Ensuring the Sustainability of Coastal Small-Scale Fisheries at Pitcairn Island (South Pacific) Within a Large Scale No-Take MPA

The Pitcairn Islands, located in the central South Pacific, contains near-pristine marine ecosystems which support unique fish assemblages, and contain both endemic and threatened species. Pitcairn itself is the only inhabited island in the group, and before this study, the environmental impact of local fisheries was unclear, with little data to inform conservation and management. In 2014-2015 near-shore fish populations were assessed through mixed methods: a newly introduced system of fishers' catch monitoring and Baited Remote Underwater Video Systems (BRUVS). Thirty-nine BRUVS deployments recorded 88 species in total, with small-bodied herbivores (e.g. Kyphosus pacificus) and mesopredators (e.g. Xanthichthys mento) dominating a ‘bottom heavy’ assemblage. Several large pelagic predators were recorded, but reef-associated predators were rare with only one shark observed. Pitcairn’s top predator assemblage was demonstrably impoverished compared to global ‘pristine’ sites, including other islands within the Pitcairn group. Top predator scarcity may be explained by local artisanal fisheries, which have historically targeted sharks and other large predators, while recent fishing pressure declines may explain observed proliferations of small-bodied species which have filled the niche left by over-harvesting of larger taxa. Subsequent to BRUVS sampling, a local fisheries officer post was created to collate catch data from nearshore fishers. Regular returns were obtained from over half of the active fishers (representing approximately 80% of catches), with K. pacificus also dominating catches and the small grouper Epinephelus fasciatus frequently targeted. Thirty fish species were represented in the recorded catch over a 12 month period. Results were shared with the local community, providing a basis for the cooperative design of a Fisheries Management Plan. This plan ensured traditional fisheries could continue in a sustainable manner within Coastal Conservation Zones around each of the four Pitcairn Islands, established within the large, no-take Marine Protected Area designated in 2016, covering the entire Pitcairn Exclusive Economic Zone. Monitoring of Pitcairn’s artisanal fisheries should be continued beyond this one-off study in order to inform adjustment of the Fisheries Management Plan, as the ongoing island fishery may still have consequences for long-term sustainability, particularly for pelagic species caught in nearshore waters which remain a significant data gap.