FY 2005

Relationship of age-0 pollock abundance and distribution around the Pribilof Islands, to other shelf regions of the eastern Bering Sea

Swartzman, G., A. Winter, K. Coyle, R. Brodeur, T. Buckley, L. Ciannelli, G. Hunt, J. Ianelli, and A. Macklin

Fish. Res., 74(1–3), 273–287, doi: 10.1016/j.fishres.2005.01.023 (2005)

The Pribilof Islands region is recognized to be a major nursery for age-0 walleye pollock (Theragra chalcogramma) in the eastern Bering Sea. However, the Pribilof Islands’ importance for the recruitment of pollock in the Bering Sea has not been quantified. In this paper, we define the geographic extent of the Pribilof Islands region based on ocean circulation, location of major fronts, and trophic interactions. The abundance and distribution by oceanographic habitat (nearshore, frontal and offshore), of acoustically determined age-0 pollock are compared between the Pribilof Islands and the Inner Front of the eastern Bering Sea, for the summers of 1997–1999. Net samples collected during surveys in 1995–2002 are used to compare the abundance of age-0 pollock in the Pribilof Islands region to locations eastward along the Bering Sea shelf.

We found densities of age-0 pollock near the Pribilof Islands to be generally higher than on the surrounding shelf, and higher or non-significantly different from the Inner Front. Through synthesis of our data and inferences of pollock growth and mortality, we estimate the Pribilof Islands region to have comprised 12.5% (1997), 53.7% (1998), and 24.7% (1999) of the total stock of age-0 pollock in the eastern Bering Sea. Since the Pribilof Islands region comprises only 14% of the total eastern Bering Sea area, evidence is given that a disproportionally large fraction of the age-0 pollock population inhabits the Pribilof Islands nursery.