Changes in life history and ecological characteristics of coral reef fish catch composition with increasing fishery management

Abstract

Abstract  Length, life history and ecological characteristics of landed fish communities were studied over a 10-year period to test theories of fishing disturbance during a time of increased gear and closure management in heavily utilised fisheries. It was predicted that with greater management restrictions: (1) the earliest and fastest responses in the fishery will be seen in those species with faster turnovers, or relatively lower vulnerabilities to fishing; (2) the fishery would transition to a landed catch with higher mean trophic levels, and greater mean body lengths. In addition, the removal of a non-selective, small-mesh seine nets should benefit the catch of gears that previously had the greatest species selectivity overlap with the seine net. Many predictions were supported, although maximum lengths and lengths at maturity responded more rapidly than anticipated. The response to eliminating the non-selective seine net was a more rapid increase in sizes caught by gears with a larger overlap in size (hook and lines) than species selectivity (gill nets). The simultaneous comparison of management systems over time indicates that open-access fishing grounds can benefit from restrictions imposed in adjacent fishing grounds. The study indicated that multi-species coral reef fisheries management objectives of maximising yields, as well as maintaining the fish community's life-history diversity, require management trade-offs that balance local socio-economic and biodiversity needs.