NOAA Fisheries News Releases
September 18, 2009
Sheela McLean, Public Affairs
NOAA releases results of 2009 pollock surveys
NOAA fisheries researchers have released scientific data from their 2009 bottom trawl and mid-water acoustic surveys of pollock in the Bering Sea. One survey index is lower than expected based on the 2008 population analysis while the other is higher. The 2009 surveys confirm that the population is low and indicate that the number of incoming young fish may be down also.
"The pollock spawning biomass was well above average for a decade starting in 1993 but has since declined to below target levels," said Doug DeMaster, Director of NOAA's Alaska Fisheries Science Center. "Fewer young fish entered the population between 2001 and 2005. The new data confirm this pattern and will provide additional information on the numbers of new fish entering the fishable population."
"Our surveys provide estimates of the upcoming population numbers before the pollock are large enough to be caught by fishermen. This allows managers to make timely conservation decisions," DeMaster added.
NOAA scientists this week presented the 2009 pollock survey data to the North Pacific Fishery Management Council's Groundfish Plan Team, which begins reviewing scientific stock assessments in September. With stock assessment reports in hand, the Council's Scientific and Statistical Committee will recommend an acceptable biological catch level — a sustainable catch level — at the December Council meeting in Anchorage. The Council's Advisory Panel will then recommend a total allowable catch. Following the committee reports, the Council will consider committee recommendations and public testimony before recommending a total allowable catch for pollock for 2010.
The previous assessment indicated that the estimated 2008 spawning biomass (the main stock component monitored for conservation purposes) was at the lowest level since 1980. Managers reduced the total allowable catch to 815,000 metric tons for 2009. That is a 46% reduction from the 2006 total allowable catch.
"The decreased biomass appears to be a cyclical fluctuation and is not a result of overfishing, which has caused problems in other fisheries worldwide," said DeMaster.
The Alaska pollock fishery is the largest fishery, by volume, in the United States. It is known for its strong management, conservative catch levels, near real-time reporting and scientific fishery observers who track catch levels and closely monitor accidental bycatch of other marine species. The fishery uses pelagic trawls which minimize disturbance of the bottom habitat. The pollock fishery has a very low bycatch rate, averaging one and a half percent by weight.
Researchers use bottom trawls to survey groundfish (including pollock) and crab plus an acoustic-trawl survey for pelagic walleye pollock. The annual bottom trawl survey of the eastern Bering Sea continental shelf began in 1971. This year the fishing vessels Aldebaran and Arcturus, chartered from May 28 to August 2, sampled 376 trawl stations over an area of 144,600 square nautical miles. Researchers processed and recorded the data from each trawl catch by identifying, sorting, and weighing all the different crab and groundfish species. Biological samples for diet, age, growth, and maturity are then taken for the different species.
Researchers ran the acoustic-trawl survey of walleye pollock in the Bering Sea between June 9 and August 7 from the NOAA ship Oscar Dyson. The 2009 acoustic trawl survey is the latest in a series that began in 1979. This year the survey covered the area from Bristol Bay to the western Bering Sea shelf region extending into the Russian Exclusive Economic Zone.
NOAA understands and predicts changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources. Visit www.noaa.gov. To learn more about NOAA Fisheries in Alaska, visit alaskafisheries.noaa.gov or: www.afsc.noaa.gov.