Lessons learnt from experimental temporary octopus fishing closures in south-west Madagascar: benefits of concurrent closures

Abstract

This paper presents evidence of the fisheries effect of experimental temporary fishing closures for Octopus cyanea in the then-emergent Velondriake Locally Managed Marine Area (LMMA) in south-west Madagascar during 2004–2006. We present an analysis of the O. cyanea catch data for the first two years of temporary closures based on landings data collected from village-based octopus collectors. We found a significant closure effect in terms of total weight and number of octopus caught on opening days, but observed that these benefits dissipated quickly, returning to pre-closure levels within days. Mean octopus size increased by 41% on average when compared to data from selected control sites. However, extremely high levels of fishing effort on opening days meant that these biological effects did not translate into increased weight of octopus caught per successful fisher over the opening tide. Upon opening of concurrent closures during the second round of closures we found significant increases in the weight of octopus caught per successful fisher. We conclude that the pilot closures had a significant closure effect, but caution against isolated openings leading to concentrated fishing effort on opening days.