Supplemental Environmental Impact Statement for the 

Designation of Dredged Material Disposal Site(s) in 

Eastern Long Island Sound, Connecticut and New York

APPENDIX F

Disposal Area Monitoring System – DAMOS: 

Data Summary Report of the New London 

Disposal Site and Vicinity Sediment Profile 

and Plan-View Imaging Survey 

Prepared for: United States Army Corps of Engineers

Prepared by: DAMOSVision 

March 2015
[This page intentionally left blank.] 
Data Summary Report: New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey 

September 2014 

Disposal Area 

Monitoring System 

DAMOS

Data Summary Report 

2015-01 

March 2015 
This report should be cited as: 

Carey, D. A.; Bellagamba Fucile, E. 2015. Data Summary Report of the New London Disposal 

Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014. U.S. 

Army Corps of Engineers, New England District, Concord, MA, 45 pp. 

Note on units of this report: As a scientific data summary, information and data are presented in the metric 

system. However, given the prevalence of English units in the dredging industry of the United States, 

conversions to English units are provided for general information in Section 1. A table of common conversions 

can be found in Appendix A. 
i 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

TABLE OF CONTENTS 

Page 

1.0 INTRODUCTION .......................................................................................................... 1

1.1 Overview of the DAMOS Program ................................................................................ 1

1.2 Overview of EPA’s Preparation of an SEIS for ELIS .................................................... 2

1.3 Introduction to the New London Disposal Site, Historic Niantic Bay Disposal 

Site, and the General Survey Area .................................................................................. 2

1.4 Previous NLDS Monitoring Surveys .............................................................................. 2

1.5 Recent Dredged Material Disposal Activity at NLDS .................................................... 3

1.6 2014 Survey Objectives .................................................................................................. 3

2.0 METHODS ..................................................................................................................... 5

2.1 Navigation and On-Board Data Acquisition ................................................................... 5

2.2 Sediment-Profile and Plan-View Imaging Survey .......................................................... 5

2.2.1 Sediment-Profile Imaging ........................................................................................... 5

2.2.2 Plan-View Imaging ..................................................................................................... 6

2.2.3 SPI and PV Survey Planning ...................................................................................... 7

2.2.4 SPI and PV Data Collection ........................................................................................ 7

2.2.5 SPI and PV Data Analysis .......................................................................................... 8

2.3 NLDS Substrata Characteristics ..................................................................................... 9

3.0 RESULTS ..................................................................................................................... 19

3.1 Sediment-Profile and Plan-View Imaging .................................................................... 19

3.1.1 Eastern Reference Areas (NE-REF, and NLON-REF) ............................................. 19

3.1.2 New London Disposal Site Stations ......................................................................... 20

3.1.3 Northern and Southern Transect Stations, Including the Central Reference 

Areas (NLON-ALT, and WREF) ............................................................................. 20

3.1.4 Niantic Bay Disposal Site Stations ........................................................................... 21

4.0 SUMMARY .................................................................................................................. 39

5.0 REFERENCES ............................................................................................................. 44

6.0 DATA TRANSMITTAL .............................................................................................. 45

 
ii 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

APPENDICES 

A Table of Common Conversions 

B NLDS/NBDS 2014 Survey Actual SPI/PV Replicate Locations 

C Sediment-Profile and Plan-View Image Analysis Results for NLDS/NBDS Survey, 

September 2014 

D Grain Size Scale for Sediments 

 
iii 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

LIST OF TABLES 

Page 

Table 2-1. NLDS Target SPI/PV Station IDs/Locations ........................................................ 10

Table 2-2. Substrata Habitat Types ........................................................................................ 13

Table 3-1. Summary of Substratum and Grain Size Major Mode (averaged across 

replicates) .............................................................................................................. 22

Table 4-1. Cross-walk of Substrata to LISS Habitats (Auster et al. 2009) ............................ 40
iv 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

LIST OF FIGURES 

Page 

Figure 1-1. Location of NLDS and NBDS ................................................................................ 4

Figure 2-1. Schematic diagram of the SPI/PV camera deployment ........................................ 14

Figure 2-3. Actual SPI/PV station locations and names at NBDS and the western 

section of the transects .......................................................................................... 16

Figure 2-4. Actual SPI/PV station locations and names at NLDS, the eastern section of 

the transects, and the central reference areas ........................................................ 17

Figure 2-5. Actual SPI/PV station locations at the eastern-most reference areas ................... 18

Figure 3-1. Sediment grain size major mode (phi units) at the eastern-most reference 

areas ...................................................................................................................... 24

Figure 3-2. Substrata characteristics at the eastern-most reference areas ............................... 25

Figure 3-3. Camera penetration depths at the eastern-most reference areas ........................... 26

Figure 3-4. Successional stage at the eastern-most reference areas ........................................ 27

Figure 3-5. Apparent Redox Potential Discontinuity (aRPD) at the eastern-most 

reference areas ...................................................................................................... 28

Figure 3-6. Sediment grain size major mode (phi units) within NLDS, the eastern 

transect stations, and the central reference areas .................................................. 29

Figure 3-7. Substrata characteristics within NLDS, the eastern transect stations, and 

the central reference areas ..................................................................................... 30

Figure 3-8. Camera penetration depths within NLDS, the eastern transect stations, and 

the central reference areas ..................................................................................... 31

Figure 3-9. Successional stage within NLDS, the eastern transect stations, and the 

central reference areas ........................................................................................... 32

Figure 3-10. Apparent Redox Potential Discontinuity (aRPD) within NLDS, the eastern 

transect stations, and the central reference areas .................................................. 33

Figure 3-11. Sediment grain size major mode (phi units) at stations within NBDS and 

the western transect stations.................................................................................. 34

Figure 3-12. Substrata characteristics at stations within NBDS and the western transect 

stations .................................................................................................................. 35
v 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Figure 3-13. Camera penetration depths at stations within NBDS and the western 

transect stations ..................................................................................................... 36

Figure 3-14. Apparent Redox Potential Discontinuity (aRPD) at stations within NBDS 

and the western transect stations ........................................................................... 37

Figure 3-15. Successional stage at stations within NBDS and the western transect 

stations areas ......................................................................................................... 38

Figure 4-1. Representative images from western part of the study area ................................. 41

Figure 4-2. Representative images from eastern part of the study area ................................... 42

Figure 4-3. Representative images from eastern-most reference areas ................................... 43

 
vi 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

LIST OF ACRONYMS 

aRPD apparent redox potential discontinuity 

CAD confined aquatic disposal 

CLDS Central Long Island Sound 

CSDS Cornfield Shoals 

DAMOS Disposal Area Monitoring System 

DGPS differential global positioning system 

ELIS Eastern Long Island Sound 

EPA Environmental Protection Agency 

GIS graphic information system 

GPS global positioning system 

JPEG Joint Photographic Experts Group 

NBDS Niantic Bay Disposal Site 

NLDS New London Disposal Site 

NAE New England District 

NEF Nikon Electronic Format 

ODMDS Ocean Dredged Material Disposal Sites 

PV plan-view 

RGB red green blue (file format) 

SBAS satellite-based differential corrections 

SEIS Supplemental Environmental Impact Statement 

SHP shapefile or geospatial data file 

SOP Standard Operating Procedures 

SPI sediment-profile imaging 

TIF tagged image file 

USACE U.S. Army Corps of Engineers 

USCG U.S. Coast Guard 

WLDS Western Long Island Sound 
Page 1 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

1.0 INTRODUCTION 

A sediment-profile (SPI) and plan-view (PV) imaging survey was conducted at the New London 

Disposal Site (NLDS) and within an area extending west of NLDS to, and including, the historic 

Niantic Bay Disposal Site (NBDS). This SPI/PV survey took place in September 2014 as part of 

the U.S. Army Corps of Engineers (USACE) New England District (NAE) Disposal Area 

Monitoring System (DAMOS) Program. DAMOS is a comprehensive monitoring and 

management program designed and conducted to address environmental concerns surrounding 

the placement of dredged material at aquatic disposal sites throughout the New England region. 

An introduction to the DAMOS Program, NLDS, and NBDS, including brief descriptions of 

previous dredged material disposal and site monitoring activities, is provided below. 

1.1 Overview of the DAMOS Program 

The DAMOS Program features a tiered management protocol designed to ensure that any 

potential adverse environmental impacts associated with dredged material disposal are promptly 

identified and addressed (Germano et al. 1994). For over 35 years, the DAMOS Program has 

collected and evaluated disposal site data throughout New England. Based on these data, 

patterns of physical, chemical, and biological responses of seafloor environments to dredged 

material disposal activity have been documented (Fredette and French 2004). 

DAMOS monitoring surveys fall into two general categories: confirmatory studies and focused 

studies. Confirmatory studies are designed to test hypotheses related to expected physical and 

ecological response patterns following placement of dredged material on the seafloor at 

established, active disposal sites. The data collected and evaluated during these studies provide 

answers to strategic management questions in determining the next step in the disposal site 

management process. Focused studies are periodically undertaken within the DAMOS Program 

to evaluate inactive or historical disposal sites and contribute to the development of dredged 

material placement and capping techniques. The resulting information from DAMOS surveys is 

used to guide the management of disposal activities at existing sites, plan for use of future sites, 

and evaluate the long term status of historic sites. The 2014 NLDS/NBDS investigation was a 

focused study designed as a reconnaissance survey in support of the Environmental Protection 

Agency’s (EPA) Supplemental Environmental Impact Statement (SEIS) for designating one or 

more regional dredged material disposal sites in Eastern Long Island Sound (ELIS). 

Two primary goals of DAMOS confirmatory monitoring surveys are to document the physical 

location and stability of dredged material placed into the aquatic environment and to evaluate the 

biological recovery of the benthic community following placement of dredged material. Several 

survey techniques are employed in order to characterize these responses to dredged material 

placement. Sequential acoustic monitoring surveys (including bathymetric, acoustic backscatter, 

and side-scan sonar data collection) are performed to characterize the height and spread of 

discrete dredged material deposits or mounds created at open water sites as well as the 

accumulation/consolidation of dredged material into confined aquatic disposal (CAD) cells. 

Sediment-profile imaging (SPI) and plan-view underwater camera photography, referred to as 

plan-view (PV) imaging, surveys are performed to provide further physical characterization of 

the material and to support evaluation of seafloor (benthic) habitat conditions and recovery over 
Page 2 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

time. Each type of data collection activity is conducted periodically at disposal sites, and the 

conditions found after a defined period of disposal activity are compared with the long-term data 

set at a specific site to determine the next step in the disposal site management process (Germano 

et al. 1994). Focused DAMOS monitoring surveys may also feature additional types of data 

collection activities as deemed appropriate to achieve specific survey objectives, such as subbottom profiling, towed video, sediment coring, or grab sampling. 

1.2 Overview of EPA’s Preparation of an SEIS for ELIS 

Currently there are four dredged material disposal sites in Long Island Sound: Western Long 

Island Sound (WLDS), Central Long Island Sound (CLDS), Cornfield Shoals (CSDS), and New 

London (NLDS). WLDS and CLDS were designated for long-term use by the Environmental 

Protection Agency (EPA) as Ocean Dredged Material Disposal Sites (ODMDSs) on June 5, 

2005. CSDS and NLDS sites were selected by USACE for short-term use and are due to close 

on December 16, 2016. As these two eastern sites are slated to close, the EPA posted a Notice of 

Intent on 4 October 2012 to prepare a Supplemental Environmental Impact Statement (SEIS) to 

evaluate the potential designation of one or more new ODMDSs to serve the eastern Long Island 

Sound region. 

1.3 Introduction to the New London Disposal Site, Historic Niantic Bay Disposal Site, 

and the General Survey Area 

NLDS is an active open-water dredged material disposal site located 5.4 km (3.1 nmi) south of 

Eastern Point, Groton, Connecticut (Figure 1-1) centered at 41o16.306 ́ N, 72o 04.571 ́ W (NAD 

83). Water depths range from 13.4 m (43 ft) to 24.3 m (79 ft) at its deepest point (AECOM 

2009). 

NBDS is an inactive historical disposal site that has not been used since likely 1972 (per notes 

from 1990 from Dr. Thomas Fredette, former DAMOS Program Manager). The center of the 

site is located approximately 2.6 km (1.4 nmi) southeast of Black Point, Niantic, Connecticut, 

and is being examined as a potential location for disposal site alternatives (Figure 1-1). 

The area surveyed between these two disposal sites includes a wide range of depths and zones of 

apparent active sediment transport. The SEIS is considering sites deeper than 18 m in the 

vicinity of major shipping corridors and lanes and may consider sites shallower than 18 m that 

are more remote from transportation corridors. The areas surveyed were selected to represent 

water depths at, or deeper than, the water depths of NLDS. 

1.4 Previous NLDS Monitoring Surveys 

The most recent survey at NLDS was conducted in July/August 2007 (AECOM 2009). Historic 

and previous dredged material disposal activity and monitoring events are summarized in 

AECOM (2009). 
Page 3 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

1.5 Recent Dredged Material Disposal Activity at NLDS 

Since the July/August 2007 survey approximately 20,000 cy (15,290 m3) of dredged material has 

been disposed of at NLDS. 

1.6 2014 Survey Objectives 

The objective of this survey was to use SPI/PV imaging to define the physical characteristics of 

surficial sediment and to assess the benthic community status of selected areas within NLDS and 

over an area extending 7 km west up to and including the historic NBDS. 
Page 4 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Surv

Figure 1-1. Location of NLDS and NBDS

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

72°5'0"W

72°5'0"W

72°6'0"W

72°6'0"W

72°7'0"W

72°7'0"W

72°8'0"W

72°8'0"W

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°19'0"N41°18'0"N41°17'0"N41°16'0"N

41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)

New London

Niantic

5

.

3

8

k

m

Eastern Point

CT

File: NLDS_2014_Overview

0 

1

New London Disposal Site (NLDS) Niantic Bay Disposal Site (NBDS)

NY

NLDS

NBDS

2.9 km

Black Point
Page 5 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

2.0 METHODS 

The September 2014 survey at NLDS, NBDS and the area between the two sites was conducted 

by a team of investigators from DAMOSVision (CR Environmental and Germano & Associates) 

aboard the 45-foot F/V Florence. The SPI/PV survey was conducted on 16-17 September 2014. 

An overview of the methods used to collect, process, and analyze the survey data is provided 

below. Detailed Standard Operating Procedures (SOPs) for data collection and processing are 

available in Carey et al. (2013). 

2.1 Navigation and On-Board Data Acquisition 

Navigation for the survey was accomplished using a Trimble AG132 Differential Global 

Positioning System (DGPS) capable of receiving satellite-based differential corrections (SBAS) 

and U.S. Coast Guard (USCG) Beacon corrections. The DGPS system was interfaced to a laptop 

computer running HYPACK® hydrographic survey software. 

The focus was to accurately occupy pre-established SPI survey target locations. HYPACK® 

continually recorded vessel position and DGPS satellite quality and provided a steering display 

for the vessel captain to navigate to the pre-established targets. 

Station target locations were entered into HYPACK® and viewed with a heads up display by the 

ship’s captain. When the vessel approached the center of the target location, the winch operator 

began the process of lowering the camera to the seafloor. The camera was lifted over the 

starboard side using a Pullmaster winch and boom, and then transferred to a stern gallows frame 

and trawl winch. The trawl winch lowered the camera to the seafloor. When the winch wire 

went slack, the deck hand signaled the winch operator and navigator to stop the winch and 

electronically record the vessel’s position. Each replicate camera position was electronically 

recorded and linked to the SPI log by station number and replicate with a time stamp and 

position. 

2.2 Sediment-Profile and Plan-View Imaging Survey 

Sediment-profile imaging (SPI) and plan-view (PV) imaging are monitoring techniques used to 

provide data on the physical characteristics of the seafloor and the status of the benthic biological 

community. 

2.2.1 Sediment-Profile Imaging 

Sediment-profile imaging (SPI) involves deploying an underwater camera system to photograph 

a cross section of the sediment-water interface. In the 2014 survey at NLDS/NBDS, highresolution SPI images were acquired using a Nikon® D7100 digital single-lens reflex camera 

mounted inside an Ocean Imaging® Model 3731 pressure housing system. The pressure housing 

sat atop a wedge-shaped prism with a front faceplate and a back mirror. The mirror was 

mounted at a 45° angle to reflect the profile of the sediment-water interface. As the prism 

penetrated the seafloor, a trigger activated a time-delay circuit that fired an internal strobe to 

obtain a cross-sectional image of the upper 15–20 cm of the sediment column (Figure 2-1). 
Page 6 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

The camera remained on the seafloor for approximately 20 seconds to ensure that a successful 

image had been obtained. Details of the camera settings for each digital image are available in 

the associated parameters file embedded in each electronic image file. For this survey, the ISOequivalent was set at 640, shutter speed was 1/250, f-stop was f9, and storage was in compressed 

raw Nikon Electronic Format (NEF) files (approximately 20 MB each). Electronic files were 

converted to high-resolution JPEG (8-bit) format files (3264 × 4928 pixels) using Nikon 

Capture® NX2 software (Version 2.2.7). 

Test exposures of the Kodak® Color Separation Guide (Publication No. Q-13) were made on 

deck at the beginning and end of the survey to verify that all internal electronic systems were 

working to design specifications and to provide a color standard against which final images 

could be checked for proper color balance. After deployment of the camera at each station, the 

frame counter was checked to ensure that the requisite number of replicates had been obtained. 

In addition, a prism penetration depth indicator on the camera frame was checked to verify that 

the optical prism had actually penetrated the bottom to a sufficient depth. If images were missed 

or the penetration depth was insufficient, the camera frame stop collars were adjusted and/or 

weights were added or removed, and additional replicate images were taken. Changes in prism 

weight amounts, the presence or absence of mud doors, and frame stop collar positions were 

recorded for each replicate image. 

Each image was assigned a unique time stamp in the digital file attributes by the camera’s data 

logger and cross-checked with the time stamp in the navigational system’s computer data file. In 

addition, the field crew kept redundant written sample logs. Images were downloaded 

periodically to verify successful sample acquisition and/or to assess what type of 

sediment/depositional layer was present at a particular station. Digital image files were renamed 

with the appropriate station names immediately after downloading as a further quality assurance 

step. 

2.2.2 Plan-View Imaging 

An Ocean Imaging® Model DSC16000 plan-view underwater camera (PV) system with two 

Ocean Imaging® Model 400-37 Deep Sea Scaling lasers mounted to the DSC16000 was 

attached to the sediment-profile camera frame and used to collect plan-view photographs of the 

seafloor surface; both SPI and PV images were collected during each “drop” of the system. The 

PV system consisted of a Nikon D-7000 encased in an aluminum housing, a 24 VDC 

autonomous power pack, a 500 W strobe, and a bounce trigger. A weight was attached to the 

bounce trigger with a stainless steel cable so that the weight hung below the camera frame; the 

scaling lasers projected two red dots that are separated by a constant distance (26 cm) regardless 

of the field-of-view of the PV system, which can be varied by increasing or decreasing the length 

of the trigger wire. As the camera apparatus was lowered to the seafloor, the weight attached to 

the bounce trigger contacted the seafloor prior to the camera frame hitting the bottom and 

triggered the PV camera (Figure 2-1). Details of the camera settings for each digital image are 

available in the associated parameters file embedded in each electronic image file; for this 

survey, the ISO-equivalent was set at 640 on the first survey day and then changed to 400 on the 

second survey day due to overexposure because of shell hash. The additional camera settings 

used were as follows: shutter speed 1/20, f14, white balance set to flash, color mode set to 
Page 7 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Adobe RGB, sharpening set to none, noise reduction off, and storage in compressed raw NEF 

files (approximately 20 MB each). Electronic files were converted to high-resolution JPEG (8-

bit) format files (3264 × 4928 pixels) using Nikon Capture® NX2 software. 

Prior to field operations, the internal clock in the digital PV system was synchronized with the 

GPS navigation system and the SPI camera. Each PV image acquired was assigned a time stamp 

in the digital file and redundant notations in the field and navigation logs. Throughout the 

survey, PV images were downloaded at the same time as the SPI images after collection and 

evaluated for successful image acquisition and image clarity. 

The ability of the PV system to collect usable images was dependent on the clarity of the water 

column. Water conditions at NLDS allowed a trigger wire length of 45 to 53 cm, resulting in an 

area of bottom visualization approximately 60 cm × 40 cm in size. 

2.2.3 SPI and PV Survey Planning 

For the NLDS/NBDS survey, a total of 60 SPI/PV stations were planned; 6 stations within 

NLDS, 11 stations within NBDS, 27 transect stations in the area between the two sites, and 4 

stations in each of four reference areas (Figure 2-2). 

Survey planning included stations at which prior EPA monitoring was performed. All 6 of the 

NLDS stations were original EPA stations; 8 of the 11 NBDS stations were original EPA stations 

and 12 of the 26 transect stations were also originally EPA stations. The reference stations and 

the newly added stations at NBDS and the transect area were chosen by consultation with EPA, 

the DAMOS Program Manager, Steve Wolf and senior scientist Drew Carey of DAMOSVision 

(Figures 2-3, 2-4, and 2-5). 

The eastern reference stations (NLON-REF and E-REF) and WREF stations were randomly 

located within standard reference areas utilized by DAMOS (AECOM 2009). NLON-ALT 

stations were randomly selected within a reference area chosen as a potential future reference 

area. The northern and southern transects were selected to provide a profile of conditions 

between the two disposal sites (Figure 2-2). 

Table 2-1 provides the original EPA Site Station ID numbers paired with the 2014 survey’s 

Station ID numbers and target locations. 

2.2.4 SPI and PV Data Collection 

The SPI/PV survey was conducted at NLDS/NBDS on 16-17 September 2014 aboard the F/V 

Florence. At each station, the vessel was positioned at the target coordinates and the camera was 

deployed within a defined station tolerance of 10 m. Four replicate SPI and PV images were 

collected at each of the stations (Figures 2-3, 2-4, and 2-5; Appendix B). The three replicates 

with the best quality images from each station were chosen for analysis (Appendix C). 

The DGPS described above was interfaced to HYPACK® software via laptop serial ports to 

provide a method to locate and record target sampling locations. Throughout the survey, the 

HYPACK® data acquisition system received DGPS data. The incoming data stream was 
Page 8 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

digitally integrated and stored on the PC’s hard drive. Actual SPI/PV sampling locations were 

recorded as target files using this system. 

2.2.5 SPI and PV Data Analysis 

Computer-aided analysis of the resulting images provided a set of standard measurements to 

allow comparisons between different locations and different surveys. The DAMOS Program has 

successfully used this technique for over 30 years to map the distribution of disposed dredged 

material and to monitor benthic recolonization at disposal sites. 

Following completion of data collection, the digital images were analyzed using Adobe 

Photoshop® CS 5 Version 12.1. Images were first adjusted in Adobe Photoshop® to expand the 

available pixels to their maximum light and dark threshold range. Linear and areal 

measurements were recorded as number of pixels and converted to scientific units using the 

Kodak® Color Separation Guide for measurement calibration. Detailed results of all SPI and PV 

image analyses are presented in Appendix C. 

2.2.5.1 SPI Data Analysis 

Analysis of each SPI image was performed to provide measurement of the following standard set 

of parameters: 

Sediment Type–The sediment grain size major mode and range were estimated visually from the 

images using a grain size comparator at a similar scale. Results were reported using the phi 

scale. Conversion to other grain size scales is provided in Appendix D. The presence and 

thickness of disposed dredged material were also assessed by inspection of the images. 

Penetration Depth–The depth to which the camera penetrated into the seafloor was measured to 

provide an indication of the sediment density or bearing capacity. The penetration depth can 

range from a minimum of 0 cm (i.e., no penetration on hard substrata) to a maximum of 20 cm 

(full penetration on very soft substrata). 

Surface Boundary Roughness–Surface boundary roughness is a measure of the vertical relief of 

features at the sediment-water interface in the sediment-profile image. Surface boundary 

roughness was determined by measuring the vertical distance between the highest and lowest 

points of the sediment-water interface. The surface boundary roughness (sediment surface relief) 

measured over the width of sediment-profile images typically ranges from 0 to 4 cm, and may be 

related to physical structures (e.g., ripples, rip-up structures, mud clasts) or biogenic features 

(e.g., burrow openings, fecal mounds, foraging depressions). Biogenic roughness typically 

changes seasonally and is related to the interaction of bottom turbulence and bioturbational 

activities. 

Apparent Redox Potential Discontinuity (aRPD) Depth–The aRPD depth provides a measure of 

the integrated time history of the balance between near-surface oxygen conditions and biological 

reworking of sediments. Sediment particles exposed to oxygenated waters oxidize and lighten in 

color to brown or light gray. As the particles are buried or moved down by biological activity, 

they are exposed to reduced oxygen concentrations in subsurface pore waters and their oxic 
Page 9 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

coating slowly reduces, changing color to dark gray or black. When biological activity is high, 

the aRPD depth increases; when it is low or absent, the aRPD depth decreases. The aRPD depth 

was measured by assessing color and reflectance boundaries within the images. 

Infaunal Successional Stage–Infaunal successional stage is a measure of the biological 

community inhabiting the seafloor. Current theory holds that organism-sediment interactions in 

fine-grained sediments follow a predictable sequence of development after a major disturbance 

(such as dredged material disposal), and this sequence has been divided subjectively into three 

stages (Rhoads and Germano 1982, 1986). Successional stage was assigned by assessing which 

types of species or organism-related activities were apparent in the images. 

Additional components of the SPI analysis included calculation of means and ranges for the 

parameters listed above and mapping of means of replicate values from each station. Station 

means were calculated from three replicates from each station and used in statistical analysis. 

2.2.5.2 PV Data Analysis 

The PV images provided a much larger field-of-view than the SPI images and provided valuable 

information about the landscape ecology and sediment topography in the area where the pinpoint 

“optical core” of the sediment profile was taken. Unusual surface sediment layers, textures, or 

structures detected in any of the sediment-profile images can be interpreted in light of the larger 

context of surface sediment features; i.e., is a surface layer or topographic feature a regularly 

occurring feature and typical of the bottom in this general vicinity or just an isolated anomaly? 

The scale information provided by the underwater lasers allows for accurate density counts 

(number per square meter) of attached epifaunal colonies, sediment burrow openings, or larger 

macrofauna or fish which may have been missed in the sediment-profile cross section. 

Information on sediment transport dynamics and bedform wavelength were also available from 

PV image analysis. Analysts calculated the image size and field-of-view and noted sediment 

type; recorded the presence of bedforms, burrows, tubes, tracks, trails, epifauna, mud clasts, and 

debris; and included descriptive comments (Appendix C). 

2.3 NLDS Substrata Characteristics 

In order to provide an integrated characterization of the seafloor substrata in the vicinity of the 

New London Disposal Site and Niantic Bay Disposal Site the results of SPI and PV imagery was 

used to define five broad habitat types (Table 2-2). 

 
Page 10 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Table 2-1. 

NLDS Target SPI/PV Station IDs/Locations 

LOCATION STATION ID Original EPA 

Site ID EASTING1 NORTHING1 LATITUDE2

 LONGITUDE2

NEW LONDON DISPOSAL SITE LOCATIONS 

New London NLDS 1 NL015 360852 201668 41° 16.500' 72° 4.860' 

New London NLDS 2 NL014 360686 201444 41° 16.380' 72° 4.980' 

New London NLDS 3 NLR014 360856 201112 41° 16.200' 72° 4.860' 

New London NLDS 4 NL013 360522 200888 41° 16.080' 72° 5.100' 

New London NLDS 5 NL011 361442 201117 41° 16.200' 72° 4.440' 

New London NLDS 6 NLP009 361446 200673 41° 15.960' 72° 4.440' 

NIANTIC BAY DISPOSAL SITE LOCATIONS

Niantic NBDS 1 NTP017 352401 199941 41° 15.600' 72° 10.920' 

Niantic NBDS 2 NTP018 352564 200609 41° 15.960' 72° 10.800' 

Niantic NBDS 3 NTP018 352143 200828 41° 16.080' 72° 11.100' 

Niantic NBDS 4 NTP023 351729 200159 41° 15.720' 72° 11.400' 

Niantic NBDS 5 NTP025 352228 200717 41° 16.020' 72° 11.040' 

Niantic NBDS 6 NTR001 351479 199824 41° 15.540' 72° 11.580' 

Niantic NBDS 7 NTR004 351721 201269 41° 16.320' 72° 11.400' 

Niantic NBDS 8 NTR018 353317 200725 41° 16.020' 72° 10.260' 

New Niantic NBDS 9 - 353104 201281 41° 16.321' 72° 10.410' 

New Niantic NBDS 10 - 352918 199856 41° 15.552' 72° 10.550' 

New Niantic NBDS 11 - 351413 200759 41° 16.045' 72° 11.623' 

EPA TRANSECT STATIONS

EPA Transect 

Reference EPA-P006 Refp006 357344 200086 41° 15.660' 72° 7.380' 

EPA Transect 

Reference EPA-P008 Refp008 358845 201097 41° 16.200' 72° 6.300' 

EPA Transect 

Reference EPA-P010 Refp010 358509 201206 41° 16.260' 72° 6.540' 

EPA Transect 

Reference EPA-P020 Refp020 353569 200615 41° 15.960' 72° 10.080' 

EPA Transect 

Reference EPA-P021 Refp021 354323 200731 41° 16.020' 72° 9.540' 

EPA Transect 

Reference EPA-P023 Refp023 358760 201207 41° 16.260' 72° 6.360' 

EPA Transect 

Reference EPA-P024 Refp024 358684 200207 41° 15.720' 72° 6.420' 

EPA Transect 

Reference EPA-P025 Refp025 357344 200086 41° 15.660' 72° 7.380' 

EPA Transect 

Reference EPA-P026 Refp026 357176 200085 41° 15.660' 72° 7.500' 
Page 11 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

LOCATION STATION ID Original EPA 

Site ID EASTING1 NORTHING1 LATITUDE2

 LONGITUDE2

EPA Transect 

Reference EPA-P027 Refp027 355669 199963 41° 15.600' 72° 8.580' 

EPA Transect 

Reference EPA-R007 Refr007 360100 201329 41° 16.320' 72° 5.400' 

EPA Transect 

Reference EPA-R024 Refr024 353658 199950 41° 15.600' 72° 10.020' 

NEW TRANSECT STATIONS

New Transect 

Reference NLT 1 - 360052 201892 41° 16.624' 72° 5.431' 

New Transect 

Reference NLT 2 - 359488 201848 41° 16.603' 72° 5.835' 

New Transect 

Reference NLT 3 - 356723 200925 41° 16.115' 72° 7.821' 

New Transect 

Reference NLT 4 - 356022 200792 41° 16.047' 72° 8.323' 

New Transect 

Reference NLT 5 - 355046 200683 41° 15.991' 72° 9.022' 

New Transect 

Reference NLT 6 - 354363 199922 41° 15.583' 72° 9.515' 

New Transect 

Reference NLT 7 - 354994 199941 41° 15.590' 72° 9.063' 

New Transect 

Reference NLT 8 - 356142 200002 41° 15.619' 72° 8.241' 

New Transect 

Reference NLT 9 - 357942 200125 41° 15.679' 72° 6.952' 

New Transect 

Reference NLT 10 - 359030 200225 41° 15.728' 72° 6.172' 

New Transect 

Reference NLT 11 - 359499 200342 41° 15.790' 72° 5.836' 

New Transect 

Reference NLT 12 - 360144 200354 41° 15.794' 72° 5.374' 

New Transect 

Reference NLT 13 - 359895 200635 41° 15.946' 72° 5.550' 

New Transect 

Reference NLT 14 - 360050 200972 41° 16.128' 72° 5.438' 

New Transect 

Reference NLT 15 - 359738 201161 41° 16.231' 72° 5.660' 

NLDS REFERENCE AREA STATIONS

NE-REF NE-REF 1 - 362910 201970 41° 16.654' 72° 3.384' 

NE-REF NE-REF 2 - 362832 202080 41° 16.714' 72° 3.440' 

NE-REF NE-REF 3 - 362939 202098 41° 16.724' 72° 3.363' 

NE-REF NE-REF 4 - 363006 202060 41° 16.703' 72° 3.315' 

NLON REF NLON REF 1 - 364970 201976 41° 16.649' 72° 1.909' 

NLON REF NLON REF 2 - 364787 201997 41° 16.661' 72° 2.040' 

NLON REF NLON REF 3 - 364889 201907 41° 16.612' 72° 1.967' 

NLON REF NLON REF 4 - 364893 202073 41° 16.702' 72° 1.963' 

NLON-ALT EPA NLON-ALT 1 - 357631 201201 41° 16.261' 72° 7.168' 
Page 12 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

LOCATION STATION ID Original EPA 

Site ID EASTING1 NORTHING1 LATITUDE2

 LONGITUDE2

NLON-ALT EPA NLON-ALT 2 - 357753 201102 41° 16.207' 72° 7.082' 

NLON-ALT EPA NLON-ALT 3 - 357860 201138 41° 16.226' 72° 7.005' 

NLON-ALT EPA NLON-ALT 4 - 357776 201262 41° 16.294' 72° 7.064' 

WREF WREF 1 - 359347 201065 41° 16.181' 72° 5.941' 

WREF WREF 2 - 359425 201108 41° 16.204' 72° 5.884' 

WREF WREF 3 - 359202 201132 41° 16.218' 72° 6.044' 

WREF WREF 4 - 359326 201227 41° 16.268' 72° 5.955' 

 

Notes 

1. Grid coordinates are Connecticut State Plane FIPS 0600 (NAD83), in meters 

2. Geographic coordinates are WGS84 degrees decimal minutes
Page 13 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Table 2-2. 

 

Substrata Habitat Types 

Substratum Characteristics Habitat Sediment transport 

Rock Hard bottom, boulders 

or large cobbles. 

Dominated by encrusting 

organisms: sponges, 

hydroids, algae, 

anemones and mobile 

epifauna 

Assumed to be eroded 

ridges of glacial till or 

drift. Some periodic 

settlement of fines as 

drape over rock 

surfaces. 

Shell Layer of disarticulated 

shells: common mussel 

(Mytilus), slipper shell 

(Crepidula), cockles 

(Cerastoderma) and 

clams (Ensis, Spisula, 

Mercenaria ). 

Surface layer of clean 

shells and pebbles on 

coarse to fine sand. 

Infauna in layer of coarse 

shell hash overlying fine 

sand and silt. Some 

encrusting organisms on 

pebbles. 

Assumed to be area of 

active strong near-bed 

currents moving shells 

(absence of epifaunal 

growth). 

Mobile sand Fine sand with 

bedforms, isolated shells 

and pebbles. 

Active infauna including 

acorn worms 

(Saccoglossus), deep 

burrowing polychaetes. 

Some resistant epifauna 

on shells or isolated 

pebbles. 

Assumed to be area of 

moderate near-bed 

currents sufficient to 

periodically move sand 

in bedload. 

Transitional Surface with shell layer 

and mud drape. 

Epifauna on shell layer 

and infaunal burrowing 

organisms. 

Episodic transport of 

shell alternating with 

deposition. 

Depositional Very fine sand or silt 

with no bedforms. 

Some isolated shells and 

pebbles 

Dominated by deep 

burrowing infauna and 

some encrusting 

organisms (hydroids, 

bryozoans, anemones) on 

hard surfaces 

Assumed to be low 

near-bed currents with 

very infrequent storm 

transport of surface 

sediment. 
Page 14 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 2-1. Schematic diagram of the SPI/PV camera deployment 
Page 15 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 2-2. Actual SPI/PV station locations at NLDS, NBDS, transects, and reference areas

!(

") !(

")

#* ") #*#*#*

")

") ") ") $+ $+ $+ ") $+ $+

$+ $+

$+

$+ $+ $+ ")

#*#*#*#*

#* 

#*#*#*

!(!(

!(

!(

")

") ")

") ")

") ") ")

") ") ") ")

") ")

")

")

")

")

WREF

NE-REF 

NLON-ALT EPA

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

72°5'0"W

72°5'0"W

72°6'0"W

72°6'0"W

72°7'0"W

72°7'0"W

72°8'0"W

72°8'0"W

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°19'0"N41°18'0"N41°17'0"N41°16'0"N41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)

New London

Niantic

5

.

3

8

k

m

Eastern Point

CT

File: NLDS_2014_Overview_SPI

0 

1

New London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area

NY

NLDS

NBDS

2.9 km

Black Point

Northern Transect

Southern Transect

SPI/PV Station Locations

$+ Niantic Bay EPA Station

$+ New Niantic Bay Station!( New London EPA Station

") EPA Transect Reference Station") New Transect Reference Station

#* Reference Area Station

Bartlett Reef
Page 16 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 2-3. Actual SPI/PV station locations and names at NBDS and the western section of the transects 

")

")

")

")

$+

$+

$+

$+ $+

$+ $+

$+

$+

$+

$+

")

") ") ") ")

NLT-6 NLT-7 NLT-8

NLT-5

NLT-4

NBDS-1

NBDS-6

NBDS-4

NBDS-7 NBDS-9

NBDS-3

NBDS-5

NBDS-2

NBDS-8

NBDS-10

NBDS-11

EPA-R024 EPA-P027

EPA-P021

EPA-P020

7

72

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°16'0"N

41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: NOS Multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

File Name: NLDS_2014_Popup_West_blue

New London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area

$+ Niantic Bay EPA Station$+ New Niantic Bay Station!( New London EPA Station

") EPA Transect Reference Station") New Transect Reference Station

#* Reference Area Station

SPI/PV Station Locations
Page 17 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 2-4. Actual SPI/PV station locations and names at NLDS, the eastern section of the transects, and the c

!(

!(

")

")

")

#*#* #*

#* #* #*

#* #* !(

!(

!(

!(

")

") ")

") ")

") ") ")

") ")

")

")

")

")

NLT-2 NLT-1

NLT-9

NLT-10

NLT-11 NLT-12

NLT-13

NLDS-4

NLDS-3

NLDS-6

NLDS-5

WREF-4

WREF-3

NLT-15

NLT-14

NLDS-2

NLDS-1

EPA-P025

EPA-P008

EPA-P023

EPA-P026

NLON-ALT3 EPA-R007

NLON-ALT4

WREF-1

WREF-2

EPA-P010

EPA-P006 EPA-P024

NLON-ALT2

NLON-ALT1

72°5'0"W

72°5'0"W

72°6'0"W

72°6'0"W

72°7'0"W

72°7'0"W

41°17'0"N41°16'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)

0 

0.25

New London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area

$+ Niantic Bay EPA Station$+ New Niantic Bay Station!( New London EPA Station

") EPA Transect Reference Station") New Transect Reference Station

#* Reference Area Station

SPI/PV Station Locations

File Name: NLDS_2014_Popup_East_blue
Page 18 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 2-5. Actual SPI/PV station locations at the eastern-most reference areas

#*

#*

#*

#*

#*

#* #*

#*

NE-REF1

NE-REF2

NE-REF3

NE-REF4

NLON-REF2

NLON-REF3

NLON-REF4

NLON-R

72°2'0"W

72°2'0"W

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

41°17'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)

0 

0.25

New London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area

$+ Niantic Bay EPA Station$+ New Niantic Bay Station!( New London EPA Station

") EPA Transect Reference Station") New Transect Reference Station

#* Reference Area Station

SPI/PV Station Locations

File Name: NLDS_2014_Popup_Refs_blue
Page 19 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

3.0 RESULTS 

3.1 Sediment-Profile and Plan-View Imaging 

The primary purpose of the SPI/PV survey at NLDS/NBDS was to characterize the physical 

features of the surface sediment throughout the study area and to assess the status of benthic 

recolonization within the disposal site. A total of 60 SPI/PV stations were occupied; 6 stations 

within NLDS, 11 stations within NBDS, 27 transect stations in the area between the two sites, 

and 4 stations in each of four reference areas (NLON-ALT, WREF, NE-REF, and NLON-REF). 

A station summary of some measured parameters can be found in Table 3-1 with a complete set 

of results in Appendix C. 

3.1.1 Eastern Reference Areas (NE-REF, and NLON-REF) 

Physical Sediment Characteristics 

The eastern reference areas were primarily very fine sand (4 to 3 phi) but some replicates had 

evidence of silt layers beneath the surface (Figure 3-1 and Appendix C). NE-REF had fine (3 to 

2 phi) and very fine sand with no evidence of sediment transport, which was classified as a 

depositional substratum (Figure 3-2). NLON-REF had very fine sand with evidence of sediment 

transport, which was classified as mobile sand substratum (fine sand with bedforms, isolated 

shells and pebbles; assumed to be area of moderate near-bed currents sufficient to periodically 

move sand in bedload). However, several replicates had silt (>4 phi) below the very fine sand 

and clearly had experienced periods of deposition (Appendix C). The difference between the 

reference areas was illustrated by the relative penetration depths of the camera (Figure 3-3; 

NLON-REF mean 5.3 cm and NE-REF mean of 9.1 cm). 

Biological Conditions 

The eastern reference areas had typical shallow water estuarine infaunal characteristics (burrows, 

bioturbation, and deep aRPDs) and numerous epifaunal scavenging organisms (Appendix C). 

Common infaunal deposit feeders in fine sand habitats of eastern Long Island Sound include 

numerous polychaetes and Saccoglossus kowalewskyi, an enteropneust that deposits a distinctive 

fecal coil on the surface. Saccoglossus is typically found in mobile sand habitats in eastern Long 

Island Sound and more quiescent habitats in the Gulf of Maine. Another typical infaunal 

organism, Chaetopterus variopedatus forms a thick parchment tube in the sediment and pumps 

water through the tube. Both Saccoglossus coils and Chaetopterus tubes were found at NLONREF but not at NE-REF (Appendix C). NE-REF had large burrow openings and polychaetes 

visible below the sediment-water interface. 

All stations at the eastern reference areas had at least one replicate with evidence of Stage 3 

equilibrium conditions (Saccoglossus coils are one type of such evidence, Figure 3-4). The mean 

aRPD for all stations at NLON-REF was 3.6 cm and for NE-REF, 4.6 cm (Figure 3-5). 
Page 20 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

3.1.2 New London Disposal Site Stations 

Physical Sediment Characteristics 

The NLDS stations were located in areas that received dredged material over many years and are 

typical of conditions seen there (AECOM 2009, Carey et al. 2013). The surface sediments 

consisted of fine to medium sand overlying silt (Figure 3-6). In one case, there was a large rock 

that prevented grain size assessment with SPI but the PV images clearly showed a surface layer 

of sand (Appendix C). The surface layer had clear evidence of sediment transport and lag 

deposits (shells and pebbles) but the shells were covered with a thin layer of silt (‘mud drape’). 

As a result, the substrate was classified as transitional (Figure 3-7). In this case, the presence of 

consolidated silt underneath a surface layer of fine to medium sand, shells and silt layers, 

indicated periodic sediment transport sufficient to move unconsolidated fine sand but not enough 

to move shells and silt. The camera penetration depth was a clear indicator of the presence of 

soft dredged material below the surface of fine sand; penetration depths ranged from 0 (rock) to 

18.8 cm (Figure 3-8). 

Biological Conditions 

The sediments at NLDS were heavily bioturbated with numerous burrows and evidence of 

subsurface feeding (Appendix C). The shell lag and pebbles had encrusting and attached 

epifauna, further evidence that the shells do not move frequently. All of the stations that could 

be measured had evidence of Stage 3 equilibrium conditions (feeding voids and burrows, Figure 

3-9). The mean aRPD for all stations at NLDS was 3.1 cm (Figure 3-10). 

3.1.3 Northern and Southern Transect Stations, Including the Central Reference Areas 

(NLON-ALT, and WREF) 

Physical Sediment Characteristics 

The northern and southern transects were selected to provide a profile of conditions between the 

two disposal sites. As such, the physical conditions along the transects covered a wide range. 

Both transects crossed north-south oriented boulder ridges and a southeast-northwest oriented 

sand ridge (Figure 2-2). One of the ridges is an extension of Bartlett Reef and these ridges are 

likely part of a complex of glaciolacustrine systems in Long Island Sound representing deltaic 

and ice-marginal deposits (Figure 2-2 and Stone et al. 2005). Between the ridges the seafloor 

deepens and forms small erosional basins. The two central reference areas had four random 

stations each and conditions were quite similar within them. WREF has been used routinely for 

assessment of NLDS disposal activities, NLON-ALT has not. WREF had consistent shelly fine 

sand over silt (3 to 2/ >4 phi) while NLON-ALT was primarily shelly fine sand with some 

underlying silt and a visible mud drape over the shells (Figure 3-6). WREF had clear evidence 

of sediment transport features and was classified as mobile sand while NLON-ALT appeared to 

be more transitional with mud deposits and epifauna (Figure 3-7). These results suggested that 

the two reference areas are similar to NLDS: experiencing periodic bottom stress capable of 

moving sand or shell particles, but also periods of quiescent conditions that allow deposition of 
Page 21 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

silt. The camera penetration depth measurements indicated that WREF was softer than NLONALT with a mean penetration depth of 7.6 cm compared to 4.8 cm (Figure 3-8). 

The northern transect included stations previously sampled by EPA and newly selected stations 

to provide a characterization of a corridor connecting the central reference stations to the two 

disposal sites (Figure 2-2). Station grain sizes ranged from fine sand to medium sand over silt, 

with several indeterminate stations due to hard bottom or shells (Figures 3-6 and 3-11). The 

southern transect stations were chosen to link the existing EPA stations to a corridor between the 

two disposal sites (Figure 2-2). Station grain sizes ranged from very fine sand to gravel over silt 

(Figures 3-6 and 3-11). The northern transect stations in the east (near NLDS) were all mobile 

sand or transitional substrata, consistent with the two reference areas (Figure 3-7). The northern 

transect stations in the west (near NBDS) were a mix of coarse shells on the margins of ridges; 

mobile sand and transitional in the deeper basin (Figure 3-12). The southern transect stations in 

the east were mobile sand or transitional up to a resistant hard ridge with rock and shells (Figure 

3-7). The southern transect stations in the west were rock and shells over another hard ridge and 

then transitional in the basin to rock on another hard ridge at the eastern edge of NBDS (Figure 

3-12). Camera penetration depths varied widely along the northern transect from 0 to 9.2 cm and 

along the southern transect from 0 to 10.9 cm (Figure 3-8 and 3-13). 

Biological Conditions 

The sediments at WREF and NLON-ALT were bioturbated with some evidence of subsurface 

feeding (Appendix C). The shell lag and pebbles had encrusting and attached epifauna, further 

evidence that the shells do not move frequently. All of the stations that could be measured had 

evidence of Stage 3 equilibrium conditions at WREF, and evidence of mostly Stage 2 at NLONALT (Figure 3-9). The mean aRPD for all stations at WREF was 3.6 cm and at NLON-ALT 

only one station had a measurable aRPD due to layers of shell on the surface (Figure 3-10). 

Along both transects the presence of shells (Mytilus and Crepidula) and rock surfaces provided 

substrata for many epifaunal organisms (sponges, anemones, bryozoans, hydroids, and 

barnacles). In the softer sediments within the basins, there was evidence of burrowing organisms 

and, in places, large numbers of Crepidula shells. The aRPD values in the northern transect 

ranged from 2.9 to 6.5 cm and in the southern transect ranged from 2.0 to 4.7 cm (Figures 3-10 

and 3-14). 

3.1.4 Niantic Bay Disposal Site Stations 

Physical Sediment Characteristics 

The NBDS stations were located in an area that had not received dredged material in many years; 

despite the history of the site, no dredged material was detected in the stations sampled. The 

southeast triangular portion of the site (Stations 1, 2, 6, 8 and 10) had a surface layer of coarse 

shells overlying fine and very fine sand (Figure 3-11). The presence of the shell layer appears to 

be a lag deposit overlying sand and was classified as shell substratum (Figure 3-12). In the 

northwest triangular portion of the site (Stations 3, 4, 5, 7, 9 and 11) the surface layer had fewer 

shells and fine sand (Figure 3-11). In this area the surface layer had clear evidence of sediment 
Page 22 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

transport; as a result, the substrate was classified as mobile sand (Figure 3-12). In both cases, 

there was evidence of active bedload transport sufficient to move unconsolidated fine sand and 

periodically enough to move shells (shells had some evidence of epifauna but appeared to be 

fairly clean). The camera penetration depth was a clear indicator of the relative distribution of 

compacted sand and shells; mean penetration depths were 5.1 cm in the southeast and 6.5 cm in 

the northwest (Figure 3-13). Stations 1 and 10 in the southeast had more fine sand and silt below 

the surface and deeper penetration; Station 5 had compacted sand and very limited penetration 

(Figure 3-13). 

Biological Conditions 

The mobile sand and shelly substrata had relatively little evidence of biological activity: some 

signs of bioturbation and epifaunal organisms on shells. These substrata are typically inhabited 

by highly mobile epifauna, and some infauna that are adapted to moving surface layers (but 

without fine sediment content there was little evidence of burrows or aRPDs). Only one 

replicate had evidence of Stage 3 (Station 4B); again a typical result in coarse sediments where 

Stage 2 evidence (shallow burrowing, lack of anoxic subsurface sediments) is most common 

(Figure 3-15). The aRPDs were indeterminate in six of the eleven stations; the mean aRPD was 

3.1 cm (Figure 3-14). 

Table 3-1. 

 

Summary of Substratum and Grain Size Major Mode (averaged across replicates) 

Location Station Substratum Grain Size Major Mode 

NLDS NLDS 1 Transitional 3 to 2/ >4 

NLDS 2 Transitional 3 to 2/ >4 

NLDS 3 Transitional 2 to 1/ >4 

NLDS 4 Transitional 3 to 2/ >4 

NLDS 5 Transitional 3 to 2/ >4 

NLDS 6 Transitional ind 

EPA P006 Shell 3 to 2/ >4 

EPA P008 Transitional 3 to 2/ >4 

EPA P010 Transitional 3 to 2/ >4 

EPA P020 Shell 3 to 2/ >4 

EPA P021 Mobile Sand 2 to 1/ >4 

EPA P023 Transitional 3 to 2/ >4 

EPA P024 Rock < 1 / >4 

EPA P025 Shell 1 to 0 

EPA P026 Shell 3 to 2/ >4 

EPA P027 Shell 1 to 0 

EPA R007 Mobile Sand 3 to 2 

EPA R024 Rock ind 

NBDS NBDS 1 Shell 2 to 1/ >4 

NBDS 2 Shell 2 to 1 
Page 23 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Location Station Substratum Grain Size Major Mode 

NBDS 3 Mobile Sand 3 to 2 

NBDS 4 Mobile Sand 3 to 2 

NBDS 5 Mobile Sand 3 to 2 

NBDS 6 Shell 3 to 2 

NBDS 7 Mobile Sand 3 to 2 

NBDS 8 Shell 3 to 2 

NBDS 9 Mobile Sand 3 to 2 

NBDS 10 Shell 3 to 2 

NBDS 11 Mobile Sand 3 to 2 

New Transect NLT 1 Transitional 3 to 2/ >4 

NLT 2 Mobile Sand 3 to 2/ >4 

NLT 3 Shell ind 

NLT 4 Shell ind 

NLT 5 Transitional 2 to 1/ >4 

NLT 6 Transitional 2 to 1/ >4 

NLT 7 Transitional 3 to 2 

NLT 8 Rock ind 

NLT 9 Shell 2 to 1/ >4 

NLT 10 Mobile Sand 1 to 2 

NLT 11 Mobile Sand 3 to 2/ >4 

NLT 12 Mobile Sand 3 to 2/ >4 

NLT 13 Mobile Sand 3 to 2/ >4 

NLT 14 Transitional 3 to 2/ >4 

NLT 15 Mobile Sand 3 to 2/ >4 

Reference Areas WREF 1 Mobile Sand 3 to 2/ >4 

WREF 2 Mobile Sand 3 to 2/ >4 

WREF 3 Mobile Sand 3 to 2/ >4 

WREF 4 Mobile Sand 3 to 2/ >4 

NLON ALT1 Transitional 3 to 2 

NLON ALT2 Transitional 3 to 2 

NLON ALT3 Transitional 3 to 2 

NLON ALT4 Transitional 3 to 2/ >4 

NLON REF1 Mobile Sand 4 to 3 

NLON REF2 Mobile Sand 4 to 3 

NLON REF3 Mobile Sand 4 to 3 

NLON REF4 Mobile Sand 4 to 3/ >4 

NE REF1 Depositional 3 to 2 

NE REF2 Depositional 4 to 3 

NE REF3 Depositional 4 to 3 

NE REF4 Depositional 4 to 3 
Page 24 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-1. Sediment grain size major mode (phi units) at the eastern-most reference areas

!<

!

!

!

!

! !

!

NE-REF1

NE-REF2

NLON-REF2

NLON-REF3

NE-REF3

NE-REF4

NLON

NLON-REF4

72°2'0"W

72°2'0"W

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

41°17'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_Refs_NLDS_GrainSize

Grain Size Major Mode (phi)

!<gravel over silt/clay (<-1 / >4)

! coarse sand (1 to 0)! medium sand (2 to 1)

!<medium sand over silt/clay (2 to 1 / >4)

! fine sand (3 to 2)

!<fine sand over silt/clay (3 to 2 / >4)

!<very fine sand over silt

! very fine sand (4 to 3)

indeterminate
Page 25 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-2. Substrata characteristics at the eastern-most reference areas

!!

!!

!!

!! !! !! !! !!

NE-REF1

NE-REF2

NLON-REF2

NLON-REF3

NE-REF3

NE-REF4

NLON

NLON-REF4

72°2'0"W

72°2'0"W

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

41°17'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic 

0 0

0.25

New London Disposal Site (NLDS) Reference Area 

File Name: NLDS_2014_SPI_REfs_NBDS_5x_spectrum_substrata

Background: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)

Substrata

!! Depositional!! Transitional!! Mobile Sand

û 

st 
Page 26 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-3. Camera penetration depths at the eastern-most reference areas

¶ ¶ ¶

¶ ¶

¶

¶

¶

NE-REF1

NE-REF2

NLON-REF2

NLON-REF3

NE-REF3

NE-REF4

NLON

NLON-REF4

72°4'0"W 72°3'0"W 72°2'0"W

41°17'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_Refs_Pen

Mean Camera Pen

¶ 0.0

¶ 2.5 - 4.9

¶ 5.0 - 9.9

¶ 10.0 - 14.9

¶15.0 - 20.4
Page 27 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-4. Successional stage at the eastern-most reference areas

NE-REF1

NE-REF2

NLON-REF2

NLON-REF3

NE-REF3

NE-REF4

NLON

NLON-REF4

72°2'0"W

72°2'0"W

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

41°17'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_Refs_SS

Succession

StagStagStagInde
Page 28 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-5. Apparent Redox Potential Discontinuity (aRPD) at the eastern-most reference areas

NE-REF1

NE-REF2

NLON-REF2

NLON-REF3

NE-REF3

NE-REF4

NLON

NLON-REF4

72°2'0"W

72°2'0"W

72°3'0"W

72°3'0"W

72°4'0"W

72°4'0"W

41°17'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_Refs_aRPD

Mean 
Page 29 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-6. Sediment grain size major mode (phi units) within NLDS, the eastern transect stations, and the ce

!<

!<

!

!<

!<!<!<!<! !<!< ! ! !<!<

!<

!<

!<!<

!<!

!<!<!<

!<!<

!<

!<

!

!<

NLT-1 NLT-2

NLT-9

NLT-10

NLT-11 NLT-12

NLT-13

NLDS-4

NLDS-3

NLDS-6NLDS-5

WREF-4

WREF-3

NLT-15

NLT-14

NLDS-2

NLDS-1

EPA-P025

EPA-P008

EPA-P023

EPA-P026

EPA-R007 NLON-ALT3

NLON-ALT4

WREF-1

WREF-2 EPA-P010

EPA-P006

EPA-P024

NLON-ALT2

NLON-ALT1

72°7'0"W 72°6'0"W 72°5'0"W 

41°17'0"41°16'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_East_NLDS_GrainSize

Grain Size Major Mode (phi)

!<gravel over silt/clay (<-1 / >4)

! coarse sand (1 to 0)! medium sand (2 to 1)

!<medium sand over silt/clay (2 to 1 / >4)

! fine sand (3 to 2)

!<fine sand over silt/clay (3 to 2 / >4)

!<very fine sand over s

! very fine sand (4 to 

indeterminate
Page 30 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-7. Substrata characteristics within NLDS, the eastern transect stations, and the central reference area

!!

!!

!!

!!

!! !!!! !! !! ! !! !!! !! !!

!!

!!

!!

!!

!! !!

û !!

st st st

!! !!

!!

!!

st

!!

NLT-1 NLT-2

NLT-9

NLT-10

NLT-11 NLT-12

NLT-13

NLDS-4

NLDS-3

NLDS-6NLDS-5

WREF-4

WREF-3

NLT-15

NLT-14

NLDS-2

NLDS-1

EPA-P025

EPA-P008

EPA-P023

EPA-P026

EPA-R007

NLON-ALT3

NLON-ALT4

WREF-1

WREF-2

EPA-P010

EPA-P006 EPA-P024

NLON-ALT2

NLON-ALT1

72°5'0"W

72°5'0"W

72°6'0"W

72°6'0"W

72°7'0"W

72°7'0"W

41°17'0"N41°16'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic 

Background: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)

0 0

0.25

New London Disposal Site (NLDS) Reference Area 

File Name: NLDS_2014_SPI_East_NBDS_5x_spectrum_substrata

Substrata

!! Depositional!! Transitional

!! Mobile 

û Rock

st Shell
Page 31 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-8. Camera penetration depths within NLDS, the eastern transect stations, and the central reference ar

¶

¶

¶

¶

¶

¶

¶

¶

¶

¶ ¶

¶

¶

¶

¶

¶

¶

¶

¶ ¶

¶

¶

¶

¶ ¶

¶

¶

¶

¶

¶

¶

NLT-1 NLT-2

NLT-9

NLT-10

NLT-11 NLT-12

NLT-13

NLDS-4

NLDS-3

NLDS-6

NLDS-5

WREF-4

WREF-3

NLT-15

NLT-14

NLDS-2

NLDS-1

EPA-P025

EPA-P008

EPA-P023

EPA-P026

EPA-R007 NLON-ALT3

NLON-ALT4

WREF-1

WREF-2 EPA-P010

EPA-P006

EPA-P024

NLON-ALT2

NLON-ALT1

72°5'0"W

72°5'0"W

72°6'0"W

72°6'0"W

72°7'0"W

72°7'0"W

41°17'0"N41°16'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_East_Pen

Mean Camera Pene

¶ 0.0

¶ 2.5 - 4.9

¶ 5.0 - 9.9

¶ 10.0 - 14.9

¶15.0 - 20.4
Page 32 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-9. Successional stage within NLDS, the eastern transect stations, and the central reference areas

NLT-1 NLT-2

NLT-9

NLT-10

NLT-11 NLT-12

NLT-13

NLDS-4

NLDS-3

NLDS-6

NLDS-5

WREF-4

WREF-3

NLT-15

NLT-14

NLDS-2

NLDS-1

EPA-P025

EPA-P008

EPA-P023

EPA-P026

EPA-R007

NLON-ALT3

NLON-ALT4

WREF-1

WREF-2

EPA-P010

EPA-P006

EPA-P024

NLON-ALT2

NLON-ALT1

72°7'0"W 72°6'0"W 72°5'0"W 

41°17'0"41°16'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_East_SS

Successio

StaStaStaInd
Page 33 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-10. Apparent Redox Potential Discontinuity (aRPD) within NLDS, the eastern transect stations, and th

areas

NLT-1 NLT-2

NLT-9

NLT-10

NLT-11 NLT-12

NLT-13

NLDS-4

NLDS-3

NLDS-6NLDS-5

WREF-4

WREF-3

NLT-15

NLT-14

NLDS-2

NLDS-1

EPA-P025

EPA-P008

EPA-P023

EPA-P026

EPA-R007 NLON-ALT3

NLON-ALT4

WREF-1

WREF-2 EPA-P010

EPA-P006

EPA-P024

NLON-ALT2

NLON-ALT1

72°7'0"W 72°6'0"W 72°5'0"W 

41°17'0"41°16'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014) 0 

0.25 

New London Disposal Site (NLDS) Reference Area

File Name: NLDS_2014_SPI_East_aRPD

Mean 
Page 34 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-11. Sediment grain size major mode (phi units) at stations within NBDS and the western transect stati

!<!< !< ! ! !

! !

! !

!

!

!<

!

! ! !<

NLT-6 NLT-7 NLT-8

NLT-5

NLT-4

NBDS-1

NBDS-6

NBDS-4

NBDS-7 NBDS-9

NBDS-3

NBDS-5

NBDS-2

NBDS-8

NBDS-10

NBDS-11

EPA-R024 EPA-P027

EPA-P020

EPA-P021

7

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°16'0"N

41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

File Name: NLDS_2014_SPI_West_NBDS_GrainSize

Grain Size Major Mode (phi)

!<gravel over silt/clay (<-1 / >4)

! coarse sand (1 to 0)! medium sand (2 to 1)

!<medium sand over silt/clay (2 to 1 / >4)

! fine sand (3 to 2)

!<fine sand over silt/clay (3 to 2 / >4)

!<very fine sand over silt

! very fine sand (4 to 3)

indeterminate

Niantic Bay Disposal Site (NBDS)

Depth (m)
Page 35 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-12. Substrata characteristics at stations within NBDS and the western transect stations

st ! !! ! st st st !!!! !!

!! !!

!!

st

st

st

û !! !! st û

NLT-6 NLT-7

NLT-8

NLT-5

NLT-4

NBDS-1

NBDS-6

NBDS-4

NBDS-7 NBDS-9

NBDS-3

NBDS-5

NBDS-2

NBDS-8

NBDS-10

NBDS-11

EPA-R024 EPA-P027

EPA-P020

EPA-P021

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°16'0"N41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic 

0 0

0.25

File Name: NLDS_2014_SPI_West_NBDS_5x_spectrum_substrata

Background: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)

Substrata

!! Depositional!! Transitional!! Mobile Sand

û R

st S

Niantic Bay Disposal Site (NBDS)
Page 36 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-13. Camera penetration depths at stations within NBDS and the western transect stations

¶ ¶

¶

¶

¶

¶

¶

¶

¶

¶ ¶

¶

¶

¶

¶

¶

¶ ¶

¶

¶

NLT-6 NLT-7 NLT-8

NLT-5

NLT-4

NBDS-1

NBDS-6

NBDS-4

NBDS-7 NBDS-9

NBDS-3

NBDS-5

NBDS-2

NBDS-8

NBDS-10

NBDS-11

EPA-R024 EPA-P027

EPA-P020

EPA-P021

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°16'0"N41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

File Name: NLDS_2014_SPI_West_Pen

Niantic Bay Disposal Site (NBDS)

Depth (m)

Mean Camera Pene

¶ 0.0

¶ 2.5 - 4.9

¶ 5.0 - 9.9

¶ 10.0 - 14.9

¶15.0 - 20.4
Page 37 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-14. Apparent Redox Potential Discontinuity (aRPD) at stations within NBDS and the western transec

NLT-6 NLT-7 NLT-8

NLT-5

NLT-4

NBDS-1

NBDS-6

NBDS-4

NBDS-7 NBDS-9

NBDS-3

NBDS-5

NBDS-2

NBDS-8

NBDS-10

NBDS-11

EPA-R024 EPA-P027

EPA-P020

EPA-P021

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°16'0"N41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 

0.25 

File Name: NLDS_2014_SPI_West_aRPD

Niantic Bay Disposal Site (NBDS)

Depth (m)

Mea
Page 38 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Sur

Figure 3-15. Successional stage at stations within NBDS and the western transect stations areas

NLT-6 NLT-7 NLT-8

NLT-5

NLT-4

NBDS-1 NBDS-6

NBDS-4

NBDS-7 NBDS-9

NBDS-3

NBDS-5 NBDS-2

NBDS-8

NBDS-10

NBDS-11

EPA-R024 EPA-P027

EPA-P020

EPA-P021

72

72°

72°9'0"W

72°9'0"W

72°10'0"W

72°10'0"W

72°11'0"W

72°11'0"W

72°12'0"W

72°12'0"W

41°16'0"N

41°15'0"N

Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter

Background: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014) 0 0

0.25 

File Name: NLDS

_

2014

_

SPI

_

West

_

SS

Niantic Bay Disposal Site (NBDS)

Depth (m)

Successiona

Stage Stage Stage Indete
Page 39 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

4.0 SUMMARY 

The SPI/PV survey obtained images of cross-sections of the sediment-water interface and planview images of the seafloor surface. The results included estimated grain-size information, 

evidence of sediment transport conditions, biological characteristics, and the effects of biological 

activity. SPI and PV can detect some conspicuous species but are primarily used to infer process 

from patterns of sedimentological and biological processes (Germano et al. 2011, Carey et al. 

2014). The observed textures and patterns in the seafloor surface and subsurface provided 

evidence of the recent history of physical and biological processes that is relevant to 

management decisions (i.e., dredged material placement). 

The SPI/PV survey characterized the physical characteristics of selected stations by measuring 

properties visible in SPI images (grain size major mode, penetration depth, boundary roughness, 

mud clasts), and observations from both SPI and PV images (sediment layers, sediment transport 

features). The biological assessment utilized the standard SPI biological assessment (Germano 

et al. 2011) to generate measured parameters (aRPD, feeding voids, methane, successional stage) 

and included additional observations from SPI and PV images on infauna, epifauna and traces of 

biological activity). Representative images for each reference area, transect, and disposal site 

illustrated the range of sediment conditions sampled during the survey (Figures 4-1, 4-2, 4-3). 

In order to provide an integrated characterization of the seafloor, the results of physical and 

biological characterization from SPI and PV imagery was used to define five broad habitat types 

(Table 2-2). Seafloor habitats can be defined for many different scales but for this study 

represented distinctive bottom types of substrata and associated organisms within eastern Long 

Island Sound. These were defined based on visual characteristics and are not intended to 

correlate one to one with national standards or Long Island Sound Study (LISS) habitat mapping 

schemes (Auster et al. 2009, Shumchenia et al. 2014). The purpose was to allow specific areas 

of eastern Long Island Sound to be related to bottom stress modeling results. However, the 

general types described had a one to many relationship to the LISS approach (Table 4-1). The 

results could be cross-walked to the Coastal and Marine Ecological Classification Standard 

(CMECS) with additional analysis, but the simple habitat types are sufficient to assess suitability 

of areas for potential disposal sites (FGDC 2012). 

The habitat types: rock and shells are expected to correlate with modeled or measured bottom 

stress values above the critical shear stress for transport of consolidated fine materials. The 

mobile sand habitat is expected to correlate with modeled or measured bottom stress values 

above the critical shear stress for bedload transport of sand particles. The transitional and 

depositional habitats are expected to correlate with modeled or measured bottom stress values 

below the value for transport of unconsolidated fine particles. Open water disposal sites are 

generally placed in habitats with relatively fine sediments below the wave base that experience 

transitional or depositional conditions. 
Page 40 of 45 

DAMOS Data Summary Report – New London Dispo

Sediment-Profile and Plan-View Imaging Surv

Table 4-1. 

Cross-walk of Substrata to LISS Habitats (Auster et al. 2009) 

Seascape: Fishers Island Sound 

Subsystem: Deep Subtidal 

Substratum Characteristics Habitat Sediment transport Class Su

Rock Hard bottom, boulders or 

large cobbles. 

Dominated by encrusting organisms: sponges, hydroids, algae, anemones and mobile epifauna. 

Assumed to be eroded ridges of glacial till or drift. Some periodic settlement of fines as drape over rock surfaces. 

Moraine or 

Boulder 

reef 

Bo

Shell Layer of disarticulated shells: 

common mussel (Mytilus), 

slipper shell (Crepidula), cockles (Cerastoderma) and clams (Ensis, Spisula, Mercenaria). 

Surface layer of clean shells and pebbles on coarse to fine sand. Infauna in layer of coarse shell hash overlying fine sand and silt. Some encrusting organisms on pebbles. 

Assumed to be area of active strong near-bed currents moving shells (absence of epifaunal growth). 

Moraine, 

Boulder 

reef or 

Sand dunes

P

Mobile Sand Fine sand with bedforms, 

isolated shells and pebbles. 

Active infauna including acorn worms (Saccoglossus), deep burrowing polychaetes. Some resistant epifauna on shells or isolated pebbles. 

Assumed to be area of moderate near-bed currents sufficient to periodically move sand in bedload. 

Sand dunes 

or Sand bar

S

Transitional Surface with shell layer and 

mud drape. 

Epifauna on shell layer and infaunal burrowing organisms. 

Episodic transport of shell alternating with deposition.

Basin, 

Sand bar or 

Artificial 

structure 

M

sed

Depositional Very fine sand or silt with no 

bedforms. Some isolated shells and pebbles. 

Dominated by deep burrowing infauna and some encrusting organisms (hydroids, bryozoans, anemones) on hard surfaces. 

Assumed to be low nearbed currents with very infrequent storm transport of surface sediment. 

Mud fields M
Page 41 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Figure 4-1. Representative images from western part of the study area 

 
Page 42 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Figure 4-2. Representative images from eastern part of the study area 

 
Page 43 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

Figure 4-3. Representative images from eastern-most reference areas
Page 44 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

5.0 REFERENCES 

AECOM. 2009. Monitoring Survey at the New London Disposal Site, July/ August 2007. 

DAMOS Contribution No. 180. U.S. Army Corps of Engineers, New England District, 

Concord, MA, 80 pp. 

Auster, P. J.; Heinonen, K. B.; Witharana, C.; McKee, M. 2009. A habitat classification scheme 

for the Long Island Sound region. Long Island Sound Study Technical Report. EPA Long 

Island Sound Office, Stamford, Connecticut 06904. 83 p. 

Carey, D. A.; Hickey, K.; Germano, J. D.; Read, L. B.; Esten, M. E. 2013. Monitoring Survey at 

the Massachusetts Bay Disposal Site September/October 2012. DAMOS Contribution 

No. 195. U.S. Army Corps of Engineers, New England District, Concord, MA, 87 pp. 

Carey, D. A.; Hahn, M.; Germano, J. D.; Little, D. I.; Bullimore, B. 2014. Marine Habitat 

Mapping of the Milford Haven Waterway, Wales, UK: Comparison of Facies Mapping 

and EUNIS Classification for Monitoring Sediment Habitats in an Industrialized Estuary. 

Journal of Sea Research, 2014, doi:10.1016/j.seares.2014.09.012. 

FGDC (Federal Geographic Data Committee). 2012. Coastal and Marine Ecological 

Classification Standard version 4, 353pp. 

Fredette, T. J.; French, G. T. 2004. Understanding the physical and environmental consequences 

of dredged material disposal: history in New England and current perspectives. Mar. 

Pollut. Bull. 49:93–102. 

Germano, J. D.; Rhoads, D. C.; Lunz, J. D. 1994. An Integrated, Tiered Approach to Monitoring 

and Management of Dredged Material Disposal Sites in the New England Regions. 

DAMOS Contribution No. 87. U.S. Army Corps of Engineers, New England Division, 

Waltham, MA, 67 pp. 

Germano, J. D.; Rhoads, D. C.; Valente, R. M.; Carey, D. A.; Solan, M. 2011. The use of 

Sediment-profile Imaging (SPI) for environmental impact assessments and monitoring 

studies – lessons learned from the past four decades. Oceanography and Marine Biology: 

An Annual Review 49: 247-310. 

Rhoads, D. C.; Germano, J. D. 1982. Characterization of organism-sediment relations using 

sediment profile imaging: An efficient method of remote ecological monitoring of the 

seafloor (REMOTS System). Mar. Ecol. Prog. Ser. 8:115–128. 

Rhoads, D. C.; Germano, J. D. 1986. Interpreting long-term changes in benthic community 

structure: A new protocol. Hydrobiologia 142:291–308. 

Shumchenia, E.; Guarinello, M.; Carey, D. A.; Lipsky, A.; Greene, J.; Mayer, L.; Nixon, M.; 

Weber, J. 2014. Inventory and comparative evaluation of seabed mapping, classification 

and modeling activities in the Northwest Atlantic, USA to support regional ocean 

planning. Journal of Sea Research, 2014, doi:10.1016/j.seares.2014.09.010. 

Stone, J. R.; Schafer, J. P.; London, E. H.; DiGiacomo-Cohen, M. L.; Lewis, R. S.; Thompson, 

W. B. 2005. Quaternary Geologic Map of Connecticut and Long Island Sound Basin, 

USGS Scientific Investigations Map 2784. 
Page 45 of 45 

DAMOS Data Summary Report – New London Disposal Site and Vicinity 

Sediment-Profile and Plan-View Imaging Survey, September 2014 

6.0 DATA TRANSMITTAL 

Data transmittal to support this data report will be provided as a separate deliverable for 

inclusion in a Technical Support Notebook. The data submittal will include: 

 Report figures and associated files, including an ArcGIS geo-database 

 Raw NEF and adjusted SPI/PV images 

 SPI/PV Field log, station location, and analysis tables 

 Pop-up and pull-out image files