Sea urchin-kelp forest communities in marine reserves and areas of exploitation : community interactions, populations, and metapopulation analyses

Marine ecosystems can be exposed to natural and anthropogenic disturbances that can lead to ecological failures. Marine reserves have been lately suggested to protect marine populations and communities that have been affected by habitat destruction and harvest. This research evaluates the potential role of two marine reserves established in Oregon in 1967 (Whale Cove) and 1993 (Gregory Point). The red sea urchin (Strongylocentrotus franciscanus) was selected as indicator of population recovery since it is the only species that is commercially harvested. Changes in density, biomass, average size, size structure, growth and mortality rates were evaluated through time to assess population recovery. These parameters were also compared between reserves and adjacent exploited areas to evaluate the effect of exploitation. Results from Whale Cove (old reserve) indicate that the population in this area is fully recovered. On the contrary, the population in Gregory Point (new reserve) showed signs of recovery after six years of being protected. The importance of red urchins as source populations to provide larvae to adjacent areas was explored by the analysis of drifter's trajectories. Both reserves might be connected in a network where larvae produced in Whale Cove will provide recruits to Gregory Point and adjacent exploited areas, as well as populations in northern California. Gregory Point releases larvae that become recruits for Whale Cove only when spawning takes place in winter, otherwise larvae travel to central California. No clear trends were found in growth and mortality rates between reserves and non-reserves; differences were more related with food availability, competitors, and age specific mortality. We applied qualitative simulations to characterize and differentiate the community network inside reserves and exploited areas. Results suggest that communities from a particular site can be represented by a set of alternative models with consistent species interactions. Differences in predator-prey interactions as well as non-predatory relationships (interference competition, mutualism, amensalism) were found among sites. Each set of models represents a hypothesis of community organization that agreed with natural history information. Alternative models suggest that kelp forest communities are dynamic and can shift from one network configuration to another providing a buffer against a variable environment

Variación espacio-temporal de la densidad poblacional de erizo rojo Strongylocentrotus franciscanus (Echinodermata: Echinoidea: Strongylocentrotidae) en Baja California

Density estimations of red sea urchin Strongylocentrotus franciscanus were recorded in ten sites with commercial fisheries on the west coast of Baja California, Mexico. The estimations for the years 2003, 2005, 2006 and 2008 were compared. The variations observed in the study sites indicate important spatial and temporal differences in density and size structure, influenced by fishing intensity and sporadic recruitment in each site. We found two sites (San Jeronimo Island and Sacramento Reef) with a high density and wide size structure; with a predominance of individuals of sizes from 50 to 80 mm with lest impact possible in fishing mortality for all sites.Se estimó la densidad poblacional de erizo rojo, Strongylocentrotus franciscanus, en 10 localidades de la costa occidental de Baja California, México, donde se realiza la extracción comercial de este recurso pesquero. Se compararon las estimaciones realizadas en cuatro años muestreados: 2003, 2005, 2006 y 2008. Las variaciones observadas en las localidades analizadas indicaron diferencias espacio-temporales para la densidad de erizo rojo y diferencias en la estructura de tallas, las cuales estuvieron influenciadas principalmente por la intensidad de la pesca y al esporádico reclutamiento en cada sitio. Se encontraron dos localidades (Isla San Jerónimo y Arrecife Sacramento) que destacaron por presentar una alta densidad de erizo rojo y una amplia estructura de tallas, predominando individuos de tallas entre 50 a 80 mm diámetro de caparazón, lo que podría indicar que la intensidad de pesca aparentemente tiene un menor efecto que en los otros sitios

The Role of Mpas in the Development of Northwest Mexico Fisheries

The northwest coast of Mexico is accountable for almost 70 % of the country´s fishery production. This region, which includes the Gulf of California and the Pacific coast of the Baja California Peninsula, is also extremely important in terms of biodiversity and the presence of endemic species. Consequently, eleven marine protected areas (MPAs) have been established along the region. Although conceived primarily for biodiversity conservation, natural protected areas are having increasingly important socioeconomic effects. To better understand the effects on coastal communities, we conducted an analysis of the role that MPAs are having in the development of the region´s fisheries. Six MPAs were selected for analysis using case study methodology. The main issue under investigation is the effect on fishery productivity. Main sources of information were documental research, official fishery statistics and expert consultation. Preliminary results suggest that the impact of MPAs on fishery productivity has been mixed. Better results have been achieved by the MPAs of the Pacific coast of Baja California; and that community involvement in MPA design and management has been instrumental in explaining these improvements

Um modelo qualitativo da comunidade biológica do Norte do Golfo da Califórnia, México: possíveis efeitos na exploração no ecossistema

El manejo basado en ecosistemas (MBE) es uno de los principales paradigmas bajo los cuales se están rediseñando las pesquerías mundiales. Sin embargo, la implementación exitosa del MBE se ha visto limitada debido a la complejidad intrínseca de los sistemas ecológicos y a la necesidad de tener suficiente información para construir y analizar modelos complejos. Para implementar exitosamente un MBE en pesquerías, países como México necesitan diseñar y promover herramientas de manejo acordes a su contexto social y natural, y así aprovechar de las capacidades de su sistema pesquero. En este trabajo se utilizó un modelo cualitativo (Loop Analysis) para visualizar las implicaciones ecosistémicas de la explotación pesquera sobre algunos de los miembros de una comunidad marina. Con base en seis grupos de interés pesquero y un grupo de interés para la conservación, construimos un modelo sobre la comunidad biológica sujeta a pesca del Norte del Golfo de California (NGC).  El análisis de las predicciones del modelo permitió conocer los efectos directos e indirectos de la explotación de diferentes grupos pesqueros, así como identificar las pesquerías que pueden presentar conflicto al operar de manera simultánea. La naturaleza cualitativa del modelo permitió incorporar como fuente de información el conocimiento ecológico local (CEL), propiciando así el futuro involucramiento de los actores en el diseño de estrategias de manejo. Las ideas generadas pueden ser útiles para establecer objetivos tanto de utilización de los recursos como de conservación, y proporcionan una guía para elaborar propuestas de manejo basadas en el conocimiento del ecosistema.Ecosystem-based management (EBM) is one of the main paradigms under which the world’s fisheries have been redesigned. However, successful implementation of EBM has been limited due to the inherent complexity of ecological systems as well as the need to have enough information to build and analyze complex models. To successfully implement EBM in fisheries, countries such as Mexico need to design and promote management tools consistent with their social and natural context in a way that they can take advantage of the capabilities of their fishery systems. In this paper we used a qualitative model (Loop Analysis) to examine the ecosystem implications of fishery on some members of a marine community.  A model for the biological community of the Northern Gulf of California (NGC) was constructed, based on six fishery groups and a conservation group. Model predictions allowed assessing both direct and indirect effects from harvesting different fishery groups, as well as identifying those fisheries that might present a conflict when operating simultaneously. The qualitative nature of the model allowed incorporating local ecological knowledge (LEK) as a source of information, fostering the future involvement of stakeholders in the design of management strategies. The proposed ideas may be useful to generate goals regarding resource exploitation and conservation and also provide a guide to generate management strategies based on the knowledge of the ecosystem.O manejo baseado em ecossistemas (MBE) é um dos principais paradigmas sob os quais as pesqueiras mundiais estão se redesenhando. Entretanto, em uma implementação exitosa do MBE vê-se limitada devido à complexidade intrínseca dos sistemas ecológicos e à necessidade de ter suficiente informação para construir e analisar modelos complexos. Para implementar com sucesso um MBE em pesqueiras, países como o México necessitam desenhar e promover ferramentas de manejo conforme o contexto social e natural, e assim tirar vantagem das capacidades de seu sistema pesqueiro. Neste trabalho se utilizou um modelo qualitativo (Loop Analysis) para visualizar as implicações ecossistêmicas da exploração pesqueira sobre alguns dos membros de uma comunidade marinha. Baseados em seis grupos de interesse pesqueiro e um grupo de interesse pela conservação construímos um modelo sobre a comunidade biológica sujeita a pesca do Norte do Golfo da Califórnia (NGC).  A análise das previsões do modelo permitiu conhecer os efeitos diretos e indiretos da exploração de diferentes grupos pesqueiros, assim como identificar as pesqueiras que podem apresentar conflito ao operar de maneira simultânea. A natureza qualitativa do modelo permitiu incorporar como fonte de informação o conhecimento ecológico local (CEL), propiciando dessa maneira, o futuro envolvimento dos atores no desenho de estratégias de manejo. As ideias geradas podem ser úteis para estabelecer objetivos, tanto de utilização dos recursos como de conservação, e proporcionam um guia para elaborar propostas de manejo baseadas no conhecimento do ecossistema.

Using Traditional Ecological Knowledge to Improve Holistic Fisheries Management: Transdisciplinary Modeling of a Lagoon Ecosystem of Southern Mexico

We developed a transdisciplinary modeling approach for the Huave Lagoon System (HLS), Mexico. This lagoon was selected because it has been used sustainably in various complimentary ways by different ethnic groups since pre-Hispanic times. Over the last few years, however, the ecological impact of artisanal fisheries in the region has grown significantly, thus endangering the balance between society and nature. Because the Huaves and the Zapotecs are ancestral fishing cultures with a profound knowledge of ecosystem resources and local property rights, the aim of this study was to identify ecosystem-level management alternatives capable of diminishing fishing impacts to the HLS. We used a consensus-building process and applied the user's traditional ecological knowledge (TEK). Our counterintuitive results show that specific management strategies should be considered for each particular fishing seascape within the HLS while taking into account the differences among ecological structures and fishery dynamics. The insights from this research aid in defining holistic management policies and support spatial allocations of use rights in local fisheries

Un modelo cualitativo de la comunidad biológica del Norte del Golfo de California, México: posibles efectos de la explotación pesquera en el ecosistema

Ecosystem-based management (EBM) is one of the main paradigms under which the world’s fisheries have been redesigned. However, successful implementation of EBM has been limited due to the inherent complexity of ecological systems as well as the need to have enough information to build and analyze complex models. To successfully implement EBM in fisheries, countries such as Mexico need to design and promote management tools consistent with their social and natural context in a way that they can take advantage of the capabilities of their fishery systems. In this paper we used a qualitative model (Loop Analysis) to examine the ecosystem implications of fishery on some members of a marine community.  A model for the biological community of the Northern Gulf of California (NGC) was constructed, based on six fishery groups and a conservation group. Model predictions allowed assessing both direct and indirect effects from harvesting different fishery groups, as well as identifying those fisheries that might present a conflict when operating simultaneously. The qualitative nature of the model allowed incorporating local ecological knowledge (LEK) as a source of information, fostering the future involvement of stakeholders in the design of management strategies. The proposed ideas may be useful to generate goals regarding resource exploitation and conservation and also provide a guide to generate management strategies based on the knowledge of the ecosystem.El manejo basado en ecosistemas (MBE) es uno de los principales paradigmas bajo los cuales se están rediseñando las pesquerías mundiales. Sin embargo, la implementación exitosa del MBE se ha visto limitada debido a la complejidad intrínseca de los sistemas ecológicos y a la necesidad de tener suficiente información para construir y analizar modelos complejos. Para implementar exitosamente un MBE en pesquerías, países como México necesitan diseñar y promover herramientas de manejo acordes a su contexto social y natural, y así aprovechar de las capacidades de su sistema pesquero. En este trabajo se utilizó un modelo cualitativo (Loop Analysis) para visualizar las implicaciones ecosistémicas de la explotación pesquera sobre algunos de los miembros de una comunidad marina. Con base en seis grupos de interés pesquero y un grupo de interés para la conservación, construimos un modelo sobre la comunidad biológica sujeta a pesca del Norte del Golfo de California (NGC).  El análisis de las predicciones del modelo permitió conocer los efectos directos e indirectos de la explotación de diferentes grupos pesqueros, así como identificar las pesquerías que pueden presentar conflicto al operar de manera simultánea. La naturaleza cualitativa del modelo permitió incorporar como fuente de información el conocimiento ecológico local (CEL), propiciando así el futuro involucramiento de los actores en el diseño de estrategias de manejo. Las ideas generadas pueden ser útiles para establecer objetivos tanto de utilización de los recursos como de conservación, y proporcionan una guía para elaborar propuestas de manejo basadas en el conocimiento del ecosistema

Benthic community structure in kelp forests from the Southern California Bight

The United States and Mexico share the Southern California Bight (SCB) ecosystem in the Northeast Pacific Ocean where marine wildlife and habitats historically have been disturbed by human activities. Within this ecosystem, forests of the giant kelp Macrocystis pyrifera are critical habitats that sustain diverse biological assemblages and important fishery species. We studied patterns of temporal and spatial variability within the benthic communities of five transboundary kelp forests in California (USA) and Baja California (Mexico) over a fouryear period that included a moderate El Niño event. While the benthic marine communities shared some species, they varied significantly in community structure from each other, and the degree of dissimilarity was not related to the geographic distances among the studied habitats. Rather, species richness was significantly related to local substratum rugosity, suggesting it could be used as a proxy of relative benthic biological diversity. Temporal changes in the benthic assemblages were not consistent across all forests, and contrary to observations made during previous El Niño events in the SCB, the benthic communities did not change significantly following the 2009–2010 El Niño. Such an unexpected community response may be explained by the fact that the 2009–2010 El Niño was linked to the Modoki phenomenon, where warm sea surface temperature is focused in the central equatorial Pacific and not in the eastern Pacific Ocean. We propose that long-term conservation efforts should incorporate this ecological knowledge to support science-based decisions, binational coordination of policies, and coherent management practices including the design of transboundary conservation networks as spatial management tools for the protection, conservation, and/or restoration of the SCB ecosystem.

Análisis de actores de la pesquería de medusa en Guaymas, Sonora

El objetivo de esta investigación fue conocer el rol de los actores involucrados en la pesquería de medusa bola de cañón, en Guaymas, Sonora. Con el método bola de nieve se realizaron entrevistas semiestructuradas, luego se jerarquizaron mediante la red de poder/interés de cuatro cuadrantes, y se relacionaron con una matriz de vinculación. El resultado arrojó que el Instituto Nacional de Pesca, los compradores, procesadores, comercializadores y las cooperativas pesqueras son los actores clave, con mayor interés e influencia en el manejo de la pesquería. El presente análisis es útil para establecer y mejorar el manejo de la captura de medusa. Se concluye que existe una relación conflictiva y de poca cooperación entre los actores mencionados, lo cual impide que se respeten las estrategias de manejo para explotar la medusa en condiciones de sustentabilidad