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. 2 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 h1 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 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.