David B. Rudders

Sally Roman

Jeanna Hudson

Virginia Institute of Marine Science

Sea Scallop Plan Development Team

Falmouth, MA

August 25-26, 2015

Preliminary – PDT use only.

2015 VIMS-Industry Cooperative Surveys The 2015 Campaign – Mid-Atlantic Bight

2015 VIMS-Industry Cooperative Surveys Primary Project Objectives

• Assess the abundance and

distribution of scallops in the Mid-

Atlantic Bight. • Mid-Atlantic Bight (Block Island to

VA/NC)

– 2015 SAMS Area

– 2015 SAMS Extended Area

• Estimate exploitable biomass.

• Biomass of scallops available for

capture with 4 inch ring commercial

dredge.

• Calibrate a number of similarly

classed vessels.

• Horsepower, LOA, berths

2015 VIMS-Industry Cooperative Surveys Secondary Project Objectives

• Gear performance

• Estimate size selectivity and relative

performance of 4.0 ring turtle CFTDD.

• Scallop Biology & Product Quality

• Spatially and temporally explicit shell

height:meat weight relationships.

• Assess metrics associated with product

quality.

• Examine the incidence and pathology of

the shell disease observed in the MAB.

• Investigate newly observed parasite in

scallop meats

• Finfish Bycatch

• By utilizing a commercial dredge we can

get a snapshot of finfish bycatch rates

and species assemblages in the

surveyed areas.

• Additional Sample Requests

• Whelks, scallop shell and starfish

2015 VIMS-Industry Cooperative Surveys What’ s new

• Sampling design – Stratified random design

– NMFS shellfish strata plus

– Allocation

– Area, prior year catch

data (biomass, number)

• Vessels • 2 of 3 vessels were new to the survey

• Carolina Capes II (new), K.A.T.E. II

(new), Celtic (veteran).

• Data acquisition system • Electronic boards (1mm res.)

• Custom front end to Access DB

• Integrated with Marel scale

• Personnel • Sally Roman as lead

• All other protocols remained the

same (see scallop survey peer

review materials for details)

2015 VIMS-Industry Cooperative Surveys Analytical Framework

j

j

j

SubAreaEfficiency

erTowAreaSweptp

eaTowinSubarCatchWtper

ssTotalBioma

• Area swept per tow • Navigational info

• Tilt sensor

• Catch weight per tow (stratified means

and variances) • Length frequencies

• Length-weight relationship (for this analysis regional

SARC 59).

• Selectivity (Yochum and DuPaul, 2008)

• Efficiency (constant)

• Values from SARC 2014 – 65%Commercial Dredge

– 40% NMFS Survey Dredge

• Sub-Area (constant) • Dependant upon the spatial extent of the survey

domain

• 2015 NMFS SAMS

• 2015 SAMS VIMS extended

2015 VIMS-Industry Cooperative Surveys SAMS Region/Zone

• The projection model

(SAMS) examines the

resource on a variety of

spatial scales. • region, zone

• The VIMS survey

included some areas

outside of the NMFS area

specification.

• Biomass estimates will

be presented in the

context of the NMFS

specification as well as

the VIMS expanded area

2015 VIMS-Industry Cooperative Surveys SH:MW Relationship

~5000 SH:MW samples were taken from all stations that had scallops. (~10-15/station). Sampling extended for nematode

surveillance.

The objective is to construct a model

to predict meat weight based on a suite of potential covariates (i.e. shell height, depth, SAMS area, sex, disease…).

Average depth was calculated for each tow from tilt sensor

A GLMM was used to fit model (Gamma distribution, log link, random effect at the station level) with SAS PROC GLIMMIX.

2014 VIMS-Industry Cooperative Surveys SH:MW Results

•MAB SAMS Areas

•Significantly different relationships between areas.

•Likely a function of average depths for each of subarea, as well as the temporal spread of the

sampling

Meat weight anomalies (MAB)

SARC 59

2015 VIMS-Industry Cooperative Surveys SH:MW Results – Comparisons with SARC59

•These results highlight the spatial and temporal variability in the SH:MW relationship.

•Overall, the SARC 59 estimates for the MAB are in agreement with the observed SHMW

from the VIMS 2015 survey.

•Biomass of an area is a dynamic process that has significant spatial and temporal

components that warrant consideration in the specification process.

SAMS Region Avg_Depth VIMS Est. @120mm SARC Est. @120mm % Difference

DMV 64.37 29.60 31.50 -6.42

ET 56.20 31.77 29.66 6.65

HC 59.64 32.53 31.75 2.40

HCnr 51.97 31.15 33.40 -7.22

HCsr 54.85 30.47 32.75 -7.47

LI 53.16 31.44 33.46 -6.41

VA 62.58 23.13 29.67 -28.28

2015 VIMS-Industry Cooperative Surveys Length Frequency- SAMS Region

2015 VIMS-Industry Cooperative Surveys Length Frequency- SAMS Zone

2015 VIMS-Industry Cooperative Surveys Scallop Distribution-MAB

2015 VIMS-Industry Cooperative Surveys Total Biomass

SAMS Region Total Biomass (mt) SE Biomass_est Density (scal/m^2) Avg MW (g) Total #

DMV 8,719 1,090.47 0.335 10.86 959,100,951

DMV expanded 11,458 2,174.98 0.282 9.68 1,393,034,040

ET 29,997 3,337.15 1.196 6.91 5,825,998,460

ET expanded 30,079 3,399.06 1.156 6.89 5,823,702,868

HC 20,136 2,682.61 0.533 5.79 4,441,144,376

HCnr 12,364 2,051.37 0.244 8.11 1,397,823,435

HCsr 4,239 648.62 0.154 9.84 512,547,623

LI 9,733 1,381.97 0.106 10.56 937,812,376

Virginia 150 30.65 0.051 2.96 70,221,890

SAMS Zone Total Biomass (mt) SE Biomass_est Density (scal/m^2) Avg MW (g) Total #

DMV 8,719 1,090.47 0.335 10.86 959,100,951

DMV expanded 11,458 2,174.98 0.282 9.68 1,393,034,040

ET_NW 11,098 1,671.91 1.291 6.67 2,315,480,122

ET_NM expanded 11,134 1,709.30 1.271 6.67 2,384,306,693

ET_SE 18,495 1,990.40 1.168 7.08 2,745,262,745

ET_SE expanded 18,664 2,143.45 1.114 7.06 3,021,373,345

ETin 106 28.02 0.006 32.17 4,258,608

HCS 17,257 1,824.00 0.808 5.65 3,513,328,962

HCSin 2,803 1,090.07 0.091 8.23 302,025,730

HCSoff 9 1.92 0.005 3.13 3,002,557

HCnr 16,848 2,394.67 0.244 8.11 1,397,823,435

HCsr 4,239 648.62 0.154 9.84 512,547,623

BI 1,074 189.85 0.091 15.85 69,354,272

LI 8,662 1,169.01 0.108 10.17 867,302,330

Virginia 150 30.65 0.051 2.96 70,221,890

2015 VIMS-Industry Cooperative Surveys Exploitable Biomass Survey

SAMS Region Exp Biomass (mt) SE Biomass_est Density (scal/m^2) Avg MW (g) Total #

DMV 4,450 627.87 0.073 25.28 208,622,805

DMV expanded 5,592 1,210.76 0.053 24.70 260,296,737

ET 13,733 2,256.15 0.156 24.31 759,660,613

ET expanded 13,683 2,292.93 0.150 24.30 757,402,996

HC 6,414 1,007.65 0.042 22.74 346,562,207

HCnr 2,946 246.71 0.022 21.99 126,730,833

HCsr 1,332 161.77 0.021 21.51 70,954,584

LI 3,737 431.34 0.017 25.27 146,285,240

Virginia 4 0.97 0.001 6.59 921,238

SAMS Zone Exp Biomass (mt) SE Biomass_est Density (scal/m^2) Avg MW (g) Total #

DMV 4,450 627.87 0.073 25.28 208,622,805

DMV expanded 5,592 1,210.76 0.053 24.70 260,296,737

ET_NW 3,984 1,088.19 0.150 24.51 269,304,104

ET_NM expanded 3,993 1,112.62 0.148 24.51 277,304,932

ET_SE 9,444 1,307.53 0.165 24.17 387,458,491

ET_SE expanded 9,451 1,403.68 0.157 24.16 424,464,792

ETin 92 27.24 0.004 45.06 2,654,279

HCS 5,311 745.51 0.061 22.44 265,824,728

HCSin 1,022 128.13 0.011 26.13 36,531,195

HCSoff 0 0.06 0.000 5.29 36,176

HCnr 4,014 288.00 0.022 21.99 126,730,833

HCsr 1,332 161.77 0.021 21.51 70,954,584

BI 572 89.13 0.028 27.29 21,302,876

LI 3,167 294.60 0.016 24.95 125,854,054

Virginia 4 0.97 0.001 6.59 921,238

2015 VIMS-Industry Cooperative Surveys Exploitable Biomass - Commercial

SAMS Region Exp Biomass (mt) SE Biomass_est Density (scal/m^2) Avg MW (g) Total #

DMV 5,595 983.69 0.0821 28.76 234,785,407

DMV expanded 6,295 1,557.29 0.0552 24.70 272,692,874

ET 22,053 5,978.06 0.2007 26.92 977,904,453

ET expanded 21,933 6,069.93 0.1935 26.92 974,825,012

HC 7,424 1,788.97 0.0398 28.00 332,112,170

HCnr 2,583 285.45 0.0137 33.14 78,779,879

HCsr 1,244 226.84 0.0150 29.30 49,768,056

LI 3,603 516.52 0.0116 34.71 102,380,450

Virginia 8 6.16 0.0002 19.92 301,580

SAMS Zone Exp Biomass (mt) SE Biomass_est Density (scal/m^2) Avg MW (g) Total #

DMV 5,595 983.69 0.0821 28.76 234,785,407

DMV expanded 6,295 1,557.29 0.0552 28.47 272,692,874

ET_NW 6,464 2,138.00 0.1547 27.29 277,607,146

ET_NM expanded 6,495 2,182.76 0.1524 27.29 285,929,612

ET_SE 14,824 3,866.60 0.2395 26.75 562,799,671

ET_SE expanded 14,816 4,150.81 0.2272 26.75 616,129,665

ETin 120 45.35 0.0058 37.34 4,194,187

HCS 6,096 1,319.00 0.0595 27.34 258,938,174

HCSin 1,265 190.45 0.0097 35.98 32,351,401

HCSoff 10 3.25 0.0008 20.32 502,870

HCnr 3,520 333.22 0.0137 33.14 78,779,879

HCsr 1,244 226.84 0.0150 29.30 49,768,056

BI 307 87.58 0.0122 34.69 9,308,653

LI 3,296 404.18 0.0116 34.71 93,123,966

Virginia 8 6.16 0.0002 19.92 301,580

2015 VIMS-Industry Cooperative Surveys Summary

• The good

• Biomass in the MAB closed areas appear to be strong

• Very high levels of recruitment (2 year old animals, 40-50

mm).

• Causes of concern

• Adult biomass in the MAB open areas was low and lack of

strong 3 year old animals to fill in for the 2016 FY

• Spatial co-occurrence of the highest areas of seed and

adult scallops (esp. in the ET_SE).

• Emergence of a nematode parasite observed in the scallop

meats.

Acknowledgements

• The owners, captains and crews;

• F/V Carolina Capes II

• F/V K.A.T.E II

• F/V Celtic

• Sarah Borsetti, Daniel Smith, Lee

Rollins, Crystal Vaughn, Nick

Cardoso

• Support from NMFS NEFSC: Dvora

Hart, Russ Brown, Vic Nordahl.

• Scientific staff that participated on

the cruises.

• Funding through Sea Scallop RSA

program.