COMPOSITION, ABUNDANCE AND SEASONALITY OF LARVAL FISH IN RICHARDS BAY HARBOUR, KWAZULU-NATAL, SOUTH AFRICA

Abstract

Summary The present study examined the composition, abundance and seasonality of fish larvae occurring in Richards Bay Harbour, over an 18-month period from June 1991 to November 1992. Ichthyoplankton samples were collected every six weeks at top, mid and bottom depths in the dredged channel 100 to 200 m from the harbour entrance. A total of 7 163 fish larvae, representing 105 taxa and 53 families, was collected throughout the study period. The dominant families were the Engraulidae and Gobiidae representing 50% and 37% of the total catch, respectively. The most abundant larvae were those of the thorny anchovy, Stolephorus holodon, and an unidentified goby, Gobiid 12 (32% and 30% of the total catch, respectively). Estuarine-associated taxa dominated the total catch in terms of density (61%), with 11 out of the 28 taxa being totally dependent on estuaries at some stage in their life cycle. Turbidity and temperature were significant variables accounting for 27% of the variation in larval densities of estuar...