Movement behaviour of the Green Jobfish (Aprion virescens), the Potato Bass (Epinephelus tukula) and the Giant Trevally (Caranx ignobilis), on South Africa's coral reefs

The movement behaviour of three important reef fish predators, namely potato bass (Epinephelus tukula), green jobfish (Aprion virescens) and giant trevally (Caranx ignobilis), were studied to provide information for marine spatial planning and to understand their ecological roles on South Africa's coral reefs. The three species were expected to display contrasting movement behaviour and to place different demands on spatial management strategies. The three species of coral reef meso-predators, potato bass (n=35), green jobfish (n=38) and giant trevally (n=9) were tagged with acoustic transmitters and released within a widespread receiver array (n=46) spanning approximately 306 km of coastline, which included the iSimangaliso Wetland Park (IWP), South Africa, and Ponta do Ouro Partial Marine Reserve (PPMR), Mozambique. The resulting telemetry data were used to investigate (1) the extent of their movements, (2) temporal patterns of movement, and (3) movements and connectivity between different management zones within the IWP, South Africa's largest coastal marine protected area. An analysis of 892 552 detections over a period of six and a half years, using a novel residency index, showed that green jobfish and potato bass exhibit high site fidelity with residency index values ranging from 61.6 to 100 % (mean = 85.2 %) for green jobfish and from 87.3 to 99.9 % (mean = 95.0 %) for potato bass. Individual green jobfish and potato bass were detected at a similar number of receivers (mean 3 [± 0.4] and 3.3 [± 0.8]), respectively. In contrast, giant trevally had lower site fidelity with residency index values ranging from 49.4 to 92.3 % (mean = 66.9 %) and undertook frequent but temporally predictable long-distance migrations (mean maximum dispersal distance = 189.00 km [± 40.3]), often returning to their home range. On average individual giant trevally were detected on 13.8 (± 1.5) receivers. Previous literature showed variable temporal patterns of movement for green jobfish although the results of this study showed no ...