Fisheries harvest and standing stock in a Hawaiian Bay

Abstract

An 18-month study at Hanalei Bay, Kauai provided unusually valuable quantitative fishery data and concurrent estimates of natural density of reef fish for a complete, small, subsistence/recreational/artisanal fishery on a small, remote island in the tropical mid-Pacific. Catch and effort data were collected using a stratified random sampling design. The commercial surround net fishery targeted mainly coastal pelagic species and accounted for over 70% of the catch. Most other fishing was for recreation or subsistence. Line fishing from shore and boats accounted for much of the effort but produced some of the lowest catches per unit effort (CPUE). The cast net and spear fisheries had CPUE values of more than 1 kg per gear-hour and caught a wide diversity of reef-associated species. Standing stock of reef-associated fishes was estimated from 516 underwater visual censuses. Mean biomass ranged from over 16 kg/100 m 2 in shallow complex habitats to less than 1 kg/100 m 2 in monotypic reef flat habitats. These densities, which are higher than those reported from some more populated, similar areas in Hawaii, may reflect lower fishing pressure in Hanalei. Yield estimates from Hanalei Bay are very low compared to those from many other locations in the Pacific. The small fraction of the overall standing stock that is harvested annually (~ 1.3%) suggests that most of the fish community is not being severely overfished. Parrotfishes, goatfishes, and surgeonfishes were important components of the fisheries and of the censused communities, suggesting that these target species have not been seriously depleted. The small sizes at which some valued species are caught is a matter of concern for management of these stocks.