Beyond the hook: do angler-fish interactions in a catch-and-release recreational fishery modify fish space use and catchability?

By combining acoustic telemetry, mark-and-recapture, and location-specific catch logs, we tested whether angler-fish interactions altered the behavior, space use, and catchability of giant trevally ( Caranx ignobilis) (GT) in coastal waters of the Alphonse Island Group, Seychelles, Indian Ocean. Adult GT near a high human use area with limited provisioning showed restricted movements during the tourism fishing season and had home ranges nearly 50% smaller than that of adult GT from other parts of the atoll group. Despite angler catch maps overlapping with 30% of non-habituated adult GT core use areas, recaptures were infrequent, suggesting that GT became hook shy. Although there was no change in movement patterns during a temporary fishing closure caused by COVID-19, non-habituated GT movement patterns shifted toward wider ranging movements with each successive fishing season, potentially to avoid shallow water areas where angler activities occurred. Our findings highlight how angler interactions and catch-and-release fisheries have the potential to modify the behavior, space use, and catchability of targeted species, and may influence the viability of the fishery by exceeding its capacity.