Inshore small-mesh trawling survey of the Cape south coast. Part 2. Occurrence of estuarine-associated fishes

Abstract

Marine inshore trawl catches of 12 species of estuarineassociated fishes are reported together with their depth and length distributions. Underwater observations of four additional species, made during 122 SCUBA dives over rocky substrates, are also recorded. Species include Rhabdosargus holubi, R. globiceps, Pomadasys commersonii, Argyrosomus hololepidotus, Pomatomus saltatrix, Galeichthys sp. and Sarpa salpa. The data are related to published accounts of the occurrence of juveniles of estuarine-associated and inshore species in the Cape south coast region. This revealed three ecologically distinct groups of inshore fishes: typically marine species that only use marine inshore nursery grounds; an intermediate group that uses mainly marine inshore nurseries plus estuarine nurseries to a limited extent; and a specialized group that is dependent on estuarine nurseries. Possible reasons for this dependence on estuaries are suggested.