Home range of an estuarine-dependent fish species Pomadasys commersonnii in a South African estuary

The home range and area use of spotted grunter, Pomadasys commersonnii (Haemulidae) (Lacepede), were investigated in the Great Fish estuary, South Africa. Forty individuals (263-698 mm TL) were surgically implanted with acoustic-coded transmitters and manually tracked during two periods in 2003. Tagged fish spent on average 68 and 77% of the time in the estuary and the remaining time at sea during the two periods, respectively. While in the estuary, there was large variation in home range size, home range length and the number of home range areas amongst individuals. Larger fish had larger home ranges and more core areas than smaller fish. The home ranges of 29 individuals (74%) occurred in the lower reaches of the estuary, suggesting that the proclamation of a no-take zone in this high use area could benefit this over-exploited estuarine fishery species.