CRUSTACEAN COMMUNITY COMPOSITION AND TROPHIC USE OF THE DRIFT VEGETATION HABITAT BY JUVENILE SPLITNOSE ROCKFISH SEBASTES DIPLOPROA

The community composition and trophic use of the drift vegetation habi tat by pre-settlement juvenile splitnose rockfish Sebastes diploproa w as documented in June, August, and October 1992 in the San Juan Archip elago, Washington, USA. Fucus spp., Zostera spp. and Nereocystis luetk eana were the dominant vegetation for the months sampled. Juvenile S. diploproa collected from the drift vegetation habitat fed mainly on pl anktonic organisms, including copepods and cladocerans, during June an d August, In October, diets shifted to larger epiphytic prey and were dominated by 1 amphipod species. Of 5 major prey taxa, 3 had significa ntly different densities in drift vegetation and nearby open water hab itats. Prey taxa were not dominant in the drift vegetation habitat in June and August, indicating a high degree of prey selection during the se months. In October, dominant prey taxa made up a large proportion o f the crustacean community in the drift vegetation habitat and less pr ey selection occurred. Community indices of the drift vegetation habit at were up to twice as high as those of the adjacent open water habita t for the 3 mo sampled due to vegetation associated crustaceans. Drift vegetation provides nearshore habitat features to pelagic systems. It provides food, refuge, and possibly transport from offshore to nearsh ore habitats for a number of recreationally and commercially important species.