Baited Remote Underwater Video Reveals Low Abundances Of Sharks Across The Philippines But Marine Protected Areas Offer Respite

Exploitive and unsustainable fishing practises are having deleterious effects on marine resources worldwide. Members of the order Chondrichthyes are particularly susceptible to overharvesting as a result of k-selected life... [ view full abstract ]

Exploitive and unsustainable fishing practises are having deleterious effects on marine resources worldwide. Members of the order Chondrichthyes are particularly susceptible to overharvesting as a result of k-selected life history traits rendering slow population recovery. The Philippines is a biodiversity hotspot for sharks and rays yet the country remains a data-poor region for many species. To address this urgent knowledge gap, we investigated the abundance, biodiversity and distribution of elasmobranchs in nine locations using Baited Remote Underwater Video (BRUV), a non-invasive and increasingly popular monitoring tool in marine ecosystems. We also evaluated the performance of two Marine Protected Areas (MPAs), Apo Reef Natural Park and Tubbataha Reefs Natural Park against Open Fishing Zones (OFZ) in sustaining populations of Reef Associated Sharks (RAS). The surveys recorded 301 sharks and rays from 18 species across all study locations. Our results demonstrate that MPAs support significantly higher abundances of RAS when compared with OFZ, where sharks were either absent or occurred only in low abundances. We hypothesize that RAS populations are highly exploited in the Philippines and these results further highlight the crucial role of MPAs for their conservation.