A synthesis of biological and physical processes affecting the feeding environment of larval walleye pollock (Theragra chalcogramma) in the eastern Bering Sea

Biological and physical phenomena that affect conditions for larval surviva l and eventual recruitment differ in the oceanic and shelf regions. In the oceanic region, eddies are a common feature. While their genesis is not wel l known, eddies have unique biophysical characteristics and occur with such regularity that they likely affect larval survival. High concentrations of larval pollock often are associated with eddies. Some eddies are transport ed onto the shelf, thereby providing larvae to the Outer Shelf Domain. Adve ction, rather than local production, dominated the observed springtime incr ease in chlorophyll (often a correlate of larval food) in the oceanic regio n. Over two-thirds of the south-eastern shelf, eddies are absent and other phenomena are important. Sea ice is a feature of the shelf region: its inte rannual variability (time of arrival, persistence, and areal extent) affect s developmental rate of larvae, timing of the phytoplankton bloom (and pote ntially the match/mismatch of larvae and prey), and abundance and distribut ion of juvenile pollock. In the oceanic region, interannual variation in fo od for first-feeding pollock larvae is determined by advection; in the shel f region, it is the coupled dynamics of the atmosphere-ice-ocean system.