Large-scale movements and site fidelity of two bull sharks <i>Carcharhinus leucas</i> estimated from a double-tagging experiment at Réunion Island (southwest Indian Ocean)

Since 2011, the mean number of bites per year by bull sharks Carcharhinus leucas has increased markedly at Réunion Island. To predict areas and periods risk, we need to better understand space-use dynamics individual sharks. In coastal waters off Island, two sharks, one each sex, were double-tagged tracked for 174 days (male) 139 (female) using pop-up satellite archival tags (PSATs) acoustic transmitters. Both spent most their time inshore (58.1% male 89.9% female). The female performed short excursions but typically remained inshore. alternated between spending residence along coast undertaking wide-ranging movements, including extensive open-ocean excursion vicinity a seamount situated about 210 km from island. Differences in residency home range probably reflect different patterns foraging mating behaviours. Our results highlight advantages double-tagging telemetry studies that attempt estimate degree habitat fidelity species illustrate consider movement scales when developing efficient risk-mitigation management.