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Acoustic returns showing pollock schools. Scientists in the Midwater Assessment and Conservation Engineering (MACE) Program have historically assessed the status of walleye pollock and Pacific hake stocks from the coasts of California to the Bering Sea since 1977. The MACE Program continues to assess walleye pollock in the north Pacific and Bering Sea, while the Northwest Fisheries Science Center has continued Pacific hake assessments biennially since 2003. Pollock assessment is conducted with midwater trawl surveys combined with acoustic (echo integration) technology to develop distribution and abundance time series. Research is also conducted on fishing gear performance and on fish behavior during the capture process in order to develop methods that reduce bycatch in commercial fishing operations.

Twin trawl being brought on deck. Walleye pollock resources in the north Pacific and Bering Sea support the largest single commercial fishery in the United States and one of the largest commercial fisheries in the world. Surveys to determine the pollock abundance and distribution are conducted to support NMFS fishery management responsibilities for the territorial sea and to meet U.S. international fishery management commitments for the Convention on the Conservation and Management of Pollock in the Central Bering Sea.

Winter surveys of spawning pollock abundance have been conducted annually in the Bogoslof Island area of the Bering Sea since 1988 and in the Shelikof Strait area of the Gulf of Alaska since 1981. Assessment of summer pollock abundance in the Bering Sea has occurred routinely since 1979, while Pacific hake abundance off the West Coast was surveyed from 1977 to 2001. Pollock surveys continue to be conducted in conjunction with bottom trawl surveys for other groundfish species, and often carried out in cooperation with foreign scientists and foreign research vessels. The acoustic/midwater trawl survey estimates of distribution and abundance are documented in various scientific reports and are incorporated into stock assessment advice to fishery management councils, international fishery management organizations, and industry.

MACE researchers receive NOAA Bronze Medal Award

Seafloor Videos from Bering Sea Research Project

 

Recent Publications, Poster Presentations, Reports & Activities

  • Results of the echo integration-trawl survey of walleye pollock (Theragra chalcogramma) on the U.S. and Russian Bering Sea shelf in June and July 2008.
    HONKALEHTO, T., N. WILLIAMSON, D. JONES, A. McCARTHY, and D. McKELVEY. 2009. Results of the echo integration-trawl survey of walleye pollock (Theragra chalcogramma) on the U.S. and Russian Bering Sea shelf in June and July 2008. U. S. Dep. Commer., NOAA Tech. Memo., NMFS-AFSC-194, 56 p. (.pdf, 2 MB).  Online.
     
  • Do Silent Ships See More Fish? Comparisons of Walleye Pollock Backscatter Recorded by a Conventional and a Noise-Reduced Research Vessel in Alaska.
    ALEX De ROBERTIS, CHRISTOPHER D. WILSON, and NEAL J. WILLIAMSON 2008. Do Silent Ships See More Fish? Comparisons of Walleye Pollock Backscatter Recorded by a Conventional and a Noise-Reduced Research Vessel in Alaska. AFSC Quarterly Report Feature (October-November-December 2008) 6 p. (.pdf, 1.9MB).  Online.
     
  • Characterization and classification of acoustically detected fish spatial distributions.
    BURGOS, J. M., and J. K. HORNE. 2008. Characterization and classification of acoustically detected fish spatial distributions. ICES J. Mar. Sci. 65:1235-1247. 
     
  • Status review of the ribbon seal (Histriophoca fasciata).
    BOVENG, P. L., J. L. BENGTSON, T. W. BUCKLEY, M. F. CAMERON, S. P. DAHLE, B. A. MEGREY, J. E. OVERLAND, and N. J. WILLIAMSON. 2008. Status review of the ribbon seal (Histriophoca fasciata). U.S. Dep. Commer., NOAA Tech. Memo. NMFS-AFSC-191, 115 p. (.pdf, 4.78 MB).  Online.
     
  • Estimating Unobserved Mortality of Chionoecetes sp. Due to Encounters with Bottom Trawls
    By:  CRAIG S. ROSE, ALLAN W. STONER, LOVEDAY L. CONQUEST, CARWYN F. HAMMOND, J. ERIC MUNK, JOHN GAUVIN
    Conference:  Lowell Wakefield Fisheries Symposium (25th), Biology...Crab Populations under Climate Change..., Anchorage, AK, Mar 2009
    (2009 poster, .pdf, 802KB.)   Online.

     
  • Biogeography of Forage Fish in the Eastern Bering Sea
    By:  ANNE B. HOLLOWED, ED FARLEY, CHRIS WILSON, STAN KOTWICKI, NED COKELET
    Conference:  BEST-BSIERP Principal Investigator Meeting, Girdwood, AK, Oct 2008
    (2008 poster, .pdf, 661KB)   Online.

     


See the publications and poster databases for additional listings.

 

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