Populations in the eastern and western Bering Sea and Aleutian Basin have also been managed separately. Such management strategies may be falling short if, as Bentzen and others suspect, distinct populations of pollock exist on much finer scales. However the degree of intermingling of these stocks, the recolonization of depleted areas by existing stocks, and other ecological questions about mixing within the greater population framework are almost completely unknown. Hundreds of individual DNA samples from six walleye pollock stocks are kept in glass tubes at the Marine Molecular Biotechnology Laboratory. Trouble in Pollock Paradise Pollock stocks in Japan and Puget Sound have dwindled considerably in recent years.
Experts are at a loss to explain the decline.
The National Marine Fisheries Service is considering the Puget Sound pollock stock as a candidate for protection under the federal Endangered Species Act. Ten years ago, you could go out on a charter fishing boat from Tacoma and catch 30 pollock in an hour, says NOAA's Kevin Bailey. Today if you revisited the same area, you wouldn't catch a single fish. It's possible that fishing pressure, which typically depletes the larger, adult specimens, may have been a factor in the Puget Sound pollocks' disappearance, according to Bailey. In contrast, Bering Sea populations remain relatively healthy, says Bailey.