NOAA Grant Number: NA14NMF4540071

Grantee: Maine Department of Marine Resources (ME DMR)

Project Title: An Assessment of Sea Scallop Distribution and Abundance in Federal and Adjacent State Waters of the Gulf of Maine

Project Code: 14-SCA-11

Amount of Grant: 53,192 lbs. of scallops for 2014 ($558,515) and 35,461 lbs. of scallops for 2015 ($372,344)

Start Date: 03/01/2014

Period Covered by Report: 03/01/2014 - 06/30/2018

Executive Summary

The sea scallop fishery in the Northern Gulf of Maine (NGOM) occurs in federal waters and is managed by the New England Fishery Management Council (NEFMC). The fishery is managed by total allowable catch (TAC) independently of the rest of the EEZ sea scallop stock. A cooperative survey was carried out by the Maine Department of Marine Resources (DMR) and the University of Maine (UMaine) in May-June 2016. Survey results indicate that the biomass (by meat weight) of NGOM sea scallops targeted by the fishery (102+ mm or 4+ in. shell height (SH)) was approximately 728 MT in 2016. Landings from the NGOM were significantly higher in 2016 than any previous year and were largely from southern Jeffreys Ledge and northern Stellwagen Bank.

Maine state waters were surveyed in 2015-16. A strong year-class observed in Cobscook Bay in 2015 recruited to the fishery in 2016. Other rotational areas surveyed with notable densities of harvestable scallops were Machias Bay, Gouldsboro Bay/Dyers Bay and West Vinalhaven (2015) and Cutler coast, Chandler Bay and Lower Blue Hill Bay (2016).

Purpose

The major objective of the project was to develop a survey program to assess scallop distribution and abundance in federal waters of the NGOM Scallop Management Area (as defined in Amendment 11 to the Atlantic Sea Scallop Fishery Management Plan) and to estimate a biologically sustainable TAC for the stock. A dredge-based survey of the scallop resource in federal NGOM waters was conducted by DMR in collaboration with the commercial fishing industry and UMaine in May-June 2016 to provide information upon which management actions such as a TAC could be based. The scope of work of this project was extended into dredge- based surveys of state NGOM waters along eastern Maine and in Cobscook Bay during 2015-16.

An areal rotation scallop management plan was implemented by DMR within state waters prior to the 2012-13 season. This plan is in effect for 10 years (until 2020-21) in management zone 2

1 which covers the eastern Maine coast between W. Quoddy Head and Penobscot Bay. Management zone 2 is divided into multiple sections so that in any given season roughly one- third of the coast is open to fishing while the other two-thirds is closed to fishing to allow rebuilding.

The purpose of the state waters survey is to characterize and monitor the sea scallop resource and to compare results to previous years’ surveys in light of regulatory and environmental changes. It is necessary to monitor changes in abundance and stock size from year to year to evaluate effects of the fishery, document recruitment events and determine what is available for harvest. The survey provides information needed to evaluate management strategies such as harvest limits and rotational closures. The survey provides information on geographic distribution, relative abundance, population size structure, meat yield and occurrence of seed and sublegal scallops as well as estimates of harvestable biomass.

Approach

A.) Northern Gulf of Maine (federal waters) survey

Vessel and gear

F/V Clean Sweep, a 45 ft. side-rigged scallop vessel based in Bucks Harbor, ME, served as the platform for the entire survey. The 2016 NGOM survey occurred between 3 May and 24 June from the ports of Gloucester (MA) and Portland, Stonington, Southwest Harbor and Bucks Harbor (ME).

The survey gear was a 7 ft. wide New Bedford-style chain sweep dredge with 2 inch rings, 1¾ inch head bale, 3½ inch twine top and 10 inch pressure plate and equipped with rock chains (Fig. 1). The dredge was not lined. The dredge frame and clubstick were fabricated by Blue Fleet Welding (New Bedford, MA) and the ring bag was constructed by Pacheco Gear (E. Freetown, MA). Final assembly of the dredge and installation of the twine top was by Capt. Wally Gray (Stonington, ME) in 2015.

The survey dredge was of a configuration largely consistent with that used in 2002-08 inshore Gulf of Maine surveys (Kelly 2009; Schick and Feindel 2005), with the exception of a slightly larger pressure plate for towing in deeper water and smaller rings to allow better retention of small scallops. The gear was of a size which would allow it to be used in both nearshore and offshore parts of the Gulf of Maine, would facilitate sufficient bottom coverage and allow it to be transported over ground to various sampling locations throughout the region.

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Figure 1. View of survey dredge constructed in 2009.

Survey design

The NGOM management area is bounded by Cape Ann, Massachusetts in the west and the Canadian border in the east. Prior to 2009 when the first DMR/UMaine survey was conducted, the NGOM had limited fishery dependent and no recent fishery-independent data available to help design the survey. Scallops are not found uniformly throughout this region so sampling efforts were focused on a subset of areas in the NGOM.

In order to effectively allocate 2016 survey effort to areas with high scallop biomass, the southern three survey areas (Ipswich Bay, Jeffreys Ledge and northern Stellwagen Bank; the areas of highest fishing activity within the NGOM) were subdivided into high, medium and low density sub-strata. The delineation of these substrata was informed by fishermen’s input, VTR and VMS data, as well as survey data from 2009 and 2012. Tows were allocated among these sub-strata according to the Neyman allocation which ensures that sampling effort is allocated to areas of high variance to increase precision of abundance indices and refine the resulting biomass estimates:

WhSh nh  n H WhSh h1

3 where n is the total number of sampling stations for the survey area, H is the total number of strata, Wh is the proportion of stratum h area over the survey area, and Sh is the estimated standard deviation of historical data in stratum h.

Dredge tow stations were selected from a grid overlying each stratum. The dimensions of each grid unit were 1 km2. Target tow duration was 5 minutes (approximately 540 m) although fixed gear (lobster traps, gillnets) in some locations forced shorter tows. There were 238 stations completed within the seven (7) NGOM survey areas identified (Fig. 2).

Figure 2. The NGOM and the seven (7) strata selected for the survey: Area 1 (MSI = Machias Seal Island), Area 2 (MDI = Mount Desert Island), Area 3 (PB = Platts Bank), Area 4 (FL = Fippennies Ledge), Area 5 (IB = Ipswich Bay), Area 6 (SJL = southern Jeffreys Ledge) and Area 7 (NSB = northern Stellwagen Bank).

Initial tow allocations were based on the area delineation used in the 2009 and 2012 surveys however it became apparent from harvester reports that if we used these allocations the high density tows near Jeffreys Ledge would be missing scallop biomass. Strata were adjusted to incorporate a separate area for southern Jeffreys.

In order to effectively allocate survey effort to areas with high scallop biomass, the southern three survey areas (Ipswich Bay, Jeffreys Ledge and northern Stellwagen Bank; the areas of highest fishing activity within the NGOM) were subdivided into high, medium and low density sub-strata. The delineation of these substrata was informed by fishermen’s input, VTR and VMS data, as well as previous survey data from 2009 and 2012. Tows were allocated among these sub- strata according to the Neyman allocation which ensured that sampling effort was allocated to areas of high variance to increase precision of abundance indices and refine the resulting biomass estimates:

4 WhSh nh  n H WhSh h1 where n is the total number of sampling stations for the survey area, H is the total number of strata, Wh is the proportion of stratum h area over the survey area, and Sh is the estimated standard deviation of historical data in stratum h.

Sampling procedure

Stations to be sampled were plotted using Capn Voyager™ navigational software. A Garmin™ Map 76 GPS unit with Garmin™ GA 29 GPS antenna interfaced with a laptop computer displaying station location was used to position the vessel on station. Location and time were recorded at three points (dredge in, tow start and haulback) for each tow. A Juniper Allegro™ ruggedized handheld computer was also interfaced with a GPS unit to record time/date/location information.

A ruggedized handheld computer with an RS232 serial port input for digital calipers was used to facilitate rapid entry of shell measurements and other information while sampling. Data entry screens for the sampling programs and survey were configured using Data Plus Professional™ software, which aided in standardizing data entry, providing error checks and minimizing subsequent data auditing and keying (Schick and Feindel 2005).

The following sampling protocol was employed for each tow:

1.) Station information (location, time, depth) was entered from the wheelhouse.

2.) Bottom type was recorded as combinations of mud, sand, rock, and gravel based on sounder information and dredge contents. For example “Sg” designated a primarily sand substratum with some gravel (after Kelley et. al. 1998).

3.) Once the drag was emptied, a digital picture of the haul was taken.

4.) Scallops, sea cucumbers (Cucumaria frondosa) and ocean quahogs (Arctica islandica) were culled from the drag contents for subsequent measurement. Catches of the latter species were quantified because of their importance in other drag fisheries. While the survey gear is not suitable for formally sampling ocean quahogs their presence in the catch does suggest the existence of a bed below the sediment.

5.) Bycatch was enumerated using a 0-5 qualitative abundance scale corresponding to “absent”, “present”, “rare”, “common”, “abundant”, and “very abundant”.

6.) Total number of scallops was recorded. The total weight and volume of the scallop, sea cucumber, and ocean quahog catch was recorded.

5 7.) The shell height (SH; distance from the umbo to the outer edge, perpendicular to the hinge line) of individual scallops was measured. All scallops from catches of 100 animals or less were measured for SH. If >100 scallops were present at least 100 were measured. Where n > 1,000 a subsample of 10% was measured.

8.) On selected tows (normally every third or fourth tow) a subsample of 24 scallops, chosen to represent the catch of scallops ≥ 3½ in. shell height, were measured (shell length, width and height) and shucked for meat weight determination. Meats were placed in a compartmentalized box in the order that the animals were measured and later individually weighed on shore (using an Ohaus Navigator™ balance interfaced with the ruggedized handheld computer) and matched to the corresponding shell measurements.

Data analysis

Using the swept area method total exploitable stock biomass/abundance was estimated for each survey area, accounting for the efficiency of the dredge and the approximate selectivity. For each survey area identified above, the overall average abundance of swept area was estimated as:

 H  X  Wh X h h1  where X h is the average abundance of swept area for stratum h, H is the total number of strata, and Wh is proportion of the area of stratum h with respect to the survey area.

Because of the patchy distribution of scallops in this region, typical distribution-based estimates of error are not necessarily appropriate. Thus, bootstrapping procedures were used to estimate confidence limits around the abundance estimates. Because meat size for a given shell height is known to vary regionally within the Gulf of Maine, shell height-meat weight relationships were modeled individually for each sampling area using a generalized linear mixed model (GLMM) with sampling station as a random effect and depth as an environmental covariate.

Approximately 22,000 scallops were caught and counted, 6,200 were measured for SH and an additional 1,040 were sampled for shell size-meat weight determination on the 2016 NGOM survey. The smallest individual sampled was 5.0 mm (0.20 in.) SH and the largest was 173.0 mm (6.8 in.) SH. The largest number of scallops in a single tow was 3,949 on northern Stellwagen Bank.

B.) State waters surveys

Vessels

The 2015-16 surveys were conducted aboard two commercial scallop vessels each deploying the standardized survey drag. Vessels were the 39 ft. F/V Kristin Lee from Eastport, ME (surveyed Cobscook Bay and St. Croix R. in 2015-16) and the 40 ft. F/V Miss Sarah from Bucks Harbor, ME.

6 The Mt. Desert Rock and Machias Seal Is. areas were surveyed in June 2016 during the federal waters survey. Cobscook Bay and the St. Croix River were surveyed in October 2015 and November 2016 and eastern Maine (management zone 2) was covered in May 2015 and April- May 2016. Eastern Maine rotational areas scheduled to be open in upcoming seasons were the focus of these surveys. In addition some priority areas of western Maine (management zone 1) were surveyed in spring 2015.

Detailed bottom type information was collected with an Olex™ multibeam sonar in the Gouldsboro Bay/Dyers Bay and Chandler Bay rotational areas. The Chandler Bay map was were used to refine survey strata in 2016. The Gouldsboro Bay/Dyers Bay map was used in 2018.

Survey design

Cobscook Bay has the most productive scallop fishery within Maine waters and is thus sampled with the most frequency and with the highest intensity of the state survey zones. A direct assessment of scallop abundance for this stratum is made by using a systematic sampling design (systematic random stratified sampling in 2016). The Cobscook Bay survey was expanded in 2016 based on DMR scallop harvester reports and data from previous surveys and creation of a density-based stratification scheme. This scheme was refined based on fishermen’s input.

Cobscook Bay tow locations were based on a 500 m grid overlaying each area and substratum. This grid accommodated an average tow length of approximately 300 m. Tow time was 2.5 minutes and stations were sampled by a straight line tow. Boat speed averaged 3.5-4 knots.

Eastern and western Maine surveys in 2015 were conducted using randomly-selected tows within known productive scallop grounds of each rotational area. This approach was modified in 2016 using both previous surveys and DMR harvester reports to create high and low density grids of scallop distribution from which tows were selected using systematic random stratified sampling.

Data analysis

Area swept per tow was determined from tow distance (tow start to haulback) and drag width (7 ft., or 2.1 m). Tow distance was determined using Capn Voyager™ software. The scallop catch for each tow was standardized to density (number of scallops per square meter). Total scallop catch was divided into the following size categories:

“seed”: < 2½ in. (<63.5 mm) SH

“sublegal”: 2½ in. to < 4 in. (63.5 – <101.6 mm) SH

“harvestable”: ≥ 4 in. (≥101.6 mm) SH

Estimates of total abundance for each of the three size classes were calculated using the classic Cochran (1977) approach. For each of the six survey substrata identified above, the overall average abundance by area swept was estimated as:

7  H  X  Wh X h h1

 where X h is the average abundance of swept area for substratum h, H is the total number of substrata, and Wh is proportion of the area of substratum h with respect to the survey area. The associated standard error can be calculated as

 H 2 1 fh 2 std error (X)  Wh Sh h1 nh

2 nh where Sh is the variance estimated for substratum h, fh  is the finite population correction Nh for substratum h, and nh and N are the number of stations sampled and the total number of stations available for sampling, respectively, in substratum h. The finite population correction factor was ignored since the proportion of area sampled was small compared to the total area of each substratum.

The shell height (distance from the umbo to the outer edge, perpendicular to the hinge line) of individual scallops was measured. Most often all scallops in the tow were measured although for larger (>100 scallops) catches at least 100 scallops or 10% of the total (whichever was greater) was measured. Subsamples of 24 meats from ≥ 3.5 in. scallops in selected tows were obtained to determine shell size vs. meat weight relationships. Detailed bycatch information was also taken. All scallops were returned to the sea live except for those collected for meat weight samples.

On the spring 2015 Maine state waters survey approximately 9,100 scallops were caught and counted, 6,200 were measured for SH and an additional 892 were sampled for shell size-meat weight determination. The smallest individual sampled was 6 mm (0.2 in.) SH and the largest was 164 mm (6.5 in.) SH. The largest number of scallops in a single tow was 349 in Muscle Ridge.

During the 2015 Cobscook Bay/St. Croix R. survey approximately 24,900 scallops were caught and counted, 9,000 were measured for SH and an additional 630 were sampled for shell size- meat weight determination. The smallest individual sampled was 15.1 mm (0.6 in.) SH and the largest was 144.7 mm (5.7 in.) SH. The largest number of scallops in a single tow was 766 in the Whiting Bay subarea.

Approximately 9,600 scallops were caught and counted during the spring 2016 Maine state waters survey, 6,100 were measured for SH and an additional 1,200 were sampled for shell size- meat weight determination. The smallest individual sampled was 9.0 mm (0.4 in.) SH and the largest was 166.9 mm (6.6 in.) SH. The largest number of scallops in a single tow was 298 in the Cutler area

8 On the 2016 Cobscook Bay/St. Croix R. survey approximately 32,700 scallops were caught and counted, 12,300 were measured for SH and an additional 1,000 were sampled for shell size-meat weight determination. The smallest individual sampled was 10.6 mm (0.4 in.) SH and the largest was 164.6 mm (6.5 in.) SH. The largest number of scallops in a single tow was 586 in the Johnson Bay subarea. . Findings

A.) Northern Gulf of Maine (federal waters) survey

Recently the most heavily fished area within the NGOM has been the southwestern part within survey areas Ipswich Bay (IB), Southern Jeffreys Ledge (SJ) and Northern Stellwagen Bank (NSB). During the 2016 survey, within the IB area, most scallops were found on the western side near the state waters boundary (Fig. 3). In the NSB area, the main scallop biomass was found towards the southeastern boundary, and in the SJ area, the main scallop biomass was found towards the southwestern boundary. IB, SJ, and NSB had, multimodal SH distributions in 2016 (Fig. 4). The growth of the cohort observed in 2012 was evident in all areas. The modal SH on IB, SJ, and NSB were ~ 110 mm, ~95 mm, and ~90 mm respectively.

The survey on Platts Bank found the highest biomass on the southwest portion (Fig. 5). The growth of the cohort first observed in 2012 was evident (Fig. 6); the modal SH grew from ~75 mm in 2012 to ~110 mm in 2016. In both years there was a small proportion of scallops that were between 125 and 150 mm.

The survey in Machias Seal Island encountered scallops spread fairly evenly relative to the patchiness observed in the southern areas (Fig. 5). The only persistent aggregation of scallops was near Machias Seal Island, within state waters. Two age classes of scallops were seen in this region and were between 75 and 110 mm and 130-150 mm respectively (Fig. 6).

The survey in MDI encountered almost no scallops in 2016 as in past surveys (Fig. 5). There were scallops to the south of this area near Mount Desert Rock in 2016, but this small region is within Maine state waters and not part of the NGOM.

The survey on Platts Bank found the highest biomass on the southwest portion (Fig. 5). The growth of the cohort first observed in 2012 was evident (Fig. 6); the modal SH grew from ~75 mm in 2012 to ~110 mm in 2016. In both years there was a small proportion of scallops that were between 125 and 150 mm.

9

0 1- 3031 - 100101- 20200 0+

Figure 3. 2016 ME DMR NGOM survey – Distribution of scallop abundance on Ipswich Bay (upper left), Jeffreys Ledge (middle) and Stellwagen Bank (lower right).

10

Figure 4. SH distribution (mm) for Ipswich Bay (top), Jeffreys Ledge (middle) and northern Stellwagen Bank (bottom) during 2012 (red) and 2016 (black).

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Figure 5. 2016 ME DMR NGOM survey – distribution of scallop abundance on Machias Seal Is. (top), Mt. Desert Island (middle) and Platts Bank (bottom).

12

Figure 6. SH distribution (mm) for Machias Seal Is. (top), Mt. Desert Island (middle) and Platts Bank (bottom) during 2012 (red) and 2016 (black).

The relationship between shell height and meat weight varied by area, as in past surveys (Fig. 7). The best condition meats were in NSB and SJ, while the meats in MSI were clearly smaller for their size. Few samples of larger scallops were taken on PB, but those greater than 100 mm were of similarly poor condition to the scallops sampled in MSI.

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Figure 7. Relationship between shell height (mm) and meat weight (g) in 2016 for the survey areas.

The highest scallop biomass from this survey was observed on Stellwagen Bank (Fig. 8). Total biomass in the NGOM, assuming a dredge efficiency of 0.4 and selecting a conservative value (q 0.10 on the bootstrapped distribution) was estimated at ~1.75 million lbs. (795 MT) (Table 1). Using an exploitation rate of 0.2 the removable biomass was calculated to be ~0.4 million lbs. (159 MT). This information was used to inform a TAC for the NGOM for the 2017 season.

Table 1 - Biomass estimates from 2016 NGOM survey (F=0.2, Dredge Efficiency=0.4).

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Figure 8. 2016 ME DMR NGOM survey - estimates of harvestable biomass from each survey area.

A.) state waters surveys

Spring 2015

Thirty-four (34) stations were sampled in the Machias Bay rotational area in 2015 (Fig. 9). Four (4) tows contained no scallops. Seed density (0.004 per m2) (Figs. 10-11) was low and declined from 2013 (0.009 per m2).

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Figure 9. Density of scallops and size class composition by tow (Machias Bay), 2015 survey.

Figure 10 . Density of scallops and size class composition by tow and location (Machias Bay), 2015 survey.

16

Figure 11 . Scallop density by size (Machias Bay), 2015 survey.

There were 16 stations completed in 2015 in the Western Bay rotational area (Fig. 12). Five (5) tows contained no scallops.

The predominant size group was harvestables which occurred at a higher density (0.039 per m²) than 2013 in the adjacent open portion of Stratum 3 (0.022 per m²) (Figs. 13-14). In 2011 the harvestable density in this area was 0.014 per m².

Sublegal density (0.032 per m2) however was less than in the adjacent area in 2013 (0.045 per m2) Seed density remained low (0.003 per m²) comparable to 2013 (0.005 per m²).

17

Figure 12. Density of scallops and size class composition by tow (Western Bay), 2015 survey.

Figure 13 . Density of scallops and size class composition by tow and location (Western Bay), 2015 survey.

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Figure 14 . Scallop density by size (Western Bay), 2015 survey.

Figure 15. Density of scallops and size class composition by tow (Gouldsboro Bay/Dyers Bay), 2015 survey.

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Figure 16. Density of scallops and size class composition by tow and location (Gouldsboro Bay/Dyers Bay), 2015 survey.

Figure 17 . Scallop density by size (Gouldsboro Bay/Dyers Bay), 2015 survey.

20

Figure 18. Density of scallops and size class composition by tow (Blue Hill/Union R.), 2015 survey.

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Figure 19. Density of scallops and size class composition by tow and location (Blue Hill/Union R.), 2015 survey.

Figure 20. Scallop density by size (Blue Hill/Union R.), 2015 survey.

22

Figure 21. Density of scallops and size class composition by tow (Jericho Bay), 2015 survey.

Figure 22 . Density of scallops and size class composition by tow and location (Jericho Bay), 2015 survey.

23

Figure 23. Scallop density by size (Jericho Bay), 2015 survey.

Figure 24. Density of scallops and size class composition by tow (Eggemoggin/Southeast Harbor), 2015 survey.

24

Figure 25. Density of scallops and size class composition by tow and location (Eggemoggin/Southeast Harbor), 2015 survey.

Figure 26. Scallop density by size (Eggemoggin/SE Harbor), 2015 survey.

25

Figure 27. Density of scallops and size class composition by tow (W. Vinalhaven), 2015 survey.

Figure 28. Density of scallops and size class composition by tow and location (W. Vinalhaven), 2015 survey.

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Figure 29. Scallop density by size (W. Vinalhaven), 2015 survey.

Figure 30. Density of scallops and size class composition by tow (Matinicus), 2015 survey.

27

Figure 31. Density of scallops and size class composition by tow and location (Matinicus), 2015 survey.

Figure 32 . Scallop density by size (Matinicus), 2015 survey.

28

Figure 33 . Density of scallops and size class composition by tow (Muscle Ridge), 2015 survey.

Figure 34 . Density of scallops and size class composition by tow and location (Muscle Ridge), 2015 survey.

29

Figure 35 . Scallop size frequency (Muscle Ridge), 2015 survey.

Figure 36. Density of scallops and size class composition by tow (Muscongus Bay), 2015 survey.

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Figure 37. Density of scallops and size class composition by tow and location (Muscongus Bay), 2015 survey.

Figure 38. Scallop size frequency (Muscongus Bay), 2015 survey.

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Figure 39. Density of scallops and size class composition by tow (Damariscotta/Sheepscot), 2015.

Figure 40. Density of scallops and size class composition by tow and location (Damariscotta R.), 2015 survey.

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Figure 41. Density of scallops and size class composition by tow and location (Sheepscot R.), 2015 survey.

Figure 42. Scallop size frequency (Damariscotta/Sheepscot), 2015 survey.

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Figure 43. Density of scallops and size class composition by tow (Casco Bay), 2015.

Figure 44. Density of scallops and size class composition by tow and location (eastern Casco Bay), 2015 survey.

34

Figure 45. Density of scallops and size class composition by tow and location (western Casco Bay), 2015 survey.

Figure 46. Scallop size frequency (Casco Bay), 2015 survey.

35 Fall 2015

Figure 47. Scallop size frequency (Cobscook Bay), 2015 survey. Scallops were mostly sublegal; predominantly 3.4-3.9 inch shell height. 29% of scallops were 4.0-4.7 inch shell height.

36 Cobscook Bay (Stratum 1) scallop size frequency (n = 6,675) (excluding Whiting/Dennys Bay) 2014 79 stations 0.16

0.14 ----> harvestable 0.12

0.1

0.08 Frequency 0.06

0.04

0.02

0 15 25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 Shell height (mm)

Figure 48. Scallop size frequency (Cobscook Bay), 2014 vs. 2015 survey.

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Figure 49. Scallop meat weight and count per lb. at 4.0, 4.5 and 5.0 inch shell height, Cobscook Bay, as reported in ME DMR surveys.

Figure 50. Cobscook Bay estimated harvestable (>4 in. SH) scallop biomass (meat weight), 2003-15. The 2015 estimate of 346 thsd. lbs. was the 4th highest of the time series but a significant decline from 2014.

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Figure 51. Whiting Bay/Dennys Bay estimated harvestable (>4 in. SH) scallop biomass (meat weight), 2003- 15. The 2015 estimate was 30.3 thsd. lbs. which was a 26% decrease from 2014 and the third consecutive year of decline.

Spring 2016

Figure 52. Density of scallops and size class composition by tow and location (Cutler coast), 2016 survey.

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Figure 53 . Scallop density by size (Cutler coast), spring 2016 (top) and projected to December 2016 (bottom).

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Figure 54. Density of scallops and size class composition by tow and location (Chandler Bay), 2016 survey.

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Figure 55. Scallop density by size (Chandler Bay), spring 2016 (top) and projected to December 2016 (bottom).

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Figure 56. Density of scallops and size class composition by tow and location (Pigeon Hill/Narraguagus), 2016 survey.

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Figure 57. Scallop density by size (Pigeon Hill/Narraguagus), spring 2016 (top) and projected to December 2016 (bottom).

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Figure 58. Density of scallops and size class composition by tow and location (Mt. Desert/Cranberry Is.), 2016 survey.

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Figure 59. Scallop density by size (Mt. Desert/Cranberry Is.), spring 2016 (top) and projected to December 2016 (bottom).

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Figure 60. Density of scallops and size class composition by tow and location (Lower Blue Hill Bay), 2016 survey.

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Figure 61. Scallop density by size (Lower Blue Hill Bay), spring 2016 (top) and projected to December 2016 (bottom).

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Figure 62. Density of scallops and size class composition by tow and location (Isle au Haut), 2016 survey.

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Figure 63. Scallop density by size (Isle au Haut), spring 2016 and projected to December 2016.

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Figure 64. Density of scallops and size class composition by tow and location (North Haven), 2016 survey.

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Figure 65. Scallop density by size (North Haven), spring 2016 (top) and projected (bottom) to December 2016.

52 Fall 2016

Figure 66. Density of scallops and size class composition by tow and location (Cobscook Bay), 2016 survey.

Figure 67. Scallop density by size (Cobscook Bay), comparison between same stations, 2015 and 2016.

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Figure 68. Scallop density by size (Cobscook Bay), all survey stations, 2015 and 2016.

Figure 69. Scallop density by size (Cobscook Bay), comparison between same stations, 2014-2016.

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Figure 70. Cobscook Bay scallop harvestable (>4 in.) biomass density by subarea, fall 2016.

Figure 71. Scallop density by size (Whiting Bay), all survey stations, 2015 and 2016.

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Figure 72. Fine-scale bottom features of Gouldsboro Bay and Dyers Bay produced by DMR scallop survey mapping project using Olex™ system. (Gradation shows hardest bottom in red and softest bottom in green).

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Figure 73. Fine-scale bottom features of Chandler Bay produced by DMR scallop survey mapping project using Olex™ system. (Gradation shows hardest bottom in red and softest bottom in green).

Conclusions

Northern Gulf of Maine (federal waters)

A significant increase in NGOM harvestable scallop biomass was observed on the 2016 survey. Fishing year 2016 marked a high point in landings (over 381,000 lbs.) since the NGOM was established in 2008 (NEFSC 2018). Limited access (LA) vessels fishing under days-at-sea (DAS) management in the NGOM harvested roughly 293,000 lbs. while approximately 89,000 lbs. were landed by limited access general category (LAGC) IFQ and LAGC NGOM vessels. LA vessels had not previously been fishing in the NGOM. Biological advice and management of the area are complicated by having separate constraints on harvesting by LA and LAGC vessels.

57

State waters

The spring 2015 survey indicated strong recruitment in the Machias Bay area with a significant density of sublegal scallops expected to reach legal size by the 2015-16 season. Gouldsboro Bay/Dyers Bay also appeared productive with predominantly sublegal and harvestable scallops present. Eggemoggin Reach/Southeast Harbor had a small abundance of harvestable scallops present. West Vinalhaven had the highest density in the time series for this area and was comprised mostly of harvestable scallops in the larger size range. Matinicus was mostly low but some recruitment was seen. Poor abundance was observed in Western Bay, Blue Hill/Union River and Jericho Bay.

For western areas Muscle Ridge had multiple size groups present including harvestable. Casco Bay also had a wide range of scallop sizes present including harvestable mostly in western Casco Bay. Damariscotta River was patchy with some scallops present in the upper portion of the river. The Sheepscot River was mostly poor with some recruitment observed in the Little Sheepscot area. Muscongus Bay was poor.

In fall 2015 Cobscook Bay had mostly sublegal scallops in the 3.4-3.9 in. SH range. There was a reasonable density of legal scallops but estimated harvestable biomass declined significantly from 2014. Whiting Bay/Dennys Bay harvestable biomass declined 26% from 2014.

The spring 2016 survey indicated significant abundance of scallops in the Cutler coast area, including a high proportion of sublegals which were expected to reach harvestable size in 2016- 17. Scallops were distributed throughout the area including deeper water locations. Chandler Bay had several locations with a high proportion of harvestable scallops. Pigeon Hill/Narraguagus Bay contained higher numbers of scallops, mostly harvestable, than previous surveys. Lower Blue Hill Bay contained a significant abundance of harvestable scallops with a high proportion >120 mm SH. North Haven had a few small patches of scallops of multiple sizes. Very low numbers of scallops were observed in the Mt. Desert/Cranberry Is. and Isle au Haut Bay areas.

In fall 2016 Cobscook Bay had a higher proportion of harvestable scallops than 2015, probably a result of the large group of 2015 sublegals that grew into legal size range. Highest harvestable biomass density was in the Johnson Bay subarea. Whiting Bay/Dennys Bay also had a higher proportion of legals than 2015.

Evaluation

The primary objective of the project, to continue development of a survey program to assess scallop distribution and abundance in federal NGOM waters and to estimate a biologically sustainable total allowable catch (TAC) for the stock, was accomplished. The 2016 NGOM survey built upon the foundation for long term monitoring established in 2009.

The project was also successful in continuing DMR’s efforts to monitor and assess the state waters portion of the NGOM resource in 2015-16. This information will be important in

58 monitoring the status of the nearshore resource and evaluating effects of such measures as rotational management and trigger mechanisms to enact in-season closures.

Dissemination of project results

Results of this project were presented at the following venues:

Invertebrate Subcommittee (Sea Scallop Assessment), Northeast Fisheries Science Center, Woods Hole, MA, February 2018 (results of NGOM federal waters survey)

New England Fishery Management Council Scallop Plan Development Team, various meetings, 2016-17 (results of federal waters survey and development of TAC options for NGOM)

Maine DMR Scallop Advisory Council, 2016

Maine Fishermen’s Forum, 2017

Results were also presented in the following document:

Northeast Fisheries Science Center (NEFSC). 2018. 65th Northeast Regional Stock Assessment Workshop (65th SAW) Assessment Report.

Expenditures

The RSA TAC allocation to the project was 53,192 lbs. of scallops for 2014 ($558,515) and 35,461 lbs. of scallops for 2015 ($372,344). The amount expected for research from this allocation was $372,344 based on the proposed budget (Table 2).

Major expenditure categories during 2015-16 were 1.) vessel services (NGOM federal waters survey and 2015-16 state waters surveys), 2.) support for a University of Maine graduate student, 3.) construction of two (2) new survey dredges and replacement of ring bags on two (2) other dredges, 4.) personal services for a DMR Specialist II and a contracted field assistant, 4.) travel by survey personnel, and 6.) field gear and supplies including dredge sensors.

All project funds were expended to complete the project (Table 3).

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Serchuk, F., and S. Wigley. 1984. Results of the 1984 USA sea scallop research vessel survey: status of sea scallop resources in the Georges Bank, Mid-Atlantic and Gulf of Maine regions and abundance and distribution of Iceland scallops off the southeastern coast of Cape Cod. U.S. Natl. Mar. Fish. Serv. Northeast Fish. Cent. Woods Hole Lab. Ref. Doc. 83-84. 74 p.

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Spencer, F. 1974. Final report: offshore scallop survey - Cape Ann, Massachusetts to Maine- Canadian border. Maine Department of Marine Resources. 16p.

Truesdell, S.B., K.H. Kelly, C.E. O’Keefe and Y. Chen. 2010. An assessment of the sea scallop resource in the Northern Gulf of Maine management area. Report to the 50th Stock Assessment Working Group, NMFS/NEFSC, Woods Hole, MA, 26 p.

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