Scientists with the National Oceanic and Atmospheric Administration’s Alaska Fisheries Science Center have calculated the initial biomass estimates from the 2011 eastern Bering Sea survey. This is a big step in the annual process to set total allowable catch levels for various groundfish and crab species in the Bering Sea.
The biomass estimates from the 2011 bottom trawl survey for the selected species are 3.11 million metric tons of walleye pollock, 1.98 million metric tons of rock sole, 520 thousand metric tons of Alaska plaice, 26.2 thousand metric tons of Greenland turbot, 911 thousand metric tons of Pacific cod and 2.40 million metric tons of yellowfin sole,
There were slight decreases in the survey biomass of walleye pollock and rock sole compared to 2010 and slight increases for the survey biomass for the other four species.
Scientists also found that the mean bottom temperatures on the eastern Bering Sea shelf were generally higher in 2011 compared to 2010, and the cold pool during the late spring and early summer sampling period was significantly reduced in size.
The North Pacific Fishery Management Council’s Groundfish Plan Team will begin their review and incorporation of the survey data in the scientific stock assessments at their November meeting and will provide reports to the Council’s Scientific and Statistical Committee. The SSC will recommend acceptable biological catch for the different species at the December council meeting in Anchorage. The council’s advisory panel will then recommend a total allowable catch for each of the species. Following the committee reports, the council will consider committee recommendations and public testimony before recommending a total allowable catch for the various groundfish species in 2012.
The 2011 eastern Bering Sea survey results for crab are currently being reviewed by the NPFMC Crab Plan Team at their September meeting at the Alaska Fisheries Science Center.
The survey was conducted aboard the chartered fishing vessels Aldebaran and Alaska Knight. The vessels bottom trawled at 376 stations over a survey area of 144,600 square nautical miles, finishing the survey August 4.
The science crew processed and recorded the catch from each trawl catch by identifying, sorting and weighing all the different crab and groundfish species and then measuring samples of each species. They then validated the data collected on fishing effort, catch rates and biological characteristics of the fish populations in preparation to generate fishery-independent estimates of geographic and depth distribution, abundance, and population size and age compositions of the various species.