The fish assemblages within four habitats found in the nearshore waters of St John, United States Virgin Islands: with some insights into the nature of trap fishingt

Wolff, Nicholas

There has been increasing evidence of declining fisheries resources within Virgin Islands National Park, St. John, USVI. This has been demonstrated by reduced catches, a decline in average size of some species, and a shift in catch composition from more desirable food species to less valued species. Data suggests that the trap fishery, which continues within park boundaries, is partially responsible for these changes. In response to evidence of declining resources, Virgin Islands National Park initiated a fisheries project in 1992. This investigation is a component of the fisheries project. The primary objectives were to evaluate the relationship between measured habitat variables and fish assemblages, and to evaluate the relationship between these same habitat variables and trap catch; this information is needed to shed light on the nature of trap exploitation, and to assess which habitats and which fishes might be most vulnerable to overfishing. The fish assemblages from four distinct habitats, coral reef, gorgonian (soft coral), rocky reef(subtidal bedrock) and seagrass, were compared using two sample methods; a visual point census and fish traps (similar to those used by local fishermen). A total of seven sites, in two bays (one with extensive seagrass (Rendezvous Bay) and one without (Cinnamon Bay)), were sampled from February 1994 through December 1994. Measurements of total topographic heterogeneity (rugosity), live scleractinian coral cover, and gorgonian cover were also recorded at each site. It was predicted that fish abundance and species richness, as determined from visual censuses, would correlate positively with rugosity and live coral cover (assumed to be proxies for fish shelter). In contrast, it was predicted that trap catch (CPUE) would negatively correlate with rugosity and live coral cover. It was hypothesized that fishes would be more attracted to the shelter provided by... (missing page)