An integrated baseline assessment of reef-associated sharks around Saba (Dutch Caribbean), combining three methods: stereo-BRUVs, telemetry and citizen science

The Exclusive Economic Zone of Saba (Dutch Windward Islands) has been designated Yarari Marine Mammal and Shark Sanctuary. However, to effectively conserve sharks, a baseline on their diversity and spatiotemporal distribution is required. We used three methods: telemetry, stereo-baited remote underwater video systems (stereo-BRUVs) and a citizen science program to study reef-associated sharks, mainly Caribbean reef sharks (<i>Carcharhinus perezi</i>) and nurse sharks (<i>Ginglymostoma cirratum</i>) around Saba during 2012-2020. Based on the stereo-BRUVs, we determined that the presence of Caribbean reef sharks (0.25 ± 0.48 maxN h^-1; mean ± s.d.) and nurse sharks (0.20 ± 0.45 maxN h^-1) was relatively high compared to other Caribbean coral reef systems. With telemetry, we showed that the residence and fidelity of Caribbean reef sharks were high, especially for immature individuals. In addition, we showed a higher presence of Caribbean reef sharks during December-May and a lower overall presence of adult males. The citizen science program showed an increase in observations of both species between 2012 and 2020, possibly indicating an increase in abundance or a change in shark behaviour related to the culling of exotic lionfish. We demonstrate that these three methods can be used complementary to provide a baseline of the diversity and spatiotemporal presence of reef-associated sharks.