ABUNDANCE, POPULATION-STRUCTURE AND SIZE AT MATURITY OF SCYLLA-SERRATA (FORSKAL) (DECAPODA, PORTUNIDAE) IN EASTERN CAPE ESTUARIES, SOUTH-AFRICA

Catch per unit effort (CPUE), population structure and size at sexual maturity of the mud crab, Scylla serrata, was determined in 18 Eastern Cape estuaries between 1991 and 1994. CPUE and size composition of cr abs varied considerably among estuaries as well as annually within the same estuary, probably as a result of the erratic recruitment of larv al S. serrata into the estuaries from marine spawning grounds. The abu ndance of S. serrata in Eastern Cape estuaries appears to be too low a nd too variable to support a commercial fishery, but there is scope fo r harvesting by recreational, artisanal and subsistence fishermen in y ears when crabs are abundant. Female crabs mature between 130 and 140 mm carapace width (CW); some male crabs between 120 and 130 mm CW were capable of mating. Crabs in KwaZulu-Natal mature at a smaller size th an those in the Eastern Cape and different minimum size limits will be needed to protect spawning stocks in the two regions.