The recreational fishery in the Kosi estuarine lake system, South Africa

Abstract

The Kosi estuarine system, located in northern KwaZulu-Natal, is becoming an increasingly popular angling venue. Recreational catch card data from the National Marine Linefish System for the years 1986 to 1999 were analysed to determine total catch, catch composition, catch per unit effort (CPUE), seasonality of catches and annual trends in catch composition. A total of 17 families, comprising 34 species, was reported in catches of recreational anglers. Pomadasys spp., predominantly Pomadasys commersonnii, was the most prominent taxon caught in terms of both numbers and mass. Seasonal trends in catch rates were observed, with more fish caught in the summer and autumn months. The catch rate fluctuated annually. Fluctuations in CPUE were closely correlated to the number of cards collected, which reflects bias in the data. Despite annual fluctuations in CPUE, regression analysis revealed a slight increase in overall CPUE with time. However, CPUE for Acanthopagrus berda and Lutjanus  argentimaculatus decreased steadily since 1986. The decline of these two estuarine-dependent species may indicate that the total fishing levels are not sustainable.

Key words: angling, catch composition, catch per unit effort.