Changes in species composition of the demersal fish community in nearshorewaters of Kodiak Island, Alaska

We examined the species composition of the demersal fish and shrimp communi ty in seven different areas in the nearshore waters of Kodiak Island based on trawl survey data. A major part of the variability in the data set was a ttributed to trends over time, indicating a significant change in species c omposition in the early 1980s. Results agree with work by others and show a shift from a community dominated by shrimp and small forage fishes to one dominated by large piscivorous gadid and flatfish species. The shift occurr ed rather abruptly in most areas between 1980 and 1982, but the pattern of change differed significantly among areas. Correlations between trends in t he two groups of species were weak but were consistent with the hypothesis that the decline in shrimp and forage fishes followed, rather than preceded , the increase in large piscivorous fishes. The results suggest predation a s a possible mechanism to explain the observed changes.