Assessment of the impact of commercial beach-seine netting on juvenile teleost populations in the surf zone of False Bay, South Africa

Abstract

A total of 311 commercial beach-seine hauls monitored in False Bay between January 1991 and December 1992 yielded 38 930 juvenile teleosts from 31 species and 18 families. Eight teleost species important in anglers' catches in the South-Western Cape together provided nearly 60% of the total juvenile catch, of which Rhabdosargus globiceps (22,8%) and Pomatomus saltatrix (20,3%) were the most abundant. Mean juvenile catch per haul for all species was 125 individuals, mean annual catches of juvenile teleosts so amounting to approximately 74 000 individuals. Juvenile teleosts constitute <6% of the total beach-seine catch in False Bay, considerably smaller than the proportion of juveniles in other South African commercial and recreational fisheries. When compared to published estimates of natural mortality for juvenile teleosts frequenting nearshore sandy beach habitats, potential seine-net mortality was calculated to be insignificant for most of the species considered. However, estimated annual catches of juv...