Overfishing drivers and opportunities for recovery in small-scale fisheries of the Midriff islands region, Gulf of California, Mexico: The role of land and sea institutions in fisheries sustainability

Institutions play an important role in shaping individual incentives in complex social-ecological systems, by encouraging or discouraging resource overuse. In the Gulf of California, Mexico, there is widespread evidence of declines in small-scale fishery stocks, largely attributed to policy failures. We investigated formal and informal rules-in-use regulating access and resource use by small-scale fishers in the two most important fishing communities of the Midriff Islands region in the Gulf of California, which share several target species and fishing grounds. The Midriff Islands region is a highly productive area where sustainable use of fisheries resources has been elusive. Our study aimed to inform policy by providing information on how management and conservation policies perform in this unique environment. In addition, we contrast attributes of the enabling conditions for sustainability on the commons in an effort to better understand why these communities, albeit showing several contrasting attributes of the above conditions, have not developed sustainable fishing practices. We take a novel, comprehensive institutional approach that includes formal and informal institutions, incorporating links between land (i.e., communal land rights) and sea institutions (i.e., fisheries and conservation policies) and their effects on stewardship of fishery resources, a theme that is practically unaddressed in the literature. Insufficient government support in provision of secure rights, enforcement and sanctioning, and recognition and incorporation of local arrangements and capacities for management arose as important needs to address in both cases. We highlight the critical role of higher levels of governance, that when disconnected from local practices, realities, and needs, can be a major impediment to achieving sustainability in small-scale fisheries, even in cases where several facilitating conditions are met.Resumen: Las instituciones desempeñan un papel importante en la determinación de los incentivos individuales en sistemas socio-ecológicos complejos, alentando o desalentando la sobreexplotación. En el Golfo de California, México, existe amplia evidencia de una marcada disminución en la abundancia de recursos pesqueros de pequeña escala o artesanales, atribuida a fracasos en las políticas de manejo. Este trabajo investiga las reglas formales e informales en uso para regular acceso y uso de recursos por parte de pescadores artesanales en las dos comunidades pesqueras más importantes de la Región de las Grandes Islas, Golfo de California. A pesar de su elevada productividad biológica, el uso sustentable de los recursos marinos en esta región ha sido difícil de alcanzar. Este trabajo proporcionamo información para optimizar el desempeño de los instrumentos de manejo y conservación de recursos marinos presentes en este ambiente único. Además, contrastamos los atributos de las condiciones que facilitan la sustentabilidad en el uso de recursos de uso común, para comprender mejor por qué estas comunidades no han logrado incorporar de manera duradera prácticas de pesca sustentables, a pesar de presentar, en el caso particular de una de ellas, varias condiciones propicias. Adoptamos un enfoque institucional novedoso e integral que incluye instituciones formales e informales, e incorpora los vínculos entre reglas relativas a la tenencia de la tierra (ej. derechos de uso comunales) y del ámbito marino (de pesca y conservación), y sus efectos sobre el cuidado de los recursos marinos, un tópico prácticamente sin abordar en la literatura. Surgen como limitantes importantes en ambos casos, un apoyo gubernamental insuficiente tanto en la provisión de derechos de pesca seguros como en la fiscalización y la aplicación de sanciones, y la falta de reconocimiento e incorporación de arreglos institucionales y capacidades de manejo locales en instancias formales de decisión. Resaltamos el papel fundamental que cumplen los niveles de gobernanza más elevados, los que al estar desvinculados de las prácticas, realidades y necesidades locales, pueden obstaculizar de manera significativa el alcance de la sustentabilidad en pesquerías artesanales, incluso cuando varias condiciones favorables están presentes.Fil: Cinti, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. University Of Arizona; Estados UnidosFil: Duberstein, Jennifer N.. University Of Arizona; Estados UnidosFil: Torreblanca, Esteban. Pronatura Noroeste, A.C.; ArgentinaFil: Moreno Báez, Marcia. University Of Arizona; Estados Unido

Dynamic connectivity patterns from an insular marine protected area in the Gulf of California

We studied connectivity patterns from a small and isolated island in the Gulf of California (San Pedro Mártir Island Biosphere Reserve), as a source of propagules to surrounding Marine Protected Areas and fishing sites. We used a particle-tracking scheme based on the outputs of a three-dimensional numerical hydrodynamic model to assess the spatial domain to which the island exports larvae as well as larvae retention. We modeled the release of passive particles from locations around the island during the four release dates (May 15 and 31, and June 14 and 30), matching the lunar phases and the peak of the reproductive season for several commercial invertebrates and fish, at the time when currents in the Gulf typically reverse. For each simulation we analyzed the data at 15, 20 and 30 days after the release to represent different planktonic propagule durations. Particle dispersion was highly dynamic and spread over ~ 600 km along the coast over the study period. Overall, we observed potential ecological connectivity with a few key distant fishing sites that changed trough time, and potential genetic connectivity towards many near and distant sites, including all neighboring Marine Protected Areas, although not simultaneously. The percentages of particles remaining within the boundaries of the island tended to decline from May to June, and decreased with delayed planktonic propagule duration. The design of effective Marine Protected Areas should acknowledge the dynamic nature of connectivity patterns, for instance, by establishing adaptive network reserves to respond to changing ocean features that match reproductive patterns of target species and fisheries behavior.We studied connectivity patterns from a small and isolated island in the Gulf of California (San Pedro Mártir Island Biosphere Reserve), as a source of propagules to surrounding Marine Protected Areas and fishing sites. We used a particle-tracking scheme based on the outputs of a three-dimensional numerical hydrodynamic model to assess the spatial domain to which the island exports larvae as well as larvae retention. We modeled the release of passive particles from locations around the island during the four release dates (May 15 and 31, and June 14 and 30), matching the lunar phases and the peak of the reproductive season for several commercial invertebrates and fish, at the time when currents in the Gulf typically reverse. For each simulation we analyzed the data at 15, 20 and 30 days after the release to represent different planktonic propagule durations. Particle dispersion was highly dynamic and spread over ~ 600 km along the coast over the study period. Overall, we observed potential ecological connectivity with a few key distant fishing sites that changed trough time, and potential genetic connectivity towards many near and distant sites, including all neighboring Marine Protected Areas, although not simultaneously. The percentages of particles remaining within the boundaries of the island tended to decline from May to June, and decreased with delayed planktonic propagule duration. The design of effective Marine Protected Areas should acknowledge the dynamic nature of connectivity patterns, for instance, by establishing adaptive network reserves to respond to changing ocean features that match reproductive patterns of target species and fisheries behavior.Fil: Soria, Rodrigo Gaspar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Soria, Rodrigo Gaspar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Torre Cosio, Jorge. Comunidad y Biodiversidad A. C.; MéxicoFil: Torre Cosio, Jorge. Comunidad y Biodiversidad A. C.; MéxicoFil: Munguia Vega, Adrián. Comunidad y Biodiversidad A. C.; México. University of Arizona; Estados UnidosFil: Munguia Vega, Adrián. Comunidad y Biodiversidad A. C.; México. University of Arizona; Estados UnidosFil: Marinone, Silvio Guido. Centro de Investigación Científica y de Educación Superior de Ensenada; MéxicoFil: Marinone, Silvio Guido. Centro de Investigación Científica y de Educación Superior de Ensenada; MéxicoFil: Lavín, Miguel F.. Centro de Investigación Científica y de Educación Superior de Ensenada; MéxicoFil: Lavín, Miguel F.. Centro de Investigación Científica y de Educación Superior de Ensenada; MéxicoFil: Cinti, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Cinti, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Moreno Báez, Marcia. University of California at San Diego; Estados UnidosFil: Moreno Báez, Marcia. University of California at San Diego; Estados Unido

Correction: A spatial method to calculate small-scale fisheries effort in data poor scenarios.

[This corrects the article DOI: 10.1371/journal.pone.0174064.]

Dynamic connectivity patterns from an insular marine protected area in the Gulf of California

AbstractWe studied connectivity patterns from a small and isolated island in the Gulf of California (San Pedro Mártir Island Biosphere Reserve), as a source of propagules to surrounding Marine Protected Areas and fishing sites. We used a particle-tracking scheme based on the outputs of a three-dimensional numerical hydrodynamic model to assess the spatial domain to which the island exports larvae as well as larvae retention. We modeled the release of passive particles from locations around the island during the four release dates (May 15 and 31, and June 14 and 30), matching the lunar phases and the peak of the reproductive season for several commercial invertebrates and fish, at the time when currents in the Gulf typically reverse. For each simulation we analyzed the data at 15, 20 and 30days after the release to represent different planktonic propagule durations. Particle dispersion was highly dynamic and spread over ~600km along the coast over the study period. Overall, we observed potential ecological connectivity with a few key distant fishing sites that changed trough time, and potential genetic connectivity towards many near and distant sites, including all neighboring Marine Protected Areas, although not simultaneously. The percentages of particles remaining within the boundaries of the island tended to decline from May to June, and decreased with delayed planktonic propagule duration. The design of effective Marine Protected Areas should acknowledge the dynamic nature of connectivity patterns, for instance, by establishing adaptive network reserves to respond to changing ocean features that match reproductive patterns of target species and fisheries behavior

A spatial method to calculate small-scale fisheries effort in data poor scenarios

<div><p>To gauge the collateral impacts of fishing we must know where fishing boats operate and how much they fish. Although small-scale fisheries land approximately the same amount of fish for human consumption as industrial fleets globally, methods of estimating their fishing effort are comparatively poor. We present an accessible, spatial method of calculating the effort of small-scale fisheries based on two simple measures that are available, or at least easily estimated, in even the most data-poor fisheries: the number of boats and the local coastal human population. We illustrate the method using a small-scale fisheries case study from the Gulf of California, Mexico, and show that our measure of Predicted Fishing Effort (PFE), measured as the number of boats operating in a given area per day adjusted by the number of people in local coastal populations, can accurately predict fisheries landings in the Gulf. Comparing our values of PFE to commercial fishery landings throughout the Gulf also indicates that the current number of small-scale fishing boats in the Gulf is approximately double what is required to land theoretical maximum fish biomass. Our method is fishery-type independent and can be used to quantitatively evaluate the efficacy of growth in small-scale fisheries. This new method provides an important first step towards estimating the fishing effort of small-scale fleets globally.</p></div