The effects of marine protected areas on populations of commercial reef fishes in Moorea, French Polynesia

Abstract

While marine protected areas (MPAs) have been internationally recognized as an effective resource management technique, many MPAs worldwide are not fulfilling their conservation goals and are under review: as is the case in Moorea, French Polynesia. Although a system of 8 MPAs has been in effect for ~15 years on the island, adherence of fishers to the boundaries and public support for the current management plan (PGEM) is spotty. This study uses underwater surveys of 9 taxa of reef fish to evaluate how effective fishing restrictions in Moorea, French Polynesia are for conserving populations of commonly targeted fish in the backreef habitat. The current study investigates the effectiveness of Moorea's MPAs on conserving populations of commercial reef fish by measuring abundance and size structure of commonly targeted fish just in 2019, and long-term biomass monitoring data from 2004 through 2018. There were increases in commercial reef fish abundance in MPAs for most taxa and there were differences in size distributions for 3 of the taxa between MPAs and fished control sites in 2019. Generally, more individuals of larger size classes were present in MPA sites compared to fished control sites. However, time series data from the last 15 years revealed no significant increases in harvested fish biomass in protected areas relative to fished control sites in the backreef habitat. Increased efforts in policy enforcement, community awareness, and biological monitoring are required at Moorea's MPAs and others worldwide to ensure protected areas truly are effective.