Abundance and distribution patterns of intertidal fishes at three sites within Redwood National and State Parks, 2004-2005

The tidepool fishes of Redwood National and State Parks, California were sampled to access the community structure of intertidal fishes in this under-studied region. A total of 13 samplings, at three sites, took place from March 2004 to September 2005. Combined collections, at three rocky intertidal sites, yielded approximately 5,000 fish comprising 26 species from 11 families. The sites examined for this study, Enderts Beach, Damnation Creek, and False Klamath Cove, differed in both species richness and diversity. The sites also differed in habitat factors and tidepool characteristics. Damnation Creek, the larger, more heterogeneous habitat yielded the greatest number of fish species. False Klamath Cove, dominated by boulder substrate, had a greater number of species that are commonly associated with boulder substrata, including juvenile rockfish. Enderts Beach, the smallest area sampled, is surrounded by sandy beach which is unsuitable for most fish species. Although this site had the fewest species, fish abundances were more than double those of the other sites. Overall, patterns of fish abundances were driven largely by the family, Cottidae, which comprised 88% of the total fish sampled. Species diversity did not differ significantly over the time period sampled, although a greater abundance of fish and more species were found in summer compared to winter. This seasonal increase was in part due to the recruitment of young cottids and the presence of summer seasonal species, such as juvenile black rockfish, Sebastes melanops. Mark-recapture methods suggested that tidepool sculpins exhibit high site fidelity. Of 1,399 marked sculpins, 309 out of the 314 recaptures were found in the pool of original collection. Habitat assessment showed that the three sites varied with regard to tidepool characteristics and patterns of fish abundances. Habitat-species relationships were examined and showed evidence of niche partitioning among some fish species, especially between the congeners Oligocottus maculosus and O. snyderi.