72 research outputs found

    Perspectives for implementing fisheries certification in developing countries

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    This paper discusses the future of the Marine Stewardship Council (MSC), a market-based certification program, in developing countries and exposes the challenges and opportunities for fish producers. The MSC needs to attract the interest of more fishing enterprises from these regions to increase its global presence. Because most fisheries in developing countries cannot meet the MSC standards, or afford the certification process costs, it is suggested that there is a need for developing different levels within the MSC system and additional third-party assessing organizations. MSC certification may mean adoption of improvements in fisheries management and approving fishing regimes in developing countries. However, post-certification benefits may decrease as more fisheries become certified

    Oxygen: A Fundamental Property Regulating Pelagic Ecosystem Structure in the Coastal Southeastern Tropical Pacific

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    Background: In the southeastern tropical Pacific anchovy (Engraulis ringens) and sardine (Sardinops sagax) abundance have recently fluctuated on multidecadal scales and food and temperature have been proposed as the key parameters explaining these changes. However, ecological and paleoecological studies, and the fact that anchovies and sardines are favored differently in other regions, raise questions about the role of temperature. Here we investigate the role of oxygen in structuring fish populations in the Peruvian upwelling ecosystem that has evolved over anoxic conditions and is one of the world's most productive ecosystems in terms of forage fish. This study is particularly relevant given that the distribution of oxygen in the ocean is changing with uncertain consequences. Methodology/Principal Findings: A comprehensive data set is used to show how oxygen concentration and oxycline depth affect the abundance and distribution of pelagic fish. We show that the effects of oxygen on anchovy and sardine are opposite. Anchovy flourishes under relatively low oxygen conditions while sardine avoid periods/areas with low oxygen concentration and restricted habitat. Oxygen consumption, trophic structure and habitat compression play a fundamental role in fish dynamics in this important ecosystem. Conclusions/Significance: For the ocean off Peru we suggest that a key process, the need to breathe, has been neglected previously. Inclusion of this missing piece allows the development of a comprehensive conceptual model of pelagic fish populations and change in an ocean ecosystem impacted by low oxygen. Should current trends in oxygen in the ocean continue similar effects may be evident in other coastal upwelling ecosystems

    Challenges for Implementing an Ecosystem Approach to Fisheries Management

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    The ecosystem approach is being promoted as the foundation of solutions to the unsustainability of fisheries. However, because the ecosystem approach is broadly inclusive, the science for its implementation is often considered to be overly complex and difficult. When the science needed for an ecosystem approach to fisheries is perceived this way, science products cannot keep pace with fisheries critics, thus encouraging partisan political interference in fisheries management and proliferation of “faith-based solutions. In this paper we argue that one way to effectively counter politicization of fisheries decision-making is to ensure that new ecosystem-based approaches in fisheries are viewed only as an emergent property of innovation in science and policy. We organize our essay using three major themes to focus the discussion: empirical, jurisdictional, and societal challenges. We undertake at least partial answers to the following questions: (1) has conventional fisheries management really failed?; (2) can short-comings in conventional fisheries management be augmented with new tools, such as allocation of rights?; (3) is the Ecosystem Approach to Fisheries (EAF) equivalent to Ecosystem-Based Management?; and (4) is restoration of degraded ecosystems a necessary component of an EAF

    Ecological commonalities among pelagic fishes: comparison of freshwater ciscoes and marine herring and sprat

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    Systematic comparisons of the ecology between functionally similar fish species from freshwater and marine aquatic systems are surprisingly rare. Here, we discuss commonalities and differences in evolutionary history, population genetics, reproduction and life history, ecological interactions, behavioural ecology and physiological ecology of temperate and Arctic freshwater coregonids (vendace and ciscoes, Coregonus spp.) and marine clupeids (herring, Clupea harengus, and sprat, Sprattus sprattus). We further elucidate potential effects of climate warming on these groups of fish based on the ecological features of coregonids and clupeids documented in the previous parts of the review. These freshwater and marine fishes share a surprisingly high number of similarities. Both groups are relatively short-lived, pelagic planktivorous fishes. The genetic differentiation of local populations is weak and seems to be in part correlated to an astonishing variability of spawning times. The discrete thermal window of each species influences habitat use, diel vertical migrations and supposedly also life history variations. Complex life cycles and preference for cool or cold water make all species vulnerable to the effects of global warming. It is suggested that future research on the functional interdependence between spawning time, life history characteristics, thermal windows and genetic differentiation may profit from a systematic comparison of the patterns found in either coregonids or clupeids

    Caso de estudio sobre el uso de bases de datos ambientales de baja resolución espacial, como una alternativa para inferir hábitat de desove.

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    En este trabajo se prueba la factibilidad de utilizar datos ambientales de baja resolución y fácil obtención para inferir hábitat de desove de la sardina monterrey del Golfo de California, en el dominio de la temperatura. Se compararon resultados publicados, basados en mediciones de temperatura asociadas al muestreo biológico, con cálculos a partir de datos extraídos de una base pública. Los resultados muestran que existen similitudes importantes entre ambas estimaciones, a pesar de las grandes diferencias entre las dos fuentes de datos. Este resultado es relevante para algunas iniciativas en curso, donde se pretende incorporar información ambiental, de fácil acceso y oportuna, a sistemas de información para la pesquería de sardina del Golfo de California

    Análisis de la flota sardinera-anchovetera del noroeste de México

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    Se hace un análisis de la flota sardinera-anchovetera del Noroeste de México, con especial énfasis en su eficiencia operativa de pesca. Dicho análisis comprende aspectos relacionados con las características de las embarcaciones; así mismo, se determina la eficiencia operativa de la flota por dos vías; una estimando los poderes relativos de pesca con ayuda del la CPUE y por el otro lado se evalúa la capacidad de bodega utilizada por los barcos en términos de porcentaje. Se hace también una proyección del potencial de pesca por parte de la flota y se relaciona la movilidad de dicha flota con su eficiencia. El estudio concluye que la dimensión de la flota actual no debe incrementarse, que barcos "chicos" y "grandes" operan diferencialmente de acuerdo al recurso sobre el cual estén actuando (sardina o anchoveta), que la categoría de barcos más eficientes operativamente hablando son los de 101 - 150 toneladas de capacidad de bodega y que es necesario un adecuado manejo de la flota en su conjunto (movilidad de la flota) para incrementar los volúmenes de captura sin necesidad de que la flota sufra un incremento en su número, procurando con ello evitar sobre capitalización en la fase extractiva en particular y de la pesquería en lo general

    Multiscale characterization of the sea temperature in an area of abalone banks (Haliotis spp.) at Bahia Asuncion, Baja California Sur, Mexico

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    The Baja California abalone is one of the most important Mexican fisheries because of its high economic value. Despite strong management efforts, this fishery has faced dramatic fluctuations attributed mainly to overfishing and variability of the marine climate. In this report we analyze sea temperature variability off Bahía Asunción, Baja California Sur (Mexico), at temporal scales that may affect abalone biological processes, such as mortality, reproduction, recruitment, and individual growth rate. Since the analysis is based on different data sources, we conducted a series of correlation analyses to determine the coherence between them. We report the average daily cycle and its variations throughout the year and between years for the period 1997–2000, the seasonal cycle and interannual deviations for the period 1992–2000, the behavior of the decadal scale variability based on annual values for the period 1959–1997, and the long-term trends after analyzing the entire 20th century. Furthermore, we conducted a spectral density analysis to estimate the proportional contribution of each temporal scale to the entire variability signal. Results from the high-frequency variability (daily to interannual) suggest a relationship between temperature and the abalone reproductive cycles, a potential negative effect of the very strong ENSO events on the postlarvae, and a differential effect of temperature on juveniles of different species. Regarding the low-frequency variability (decadal to century), we show that recent years represent a much warmer period compared to previous decades, suggesting a different biological community structure between periods. The spectral density analysis indicates seasonal variability as the major contributor to the regional variability, followed by the interannual (related to ENSO). There is almost no information of the marine climate in this region, particularly in regard to fine and high-resolution observations. This contribution will provide new quantitative elements for studies dealing with the ecology of these coastal productive systems

    Recent trends in sea surface temperature off Mexico

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    Changes in global mean sea surface temperature may have potential negative implications for natural and socioeconomic systems; however, measurements to predict trends in different regions have been limited and sometimes contradictory. In this study, an assessment of sea surface temperature change signals in the seas off Mexico is presented and compared to other regions and the world ocean, and to selected basin scale climatic indices of the North Pacific, the Atlantic and the tropical Pacific variability. We identified eight regions with different exposure to climate variability: In the Pacific, the west coast of the Baja California peninsula with mostly no trend, the Gulf of California with a modest cooling trend during the last 20 to 25 years, the oceanic area with the most intense recent cooling trend, the southern part showing an intense warming trend, and a band of no trend setting the boundary between North-Pacific and tropical-Pacific variability patterns; in the Atlantic, the northeast Gulf of Mexico shows cooling, while the western Gulf of Mexico and the Caribbean have been warming for more than three decades. Potential interactions with fisheries and coastal sensitive ecosystems are discusse
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