Positive Catch and Economic Benefits of Periodic Octopus Fishery Closures: Do Effective, Narrowly Targeted Actions 'Catalyze' Broader Management?

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.We discuss the implications of our findings for broader co-management arrangements, particularly for catalyzing more comprehensive management

Fishing site mapping using local knowledge provides accurate and satisfactory results: Case study of Octopus fisheries in Madagascar

Accurate fishing ground maps are necessary for fisheries monitoring. In Velondriake locally managed marine area (LMMA) we observed that the nomenclature of shared fishing sites (FS) is villages dependent. Additionally, the level of illiteracy makes data collection more complicated, leading to data collectors improvising when recording FS. In this case study for Velondriake we opted for a participatory approach giving special consideration to local knowledge in mapping octopus fishing grounds. Other techniques (single or multiple GPS points) have been tried but gave overlapping maps for neighboring FS, and do not reflect reality. Local fishers know the exact extent of their fishing grounds and are able to draw them accurately. We utilized a printed habitat map or Google Earth satellite imagery, and asked fishers to draw in each FS. Using this technique, 325 sites were identified from 13 villages, without any overlaps or duplications, making a valuable contribution to fisheries management efforts. This supports the contention that local knowledge, and the participation of local fishers, is crucial in conservation. This approach strengthens the relationship between scientists, managers and local communities. This technique is cost effective and adaptable to each situation, and is now widely used by Malagasy fishing communities.

Mean Village Level Octopus Income Before and After Temporary Closures.

<p>Mean Village Level Octopus Income Before and After Temporary Closures.</p

Closure effects on Village Fishery Income.

<p>Total village-level octopus fishing income ($PPP) 30 days before, during, and after closures, at villages both with and without closures. The data depicted are from 28 closure periods showing closure-implementing villages and their control villages from 2004–2011. Data are separated by season, thus separating closures that occurred independently of a regional fishery shutdown (“no ban”), and those that extended the shutdown (“ban”). As “during” periods are not exactly 30 days, “during” values are scaled to a per-30-day measure. Significance indicators show distinctions between a particular group and its “before” group comparison, from linear mixed-effect model. NS = Not Significant; * = p < 0.05; ** = p < 0.01; *** = p < 0.001. For effort, value per unit effort, and data aggregated across seasons, please see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129075#pone.0129075.s005" target="_blank">S5</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129075#pone.0129075.s006" target="_blank">S6</a> Figs.</p

Closure Site Net Economic Benefits.

<p>Closure Site Net Economic Benefits.</p

Maps of Study Area.

<p>(A) Large-scale map of Madagascar and the African continent, (B) Inset of the 25 villages of the Velondriake Locally Managed Marine Area in southwestern Madagascar. Vertical box extent is ~75 km. (C) Representative example of a periodic octopus fishery closure. Indicated in the map are two villages, Andavadoaka and Ampasilava, with their respective octopus fishing sites mapped in orange and yellow. In green, you can see the sites Amagnahitse and Nosinkara, in which these two villages have repeatedly co-implemented a periodic octopus fishery closure.</p