OCS Study

BOEM 2016-073

Spatial and Temporal Distributions of 

Lobsters and Crabs in the Rhode 

Island/Massachusetts Wind Energy 

Area

US Department of the Interior 

Bureau of Ocean Energy Management

Office of Renewable Energy Programs

www.boem.gov
ii
OCS Study

BOEM 2016-073

Spatial and Temporal Distributions of 

Lobsters and Crabs in the Rhode 

Island Massachusetts Wind Energy 

Area

Authors

Jeremy Collie and John King

Prepared under BOEM Award 

M13AC00009

by

University of Rhode Island

Graduate School of Oceanography

Narragansett, RI 02882

November 4, 2016
DISCLAIMER

Study collaboration and funding were provided by the US Department of the Interior, Bureau of Ocean 

Energy Management, Environmental Studies Program, Washington, DC, under Contract Number 

M13AC00009. This report has been technically reviewed by BOEM and it has been approved for 

publication. The views and conclusions contained in this document are those of the authors and should 

not be interpreted as representing the opinions or policies of the US Government, nor does mention of 

trade names or commercial products constitute endorsement or recommendation for use.

REPORT AVAILABILITY

To download a PDF file of this Atlantic OCS Region report, go to the US Department of the 

Interior, Bureau of Ocean Energy Management, Environmental Studies Program Information 

System website and search on OCS Study BOEM 2016-073.

This report can be viewed at select Federal Depository Libraries. It can also be obtained from the 

National Technical Information Service; the contact information is below.

US Department of Commerce

National Technical Information 

Service 5301 Shawnee Rd.

Springfield, VA 22312

Phone: (703) 605-6000, 1(800)553-6847

Fax: (703) 605-6900

Website: http://www.ntis.gov/

CITATION

Collie, J.S. and King, J.W. 2016. Spatial and Temporal Distributions of Lobsters and Crabs in the Rhode 

Island Massachusetts Wind Energy Area. US Dept. of the Interior, Bureau of Ocean Energy

Management, Atlantic OCS Region, Sterling, Virginia. OCS Study BOEM BOEM 2016-073. 

48 pp.

Cover graphic by Anna Malek
i

Spatial and Temporal Distributions of Lobsters and Crabs in the 

Rhode Island Massachusetts Wind Energy Area

Contents

List of Figures ................................................................................................................................................ iii

List of Tables .......................................................................................................................................v

Abbreviations and Acronyms ...............................................................................................................v

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

1.1 Project objectives ..................................................................................................................................... 2

2. Survey Design and Description ......................................................................................................2

2.1 Description of the Sampling Gear ........................................................................................................ 3

3. Summary of Biological Sampling ....................................................................................................3

3.1 Data parameters collected for individual lobsters ............................................................................. 4

4. Habitat Studies and Classification ..................................................................................................5

4.1 Mapping ............................................................................................................................................ 5

4.2 Groundtruth ....................................................................................................................................... 6

4.3 Data integration and aliquot bottom type classification ..................................................................... 7

5. Bottom Temperature ...................................................................................................................13

6. Lobster Statistics .........................................................................................................................15

7. Bycatch Species ...........................................................................................................................24

7.1 Jonah crabs.............................................................................................................................................. 28

8. Pilot Tagging Study ......................................................................................................................32

9. Conclusions .................................................................................................................................36

9.1 Implications for siting and monitoring of wind energy development .............................................. 36

9.2 Recommendations for future research ............................................................................................ 37
ii

References .................................................................................................................................. 39

Appendix 1. List of Project Personnel ........................................................................................... 41

Appendix 2. Grab Samples Collected for Ground-truthing ............................................................ 42

Appendix 3. Coordinates of Sampling Locations, Depth, and Habitat Classification ........................ 43

Appendix 4. Data from tagged and recaptured lobsters ................................................................ 47

Appendix 5. Description and Disposition of the Database ............................................................. 48
iii

List of Figures

Figure 1. Study site in the Rhode Island/Massachusetts Lease Area. Coordinates and depths of the 

sampling locations are given in Appendix 3 ...........................................................................................4

Figure 2. Detail of the study area showing the 24 lease blocks (black boxes), the 2014 aliquots (purple 

boxes), and the 2015 aliquots (red boxes) .............................................................................................5

Figure 3. Bottom type classifications of aliquots sampled by SNECVTS.................................................8

Figure 4. Sidescan sonar of Aliquot 2 and bottom photograph taken at grab-sample station 41, 

representing the “soft sediments” category ..........................................................................................9

Figure 5. Sidescan sonar of Aliquot 9 showing the transition from sand to boulders and bottom 

photograph of the “boulder on sand” category taken at grab-sample station 48.................................10

Figure 6. Sidescan sonar of Aliquot 11 and bottom photograph taken at grab-sample station 54, 

showing a boulder habitat......................................................................................................................11

Figure 7. Sidescan sonar of Aliquot 38 and bottom photograph taken at grab-sample station 118, 

illustrating the “medium to course sand” category ...............................................................................12

Figure 8. Daily bottom temperatures at each aliquot in 2014 and 2015. The boxes correspond with the 

lease blocks shown in Fig. 2....................................................................................................................13

Figure 9. Bottom temperature by month and year. Each subplot corresponds with the study area 

shown in Fig. 2. The lines are contours of bottom temperature in degrees Fahrenheit .......................14

Figure 10. Lobster abundance by aliquot in 2014 and 2015 ..................................................................16

Figure 11. Incidence of shell disease by aliquot in 2014 ........................................................................17

Figure 12. Incidence of shell disease by aliquot in 2015 ........................................................................18

Figure 13. Length-frequency distributions of lobsters in ventless traps, by year and month................19

Figure 14. Length-frequency distributions of lobsters in standard traps, by year and month...............20

Figure 15. Distribution of lobster catches (red bars) in relation to bottom temperature (black lines) in 

2014. The boxes correspond with the lease blocks shown in Fig. 2.......................................................21

Figure 16. Distribution of lobster catches (red bars) in relation to bottom temperature (black lines) in 

2015. The boxes correspond with the lease blocks shown in Fig. 2.......................................................22
iv

Figure 17. Results of the Generalized Additive Model fit to lobster abundance per trawl in 2014 and 

2015. The subplots show the linear predictors (partial effects) of bottom temperature (oF), depth (ft), 

latitude (N) and longitude (E) ................................................................................................................24

Figure 18. Jonah crab, Cancer borealis, abundance was highest in the central blocks of the lease area. 

This abundance pattern was consistent between 2014 and 2015.........................................................26

Figure 19. Rock crabs Cancer irroratus, were generally abundant throughout the lease-block area, with 

no clear spatial pattern or differences in abundance between 2014 and 2015 ....................................26

Figure 20. Red hake, Urophysis chuss, was more abundant in the southern blocks of the lease area 

(aliquots 12-24). Overall abundance was lower in 2015 than in 2014..................................................27

Figure 21. Black seabass, Centropristis striata, abundance was highest in the most northern and most 

southern aliquots, with lower abundance in between. Overall abundance was lower in 2015 than in 

2014 ........................................................................................................................................................27

Figure 22. Length-frequency distributions of Jonah crabs by year and month. Dark bars are females and 

light bars are males.................................................................................................................................29

Figure 23. Results of the Generalized Additive Model fit to Jonah crab abundance per trawl in 2014 and 

2015. The subplots show the linear predictors (partial effects) of bottom temperature (°F), depth (ft), 

latitude (N), and longitude (E) ................................................................................................................31

Figure 24. Lobster tagged on 14 August 2015 ........................................................................................32

Figure 25. Distance traveled by lobsters from the point of tagging to the point of recapture, days 

between tagging and recapture and estimated velocity........................................................................33

Figure 26. Tagging and recapture locations of lobsters tagged on 14 August 2015 and recaptured in the 

vicinity of the RI/MA Lease Area ............................................................................................................34

Figure 27. Tagging and recapture locations of all lobsters tagged on 14 August 2015..........................35
v

List of Tables

Table 1. Frequency of soak times by year...............................................................................................3

Table 2. CMECS Substrate Component Classification for all bottom type categories defined in this study

................................................................................................................................................................7

Table 3. Total catches of lobsters and Jonah crabs by year and aliquot ...............................................15

Table 4. Sex ratio and percent of female lobsters with eggs by year and month ..................................16

Table 5. Incidence of shell disease by year and month ..........................................................................18

Table 6. Generalized additive model fit to the abundance of lobsters in 2014 and 2015. A Poisson 

model with a log link was specified because the data are counts per trawl. .......................................23

Table 7. Total numbers of species other than lobsters caught in the SNECVTS survey .........................25

Table 8. Total catch, and proportional catch by sex of Jonah crabs in 2014 and 2015. Total numbers of 

males and females by month were calculated by multiplying the total catch by sex proportion in the 

subset of measured crabs.......................................................................................................................28

Table 9. Generalized additive model fit to the abundance of Jonah crabs in 2014 and 2015. A Poisson 

model with a log link function was specified because the data are counts per trawl ...........................30

Table 10. Table 10. Comparison of catch per trap between SNECVTS and the RI DEM ventless trap 

survey, which is conducted in RI state waters........................................................................................36

Abbreviations and Acronyms

ASMFC Atlantic States Marine Fisheries Commission

BOEM Bureau of Ocean Energy Management 

MADMF Massachusetts Division of Marine Fisheries

OCS Outer Continental Shelf

RIDEM Rhode Island Department of Environmental Management

RIS Rhode Island Sound

SNECVTS Southern New England Cooperative Ventless Trap Survey

WEA Wind Energy Area
1

1. Introduction

A goal of marine spatial planning is to aid in siting activities in areas that will minimize, to the 

extent possible, the cumulative impacts on resident species while maintaining the ecological and 

economic services derived from near-shore regions (Crowder & Norse 2008). A core challenge 

of developing a spatial management plan is the acquisition of knowledge concerning the 

distributions, population structures, interactions and trends of key species and communities 

(Foley et al. 2010). Some work addressing these knowledge gaps has been undertaken in the 

vicinity of the study area for this project, the Rhode Island/Massachusetts Wind Energy Area 

(RI/MA Lease Area) in Southern New England. Rhode Island’s Ocean Special Area 

Management Plan compiled the available knowledge of finfish, shellfish and fisheries in the 

offshore waters of RI (Olsen et al. 2014). Trawl surveys throughout Rhode Island Sound and 

Block Island Sound have begun to characterize fish populations (Malek et al. 2014), but spatial 

coverage is limited by the presence of fixed fishing gear, such as gillnets and lobster trawls, and 

the inaccessibility of rocky bottom. Consequently, the distribution and dynamics of the 

American lobster (Homarus americanus), one of the most valuable species in New England, is 

poorly understood (ASMFC 2009). With the leasing of areas for offshore wind-energy 

development, it is essential to evaluate the baseline status of the lobster population in the RI/MA 

Lease Area, to inform the siting of wind turbines within the lease area and to monitor the 

potential impacts of wind turbine construction. 

The American lobster fishery remains one of the most valuable fisheries in Southern New 

England, with 2013 landings of 3.3 million pounds worth $15 million in revenue (ASMFC 

2015). Massachusetts and Rhode Island are the primary contributors to the Southern New 

England lobster fishery, supporting fleets of 1500 and 250 vessels, respectively (MADMF 2010, 

Hasbrouck et al. 2011). In addition to nearly 2000 commercial fishing jobs, the southern New 

England lobster fishery also sustains a variety of support businesses, such as trap-builders, gear 

suppliers, bait and ice dealers, shipyards, fuel companies, engine sales and repair businesses, and 

marine electronic retailers. Since peaking in the late 1990s, the Southern New England lobster 

stock has become severely depleted, especially the inshore component of the stock, where 

environmental conditions have remained unfavorable for lobsters (ASMFC 2015). Since 2008, a 

higher percentage of landings has come from the offshore stock component.

This report is a product of the Southern New England Cooperative Ventless Trap Survey

(SNECVTS) which developed a baseline for measuring the cumulative effects of offshore 

development projects in the RI/MA Lease Area. In addition, the survey was designed to 

contribute to the assessment of the Southern New England lobster stock, which is currently at a 

low level of abundance (ASMFC 2010). The study was necessary to establish the preconstruction status of the lobster population, without which potential effects post construction 

would not be discernable from the effects of fishing and other population stressors (Schmitt & 

Osenberg 1998). To the extent possible, this project followed ASMFC survey protocols and 

adhered to the Atlantic Coastal Cooperative Statistics Program data requirements.
2

1.1 Project objectives

The objectives of this two-year study were as follows:

a. Establish a ventless trap survey protocol to assess the potential impacts of wind energy 

development in the RI/MA Lease Area and the northwestern portion of Massachusetts Lease 

Area. 

b. Determine the seasonal and spatial patterns of lobster abundance within these development 

areas.

c. Conduct two years of pre-development monitoring that will allow Before-After and ControlImpact (BACI) comparisons to be made. This monitoring survey will establish pre-construction 

conditions. Continuation of monitoring during construction and post-construction will assess 

possible impacts in the context of a regional database. 

2. Survey Design and Description

This survey was a cooperative project that included representatives of the Rhode Island lobster 

industry, the University of Rhode Island, and Roger Williams University. The vessel captains 

and their fishing vessels are:

Lanny Dellinger, F/V Megan and Kelsey, Newport, RI

Greg Mataronas, F/V Cailyn Grace, Sakonnet Point, RI

Brian Thibeault, F/V Ashley Ann, Point Judith, RI

Twenty-four lease blocks in the RI/MA Lease Area were selected for this study after discussions 

with BOEM and lobster industry representatives (black boxes Fig. 1). These blocks were 

selected based on their potential development for wind energy, and the practicality of conducting 

a monitoring survey with lobster boats. In consultation with the lobstermen, five aliquots (1/16 

of a BOEM lease block) that would be suitable for the survey were selected from each lease 

block, given known fishing grounds and gear conflicts. One of these five aliquots from each 

lease block was randomly chosen for sampling, along with another aliquot as an alternate. A 

new set of sampling aliquots was randomly chosen each year (2014 and 2015), for a total of 48 

aliquots (Fig. 2). This sampling design provided a broad coverage over the selected lease blocks 

with randomized placement within each lease block. This stratified random design allows the 

results from the selected stations to be generalized over the study area. The sampling density 

translates to one station per 9 square nautical miles. The coordinates of the selected aliquots are 

listed in Appendix 3.

The sampling design employed in this project is consistent with Atlantic States Marine Fisheries 

Commission (ASMFC 2010) ventless trap survey, in which stations are selected randomly at the 

start of the season and are then retained for the duration of the year. New stations are then 

randomly selected each year. Maintaining fixed locations approximates the operations of 

commercial lobstermen, keeps the locations occupied, and reduces the time spent moving gear.
3

2.1 Description of the sampling gear

Trap design

• 40” length × 21” width × 16” height

• Single parlor

• 5” entrance hoops

• 1” square rubber coated 12-gauge wire

• Standard shrimp mesh netting

• Wood runners with three “ergo” blocks

• 4” × 6” disabling door

• One rectangular vent with dimensions 5-3/4” length × 1-15/16” height

This trap design is consistent with ASMFC coastwide, ventless trap surveys (ASMFC 2010). 

Traps were deployed on ten-pot trawls with 100-ft separation between traps. Six ventless traps 

were alternated with four standard traps so that the data can be compared with commercial catch 

rates, resulting in a trap pattern of (V-S-V-S-V-V-S-V-S-V). Longer trawls are required offshore 

(than inshore) to provide more total weight and for ease of recovery in the event that buoys are 

lost. 

3. Summary of Biological Sampling 

Given the spatial extent of the study area, three commercial lobster boats were needed to conduct 

the survey. An additional vessel was on standby in case of mechanical problems with the 

primary vessels. Each boat was responsible for eight trawls (80 traps) in a particular segment of 

the overall study area (Fig. 2). Each boat sampled eight stations over four days each month. The 

first day was allocated to baiting the traps with skate and the remaining three days to sampling 

the lobsters. The target soak time (number of days between baiting and sampling) was five days, 

which differs from the three-day soak time used in state ventless trap surveys. A longer soak 

time was used because lower densities of lobsters were expected offshore compared with inshore 

areas of Maine and Massachusetts, and because of the logistics of sampling offshore. After the 

third sampling day, the traps were disabled for the remainder of the month. On-board data 

sampling was conducted by two qualified biologists. Data were collected on audio recorders and 

transcribed onto computer tablets. Over the course of two years, a total of 8640 trap hauls were 

sampled.

Table 1. Frequency of soak times by year.

Year 4 Days 5 Days 6 Days 7 Days Totals

2014 1 343 56 24 432

2015 48 272 104 8 432

All trap hauls were made within the acceptable window of 3 to 7-day soak time (Table 1). The 

majority of soak times were 5 days; deviations from the target were due to adverse weather 

conditions. 
4

3.1 Data parameters collected for individual lobsters:

• Carapace length (mm) measured with calipers

• Sex (determined by examining the first pair of swimmerets)

• Presence or absence of eggs

• Cull status (claws missing, buds, or regenerated)

• V-notch status (presence or absence)

• Mortality (alive or dead)

• Incidence of shell disease (none, moderate, severe)

Legal sized lobsters were not retained for sale. All lobsters were returned to the water in the area 

where they were caught before moving to the next station. The target species was lobster, but 

crabs and demersal fish species were also enumerated as “bycatch.” Up to 10 Jonah crabs 

(Cancer borealis) per trap were measured and their sex recorded; if more than 10 Jonah crabs 

were caught, a subsample of 10 was measured. The physical variables collected at each station 

included latitude, longitude, depth, temperature, sea state, and wind direction and velocity. 

Bottom temperature was measured with data loggers, one of which was attached to each trawl. 

Wind direction and velocity were measured with a hand-held weather meter. 

Figure 1. Study site in the Rhode Island/Massachusetts Lease Area. Coordinates and 

depths of the sampling locations are given in Appendix 3. 
5

Figure 2. Detail of the study area showing the 24 lease blocks (black boxes), the 2014 

aliquots (purple boxes), and the 2015 aliquots (red boxes). Note that three 2015 aliquots 

(30, 41, and 43) were repeats from 2014; all the other aliquots were distinct. 

4. Habitat Studies and Classification

The sedimentary composition of each sampling site was characterized with sidescan sonar, 

followed by ground-truth data consisting of three grab samples taken along the transect where 

the traps were set. In addition, a video camera on the grab sampler provided visual confirmation 

of habitat type. 

4.1 Mapping

The sidescan sonar survey was conducted with a Teledyne Benthos 200 kHz C3D interferometric 

sonar, pole-mounted along the starboard side of a 42-ft survey vessel. Data were collected with 

GeoDas software developed by Ocean Imaging Consultants (OIC) and monitored topside in realtime to ensure that adequate data quality and coverage were being achieved. The data were 

collected in association with an Applanix POS MV system to assure positional accuracy and to 

correct for vessel motion (pitch, roll, heave). The survey was designed to cover the lobster trap 
6

sites and some of the surrounding area within the aliquot sites for context. As such, the survey 

design at each of the 48 sites was composed of two parallel track lines approximately 600-800 m 

in length. Depending on survey conditions, line spacing was set to 100 m or 150 m and sonar 

swath range was set to 130 m or 200 m, respectively, to ensure overlap with adjacent lines for 

full-coverage data. 

The raw sidescan records were processed with OIC CleanSweep software. The process followed 

standard techniques of bottom-tracking the data and then applying angle-varying gains (AVG) 

and look-up tables (LUT) as necessary to correct for water-column returns, arrival angle, and 

contrast to produce color-balanced sidescan sonar images. All of the data were examined 

manually to confirm quality and accuracy. The horizontal coordinate system was set to UTM 

Zone 19N and the data were exported at 1-m pixel resolution. The images are displayed as an 

inverse gold color scale, with pixel values ranging from zero (dark gold) to 255 (white). The 

lighter pixels indicate hard acoustic returns and represent the presence of hard surficial sediments 

(e.g. coarse sand, cobbles, and boulders), whereas darker pixels represent the presence of soft 

sediments, which tend to absorb sound to a greater degree. 

4.2 Ground-truth

The ground-truth survey consisted of two components: grab samples and video. Surficial 

samples of the seafloor, or “grab samples” were collected with a Smith-McIntyre grab sampler 

(0.058 m2 area). In addition, a GoPro camera was affixed to the grab sampler to simultaneously 

capture co-located high-definition video imagery. Ground-truth data were collected at three 

locations within each site, except when sites from 2014 and 2015 overlapped (this occurred three 

times), for a total of 135 samples at 45 sites. The locations were chosen by visual examination of 

the sidescan sonar imagery and positioned to capture all distinct geophysical bottom types at a 

site. If the bottom type was consistent throughout the site, then the ground-truth locations were 

about evenly spaced over the site. 

A sub-sample of sediment from each grab sample was analyzed with a particle size analyzer 

(Malvern Mastersizer 2000E). The analyzer provided the percent composition of sediment grain 

size fractions (excluding gravel) according to the Wentworth scale (Wentworth 1922). Dominant 

grain sizes fell into the following categories: clay, silt, fine sand, medium sand and coarse sand. 

The remaining material from each sample was sieved on a 1-mm mesh sieve; the organisms 

retained were preserved in a solution of formalin and rose bengal and archived for future benthic 

biological community analysis. 

4.3 Data Integration and Aliquot Bottom Type Classification

Habitat categories were chosen that are relevant to this lobster study and also consistent with the 

substrate component of the CMECS classification framework. The substrate component was the 

only component that could be applied to the datasets collected for this study (Table 2). Substrate 

component classifications from this study were cross-validated in areas within Rhode Island and 

Block Island Sounds where the CMECS classification framework had been applied in previous 

studies (LaFrance et al. 2010; LaFrance et al. 2014). This validation was done to confirm the 

interpretations from this project and to ensure consistency in the classification. Previous 

comparisons and analyses within the study area of this project have shown that the surface 
7

sediment typically falls into one of two categories: fine sediments (which includes clay, silt, very 

fine sand, and fine sand) and coarse sediments (which includes medium sand, coarse sand, and 

very coarse sand).

Still frames from the GoPro video footage were analyzed to visually determine a bottom-type 

description at each ground-truth site. Records of habitat characteristics included the following 

components when available: general surficial sediment type (e.g. sandy bottom), presence and 

extent of gravel cover from granule to boulder size, presence of shell hash, and observable 

macro-biota. In addition, qualitative descriptions of grab samples (Appendix 2) were used to 

supplement video analysis, particularly when visibility in video footage was limited. Sidescan 

sonar images were also used to differentiate between sample sites with and without large 

boulders. When possible, video footage was in turn used to corroborate these classifications; i.e. 

when boulders were evident in video footage, boulders were consistently present in 

corresponding sonar images. 

Once analysis of the sidescan sonar, sediment grain size, and video data was completed, the 

various datasets were integrated and used to characterize the bottom type of each ground-truth 

sample site. The first step in this process was to confirm agreement between the data types at 

each site; once this confirmation was completed, sample sites were classified according to 

dominant sediment grain size and presence of boulders. The bottom type for each lobster 

sampling aliquot was determined by integrating habitat data from all three of its ground-truth 

sample sites.

Table 2. CMECS Substrate Component Classification for all bottom type categories defined in 

this study.

Component Code Unit Code Origin Class Subclass Group Subgroup

S 1.2.2 Geologic 

Substrate

Unconsolidated 

Mineral Substrate

Fine 

Unconsolidated 

Substrate

See below See below

CMECS Substrate Component 'Group' and 'Subgroup' Classifications defining Bottom Type 

Categories

Bottom Type Category Unit Code Group Subgroup CMECS Modifier

Soft Sediment 1.2.2.2.4 Sand Fine Sand

1.2.2.2.5 Sand Very Fine Sand

1.2.2.3.1-3

Muddy 

Sand

Silty Sand, SiltyClayey Sand

1.2.2.4.1-3

Sandy 

Mud

Sandy Silt, Sandy SiltClay, Sandy Clay

1.2.2.5.1-3 Mud Silt, Silt-Clay, Clay

Medium to Coarse Sand 1.2.2.2.1 Sand Very Coarse Sand

1.2.2.2.2 Sand Coarse Sand

1.2.2.2.3 Sand Medium Sand

Boulders on Sand 1.2.2.2.2 Sand Very Coarse Sand Boulders

1.2.2.2.3 Sand Coarse Sand Boulders

Transition Zone* Combination of above categories

*Transition Zone indicates that the habitat encompasses more than one of the other habitat categories 
8

The number of bottom-type categories was not pre-defined; instead, aliquots with similar 

characteristics were grouped together as appropriate. The bottom-type categories were given 

names believed to be meaningful to the end user. Four habitat categories were generated: soft 

sediments (comprising clay, silt, very fine sand, and fine sand), medium to coarse sand 

(comprising of medium, coarse, and very coarse sands), boulders on sand (boulders on medium 

to coarse sand), and transition zone (where a change in bottom type was evident within an 

aliquot). These categories along with their corresponding CMECS classifications are given in 

Table 2. 

The habitat classification of each aliquot is listed in Appendix 3 and mapped in Fig. 3. Bottom 

types are patchily distributed throughout the lease area. Medium to coarse sand occurs 

throughout the study area. Soft sediments are confined to the northern, deeper aliquots. 

Boulders on sand occurred in the southwest and central aliquots. Finally, the transition zone 

habitat occurred in two central and two eastern aliquots. Figures 4 through 7 show representative 

examples of each habitat type.

Figure 3. Bottom type classifications of aliquots sampled by SNECVTS.
9

Figure 4. Sidescan sonar of Aliquot 2 and bottom photograph taken at grab-sample station 41, 

representing the “soft sediments” category.
10

Figure 5. Sidescan sonar of Aliquot 9 showing the transition from sand to boulders and bottom 

photograph of the “boulder on sand” category taken at grab-sample station 48.
11

Figure 6. Sidescan sonar of Aliquot 11 and bottom photograph taken at grab-sample station 54, 

showing a boulder habitat.
12

Figure 7. Sidescan sonar of Aliquot 38 and bottom photograph taken at grab-sample station 

118, illustrating the “medium to course sand” category.
13

5. Bottom temperature

Continuous records of bottom temperature were made from May to October in each aliquot. The 

raw data were collected at 30-minute intervals. They have been averaged over daily intervals 

(Fig. 8) for comparison with the lobster catches and over monthly intervals for presentation (Fig. 

9). In May the shallower, eastern aliquots warm more quickly than the western, deeper aliquots. 

This temperature gradient is maintained throughout the summer, until the bottom water begins to 

cool. In October, the shallower, eastern aliquots cool more rapidly than the deeper, western 

aliquots. 

Following the cold winter of 2015, bottom-water temperatures were several degrees cooler in 

May 2015 than in May 2014 (Fig. 8). After rapid warming, bottom temperatures in June 2015 

were equivalent to June 2014. The maximum temperature reached was lower in 2015 than in 

2014, when bottom temperature exceeded 20° C in aliquots 23 and 24 at the end of September. 

2014

2015 A 1 A 2

A 3 A 4 A 5

A 6 A 7 A 8 A 9 A 10 A 11

A 12 A 13 A 14 A 15 A 16 A 17 A 18 A 19

A 20 A 21 A 22 A 23 A 24

Figure 8. Daily bottom temperatures at each aliquot in 2014 and 2015. The boxes 

correspond with the lease blocks shown in Fig. 2.
14

 6.8 

 7.2 

 7.4 

 7.6 

 7.8 

2014

May

 9.2 

 9.2 

 9.2 

 9.4 

 9.6 

 9.8 

 10 

June

 10.6 

 10.8 

 10.8 

 11 

 11.2 

 11.4 

 12 

July

 12 

 13 

 13 

 13.5 

 14 

August

 15.5 

 16 

 16.5 

 17 17.5 

September

 17.2 

 17.3 

 17.4 

 17.5 

 17.7 17.8 

 17.9 

 18 

October

 5.2 

 5.4 

 5.6 

 5.8 

 6.2 

 6.4 

 6.6 

 7 

2015

 9.2 

 9.4 

 9.6 

 9.6 

 9.8 

 9.8 

 10 10.2 

 10.4 

 10.6 

 10.6 

 10.8 

 11 

 11.4 

 11.8 

 12 

 12.2 

 12.2 

 12.4 

 12.6 

 12.8 

 13 

 13.4 

 14 

 14 

 14.4 

 14.6 

 14.8 

 15 

 15.2 

 15.6 

 16.85 

 16.95 

 17.05 

 17.1 

 17.15 

 17.2 

Figure 9. Bottom temperature by month and year. Each subplot corresponds with the 

study area shown in Fig. 2. The lines are contours of bottom temperature in degrees 

Celsius.
15

6. Lobster Statistics

In general, lobster catches were higher on the eastern side of the study area (Fig. 10). In 2014 

the highest lobster catches were from aliquots 10 and 11 (Table 3), which are located in the 

northeast of the lease block area (refer to Fig. 2). High catches were also obtained from aliquots 

2, 9, and 17, which are also on the northeast side of the lease block area. In 2015, the total 

lobster catch was slightly lower and the catches were distributed more evenly across aliquots. 

The highest catches were obtained in aliquots 41 and 42, which are on the east side of the study

area. High catches were also obtained from aliquots 26, 30, 35, 40, and 43.

Table 3. Total catches of lobsters and Jonah crabs by year and aliquot. Note that aliquots in the 

same row are in the same lease blocks. Aliquots 6 and 30, 17 and 41, and 19 and 43 refer to 

the same aliquots in different years.

2014 2015

Aliquot Lobsters Jonah Crabs Aliquot Lobsters Jonah Crabs

1 495 1482 25 376 1342

2 663 1604 26 449 1167

3 444 1600 27 333 1049

4 304 1213 28 469 1157

5 529 1224 29 428 1318

6 424 2136 30 464 1138

7 241 1544 31 276 1068

8 245 1443 32 337 835

9 627 1257 33 299 932

10 1235 1246 34 284 1587

11 1140 1067 35 437 1014

12 340 531 36 354 325

13 221 725 37 158 660

14 309 3197 38 252 830

15 434 890 39 409 913

16 685 1390 40 430 496

17 801 740 41 594 431

18 374 655 42 889 396

19 197 1367 43 449 664

20 207 787 44 182 972

21 173 1749 45 385 913

22 180 1953 46 326 717

23 235 1091 47 206 960

24 253 583 48 288 349

Totals 10,756 31,474 9,074 21,233
16

Figure 10. Lobster abundance in 2014 and 2015 by aliquot.

Table 4. Sex ratio and percent of female lobsters with eggs by year and month.

Year Month Female Male Percent 

female Eggers % females with eggs

2014 May 357 60 85.61 231 64.71

June 668 120 84.77 231 34.58

July 1336 936 58.80 93 6.96

August 1772 1451 54.98 56 3.16

September 1386 1177 54.08 176 12.70

October 966 527 64.70 253 26.19

2015 May 199 36 84.68 132 66.33

June 279 128 68.55 149 53.41

July 535 554 49.13 44 8.22

August 1329 1540 46.32 37 2.78

September 1293 1515 46.04 112 8.66

October 886 778 53.25 237 26.75
17

Lobster catches in the SNECVTS survey were dominated by females in spring and early summer 

(Table 4). In both years the percentage of females started at about 85% in May and decreased 

toward an equal sex ratio in July through September. The percentage of females increased again 

in October. In 2014, the percentage of females never decreased below 50%, whereas in 2015 it 

decreased to 46%. The percentage of females with eggs was highest in May when females 

dominated the catches. Females incubate their eggs until the larvae hatch from mid-May to midJune (ASMFC 2015). The percent of females with eggs declined to a minimum in August and 

then increased to 26% in October of both years, as the next generation was incubated. The 

dominance of females in May and June can therefore largely be explained by the presence of 

egg-bearing females, which are protected from capture. Given the high exploitation rates of 

legal-sized lobsters, these females rapidly disappear from the population once they shed their 

eggs.

Figure 11. Incidence of shell disease by aliquot in 2014.

The incidence of shell disease was generally low in the SNECVTS survey. In 2014, shell disease 

incidence was lower in the offshore aliquots (Fig. 11). In 2015, shell disease incidence was 

lower overall, especially on the eastern side of the lease block area (Fig. 12). Lower incidence of 

shell disease in 2015 could be explained by lower bottom water temperature in spring 2015 

(Figs. 8 and 9). The incidence of severe shell disease was higher in the near-shore lease blocks. 
18

Shell disease incidence was highest in May to June, and then decreased below 10% in August 

and September as more of the lobsters had recently molted (Table 5). Following the molting 

period, shell disease incidence increased moderately in October. The incidence of shell disease 

therefore follows the annual molt cycle of lobsters (Castro and Angell 2000).

Figure 12. Incidence of shell disease by aliquot in 2015.

Table 5. Incidence of shell disease by year and month.

Frequency Percentage

Year Month Moderate None Severe Moderate None Severe

2014 May 220 158 39 52.76 37.89 9.35

June 396 277 115 50.25 35.15 14.59

July 469 1673 130 20.64 73.64 5.72

August 236 2952 35 7.32 91.59 1.09

September 153 2374 36 5.97 92.63 1.40

October 391 1068 34 26.19 71.53 2.28

2015 May 89 106 40 37.87 45.11 17.02

June 135 193 79 33.17 47.42 19.41

July 186 811 92 17.08 74.48 8.45

August 125 2689 56 4.36 93.69 1.95

September 180 2584 45 6.41 91.99 1.60

October 231 1394 39 13.88 83.77 2.34
19

0 20 40 60 80

2014

May

0 40 80 120

June

0 100 300

July

0 200 400

August

0 200 400

September

40 50 60 70 80 90 105 120 135

0 50 150 250

October

0 10 20 30

2015

0 10 30 0 50 100 0 200 400 0 200 400

40 50 60 70 80 90 105 120 135

0 100 200 300

Carapace length (mm)

Figure 13. Length-frequency distributions of lobsters in ventless traps, by year and month. 

Dark bars are females and light bars are males.
20

0 10 20 30 40

2014

May

0 20 40 60 80

June

0 50 150

July

0 50 150

August

0 50

September

100

40 50 60 70 80 90 105 120 135

0 40 80

October

0 5 10 15 20

2015

0 5 15 25 0 20 40 60 80 0 50 150 0 50 100

40 50 60 70 80 90 105 120 135

0 40 80 120

Carapace length (mm)

Figure 14. Length-frequency distributions of lobsters in standard traps, by year and month. 

Dark bars are females and light bars are males.
21

Lobsters ranged from 20 to 196 mm carapace length. However, the majority of lobsters were 

between 40 and 120 mm (Figs. 13 and 14). May and June catches contained large females, a 

high proportion of which carried eggs (Table 4) and were therefore protected from exploitation. 

Once the eggs are released these females are no longer protected from exploitation and the size 

distributions became more truncated beyond the legal size of 85.7 mm. Smaller lobsters were 

more numerous in the summer months, with a high proportion of males. These smaller lobsters 

may have just molted into the 60 to 80 mm length class and become vulnerable to capture. As 

expected, the standard traps caught few lobsters smaller than 80 mm (Fig. 13). An exception 

was June 2015, when numerous male lobsters between 60 and 80 mm were caught in standard 

traps.

Figure 15. Distribution of lobster catches (red bars) in relation to bottom temperature (black 

lines) in 2014. The boxes correspond with the lease blocks shown in Fig. 2. 

In 2014, lobster catches were consistently higher in aliquots 10 and 11 (Table 3, Fig. 15). These 

high catches are partially explained by the warmer water temperatures in the northeast of the 

lease block area; this temperature gradient persisted through September, after which catch rates 

decreased. In 2015, lobster catches were low in May and June in most aliquots, owing to low 

bottom temperatures (Fig. 16). With warming temperatures, the highest catches were obtained in 

August, September, and early October.

A 1 A 2

A 3 A 4 A 5

A 6 A 7 A 8 A 9 A 10 A 11

A 12 A 13 A 14 A 15 A 16 A 17 A 18 A 19

A 20 A 21 A 22 A 23 A 24
22

The seasonal onshore-offshore migrations of American lobster are understood as a strategy to 

maintain high local ambient temperatures to maximize the degree days needed for molting, 

growth, gonad development, egg extrusion (Cooper and Uzman 1986) and egg development 

(Campbell 1986). As bottom temperature warms in the spring, lobsters migrate onshore to 

shallower depth. As water in shallower depths cools more rapidly in fall, lobsters return to 

deeper offshore water. This strategy can explain the increasing catches in the SNECVTS survey 

from May through August, followed by declines in October. 

A 25 A 26

A 27 A 28 A 29

A 30 A 31 A 32 A 33 A 34 A 35

A 36 A 37 A 38 A 39 A 40 A 41 A 42 A 43

A 44 A 45 A 46 A 47 A 48

Figure 16. Distribution of lobster catches (red bars) in relation to bottom temperature (black 

lines) in 2015. The boxes correspond with the lease blocks shown in Fig. 2. 

A series of generalized additive models (GAMs) was fit to explain the spatio-temporal variability 

of lobster abundance as smooth functions of predictor variables. The dependent variable was the 

sum of lobster catches by aliquot and date. Year and habitat type (Appendix 3) were entered as 

factors. Bottom temperature and depth were fit with spline functions. Day of year was not 

included as an independent variable because it is highly correlated (0.96) with temperature. The 

interaction between longitude and latitude was included to explain any residual geographic 

variation not explained by the other predictor variables. For this interaction term, the number of 

knots was constrained to k=12 to avoid over-fitting the data.

All the independent variables were nominally significant except for year, which was removed. 

The final model explained 61.8% of the deviance in lobster counts (Table 6). The habitat 
23

coefficients are measured relative to Boulders with sand, which is assigned a value of 0. 

Therefore, the habitat types, ranked by lobster abundance are Transition zone, Boulders with 

sand, Medium to course sand, and Soft Sediment. Lobster abundance increased rapidly with 

temperature up to a peak at ~14 oC (Fig. 17). The temperature effect appears to increase again 

above 17 oC but there are fewer observations at high temperature. At higher temperatures, 

lobsters may begin to migrate south to deeper, cooler water (see Section 8). Depth had a smaller 

effect on lobster abundance, partly because of the limited depth range of the aliquots. Since 

there were no aliquots between 25 and 32 m, the decline seen in this interval could be 

confounded with some other variable. Beyond 32 m, lobster abundance increased to a maximum 

around 42 m. The interaction between longitude and latitude shows a pattern of high abundance 

in the northeast and lower abundance in the southwest corners of the lease-block area.

Table 6. Generalized additive model fit to the abundance of lobsters in 2014 and 2015. 

A Poisson model with a log link was specified because the data are counts per trawl. 

Significance codes: *** < 0.001, ** < 0.01, * < 0.05.

__________________________________________________________________________

Formula: lobs ~ s(temp_c) + bottom_type + s(depth_m) + s(lon, lat, k = 12)

Parametric coefficients:

 Estimate Std. Error z value Pr(>|z|) 

(Intercept) 2.92273 0.02069 141.234 <2e-16 ***

bottom_type: Medium to coarse sand -0.42173 0.02901 -14.538 <2e-16 ***

bottom_type: Soft sediment -0.56414 0.06212 -9.081 <2e-16 ***

bottom_type: Transition zone 0.62576 0.03403 18.386 <2e-16 ***

Approximate significance of smooth terms:

 edf Ref.df Chi.sq p-value 

s(temp_c) 8.719 8.965 5196 <2e-16 ***

s(depth_m) 8.957 8.999 591 <2e-16 ***

s(lon,lat) 10.671 10.979 1375 <2e-16 ***

---

R-sq.(adj) = 0.556 Deviance explained = 61.8%

UBRE = 7.6194 Scale est. = 1 n = 857

___________________________________________________________________________
24

-71.2 -71.1 -71.0 -70.9

41.10 41.20

Longitude

Latitude

5 10 15 20

-3 -2 -1 0 1

Bottom Temperature (C)

Effect on lobste 

30 35 40

-3 -2 -1 0 1

Depth (m)

Effect on lobste 

Figure 17. Results of the Generalized Additive Model fit to lobster abundance per 

trawl in 2014 and 2015. The subplots show the linear predictors (partial effects) 

of bottom temperature (oC), depth (m), latitude (N) and longitude (E). The rug 

plots at the bottom of each subplot show the values of the predictor variables. 

7. Bycatch Species

A total of 39 different species were caught in the SNECVTS survey (Table 7). Besides the target 

species, lobster, the most numerous bycatch species were Jonah crab, rock crab, red hake, and 

black seabass. The spatial distributions of these species are plotted in Figs. 18-21. The Jonah 

crab data were analyzed separately because it was the most numerous bycatch species and 

because of the developing Jonah crab fishery.
25

Table 7. Total numbers of species other than lobsters caught in the SNECVTS survey. 

Total Abundance

Common Name Scientific Name 2014 2015

Jonah crab Cancer borealis 31,474 21,223

Rock crab Cancer irroratus 15,405 18,765

Red hake Urophycis chuss 3,133 1,795

Black seabass Centropristis striata 1,914 1,109

Cunner Tautogolabrus adspersus 779 359

Ocean pout Macrozoarces americanus 288 376

Conger eel Conger oceanicus 294 289

Scup Stenotomus chrysops 264 115

Sea raven Hemitripterus americanus 48 165

Longhon sculpin Myoxocephalus octodecemspinosus 60 63

Hermit crab Pagurus spp. 71 23

Moon snail Polinices heros 57 12

Atlantic cod Gadus morhua 20 23

Spotted hake Urophycis regia 6 2

Waved welk Buccinum undatum 4 4

Spider crab Libinia emarginata 5 2

Sea scallop Placopecten magellanicus 2 4

Starfish Asterias spp. 5 0

Skate (egg case) Leucoraja spp. 3 1

Spiny dogfish Squalus acanthias 2 2

Haddock Melanogrammus aeglefinus 3 0

Filefish Monacanthidae 2 1

Lions mane jellyfish Cyanea capillata 1 2

Smooth dogfish Mustelus canis 1 2

Butterfish Peprilus triacanthus 2 0

Sea robin Prionotus spp. 2 0

Yellowtail flounder Pleuronectes ferruginea 2 0

Ameican eel Anguilla rostrata 1 1

Pollock Pollachius virens 1 0

Snowy grouper Epinephelus niveatus 1 0

Speckled barrelfish Hyperoglyphe perciformis 1 0

Surfclam Spisula solidissima 1 0

Tilefish Lopholatililus chamaeleonticeps 1 0

Winter flounder Pseudopleuronectes americanus 1 0

American shad Alosa sapidissima 0 1

Mahogany clam Arctica islandica 0 1

Toadfish Opsanus tau 0 1

Triggerfish Balistes capriscus 0 1
26

Figure 18. Jonah crab, Cancer borealis, abundance was highest in the central blocks of the 

lease area. This abundance pattern was consistent between 2014 and 2015.

Figure 19. Rock crabs Cancer irroratus, were generally abundant throughout the lease-block 

area, with no clear spatial pattern or differences in abundance between 2014 and 2015. 
27

Figure 20. Red hake, Urophysis chuss, was more abundant in the southern blocks of the lease 

area (aliquots 12-24). Ovearall abundance was lower in 2015 than in 2014.

Figure 21. Black seabass, Centropristis striata, abundance was highest in the most northern 

and most southern aliquots, with lower abundance in between. Overall abundance was lower in 

2015 than in 2014.
28

7.1 Jonah crabs

Jonah crab catches were generally higher toward central longitudes of the lease block area (Fig.

18). In 2014 the highest catches came from aliquots 6 and 14, which are located in the eastern 

and south-central regions of the lease block area, respectively (Table 3). High catches for 2014 

also came from aliquots 2, 21 and 22. In 2015 the highest Jonah crab catches were in aliquots 25, 

29 and 33. Aliquots 25 and 29 are located in the north-central region of the lease block area, and 

aliquot 33 is located centrally. High catches for 2015 also came from aliquots 26, 28, 30 and 34. 

Jonah crab catches were highest in the month of September in both study years, followed by 

October (Table 8). Overall, Jonah crab catches were lowest in the months of May and June. The 

proportion of females was highest in catches in September and October and lowest in the months 

of June and July. Variations in total catch after May appear to be due largely to the variation in 

catches of females throughout the sampling season; catches of males were relatively consistent 

between months when compared to catches of females from May through October. Male Jonah 

crabs ranged in size from 40 mm to 191 mm, and females were between 49.1 mm and 188.8 mm. 

The mean carapace width of females (104 mm) was lower than for males (117 mm), which is 

consistent with the biology of the species (Fig. 22). 

Table 8. Total catch, and proportional catch by sex of Jonah crabs in 2014 and 2015. Total 

numbers of males and females by month were calculated by multiplying the total catch by sex 

proportion in the subset of measured crabs.

2014 2015

Month

Total 

Catch

Proportion 

Females Females Males

Total 

Catch

Proportion 

Females Females Males

May 1255 0.29 364 891 410 0.35 144 267

June 3816 0.10 382 3434 1847 0.16 304 1551

July 4371 0.08 350 4021 2897 0.08 232 2665

August 5194 0.44 2285 2909 2844 0.40 1138 1706

September 11091 0.56 6211 4880 8455 0.71 6003 2452

October 5747 0.54 3103 2644 4780 0.64 3059 1721

Total 31,474 12,695 18,779 21233 10,871 10,362

The fluctuations in female catches may be due to a change in behavioral patterns throughout the 

reproductive cycle. Observations of ovigerous females in this study found the highest proportion 

of females with eggs in May, with progressively decreasing proportions through October. This 

may be a cause for the reduced catches of females in spring and early summer months; sexspecific migration and behavioral changes associated with the reproductive cycle have been 

postulated as causes for differential catches of male and female Jonah crabs (Wenner et al. 

1992). Aggregating and burying behavior by ovigerous females has been observed in a related 

Cancer crab species (Rasmuson 2013), and low catchability of ovigerous females has been well 

documented in Cancer borealis and other cogeneric crabs (Krouse 1980, Ungfors 2007).
29

Figure 22. Length-frequency distributions of Jonah crabs by year and month. Dark bars are 

females and light bars are males. 

A generalized additive model was fitted to Jonah crab abundance, using smooth functions of 

predictor variables to predict Jonah crab catches by aliquot and date. Year and bottom type were 

entered as factors. The following variables were fitted with spline functions: temperature, depth, 

latitude, and longitude. Latitude and longitude were explored as interactive variables to explain 
30

geographic variation not explained by the other available predictor variables; in the interactive 

term between latitude and longitude, the number of knots was constrained to 12.

All independent variables were found to be significant in the chosen model, which explained 

57.5% of the variance in Jonah crab counts (Table 9). The year coefficient for 2015 is measured 

relative to 2014, and all habitat coefficients are measured relative to boulders on sand. Thus, 

Jonah crab abundance per trawl is ranked from highest to lowest according to the following 

bottom types, respectively: soft sediment, medium to coarse sand, boulders on sand, and 

transition zone. Interaction between latitude and longitude indicates a higher abundance of Jonah 

crabs in the northwest, northeast and south-central regions of the lease area, with lowest 

abundances in the southeast and southwest corners of the lease area (Fig. 23). Jonah crab 

abundance exhibits an increasing trend with temperature until ~ 15 °C, after which it appears to 

decline with increasing temperature. Catches were generally higher in 2014 than in 2015. Jonah 

crab catch increases with depth, though this relationship is not as strong as that of other 

variables. This may be due to the relatively small range of aliquot depths, or the depth to 

abundance relationship may be confounded by variables not investigated in this study.

Table 9. Generalized additive model fit to the abundance of Jonah crabs in 2014 and 

2015. A poisson model with a log link function was specified because the data are 

counts per trawl. 

Significance codes: *** < 0.001, ** < 0.01, * < 0.05.

_________________________________________________________________________

Formula:

jonah_crab ~ s(lon, lat, k = 12) + bottom_type + s(temp) + s(depth) + year

Parametric coefficients:

 Estimate Std. Error z value Pr(>|z|) 

(Intercept) 847.25967 23.17032 36.567 < 2e-16 ***

bottom_typeMedium to coarse sand 0.24176 0.01725 14.014 < 2e-16 ***

bottom_typeSoft sediment 0.35454 0.03502 10.123 < 2e-16 ***

bottom_typeTransition zone -0.18024 0.02945 -6.119 9.4e-10 ***

year -0.41877 0.01150 -36.405 < 2e-16 ***

---

Approximate significance of smooth terms:

 edf Ref.df Chi.sq p-value 

s(lon,lat) 10.966 11.000 3404 <2e-16 ***

s(temp) 8.596 8.936 13226 <2e-16 ***

s(depth) 8.976 9.000 1312 <2e-16 ***

---

R-sq.(adj) = 0.469 Deviance explained = 57.5%

UBRE = 23.228 Scale est. = 1 n = 857

__________________________________________________________________________
31

Figure 23. Results of the Generalized Additive Model fit to Jonah crab abundance per trawl 

in 2014 and 2015. The subplots show the linear predictors (partial effects) of bottom 

temperature (°C), depth (m), latitude (N), and longitude (E). The rug plots at the bottom of 

each subplot show the values of the predictor variables. 
32

8. Pilot Tagging Study 

A pilot tagging study was initiated in 2015, to begin to evaluate the movement of lobsters in and 

around the RI/MA lease area and the probability that the same lobsters are captured multiple 

times. Lobsters were tagged with individually numbered cable ties, attached around the “elbow” 

of the claw (Fig. 24). The tag is expected to remain on the lobster until it molts. We chose to tag 

on 14 August 2015 because by this date many lobsters have just molted. A total of 300 lobsters 

were tagged—100 on each vessel, distributed more-or-less evenly among aliquots (e.g. 12 per 

aliquot, depending on numbers caught). All sizes of lobsters were tagged. Lobsters with shell 

disease were not tagged, as these old-shell lobsters are more likely to molt and shed the tag.

Figure 24. Lobster tagged on 14 August 2015.

Thirty-nine recaptures have been reported, both by SNECVTS samplers and by other lobstermen 

(Appendix 4). Three of these 39 were double recaptures. This 13% recapture rate is 

encouraging, considering there was no advertising or incentive for reporting tags—just a phone 
33

number on the tag. Most of the recaptures occurred within two months of tagging (Fig. 25). 

These results are consistent with previous tagging studies, in which most recaptures occurred in 

the first few months near where the lobsters were tagged (Campbell & Stasko 1985). Four 

tagged lobsters were caught in November/December and three in June/July 2016. The most 

recent tag recaptures was on 17 August 2016, showing that the tags can remain on lobster for 

over a year.

Distance traveled (km

0 20 40 60 80 100 140

0

2

4

6

8

10

Days at large

0 100 200 300

0

5

10

15

Velocity (km/day)

0 1 2 3 4

0

5

10

15

Frequency

Figure 25. Distance traveled by lobsters from the point of tagging to the point 

of recapture, days between tagging and recapture and estimated velocity.

Most recaptures were in the vicinity of the lease block area (Figs. 25 and 26). The majority of 

lobsters traveled less than 25 km; 10 of these traveled less than 1km. There was no obvious 
34

direction of travel, except that few lobsters moved in a northerly direction. Four lobsters 

traveled over 120 km to the edge of the continental shelf where they were caught by offshore 

lobstermen (Figs. 25 and 27). Four of these lobsters were large females (>85 mm) and one was 

male (78 mm). One of these four lobsters travelled 123 km in 28 days, which implies a velocity 

over 4 km per day.

Previous tagging studies indicate that mature lobsters travel considerably farther than juveniles 

(Campbell & Stasko 1985, Campbell 1986). Long-distance migration (>100km) has been 

reported, including lobsters that make excursions of 10-400 km, returning to the area of initial 

tagging after 10 to 14 months (Pezzack & Duggan 1986). These long excursions are thought to 

be part of the temperature-mediated, seasonal migration of American lobster.

This pilot tagging study demonstrated the feasibility of using numbered cable ties to mark 

lobsters. The 13% recapture rate is high compared with other tagging studies and could be 

increased with publicity and incentives for reporting. About two thirds of the recaptures were 

made inside the lease block area. Although these recaptures are not corrected for sampling 

effort, they do indicate a residence time of months within the lease block area.

Figure 26. Tagging and recapture locations of lobsters tagged on 14 August 2015 and 

recaptured in the vicinity of the RI/MA Lease Area.
35

Figure 27. Tagging and recapture locations of all lobsters tagged on 14 August 2015.
36

9. Conclusions

9.1 Implications for siting and monitoring impacts of offshore wind energy 

development

This project documented a healthy population of American lobster on Cox Ledge in the RI/MA 

wind energy area. A broad size range of lobsters was sampled, from 40-mm juveniles to large, 

ovigerous females. The occurrence of small lobsters indicates recruitment to this area. The 

incidence of shell disease was low compared with shallower, estuarine areas. Given the adverse 

environmental conditions (high summer temperature, low dissolved oxygen) in estuaries, 

protection of the offshore component is needed to conserve the SNE lobster population (Wahle et 

al. 2015).

Survey results were consistent between the two years of the survey. Lobster abundance was 

consistently higher on the eastern side of the lease area. High density areas included aliquots 

9,10,11, and 35 and aliquots 16-19 and 40-43. In general, these sites are relatively shallow with 

a bottom type consisting of boulders or a transition from boulders to medium sand. These 

aliquots are found in BOEM lease blocks 6918, 6919, and 6968-6971. High lobster densities 

were also measured at aliquots 2 and 26 at the northern edge of the lease area. These two 

aliquots were deeper (37-40 m) with soft sediments. They are in BOEM lease block 6817.

Table 10. Comparison of catch per trap between SNECVTS and the RI DEM ventless trap 

survey, which is conducted in RI state waters. State data courtesy of Michael McManus, RI 

DEM.

RIDEM Standard trap Ventless trap

Year June July August September June July August September

2006 NA 1.56 1.40 1.12 NA 10.03 9.76 8.39

2007 2.18 3.18 1.90 NA 6.56 14.34 10.00 NA

2008 2.77 3.06 2.01 NA 10.22 14.58 9.85 NA

2009 NA 2.06 1.28 1.05 NA 13.12 7.19 5.27

2010 NA 1.99 1.65 0.86 NA 7.49 7.46 4.05

2011 NA 1.82 1.71 2.17 NA 7.69 6.74 7.01

2012 2.09 1.50 1.08 NA 9.12 7.59 6.34 NA

2013 1.38 1.32 1.11 NA 4.63 4.93 3.69 NA

2014 0.62 1.11 1.20 NA 3.07 5.02 5.58 NA

2015 0.91 1.62 1.43 NA 3.96 6.36 5.55 NA

SNECVTS Standard trap Ventless trap

2014 0.78 1.49 1.78 1.49 1.31 4.27 6.28 4.94

2015 0.48 0.94 1.90 1.78 0.62 1.89 5.38 5.32
37

Lobster catch rates were consistent with those from the corresponding months and years in the 

RI DEM ventless trap survey. This comparison confirms the importance of the RI/MA Lease 

Area as lobster habitat, compared with inshore areas.

Despite the patchy habitat and sampling variability, a generalized additive model explained 62% 

of the deviance in lobster catches. On average, lobsters prefer boulder habitat and the transition 

from boulders to sand, compared with uniform sand and soft sediments (Cooper and Uzmann 

1980). These preferred habitat types are available throughout the study area. Lobster abundance 

increased with depth, but this was a weak effect given the limited depth range of the study area.

Bottom temperature was the strongest predictor of lobster catches, which increased up to about 

14 oC and were fairly constant above this threshold. Summer bottom-water temperatures are 

within the optimal temperature range of 12-18 oC. Temperatures above 20 oF, which are known 

to stress lobsters, occurred only in aliquots 23 and 24 at the end of September 2014. Lobster 

catches increased throughout the summer, peaking in August and September, before declining in 

October. This pattern is consistent with the paradigm of a temperature-mediated, seasonal, 

onshore-offshore migration. The pilot tagging study demonstrated that most lobsters remained in 

the lease block area for several months. A few undertook long migrations to the edge of the 

continental shelf, which is consistent with known seasonal migration patterns of the American 

lobster.

Jonah crab, Cancer borealis, was the most numerous species caught in the survey. Jonah crabs 

ranged in size from 40 to 190 mm carapace with, with most falling between 60 and 160 mm. 

Jonah crabs were most abundant in central longitudes of the lease blocks. Apart from aliquots 2 

and 26 in the north, the preferred habitat of Jonah crabs did not intersect with that of lobsters. 

According to the generalized additive model, Jonah crabs prefer soft and sand substrates 

compared with boulders. As with lobsters, there was a strong effect of temperature on Jonah 

crab catch rates. Jonah crab abundance increased throughout the summer, peaking in September. 

This seasonal pattern was driven mostly by females, which were rare in spring and dominant in 

early fall. 

9.2 Recommendations for Future Research

Continuing efforts to evaluate the distribution and habitat use of lobsters and Jonah crabs in areas 

of wind energy development are essential (Petruny-Parker et al. 2015). The SNECVTS project 

established a cooperative survey protocol for monitoring the effects of offshore wind-energy 

development on lobster and crab populations. The study established a pre-construction baseline 

for lobster and Jonah crab populations to enable assessment of possible impacts of development. 

This survey should be continued, in some form, to provide a continuous time series of 

abundance, as development progresses. The survey design could be streamlined to provide cost 

efficiencies. Variables to consider include the number of months sampled and the number of 

sampling trips per month. For example, by reducing the number of sampling trips per month 

from three to two, sampling could be extended to include April and November. The number and 

identity of lease blocks to be surveyed could also be modified, based on offshore wind 

construction plans for the lease area, to focus on those lease blocks where development is most 

likely to occur and to identify appropriate control stations. The scope of coverage could also 
38

possibly be expanded to include portions of the areas leased offshore Massachusetts (leases 

OCS-A 0500 and OCS-A 0501), but this would require cooperation with larger fishing vessels. 

As part of the ventless trap survey, a more intensive tagging study should be conducted to 

determine the seasonal movement patterns and habitat use by lobsters. Lobsters are thought to 

migrate offshore in the fall and onshore in spring (Fogarty 1995), but recent observations 

challenge this paradigm. With the last lobster tagging study in the Southern New England region 

conducted over 20 years ago (focused on the North Cape oil spill), there is an urgent need to 

assess current lobster movement patterns and the potential impacts of wind energy development 

in this region. An intensive tagging study would involve monthly tagging of 500 lobsters across 

the study site. Recoveries would be made by the sea samplers and reported by commercial 

lobstermen. Outreach and incentive programs will need to be developed to encourage tag 

reporting. 

Encouraging results were obtained using individually numbered zip ties as tags, which are 

inexpensive, easy to apply, and remain on the lobster until it molts. Other types of tags could be 

considered, including spherion tags, which are retained when a lobster molts and have been used 

in previous lobster tagging studies (Campbell & Stasko 1985, Campbell 1986, Pezzak and 

Duggan 1986). Conventional tagging provides only the release and recapture locations, between 

which movement is inferred. In addition to conventional tagging, acoustic telemetry could 

provide more fine-scale data on lobster movement. Acoustic tagging studies have been 

performed on American lobster in Canadian waters, as well as spiny lobsters, the European 

lobster, and the Norway lobster. This work would involve affixing ~100 acoustic tags to newshell lobsters captured within the study area. Fixed receivers could be deployed on lobster 

sampling gear in areas of high lobster density to track onshore-offshore movements. 
39

References Cited

Atlantic States Marine Fisheries Commission (ASMFC). 2009. Stock Assessment Report No. 09-

01.

Atlantic States Marine Fisheries Commission (ASMFC). 2010. Recruitment failure in the 

southern New England lobster stock. Prepared by the American Lobster Technical 

Committee, Atlantic State Marine Fisheries Commission, 58 pp.

Atlantic States Marine Fisheries Commission (ASMFC). 2015. Stock assessment overview: 

American lobster. www.smfc.org/species/american-lobster. 

Campbell, A. 1986. Migratory movements of ovigerous lobsters, Homarus americanus, tagged 

off Grand Manan, eastern Canada. Can. J. Fish. Aquat. Sci. 43:2197-2205.

Campbell, A. and A.B. Stasko. 1985. Movements of tagged lobsters, Homarus americanus, 

tagged off southwestern Nova Scotia. Can. J. Fish. Aquat. Sci. 42:229-238.

Castro, K.M. and T.E. Angell. 2000. Prevalence and progression of shell disease in American 

lobster, Homarus americanus, from Rhode Island waters and offshore canyons. Journal of 

Shellfish Research 19:691-700. 

Cooper, R.H. and J.R. Uzmann 1980. Ecology of juvenile and adult Homarus. Pages 97-142 in 

J.S. Cobb and B.F. Phillips, eds. Biology and management of lobsters, Vol II. Academic 

Press, New York.

Crowder, L. and E. Norse. 2008. Essential ecological insights for marine ecosystem-based 

management and marine spatial planning. Marine Policy 32 (5): 772-778.

Fogarty, M.J. 1995. Fisheries, populations, and management. In The biology of the American 

lobster, Homarus americanus. Edited by J. Factor. Academic Press, New York, NY.

Foley, M.M., Halpern, B.S., Micheli, F., Armsby, M.H., Caldwell, M.R., Crain, C.R., Prahler, E., 

Rohr, N., Sivas, D.,Beck, M.W., Carr, M.H., Crowder, L.B., Duffy, J.E., Hacker, S.D., 

McLeod, K.L., Palumbi, S.R., Peterson, C.H., Regan, H.M., Ruckelshaus, M.H., 

Sandifer, P.A., and R.S. Steneck. 2010. Guiding ecological principles for marine spatial 

planning. Marine Policy 35(5): 955-966.

Hasbrouck, E.C, Scotti, J., Stent, J. and Gerbino, K. 2011. Rhode Island commercial fishing and

seafood industries: The development of an industry profile. 124 pp.

Krouse, J.S. 1980. Distribution and catch composition of Jonah crab, Cancer borealis, and rock 

crab, Cancer irroratus, near Boothbay Harbor, Maine. Maine Department of Marine 

Resources Fishery Bulletin 77(3):685-693.

LaFrance, M., E. Shumchenia, J. King, R. Pockalny, B. Oakley, S. Pratt, J. Boothroyd. 2010. 

Benthic habitat distribution and subsurface geology selected sites from the Rhode Island 

Special Area Management Study Area. University of Rhode Island Technical Report 
40

(Technical Report 4). Retrieved from: 

http://seagrant.gso.uri.edu/oceansamp/pdf/appendix/04-LaFrance_et_al_SAMPreport.pdf

LaFrance, M., J.W. King, B.A. Oakley and S. Pratt. 2014. A comparison of top-down and 

bottom-up approaches to benthic habitat mapping to inform offshore wind energy 

development. Continental Shelf Research 83:24-44.

Malek, A.J., J.S. Collie, and J. Gartland. 2014. Fine-scale spatial patterns in the demersal fish 

and invertebrate community in a northwest Atlantic ecosystem. Est. Coast. Shelf Sci. 

147:1-10.

Massachusetts Division of Marine Fisheries (MADMF). 2010. Massachusetts Lobster Fishery 

Statistics. Boston, MA. 

Olsen, S.B., J.H. McCann and G. Fugate. 2014. The State of Rhode Island’s pioneering marine 

spatial plan. Marine Policy 45:26-38.

Petruny-Parker, M., Malek, A., Long, M., Spencer, D., Mattera, R., Hasbrouck, E., Scotti, J., 

Gerbino, K., Wilson, J. 2015. Identifying information needs and approaches for assessing 

potential impacts of offshore wind farm development on fisheries resources in the 

Northeast Region. U.S. Dept. of the Interior, Bureau of Ocean Energy Management, 

Office of Renewable Energy Programs, Herndon, VA. OCS Study BOEM 2015-037. 79 

pp.

Pezzack, D.S. and D.R. Duggan. 1986. Evidence of migration and homing of lobsters (Homarus 

americanus) on the Scotian Shelf. Can. J. Fish. Aquat. Sci. 43:2206-2211.

Rasmuson, L.K. 2013. The biology, ecology and fishery of the Dungeness crab, Cancer 

magister. Advances in Marine Biology 65: 95-148.

Schmitt, R.J. and Craig W. Osenberg. 1996. Detecting ecological impacts: concepts and 

applications in coastal habitats. Academic Press. San Diego, California. 401 p.

Ungfors, A. 2007. Sexual maturity of the edible crab (Cancer pagurus) in the Skagerrak and the 

Kattegat, based on reproductive and morphometric characters. ICES Journal of Marine 

Science 64:318-327.

Wahle, R.A. Lanny Dellinger, S. Olszewski, and P. Jekielek. 2015. American lobster nurseries of 

southern New England receding in the face of climate change. ICES Journal of Marine 

Science 72(supp_1):i69-i78, doi:10.1093/icesjms/fsv093.

Wenner, E.L., C.A. Barans, and G.F. Ulrich. 1992. Population structure and habitat of Jonah 

crab, Cancer borealis, Stimpson 1859, on the continental slope off the United States. 

Journal of Shellfish Research 11(1):95-103.

Wentworth, C.K. 1922. A scale of grade and class terms for clastic sediments. The Journal of 

Geology 30(5):377-392.
41

Appendix 1. List of project personnel

Name Affiliation Role

Jeremy Collie URI/Graduate School of Oceanography Principal Investigator

John King URI/Graduate School of Oceanography Co-principal Investigator

Lanny Dellinger Captain, F/V Megan & Kelsey Vessel 1

Greg Mataronas Captain, F/V Cailyn Grace Vessel 3

Brian Thibeault Captain, F/V Ashley Ann Vessel 2

Bill McElroy Captain, F/V Ellen June Backup fishing vessel

Anna Malek URI/Graduate School of Oceanography Field Coordinator

Monique LaFrance 

Bartley

URI/Graduate School of Oceanography Benthic habitat analysis

Corinne Truesdale URI/Graduate School of Oceanography Lobster and Jonah crab data analysis

David Taylor Roger Williams University Supervisor of RWU undergraduates

Saroj Mohanty URI Engineering student Designed Lobster Tracks software

Alyssa Gavlik URI Graduate Assistant Sea Sampler

Chip Heil URI Research Associate Lead Sea Sampler

Dan Denaro URI Gradaute Lead Sea Sampler

Matthew Griffin Roger Williams University Lead Sea Sampler

Nathan Andrews URI Graduate Assistant Sea Sampler

Nick Calabrase Roger Williams University Assistant Sea Sampler

Oliver Bender URI Graduate Assistant Sea Sampler
42

Appendix 2. Grab samples collected for ground-truthing the acoustic 

mapping of lobster sampling sites. Locations of the grab samples are listed by 

Aliquot. The final column is a visual description of the grab sample from the field notes.

Aliquot Latitude Longitude Grab 

Sample # Date Description

1 -71.146 41.226 LS43 11/18/15 Full, fine-medium sand, shells, amphipod 

1 -71.148 41.223 LS44 11/18/15 Fine-medium tan sand, some shell hash, tubes

1 -71.149 41.221 LS45 11/18/15 fine-medium sand tan, tubes

2 -71.088 41.229 LS40 11/18/15 Medium sand, some amphipods, tubes

2 -71.093 41.226 LS41 11/18/15 very fine sand, mud, tubes

2 -71.092 41.222 LS42 11/18/15 Fine-medium sand, large 4-5 inch quahog clams, full

3 -71.203 41.195 LS1 8/19/2015 Full grab; medium sand, tubes, shrimp

3 -71.204 41.193 LS2 8/19/2015 1/2 grab, medium brown sand, tubes

3 -71.205 41.191 LS3 8/19/2015 Medium sand, brown, tubes, shells

4 -71.140 41.184 LS34 8/19/2015 Full, piece of sand dollar, medium sand, amphipod tubes

4 -71.144 41.182 LS35 8/19/2015 Full, tan medium sand, tubesm amph. Shell hash

4 -71.145 41.180 LS36 8/19/2015 Tan, medium sand, tubes, amph. Shell hash

5 -71.119 41.186 LS37 8/19/2015 full, medium sand, tubes, amph

5 -71.120 41.184 LS38 8/19/2015 full tan medium-fione sand, amph tubes

5 -71.121 41.181 LS39 8/19/2015 Full coarse sand, reddish quahog (3 inches), shell hash

7 -71.217 41.172 LS4 8/19/2015 Coarse brown sand, some tubes, shall hash, full grab

7 -71.218 41.170 LS5 8/19/2015 Medium to coarse brown sand; sand dollar, shell hash

7 -71.219 41.168 LS6 8/19/2015 Medium to coarse brown sand; sand dollar, shell hash

8 -71.145 41.161 LS31 8/19/2015 Full, finer sand w/ tubes + amph. Shell hash

8 -71.146 41.159 LS32 8/19/2015 3/4 full, slightly coarser sand, tubes, shell hash, amph.

8 -71.146 41.157 LS33 8/19/2015 Full, medium coarse sand, tubes, shell hash

9 -71.085 41.163 LS46 8/19/2015 Full, fine-med sand, tubes, amph. Small shell hash

9 -71.089 41.162 LS47 8/19/2015 1/2 full, coarser sand-pebbles, shell hash

9 -71.091 41.160 LS48 8/19/2015 Very little sample, recovered boulders

10 -71.044 41.173 LS49 6/27/2016 Full grab, sand, shells, pebbles

10 -71.044 41.170 LS50 6/27/2016 Full grab, sand, silty, shells, cobbles

10 -71.046 41.168 LS51 6/27/2016 Full grab, sand, shells, pebbles

11 -70.957 41.176 LS52 6/27/2016 1/2 full, sand, rocks, shell hash

11 -70.960 41.174 LS53 6/27/2016 mostly rocks, very little sediment

11 -70.960 41.171 LS54 6/27/2016 1/4 full

12 -71.240 41.117 LS10 6/27/2016 1/3 grab, very coarse sand, gravel, some cobbles

12 -71.240 41.115 LS11 6/27/2016 Coarse to very coarse sand, some gravel; few shells

12 -71.238 41.113 LS12 6/27/2016 Coarse to very coarse brown sand, 1/4 full grab

13 -71.217 41.100 LS13 1/7/2016 Full, fine sand, tubes

13 -71.215 41.096 LS14 1/7/2016 1/4 Full of rocks; lots of rocks, 5 inch rocks

13 -71.215 41.098 LS15 1/7/2016 3/4 Full, tubes, brown fine sand

14 -71.125 41.108 LS25 1/7/2016 full extrafine silt/clay material, amph. Shell hash
43

14 -71.126 41.105 LS26 1/7/2016 3/4 full, lots of tubes/amph, fine sand

14 -71.124 41.103 LS27 1/7/2016 Full, medium sand, brown tubes, amph

15 -71.112 41.119 LS28 6/28/2016 Full, coarse sand, pebbles, shell hash

15 -71.112 41.116 LS29 6/28/2016 1/2 full, sand, pebbles, shell hash

15 -71.112 41.114 LS30 1/7/2016 1/8-1/4 full, gravel, sand-gravel

15 -71.113 41.114 LS30 6/28/2016 1/4 full, rocks, shells

16 -71.026 41.123 LS64 6/28/2016 1/4 full, sand, rocks, cobbles

16 -71.029 41.122 LS65 6/28/2016 Full grab, sand

16 -71.031 41.118 LS66 6/28/2016 1/2 full, sand

18 -70.941 41.101 LS55 6/28/2016 Full grab, sand

18 -70.940 41.097 LS56 6/28/2015 3/4 full, sand, few shells

18 -70.943 41.099 LS57 6/28/2016 Full grab, sand

20 -71.200 41.086 LS16 1/7/2016 1/4 full, coarse sand, cobbles. 1 lg rock

20 -71.198 41.082 LS17 1/7/2016 Full, lots of rocks, med sand-coarse sand, shell hash

20 -71.197 41.080 LS18 1/7/2016 Rocks, 3/4 full, variation in grain size, gravel, coarse sand

21 -71.123 41.065 LS19 1/7/2016 Full, fine sand, tubesm, some shell hash

21 -71.122 41.068 LS20 1/7/2016 rocks in jaws, 1/8 full, shell frag, coarse sand, rocks

21 -71.120 41.074 LS21 1/7/2016 3/4 full, medium sand, rocks, pebbles, gravel

22 -71.095 41.075 LS22 1/7/2016 1/4 full, rocks, medium sand, coarse, large cobbles

22 -71.101 41.079 LS23 1/7/2016 coarse sand w/ small cobbles, pebbles, shell hash

22 -71.099 41.077 LS24 1/7/2016 1/8 full, fine sand, worms, some cobbles (pebbles)

23 -71.040 41.082 LS61 6/28/2016 Full grab, sand

23 -71.039 41.085 LS62 6/28/2016 Full grab, sand

23 -71.038 41.088 LS63 6/28/2016 3/4 full, sand, some shell hash

24 -70.969 41.087 LS58 6/28/2016 Full grab, sand, some shell hash

24 -70.971 41.089 LS59 6/28/2016 3/4 full, sand, some shell hash

24 -70.970 41.091 LS60 6/28/2016 3/4 full, sand, some shell hash, big quahog

25 -71.170 41.218 LS101 11/18/2015 Fine sand, medium tubes

25 -71.170 41.216 LS102 11/18/2015 medium brown sand, with tubes, full grab

25 -71.172 41.214 LS103 11/18/2015 mud - fine sand, tubes (tan-brown), full grab

26 -71.074 41.228 LS143 11/18/2015 Fine-medium sand, tubes, amph. Shell hash

26 -71.075 41.226 LS144 11/18/2015 Fine sands, amph shell hash

26 -71.075 41.224 LS145 11/18/2015 Lots of amph, fine sand, shell hash, tan sand

27 -71.188 41.190 LS104 8/19/2015 Coarse to very coarse sand, brown, snails

27 -71.190 41.188 LS105 8/19/2015 Full grab; coarse sand, brown

27 -71.191 41.186 LS106 8/19/2015 Medium to coarse sand, brown to dark brown

28 -71.123 41.194 LS140 8/19/2015 Full, worms, little tubes, (not a lot) amph, fine-med sand

28 -71.124 41.192 LS141 8/19/2015 Full, fine-medium sand, tubes, worms, some shell hash

28 -71.126 41.191 LS142 8/19/2015 Full, fine-med sand tan, small hash, amph. tubes

29 -71.076 41.216 LS146 8/19/2015 3/4 full, medium sand, shell hash, amph

29 -71.075 41.215 LS147 8/19/2015 Full, fine-medium sand, amph shells hash, tubes

29 -71.077 41.213 LS148 8/19/2015 Shell hash, fine-medium sand, some amph tubes

31 -71.183 41.170 LS107 8/19/2015 Brown to dark brown, medium sandy; shell hash, shrimp
44

31 -71.185 41.168 LS108 8/19/2015 Brown medium sand; shell hash, quahog

31 -71.187 41.167 LS109 8/19/2015 Brown medium sand; shell hash

32 -71.122 41.151 LS134 8/19/2015 1/4 very little samplke, cobbles/pebbles, coarse sand

32 -71.123 41.149 LS135 8/19/2015 3/4 full, gravel, coarse sand, amph.

32 -71.123 41.148 LS136 8/19/2015 3/4 full, medium sand, worms, shell hash, amph.

33 -71.116 41.153 LS137 8/19/2015 Full grab, med sand, shell hash, sand dollar

33 -71.115 41.149 LS138 8/19/2015 Full, med sand, sand dollars, worms (large)

33 -71.114 41.152 LS139 8/19/2015 Full, fine-med sand, amph, tubes, shell hash

34 -71.027 41.171 LS149 6/27/2016 Full grab, sand

34 -71.029 41.170 LS150 6/27/2016 Full grab, sand

34 -71.031 41.168 LS151 6/27/2016 Full grab, sand

35 -70.984 41.161 LS152 6/27/2016 3/4 full, sand, shell hash

35 -70.986 41.160 LS153 6/27/2016 Full grab, sand

35 -70.987 41.158 LS154 6/27/2016 Full grab, sand

36 -71.251 41.126 LS110 6/27/2016 1/2 grab, very coarse sand to gravel, brown

36 -71.253 41.124 LS111 6/27/2016 Coarse brown sand, some shells and tubes, some cobble

36 -71.252 41.122 LS112 6/27/2016 Coarse sand & gravel up to ~5cm, not as coarse as LS111

37 -71.195 41.121 LS113 1/7/2016 Fine sand,w/ cobble, 1/4 full

37 -71.196 41.123 LS114 1/7/2016 3/4 full, sand -fine, tan, tubes

37 -71.193 41.125 LS115 1/7/2016 1/2 full, coarse sand, small gravel

38 -71.168 41.104 LS116 1/7/2016 3/4 full, tubes, coarse sand, gravel, worms

38 -71.169 41.102 LS117 1/7/2016 3/4 full, fine sand with tubes, some shell hash

38 -71.170 41.100 LS118 1/7/2016 1/2 full, small cobbles and very coarse sand

39 -71.081 41.092 LS125 1/7/2016 1/4 full, medium sand, shells, rocks, pebbles ~3inches

39 -71.080 41.090 LS126 1/7/2016 full, fine sand, with tubes and amph

39 -71.082 41.094 LS127 1/7/2016 4in rock, fine sand w/ tubes amph. Very small pebbles

40 -71.010 41.098 LS167 6/28/2016 1/2 full, sand, pebbles, few cobbles

40 -71.012 41.097 LS168 6/28/2016 1/2 full, sand, pebbles

40 -71.012 41.096 LS169 6/28/2016 3/4 full, sand

42 -70.930 41.129 LS158 6/28/2016 Full grab, sand, pebbles, shells

42 -70.930 41.128 LS159 6/28/2016 Full grab, sand

42 -70.928 41.131 LS160 6/28/2016 1/4 full, sand, rocks

44 -71.178 41.083 LS119 1/7/2016 1/4 full of pebbles, tan sand

44 -71.179 41.080 LS120 1/7/2016 rocks in jaws, 3/4 full, coarse sand, gravel/small cobbles

44 -71.181 41.080 LS121 1/7/2016 3/4 Full, fine-medium brown sand, w/ tubes/amphipods

45 -71.141 41.086 LS122 1/7/2016 1/8 full, large rock, large shell

45 -71.144 41.083 LS123 1/7/2016 1/2 full, fine sand, gravel, shells, rocks

45 -71.144 41.081 LS124 1/7/2016 3/4 full, fine sand, shell hash, 3cm rock

46 -71.080 41.083 LS128 1/7/2016 rocks in jaws, medium sand w/ small pebbles

46 -71.079 41.084 LS129 1/7/2016 Full, medium sand, small pebbles, worm, 1-5in rock

46 -71.078 41.086 LS130 1/7/2016 1/2 full, medium sand, shell hash

47 -71.054 41.086 LS131 6/28/2016 Full grab, sand, some shell hash

47 -71.055 41.084 LS132 6/28/2016 1/2 full, sand
45

47 -71.056 41.083 LS133 6/28/2016 2/3 full, sand

48 -70.955 41.088 LS164 6/28/2016 Full grab, sand

48 -70.955 41.086 LS165 6/28/2016 Full grab, sand

48 -70.956 41.085 LS166 6/28/2016 Full grab, sand, few pebbles

17, 41 -70.950 41.117 LS161 6/28/2016 rock caught in jaws, very small sample

17, 41 -70.958 41.119 LS162 6/28/2016 3/4 full, sand, pebbles

17, 41 -70.956 41.120 LS163 6/28/2016 1/4 full, cobbles, pebbles, sand

19, 43 -70.858 41.129 LS155 6/27/2016 Full grab, sand

19, 43 -70.859 41.127 LS156 6/27/2016 Full grab, sand

19, 43 -70.860 41.124 LS157 6/27/2016 Full grab, sand

6, 30 -71.244 41.157 LS7 6/27/2016 Coarse brown to dark brown sand; shell hash

6, 30 -71.246 41.155 LS8 6/27/2016 Coarse, brown sand; some shell hash, tubes

6, 30 -71.247 41.153 LS9 6/27/2016 Coarse brown sand; some shells and tubes

Appendix 3. Coordinates of sampling locations, depth, and habitat 

classification

Year Aliquot Habitat Depth (m) N latitude W longitude

2014 1 Medium to coarse sand 37.5 41.221 71.140

2014 2 Soft sediment 40.8 41.222 71.083

2014 3 Medium to coarse sand 40.8 41.187 71.196

2014 4 Medium to coarse sand 37.2 41.177 71.137

2014 5 Medium to coarse sand 37.2 41.178 71.110

2014 6 Medium to coarse sand 42.4 41.154 71.238

2014 7 Medium to coarse sand 36.3 41.165 71.210

2014 8 Medium to coarse sand 35.1 41.155 71.138

2014 9 Transition zone 34.1 41.156 71.080

2014 10 Transition zone 34.1 41.168 71.038

2014 11 Boulders on sand 27.4 41.170 70.953

2014 12 Boulders on sand 33.2 41.111 71.236

2014 13 Boulders on sand 33.2 41.089 71.208

2014 14 Medium to coarse sand 38.7 41.102 71.122

2014 15 Boulders on sand 34.7 41.112 71.107

2014 16 Boulders on sand 34.7 41.114 71.022

2014 17 Boulders on sand 32.6 41.116 70.950

2014 18 Medium to coarse sand 36.0 41.095 70.936

2014 19 Transition zone 37.5 41.128 70.852

2014 20 Boulders on sand 33.5 41.079 71.193

2014 21 Boulders on sand 34.7 41.069 71.120

2014 22 Boulders on sand 33.5 41.069 71.092

2014 23 Medium to coarse sand 36.0 41.081 71.036

2014 24 Medium to coarse sand 35.4 41.082 70.963
46

2015 25 Soft sediment 43.0 41.242 71.127

2015 26 Soft sediment 37.2 41.253 71.098

2015 27 Medium to coarse sand 39.9 41.187 71.182

2015 28 Soft sediment 38.7 41.188 71.125

2015 29 Medium to coarse sand 35.7 41.211 71.068

2015 30 Medium to coarse sand 42.4 41.153 71.238

2015 31 Medium to coarse sand 39.3 41.165 71.181

2015 32 Boulders on sand 35.7 41.145 71.124

2015 33 Boulders on sand 34.4 41.145 71.109

2015 34 Medium to coarse sand 32.9 41.168 71.024

2015 35 Medium to coarse sand 34.1 41.158 70.981

2015 36 Boulders on sand 33.8 41.121 71.251

2015 37 Boulders on sand 31.4 41.122 71.194

2015 38 Medium to coarse sand 35.1 41.101 71.165

2015 39 Medium to coarse sand 33.8 41.092 71.079

2015 40 Medium to coarse sand 36.0 41.093 71.008

2015 41 Boulders on sand 32.6 41.115 70.951

2015 42 Transition zone 32.9 41.127 70.923

2015 43 Medium to coarse sand 37.5 41.128 70.851

2015 44 Medium to coarse sand 34.1 41.079 71.179

2015 45 Boulders on sand 34.7 41.080 71.136

2015 46 Boulders on sand 33.8 41.081 71.079

2015 47 Medium to coarse sand 35.7 41.081 71.050

2015 48 Medium to coarse sand 36.6 41.083 70.950
47

Appendix 4. Data from tagged and recaptured lobsters

Tag

number

Tagged 

latitude

Tagged

longitude

Recapture 

latitude

Recapture 

longitude

Distance 

Traveled 

(km)

Days at 

large Bearing

Travel rate 

(km/day)

1 41.0848 -71.1418 41.1017 -71.1674 2.857 26 -49 0.110

20 41.1245 -71.2519 39.9917 -70.9250 128.688 302 167 0.426

33 41.1245 -71.2519 41.1250 -71.2507 0.117 32 63 0.004

39 41.0921 -71.0807 41.0921 -71.0807 0.000 10 NA 0.000

43 41.0921 -71.0807 41.0800 -71.0500 2.908 6 118 0.485

58 41.1245 -71.2519 41.1245 -71.2519 0.000 5 NA 0.000

68 41.1246 -71.1936 41.2467 -71.3417 18.378 27 -42 0.681

69 41.1245 -71.2519 41.1245 -71.2519 0.000 10 NA 0.000

75 41.0822 -71.1784 41.0638 -71.1055 6.457 14 108 0.461

82 41.1246 -71.1936 41.0348 -71.2612 11.464 8 -150 1.433

90 41.0848 -71.1418 41.0224 -71.3817 21.320 123 -109 0.173

92 41.1555 -71.2432 41.1733 -71.2545 2.193 7 -26 0.313

105 41.2169 -71.1702 41.2169 -71.1702 0.000 35 NA 0.000

124 41.1656 -71.1847 41.2430 -71.0065 17.237 21 60 0.821

131 41.2236 -71.0741 41.2006 -70.9013 14.717 20 100 0.736

137 41.2123 -71.0757 41.1553 -71.0977 6.584 14 -164 0.470

142 41.2169 -71.1702 41.1508 -71.1858 7.448 9 -170 0.828

148 41.1873 -71.1888 41.0844 -71.0773 14.764 5 141 2.953

153 41.1873 -71.1888 41.0224 -71.1324 18.899 43 165 0.440

173 41.1912 -71.1248 41.2467 -70.9400 16.674 53 68 0.315

176 41.1912 -71.1248 41.1656 -71.1834 5.679 26 -120 0.218

191 41.1490 -71.1133 40.0055 -71.3208 128.070 53 -172 2.416

192 41.1466 -71.1228 41.1466 -71.1228 0.000 32 NA 0.000

193 41.1912 -71.1248 41.2499 -71.1463 6.758 339 -15 0.020

203 41.0800 -71.0500 40.0350 -70.5533 123.326 28 160 4.404

235 41.1300 -70.9200 41.1316 -70.9258 0.520 11 -70 0.047

247 41.1690 -71.0260 41.0690 -71.0248 11.096 14 179 0.793

257 41.1300 -70.9200 40.0200 -70.3700 131.653 369 159 0.357

250 41.1600 -70.9800 40.0327 -70.9971 125.074 96 -179 1.303

253 41.1300 -70.9200 41.1300 -70.9400 1.679 45 -90 0.037

282 41.1300 -70.9200 41.0900 -71.0080 8.622 6 -121 1.437

286 41.1200 -70.9550 41.1200 -70.9550 0.000 6 NA 0.000

293 41.1600 -70.9800 41.2517 -71.8733 75.610 339 -82 0.223

297 41.1200 -70.9550 41.1200 -70.9550 0.000 6 NA 0.000

298 41.1200 -70.9550 41.1200 -70.9550 0.000 6 NA 0.000

1 41.1017 -71.1674 41.0850 -71.1419 2.839 59 131 0.048
48

203 40.0350 -70.5533 40.0000 -71.0002 38.344 119 -96 0.322

250 40.0327 -70.9971 39.9861 -70.9481 6.652 118 141 0.056

Appendix 5. Description and disposition of the database

These digital files are provided on the accompanying CDROM.

Folder or filename Description of contents

SideScan Side-scan sonar images of each sampling 

site

GoPro Still photographs from GoPro camera 

mounted on the grab sampler

Lobster_Survey_Grain_Size.xls Sediment grain size composition of each 

grab sample

temps2014.txt, temps2015.txt Tidbit bottom temperature data

SNECVTS_database_2014.accdb Access database of 2014 lobster and 

bycatch data

SNECVTS_database_2015.accdb Access database of 2015 lobster and 

bycatch data

LobsterTag&RecaptureData_SNECVTS2015.xlsx Data from 2015 pilot tagging study

Report_Figures Digital files for each figure in the report
The Department of the Interior Mission

As the Nation's principal conservation agency, the Department of the Interior

has responsibility for most of our nationally owned public lands and natural 

resources. This includes fostering sound use of our land and water resources; 

protecting our fish, wildlife, and biological diversity; preserving the 

environmental and cultural values of our national parks and historical places;

and providing for the enjoyment of life through outdoor recreation. The 

Department assesses our energy and mineral resources and works to ensure that

their development is in the best interests of all our people by encouraging

stewardship and citizen participation in their care. The Department also has a 

major responsibility for American Indian reservation communities and for

people who live in island territories under US administration.

The Bureau of Ocean Energy Management

As a bureau of the Department of the Interior, the Bureau of Ocean Energy 

(BOEM) primary responsibilities are to manage the mineral resources located 

on the Nation's Outer Continental Shelf (OCS) in an environmentally sound and 

safe manner.