Annual occupation pattern of temperate rocky reefs by the Argentine sandperch Pseudopercis semifasciata in San José Gulf Marine Park, Argentina

Abstract

The Argentine sandperch, Pseudopercis semifasciata (Cuvier), is the target of unregulated recreational and artisanal fisheries within the northern Patagonian gulfs of Argentina. Being a reef species, the applicability of conventional large-scale assessment and management approaches appear limited. A more suitable alternative might be offered by spatial approaches, but their effectiveness would depend on the species'degree of mobility. Underwater visual censuses were used to study the annual occupation pattern of shallow rocky reefs by P. semifasciata to evaluate the possible occurrence of spawning migrations and the potential of reserves to protect the stocks. The abundance of P. semifasciata was greatest in winter, intermediate in autumn and lowest in spring and summer, but densities were relatively stable and oscillated ±17-31% around the overall mean for each reef. There was no evidence of spawning migrations as no demographic changes were observed throughout the year. Young sandperches (<1year old) were never observed on the reefs. Implications of the results for the management of this species are discussed.