Temporal and geographic differences in feeding and nutritional condition of walleye pollock larvae Theragra chalcogramma in Shelikof Strait, Gulf of Alaska

Abstract

Feeding and nutritional condition of first-feeding walleye pollock larvae Theragra chalcogramma were compared to available prey levels measured during early spring (late April-early May) and mid-spring (mid-May) 1989. In early spring, feeding intensity, mean RNNDNA values of larvae, and microzooplankton abundance were higher within a large patch of larvae compared with areas outside the patch. In mid-spring, microzooplankton prey abundance, feedmg levels and RNA/DNA of larvae m and out of the previously defined patch were higher, indicating better overall conditions for growth than in early spring. The results suggest that limiting food densities may occur during spring over spatial and temporal scales that affect feeding and growth of larval pollock.