From boom to decline: Spatio-temporal evolution and management of New Caledonia's sea cucumber fisheries

Sea cucumber fisheries worldwide have evolved considerably in response to market demands and effects of exploitation. Reports of overfishing abound yet studies have rarely examined the processes within the fishery systems and the efficacy of various management measures. New Caledonia is one of few Pacific Island territories/countries to have continued producing wild sea cucumbers without moratoria. We examined the changes in fishery production, fleet capacity and target species between the Northern and Southern Provinces’ sea cucumber fisheries over the past decades and the applied management measures. Capture production declined more than 70 % since the 1980s. Fishers sometimes harvested other resources on fishing trips, but often focussed on sea cucumbers, entailing 20 species. Landings and catch composition differed vastly between the two provinces and medium-value species were significantly targeted in recent years. Fleet capacity quadrupled over a few years, increasing pressure on the resource already declining in production. Underreporting by fishers of teatfish (Microthele) species following their listing on CITES Appendix II highlights difficulties in using quotas as a management tool. Minimum legal-size limits and a ban on compressed-air diving did not prevent decline but might have mitigated collapse of the fishery. Our study finds hyperstability through shifts in target species over time and resilience of some species to fishing pressure. We reveal that management imperatives might differ between fisheries within a country, requiring region-specific solutions. Constraining fleet capacity and numbers of fishers are ongoing challenges for sustaining small-scale, artisanal sea cucumber fisheries.