NOAA Technical Memorandum NMFS-AFSC-227 Results of the 2010 Eastern and Northern Bering Sea Continental Shelf Bottom Trawl Survey of Groundfish and Invertebrate Fauna by R. R. Lauth U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service Alaska Fisheries Science Center August 2011 NOAA Technical Memorandum NMFS The National Marine Fisheries Service's Alaska Fisheries Science Center uses the NOAA Technical Memorandum series to issue informal scientific and technical publications when complete formal review and editorial processing are not appropriate or feasible. Documents within this series reflect sound professional work and may be referenced in the formal scientific and technical literature. The NMFS-AFSC Technical Memorandum series of the Alaska Fisheries Science Center continues the NMFS-F/NWC series established in 1970 by the Northwest Fisheries Center. The NMFS-NWFSC series is currently used by the Northwest Fisheries Science Center. This document should be cited as follows: Lauth, R. R. 2011. Results of the 2010 eastern and northern Bering Sea continental shelf bottom trawl survey of groundfish and invertebrate fauna. U.S. Dep. Commer., NOAA Tech. Memo. NMFS- AFSC-227, 256 p. Reference in this document to trade names does not imply endorsement by the National Marine Fisheries Service, NOAA. NOAA Technical Memorandum NMFS-AFSC-227 Results of the 2010 Eastern and Northern Bering Sea Continental Shelf Bottom Trawl Survey of Groundfish and Invertebrate Fauna by R. R. Lauth Alaska Fisheries Science Center 7600 Sand Point Way N.E. Seattle, WA 98115 www.afsc.noaa.gov U.S. DEPARTMENT OF COMMERCE Rebecca M. Blank, Acting Secretary National Oceanic and Atmospheric Administration Jane Lubchenco, Under Secretary and Administrator National Marine Fisheries Service Eric C. Schwaab, Assistant Administrator for Fisheries August 2011 This document is available to the public through: National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161 www.ntis.gov Abstract From June to August 2010, the National Marine Fisheries Service’s Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, conducted its 29th annual eastern Bering Sea (EBS) continental shelf bottom trawl survey of groundfish and invertebrate fauna. In addition, the 2010 survey coverage was expanded to include the northern Bering Sea (NBS). The expanded study area covered the entire Bering Sea continental shelf from 20 to 200 m bottom depth to the U. S.-Russian Convention Line between the Alaska Peninsula and the Bering Strait, including Norton Sound. Three stern trawlers, the 43.5-m FV Alaska Knight, the 40-m FV Aldebaran, and the 38-m FV Vesteraalen were chartered to sample this survey area. Demersal populations of fishes and invertebrates were sampled by trawling for 30 minutes at stations centered within a stratified systematic grid consisting of a total of 376 stations in the EBS and 145 stations in the NBS. At each station, species composition of the catch was determined, and length distributions and age structure samples were collected from ecologically and commercially important species. All survey stations were sampled successfully in the EBS, and all but three stations were sampled successfully in the NBS. For the fifth consecutive year, average surface (5.4°C) and bottom (1.4°C) water temperatures for the EBS shelf were well below the long-term means from 1982 to 2009 for the surface (6.6°C) and for the bottom (2.3°C). A total of 120 species of fishes representing 23 families and 74 genera, as well as 199 species of invertebrates representing 14 phyla, were identified in the catches from both the EBS and NBS. Fish taxa in the EBS accounted for 74% of the total CPUE compared with the NBS where fish taxa accounted for only 38% of the total CPUE. In the EBS, walleye pollock (Theragra chalcogramma), Pacific cod (Gadus macrocephalus), yellowfin sole (Limanda aspera), and rock sole (Lepidopsetta spp.) comprised iii 77% of the total fish biomass, and in the NBS, yellowfin sole and Alaska plaice (Pleuronectes quadrituberculatus) comprised 61% of the total fish biomass. The majority of invertebrate biomass in both the EBS (67%) and NBS (67%) consisted of echinoderms and crustaceans. Survey results presented herein include abundance estimates for fishes and invertebrates, geographic distributions and abundance-at-length of the more common fish species, and summary surface and bottom temperature data during the summer survey period. Appendices provide station data, summarized catch data by station, species listings, and detailed analyses of abundance and biological data of the sampled populations. iv Contents Introduction......................................................................................................................................1 History of Bering Sea Bottom Trawl Surveys.....................................................................5 Methods............................................................................................................................................6 Survey Area and Sampling Design......................................................................................6 Survey Vessels and Sampling Gear.....................................................................................7 EBS Sampling Logistics and Stratification Scheme..........................................................10 NBS Sampling Logistics and Stratification Scheme.........................................................12 Standard Sampling Procedures..........................................................................................12 Catch Data Analysis...........................................................................................................18 Additional Research Projects.............................................................................................19 Results and Discussion..................................................................................................................22 Ocean Conditions...............................................................................................................22 Species Composition..........................................................................................................23 Relative Abundance...........................................................................................................23 Biomass, Abundance, Distribution, CPUE, and Size Composition of Principal Species and Species Groups.........................................................................30 Summary of Results for Selected Major Eastern and Northern Bering Sea Fish Fauna..................................................................................................31 Walleye Pollock............................................................................................................31 Pacific Cod....................................................................................................................40 Yellowfin Sole..............................................................................................................40 Northern and Southern Rock Sole (grouped)................................................................41 Flathead Sole.................................................................................................................41 Bering Flounder............................................................................................................54 Alaska Plaice.................................................................................................................55 Greenland Turbot..........................................................................................................68 Arrowtooth Flounder....................................................................................................69 Kamchatka Flounder.....................................................................................................78 Pacific Halibut..............................................................................................................78 Biomass, Abundance, Distribution and CPUE of Other Fish Taxa...................................88 Spatial Distribution of Selected Invertebrates...................................................................88 Acknowledgments........................................................................................................................124 Citations.......................................................................................................................................125 v Appendices...................................................................................................................................133 Appendix A: Station and Catch Data...............................................................................135 Appendix B: Rank Order of Relative Abundance of Fish and Invertebrates..................183 Appendix C: List of Species Encountered.......................................................................207 Appendix D: Population Estimates by Sex and Size Groups..........................................225 vi Introduction From June to August 2010, the National Marine Fisheries Service (NMFS) Resource Assessment and Conservation Engineering (RACE) Division of the Alaska Fisheries Science Center (AFSC) conducted its 29th annual EBS (eastern Bering Sea) continental shelf bottom trawl (BT) survey of groundfish and invertebrate fauna. In addition, the 2010 survey coverage of the continental shelf was expanded to include the NBS (northern Bering Sea),which is bounded by the shelf break and the U.S.-Russian Convention Line in the west, the Bering Strait in the north, and Norton Sound in the east (Fig. 1). The 2010 EBS and NBS shelf surveys were conducted concurrently with the 2010 EBS upper continental slope BT survey (Hoff and Britt 2011) and together they represented the most comprehensive BT survey coverage of the Bering Sea (roughly 800,000 km2) since the U.S. government began scientific BT surveys in Alaska. Sampling on the NBS shelf was done in conjunction with the annual EBS shelf bottom trawl survey. The methodology for sampling both the EBS and NBS was exactly the same, but the main objective for sampling each area was different. The EBS shelf supports one of the most productive groundfish and crab fisheries in the world (Bakkala 1993) including commercially valuable species such as walleye pollock (Theragra chalcogramma), yellowfin sole (Limanda aspera), Pacific cod (Gadus macrocephalus), snow crab (Chionoecetes opilio), blue king crab (Paralithodes platypus), and red king crab (P. camtschaticus). Fishery-independent data from annual EBS bottom trawl surveys are vital to the management and conservation of commercial and non-target groundfish and crab species under the North Pacific Fishery Management Council (NPFMC) fisheries management plans. In contrast, the NBS has no large-scale commercial fisheries; however, climate change is a concern because of its potential to fundamentally alter the biological community thereby impacting fishes, crabs, marine mammals and the subsistence Bering SFtFr-1a8iFtF-01FF-02 EE-19EE-18 DD-20DD-19 EE-01EE-02 62°N Lin e CC-21CC-20CC-19DD-18DD-01DD-02DD-03 2 65550864°°°°NNNN 0 501NE0ao0srttheM-e3r2PnrL-U2R3M-3n2-- N3.1302O-B13 -SP1Q3LBM-R01--3.e33-S-1N313 O0-01e3P---r313-0Q3 M0iLr0R-n--S3N22-iR03-O993-n02Tg-0P29-33QL9u-Rg20M- -2-9S22N-Ss809-29 2-KOT82U9S--Ps8Q-22-02eL2i-MG-9728R-92H2S8--8Ne-22-7aa-2I2O27-6-TQ8JU2628-PKP--a7Q2P6-22Vn F--O2L8R227H-M26-G- 8-s22227672--- -S7N825722226IO7--Ts25O-6JC6h5222PU-46--KPN7256V22Q-F-Q2-LhO7W62-52R2Me--2G6-7Po2260252H--7N-S462-22O62I52e-2T-J-6-5U7l262O522-24-n-2K524220fP45-QP6N2V55F46-lLQ-OW-262-Rv2G--Mf22P42255X2H--56N-S-32224522-OIT2-e-2-5-4625J32-22U24-62K-42PE325342V-FP54-42--nWLR32-Q22-OG52M-2t3XG42-2PN-5HSH2-22i2--YF23TU2224O--54-IJJG5-I22-22-2543H2-2PI-2K2-3422222Q2o2V2E35224--WF22422LR32320---22G2M12-2-2G32S--2H2X2n4N113212F-Z-1-12-YH-32OI242I- 2022THZJ-2-UP213G2411---2-V2J222K2-2-E1Q2G42I2-2W1LR2F123-420G-1-23F2-M22S-13-22-XN22-1H20202YH2-2-Z210-022O-T0-230II-202GZ-HJ222UA-11P-3212--30V2K2E92A22--W0Q2F22-1R00-L-03-2G2X-12-1SM12-J-1-12220292-I93H-Z-9NG2-912Y12201OC2TZIHI-2-0A--9JF1HUD102-2P-1--1G-V2KAB29112E01Q-12-W99-2-1189F1-20-B29L9-2R-12X1GM811--90J2-1-1SN922112H-8-Y8I1-0-822B18Z1-12-9-1T8OC-2I0U11S29--8Z1J9P-00D91-KB-121V8---E01-1Q21t828-01-W-B.1901-L02FR81M-90 YX-G18-01-S-2LAN-112-0H--91-B12-T21-810a-01O9C-0UI0-108-P-0191J02DB0-w8V--K1--01921QW1E1B0--LF-28R91080r--1----MG0XS92102e-110NAH12801--T--29OB-n118-00U-CA-I000-981-P2-1JDc1V0AB-30-20K81-0-WE2-Q3-0eL1-B081-301FR-X-021M---8G0Y309S-110-2-0NH3-0-21T-B918-1O03001UC-8-IA--8-002031J-0VB0DA--2C0K31-004WQ3-EB02-R-0-14CLF10X-03---M1G--S0084-10-3-Y000HZ102N4T-8--1N-23B4008OAZU01-0I---0C023-40JB-A1V-0-00Du4200-K3WC-B4--05ER01L2030-X-T-FCn045-0-M-21-0ISG00-0-Y05-N4-0Zs010-H5-i02-34-UA20B0OvZ-30501.0I-C34-AB-2--05-JV400a00DK0C-W5-B-3-065EL2004--0Ck-X60F0--2M5-0300G065Y---N2Z 0H00-536B--A0Z-62300-0I-C5B-A0-D306J500CK6-B7---06300EL0C--F70M3G06-7-Y--00N6Z300H---67BA00Z073-I-C07-6-AB4-0J0060DC-7-K-B8E07040L-C--80-M4F7-000G08-Z-N74-08H07A-0Z4-80B-I07-AC-0J807D0BCK8---500E80--LC-005FM980--G-0590-80-0H9-8A0509BI-8A-90JD0BC-9-K0E9-0-LC1-0F69-0-0G16--0901HA0-9601AIB--J101C-B-00E10KC-7F-00-1G-17-011-0HA711BAI-1-1JCB1-1-0EK1C1-80F-1-G-1810-H211-812B-I1-2JCB12-12K-C0F2--9G10-H1A29-31B-AI-1C31BJ-31C-3-101F-K310A-G1-0lH1-41I3--J141-aK414-41Gs4H-1I--51k1J5A-515a H-I-1J16-LP166e Anin Ss ulaKA A-04 A-05 A-06 AZ0504 Z-05 Kilometers 175°W 170°W 165°W 160°W 155°W Figure 1. -- Grid map of sample stations for the 2010 eastern and northern Bering Sea continental shelf bottom trawl survey.