Angling pressure impedes a three-year telemetry study on mulloway (Argyrosomus japonicas) in a western Victorian estuary, Southern Australia

Abstract Mulloway (Argyrosomus japonicas) are widely distributed in estuarine and nearshore waters within the Indian and Pacific Oceans. In Australia, it is an iconic recreational species that is also important commercially, with the largest commercial fishery being in the Murray River estuary and nearby coastal environments. To determine habitat preferences and movements between the estuary and the open ocean, 24 mulloway were acoustically tagged and followed for three years. Tagged fish were tracked using 20 receivers deployed along the estuary from its mouth to 65 km upstream. However, during the study thirteen (54%) of the tagged mulloway were caught and kept by anglers, hampering analysis of mulloway movements but providing opportunistic data on angling pressure and sizes of captured fish. Although generalised movement patterns could be gleaned from the remaining data, this case study exemplifies the challenges of telemetric studies of intensively angled fishes in estuaries and other semi-enclosed waters.