National Park Service

U.S. Department of the Interior

Northeast Region

Restoration of the Turning Basin and Tidal Wetlands at 

Saugus Iron Works National Historic Site

2008 Post-Restoration Monitoring Data Report

Natural Resource Data Series NPS/NER/SAIR/NRDS—2010/054 
ON THE COVER

Restored turning basin at Saugus Iron Works NHS, September 2008. 

Photograph by: Mary-Jane James-Pirri
Restoration of the Turning Basin and Tidal Wetlands 

at Saugus Iron Works National Historic Site

2008 Post-Restoration Monitoring Data Report

Natural Resource Data Series NPS/NER/SAIR/NRDS—2010/054

Mary-Jane James-Pirri

Graduate School of Oceanography 

University of Rhode Island 

Narragansett, RI 02882 

401-874-6617 

mjjp@gso.uri.edu

John Burgess

Project Manager

CH2MHILL

25 New Chardon St. Suite 300 

Boston, MA 02117-4770 

Charles T. Roman

National Park Service

Graduate School of Oceanography 

University of Rhode Island 

Narragansett, RI 02882 

Marc Albert

National Park Service

Stewardship Program Manager Boston Harbor Islands NPA, 

Saugus Iron Works NHS, Salem Maritime NHS 

National Park Service

Boston, MA 02110 

June 2010

U.S. Department of the Interior 

National Park Service

Northeast Region 

Philadelphia, PA 
ii

The National Park Service publishes a range of reports that address natural resource topics of 

interest and applicability to a broad audience in the National Park Service and others in natural 

resource management, including scientists, conservation and environmental constituencies, and 

the public. 

The Natural Resource Data Series is intended for timely release of basic data sets and data 

summaries. Care has been taken to assure accuracy of raw data values, but a thorough analysis 

and interpretation of the data has not been completed. Consequently, the initial analyses of data 

in this report are provisional and subject to change. 

All manuscripts in the series receive the appropriate level of peer review to ensure that the 

information is scientifically credible, technically accurate, appropriately written for the intended 

audience, and designed and published in a professional manner. This report received informal 

peer review by subject-matter experts who were not directly involved in the collection, analysis, 

or reporting of the data. 

This report provides the results of a project accomplished with assistance from the NPS under 

Cooperative Agreement CA4520-99-007 with the University of Rhode Island. Views, 

statements, findings, conclusions, recommendations, and data in this report are those of the 

author(s) and do not necessarily reflect views and policies of the National Park Service, U.S. 

Department of the Interior. Mention of trade names or commercial products does not constitute 

endorsement or recommendation for use by the National Park Service.

This report is available from the Northeast Region’s Science website 

(http://www.nps.gov/nero/science) and the Natural Resource Publications Management website 

(http://www.nature.nps.gov/publications/NRPM).

Please cite this publication as:

James-Pirri, M. J., J. Burgess, C. T. Roman, and M. Albert. 2010. Restoration of the Turning 

Basin and Tidal Wetlands at Saugus Iron Works National Historic Site: 2008 Post-Restoration 

Monitoring Data Report. Natural Resource Data Series NPS/NER/SAIR/NRDS—2010/054. 

National Park Service, Philadelphia, PA. 

NPS 444/103375, June 2010
iii

Contents

Page

Figures................................................................................................................................. v

Tables ................................................................................................................................. vi

Abstract ............................................................................................................................ viii

Introduction ......................................................................................................................... 1

Biological Variables: Marsh and Aquatic Vegetation ........................................................ 3

Methods: Marsh and Aquatic Vegetation ....................................................................... 3

Results: Marsh Vegetation .............................................................................................. 3

Results: Aquatic Vegetation ........................................................................................... 6

Results: Invasive Plant Species ....................................................................................... 7

Biological Variables: Nekton Community.......................................................................... 9

Methods: Nekton ............................................................................................................. 9

Results: Pre-restoration Nekton ...................................................................................... 9

Results: Post-restoration Nekton................................................................................... 13

Biological Variables: Bird Community ............................................................................ 19

Methods: Bird Community ........................................................................................... 19

Results: Bird Community ............................................................................................. 19

Biological Variables: Mammals and other Wildlife ......................................................... 20

Biological Variables: Mammals and other Wildlife ......................................................... 21

Methods: Mammals and other Wildlife ........................................................................ 21

Results: Mammals and other Wildlife .......................................................................... 21

Physical Variables and Others (Monitored by CH2MHill) .............................................. 23
iv

Methods: Tidal Hydrology ............................................................................................ 23

Results: Tidal Hydrology-water surface elevation ....................................................... 23

Results: Tidal Hydrology-salinity ................................................................................. 23

Methods: River Geomorphology and Sediment Composition ...................................... 27

Results: River Geomorphology and Sediment Composition ........................................ 27

Methods: Sediment Analyses and Water Quality ......................................................... 27

Results: Sediment Analyses and Water Quality ........................................................... 30

Methods: Benthic Invertebrate Community.................................................................. 30

Results: Benthic Invertebrate Community .................................................................... 30

Literature Cited ................................................................................................................. 35
v 

Figures

Page

Figure 1. Location of pre-restoration nekton and vegetation sampling stations at Saugus 

Iron Works NHS in 2004. ................................................................................................... 4

Figure 2. Percent catch of dominant nekton sampled from throw traps at SAIR in 2008 

and 2004 ............................................................................................................................ 12

Figure 3. Average length (mm ± SD) of nekton sampled at SAIR with throw traps and 

seines in 2004 and 2008. Number of individuals measured indicated above bars. Average 

adult length (mm) is given under each species name for reference. Only species where 

more than five individuals were sampled (both years combined) are shown. .................. 12

Figure 4. Location of post-restoration nekton sampling stations at Saugus Iron Works 

NHS in 2008. .................................................................................................................... 15

Figure 5. Location of water quality monitoring instruments in 2008 (figure excerpted 

from CH2MHill 2009). ..................................................................................................... 24

Figure 6. Water surface elevation and salinity at the turning basin in 2008 (figure 

excerpted from CH2MHill 2009)...................................................................................... 25

Figure 7. Water surface elevation and salinity at Hamilton Street in 2008 (figure 

excerpted from CH2MHill 2009)...................................................................................... 26

Figure 8. Cross-sections of river channel (figure excerpted from CH2MHill 2009). ...... 28

Figure 9. Pebble count and benthic invertebrate sampling stations in 2008 (figure 

adapted from CH2MHill 2009). ........................................................................................ 29
vi 

Tables 

Page

Table 1. Species list, average Braun-Blanquet score, and average percent composition (in 

parentheses, estimated from mid-point of Braun-Blanquet scores) for vegetation sampled 

at Saugus Iron Works NHS in 2004 prior to restoration activities. .................................... 5

Table 2. Species list, average Braun-Blanquet score, and percent of plots species was 

observed for aquatic vegetation sampled at Saugus Iron Works NHS in 2004 (prerestoration) and 2008 (post-restoration).............................................................................. 6

Table 3. List of invasive and introduced plants observed during sampling. Status 

information is from USDA Plants Database and the Massachusetts Invasive Plant 

Working Group (MIPAG 2005).......................................................................................... 7

Table 4. Nekton species sampled during pre-restoration monitoring (2004) and postrestoration monitoring (2008) at Saugus Iron Works NHS. ............................................. 10

Table 5. Nekton density (number m-2 ± SD) and total number of individuals captured (in 

parentheses) from 1m2 throw trap sampling at Saugus Iron Works NHS in 2004 (prerestoration) and 2008 (post-restoration)............................................................................ 11

Table 6. Nekton species composition, average abundance per seine haul, and total 

number of individuals collected (in parentheses) with a seine at Saugus Iron Works NHS 

in 2004 (pre-restoration) and 2008 (post-restoration). ...................................................... 13

Table 7. List of exotic and native transplant (native species to the U.S. that have been 

introduced into areas outside of their original range) nekton species. Status information is 

from the USGS Nonindigenous Aquatic Species Database. ............................................. 14

Table 8. Environmental data (average ± SD) associated with nekton throw trap sampling. 

Sample size is given after location. ................................................................................... 17

Table 9. Bird species observed in July 2008. ................................................................... 20

Table 10. Pebble count size distribution (table excerpted from CH2MHill 2009). ......... 30

Table 11. Comparison of pre- and post-restoration average concentrations of detected 

metals. One-half of reporting limit used for non-detected samples in calculating the 

average concentration (table excerpted from CH2MHill 2009; units were not provided in 

the report). ......................................................................................................................... 31

Table 12. Benthic invertebrate species abundance from 2008 sampling (table excerpted 

from CH2MHill 2009). ..................................................................................................... 31
vii 

Table 13. Average number of benthic invertebrates, average number of taxa, and 

diversity index at each of the sample stations from 2008 sampling (table excerpted from 

CH2MHill 2009). .............................................................................................................. 32

Table 14. Benthic invertebrate community at each of the sample stations for 2004 and 

2008 (data excerpted from CH2MHill 2009). Comparisons with 2004 samples are only 

for the five dominant taxa (n/a notation). ......................................................................... 32
viii

Abstract

The National Park Service initiated a restoration project at Saugus Iron Works National 

Historic Site to restore the historic turning basin and wetland area adjacent to the Saugus 

River in 2007. To fulfill regulatory requirements and enhance understanding of 

freshwater wetland restoration practices, an intensive, pre- and post-restoration 

monitoring program was implemented. This report summarizes monitoring data collected 

prior to the restoration and the first year (2008) after restoration. Data summaries 

included in this report describe the status of biotic (e.g., vegetation, nekton, avian,

benthic invertebrate, and vegetation communities) and abiotic parameters (e.g., tidal 

hydrology, river geomorphology, sediment, and water quality). This is first of several 

monitoring reports associated with the restoration of the turning basin and wetlands at 

Saugus Iron Works National Historic Site. 
1 

Introduction 

Restoration of the historic condition and ecological functions of the Saugus Iron Works 

National Historic Site turning basin and southern marsh area was initiated in fall 2007. 

To fulfill regulatory requirements and enhance understanding of freshwater wetland 

restoration practices, the National Park Service (NPS) implemented a 5-year, postrestoration, intensive ecosystem research and monitoring program that began in the fall of 

2008. The monitoring program is conducted by contractors, NPS staff, and University 

cooperators. 

This report summarizes the first year of post-restoration monitoring for a wide variety of 

biological and physical parameters at Saugus Iron Works National Historic Site (SAIR).

This summary report includes data collected by the University of Rhode Island, 

CH2MHill, and the NPS during the 2008 monitoring period. Information on physical and 

biological variables (tidal hydrology, river geomorphology, sediment composition, water

quality, and benthic invertebrate community) has been excerpted from the draft 2008 

Monitoring Data Report submitted to the NPS by CH2MHill (CH2MHill 2009).

Information from the 2004 monitoring report of vegetation and nekton conducted in 

conjunction with the NPS Inventory and Monitoring Program (James-Pirri 2004) has 

been excerpted and is included in this report in an effort to describe the pre-restoration 

conditions for vegetation and nekton. In subsequent monitoring years, statistical analyses 

will be performed to compare year-to-year changes in the monitored parameters; 

however, with just one season of post-restoration monitoring data it is premature to 

pursue these analyses in this data report. Data from the Massachusetts Division of Marine 

Fisheries annual smelt and eel sampling on the Saugus River will also be incorporated 

into the monitoring assessment in subsequent years. 

Saugus Iron Works National Historic Site, located approximately 10 miles north of 

Boston on the upper reaches of the Saugus River, preserves the site of the first sustained 

ironworks of North America. The ironworks produced iron products from 1646 to 1668 

and was critical in the development of America’s iron manufacturing legacy (NPS 2006). 

Raw materials were delivered to the ironwork’s wharf by shallow draft boats navigating 

the Saugus River while finished products were transported back down the river bound for 

Boston and beyond (NPS 2006). 

In the late 1950’s, a breach of an upstream dam caused extensive sedimentation and 

siltation of the historic turning basin, waterfront, and wharf area of the ironworks (NPS 

2006). Over time the silted turning basin was colonized by invasive species and the 

southern marsh lining the Saugus River became choked with undesirable vegetation such 

as Phragmites australis (common reed) and other exotic species (Agius 2003, CH2MHill

2005). The Saugus River is a pivotal landscape feature of the historic setting and cultural 

interpretation of the Park, and in the fall of 2007 a restoration was initiated to restore the 

turning basin and remove much of the invasive vegetation from the marsh bordering the 

river. The goals of the restoration included removing sediment within the turning basin to 

restore the open water condition, removing invasive exotic plant species, improving 
2 

water quality, replacing the wharf and bulkhead, and making the river a more suitable 

nursery for aquatic and terrestrial organisms (CH2MHill 2005). This is one of the first 

tidal freshwater wetland restoration projects in New England. 

To satisfy regulatory requirements, guide any necessary adaptive management actions, 

and to enhance understanding of tidal freshwater wetland restoration practices, the NPS, 

in collaboration with university researchers and a contractor, will study the restoration 

area for 5 years. Research and monitoring will follow protocols developed and utilized by 

the NPS Northeast Coastal and Barrier Network, NPS Northeast Temperate Network, and 

the environmental firm CH2MHill (2005). Data collected from 2008 to 2012 will be 

compared to baseline pre-restoration conditions. This data report summarizes the first 

year of data for post-restoration monitoring conducted in 2008. 
3 

Biological Variables: Marsh and Aquatic Vegetation

Methods: Marsh and Aquatic Vegetation

Vegetation of the restoration area (turning basin and southern salt marsh area) will be 

evaluated following protocols of the NPS Northeast Coastal and Barrier Network (Roman 

et al. 2001, James-Pirri and Roman in review). Vegetation, including intertidal freshwater 

marsh and submerged aquatic vegetation, will be sampled once per year at the end of the 

growing season in late summer/early fall for the years 2008 through 2012 (five 

successive years). Vegetation will be sampled in a minimum of 30, 1-m2 plots that will be 

randomly located throughout the restoration area. Data recorded for each 1-m

2 plot will 

include species composition and species cover/abundance. Estimates of percent cover 

will be determined using the Braun-Blanquet (1965) visual cover scale method. For this 

method the observer stands over the plot and visually estimates the cover of each species 

present within the plot. Cover is estimated within standard cover classes as follows (0: 

absent; 1: <1%; 2: 1-5%; 3: 6-25%; 4: 26-50%; 5: 51-75%; 6: 76-100%). In statistical 

analyses the Braun-Blanquet data are analyzed as ordinal data. Multivariate statistical 

techniques, including Analysis of Similarities (ANOSIM) among others, will be used to 

evaluate responses of the vegetation community to the restoration actions. 

Results: Marsh Vegetation

Vegetation monitoring did not occur in 2008 as the planting of vegetation on the restored 

marsh was not completed until September 2008, and sampling would have negatively 

impacted the newly planted vegetation. Additionally, vegetation monitoring will be more 

informative after the planted vegetation has had one growing season to establish itself. 

Pre-restoration vegetation monitoring was conducted on 13 July 2004 as part of the NPS 

Inventory and Monitoring Program. A total of 30 vegetation plots were randomly located 

along seven transects. Four transects (16 plots) were randomly placed in the marsh area 

of the former turning basin with the remaining three transects (14 plots) placed within the 

southern area marsh adjacent to the Saugus River (Figure 1). For ease of comparison with 

future vegetation data, the data from the former turning basin area and southern section of 

the marsh are presented separately (Table 1). 

Pre-restoration vegetation of the former turning basin area (transects 1-4) was very 

complex, with a total of 23 species identified. Narrowleaf cattail (Typha angustifolia) was 

the dominant species representing 17% of the vegetation community of the marsh

(estimated from mid-point of Braun-Blanquet scores, Table 1). 

Prior to restoration, the southern marsh (transects 5-7) was dominated by common reed 

(Phragmites australis) which comprised approximately 44% of vegetation community. 

Narrowleaf cattail was also abundant, comprising 17% of the vegetation. A total of 13 

species were identified in this area (estimated from mid-point of Braun-Blanquet scores, 

Table 1).
4 

Figure 1. Location of pre-restoration nekton and vegetation sampling stations at Saugus Iron 

Works NHS in 2004.

SAIR 

Boundary

Hamilton St. Bridge

Aquatic vegetation sampling plots (n=12)

N

2004 Sampling Locations 

Vegetation sampling plots (n=30) 

Nekton throw trap sampling locations (n=16 each on 2 dates)

Seine haul locations (n=7, on 3 separate dates)
5 

Table 1. Species list, average Braun-Blanquet score, and average percent composition (in 

parentheses, estimated from mid-point of Braun-Blanquet scores) for vegetation sampled at 

Saugus Iron Works NHS in 2004 prior to restoration activities. Transects 1-4 correspond to the 

upland area formerly in the turning basin and transects 5-7 correspond to the southern section of 

the marsh adjacent to the river. 

Average Braun-Blanquet2 score 

(percent of total cover)

Common Name Scientific Name

2004

Turning Basin 

Transects 1-4 

(n=16)

2004

Lower marsh 

Transects 5-7 

(n=14)

American black nightshade Solanum americanum 0.1 (0.9%) -

American bur-reed Sparganium americanum 0.3 (2.3%) 0.1 (1.5%)

Arrow arum Peltandra virginica 1.1 (8.1%) 0.6 (6.8%)

Black locust1 Robinia pseudoacacia 0.3 (2.3%) -

Bluejoint reedgrass Calamagrostis canadensis 0.1 (0.9%) -

Climbing hempvine Mikania scandens 0.5 (3.6%) 0.1 (1.5%)

Common boneset Eupatorium perfoliatum 0.4 (3.2%) -

Common reed1 Phragmites australis 0.2 (1.4%) 4.1 (43.6%)

Comon rush Juncus effusus 0.2 (1.4%) - 

Curly dock Rumex crispus 0.1 (0.9%) -

Dotted smartweed Polygonum punctatum 0.1 (0.9%) 0.1 (1.5%)

Estuary beggarticks Bidens tripartita 0.1 (0.9%) -

Hedge bindweed Calystegia sepium 1.3 (9.0%) 0.4 (4.6%)

Jewelweed Impatiens capensis 1.3 (9.0%) 0.1 (1.5%)

Litter litter 1.0 (7.2%) 0.3 (3.0%)

Mud mud or bare 1.4 (9.9%) 0.2 (2.3%)

Multiflora rose1 Rosa multiflora 1.0 (7.2%) -

Narrowleaf cattail Typha angustifolia 2.9 (17.1%) 1.6 (16.5%)

Pickerelweed Pontederia cordata 0.3 (1.8%) 0.1 (1.5%)

Poison ivy Toxicodendron radicans 0.1 (0.9%) 0.3 (3.0%)

Polygonum species Polygonum species 0.3 (2.3%) 0.1 (1.5%)

Purple loosestrife1 Lythrum salicaria 0.6 (4.1%) 0.8 (8.3%)

Reed canary grass1 Phalaris arundinacea 0.4 (3.2%) 0.3 (3.0%)

Sweetscented joepyeweed Eupatorium purpureum 0.3 (1.8%) -

Water starworts Callitriche species 0.1 (0.5%) -

1 Invasive species as identified by the Massachusetts Invasive Plants Advisory Group (MIPAG) (2005). 2

 Braun-Blanquet cover class scale (0; 1: <1; 2: 1%- 5%; 3: 6-25%; 4: 26-50%; 5: 51-75%; 6: 76-100%).

“-” Species not present.
6 

Results: Aquatic Vegetation

Submerged aquatic vegetation cover within the river was estimated in 12 plots on 12 July

2004. These plots were located adjacent to the 2004 nekton sampling stations. The 

dominant aquatic vegetation in the river in 2004 was horned pondweed (Zannichella 

palustris) which had an average cover of 16% (estimated from mid-point of BraunBlanquet scores) and was found in five of the 12 plots (42%). Curly pondweed 

(Potamogeton crispus), an invasive species (Massachusetts Invasive Plant Advisory 

Group [MIPAG] 2005), was observed within four of the 12 plots. Other aquatic species 

that were present were Callitriche species and green alga. Forty-two percent (five plots) 

of the aquatic vegetation plots had no aquatic vegetation (Table 2). 

In 2008, aquatic vegetation was estimated during the nekton throw trap sampling (18 and 

23 September 2008). The only species of aquatic vegetation found in the river was

horned pondweed. This species had an average cover of 9% (estimated from mid-point of 

Braun-Blanquet scores) and was found in three of the 15 plots (20%) (Table 2). In the 

newly restored turning basin, four aquatic vegetation species were present. The three 

dominant species were Elodea species, horned pondweed, and curly pondweed. Horned 

pondweed and Elodea species were present in 55% and 45% of the sampled plots, 

respectively; and their cover ranged from 8% to 12% (estimated from mid-point of 

Braun-Blanquet scores) (Table 2). Curly pondweed, an invasive species, was present in 

27% of the plots and had an average cover of 7% (estimated from mid-point of BraunBlanquet scores). An unknown pondweed (Potamogeton species) was observed in one of 

the plots in the restored turning basin. 

Table 2. Species list, average Braun-Blanquet1 score, and percent of plots species was 

observed for aquatic vegetation sampled at Saugus Iron Works NHS in 2004 (pre-restoration)

and 2008 (post-restoration). Aquatic vegetation was sampled in the river adjacent to 2004 nekton 

sampling stations. 

Average Braun-Blanquet score and 

percent of plots observed

Common Name Scientific Name

2004

River

(n=12)

2008

River

(n=15)

2008

Basin

(n=11)

Curly pondweed1 Potamogeton crispus 0.6 (33%) - 1.0 (27%)

Green algae Green algae species 0.7 (17%) - - 

Elodea species Elodea species - - 1.8 (55%)

Horned pondweed Zannichella palustris 1.5 (42%) 0.9 (20%) 1.2 (45%)

Water starwort species Callitriche species 0.3 (17%) - - 

Unknown pondweed species - - 0.2 (9%)

1 Invasive species as identified by the Massachusetts Invasive Plants Advisory Group (MIPAG) (2005). 2 Braun Blanquet cover class scale (0; 1: <1; 2: 1%- 5%; 3: 6-25%; 4: 26-50%; 5: 51-75%; 6: 76-100%).

“-” Species not present.
7 

Results: Invasive Plant Species

Six invasive and/or introduced plant species were encountered at SAIR during this 

monitoring program (USDA 2004, MIPAG 2005). All six species were observed in 2004, 

but only one of these species (P. crispus) was observed in 2008 (Table 3). Agius (2003) 

encountered several additional invasive species during his survey of the park. The 

restoration of the turning basin and wetland adjacent to the Saugus River has presumably 

eradicated these species in the restored sections; however, some invasive species likely 

persist in the remaining areas of the park not influenced by the restoration (e.g., upland 

forest and manicured landscapes). These plants have spread into native and minimally 

managed plant systems in Massachusetts. They have the potential to cause economic or 

environmental harm by developing self-sustaining populations and becoming dominant 

and/or disruptive to systems where they are established (MIPAG 2005). 

Table 3. List of invasive and introduced plants observed during sampling. Status information is 

from USDA Plants Database and the Massachusetts Invasive Plant Working Group (MIPAG 

2005). Note: wetland/marsh vegetation was not monitored in 2008.

Common Name Scientific Name Status Year Observed

Black locust Robinia pseudoacacia invasive 2004

Common reed Phragmites australis invasive 2004

Curly pondweed Potamogeton crispus invasive 2004, 2008

Multiflora rosa Rosa multiflora introduced, invasive 2004

Purple loosestrife Lythrum salicaria introduced, invasive 2004

Reed canary grass Phalaris arundinacea invasive 2004
8 
9 

Biological Variables: Nekton Community

Methods: Nekton 

The nekton community of the turning basin and the Saugus River were monitored 

following protocols of the NPS Northeast Coastal and Barrier Network (Raposa and 

Roman 2001, James-Pirri et al. in review). Nekton will be sampled twice per year – once 

in mid-summer and once in late summer/early fall – for the years 2008 (late summer 

only), 2009, 2010, and 2012 on low or ebbing tides. Quantitative data on nekton 

composition and abundance (density) were collected using a 1-m2 throw trap at a 

minimum of 15 stations randomly located throughout the turning basin-river system. The 

throw trap is an enclosure sampler that has excellent efficiency and provides quantitative, 

repeatable results (Kushlan 1981, Sogard and Able 1991, Rozas and Minello 1997). The 

trap has an open top and bottom, is 0.5-m in height and 1-m square, and the sides are 

covered with 3-mm (1/8 in) wire mesh. The trap is thrown into water, imbedding it in the 

bottom sediments, and capturing any nekton within the 1-m2 area of the trap. All nekton 

are collected from the trap with a 1-mm mesh dip net that fits snuggly within the trap. 

The trap is considered empty when three successive attempts with the dip net produce no 

organisms. 

Qualitative samples of nekton were collected using a seine (6-m seine with bag, 3-mm 

mesh) at a minimum of five random locations throughout the turning basin and river 

system as ancillary information on the nekton community. Seine hauls were taken in an 

attempt to catch faster swimming fishes that may not be adequately sampled by the throw 

trap in order to achieve a more complete species list.

 At each station, all fish and decapods were identified and enumerated. A representative 

number (up to 15 individuals) of each species collected was measured for length (total 

length for fish and shrimp, carapace width for crabs). Once identified and measured all 

organisms were returned to the water. Multivariate statistical techniques, including 

Analysis of Similarities (ANOSIM) will be used to evaluate responses of the nekton 

community to the restoration actions. 

Physical variables (water temperature [o

C], salinity [ppt], and dissolved oxygen [mg/L]) 

were recorded at each nekton sampling station with a YSI unit (model 85) at the time of 

sampling.

Results: Pre-restoration Nekton

Pre-restoration nekton throw trap sampling occurred on 9 June and 5 August 2004 in the 

Saugus River. A total of 16 stations were sampled during each day. Seven seine hauls 

were made on three separate days in 2004 (5 August, 11 August, and 2 September) at two 

locations in the river. Two hauls (on 11 August) were made in the upper portion of the 

Saugus River and the other five (on 5 August, 11 August, and 2 September) were made 

immediately north of the Hamilton Street Bridge (Figure 1). 

During the 2004 pre-restoration sampling, 13 species (11 fish and two decapods) were 

sampled using seine and throw traps (Table 4). 
10 

Table 4. Nekton species sampled during pre-restoration monitoring (2004) and post-restoration 

monitoring (2008) at Saugus Iron Works NHS.

Pre-restoration

(2004)

River only 

Post-restoration

(2008) 

River & Basin

Common Name Scientific Name Seine Throw Trap Seine Throw Trap

Alewife Alosa pseudoharengus X 

American eel Anguilla rostrata X X X 

Bluegill Lepomis macrochirus X X 

Brook stickleback Culaea inconstans X X 

Four-spine stickleback Apeltes quadracus X X X X 

Green crab Carcinus maenas X 

Harris mud crab Rhithropanopeus harrisii X 

Largemouth bass Micropterus salmoides X X 

Mummichog Fundulus heteroclitus X 

Nine-spine stickleback Pungitius pungitius X X 

Redfin pickerel Esox americanus X 

Three-spine stickleback Gasterosteus aculeatus X 

White perch Morone americana X X 

White sucker Catostomus commersoni X X X X 

Total species caught 11 6 5 5 

In June, the throw trap catch was dominated by young-of-the-year white suckers 

(Catostomus commersoni) and four-spine sticklebacks (Apeltes quadracus) comprising 

77% and 13% of the catch, respectively (Table 5). American eels (Anguilla rostrata) and 

three-spine sticklebacks (Gasterosteus aculeatus) were also present and composed 9% 

and 2% of the catch, respectively. In August, juvenile white suckers and four-spine 

sticklebacks again dominated the catch with each species comprising 39% of the catch.

American eels comprised 15% of the catch and brook sticklebacks (Culaea inconstans) 

and green crabs (Carcinus maenas) each comprised 3% of the catch. More individuals 

were sampled in June, primarily due to the abundance of young-of-the-year white suckers 

(Table 5). Overall, the dominant species sampled in 2004 were white suckers (Figure 2).

The catch also consisted of young-of-the-year or juveniles for most of the species (Figure 

3).

A total of 11 species (10 fish and one decapod) were sampled using the seine in 2004 

(Table 4 and Table 6). As expected seine hauls captured the faster swimming nekton such 
11 

as alewife (Alosa pseudoharengus), largemouth bass (Micropterus salmoides), and redfin 

pickerel (Esox americanus).

Table 5. Nekton density (number m-2 ± SD) and total number of individuals captured (in 

parentheses) from 1m2 throw trap sampling at Saugus Iron Works NHS in 2004 (pre- restoration) 

and 2008 (post-restoration). Sample size is given after date.

Average Density (Number m-2 ± SD [total no. individuals])

Common Name

Scientific name

River 

June 2004 

n = 16

River

Aug 2004

n = 16

River 

Sept 2008

n=15

Turning Basin

Sept 2008

n=11

American eel

Anguilla rostrata

1.6 ± 2.6 (25) 0.3 ± 1.0 (5) 0.2 ± 0.4 (3) 2.6 ± 3.3 (29)

Brook stickleback

Culaea inconstans

0 0.1± 0.3 (1) 0 0

Bluegill

Lepomis macrochirus

0 0 0 0.9 ± 1.4 (10)

Four-spine stickleback

Apeltes quadracus

2.3 ± 4.9 (37) 0.8 ± 1.4 (13) 0.6 ± 1.6 (9) 1.4 ± 1.9 (15)

Green crab

Carcinus maenas

0 0.1 ± 0.3 (1) 0 0 

Nine-spine stickleback

Pungitius pungitius

0 0 0.5 ± 2.1 (8) 0.09 ± 0.3 (1)

Three-spine stickleback

Gasterosteus aculeatus

0.4 ± 1.5 (6) 0 0 0 

White sucker

Catostomus commersoni

13.9 ± 20.9 (223) 0.8 ± 2.5 (13) 0.07 ± 0.3 (1) 0

Total Nekton Density 18.2 ± 26.9 (291) 2.1 ± 3.2 (33) 1.4 ± 3.0 (21) 5.0 ± 3.3 (55)
12 

0%

10%

20%

30%

40%

50%

60%

70%

80%

9-spine

stickleback

4-spine

stickleback

American eel Bluegill White sucker

Percent of Catch

Basin, 2008

River, 2008

River, 2004

0

20

40

60

80

100

120

Average length (mm + SD) 

2004

2008

3 spine 

stickleback

(75 mm)

American eel

(600 mm)

6

50

4 spine 

stickleback

(100 mm)

29

2

4

White sucker

(450 mm)

32

40

42

0

Bluegill

(250 mm)

62

Largemouth bass

(500 mm)

7

. 

Figure 3. 

Figure 2. Percent catch of dominant nekton sampled from throw traps at SAIR in 2008 and 2004

Figure 3. Average length (mm ± SD) of nekton sampled at SAIR with throw traps and seines in 

2004 and 2008. Number of individuals measured indicated above bars. Average adult length (mm) 

is given under each species name for reference. Only species where more than five individuals 

were sampled (both years combined) are shown.
13 

Table 6. Nekton species composition, average abundance per seine haul, and total number of 

individuals collected (in parentheses) with a seine at Saugus Iron Works NHS in 2004 (prerestoration) and 2008 (post-restoration). 

Two nonindigenous (non-native) fish species, brook stickleback and largemouth bass, 

and one exotic crustacean (green crab) were sampled in 2004 (Table 7). Both of the fish 

species are native to North America but are introduced to Massachusetts (Fuller 2004a, 

2004b, USGS 2009). The green crab is a well established exotic species (first recorded 

observation on the East Coast in 1817) that is abundant in coastal waters from Maine to 

Maryland (Benson 2004). Introductions have had a negative impact on soft-shell clams, 

young oysters, and native crabs in the Northeast beginning in the 1950s (Benson 2004). 

Results: Post-restoration Nekton

The first post-restoration nekton sampling event occurred on 18 September 2008 (turning 

basin samples) and 23 September 2008 (river samples). Since construction activities were 

not completed until late summer, only the late summer nekton sampling was conducted. 

Twenty-six throw trap stations were sampled (11 stations in the basin, 15 in the river) 

(Figure 4). Nine seine stations (three in the turning basin and six in the river) were also 

sampled on these two days. 

Average abundance per haul (total catch)

Common Name

Scientific Name

2004

Upper portion of 

river

n = 2

2004

Adjacent to 

Hamilton St. 

Bridge 

n=5

River 

2008

n=6

Turning

Basin 2008

n=3

Alewife

Alosa pseudoharengus 2.5 (5) 0.2 (1) 0 0 

American eel

Anguilla rostrata 0.5 (1) 0 (0) 0 0 

Bluegill

Lepomis macrochirus 0 0 0.2 (1) 14.0 (42)

Brook stickleback

Culaea inconstans 1.5 (3) 15.2 (76) 0 0 

Four-spine stickleback

Apeltes quadracus 4 (8) 23.4 (117) 2.2 (13) 5.7 (17)

Harris mud crab

Rhithropanopeus harrisii 0 0.2 (1) 0 0 

Largemouth bass

Micropterus salmoides 0 0.8 (4) 0.3 (2) 2.0 (6)

Mummichog

Fundulus heteroclitus 0 1.2 (6) 0 0 

Nine-spine stickleback

Pungitius pungitius 0 0.4 (2) 0 0 

Redfin pickerel

Esox americanus 0 0.2 (1) 0 0 

White perch 

Morone americana 0 0.6 (3) 0 0.3 (1)

White sucker

Catostomus commersoni 1 (2) 168.2 (841) 0 15.7 (47)

Avg. total abundance per haul 9.5 (19) 210.4 (1052) 2.6 (16) 37.7 (113)
14 

Table 7. List of exotic and native transplant (native species to the U.S. that have been introduced 

into areas outside of their original range) nekton species. Status information is from the USGS 

Nonindigenous Aquatic Species Database. 

Scientific Name Common Name Status Year Observed

Bluegill Lepomis macrochirus Native transplant 2008

Brook stickleback Culaea inconstans Native transplant 2004

Green crab Carcinus maenas Exotic 2004

Largemouth bass Micropterus salmoides Native transplant 2004, 2008
15 

N 2008 Sampling Locations

Seine station (n=9)

Bird observation stations 

Throw trap stations (n=26)

Figure 4. Location of post-restoration nekton sampling stations at Saugus Iron 

Works NHS in 2008.
16 

In 2008, seven nekton species were collected using both throw trap and seine in the 

restored turning basin and the Saugus River (Table 4). Only three of these species, the

bluegill (Lepomis macrochirus), four-spine stickleback, and white sucker were caught in 

both the throw trap and the seine. 

In the river, four-spine sticklebacks and nine-spine sticklebacks dominated the throw trap 

samples comprising 43% and 38% of the catch, respectively. American eels comprised 

14% of the catch and white suckers comprised the remaining 5% of the catch (Table 5, 

Figure 3). The seine samples from the river stations were also dominated by four-spine 

sticklebacks (81% of the catch). Other species sampled with the seine in the river 

included largemouth bass (13% of the catch) and bluegill (6% of the catch) (Table 6). 

Similar to 2004, the majority of fish sampled in 2008 were young-of-the-year or juveniles 

(Figure 4).

In the newly restored turning basin, American eels (all juveniles, average length 69 mm, 

Figure 4) dominated the throw trap samples comprising 53% of all species caught. Fourspine sticklebacks comprised 27% of the catch and bluegills comprised 18% of the catch. 

Nine-spine sticklebacks comprised the remaining 2% of the throw trap catch in the 

turning basin (Table 5, Figure 3). In the seine samples, white suckers (42% of the catch) 

and bluegill (37% of the catch) dominated the catch in the turning basin. Four-spine 

sticklebacks comprised 15% of the catch with largemouth bass (5%) and white perch 

(1%) making up the remainder of the samples (Table 6). The high incidence of American 

eels in the throw trap samples in the turning basin is likely due to the ability of the gear to 

sample the benthic sediment layer where these individuals are located.

In 2008, an additional non-native species, the bluegill, was collected (Table 7). The 

bluegill is a native transplant and it was not present in the 2004 fish samples. This species 

was most likely transplanted into Massachusetts waters by intentional stocking programs

(USGS 2009). 

Water temperature, salinity, and dissolved oxygen collected in conjunction with the 

nekton sampling events were similar between 2004 and 2008 (Table 8).
17 

Table 8. Environmental data (average ± SD) associated with nekton throw trap sampling. 

Sample size is given after location.

Variable Water 

Temperature

(°C)

Salinity

(ppt) 

Dissolved 

oxygen

(mg l-1)

June 9, 2004 (n=16) (river) 21.5 ± 1.4 0.3 ± 0.04 7.4 ± 0.5

Aug 5, 2004 (n=16) (river) 19.9 ± 0.8 0.1 ± 0.1 7.5 ± 0.5

Sept 18, 2008 (n=12) (turning basin) 18.4 ± 0.8 0.5 ± 0.8 8.3 ± 1.3

Sept 23, 2008 (n=1) ( turning basin ) 20.6 0.2 6.5

Sept 23, 2008 (n=21) (river) 14.7 ± 0.4 0.3 ± 0.0 9.4 ± 0.2
18 
19 

Biological Variables: Bird Community

Methods: Bird Community

Bird utilization of the restoration area will be monitored by volunteers following the 

guidelines of the NPS Northeast Temperate Network (NETN) Breeding Bird Monitoring 

Protocol (NPS 2007). Birds will be monitoring using the variable circular plot point 

counts at three observation stations (Figure 2). At each station all birds seen or heard will 

be recorded during 10-minute point counts. In addition, the distance from the observer to 

each bird will be estimated within distance bands (0-10 m, 11-25 m, 25-50 m, >50 m) so 

detection probabilities can be estimated. Birds will be surveyed twice annually, with 

replicates occurring about 7-14 days apart (NPS 2007). Bird observations will be 

conducted by volunteers and the NPS will coordinate the scheduling of volunteers. Data 

analyses and interpretation will be conducted by the University of Rhode Island. 

Results: Bird Community

Birds were sampled on 11 July 2008. During this sampling event, a total of 21 species 

were recorded (Table 9). One species, Baltimore oriole (Icterus galbula) is listed by 

Partners in Flight (PIF) as “IA: High Continental Priority, High Regional Responsibility”, 

indicating that conservation of this species in southern New England is critical to the 

overall health of the species (Dettmers and Rosenberg 2000). 
20 

Table 9. Bird species observed in July 2008. 

1 Partner in Flight “High Continental Priority, High Regional Responsibility” species. 

Common Name Scientific Name Number of 

detections

American Crow Corvus brachyrhynchos 3 

American Robin Turdus migratorius 2 

Baltimore Oriole1 Icterus galbula 1 

Barn Swallow Hirundo rustica 2 

Belted Kingfisher Ceryle alcyon 1 

Blue Jay Cyanocitta cristata 2 

Common Grackle Quiscalus quiscula 1 

Common Yellowthroat Geothlypis trichas 1 

Downy Woodpecker Picoides pubescens 2 

European Starling Sturnus vulgaris 2 

Gray Catbird Dumetella carolinensis 2 

Herring Gull Larus argentatus 1 

House Sparrow Passer domesticus 3 

Mallard Anas platyrhynchos 1 

Mourning Dove Zenaida macroura 1 

Northern Cardinal Cardinalis cardinalis 3 

Northern Flicker Colaptes auratus 1 

Red-winged Blackbird Agelaius phoeniceus 1 

Rock Dove Columba livia 1 

Song Sparrow Melospiza melodia 3 

Tufted Titmouse Baeolophus bicolor 1 
21 

Biological Variables: Mammals and other Wildlife 

Methods: Mammals and other Wildlife

Sightings of mammals and other wildlife incidentally observed during the course of 

monitoring activities will be recorded and sightings from other observers (e.g., park staff, 

consulting contractor) will be compiled. Beginning in summer 2009 park staff began 

implementing a systematic wildlife observation program, collecting observations from all 

tide conditions, times of day, and locations in and adjacent to the project area. 

Results: Mammals and other Wildlife

In 2004, a large snapping turtle (Macrochelys temminckii) was seen during nekton 

sampling in the upper portion of the river in the area where the restored turning basin and 

river intersect (James-Pirri personal observation). 
22 
23 

Physical Variables and Others (Monitored by CH2MHill) 

CH2MHill conducted and analyzed parameters associated with tidal hydrology, river 

geomorphology, sediment and water quality, and benthic invertebrate community in 2008 

(post-restoration). The following is a brief summary of the analyses that were excerpted 

from the draft 2008 Monitoring Data Report prepared by CH2MHill in February 2009. 

No new analyses are presented. This summary is not meant to replace the CH2MHill 

Data Report, but is presented with the intent of providing an integrated post-restoration 

monitoring summary. The CH2MHill Data Report (CH2MHill 2009) should be referred 

to if more detail is desired. 

Methods: Tidal Hydrology

The tidal hydrology was monitored using two remote water quality meters (YSI, model 

6600V2 data sonde) in the Saugus River deployed between 7 October 2008 and 18 

November 2008 (Figure 5). The instrument recorded data (water level, specific 

conductance/salinity, dissolved oxygen, temperature, pH, and turbidity) at 15-minute 

intervals. 

Results: Tidal Hydrology-water surface elevation

The water surface elevation of the turning basin fluctuated between approximately 1.5 ft 

and 4 ft between high and low tides over the monitoring period with the trend following 

the lunar cycles of high and low tide (Figure 6). This pattern was somewhat confounded 

by increased river discharge during lower magnitude tide events. USGS stream gage data 

from the Saugus River show a pulse in discharge that coincided with two large rainfall 

events, one on 25 and 26 October and one on 6 November, which resulted in considerable 

increases in river discharge levels on these dates. 

The water surface elevation for the downstream data sonde (Hamilton Street) showed a 

diurnal fluctuation that ranged from approximately 2.5 to 8 ft between high and low tides 

during the monitoring period (Figure 7). The expected pattern of the tidal lunar cycle was 

confounded by the two large rainfall events that increased river discharge levels. 

The average water surface elevation at the upstream location (turning basin) over the 

course of the monitoring period was approximately 3.0 ft, compared to an average of 1.4 

ft at the downstream (Hamilton Street) location.

Results: Tidal Hydrology-salinity

There was little salt water intrusion into the turning basin during the first week of 

sampling (early October 2008); however, by mid to late October, high tide events brought 

higher salinity values into the area, indicating that saltwater intrusion was occurring as far 

upstream as the turning basin (Figure 6). This upstream movement of saltwater appears to 

be influenced heavily by stream flow because salinity values were low during periods of 

high stream flow. In general, the data suggests that if stream flow is higher than 

approximately 10 cfs, limited amounts of saltwater will reach the turning basin area, and 

if stream flow is less than approximately 10 cfs, saltwater will move upstream to the 

turning basin, except during neap tides. 
24 

Figure 5. Location of water quality monitoring instruments in 2008 (figure excerpted from CH2MHill 2009).
25 

25

 

Figure 6. Water surface elevation and salinity at the turning basin in 2008 (figure excerpted from CH2MHill 2009).
26 

26

 

Figure 7. Water surface elevation and salinity at Hamilton Street in 2008 (figure excerpted from CH2MHill 2009).
27 

27

In general, the salinity values for the downstream (Hamilton Street) location were 

noticeably higher for a given tide event than those at the upstream location. Similar to the 

upstream location, it appears that saltwater reaches Hamilton Street during low flow 

periods, even on neap tides, if the river discharge level remains below about 15 cfs 

(Figure 7).

Methods: River Geomorphology and Sediment Composition

A section of the Saugus River immediately downstream of Bridge Street contains 

valuable smelt spawning habitat. Monitoring changes in river channel geomorphology are 

important because river flow and bed composition can influence rainbow smelt spawning. 

Cross-sectional dimensions and substrate composition (i.e., gravel, sand, and silt/clay 

composition) of the river channel were collected at five transects across the river. 

Pebble counts were conducted for three of the five transects: Transect A, Transect C, and 

Transect 7 (Figure 8, Figure 9). Pebble counts were not conducted for Transect F and 

Transect 23 because the substrate along these transects was uniformly sand. A total of 50 

randomly selected particles were measured along each transect. The particles were 

selected by taking one step along the transect and reaching down and picking up the first 

particle touched. Particles were measured along the intermediate axis, not the longest or 

the shortest side for each particle. 

Results: River Geomorphology and Sediment Composition

The elevation changes observed within the river channel portions of the cross-sections 

demonstrate the dynamic nature of the river, as some of the bedload sediment shows 

redistribution between the 2004 and 2008 surveys (Figure 8). Cross-sections A and C 

show how the gravel bar just downstream of Bridge Street has migrated and built up on 

the west side of the channel as a result of high stream flows, likely related to the extreme 

flows that occurred in May 2006. The discharge reached a record level for the Saugus 

River of 1,420 cfs, a level that is estimated to occur once every 40 years (USGS 2006). 

Cross-sections F and 7 show a build up of bedload material in the river channel, while 

Cross-section 23 shows evidence of scouring as the elevation decreased within the 

channel at this location. These changes are likely related to the extreme flows in May 

2006, but also demonstrate the dynamic nature of rivers, where the movement and 

redistribution of bedload is a natural occurrence. 

Medium to coarse gravel dominated the substrate compositions at Transect A and 

Transect C. In contrast, the substrate along Transect 7 was characterized by finer grained 

substrate, dominated by sand and fine gravel (Table 10). 

Methods: Sediment Analyses and Water Quality

Six sediment samples were collected from 0 to 6 inches below the sediment surface to 

monitor post-restoration sediment quality. Five of the samples were collected at the 

transition point from the subtidal to intertidal zones along the five cross-sections selected 

for monitoring. 
28 

28

 

Figure 8. Cross-sections of river channel (figure excerpted from CH2MHill 2009).
29 

 

A-1 

C-1 

Figure 9. Pebble count and benthic invertebrate sampling stations in 2008 (figure adapted from CH2MHill 

2009).
30 

Table 10. Pebble count size distribution (table excerpted from CH2MHill 2009).

Number of Particles

Size Range (mm) Transect A Transect C Transect 7

<2mm: Sand 6 6 26

2 to 4mm: Very fine gravel 2 1 7

4 to 8mm: Fine gravel 6 2 15

8 to 16mm, Medium gravel 14 5 2

16 to 32mm, Coarse gravel 16 18 0

32 to 64mm, Very coarse gravel 5 17 0

64 to 90mm, Small cobble 0 1 0

90 to 128mm, Medium cobble 1 0 0

Results: Sediment Analyses and Water Quality

Chromium, copper, lead, nickel, and zinc were detected in all the sediment samples. 

Arsenic was detected in only three of the samples and was not detected in sample SD07R, where it was previously found at the highest concentration. Antimony, beryllium, 

selenium, silver, and thallium were not detected in any of the samples. Polycyclic 

Aromatic Hydrocarbons (PAHs) were not detected in three of the samples (S-23, S-C, 

and S-F). Only one PAH compound (pyrene) was detected in sample SD-07R at a 

concentration of 221 ug/kg. Only two PAH compounds (fluranthene and pyrene) were 

detected in sample S-A at concentrations of 204 and 207 ug/kg, respectively. Only one 

sample (S-7) contained several PAH compounds. The average concentrations of all the 

detected metals in the 2008 samples were consistently lower than in the pre-restoration 

samples (Table 11). Therefore, the sediment quality seems to have improved substantially 

as a result of the restoration efforts.

One surface water sample was collected from the river channel and analyzed for priority 

pollutant metals in 2008. The only metal detected in the surface water sample was zinc at 

a concentration of 0.0271 mg/L, which is below the criteria for the protection of aquatic 

life for this metal. No other metals were detected above the reporting limits.

Methods: Benthic Invertebrate Community

The benthic community was surveyed by collecting benthic community samples on 24 

September 2008 from six stations within the study area (Figure 9). Samples were 

collected from three cross-sections within the project area. Two samples were collected 

from each cross-section, one within the river channel or subtidal habitat and one from the 

transition zone from subtidal to intertidal habitat. The samples were collected using an 

Eckman dredge with a sampling surface area of 81 in2 (9 in x 9 in). Three replicate grabs 

were collected at each sampling station and sieved (500-μm mesh) in the field. Care was 

taken to replicate the sampling depth for each grab as much as possible (i.e., 3-4 in 

sample depth). The benthic samples were preserved with a 5-10% formalin solution. The 

preserved samples were shipped to Pennington & Associates, Cookeville, Tennessee for 

identification (identified to the lowest practical taxonomic level) and enumeration. 

Results: Benthic Invertebrate Community

Chironomids (order Diptera), commonly known as midges, were the most abundant 

organism in the 2008 benthic samples comprising 45% of the total number of organisms 

collected (Table 12). The second most abundant organisms were oligochaetes (majority 
31 

of individuals from the family Tubificidae), which comprised 41% of the organisms 

collected. The third most abundant organisms were amphipods (Gammarus tigrinus), 

which comprised 9% of the total number of organisms. Fourth in abundance were 

gastropods, or snails, which comprised about 3% of the total number of organisms 

collected. Eight other groups of organisms were found, but together comprised less than 

1% of the total number of organisms. 

Table 11. Comparison of pre- and post-restoration average concentrations of detected metals. 

One-half of reporting limit used for non-detected samples in calculating the average concentration 

(table excerpted from CH2MHill 2009; units were not provided in the report).

Average Concentration (mg/kg)

Detected Metal 2004

Northern Area

2004 

Southern Area

2004 

Average

2008

Average

Arsenic 14.9 13.9 14.3 2.36

Cadmium 1.45 1.53 1.5 0.589

Chromium 57.3 69.5 63.5 18.7

Copper 60.0 61.8 61.0 13.9

Lead 171.4 162.4 164.7 30.1

Mercury 0.291 0.139 0.316 0.057

Nickel 46.7 44.7 45.8 19.9

Zinc 261.4 266.7 263.7 68.7

Table 12. Benthic invertebrate species abundance from 2008 sampling (table excerpted from 

CH2MHill 2009).

Class or 

Order Family Average number (individuals m-2) 

Percent of 

total

Diptera Chironomidae 5,087 45.06

Oligochaeta Tubificida, Lumbriculida 4,671 41.37

Amphipoda Gammaridae 1,064 9.43

Gastropoda Mesogastropoda, Basommatophora 387 3.43

Bivalvia Unionoida, Veneroida 23 0.21

Ostracoda Not Identified 20 0.18

Polychaeta Nereidae, Spionidae 10 0.08

Coleoptera Elmidae 10 0.08

Isopoda Anthuridae 9 0.08

Turbellaria Tricladida 3 0.03

Hirudinea Not Identified 3 0.03

Trichoptera Leptoceridae 3 0.03

Station F-1, a sand-dominated, subtidal location, contained the greatest abundance of 

organisms of all the stations. Station 7-1, a sand and gravel, subtidal location, contained 

the greatest number of taxa and highest Shannon-Weiner Diversity index, although it had 

a relatively low abundance of organisms (Table 13). There were no distinct differences in 

these measures between the subtidal and intertidal locations, although generally the 

intertidal locations tended to have a higher abundance of organisms. 

The intertidal samples were generally dominated by chironomids (i.e., Diptera) 

(approximately 49% to 68%) in contrast to the subtidal samples where these organisms 
32 

comprised only about 16% to 31% of the organisms present (Table 14). The subtidal 

samples collected in the uniform sand substrate habitats (samples F-1 and 23-1) were 

dominated by oligochaete worms, which comprised 63% to 73% of the organisms in the 

samples. The subtidal samples collected in the sand and gravel area (sample 7-1) was the 

only sample where gastropods dominated the community, with 59% of the organisms in 

the sample. This sample also contained the highest diversity and this is likely related to 

the more diverse habitat than that of the uniform sand substrate stations. The differences 

in the benthic community composition within the various habitats are likely related to 

differences in substrate preference among species, although the dominance of 

oligochaetes, primarily tubificid worms, in two of the subtidal stations, may be an 

indicator of degraded habitat. Dominance of tubificid worms can be an indication of an 

organically enriched or polluted environment because oligochaete worms of the family 

Tubificidae are generally classified as a contaminant-tolerant indicator species.

Table 13. Average number of benthic invertebrates, average number of taxa, and diversity index 

at each of the sample stations from 2008 sampling (table excerpted from CH2MHill 2009).

Sample 

Location

Average number 

(individuals m-2)

Average number of 

Taxa

Shannon-Weiner Index

of Diversity

7-1 (subtidal) 3,419 14 2.137

7-2 (intertidal) 18,122 9 1.959

F-1 (subtidal) 18,855 8 1.422

F-2 (intertidal) 10,378 9 1.565

23-1 (subtidal) 2,673 9 1.929

23-2 (intertidal) 14,294 8 1.604

Table 14. Benthic invertebrate community at each of the sample stations for 2004 and 2008 (data 

excerpted from CH2MHill 2009). Comparisons with 2004 samples are only for the five dominant 

taxa (n/a notation).

Percent by Number of Organisms

2008 samples 2004 samples

Class or 

Order

7-1

subtidal

7-2

intertidal

F-1

subtidal

F-2

intertidal

23-1

subtidal

23-2

intertidal

Sand1Sand -2

Diptera 16.4 48.9 25.0 67.7 31.0 59.7 1.5 1.2

Oligochaeta 6.3 44.8 72.8 30.6 63.0 7.7 14.7 8.8

Amphipoda 14.4 5.0 1.6 1.5 2.1 31.3 81.9 86.6

Gastropoda 58.6 0.8 0.4 0.1 1.0 0.4 0.2 0.4

Bivalvia 1.5 0.3 0.2 - 0.2 - - 0.7

Ostracoda - - - - 0.5 0.8 n/a n/a

Polychaeta 0.4 - - - 1.0 0.1 n/a n/a

Coleoptera 0.7 0.2 - - - - n/a n/a

Isopoda - - - 0.2 1.2 - n/a n/a

Turbellaria 0.6 - - - - - n/a n/a

Hirudinea 0.6 - - - - - n/a n/a

Trichoptera 0.6 - - - - - n/a n/a

The benthic data from this survey were compared with the pre-restoration benthic data to 

determine if and how the composition of the benthic community might have changed. 

This comparison revealed that there may have been a shift in the benthic community 

structure within the sand substrate habitat since the restoration project was completed. 
33 

The dominant organisms found in the sand substrate samples in 2004 were amphipods, 

which comprised more than 80% of the organisms in the samples (Table 14). In contrast, 

amphipods were third in numerical dominance in the 2008 samples, and comprised only 

1.5% to 31.3% of the samples. The dominance of diptera in the 2008 samples is 

contrasted sharply by low abundance of these organisms in the 2004 samples (less than 

2% of the total organisms). A similar increase in the abundance of oligochaete worms 

was observed. Oligochaete worms comprised only about 9% to 15% of the organisms in 

the 2004 samples, but in contrast, comprised approximately 6% to 73% of the organisms 

in the 2008 samples. 

The apparent shift in the benthic community may be related to seasonal differences in 

benthic invertebrate abundance because the 2004 samples were collected in July and the 

2008 samples were collected in late September. However, the changes in the dominant 

species within the community might also be related to the disturbance created from the 

restoration project. The changes may represent a community in transition that has not yet 

returned to baseline conditions. Future monitoring efforts will provide data to determine 

whether this change is temporary or related to long-term water quality issues in the 

Saugus River.
34 
35 

Literature Cited

Agius, B. 2003.Forging Changes in an American landscape: Invasive plant species at the 

Saugus Iron Works National Historic Site. Technical Report NPS/NER/NRTR – 

2005/010. National Park Service, Woodstock, VT. 

Benson, A. 2004. Carcinus maenas . Nonindigenous Aquatic Species Database, 

Gainesville, FL. (http://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=190).

Accessed 11 March 2010

Braun-Blanquet, J. 1965. Plant sociology: the study of plant communities. London: 

Hafner.

CH2MHill. 2005. Restore Saugus River Turning Basin and Dock – Monitoring Plan. 

Technical Report, prepared for National Park Service, Denver Service Center, 

Denver, CO. 

CH2MHill. 2009. Draft Report – 2008 Monitoring Data Report- Restore Saugus River 

Turning Basin and Dock – Saugus Iron Works National Historic Site, Saugus 

MA., January 2009. 

Dettmers, R. and K. Rosenberg. 2000. Draft Partners in Flight landbird conservation 

plan: Physiographic Area 9: Southern New England. Version 1.0, October 2000. 

American Bird Conservancy. Ithaca, NY. 

(http://www.blm.gov/wildlife/plan/pl_09_10.pdf). Accessed 11 March 2010.

Fuller, P., 2004a. Culaea inconstans. Nonindigenous Aquatic Species Database, 

Gainesville, FL. (http://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=701). 

Accessed 11 March. 2010

Fuller, P. 2004b. Micropterus salmoides. Nonindigenous Aquatic Species Database, 

Gainesville, FL. (http://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=401). 

Accessed 11 March 2010.

 

James-Pirri, M.J. 2004. Summary of Nekton and Vegetation Sampling at Saugus Iron 

Works National Historic Site, June-August 2004. Data report submitted to the 

National Park Service dated November 11, 2004. 

James-Pirri, M.J., C.T. Roman. (In Review). Monitoring nekton in shallow estuarine 

habitats (Revision #1). A Protocol for the National Park Service’s Long-Term 

Monitoring Program, Northeast Coastal and Barrier Network. Submitted to Sara 

Stevens, National Park Service Northeast Coastal and Barrier Network.

James-Pirri, M.J., C.T. Roman, and J.F. Heltshe. (In Review). Monitoring Salt Marsh 

Vegetation (Revision #1). A Protocol for the National Park Service’s Long-Term
36 

Monitoring Program, Northeast Coastal and Barrier Network. Submitted to Sara 

Stevens, National Park Service Northeast Coastal and Barrier Network.

Kushlan, J.A. 1981. Sampling characteristics of enclosure fish traps. Transactions of the 

American Fisheries Society 110:557-562. 

Massachusetts Invasive Plant Advisory Group (MIPAG). 2005. The evaluation of nonnative plant species for invasiveness in Massachusetts (with annotated list). 

(http://www.massnrc.org/MIPAG/). Accessed 11 March 2010.

National Park Service. 2006. Restore Saugus River Turing Basin and Dock: Summary of 

Historic and Natural Resource Values. Project Synopsis July 14, 2006. Saugus 

Iron Works National Historic Site, Saugus, MA, National Park Service, U.S. 

Department of Interior. 

National Park Service. 2007. NETN Breeding Bird Vital Sign Monitoring Protocol. 

Draft. April 2007, version 2.0. 

(http://science.nature.nps.gov/im/units/NETN/downloads/Phase3/Protocol_Forest

_Breeding_Birds.pdf ). Accessed 11 March 2010.

Raposa, K.B. and C.T. Roman. 2001. Monitoring nekton in shallow estuarine habitats.

Part of a series of monitoring protocols for the Long-term Coastal Ecosystem 

Monitoring Program at Cape Cod National Seashore. USGS Patuxent Wildlife 

Research Center, Coastal Research Field Station, University of Rhode Island, 

Narragansett, RI 02882.

(http://www1.nrintra.nps.gov/im/monitor/VitalSignsDB/BrowseProtocol.aspx). 

Accessed 11 March 2010. 

(http://science.nature.nps.gov/im/monitor/protocols/caco_nekton.pdf) 

Roman, C.T., M.J. James-Pirri, and J.F. Heltshe. 2001. Monitoring Salt Marsh 

Vegetation: Part of a series of monitoring protocols for the Long-term Coastal 

Ecosystem Monitoring Program at Cape Cod National Seashore. USGS Patuxent 

Wildlife Research Center, Coastal Research Field Station, University of Rhode 

Island, Narragansett, RI 02882.

(http://www1.nrintra.nps.gov/im/monitor/VitalSignsDB/BrowseProtocol.aspx). 

Accessed 11 March 2010.

Rozas, L.P. and T.J. Minello. 1997. Estimating densities of small fishes and decapod 

crustaceans in shallow estuarine habitats: a review of sampling design with focus 

on gear selection. Estuaries 20:199-213. 

Sogard, S.M. and K.W. Able. 1991. A comparison of eelgrass, sea lettuce macroalgae, 

and marsh creeks as habitats for epibenthic fishes and decapods. Estuarine, 

Coastal and Shelf Science 33:501-519. 
37 

USDA. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Accessed 11 

March 2010. National Plant Data Center, Baton Rouge, LA 70874-4490 USA. 

USGS. 2006. U.S. Geological Survey. Flooding in Massachusetts, May 2006. USGS 

Release, May 22, 2006. (http://www.usgs.gov/newsroom/article.asp?ID=1510). 

Accessed 11 March 2010. 

USGS. 2009. Nonindigenous Aquatic Species Database. Online (http://nas.er.usgs.gov) 

Accessed 11 March 2010. 

The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and 

other information about those resources; and honors its special responsibilities to American Indians, Alaska Natives, and affiliated 

Island Communities.

June 2010
National Park Service

U.S. Department of the Interior

Northeast Region

Natural Resources and Science

200 Chestnut Street

Philadelphia, PA 19106-2878

www.nps.gov/nero/science

www.nature.nps.gov

EXPERIENCE YOUR AMERICA TM