A survey of the fish fauna of Transkei estuaries. Part 1. The Kei River estuary

Abstract

The species composition, seasonal abundance and spatial distribution of the fish fauna of the Mtata estuary (8, 5 km long) was determined by means of gill nets. Nine hundred and ninety fish (462, 9 kg) comprising 26 species were caught of which M. cephalus (43, 3%), A. hololepidotus (18, 9%), P. commersonnii (7, 9%), E. machnata (7, 1%) and L. amia (5, 45) were most abundant in terms of biomass. Mullet species constituted 48, 3% of the biomass caught, representing 25, 6% of the numbers. Seasonal patterns were ascertained for M. cepha/us, M. capensis, V. buchanani, A. h%/epidotus, P. commersonnii, P. kaakan, E. machnata, L. amia, J. dussumieri, T. vitrirostris and L. equula. A mean of 19, 4 fish with a mean mass of 9, 1 kg were caught per net per station. Numerically the highest catches were made in the upper reaches; gravimetrically in the middle reaches. Temperatures ranged from 10, 5-25, 5°C; a salinity gradient was usually present in all reaches; oxygen levels and turbidities were high.