Effects of small, Fijian community-based marine protected areas on exploited reef fishes

Abstract

No-take marine protected areas (MPAs) are commonly applied in community-based management schemes to sustain and enhance coral-reef fisheries. However, many MPAs in Fiji and the South Pacific are relatively small (641 km2), and few data exist regarding the effects of these MPAs on populations of exploited species. We used hook-and-line fishing surveys to assess whether 4 relatively small (<1 km2) community-based MPAs in Fiji (3 current, 1 former) were providing any commonly sought benefits to exploited reef-fish stocks. All of the MPAs had maintained no-take status for over 4 yr, although the former MPA was opened to fishing 4 mo before this study. The current MPAs exhibited significantly greater catch and biomass per unit effort, individual fish biomass, and/or percentage of reproductive-size fish than paired, adjacent fished areas, while this was not the case with the former MPA. Sites with intact MPAs also exhibited greater catch diversity than the former MPA site. Additionally, tag and recapture data from the 17 recaptured of 2650 tagged fish suggest site fidelity of these fishes, although fishes initially captured in the MPA at all 4 sites were later caught in fished areas, indicating that there is movement of fishes from the MPAs to fished areas. While the combination of these findings supports the utility of even relatively small MPAs as effective tools for the conservation of certain target species, it also suggests that MPA benefits may be quickly depleted and that even closures of extended duration may be insufficient for long-term fisheries management if the MPAs are not maintained.