Alaska Pollock is one of the largest sustainable fisheries in the world and is divided in to two stocks, the Bering Sea/Aleutian Island stock and the Gulf of Alaska stock. The Eastern Bering Sea fishery is the largest by volume in the United States with annual total allowable catches of 1.3 million tons. From 1977-2011 the average catch from the eastern Bering Sea was 1.17 million tons. From 2012-2014 the catch of eastern Bering Sea Pollock increased to an average of 1.26 million tons. The Gulf of Alaska stock is much smaller than the eastern Bering Sea stock. Over the last two decades there have been relatively low abundance of Pollock in the Gulf of Alaska, but the population appears to be stable .
Harvesting: Fishing methods for the eastern Bering Sea consist of catcher/processor vessels that process their catch at sea and trawl catchers that transport their catch onshore for processing . 90% of the fish caught from the Gulf of Alaska are done by pelagic trawl. Products that are made from Pollock were valued at $1 billion; products include surimi, fish meal, fillets, deep skin fillets, and roe.
NOAA: Pollock biomass up 60% in Bering Sea: https://www.undercurrentnews.com/2014/09/24/noaa-pollock-biomass-up-60/
Walleye Pollock species page: https://www.fishwatch.gov/seafood_profiles/species/pollock/species_pages/alaska_pollock.htm
Walleye Pollock facts sheet: https://www.afsc.noaa.gov/Education/factsheets/10_Wpoll_FS.pdf
Marine Stewardship Council: