Ichthyoplankton of the continental shelf near Kodiak Island, Alaska

Abstract

Eleven ichthyoplankton surveys were conducted (1 in 1972 and 10 between 1977 and 1979) in the northeastern Pacific Ocean over the continental shelf off Kodiak Island, Alaska. In the 677 neuston and 632 bongo tows, eggs or larvae of more than 80 fish taxa were found. They were present in every season and throughout the survey area, although more taxa and more individuals were found in summer than in other seasons. Among the more abundant species were the gadid Theragra chalcogramma and several hexagrammids and pleuronectids. The hexagrammids and several coUids were abundant in the neustonic layer, where they spent close to a year as larvae and prejuvenlles. Although the seasonal and geographic distribution of most taxa was complex, two patterns emerged: Late summer-fall spawners produce demersal eggs and have neustonic larvae that remain pelagicfor several months (hexagrammids and some cottlds), and spring-summer spawners have pelagic eggs and larvaethat spend several weeks in the plankton but are not closely associated with the surface (Theragra chalcogramma,pleuronectlds). (PDF file contains 95 pages.)