Overview Eight years of octopus fishery records from southwest Madagascar reveal significant positive impacts from 36 periodic closures on: (a) fishery catches and (b) village fishery income, such that (c) economic benefits from increased landings outweigh costs of foregone catch. Closures covered ~20% of a village’s fished area and lasted 2-7 months. Fishery Catches from Each Closed Site Octopus landings and catch per unit effort (CPUE) significantly increased in the 30 days following a closure’s reopening, relative to the 30 days before a closure (landings: +718%, p<0.0001; CPUE: +87%, p<0.0001; n = 36). Open-access control sites showed no before/after change when they occurred independently of other management (“no ban”, n = 17/36). On the other hand, open-access control sites showed modest catch increases when they extended a 6-week seasonal fishery shutdown (“ban”, n = 19/36). The seasonal fishery shutdown affects the entire region, so confound all potential control sites. Fishery Income in Implementing Villages In villages implementing a closure, octopus fishery income doubled in the 30 days after a closure, relative to 30 days before (+132%, p<0.001, n = 28). Control villages not implementing a closure showed no increase in income after “no ban” closures and modest increases after “ban” closures. Villages did not show a significant decline in income during closure events. Net Economic Benefits from Each Closed Site Landings in closure sites generated more revenue than simulated landings assuming continued open-access fishing at that site (27/36 show positive net earnings; mean +$305/closure; mean +57.7% monthly). Benefits accrued faster than local fishers’ time preferences during 17-27 of the 36 closures. High reported rates of illegal fishing during closures correlated with poor economic performance. Broader Co-Management We discuss the implications of our findings for broader co-management arrangements, particularly for catalyzing more comprehensive management.
Blue Ventures Conservation, 39–41 North Road, London, N7 9DP, United Kingdom;Department of Biology, University of Hawaiʻi Mānoa, 2853 McCarthy Mall, Edmondson Hall 309, Honolulu, Hawaii, 96822, United States of America;Blue Ventures Conservation, 39–41 North Road, London, N7 9DP, United Kingdom;Department of Natural Resources and Environmental Management, University of Hawaiʻi Mānoa, 1910 East West Road, Sherman 101, Honolulu, Hawaii, 96822, United States of America;Blue Ventures Conservation, 39–41 North Road, London, N7 9DP, United Kingdom;Blue Ventures Conservation, 39–41 North Road, London, N7 9DP, United Kingdom;Blue Ventures Conservation, 39–41 North Road, London, N7 9DP, United Kingdom;Blue Ventures Conservation, 39–41 North Road, London, N7 9DP, United Kingdom;Environmental Change Institute, University of Oxford, South Parks Road, Oxford, OX1 3QY, United Kingdom
Recommended Citation:
Thomas A. Oliver,Kirsten L. L. Oleson,Hajanaina Ratsimbazafy,et al. Positive Catch & Economic Benefits of Periodic Octopus Fishery Closures: Do Effective, Narrowly Targeted Actions ‘Catalyze’ Broader Management?[J]. PLOS ONE,2015-01-01,10(6)