

sediment flush with the sediment surface just below the existing lower intertidal transect. 

Six quadrats were randomly located on a transect established along the beach contour 

(Figure 3-1). Sediments within each quadrat were hand-dug to a depth of 10 to 15 cm to 

loosen the material for planting and to remove indigenous clams. Marked Outside Bay 

clams (a minimum of 80 clams of varying sizes (11.7 to 42.2 mm long)) were transplanted 

into each quadrat in ten equally spaced rows of eight clams. Use of 80 clams per quadrat 

made it easy to load clams into the quadrats and provided adequate numbers of clams for 

growth and survival studies. 

Similar marking and transplanting techniques were used to mark and replant 83 Outside 

Bay clams into one plot and to transplant 80 and 82 Block Island clams to each of two 

plots at the Outside Bay lower station for cross comparisons. 

All littleneck transplant quadrats were left in place over the winter and excavated and 

hand-sorted to remove tagged clams in July 1995. All marked clams recovered were 

retained and frozen for length and age analyses. 

Clam Aging Conventions 

Because erosion in the urnbonal region makes identification of -the first annulus difficult 

on older venerid clams, littleneck and butter clams were aged using a modification of the 

methods and conventions of Houghton (1973). Specifically, rings less than 2.5 mm long 

were not counted as annuli, and no first annulus was recorded as greater than 8 mm. When 

the first distinct ring was greater than 8 mm, this ring was assumed to be the second 

annulus, and the first annulus was recorded as 2.5 mm. In addition, the external sculpture 

was filed to help distinguish true annuli from disturbance checks. Total length and lengths 

of the last three annuli were measured to the nearest tenth of a millimeter. 
1995 Summer Monitoring 

Outside Bay 

0 

Lot 6 Lot 8 Lot 3 Lot 5 Lot 9 Lot 4 

Increasing PAH - 

Block Island 

Figure 3-1 Experimental design and number of clams transplanted and recovered in the 

1994-1995 littleneck clam transplant experiment. 
1995 Summer Monitoring 

Recruitment Experiment 

An experiment was begun in 1994 to test hypotheses regarding factors that appear to 

be limiting recruitment of littleneck and butter clams, Saxidomus giganteus, and 

infauna to beaches that were hydraulically washed. Experimental units consisted of 

perforated plastic flower pots filled with specified test sediments and set into the beach 

in question. Reciprocal sediment exchanges between sites with good and poor 

recruitment and detailed chemical and physical analyses of sediments were used to 

enhance our understanding of causative factors. Each experimental treatment was 

replicated five times at each test site. 

The following sediment treatments were established at: 

1. Northwest Bay West Arm (local, local with added silt fraction, Outside Bay). 

2. Block Island (local, Northwest Bay, Northwest Bay with added silt fraction). 

3. Outside Bay (local, Northwest Bay, Northwest Bay with added silt fraction). 

Sediment for the "added silt fraction" was obtained at about mean lower low water 

(MLLW) at the head of the lagoon on the north side of the isthmus separating Eleanor 

and Block islands. This sediment was a black mud with a high content of organic 

material. It was mixed about half and half with the Northwest Bay West Arm sediment 

to make up the material used in the "Northwest Bay with added silt fraction" test 

sediment. 

Test sediments were treated with hot, fresh water to kill existing infauna and each 

pot was filled and set in the beach at the lower tidal elevation. Samples of each test 

sediment were retained for analysis of initial grain size (Appendix Table C-1), PAH 

(Block Island treatments only), TOC, and TKN. The top flange on each pot was set flush 

with the ambient sediment surface and attached to a rebar stake with a plastic tie wrap. 

Replicates of different treatments were randomly interspersed at each site to rninirnize 

bias. 

In 1995 cores were taken of the undisturbed sediments within the recovered test pots 

(one per treatment) and field-sieved through a 1.0-mm screen. The residue was 

preserved in a 10 percent buffered formalin solution. Sediment samples from each pot 

were collected for analysis of grain size distribution (Appendix Table C-2, Figure 3-2). 
1995 Summer Monitoring 

50% 

- Lot 1 sediments (NW Bay sediment) 

40% 1 NWBay 

30% -+ inltial Lot 1 sediment 

20% 

10% 

0% 

50% 

- Lot 2 sediments (NW Bay sediment and added slit) jock 1 

NW Bay 

Outside 

50% 

- Lot 3 sediments (local or Outside @ NW Bay W 

! 

40% - Outside @ NW Bay W Arm 

Outside @ Outside 

30% 

20% 

10% 

0% 

125 mrn 6.3 mrn 2 mm 1 mm 500 p 250p 125 p 63 p silflclay 

Grain Size 

Figure 3-2. Grain size distribution for test sediments used in the littleneck clam 

recruitment experiment, 1994-95. 
1995 Summer Monitoring 

Additional sediment was composited from the remaining sediments in each treatment for 

analysis of TOC and TKN (Appendix Table C-2). At Block Island, samples were taken 

from each pot for PAH analysis to test the possible influence of a gradient of residual 

hydrocarbons across this site. 

Statistical Analysis 

Various statistical analyses were applied to quantitatively describe the abundance data 

and to evaluate the significance of the findings. Randomization tests were run to determine 

significant lot or site effects (ANOVA) and differences between lots or sites (t-tests). Only ' 

two-tailed t-test results were considered. The randomization routines were adapted from 

algorithms published by Edgington (1987). 

RESULTS 

Littleneck Clam Transplant Experiment 

Recoverv /Survival 

The 1994-95 littleneck clam transplant experiment recovery rates are depicted 

graphically in Figure 3-1. Recovery of marked clams at both sites was 70 percent (Table 

3-1; Appendix Table C-3). At Outside Bay two of the three wooden quadrats (Lots 2 and 

7) were disturbed by a tidal stream, yet recovery averaged 64 percent (57 and 71 percent). 

At Block Island recovery ranged from a low of 15 percent (Lot 6) to 96 percent (Lot 3; 

Figure 3-3). Very low recoveries from Lots 6 and 5 are believed to be artifacts of physical 

disturbances of the experimental sites, since both are well below the rates of survival and 

recovery of clams in the same area in the 1991 and 1992 transplant experiments. 

Mussel bed cleaning activities were carried out on the beach immediately above the clam 

transplant experiment location at Block Island in August 1994. Boat and foot traffic 

associated with this effort may have compromised the results of this experiment. If it is 

assumed that Lots 5 and 6 were physically disturbed, the mean survival of transplanted 

clams from the two remaining quadrats on the left side of the experiment (Lots 3 and 8) was 

higher (92.6 percent) than the survival in the two lots at the more heavily oiled right side of 

the transect (Lots 4 and 9,81.1 percent survival). When PAH data are available, a 

relationship between clam survival and PAH in these four quadrats will be investigated. 
1995 Summer Monitoring 

Table 3-1. Summary of littleneck clam marWrecovery experiment at Outside Bay and 

Block Island sites. 

# Recovered % Live clams 

Source Planted location # Planted Live Dead recovered 

Lot 1 Block Island Outside Bay 80 69 3 86% 

Lot 2 Block Island Outside Bay 82 4 5 2 55% 

All Block Island clams 162 114 5 70% 

Lot 3 Outside Bay Block Island 

Lot 4 Outside Bay Block Island 

Lot 5 Outside Bay Block Island 

Lot 6 Outside Bay Block Island 

Lot 7 Outside Bay Outside Bay 

Lot 8 Outside Bay Block Island 

Lot 9 Outside Bay Block Island 

All Outside Bay clams 

Overall 769 525 13 68% 

There were 18 marked and recovered clams from all lots excluded from the age 

analysis: 12 dead clams were recovered; of these, 7 showed little or no growth following 

planting, 2 were broken and could not be aged, and the remaining 3 showed some 

growth. Three live clams were broken in recovery and could not be aged. Data from 

three clams were suspect and not used in the growth analysis. Of the clams used in the 

growth analysis, 61 (11 percent) appeared to have had no growth in the year following 

transplanting. 

Age and Growth Analysis 

Growth data from the clam transplant experiment are provided in Appendix Table 

C-3. Three age classes of clams (ages 5,6, and 7) had a sufficient number of clams to 

allow comparisons among experimental treatments (Figure 3-4). Significant differences 

were found between clam lots (lot effect) for all three age classes in an ANOVA. For age 

6 and 7 clams at Outside Bay, the local clams, marked and replanted at this location, 

showed significantly greater growth than did Block Island clams transplanted to the site. 

Overall, Outside Bay clams of ages 5 and 6 showed significantly greater growth, 

regardless of location, than did Block Island clams. 
1995 Summer Monitoring 

QQQ $92 
1995 Summer Monitoring 

Significant differences in average growth were found between lots of Outside Bay 

clams transplanted to Block Island. The highest average growth for all age 5 and 6 clams 

recovered at Block Island was found in Lot 3 clams planted at the left-center of the 

experimental transect in a portion of the site that in past years has shown a low residual 

sediment PAH (Figure 3-4). For age 7 clams, greatest growth was seen in Lot 6 at the. far 

left end of the transect in the area of lowest residual PAH (Figure 3-4). 

Recruitment Experimenf 

Sediment Ouality 

Samples of the defaunated test sediments from Northwest Bay (Lot 1) and the test 

mixture of Northwest Bay sediment and fine organic mud (Northwest Bay with added 

silt fraction: Lot 2) were analyzed for grain size, TOC, and TKN (Table 3-2; Figure 3-2). 

The Northwest Bay sediment was coarse grained with 6.25 percent fines (5 125 p). The 

test sediment also had lower TOC (0.5 percent) and TKN (49.5 parts per million [ppm]) 

than the other sediments used in the experiment. The test mixture of Northwest Bay 

sediment with added silt was finer grained (20 percent fines) than the straight Northwest 

Bay sediment, but still had a low TOC value (0.67 percent). The TKN value .was 

substantially higher at 399 ppm. Block Island sediments from the lower intertidal 

infauna station had 16.5 percent fines, 2.1 percent TOC, and 513 ppm TKN. Outside Bay 

sediments from the lower intertidal infauna station had 12.3 percent fines, 1.8 percent 

TOC, and 224 ppm TKN. 

Experimental pots filled with Northwest Bay sediments (Lot 1) and placed at Block 

Island and Outside Bay had accumulated increased proportions of fines (Figure 3-2) and 

increased TKN in June 1995, by the end of the experiment (Table 3-2). Percentage fines 

and TOC were essentially unchanged, and TKN increased only slightly in pots returned 

to Northwest Bay. This confirms that there are few sources of fines or organic matter in 

the sediment or water column at this site. The Northwest Bay sediments with added silt 

also showed an increase in fines over the experiment at Block Island and Outside Bay, 

but no change at Northwest Bay. TOC was considerably higher in pots from this lot 

when recovered in 1995 and TKN increased over the exposure period at Northwest Bay 

and Outside Bay, but not at Block Island. Block Island and Outside Bay sediments placed 

in pots at the various locations generally showed increases in percentages of fines and in 

TKN over the experiment and decreases in TOC (Table 3-2). 
1995 Summer Monitoring 
1995 Summer Monitoring 

Littleneck Clam Recruitment 

Recruitment of age 0 and 1 littleneck clams in the pots between 1994 and 1995 was 

variable and inconsistent. No recruitment occurred in any test lot at the Northwest Bay 

West Arm site (Table 3-2). If the Outside Bay results are examined, the experiment 

would appear to have worked as expected: low recruitment (0.2 clams/pot) occurred in 

the raw Northwest Bay sediments; addition of silt to those sediments was associated 

with increased recruitment (1.4 clams/pot); and highest recruitment (2.2 clams/pot) 

occurred in local Outside Bay sediments (Table 3-2). Results from the Block Island 

experiment contradict this pattern, however. The lowest recruitment was in the 

Northwest Bay sediments with added silt (these pots had a mean of 47.6 percent fines), 

and highest recruitment was in unaltered Northwest Bay sediment (1.8 clams/pot; 14.2 

percent fines). The local Block Island sediments had intermediate recruitment (1.0 

clams/pot). 

Recruitment of littlenecks to these experimental units (pots) did not appear to be 

related to the nature of sediments placed in the pots in 1994. The higher recruitment at 

the Block Island and Outside Bay locations and very poor recruitment at Northwest Bay 

West Arm is consistent with results from infaunal core sampling in previous years 

(Figure 3-5). Rates of recruitment per unit area in the pot sampling were lower at all 

stations than in infaunal cores collected at the same lower elevation stations in other 

years. This may be the result of the disturbance caused by the warm-water treatment 

used to kill indigenous organisms at the start of the experiment or to some effect of the 

pots and stake on the recruitment behavior of the veligers as they settled from the 

plankton. 

Presence of several larger littleneck clams in pots of local sediments at Block Island 

and Outside Bay indicates that the warm-water treatment was insufficient to kill all the 

indigenous clams before the sediments were placed in the pots. Presence of three larger 

clams in Northwest Bay plus silt pots at Block Island indicates that some clams may 

have entered the pots from the surface. Possibly mussel bed cleaning activities 

immediately up slope from the experiment in the late summer of 1994 dislodged clams 

that were able to rebury in the pots. No larger clams were found in raw Northwest Bay 

sediments at Block Island (or elsewhere), however. 
1995 Summer Monitoring 

Table 3-2. Recruitment of age 0 and 1 littleneck clams to experimental pots with % fines ($125 

p), TKN, and TOC 

Test sediments 

Lot 1 Lot 2 Lot 3 

Block Island NWB NWB + silt sediments Local sediments 

Mean abundance of P. 

staminea (age 0 and 1) 

% Fines 

TKN (PP~) 

TOC (%) 

NW Bay W. Arm 

Mean abundance of P. 

staminea (age 0 and 1) 

% Fines 

TKN (PP~) 

TOC (%) 

Outside Bay 

Mean abundance of P. 

staminea (age 0 and 1) 

% Fines 

TKN (PP~) 

TOC (%) 

Initial sediments 

% Fines 

sediments 

1.8 

14.2% 

'31 0 

0.7% 

NWB 

sediments 

0 

5.8% 

110 

0.4% 

NWB 

sediments 

0.2 

15.8% 

270 

0.7% 

NWB 

sediments 

6.3% 

49.5 

0.5% 

NWB + silt sediments 

NWB + silt sediments 

NWB + silt sediments 

Outside Bay 

sediments 

0 

Local sediments 

Local sediments 

Block Island 

Outside Bay 

12.3% 

224 

TOC 6) ' 1.8% 

Infaunal Recruitment 

Mean abundance of macroinfaunal animals in the experimental pots recovered at Block 

Island was lowest of the three sites with 42 per pot (all treatments combined); infauna in 

the Block Island pots was dominated by polychaetes, bivalves, and crustaceans (Table 3-3). 

Outside Bay was next lowest of the three sites at 46 per pot, infauna colonizing was 

dominated by gastropods, bivalves, and polychaetes. Pots at Outside Bay containing 

Northwest Bay sediments had more nemerteans than any other sediment treatment at 

Outside Bay or Block Island. 
1995 Summer Monitoring 

Northwest Bay West Arm had the highest overall density of infaunal organisms at a 

mean of 83 per pot (all treatments combined). This abundance, which was statistically 

greater than that at Block Island, was driven by the overwhelming dominance of nemerteans 

in the two lots with higher percentages of fines (Northwest Bay sediments with silt added 

and Outside Bay). In previous sampling at Northwest Bay, numbers of nemerteans have 

never been particularly high; apparently those nemerteans present invaded the pots and 

favored the high content of fines in two of the lots. Northwest Bay local sediments, which 

had a lower percentage of fines, had a more diverse infauna with gastropods, nemerteans, 

crustaceans, and polychaetes all abundant. 
1993 1994 1995* 

Year 

2 Figure 3-5. Mean abundance (NoJO.009 m core) of age 0 and 1 Protothaca staminea from 

summer cruises, 1990-95. * Value is mean of all sediment lots for a site. 
1995 Summer Monitoring 

Table 3-3. Mean abundance (no./ 0.009 m2 core) of macroinfaunal animals in experimental pots 

recovered in July 1995. 

NWB local (Lot 1) NW Bay + silt (Lot 2) Outside Bay (Lot 3) 

Taxon Mean SD Count Mean SD Count Mean SD Count 

NW Bay W. Arm 

Anthozoan 0.00 0.00 5 0.40 0.55 5 0.00 0.00 4 

Hydrozoan 0.40 0.89 5 0.00 0.00 5 0.00 0.00 4 

Nernertea 11.20 17.37 5 72.40 55.37 5 102.25 43.92 4 

Bivalve (inc. Protothaca) 2.00 2.00 5 3.00 3.24 5 2.00 2.45 4 

Protothaca staminea 0.00 0.00 5 0.20 0.45 5 0.00 0.00 4 

Gastropoda 20.80 30.20 5 1.20 2.17 5 1.75 3.50 4 

Polyplacophora 0.00 0.00 5 0.00 0.00 5 0.00 0.00 4 

Crustacea 9.80 19.70 5 . 1.80 1.10 5 2.00 1.41 4 

Polychaete 9.80 13.74 5 2.80 1.92 5 5.25 2.75 4 

Echinoderrnata 0.00 0.00 5 0.20 0.45 5 0.00 0.00 4 

Total abundance 54.00 39.70 81.80 56.71 113.25 43.97 

NWB sediment (Lot 1) NW Bay + silt (Lot 2) Block Island local (Lot 3) 

Taxon Mean SD Count Mean SD Count Mean SD Count 

Block Island 

Anthozoan 0.00 0.00 5 0.00 0.00 5 0.00 0.00 5 

Hydrozoan 0.00 0.00 5 0.00 0.00 5 0.00 0.00 5 

Nernertea 1.20 2.17 5 0.60 0.89 5 4.60 4.04 5 

Bivalve (inc. Protothaca) 14.00 4.12 5 10.60 9.07 5 14.60 2.61 5 

Protothaca starninea 1.80 1.30 5 1.20 0.84 5 4.80 2.59 5 

Gastropoda 1.80 1.64 5 2.20 2.77 5 2.00 2.35 5 

Polyplacophora 0.00 0.00 5 0.00 0.00 5 0.20 0.45 5 

Crustacea 11.80 12.48 5 9.80 8.47 5 5.00 4.00 5 

Polychaete 9.40 4.51 5 15.40 6.43 5 14.20 4.15 5 

Echinoderrnata 3.20 2.05 5 1.60 1.82 5 2.40 4.28 5 

Total abundance 41.40 11.87 40.20 20.83 43.00 6.78 

NWB sediment (Lot 1) NW Bay + silt (Lot 2) Outside Bay local (Lot 3) 

Taxon Mean SD Count Mean SD Count Mean SD Count 

Outside Bay 

Anthozoan 0.00 0.00 5 0.00 0.00 5 0.00 0.00 5 

Hydrozoan 0.00 0.00 5 0.00 0.00 5 0.00 0.00 5 

Nernertea 12.80 12.56 5 0.60 0.89 5 2.60 2.30 5 

Bivalve (inc. Protothaca) 4.60 0.55 5 14.00 6.89 5 9.40 10.67 5 

Protothaca starninea 0.20 0.45 5 1.40 1.52 5 2.40 1.67 5 

Gastropoda 48.00 102.35 5 3.40 2.61 5 12.80 17.58 5 

Polyplacophora 0.00 0.00 5 0.00 0.00 5 0.00 0.00 5 

Crustacea 1.60 2.07 5 2.80 5.72 5 1.00 0.71 5 

Polychaete 8.20 8.38 5 5.40 2.70 5 9.20 7.79 5 

Echinoderrnata 1.20 2.17 5 0.00 0.00 5 0.20 0.45 5 

Total abundance 76.40 112.59 26.20 10.87 35.20 20.43 
1995 Summer Monitoring 
CHAPTER 4 

GENERAL DISCUSSION, SUMMARY, AND 

CONCLUSIONS 

The general discussion, summary, and conclusions in this chapter are based on analyses 

conducted to date on samples collected from 1989 through 1995. It is anticipated that more 

detailed analyses of these data will be conducted and reported as funding permits. 

OVERALL IMPLICATIONS OF THE FINDINGS 

Multiple null hypotheses relating to effects of hydrocarbon contamination from the tank 

vessel Exxon Valdez and to effects of subsequent shoreline treatments have been tested in 

the seven years of this study (1989 to 1995). Many of these null hypotheses have been 

rejected; these rejections indicate that significant differences existed in the condition of 

shorelines among our three categories of sites. For the majority of the variables tested, 

especially later in the study, conditions did not differ significantly among Category 1 

(moiled) and Category 2 (oiled, but not high-pressure hot-water treated) sites. At Category 

3 sites (those that were high-pressure hot-water washed), some variables differed 

significantly from levels at other site categories, especially early in the study, and were not 

fully recovered in 1995. In other cases, patterns apparent in the field or in the data were not 

statistically significant, but the data have been included and discussed to provide 

information on the direction of qualitative relationships among the categories. Time-series 

plots including data from 1989 through 1995 are useful in evaluating these relationships. 

Plots presented in earlier reports have been updated with new data and have been modified 

somewhat to exclude data from stations not consistently sampled over the study period. 

Expectations for the qualitative relationships among the treatment categories vary with 

the nature of the variable. Opportunistic species of epibiota, for instance, would be 

expected to be more abundant at Category 3 or Category 2 sites in the early years following 

the spill. This greater abundance was even more evident in 1991 and 1992 than in 1990; 

high abundances of opportunistic barnacles, littorines (L. scufulata), and algae (Gloiopelfis 

and several encrusting forms) were observed at Category 3 middle rocky stations. For most 

of these taxa, the "bloom" of opportunistic epibiotal species seen in 1990 through 1992 had 

disappeared or was no longer as evident after 1993. Of the infauna on mixed-soft beaches, 

relatively high abundances of nematodes and oligochaetes in Category 3 beaches seen 
1995 Summer Monitoring 

through 1992 had disappeared or was no longer as evident after 1993. Of the infauna on 

mixed-soft beaches, relatively high abundances of nematodes and oligochaetes in Category 3 

beaches through 1994 and in Category 2 beaches (especially in 1992) may also represent 

opportunism. These two meiofaunal taxa ranked one and four in abundance among all 

infaunal taxa at Category 2 stations in 1992 but have declined in rklative importance since. 

The long-lived epibiotal community dominants, such as mussels, drills, limpets, and 

rockweed, known to have suffered heavy losses due to oiling and cleanup, would be 

expected to be less abundant at Category 2 and 3 sites immediately following the spill. This 

expectation was realized to a greater degree in 1990 than in 1991; by mid-summer 1991 

recovery of many of these dominants had progressed to a greater degree on Category 2 sites 

than on Category 3 sites. By 1992 recolonization by some of these dominants, most notably 

limpets (Figure 2-7) and rockweed (Figure 2-4), had more than restored abundances at 

Category 3 sites; other taxa, such as drills (Figure 2-10) and foliose red algae (Figure 2-13), 

remained depressed through 1995. 

Reduced biological controls (grazing, predation, competition) or altered habitat 

conditions may have caused some species to become more abundant for a time in the postevent assemblage. Reduced grazer populations and perhaps reduced competition for space 

allowed rockweed at the oiled middle rocky stations (Categories 2 and 3; Figure 2-4) to 

achieve coverage greater than at the reference stations; this difference persisted into 1993 

after which rockweed cover began to decline. 

This increase and decline of rockweed, in turn, influenced recovery of other associated 

species and may be responsible for the slow recovery of red algae at middle and lower rocky 

stations (Figure 2-13). Total numbers of primary grazers (littorines and Lottiidae; Figures 2- 

6 and 2-7) are no longer depressed at oiled middle rocky stations, although densities of L. 

sitkana were lower at oiled sites than at reference sites in 1995. Category differences in 

density of one of the primary predators in the intertidal zone, Nucella lamellosa, had all but 

disappeared in 1992-93. This difference reappeared in 1994 as populations at Category 1 

middle rocky stations increased in apparent response to increases in mussel and barnacle 

populations. Nucella numbers at all categories declined in 1995 in synchrony with a decline 

in mussel cover, probably due to Nucella predation during 1994. Our expectation is that, 

over time, the natural balance among predators and prey will become reestablished at 

Category 2 and 3 sites and that patterns and geographic scale of oscillations will continue 

to dampen to within the range of natural variability at unaffected sites. 
1995 Summer Monitoring 

The responses of organisms may be expected to vary between Category 3 and Category 

2 sites where differences remain in physical or chemical habitat characteristics that resulted 

from treatment. For example, recolonization by infauna could be expected to proceed 

differently on a beach with high residual oil in the sediments from that on a beach where 

washing had removed some oil, along with fines and organic matter. In some cases, 

information was not available to develop preconceptions on the expected relationships. 

Thus, the information on the qualitative patterns must be interpreted separately for each 

taxon, site category, or variate examined. In cases where the existing data knd knowledge 

do not permit explanation, continued monitoring may clarify the significance (if any) of 

these patterns. 

The statistical testing performed on the 1990 data provided a strong basis to argue that 

conditions spanning a broad spectrum of biological properties reflected the influence of 

hydrocarbon contamination on one hand and shoreline treatment on the other; however, the 

effects of the treatment predominated (Houghton et al. 1991a). Similar testing completed 

on the 1991,1992, and 1993 data provided progressively fewer instances of significant 

differences between the site categories. Differences between moiled (Category 1) and oiled 

but untreated (Category 2) stations have been insigruhcant since 1991 in most cases. 

However, several significant differences remain between biological conditions (both infauna 

and epibiota) at either of those two station categories and conditions at high-pressure hotwater washed (Category 3) stations. These results-plus trends seen over time in key 

species abundance, directions of movement seen in principal components and multivariate 

analyses, and observations during field cruises-provided strong evidence that recovery 

was underway, even at the most severely affected sites. 

The 1994 data showed as many (epibiota at middle rocky stations) or more (infauna) 

significant category effects in abundance or assemblage measures as did the 1993 data. At 

the least, this suggests that the pace of recovery had slowed considerably. In some cases 

(epibiota), continuing differences in 1995 clearly reflect continuing oscillations in disturbed 

populations and in the balance of predator-prey relationships. In other cases (infaunathrough 1994 only), continuing differences may reflect real differences in the habitat 

conditions at stations within the respective categories. We have some concerns that the 

Category 3 lower mixed-soft stations have a greater wave exposure than do Category 1 and 

2 stations and that this may, in part at least, explain the slow apparent rate of recovery of 

infauna at these sites. 
1995 Summer Monitoring 

EPlBlOTAL ASSEMBLAGES 

Analysis of two data sets from shoreline treatment effects studies conducted in 1989 for 

Exxon showed that major components of the intertidal flora and fauna inhabiting Prince 

William Sound survived at least three to four months on heavily oiled beaches (Lees et al. 

1993). Except for a few taxa, these organisms were generally present in abundances 

comparable to those at moiled beaches in the sound. Based on these 1989 studies, the 

short-term effects of the use of high-pressure hot-water on intertidal flora and fauna of the 

sound were significant: all dominant taxa except one (barnacles) suffered from 60 to 100 

percent mortality from treatments of less than three hours' duration. 

In the first year of this study (1990; 15 to 17 months following the spill), the effects of 

1989 shoreline treatments on intertidal biota remained evident and statistically significant 

at Category 3 rocky sites; flora and fauna on Category 2 beaches more closely resembled 

those on Category 1 beaches. The majority of the community dominants were present on 

Category 2 beaches in abundances similar to those on Category 1 beaches, but reduced 

numbers of some species (e.g., rockweed, L. sitknna, Nucella) at middle elevation stations 

indicated continued effects from oiling alone (see Figures 2-4,2-6, aktd 2-7). 

In 1990, statistically sigdicant differences (lower abundances) were seen in several of 

the dominant taxa of epibiota on rocky and mixed-soft (gravel/sand with some cobbles) 

beaches. Rockweed and limpets (Figures 2-4 and 2-7), both community dominants, most 

commonly exhibited lower abundances on Category 3 beaches (cf. Category 1 beaches) at 

middle and upper intertidal elevations. Other species showing significantly lower 

abundances at these beaches included littorine snails (Figure 2-6), drills (Fi,aure 2-10), and 

barnacles (Figure 2-9). At lower intertidal levels, effects of hot-water washing were not 

consistently evident in the epibiota in 1990. Filamentous green algae seem to have been 

more abundant at Category 2 and 3 stations than at controls; several taxa of red algae 

showed the opposite pattern at the single Category 3 lower station sampled (Table 2-4). 

By July 1991 substantial recovery had occurred at Category 2 and 3 sites, although 

significant differences still remained (e.g., in limpet and rockweed abundances at middle 

rocky stations) between moiled reference sites and Category 3 sites. Colonization of 

Category 3 sites by opportunistic species had been substantial, and community composition 

differed noticeably from that at Category 1 and 2 sites. 
1995 Summer Monitoring 

By 1992 the majority of the high-pressure hot-water washed beaches appeared, 

superficially at least, to have recovered. This appearance was due to the proliferation of 

rockweed at middle rocky stations on Category 2 and 3 beaches, where cover exceeded that 

on Category 1 beaches (Figure 2-4). This increased cover of rockweed was likely the result 

of reduced numbers of grazers at Category 2 sites in 1989 and' 1990 and at Category 3 sites 

from 1989 through 1991. By 1992 limpet densities had recovered at oiled middle rocky 

stations (Figure 2-7), and more normal biological controls were expected to become 

reestablished in future years. Abundances of some other important species remained 

altered at Category 3 middle rocky stations from the expected condition as represented by 

Category 1 middle stations. Hermit crabs, Littorina sitkana, Balanus glandula, Semibalanus 

cariosus, and some red algae were all more abundant in 1992 at Category 1 sites; L. scutulata, 

Gloiopeltis, S. balanoides, and encrusting brown algae were all more abundant at Category 3 

sites. This pattern suggested that an earlier stage of ecological succession was still extant at 

Category 3 middle rocky stations in 1992. 

By mid-summer 1993 overall trends indicated continued progress toward recovery with 

no significant differences in abundant or dominant taxa among categories. Cover of 

rockweed continued to increase from 1992 levels at Category 2 and 3 middle rocky stations 

to well above the average cover at Category 1 stations (Figure 2-4). This suggested that the 

ecological imbalances created by loss of grazers to oiling and treatment continued to affect 

this assemblage. The Category 3 Block Island and Northwest Bay West Arm middle 

stations continued to be heavily dominated by rockweed (> 65 percent cover; Figure 2-12), 

whereas the Northwest Bay Islet middle station remained largely devoid of rockweed and 

associated biota over about half the sampling transect. Thus, it was expected that the mean 

rockweed cover at this station would continue to increase as recolonization progressed from 

its 1993 level (32 percent) towards its pretreatment cover of 79.6 percent. In fact, the 

limited additional growth of rockweed at the barren shoreward half of this transect in 1994 

was offset by reduced cover on the seaward half so that the 1994 cover remained 

unchanged (30 percent). 

Beginning in 1994 and continuing into 1995, there was a reduction in cover of rockweed 

at middle elevation stations sampled on oiled rocky habitats; in contrast, cover at moiled 

reference sites increased somewhat in 1994 and declined by a like amount in 1995. The 

reduction at oiled sites appeared to be the result of the natural culmination of the life cycle 

of this species; post-spill and post-treatment colonization by germlings in late 1989 and 

early 1990 developed to reproductive maturity in 1992 over broad areas of the central 

sound. Depressed numbers of littorines and limpets (Figures 2-6 and 2-7) allowed this 
1995 Summer Monitoring 

development to proceed with minimal grazing pressure. By 1993 this cohort of rockweed 

was showing signs of senescence, and numbers of grazers had increased to the point where 

the decline seen in 1994 was inevitable. By 1995, rockweed cover at Category 3 sites was 

lower than it had been since 1990 following treatment. 

In 1994 littorine densities at oiled middle rocky stations (Figure 2-6) converged with 

those at unoiled middle stations, a sign of increasing stability. In 1995 numbers of L. sifkana 

increased at unoiled stations to a density about three timesthat at both categories of oiled . 

middle stations. Limpet densities increased at oiled middle stations in 1994 (Figure 2-7), 

probably in response to the abundance of weakened rockweed plants. In 1995 limpet 

numbers continued to rise at Category 3 middle stations despite the decline in rockweed. 

Future trends in populations of these grazers are expected to depend on the extent and 

pattern of the die-back and recolonization of rockweed that occurs in the next few years. 

A second predator/prey association at rocky middle intertidal stations, that of the drill 

(Nucella spp.) and its prey (barnacles and mussels), appears to be subject to more dynamic 

natural fluctuations in Prince William Sound than does the grazer/rockweed association 

discussed above. In contrast to the relative stability of rockweed cover (Figure 2-4) and 

littorine/limpet densities (Figures 2-6 and 2-7) at Category 1 stations over the years, 

abundances of mussels, barnacles, and drills have varied much more dramatically. A dense 

set of mussels that occurred at all middle stations, but especially at Category 1 stations in 

1991, has provided prey for expansion of drill populations at these sites for the 1992 

through 1994 period (Figure 2-8). A strong set of the opportunistic barnacle S. balanoides at 

Category 1 sites in 1994 supplemented this prey base and led to a sharp increase in drill 

abundance in 1994 (Figure 2-9). Heavy predation losses resulted in a decline in both prey 

species, as well as in the predator in 1995. These changes at unoiled reference sites were 

greater in magnitude than fluctuations in this predator prey system at oiled sites. 

As defined by Ganning et al. (1984) and endorsed by this study (Houghton et al. 

1993a), recovery will be considered to be complete when variability of measured population 

and assemblage parameters at oiled sites is consistently within the range of natural 

fluctuations at unoiled sites. Despite the apparent bloom (1991-93) and decline (1994-95) 

of rockweed at oiled stations, the trend toward normal (e.g., Category 1) abundance levels 

for grazers and predators at middle elevation rocky stations suggest that biologcal controls 

will become increasingly influential. Because of the wide natural fluctuations in the 

drill/mussel-barnacle association, it may be that these components of the intertidal 

assemblage can be considered to be recovered at middle rocky stations. At least through 
1995 Summer Monitoring 

1995, the fluctuations in the grazer/rockweed association appear to be greater at the oiled 

middle stations than at reference stations thus, this component of the intertidal assemblage 

does not appear to have recovered. Again, we expect a gradual damping of oscillations in 

abundances of dominant species at affected sites over the coming years. 

At the single lower elevation rocky station sampled 1990 through 1995, examination of 

pretreatment (May 1989) data provides significant insight into the effects of treatment. 

Washing conducted at this station had no noticeable immediate effect on cover of rockweed 

(15.4 percent cover in May before treatment, 22.8 percent cover in June after treatment 

[Houghton et al. 19951); this apparent lack of effect suggested that temperatures used may 

have been lower or that wash durations were reduced (by shorter emersion time) from those 

experienced at the middle elevation station where rockweed was totally removed (Figure 2- 

4). Impacts of washing on a group of long-lived red algae were severe, however. Cover 

dropped from more than 70 percent to less than 20 percent immediately following the 

washing (Houghton et al. 1995). During the next four years, cover of rockweed expanded to 

over 65 percent in 1993 before declining to about 50 percent in 1994 and increasing to 57.1 

percent in 1995. Nonencrusting red algae have not exceeded 20 percent cover since 1989, 

and recovery to pre-treatment abundance appears unlikely for several more years. 

Reestablishment of red algae at middle elevations is proceeding more rapidly as evidenced 

at the paired Northwest Bay West Arm middle rocky stations (Figure 2-13). 

Large fluctuations in abundances of limpets and littorine snails at the lower Northwest 

Bay Islet station have generally been brief; densities of littorines appear to be trending 

toward the more normal (very low) numbers of these species seen at Category 1 and 2 lower 

stations (Table 2-4). Density of limpets remains high, however, with a strong recruitment of 

small limpets in 1995 (Table 2-4). 

Substantial recovery of most variables characterizing intertidal epibiotal assemblages 

was apparent in mid-summer 1994. Few differences remained between moiled rocky 

stations and stations that were oiled but not treated with high-pressure hot-water washes. 

Recovery at high-pressure hot-water washed rocky stations, however, continues to lag 

behind that at oiled but untreated stations both in terms of reduced abundance of some 

taxa and increased abundance of others. 

The clearance of the middle and upper intertidal biota from rocky habitats during hotwater washing was relatively thorough and consistent over scales of 10s or 100s of meters 

of shoreline. Thus, recolonization by rockweed occurred in synchrony over these spatial 
1995 Summer Monitoring 

scales resulting in the monoculture of same-aged rockweed plants so evident in 1990 and 

1991. The natural scale of patchiness of rockweed ages has been altered because large areas 

of shoreline have rockweed all the same age. In a natural middle intertidal community, 

different cohorts of rockweed exist in patches that exist on the scale of decimeters or, at 

most, meters. Typically, several cohorts from germlings to senescencing plants are 

represented in any given 0.25-m2 quadrat. 

In the natural community, senescence of any particular cohort does not greatly alter the 

overall rockweed cover nor does it greatly impact the several species dependent on the 

rockweed for food, shelter, or protection from desiccation. The significance of resetting of 

the intertidal successional clock to zero with the hot-water treatment of large areas of rocky 

intertidal is becoming more clear as this study progresses. 

INFAUNAL EXPERIMENTS 

Littleneck Clam Transplants 

The 1994 to 1995 transplanting experiment was confounded by apparent disturbances 

at both the Block Island and Outside Bay sites. At Block Island, work crews engaged in 

mussel bed cleaning may have disturbed at least two of the six quadrats containing 

transplanted Outside Bay clams. A tidal stream meandered across the three quadrats at 

Outside Bay and removed two of the wooden frames. The four remaining quadrats at Block 

Island had survival percentages ranging from 80 to 96 percent with highest survival on 

portions of the beach that have historically had lower residual PAH levels. Survival and 

recovery of clams from these quadrats were generally higher than from four quadrats of 

clams from Bainbridge Bight transplanted to the same area for four months in 1991. In 1991 

survival ranged from 62 percent at the most contaminated side of the beach to 88 percent at 

the cleanest end. This may indicate that residual hydrocarbons continue to exert a negative 

influence on survival of transplanted clams but that the toxicity is declining. 

Similar conclusions can be drawn from measurements of growth of transplanted clams 

at Block Island: growth was greater for clams at quadrats in portions of the site historically 

shown to have lower residual PAH levels; similar results were seen in the 1991 transplant 

experiment. 

Recruitment Experiment 

The recruitment experiment provided information on what may be one of the strongest 

factors controlling littleneck clam recruitment, i.e., there was no recruitment of littlenecks to 
1995 Summer Monitoring 

any of the pot treatments at Northwest Bay West Arm strongly suggests one or both of two 

possible conclusions: 

1. There are few planktonic clams encountering the beach at the head of the West Arm 

at the time of metamorphosis to the benthic form, and/or 

2. The size of the experimental plots was insufficient to be detected by veligers in the 

process of settling from the plankton. 

Presumably, the higher silt content in two of the treatments would have been found more 

favorable for settling from the plankton had there been larvae present in the water column 

and had the increased silt been detected. It seems more probable that there are few larvae 

in the waters that reach the site; there are likely no significant areas of clam populations 

remaining in Northwest Bay as all possible clam beaches (e.g., adjacent to the site on the 

Rocky Islet) suffered the same hydraulic washing as did the West Arm study site. This, in 

conjunction with our conclusions from the 1991 transplant experiment (very high survival of 

clak transplanted to the site), suggests that transplanting of littlenecks into the West Arm 

would be a viable means of accelerating recovery of clam populations at this beach. 

Results of the recruitment experiment were inconclusive with respect to the influence of 

sediment grain size, TOC, and TKN on clam recruitment. At one of the sites (Outside Bay), 

highest recruitment was in pots with the greatest percentage of fines; at the other site (Block 

Island), highest recruitment was in pots with the coarsest sediment (from Northwest Bay 

West Arm without silt addition). The higher recruitment at the Block Island andoutside 

Bay locations and very poor recruitment at Northwest Bay West Arm is consistent with 

results from infaunal core sampling in previous years (Figure 3-5). Rates of recruitment area 

in the pot sampling were lower at all stations than in infaunal cores collected at the same 

lower elevation stations in other years. This may be the result of the disturbance caused by 

the warm-water treatment used to kill indigenous organisms at the start of the experiment or 

to some effect of the pots and stake on the recruitment behavior of the veligers as they 

settled from the plankton. 

Presence of several larger littleneck clams in pots of local sediments at Block Island and 

Outside Bay suggests that the warm-water treatment was insufficient to kill all the 

indigenous clams before the sediments were placed in the pots. Presence of three larger 

clams in Northwest Bay plus silt pots (known to lack clams at the beginning of the 

experiment) at Block Island indicates that some clams may have entered the pots from the 

surface. Possibly mussel bed cleaning activities immediately up slope from the experiment 
1995 Summer Monitoring 

in the late summer of 1994 dislodged clams that were able to rebury in the pots. No larger 

clams were found in raw Northwest Bay sediments at Block Island (or elsewhere), however. 

It seems that the basic design of this experiment was sound and well directed to the 

question at hand (Is reduced level of fines responsible for the poor recruitment of littleneck 

clams at Northwest Bay?). However, three factors should be altered, if the experiment is to 

be repeated: 

1. The experimental units should be larger to increase the chance of detection by 

veligers and to reduce the chance that wave action will alter the surficial sediments 

to match those of the surrounding beach. 

2. The experimental sediments should be closely examined for the presence of living 

organisms; heat/freshwater treatment should be increased to ensure that no live 

clams are planted with the experimental sediments., 

3. The experimental units should be inspected during the experiment to ensure that 

disturbances do not occur to bias the results; ideally, the experimental units should 

be placed in the spring before settlement of veligers is expected and retrieved in the 

fall after settlement is complete to avoid the winter period of high wave action. 
CHAPTER 5 

REFERENCES AND ACRONYMS 

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Doubleday, Garden City, New Jersey. 

Brooks, K. M. 1994. Histopathological examination of archived bivalves Mytilus edulis 

trossulus and Prototheca staminea (sic) in support of the Prince William Sound long-term 

monitoring. Prepared by Aquatic Environmental Sciences, Port Townsend, Washington for 

NOAA, Seattle. 

Eberhardt, L. L., and J. M. Thomas. 1991. Designing environmental field studies. Ecological 

Monographs 61 (1):53-73. 

Edgington, E.'S. 1987. Randomization Tests. 2nd Ed. New York: Marcel Dekker. 341 pp. 

Gabrielson, P. W., R. F. Scagel, and T. B. Widdowson. 1989. Keys to the Benthic Marine 

Algae and Seagrasses of British Columbia, Southeast Alaska, Washington, and Oregon. 

Vancouver, BC, Canada: University of British Columbia. 187 pp. 

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Boston: Butterworth Publishers. pp 7-35 

Harrison, 0. R. 1991. An overview of the Exxon Valdez oil spill: Proceedings, 1991 

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Houghton, J. P. 1973. Intertidal ecology of Kiket Island, Washington, with emphasis on age 

and growth of Protothaca starninea and Saxidomus giganteus (Lamellibranchia: Veneridae). 

Seattle: College of Fisheries, University of Washington. 178 pp. 

Houghton, J. P., D. C. Lees, H. Teas, H. Cumberland, S. Landino, and W. B. Driskell. 

1991a. Evaluation of the condition of intertidal and shallow subtidal biota in Prince William 

Sound following the Exxon Valdez oil spill and subsequent shoreline treatment. Volume II. 

NOAA NOS ORCA Technical Memorandum 67. Seattle: Hazardous Materials Response 

and Assessment Division, NOAA. 201 pp. 

Houghton, J. P., D. C. Lees, W. B. Driskell, and A. J. Mearns. 1991b. Impacts of the Exxon 

Valdez spill and subsequent cleanup on intertidal biota-1 year later. Proceedings 1991 

International Oil Spill Conference: Prevention,' Behavior, Control, and Cleanup. March 47, 

1991, San Diego, California. Washington, D.C.: American Petroleum Institute. 

pp 467-475 

Houghton, J. P., A. K. Fukuyama, D. C. Lees, H. Teas, III, H. L. Cumberland, P. M. Harper, 

T. A. Ebert, and W. B. Driskell. 1993a. Evaluation of the 1991 condition of Prince William 

Sound shorelines following the Exxon Valdez oil spill and subsequent treatment: Volume II, 

1991 biological monitoring survey. NOAA Technical Memorandum NOS ORCA 67. 

Seattle: Hazardous Materials Response and Assessment Division, NOAA. 201 pp. 
1995 Summer Monitoring 

Houghton, J. P., A. K. Fukuyama, D. C. Lees, P. J. Hague, H. L. Cumberland, P. M. Harper, 

and W. B. Driskell. 1993b. Evaluation of the 1992 condition of Prince William Sound 

shorelines following the Exxon Valdez oil spill and subsequent shoreline treatment: Volume 

II, 1992 biological monitoring survey. NOAA Technical Memorandum NOS ORCA 73. 

Seattle: Hazardous Materials Response and Assessment Division, NOAA. 201 pp. , 

Houghton, J. P., R. H. Gilmour, D. C. Lees, S. C. Lindstrom, and W. B. Driskell. 1994. 

Evaluation of the 1993 condition of Prince William Sound littoral biota following the Exxon 

Valdez oil spill and subsequent shoreline treatment. Seattle: Pentec Environmental, Inc. 

Houghton, J. P., R. H. Gilmour, D. C. Lees, W. B. Driskell, and S. C. Lindstrom. 1995. 

Long-term recovery (1989-1994) of Prince William Sound littoral biota following the Exxon 

Valdez oil spill and subsequent shoreline treatment. Seattle: Final report of Pentec 

Environmental, Inc., to Hazardous Materials Branch, NOAA. 

Jahns, H. O., J. R. Bragg, L. C. Dash, and E. H. Owens. 1991. Natural cleaning of shorelines 

following the Exxon Valdez spill. Proceedings 1991 International Oil Spill Conference: 

Prevention, Behavior, Control, Cleanup, March 47,1991, San Diego, California, Washington, 

D.C.: American Petroleum Institute. pp 167-176. 

Kozloff, E. N. 1987. Marine Invertebrates of the Pacific Northwest. Seattle: University of 

Washington Press. 511 pp. 

Lees, D. C., W. B. Driskell, and J. P. Houghton. 1993. Effects of shoreline treatment 

methods on intertidal biota in Prince William Sound.1993 International Oil Spill Conference: 

Prevention, Preparedness, Response. March 29 to April 1,1993, Tampa, Florida. Washington, 

D.C.: American Petroleum Institute. pp. 345-354. 

Lethcoe, J. and N. Lethcoe. 1989. Cruising Guide to Prince William Sound. Valdez, Alaska: 

Prince William Sound Books. 154 pp. 

Michel, J. and M. 0. Hayes. 1991. Geomorphology controls on the persistence of shoreline 

contamination from the Exxon Valdez oil spill. Seattle: Hazardous Materials Response 

Branch, NOAA. 307 pp. 

Michel, J., M. 0. Hayes, W. J. Sexton, J. C. Gibeaut, and C. Henry. 1991. Trends in natural 

removal of the Exxon Valdez oil spill in Prince William Sound from September 1989 to May 

1990. Proceedings 1991 International Oil-Spill Conference: Prevention, Behavior, Control, 

Cleanup, March 47,1991, San Diego, California, Washington, D.C.: American Petroleum 

Institute. pp 181-187. 

Page, D. S., E. S. Gilfillan, P. D. Boehm, and E. J. Harner. 1993. Shoreline ecology program 

for Prince William Sound, Alaska, following the Exxon Valdez oil spill: Part 1-Study 

design and methods. A Compilation of Papers Presented at the Third Symposium on 

Environmental Toxicology and Risk Assessment: Aquatic, Plant, and Terrestrial, 

April 25-28, 1993, Atlanta, Georgia. 

Zeh, J. E., J. P. Houghton, and D. C. Lees. 1981. Evaluation of existing marine intertidal 

and shallow subtidal biological data. Prepared by Mathematical Sciences Northwest, Inc., 

and Dames & Moore. Prepared for MESA Puget Sound Project, Office of Environmental 

Engineering and Technology, Office of Research and Development, US EPA. EPA 

Interagency Agreement No. D6-E693-EN. Seattle: Dames & Moore. 262 pp. 
1995 Summer Monitoring 

ANOVA 

un 

GPS 

lD 

lan 

mm 

MLLW 

NOAA 

PAH 

PPm 

PPt 

SD 

SE 

TKN 

TOC 

ACRONYMS 

analysis of variance 

centimeter 

Global Positioning System 

identification 

kilometer 

meter 

millimeter 

mean lower low water 

National Oceanic and Atmospheric Administration 

polycyclic aromatic hydrocarbons 

parts per million 

parts per thousand 

standard deviation 

standard error 

total Kieldahl nitrogen 

total organic compound 
1995 Summer Monitoring 
APPENDIX A 
Table A-1 Location, site, station, habitat type, and total height of all sampling 1989-95. 

Tidal ht. Epibiota Inf. core Mega-inf. Sediment Mytilus Proto. 

Location and site Habitat Station ( ft ) 114 m2 1 mm 114 m2 tPAH tissue tissue 

Category l--Unoiled 

Bass Harbor (NA-27) 

Rocky Rock 

Boulderlcobble Boulderlcobble 

Outside Bay (NA-26) 

Soft 1 

Soft 2. 

Eshamy Bay (EB-7) 

Rocky 

Sheep Bay 

Soft 

Gravellcobble 

Gravellcobble 

Gravelfsand 

Gravellsand 

Rock 

Rock 

Rock 

Rock 

Rock 

Rock 

Gravelfsand 

Bainbridge Bight 

Soft Gravellsand 

Crab Bay (EV-500) 

Rocky Rock 

Rock 

Soft Gravelfcobble 

Gravellcobble 

Gravellcobble 

UP 

UP 

Mid 

Low 

UP 

Mid 

Low 

Mid 

UP 

Mid 

Low 

UP 

Mid 

Low 

UP 

Mid 

Low 

Low 

Mid 

Low 

UP 

Mid 

Low 

8.83 4ABCDFHJ 

7.65 ADF 

5.37 ABD 

1.23 ABD 

9.45 ABDF 

4.90 ABDF 

0.33 ABDF 

9.72 ABDF 

4.55 ABDF 

2.27 ABDF 

6.90 134ABCDFGHJ 

0.68 13ABDFGH 

9.51 ABDF 

5.49 ABDF 

2.63 ABF 

D 

DF 

ABD 

ABD 

ABDF 

14ABDF ABDF 

13ABCDFGHJ ADFH ABCDFGJ 

D 

ABDF 

ABDF 

BF 

BDF 

ABDF 

ABDF 

4ABDF ABDF 

3ABDFGH ADFH ABDFG 

CDEFGH DFH CDFG 

BDF 

BDF 

BDF 

ABDF ABDF 

ABFGHJ AFH ABFGJ 

FH 

ABD 

BGHJ 

DGH 

ABDF 

D 

ABDFHG 

FH 

ABD 

ABDFGH 

DFGH 

DFGH CFGH 

ABDFGHJ 

ABDFGHJ 

DFGH 

Seward Boulderlcobble Mid D 

? 

C-L 

l=C~ise 1,April 1989; 2=Cruise 2, May 1989; 3=Cruise 3, July 1989; 4=Cruise 4, Seplernber 1989; A=July 1990; B=Septernber 1990; C=May 1991; D=July 1991; E=Seplernber 1991; F=July 1

1995. 
fp 

Table A-1 (continued) 

N 

Tidal ht. Epibiota Inf. core Mega-inf. Sediment Mytilus Proto. 

Location and site Habitat Station (ft) 114 m2 1 mm 114 m2 tPAH tissue tissue 

Category 2-Oiled, untreated 

Northwest Bay 

West Arm Rock Rock 

Rock 

Herring Bay (KN-5000) 

Rocky Rock 

Rock 

Soft Gravellcobble 

Gravellsand 

Bay of Isles (KN-07) 

Rocky Rock 

Soft Gravellcobble 

Gravellcobble 

Snug Harbor (KN-401) 

Rocky Rock 

Rock 

Rock 

Soft Gravellcobble 

Gravellsand 

Gravellsand 

Block Island (EL-1 I) 

Soft Graveusand 

Mussel Beach South 

Soft Gravellsand 

Gravellsand 

Crafton Island (CR-5) 

Soft Gravellcobble 

Gravellcobble 

Mid 

Low 

UP 

Mid 

UP 

Low 

Mid 

UP 

Low 

UP 

Mid 

Low 

UP 

Mid 

Low 

Low 

Mid 

Low 

UP 

Mid 

9.64 4ABCDFGHJ DGH 

5.37 1234ABCDFGHJ BDFH ABDFGH 

7.21 ABDF BDFH 

0.23 ABCDF 1234ABCDFGHJ ABDFH BDFG DFGH FGH D

4.80 134ABD 

ABD 

-0.14 BD 

ABDH ABDFH 

ABDH 

BD 

8.41 4ABCDFGHJ ABDFG 

5.13 234ABCDFGHJ ABDFGJ ABDFGHJ 

1.52 23ABDFGH ABDF 

9.28 ABDF ABDF 

5.74 ABCDF ABDF ADF ADFHJ 

-0.15 ABCDF 234ABCDFGHJ ADFH ABDFGJ G DFGH D

3.59 ABDF ABCDFGHJ ' ADFH BCDFGHJ FGJ CDFGH D

4.40 ABDF BDF ABDF ABDFJ 

-0.89 ACDF 234ADFGHJ ADFH ADFG GH FGH D

8.52 ABD 

5.01 ABD D 

ABDF 

ABDF ABDFHJ 

Gravellcobble Low 2.95 ABD ABDG ABD ABDFGH G G 

Outside Bay (NA-26) 

Rocky Rock UP 8.96 4ABCDFGHJ ABF 

l=C~ise 1, April 1989; 2=Crulse 2, May 1989; 3=Cruise 3, July 1989; 4=Cruise 4, September 1989; A=July 1990; B=September 1990; C=May 1991; D=July 1991; E=September 1991; F=July 199

1995. 
Table A-1 (continued) 

Tidal ht. Epibiota Inf. core Mega-inf. Sediment Mytilus Proto. 

Location and site Habitat Station ( ft ) 114 m2 1 mm 114 m2 tPAH tissue tissue 

Rock Mid 5.27 134ABCDFGHJ F 

Rock 

Ingot Island (IN-24) 

Boulder/cobble RocWboulder 

Soft Gravellcobble 

Category 3-Oiled, treated 

Point Helen (KN-405) Site 1 

Boulderlcobble Boulderlcobble 

Boulderlcobble 

Boulder/cobble 

Point Helen (KN-405) Site 3 

Boulderlcobble Boulderlcobble 

Boulderlcobble 

Boulderlcobble 

Northwest Bay 

Rocky Islet (EL-55) Rock 

Rock 

Rock 

West Arm Rock Rock 

Rock 

W. Arm Soft (EL-54 Gravellcobble 

GraveVsand 

Shelter Bay (EV-21) 

Soft Gravellsand 

Gravellsand 

Low 

Mid 

Low 

UP 

Mid 

Low 

UP 

Mid 

Low 

UP 

Mid 

Low 

Mid 

Low 

Mid 

Low 

UP 

Mid 

0.70 I 3ABCDFGH BDF 

6.80 BD BDF BDFH 

2.33 BDF BDFG BDF BDFG G DG 

7.25 ADF 

4.16 ABD 

-1.46 ABD 

F 

ABDFH ABDFH 

BDFH 

ADFGH 

ABDFGJ ABDFGHJ 

ABDFG 

6.20 ABDFH BDF ABDFJ ABDFHJ 

0.63 ABDFH 23ABCDFGHJ ADFW ABCDFGJ G DFGH 

8.57 BDF 

6.1 8 ABDF 4ABDF 

DF 

ABDF ABDFGHJ 

Gravellsand Low 1.02 ABDF 234ABCDFGHJ ADFH ABCDFGJ DFGH 

Sleepy Bay (LA-18) 

Soft Gravellcobble UP 3.56 ADF AB ABDF 

Gravelhand Mid 1.48 ABDF ABDF ABDF ABDFGHJ , 

? Graveband Low -0.85 BDF DFGHJ DFH DFGJ DF 

0, 

l=Cruise 1, April 1989; 2=Cmise 2, May 1989; 3=Cruise 3, July 1989; 4=Cruise 4, September 1989; A=July 1990; B=September 1990; C=May 1991; D=July 1991; E=September 1991; F=July 1

1995. 
? Table A-1 (continued) I@ 

Tidal ht. Epibiota Inf. core Mega-inf. Sediment Mytilus Proto. G

Location and site Habitat Station ( ft ) 114 m2 I mm 114 m2 tPAH tissue tissue 

Ne Latouche Cobble (LA-15) 

Boulderlcobble Boulderlcobble Mid 3.19 ABDF ABDF ABDFH 

Boulder/cobble Low 0.71 BDF BF 

Smith lsland (SM-06) 

Boulderlcobble Boulderlcobble UP 8.35 BD . N-4 Boulderlcobble Mid 6.35 ABD 

Boulderlcobble Low 2.14 ABD 

Mussel Beach South (EL-13) 

Rocky Rock UP 4ABCDFGHJ 

Mussel Beach North (EL-13) 

Rocky Rock UP 

Rock Mid 

Rock Mid (ABC) 

Rock Low 

Omni Site 

Boulder/cobble RocWboulder Mid 

FGH 

FGH 

F 

FGH 

BDH 

ABDH ABDGH 

ABDH 

Block lsland (EL-11) 

Rocky Rock UP 8.27 CDFGHJ 

Rock Mid 3.82 ABCDFGHJ A ABDFGHJ 

Soft Gravellsand UP ABD BF A ABDFH BGH 

Gravellsand Mid 6.49 ADF 

Elrington lsland West 

Rocky Rock UP F 

Rock Mid 4FH F F 

Rock Low FH F 

Soft Gravellsand Mid F 

Gravellsand Low FGH FH FG GH FGH 

Elrington lsland East 

Rocky Rock UP F F 

Rock Mid 4FH F 

Rock Low FH 

Soft Graveusand Mid F F 

Gravellsand Low . F 

Elrington Islet-East UP FH 

l=Cruise 1, April 1989; 2=Cruise 2, May 1989; 3=Cruise 3, July 1989; 4=Cruise 4, September 1989; A=July 1990; B=September 1990; C=May 1991; D=July 1991; E=September 1991; F=July 1992

1995. 
Table A-1 (continued) 

Tidal ht. Epibiota Inf. core Mega-inf. Sediment Mytilus Proto. G

Location and site Habitat Station ( ft ) 114 m2 1 mm 114 m2 tPAH tissue tissue 

Elrington Islet-West UP FH 

Elrington Islet--North UP FH 

Bainbridge Bight Low D 

Soft 

l=Cruise 1, April 1989; 2=Cruise 2, May 1989; 3=Cruise 3, July 1989; 4=Cruise 4, September 1989; A=July 1990: B=Seplernber 1990; &May 1991; DJuly 1991; E=Septernber 1991; F=July 199

1995. 
1995 Summer Monitoring 

Table A-2 Water temperature PC) and salinity (ppt) at sampling sites in Prince William Sound, 

July 1995. 

Site Habitat Depth Date Temp. Salinity 

Block Island 

Block Island 

Crab Bay 

Crab Bay 

Eshamy Bay 

Eshamy Bay 

Rock 0.3 m 711 2/95 11.2 28.2 

Rock 2.4 m 711 2/95 10.3 29.0 

Rock 0.3 m 711 5/95 11 .O 27.7 

Rock 1.8 m 711 5/95 10.8 ' 27.8 

Rock 0.3 m 711 4/95 13.0 22.9 

Rock 1.8 m 711 4/95 12.8 23.8 

Northwest Bay Islet Rock 0.3 m 711 3/95 10.1 29.0 

Northwest Bay Islet Rock 1.8 m 711 3/95 10.4 29.2 

Outside Bay 

Outside Bay 

Snug Harbor 

Snug Harbor 

Softl 

Softl 

Rock 

Rock 
APPENDIX B 
Table B-1 Rocky middle intertidal epibiota, July 1995 

Bass Harbor Block 

Taxon Mean SD SE Count Mean SD 

Biidingia minima 0.30 0.45 0.20 5 0.00 0.00 

Blue-green algae, spheroids 0.60 0.42 0.19 5 0.00 0.00 

Bryophyta, unid. 0.00 0.00 0.00 5 0.00 0.00 

Ciadophora sericea 0.00 0.00 0.00 5 0.1 0 0.22 

Coraliina sp. 0.00 0.00 0.00 5 0.00 0.00 

Elachista fucicola 0.20 0.27 0.12 5 0.00 0.00 

Endocladia muricata 0.10 0.22 0.10 5 0.00 0.00 

Endozoic green algae 0.40 0.22 0.10 5 0.10 0.22 

Fucus gardneri 4.40 6.23 2.79 5 10.70 12.32 

Fucus gardneri (germlings) 1.60 2.04 0.91 5 1 .50 1 .OO 

Gloiopeltis furcata 1.40 1.64 0.73 5 0.20 0.27 

Haiosaccion glandiforme 0.10 0.22 0.10 5 0.00 0.00 

Hildenbrandia rubra 0.50 0.50 0.22 5 3.00 3.08 

Leathesia difformis 0.10 0.22 0.1 0 5 0.00 0.00 

Melanosiphon intestinalis 0.10 0.22 0.10 5 0.20 0.45 

Neorhodomela oregona 0.40 0.89 0.40 5 1.20 2.68 

Porphyra spp. 0.10 0.22 0.10 5 0.00 0.00 

Raifsia fungiformis 0.00 0.00 0.00 5 0.10 0.22 

Ralfsia spp. 0.00 0.00 0.00 5 1.20 2.68 

Verrucaria spp. 0.00 0.00 0.00 5 9.80 14.94 

Balanus glandula (Oh) 6.00 10.67 4.77 5 0.80 0.76 

Baianus/Semibalanus spp. ("4 0.00 0.00 0.00 5 1.20 2.14 

Balanus/Semibalanus spp., set (%) 0.00 0.00 0.00 5 0.60 0.82 

Chthamalus dalli (% set) 0.50 0.00 0.00 5 0.30 0.45 

Chthamalus dalii ("7) 3.50 2.24 1 .OO 5 0.30 0.27 

Littorina spp., eggs ("A) 0.00 0.00 0.00 5 0.50 0.87 

Mytilus cf. trossulus (% spat) 0.80 1.25 0.56 5 0.10 0.22 

Mytiius cf. trossulus ("A) 0.00 0.00 0.00 5 0.40 0.89 

Semibalanus balanoides ("A set) 7.40 5.13 2.29 5 0.00 0.00 

Semibalanus balanoides (%) 50.80 15.59 6.97 5 0.10 0.22 

Semibalanus cariosus ("A) 0.60 1.34 0.60 5 0.00 0.00 

?' 
?' Table B-1 (continued) 

Bass Harbor Block 

Taxon Mean SD SE Count Mean SD 

Acarina 

Clinocottus acuticeps 

Llgia sp. 

Littorina scutulata 

Llttorina scutulata Ouv.) 

Littorina sitkana 

Littorina sitkana Ouv.) 

Lottia digitalis 

Lotfia pelta 

Lotliidae, unid. 

Lotliidae, mid. (juv.) 

Nucella lamellosa 

Nucella lima 

Pagurus hirsutiusculus 

Protothaca staminea 

Tectura persona 

Tectura scutum 

Balanus glandula (04 dead) 

Balanus/Semibalanus spp. (% dead) 

Chthamalus dalli (% dead) 

Myt1lu.i cf. trossulus (dead) 

Semibalanus balanoides (% dead) 

Semibalanus balanoides (% set, dead) 

BouiderKobble (%) 

Gravel/Sand(%) 

Oil cover (%) (primary) 

Oil scale (primary) 

Oil Scale (secondary) 

Rock (%) 

Water (%) 0.20 0.45 0.20 5 4.20 8.84 
Table B-1 (continued) 

Eshamy Bay Herring Bay 

Taxon Mean SD SE Count Mean SD SE. 

Blidingia minima 

Blue-green algae, spheroids 

Bryophyta, unld. 

Cladophora sericea 

Corallina sp. 

Elachista fucicola 

Endocladia muricata 

Endozolc green algae 

Fucus gardneri 

Fucus gardneri (germlings) 

Gloiopeltis furcata 

Halosaccion glandiforme 

Hildenbrandla mbra 

Leathesla difformis 

Melanosiphon intestinalis 

Neorhodomela oregona 

Porphyra spp. 

Ralfsla fungiformis 

Ralfsia spp. 

Verrucaria spp. 

Balanus glandula (%) 

Balanus/Semibalanus spp. (%) 

Balanus/Semibalanus spp., set (Oh) 

Chthamalus dalli (% set) 

Chthamalus dalll (%) 

Littorina spp., eggs (Oh) 

Mytilus cf. trossulus (Oh spat) 

Mytilus cf. trossulus (Oh) 

Semibalanus balanoides (% set) 

Semibalanus balanoides (Oh) 

Semlbalanus cariosus (%) 0.00 0.00 0.00 5 0.00 0.00 0.00 
w Table B-1 (continued) 

Eshamy Bay Herring ~a

Taxon Mean SD SE Count Mean SD SE. 

Acarina 

Clinocottus acuticeps 

Ligia sp. 

Littorina scutulata 

Littorina scutulata (juv.) 

Littorina sitkana 

Littorina sitkana (juv.) 

Lottia digitalis 

Lottia pelta 

Lottiidae, unld. 

Lottiidae, unld. (juv.) 

Nucella lamellosa 

Nucella lima 

Pagurus hlrsutiusculus 

Protothaca staminea 

Tectura persona 

Tectura scutum 

Balanus glandula (Oh dead) 

Balanus/Semlbalanus spp. (% dead) 

Chthamalus dalli (% dead) 

Mytilus cf. trossulus (dead) 

Semlbalanus balanoldes (% dead) 

Semibalanus balanoides (Oh set, dead) 

Boulder/Cobble (%) 19.00 42.49 19.00 5. 0.00 0.00 0.00 

Gravel/Sand(%) 1 .OO 2.24 1 .OO 5 0.00 0.00 0.00 

011 cover (%) (primary) 0.00 0.00 0.00 5 0.70 0.76 0.34 

Oil scale (prlmary) 0.00 0.00 0.00 5 4.80 2.68 1.20 

011 Scale (secondary) 0.00 0.00 0.00 5 0.00 0.00 0.00 

Rock (%) 80.00 44.72 20.00 5 100.00 0.00 0.00 

Water (%) 0.30 0.45 0.20 5 0.00 0.00 0.00 
Table B-1 (continued) 

Mussel Beach South NW Bay Rocky Inlet 

Taxon SD SE. Count Mean SD SE. 

Blidingia minima 0.00 0.00 5 0.00 0.00 0.00 

Blue-green algae, spheroids 0.00 0.00 5 0.00 0.00 0.00 

Bryophyta, unid. 0.22 0.10 5 0.00 , 0.00 0.00 

Cladophora sericea 0.00 0.00 5 0.00 0.00 0.00 

Corallina sp. 0.00 0.00 5 0.00 0.00 0.00 

Elachlsta fucicola 0.00 0.00 5 0.00 0.00 0.00 

Endocladia muricata 0.00 0.00 5 0.00 0.00 0.00 

Endozolc green algae 0.22 0.10 5 0.00 0.00 0.00 

Fucus gardneri 3.13 1.40 5 0.1 0 0.22 0.10 

Fucus gardneri (germlings) 0.22 0.10 5 0.20 0.27 0.12 

Gloiopeltis furcata 0.22 0.10 5 0.00 0.00 0.00 

Halosaccion glandiforme 0.00 0.00 5 0.00 0.00 0.00 

Hildenbrandia rubra 0.27 0.12 5 0.30 0.27 0.12 

Leathesia difformis 0.00 0.00 5 0.00 0.00 0.00 

Melanosiphon Intestinalis 0.00 0.00 5 0.00 0.00 0.00 

Neorhodomela oregona 0.00 0.00 5 0.00 0.00 0.00 

Porphyra spp. 0.00 0.00 5 0.00 0.00 0.00 

Ralfsia fungiformis 0.00 0.00 5 0.00 0.00 0.00 

Ralfsia spp. 0.00 0.00 5 0.80 1.79 0.80 

Verrucaria spp. 5.32 2.38 5 0.20 0.45 0.20 

Balanus glandula (Oh) 0.45 0.20 5 0.20 0.45 0.20 

Balanus/Semibalanus spp. (Oh) 0.00 0.00 5 0.00 0.00 0.00 

Balanus/Semibalanus spp., set (%) 0.00 0.00 5 0.1 0 0.22 0.1 0 

0.00 0.00 5 0.1 0 0.22 0.10 

Chthamalus dalll (Oh set) 

Chthamalus dalli (Oh) 0.42 0.19 5 0.30 0.45 0.20 

Littorina spp., eggs (Oh) 0.00 0.00 5 0.00 0.00 0.00 

Mytilus cf. trossulus (% spat) 0.22 0.10 5 0.00 0.00 0.00 

Mytilus cf. trossulus (Oh) 0.00 0.00 5 0.00 0.00 0.00 

Semibalanus balanoides (Oh set) 0.00 0.00 5 0.10 0.22 0.10 

Semibalanus balanoides ("A) 0.00 0.00 5 0.20 0.27 0.12 

Semlbalanus cariosus (%) 0.00 0.00 5 0.00 0.00 0.00 

?I 
x Table B-1 (continued) 

Mussel Beach South NW Bay Rocky Inlet 

Taxon SD SE. Count Mean SD SE. 

Acarina 

Clinocottus acuticeps 

Ligia sp. 

Littorina scutulata 

Littorina scutulata Uuv.) 

Littorina sltkana 

Littorina sitkana Uuv.) 

Lottia digitalis 

Lottia pelta 

Lottiidae, unid. 

Lottiidae, unid. Uuv.) 

Nucella lamellosa 

Nucella lima 

Pagurus hirsutiusculus 

Protothaca staminea 

Tectura persona 

Tectura scutum 

Balanus glandula (% dead) 

Balanus/Semibalanus spp. (% dead) 

Chthamalus dalli (% dead) 

Mytilus cf. trossulus (dead) 

Semibalanus balanoldes (?A dead) 

Semlbalanus balanoides (Oh set, dead) 

BoulderICobble (%) 

Gravel/Sand(%) 

Oil cover (%) (primary) 

Oil scale (primary) 

Oil Scale (secondary) 

Rock (%) 

Water (%) 0.00 0.00 5 0.00 0.00 0.00 
Table B-1 (continued) 

- - 

Taxon 

- - - 

Outside Bay Snug Harb

SD SE. Count Mean SD S

Blidingia minima 

Blue-green algae, spheroids 

Bryophyta, unid. 

Cladophora sericea 

Corallina sp. 

Elachista fucicola 

Endocladia muricata 

Endozoic green algae 

Fucus gardneri 

Fucus gardneri (germlings) 

Gloiopeltis furcata 

Halosaccion glandiforme 

Hildenbrandia rubra 

Leathesia difformis 

Melanosiphon intestinalis 

Neorhodomela oregona 

Porphyra spp. 

Ralfsla fungiformis 

Ralfsia spp. 

Verrucaria spp. 

Balanus glandula (05%) 

Balanus/Semibalanus spp. (Oh) 

Balanus/Semibalanus spp., set (07) 

Chthamalus dalli (Oh set) 

Chthamalus dalli (%) 

Littorina spp., eggs ("3) 

Mytiius cf. trossulus (Oh spat) 

Mytilus cf. trossulus (%) 

Semibalanus balanoides (% set) 

Semibalanus balanoides (Oh) 

Semibalanus cariosus (%) 0.00 0.00 5 0.00 0.00 0.
1995 Summer Monitoring 

Om~OrOOOrOOOOOOO OOOONO 000000 

.9'?,9c\l9N9'?9999999 999979 999999 OObO~OOOOOOOOOOO 000000 000000 
1995 Summer Monitoring 
w 

o Table B-2. (continued). 

Block Island Crab Bay 

Taxon Mean S.D. S.E. Count Mean S.D. 

Balanus glandula (% set) 0.35 0.63 0.20 10 0.1 0 0.32 

Balanus glandula (07) 3.60 4.50 1.42 10 2.45 4.49 

Balanus rostratus (%) 0.00 0.00 0.00 10 0.00 0.00 

Balanus/Semibalanus spp., set (07) 0.00 0.00 0.00 10 0.00 0.00 

Chthamalus dalli (07 set) 0.15 0.24 0.08 10 0.1 0 0.21 

Chthamalus dalli (%) 0.50 0.24 0.07 10 0.95 1.82 

Encrusting bryozoan (%) 0.00 0.00 0.00 10 0.00 0.00 

Lntorina spp., eggs (07) 0.25 0.26 0.08 10 0.00 0.00 

Mytilus cf. trossulus (% spat) 0.90 0.66 0.21 10 0.55 0.28 

Mytilus cf. trossulus (%) 8.65 8.92 2.82 10 6.55 7.41 

Nucella spp. (% eggs) 0.00 0.00 0.00 10 0.00 0.00 

Semibalanus balanoides (% set) 3.15 1.94 0.61 10 0.40 0.32 

Semibalanus balanoides (%) 4.85 4.89 1.55 10 0.95 1.04 

Semibalanus cariosus (% set) 0.00 0.00 0.00 10 0.05 0.16 

Semibalanus cariosus (%) 0.00 0.00 0.00 10 0.05 0.16 

Siphonaria thersites, eggs &) 0.00 0.00 0.00 10 0.25 0.26 

Spirorbidae, unid. (%) 0.00 0.00 0.00 10 0.00 0.00 
1995 Summer Monitoring 

000 00000mbm0Nco~000000000-000 ~o~,00000~bmOmvm00000wOOo0)wOv 

ooo odooo~i~dGddooooowdoodoo~ 
46 

C-l 

h, Table B-2. (continued). 

Block Island Crab Ba

Taxon Mean S.D. S.E. Count Mean S.D. 

Balanus crenatus (% dead) 0.05 0.16 0.05 10 0.00 0.00 

10 0.30 

Balanus glandula (% dead) 0.25 0.26 0.08 0.35 

Balanus/Semibalanus spp. (% dead) 0.05 0.16 0.05 10 0.00 0.00 

Balanus/Semibalanus spp. (% set, dead) 0.00 0.00 0.00 10 0.00 0.00 

Chthamalus dalli ('A dead) 0.15 0.24 0.08 10 0.00 0.00 

Encrusting bryozoan (% dead) 0.00 0.00 0.00 10 0.00 0.00 

Mytilus cf. trossulus (dead) 4.20 3.61 1.14 10 2.70 3.74 

Semibatanus balanoides (% dead) 0.25 0.26 0.08 10 0.75 1.18 

Semibalanus balanoides (% set, dead) 0.00 0.00 0.00 10 0.00 0.00 

Semibalanus cariosus (% set, dead) 0.00 0.00 0.00 10 0.00 0.00 

Boulder/Cobble (%) 0.1 0 0.32 0.10 10 30.80 36.68 

Gravel/Sand(%) 0.20 0.42 0.13 10 14.70 26.89 

Mud (%) 0.00 0.00 0.00 10 0.00 0.00 

Rock (%) 99.70 0.48 0.15 10 54.50 47.93 

Water (%) 3.95 6.73 2.13 10 0.10 0.21 
1995 Summer Monitoring 
F 

Table 8-2. (continued). 

Eshamy Bay Herring 

Taxon Mean S.D. S.E. Count Mean S.D. 

Balanus glandula (% set) 0.00 0.00 0.00 10 0.00 0.00 

Balanus glandula (%) 0.75 1.62 0.51 10 0.15 0.24' 

Balanus rostratus (%) 0.05 0.1 6 0.05 10 0.00 0.00 

Balanus/Semibalanus spp., set (Oh) 0.00 0.00 0.00 10 0.00 0.00 

Chtharnalus dalli (% set) 0.15 0.24 0.08 10 0.00 0.00 

Chtharnalus dalli (07) 0.95 1.14 0.36 10 0.35 0.34 

Encrusting bryozoan (%) 0.00 0.00 0.00 10 0.00 0.00 

Lifiorina spp., eggs (%) 0.00 0.00 0.00 10 0.00 0.00 

Mytilus cf. trossulus (% spat) 0.20 0.35 0.1 1 10 0.80 0.54 

Mytilus cf. frossulus (07) 1 .OO 1.94 0.61 10 0.95 1.23 

Nucella spp. (% eggs) 0.00 0.00 0.00 10 0.00 0.00 

Semibalanus balanoides (% set) 5.25 6.53 2.06 10 16.80 5.29 

Semibalanus balanoides (07) 4.15 12.60 3.98 10 37.80 20.26 

Semibalanus cariosus (% set) 0.00 0.00 0.00 10 0.00 0.00 

Semibalanus cariosus (%) 0.10 0.21 0.07 10 0.00 0.00 

Siphonaria thersites, eggs (%) 0.00 0.00 0.00 10 0.00 0.00 

Spirorbidae, unid. (%) 0.00 0.00 0.00 10 0.00 0.00 
Table B-2. (continued). 

Eshamy Bay Herring 

Taxon Mean S.D. S.E. Count Mean S.D. 

Acarina P 7 P 

Anthopleura artemisia 

Clinocottus aculiceps 

Emplectonema gracile 

Gammaridea, unid. 

Gnorimosphaeroma oregonensis 

Heptacarpus sp. 

Lacuna spp. 

Lacuna variegata 

Leptasterias hexactis 

Littorina scutulata 

Littorina scutulata ouv.) 

Littorina sitkana 

Littorina sitkana ow.) 

Loftia peita 

Lottiidae, unid. 

Lottiidae, unid. (juv.) 

Musculus spp. 

Nucella lamellosa 

Nucella lima 

Onchidella borealis 

Pagutus granosimanus 

Pagurus hlrsuliusculus 

Pentidotea wosnesenskii 

Pododesmus macroschismata 

Polychaeta, unid. 

Searlesia dira 

Siphonaria thersites 

Tectura persona 

Tectura scufum 

Encrusting coralline algae (dead) 

Fucus gardneri (dead) 0.25 0.35 0.1 1 10 0.30 0.35 
46 

w 

cn Table B-2. (continued). 

Eshamy Bay Herrin

Taxon Mean S.D. S.E. Count Mean S.D. 

Balanus crenatus (% dead) 0.00 0.00 0.00 10 0.00 0.00 

Balanus glandula (% dead) 0.20 0.42 0.1 3 10 0.00 0.00 

Balanus/Sernibalanus spp. (% dead) 0.00 0.00 0.00 10 0.00 0.00 

Balanus/Sernibalanus spp. (% set, dead) 0.00 0.00 0.00 10 0.00 0.00 

Chthamalus dalli ("h dead) 0.1 0 0.21 0.07 10 0.00 0.00 

Encrusting bryozoan (% dead) 0.00 0.00 0.00 10 0.00 0.00 

Mytilus cf. trossulus (dead) 6.10 10.29 3.25 10 2.20 2.49 

Sernibalanus balanoides (% dead) 0.10 0.21 0.07 10 0.05 0.16 

Semibalanus balanoides (% set, dead) 0.05 0.16 0.05 10 0.00 0.00 

Sernibalanus cariosus ("9 set, dead) 0.00 0.00 0.00 10 0.00 0.00 

Boulder/Cobble (%) 64.10 41 .50 13.12 10 8.80 15.85 

Gravel/Sand(%) 2.40 2.76 0.87 10 1.80 3.82 

Mud (%) 0.00 0.00 0.00 10 0.50 1.08 

Rock (%) 27.50 44.80 14.17 10 88.90 18.40 

Water (%) 1 .50 4.74 1 .50 10 0.00 0.00 
1995 Summer Monitoring 

0 2 

a 

0 

-0 

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9) 

5 V) 'a 1 -. 

e 

2 2 3 a g % a 2- .w E 80 m E2 ~3 zm corn$ 22 8 C E sa.-zo " $ .? 

rr: m a .+so2 ,pag,, a 5z.sg2 2ss a, 0 Q*% E.~..,c g$~~ Q o 'c m m 6SB f :%Q >gaS4 .s s &s . 5 .s 3~~3 qF.52~ 

a ES~B mL., 3 gmm.z.z e ,,.mg~d;ij,~g~g-~~s e~s.-Q~ E.- -cQ.Ee ='a4 .s--.6 ~~~ro~r~crs,o,.m~$$pp'a.oc asmo0gS bEaCEe~~~S~~~

r .~l t3 .g % E-YW.~~~ Q9~m ~.~S+~~gg~~~-$$~~$g~

,,~b~~g~.- z?jNppwwQ~c SO o %ownsE 8 gp~~&$a~0SggBg~aaa-~_0~~v,~,m~~&

~QS:,ZCSPPSKCC~CCYI:'~ ~C[)QOQQQ~Q msoo CL- ~~~~~~~QQQU~~UUUUL~ZZ~~STSSZZZQQ
1995 Summer Monitoring 
Table B-2. (continued). 

Anthopleura artemisia 

Clinocottus acuticeps 

Ernplectonema gracile 

Gammaridea, unid. 

Gnorimosphaeroma oregonensis 

Heptacarpus sp. 

Lacuna spp. 

Lacuna variegata 

Leptasterias hexactis 

Littorina scutulata 

Littorina scutulata &v.) 

Littorina sitkana 

Littorina sitkana Uuv.) 

Lottia pelta 

Lottiidae, mid. 

Lottiidae, unid. (juv.) 

Musculus spp. 

Nucella lamellosa 

Nucella lima 

Onchidella borealis 

Pagurus granosimanus 

Pagums hirsutiusculus 

Pentidofea wosnesenskii 

Pododesrnus macroschisma fa 

Polychaeta, unid. 

Searlesia dira 

Siphonaria thersites 

Tectura persona 

Tectura scutum 

Encrusting coralline algae (dead) 

Fucus gardnen (dead) 0.35 0.67 0.21 10 0.20 0.26 
1995 Summer Monitoring 
1995 Summer Monitoring 
g Table B-2. (continued). 

Snug Harbor NW Bay W Arm 

Taxon Mean S.D. S.E. Count Mean S.D. 

Balanus alandula (% set) 0.00 0.00 ' 0.00 10 0.1 0 0.22 

- 

Balanus glandula (%) 1.15 0.82 0.26 10 1.80 1.25 

Balanus rostratus (Oh) 0.00 0.00 0.00 10 0.00 0.00 

Balanus/Semibalanus spp., set (Oh) 0.00 0.00 0.00 10 0.00 0.00 

Chthamalus dalli (% set) 0.40 0.21 0.07 10 0.10 0.22 

Chthamalus dalli (%) 0.45 0.28 0.09 10 9.80 1.10 

Encrusting bryozoan (%) 0.00 0.00 0.00 10 0.00 0.00 

Littorina spp., eggs (Oh) 0.00 0.00 0.00 10 0.00 0.00 

Mytilus cf. trossulus (% spat) 0.30 0.26 0.08 10 0.50 0.00 

Mytilus cf. trossulus (Oh) 2.60 2.75 0.87 10 0.00 0.00 

Nucelia spp. (% eggs) 0.05 0.16 0.05 10 0.00 0.00 

Semibalanus balanoides (% set) 9.05 9.04 2.86 10 11.40 9.71 

Semibalanus balanoides (%) 0.75 1.01 0.32 10 1.70 1.57 

Semibalanus cariosus (% set) 0.00 0.00 0.00 10 0.00 0.00 

Semibalanus cariosus (%) 0.00 0.00 0.00 10 0.20 0.27 

Siphonaria thersites, eggs (%) 0.00 0.00 0.00 10 0.10 0.22 

Spirorbidae, unid. (%) 0.00 0.00 0.00 10 0.10 0.22 
1995 Summer Monitoring 
FP Table 8-2. (continued). 

Snug Harbor NW Bay W Arm 

Taxon Mean S.D. S.E. Count Mean S.D. S

Balanus crenafus (% dead) 0.00 0.00 0.00 10 0.00 0.00 0

Balanus glandula (% dead) 0.55 0.90 0.28 10 0.20 0.27 0

Balanus/Semibalanus spp. (% dead) 0.00 0.00 0.00 10 0.00 0.00 0

Balanus/Semibalanus spp. (% set, dead) 0.25 0.35 0.11 10 0.00 0.00 0

Chthamalus dalli (% dead) 0.10 0.21 0.07 10 0.70 0.27 0

Encrusting bryozoan (% dead) 0.00 0.00 0.00 10 0.00 0.00 0

Mytilus cf. trossulus (dead) 4.1 0 4.56 1.44 10 0.00 0.00 0

Semibalanus balanoides (% dead) 0.45 0.93 0.29 10 0.50 0.00 0

Semibalanus balanoides (% set, dead) 0.00 0.00 0.00 10 0.00 0.00 0

,Semibalanus cariosus (% set, dead) 0.00 0.00 0.00 10 0.00 0.00 0

BoulderICobble (%) 90.05 7.84 2.48 10 0.00 0.00 0

Gravel/Sand(%) 9.95 7.84 2.48 10 0.00 0.00 0

Mud (%) 0.00 0.00 0.00 10 0.00 0.00 0

Rock (%) 0.00 0.00 0.00 10 100.00 0.00 0

Water (%) 0.90 2.02 0.64 10 5.30 8.36 3
Table B-2. (continued). 

NW Bav W Arm Untreated 

Taxon Mean S.D. S.E. Count 

Acrosiphonia sp. 0.00 0.00 0.00 5 

Black crust (maybe H. wbra w/ endophytic green) 

Blidingia minima 

Blue-green algae, spheroids 

Chcletornorpha torfuosa 

Cladophora sericea 

Cryptosiphonia woodil 

Dictyosiphon foenlculaceus 

Elachista fucicola 

Encrusting coralllne algae 

Encrusting green algae 

Endocladia muricata 

Endozolc green algae 

Enterornorpha intestinalis 

Enteromorpha Iinza 

Fucus gardneri 

Fucus gardneri (germlings) 

Gloiopeltis furcata 

Halosaccion glandiforme 

Hildenbrandia rubra 

Leathesia difformis 

Mastocarpus papillatus 

Mazzaella spp. (Iridaea sp.) 

Melanosiphon intestinalis 

Monostroma grevillei 

Nemalion helminthoides 

Neorhodornela oregona 

Neorhodomela larix 

Palmaria callophylloides 

Petrocelis spp. 

Pilayella littoralis 

Pterosiphonia bipinnata 

Ralfsia spp. 

Rhodochorton purpureum 

Scytosiphon lomentaria 

Soranthera ulvoidea 

Sphacelaria rigidula 

UlvaAJlvaria spp. 

Verrucaria spp. 0.00 0.00 0.00 5 
Table'B-2. (continued). 

NW Bav W Arm Untreated 

Taxon Mean S.D. S.E. Count 

Balanus glandula (Oh set) 0.30 0.45 0.20 5 

Balanus - ulandula I%) 2.30 2.28 1.02 5 . . Balanus rostratus (%) 0.00 0.00 0.00 5 

Balanus/Semibalanus spp., set (Oh) 0.00 0.00 0.00 5 

Chthamalus dalli (% set) 0.80 0.76 0.34 5 

Chthamalus dalli (Oh) 8.80 4.71 2.1 1 5 

Enc~sting bryozoan (%) 0.00 0.00 0.00 5 

Littorina spp., eggs (7%) 0.00 0.00 0.00 5 

Mylilus cf. trossulus (Oh spat) 2.10 1.75 0.78 5 

Mytilus cf. trossulus (%) 0.00 0.00 0.00 5 

Nucella spp. (% eggs) 0.00 0.00 0.00 5 

Semibalanus balanoides ("h set) 4.60 6.49 2.90 5 

Semibalanus balanoides (%,I 0.50 0.35 0.16 5 

Semibalanus cariosus (% set) 0.80 0.76 0.34 5 

Semibalanus cariosus (%) 1.40 2.04 0.91 5 

Siphonaria thersites, eggs (Oh) 0.00 0.00 0.00 5 

Spirorbidae, unid. (%) 0.00 0.00 0.00 5 
Table B-2. (continued). 

NW Bay W Arm Untreated 

Taxon Mean S.D. S.E. Count 

Acarina P 

Anthopleura artemisia 

Clinocoffus acuticeps 

Emplectonema gracile 

Gammaridea, unid. 

Gnorimosphaeroma oregonensis 

Heptacarpus sp. 

Lacuna spp. 

Lacuna varlegata 

Leptasterias hexactis 

Littorina scutulata 

Lifforina scutulata (iuv.) 

Littorina sitkana 

Littorina sitkana (iuv.) 

Lottia pelta 

Lottiidae, unid. 

Lottiidae, unid. Uuv.) 

Musculus spp. 

Nucella lamellosa 

Nucella lima 

Onchidella borealis 

Pagurus granosimanus 

Pagurus hirsutiusculus 

Pentidotea wosnesenskii 

Pododesmus macroschismata 

Polychaeta, unid. 

Searlesia dira 

Siphonaria thersites 

Tectura persona 

Tectura scutum 

Encrusting coralline algae (dead) 

Fucus gardneri (dead) 0.40 0.42 0.19 5 
1995 Summer Monitoring 
1995 Summer Monitoring 

Table B-3 Rocky lower intertidal epibiota, July 1995. 

NW Bay Rocky Inlet 

Taxon Mean SD SE Count 

Acrosiphonia sp. 

Blidingia minima 

Blue-green algae, spheroids 

Cladophora sericea 

Corallina frondescens 

Cryptosiphonia woodii 

Elachista fucicola 

Encrusting coralline algae 

Endozoic green algae 

Enteromorpha linza 

Fucus gardneri 

Fucus gardneri (germlings) 

Gloiopeltis furca ta 

Halosaccion glandiforme 

Hildenbrandia rubra 

Leathesia difformis 

Mastocarpus papillatus 

Mazzaella spp. (Iridaea sp.) 

Melanosiphon intestinalis 

Monostroma grevillei 

Neorhodomela oregona 

Palmaria mollis 

Petrocelis spp. 

Pilayella littoralis 

Polysiphonia spp. 

Pterosiphonia bipinnata 

Ptilota filicina 

Ralfsia spp. 

Scytosiphon lomen taria 

Sphacelaria rigidula 

Tokidadendron kurilensis 

Ulva/Ulvaria spp. 

Balanus glandula (5%) 

Balanus rostratus (Oh) 

Bryozoan, gray epiphytic 

Chthamalus dalli ("A set). 

Chthamalus dalli (%) 

Littorina spp., eggs ("A) 

Mytilus cf. trossulus (% spat) 

Semibalanus balanoides (% set) 

Semibalanus balanoides ("A) 

Semibalanus cariosus (% set) 

Semibalanus cariosus (03) 

Spirorbidae, unid. (%) 0.30 0.26 0.08 10 
1995 Summer Monitoring 

Table B-3 (Continued) 

Acarina 

Amphiporus spp. (Nemertea, white) 

Anthopleura elegantissima 

Clinocoftus acuticeps 

Gammaridea, unid. 

Katharina tunicata 

Lacuna spp. 

Littorina scutulata 

Littorina scutulata (juv.) 

Littorina sitkana 

Lottiidae, unid. (juv.) 

Margarites marginatus 

Musculus spp. 

Nemertea, pink 

Nemertea, unid. 

Nucella lamellosa 

Pagurus hirsutiusculus 

Pisaster ochraceus 

Pycnopodia helianthoides (juvenile) 

Searlesia dira 

Fucus gardneri (dead) 

Balanus glandula (99 dead) 

Balanus rostratus (% set, dead) 

Balanus/Semibalanus spp. (79 set, dead) 

Chthamalus dalli (% dead) 

Hiatella arctica (dead) 

Mytilus cf. trossulus (dead) 

Semibalanus balanoides (% dead) 

Semibalanus balanoides (% set, dead) 

BoulderICobble (%) 

Gravel/Sand(%) 

Mud (%) 

Rock (%) 

Water (%) 0.1 0 0.21 0.07 . - 
APPENDIX C 
Table C-1 Sediment grain size distribution, total percent fines (1 125 p), TOC, and TKN from the initial test sediments us

recruitment experiment, 1994-95. 

Test sediment 12.5 mm 6.3 mm 2 mm 1 mm 500 p 250 p 125 p 63 p Siltlclay Fines 

Outside Bay 22.3% 21.3% 11.7% 17.0% 1.6% 13.8% 3.9% 2.9% 5.5% 12.3% 

Block Island 28.1% 13.6% 26.3% 18.9% 3.9% 5.7% 1.2% 0.5% 1.8% 3.5% 

NW Bay (Lot 1) 17.7% 15.5% 35.3% 11 .l% 9.8% 4.3% 2.7% 2.4% 1.1% 6.3% 

NW Bay + added silt (Lot 2) 19.6% 11.6% 20.4% 10.1 % 6.6% 11.4% 8.7% 6.6% 5.0% 20.4% 
Table C-2 Sediment grain size distribution, total percent fines (5 p), TOC, and TKN from the sediments used in the clam recruitmen

when recovered in 1995. 

Block Island 

Lot No. Rep. 12.5 mm 6.3 mm 2 mm I mm 500p 250 p 125 p 63 p Siltlclay % Fines T

1 5 18.3% 15.5% 26.9% 11.9% 8.2% 5.5% 5.5% 4.6% 3.7% 13.7% 

Average 29.8% 18.8% 20.2% 7.4% 5.0% 4.5% 3.9% 3.1% 7.3% 14.2% 

2 5 10.7% 17.3% 26.0% 7.0% 4.3% 5.0% 3.0% 4.0% 22.7% 52.9% 

Averaue 16.9% 18.2% 23.6% 6.1% 5.1% 4.0% 3.7% 4.5% 17.9% 47.6% 

3 5 18.0% 12.3% 17.1% 8.5% 11.1% 12.3% 7.6% 3.5% 9.5% 20.6% 

Average 15.7% 13.4% 18.4% 10.0% 10.4% 11.1% 6.7% 3.3% 11.0% 21.0% 

SD 7.0% 6.0% 8.2% 4.5% 4.6% 5.0% 3.0% 1.5% 4.9% 
Table C-2 (continued) 

Northwest Bay West Arm 

Lot No. Rep. 12.5 mm 6.3 mm 2 mm 1 mm 500p 250 p 125 p 63 p siltlclay % Fines T

1 5 23.7% 17.2% 23.7% 10.1% 9.1% 9.1% 3.0% 2.0% 2.0% 7.1% 

Average 25.3% 16.0% 24.3% 11.3% 10.6% 6.6% 2.4% 1.7% 1.7% 5.8% 

2 5 19.6O/o 11.4% 15.3% 6.7% 10.2% 11.0% 6.7% 5.5% 13.7% 25.9% 

Average 23.1% 15.1% 15.0% 9.4% 8.6% 8.5% 4.0% 4.1% 12.3% 20.4% 

3 4 25.4% 18.0% 19.0% 9.2% 8.5% 7.5% 4.1% 2.7% 5.8% 12.5% 

Average 21.6% 18.3% 19.9% 8.5% 7.5% 6.3% 6.4% 3.0% 8.5% 17.9% 
Table C-2 (continued) 

Outside Bay 

Lot No. Rep. 12.5 mm 6.3 mm 2 mm I mm 500p 250 p 125 p 63 p siltlclay % Fines T

1 5 15.2% 18.3% 23.2% 16.5% 11.0% 5.5% 3.7% 2.4% 4.3% 10.4% 

Average 20.8% 15.3% 24.4% 11.0% 7.5% 5.2% 5.6% 3.6% 6.6% 15.8% 

2 5 10.3% 13.0% 19.3% 6.1% 6.4% 9.0% 6.1% 5.9% 24.0% 35.9% 

Average 14.1% 15.7% 19.4% 7.7% 5.8% 7.6% 7.4% .5.7% 16.6% 29.7% 

Average 22.6% 13.6% 18.8% 8.3% 5.3% 5.4% 7.0% 4.4% 14.7% 26.1% 

SD 10.1% 6.1% 8.4% 3.7% 2.4% 2.4% 3.1% 2.0% 6.6% 
Table C-3. Age and growth data from 1994-95 littleneck clam transplant experiment. 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1 992-93) Age 3 (1991-92) 

Total 95 94 93 9

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth. Length SD Gro

Outside Bay Lot No. 1 

4 1 23.70 21.50 2.20 16.60 4.90 10.10 6.50 4.10 6.0

5 11 26.89 2.49 25.25 3.18 1.64 21.56 3.18 3.69 16.78 2.59 4.78 10.16 3.48 6.6

6 21 28.92 2.90 26.76 2.90 2.16 23.71 2.90 3.05 20.07 2.99 3.64 14.90 2.50 5.

7 9 30.44 3.33 28.54 3.03 1.90 26.07 3.03 2.48 22.43 2.90 3.63 17.1 1 2.42 5.3

8 12 31.33 3.13 30.35 3.35 0.98 28.02 3.35 2.33 24.90 3.60 3.12 20.50 3.13 4.4

9 4 33.05 2.04 32.55 2.15 0.50 30.65 2.15 1.90 27.40 2.96 3.25 24.30 2.70 3.

10 3 34.73 1.27 33.63 2.18 1.10 32.30 2.18 1.33 29.43 2.60 2.87 25.70 2.61 3.7

11 4 32.25 0.87 31.55 1.13 0.70 30.08 1.13 1 .48 28.88 1.67 1.20 27.28 1.54 1.6

12 1 32.80 32.40 0.40 30.20 2.20 28.50 1.70 27.50 1 .O

66 

Dead 3 

86% recovery 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1 992-93) Age 3 (1991-92) 

Total 95 94 93 9

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Outside Bay Lot No. 2 

10 2 30.30 1.84 30.10 2.05 0.20 28.45 2.05 1.65 27.10 0.99 1.35 23.90 1.27 3.2

47 

Dead 2 
Table C-3. (continued) 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1 992-93) Age 3 (1 991 -92) 

Total 95 94 93 9

Age No. Length 

Block Lot No. 3 

SD Length SD Growth Length SD Growth Length SD Growth Length Gro

78 

N/C 1 1 7yr w/ initial length>end length 

96% recovery 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1992-93) Age 3 (1991-92) 

Total 95 94 93 9

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Block Lot No. 4 

65 

Dead 0 
Table C-3. (continued) 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1 992-93) Age 3 (1 991 -92) 

Total 95 94 93 9

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Block Lot No. 5 

5 6 24.58 2.21 22.68 3.14 1.90 19.88 3.14 2.80 14.85 2.28 5.03 10.17 0.98 4.6

6 8 26.45 2.06 24.41 2.91 2.04 21.54 2.91 2.88 18.40 3.49 3.14 14.09 3.36 4.3

7 9 29.58 3.85 27.91 4.84 1.67 25.09 4.84 2.82 22.02 4.14 3.07 18.09 3.58 3.

8 4 32.95 4.71 31.80 4.19 1.15 29.63 4.19 2.18 26.88 4.88 2.75 23.63 3.76 3.2

9 3 33.40 2.82 32.97 2.25 0.43 31.33 2.25 1.63 28.77 2.10 2.57 26.47 2.20 2.3

10 2 38.05 5.73 37.20 5.23 0.85 35.20 5.23 2.00 31.70 3.54 3.50 29.85 4.17 1.8

32 

Dead 3 

Last Annulus (1994-95) Age I (1993-94) Age 2 (1992-93) Age 3 (1 991 -92) 

Total 95 94 93 9

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Block Lot No. 6 

Dead 0 

15% recovery 
Table C-3. (continued) 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1 992-93) Age 3 (1 991 -92) 

95 94 93 92 Total 

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Outside Bay Lot No. 7 

Dead 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1 992-93) Age 3 (1 991 -92) 

Total 95 94 93 92 

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Block Lot No. 8 

Dead 

N/C 

1 17.30 16.00 1.30 11.80 4.20 7.20 4.60 7.2

7 21.01 3.53 18.51 1.96 2.50 15.93 1.96 2.59 10.60 2.32 5.33 5.50 1.74 5.1

9 23.84 3.61 21.33 2.81 2.51 18.23 2.81 3.10 14.87 2.81 3.37 9.57 1.82 5.3

16 25.48 3.36 23.85 3.02 1.63 21.74 3.02 2.11 18.66 2.75 3.09 14.25 2.28 4.4

20 28.47 3.34 26.82 3.38 1.65 25.13 3.38 1.70 22.51 3.37 2.62 18.23 3.17 4.2

12 31.08 3.58 29.79 3.85 1.29 28.46 3.85 1.33 25.84 3.80 2.62 22.08 3.61 3.7

11 33.35 4.27 32.15 4.10 1.19 30.65 4.10 1.51 28.65 3.98 2.00 25.56 3.15 3.0

6 32.35 3.73 30.97 3.95 1.38 29.55 3.95 1.42 27.70 3.77 1.85 25.52 3.33 2.1

82 

2 

1 1 -6 yr old w/ initial length>end length 
Table C-3. (continued) 

Last Annulus (1994-95) Age 1 (1993-94) Age 2 (1992-93) Age 3 (1 991 -92) 

Total 95 94 93 9

Age No. Length SD Length SD Growth Length SD Growth Length SD Growth Length SD Gro

Block Lot No. 9 

12 1 42.40 40.50 1 .90 38.40 2.10 35.90 2.50 34.50 1.

78 

Dead 5 

84% recovery 
1995 Summer Monitoring