Resumen de Implementing ecosystem approach to fisheries management: Advances and new tools

María G. Pennino

• español

  Desde la antigüedad, la pesca ha sido una fuente importante de alimentos para la humanidad, así como fuente de empleo y beneficios económicos para quienes se dedican a esta actividad. Sin embargo, con el aumento de los conocimientos científicos y la evolución dinámica de la pesca se hizo evidente de que los recursos acuáticos, aunque renovables, no eran infinitos y era necesario gestionar adecuadamente su contribución al bienestar nutricional, económico y el bienestar social de la población mundial para un crecimiento y desarrollo sostenible. En los últimos años, la pesca mundial se ha convertido en un sector dinámico y de desarrollo de la industria alimentaria. Los estados costeros han procurado aprovechar sus nuevas oportunidades invirtiendo en flotas pesqueras modernas y fábricas de procesamiento en respuesta a la creciente demanda internacional de pescado y productos pesqueros. Sin embargo, se ha constatado que la explotación pesquera no puede mantener un aumento incontrolado sin provocar un perjuicio a la salud de los recursos pesqueros. En diversos foros se expresa gran preocupación acerca de la contribución de la pesca al desarrollo sostenible, la sobrepesca, el exceso de capacidad de las flotas, el agotamiento de algunas poblaciones, los cambios inducidos por el hombre en los ecosistemas, así como el aumento y la globalización del comercio pesquero con su potencial impacto en el abastecimiento local. Para hacer frente a estos problemas, las Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO) ha pedido la aplicación de un enfoque ecosistémico a la gestión de la pesca (EAFM), cuyo objetivo es lograr una explotación sostenible de la pesca comercial, que tenga en cuenta las interacciones entre las artes de pesca y los ecosistemas marinos. Un EAFM tiene en cuenta que la pesca es una componente del ecosistema y no se puede gestionar de forma aislada. Un EAFM debe considerar la aplicación de los principios del desarrollo sostenible en el sector pesquero, la combinación de la sostenibilidad ecológica, la viabilidad económica y la equidad social. No obstante, aunque se reconoce que la pesca es importante para el desarrollo sostenible y que su contribución puede ser mejorada, la cantidad de información científica objetiva sobre la pesca es limitada y a menudo la información que existe es de difícil acceso. La fiabilidad del asesoramiento científico para la gestión de los recursos naturales depende en gran medida de la cantidad y calidad de los datos disponibles para la evaluación científica y su interpretación. Es cierto que hay una enorme cantidad de datos sobre los ecosistemas marinos y que además son fácilmente accesibles a través de plataformas online (como por ejemplo los datos de teleobservación obtenidos por satélite y observaciones basadas en telemetría automática). Sin embargo, la gran mayoría de los casos tenemos que lidiar con datos limitados e irregularmente espaciados (por ejemplo, de peces y otra fauna marina). Además, los datos no siempre son directamente comparables debido a las variaciones en las condiciones ambientales entre períodos de muestreo. La razón principal es que en investigación pesquera la recogida de datos es comúnmente costosa tanto en tiempo como en dinero. Además, los problemas aumentan cuando el objetivo de la investigación consiste en examinar los cambios en la dinámica de todo un ecosistema mediante el estudio de largas series temporales en una escala macro-espacial. En estos casos, para los que se requiere grandes bases de datos con una cobertura adecuada en el espacio y tiempo de una variedad de variables, la información es casi inexistente. Por otra parte, la información sobre el estado de la pesca se puede derivar de muestreos diferentes tales como los muestreos independientes de las pesquerías y los muestreos dependientes de la pesca, así como los datos de desembarcos de la FAO. Cada una de estas fuentes ofrece diferentes tipos de información, que debe ser cuidadosamente seleccionada en función del tipo de estudio y los objetivos perseguidos. Los muestreos de datos independientes de la pesquería se basan principalmente en campañas de investigación realizadas durante períodos de tiempo relativamente cortos. Estos datos se consideran de calidad superior, ya que son independientes de las limitaciones económicas del muestreo dirigido, utilizan procedimientos normalizados de artes de pesca, y la información biológica sobre las especies se tiene en cuenta durante el diseño de muestreo. Sin embargo, por lo general, tienen una cobertura limitada en el espacio y el tiempo (tanto en términos de estacionalidad y el número de años de datos), lo que podría dar lugar a estimaciones sesgadas e imprecisas. En resumen, hay dos problemas principales con respecto a los datos independientes de la pesca: la del tiempo en relación con el ciclo de las estaciones y la ubicación de las especies objetivo (que conduce a un muestreo representativo, es decir, sesgo) y el hecho de que sólo una cantidad limitada de datos puede ser recogidos. Los datos dependientes de la pesquería suelen proporcionar series temporales mucho más largas, una amplia cobertura espacial durante todo el año, así como información sobre una gran variedad de especies objetivo, artes de pesca, lugares de desembarque y canales de distribución. Los datos de este tipo a veces carecen de detalles específicos, como la ubicación de las zonas de pesca y la identidad de las especies (las capturas son en mucho casos identificados a un nivel taxonómico superior), así como problemas de sesgo debido a las limitaciones impuestas por la dirección y la información errónea deliberada de las capturas. Algunas de las desventajas de los datos dependientes de la pesca se pueden superar mediante el uso de observadores a bordo, pero, inevitablemente, sólo una pequeña parte de la actividad pesquera se puede cubrir de esta manera. Los desembarcos registrados por la FAO son a menudo la única fuente de información disponible debido a su conexión con las actividades económicas. La problemática principal de esta fuente de información es que en muchas pesquerías los desembarcos y las capturas no son necesariamente lo mismo. Grandes cantidades de capturas no declaradas, descartes y capturas ilegales no se registran en los registros de los desembarques, , y no todos los desembarques entran en las estadísticas oficiales (por ejemplo, las ventas directas a los consumidores de individuos que son inferiores a las tallas mínimas, etc.). Además esta topología de datos no tiene ninguna referencia espacial de donde las capturas han sido efectuadas, a diferencia de las dos fuentes de datos precedentemente mencionadas. Sin embargo, los datos recogidos por los observadores a bordo y en campañas científicas disponen de series temporales relativamente recientes, mientras que los datos oficiales de la FAO son disponible (para la mayoría de países de la FAO), desde el 1950 (www.fao.org). La cantidad y calidad de la información varía según el país y las pesquerías estudiadas. En la mayoría de los países, hay información detallada accesible y que además está bien procesada. Aun así existen otros países donde la información es escasa o inexistente. En particular, pero no exclusivamente, los países en desarrollo reflejan estas situaciones de escasez de datos, dado que los recursos y las infraestructuras necesarias para una buena recogida de los datos y para su posterior evaluación de manera, no han aumentado al mismo tiempo que el reciente aumento del comercio internacional de los productos pesqueros. Por otra parte, la necesidad de avanzar hacia un EAFM se ha traducido en un aumento de la necesidad de datos a distintas escalas espacio-temporales y muchas áreas se encuentran actualmente en una situación de escasez datos para su aplicación práctica. Los problemas aumentan cuando el objetivo de los estudios es el análisis de series temporales largas o con una macro escala espacial, con el fin de examinar los cambios en la dinámica de todo un ecosistema. En todos estos casos, donde los modelos ecosistémicos complejos no pueden ser aplicados debido a la falta de datos detallados, el primer paso hacia la aplicación del EAFM es establecer objetivos más realistas y utilizar herramientas flexibles que pueden funcionar con eficacia a pesar de la incertidumbre y la información limitada. Dentro de este contexto, el objetivo principal de esta tesis es analizar las diferentes fuentes de información disponibles sobre los recursos pesqueros, con el fin de proponer nuevas metodologías para una gestión pesquera eficaz tanto en situaciones de escasez de datos, de macro escalas espaciales, de series temporales largas y estudios más detallados. Varios escenarios se han tratado según los datos pesqueros utilizados y el objetivo perseguido. Para cada uno de ellos, una metodología específica ha sido bien desarrollada (cuando no había ningún método disponible) o descrita (cuando ya existía una), mostrando sus ventajas y limitaciones, y explicando cuales podrían ser sus implicaciones para la gestión de la pesca.

• English

  Since ancient times, fishing has been a major source of food for humanity and a provider of employment and economic benefits to those engaged in this activity. However, with increased knowledge and the dynamic development of fisheries it was realized that aquatic resources, although renewable, were not infinite and needed to be properly managed if their contribution to the nutritional, economic and social well-being of the growing world's population was to be sustained. In recent years, world fisheries have become a dynamically developing sector of the food industry, and coastal states have striven to take advantage of their new opportunities by investing in modern fishing fleets and processing factories in response to growing international demand for fish and fishery products. It became clear, however, that many fishery resources could not sustain an often uncontrolled increase in exploitation. Concerns have been expressed about the contribution of fisheries to sustainable development and about overfishing, excess catching capacity, the depletion of some stocks, human-induced changes in ecosystems, as well as the increase and globalization of the fish trade with its potential impact on local supplies and equity. In order to address these problems, the United Nations Food and Agriculture Organization (FAO) has called for the application of an Ecosystem Approach to Fisheries Management (EAFM), which aims to achieve a sustainable exploitation of commercial fisheries, providing specific consideration of the interactions between fishing gears and marine ecosystems. EAFM takes into account that fisheries are embedded into the environment and cannot be managed in isolation. It has to be considered as the application of sustainable development principles to the fishing sector, combining ecological sustainability, economic viability and social fairness. Nevertheless, while it is widely recognized that fishing is important to sustainable development and that its contribution could be improved, the amount of objective scientific information about fishing is limited and what exists is difficult to access. The reliability of scientific advice for the management of natural resources is highly dependent on the quantity and quality of data that are available for scientific assessment and interpretation. Although large amounts of certain types of data about marine ecosystems are readily available, as in the case of satellite-derived remote sensing data or observations based on automatic telemetry, it is far more common to have to deal with limited and irregularly spaced data (e.g. on fish and other marine fauna), and the data may not always be strictly comparable due to variations in environmental conditions between sampling periods. The main reason is that in fishery research the collection of data is both time-consuming and expensive. Data are difficult to obtain, and the problems increase when the goal of the research is to study long time series on a macro-scale, with the purpose of examining changes in the dynamics of a whole ecosystem. In all these cases that require large databases, with an adequate coverage in space and time of a variety of variables, information is almost non-existent. In addition, information about the status of fisheries can be derived from different sources such as fishery-independent surveys, fishery-dependent surveys (skipper logbooks and/or observers) and FAO official landings. Each of these sources provides different types of information with additional details, and must be carefully selected according to the type of study and the objectives pursued. Fishery-independent surveys rely mostly on expensive research campaigns performed over relatively short periods of time. Survey data are considered to be of superior quality because they are independent of management measures, standardized fishing procedures are used, and both sampling statistics and the biological information on target species are taken into consideration during survey design. However, they generally have a limited coverage in space and time (both in terms of seasonality and the number of years of data), which could lead to biased and imprecise estimations. In brief, there are two main issues regarding fishery-independent surveys: the one of timing in relation to the seasonal cycle and location of the target species (leading to unrepresentative sampling, i.e. bias) and the fact that only a limited amount of data can be collected. Fishery-dependent surveys can provide a long time series, wide spatial coverage all year round, and information on a large variety of target species, gear types, landing sites and distribution channels. Data of this kind sometimes lack particular details such as the location of fishing grounds and species identity (catches are mostly identified to a higher taxonomic level), and then there are issues of bias due to constraints imposed by management and the deliberate misreporting of catches. Some of the disadvantages of fishery-dependent surveys can by overcome by using on-board observers but inevitably only a small fraction of fishing activity can be covered in this way. FAO official landings are often the only source of data available due to their connection to the economy and business. The main issue in this source of information is that in many fisheries (official) landings and the actual catch are not necessarily the same. Large amounts of unreported or underreported catches, discards and illegal catches are not recorded in landing data, and not all landings enter official statistics (e.g. black landings, sales by small-scale fisheres directly to consumers, etc.). Furthermore, while previous data sources imply a spatial reference where species have been captured, the FAO official landings have no georeferencing. However, the data collected by on-board observers and that from research surveys have relatively recent time series, while official landing data have been available for most FAO countries since 1950 (www.fao.org). The quantity and quality of information varies depending on the country of the fisheries studied. In most countries, detailed information is available and management processes are in place for some important fisheries, while others are poorly documented and hardly managed at all. In particular, but not exclusively, developing countries reflect these data-poor situations, given that the resources and infrastructure needed to collect relevant data, assess system status and implement management requirements have not increased at the same time as the recent rise international trade in fishery products. Moreover, the need to move towards an EAFM has resulted in an increase in the need for data at different spatio-temporal scales and many areas are currently in a data-poor situation for the purposes of implementing it. The problems increase when the goal is to study long time series on a macro-scale, with the purpose of examining changes in the dynamics of a whole ecosystem. In all these cases, where sophisticated ecosystem models cannot be applied due to the lack of detailed data, the first step towards applying the EAFM should be to set more realistic goals and use flexible tools that can work effectively despite uncertainty and limited information. Within this context, the main aim of this thesis is to analyze the different available sources of information on fishery resources, in order to propose new methodologies for efficient fishery management both in terms of data-poor situations, macro-scale/long time series studies, and micro-meso-scale detailed studies. Several scenarios have been addressed depending on the source of fisheries data used and the objective pursued. For each one of them, a specific methodology has either been developed (when there was no available method) or described (when there was), showing its strengths and limitations, and discussing its implications for the fishery management.

  Since ancient times, fishing has been a major source of food for humanity and a provider of employment and economic benefits to those engaged in this activity. However, with increased knowledge and the dynamic development of fisheries it was realized that aquatic resources, although renewable, were not infinite and needed to be properly managed if their contribution to the nutritional, economic and social well-being of the growing world's population was to be sustained. In recent years, world fisheries have become a dynamically developing sector of the food industry, and coastal states have striven to take advantage of their new opportunities by investing in modern fishing fleets and processing factories in response to growing international demand for fish and fishery products. It became clear, however, that many fishery resources could not sustain an often uncontrolled increase in exploitation. Concerns have been expressed about the contribution of fisheries to sustainable development and about overfishing, excess catching capacity, the depletion of some stocks, human-induced changes in ecosystems, as well as the increase and globalization of the fish trade with its potential impact on local supplies and equity. In order to address these problems, the United Nations Food and Agriculture Organization (FAO) has called for the application of an Ecosystem Approach to Fisheries Management (EAFM), which aims to achieve a sustainable exploitation of commercial fisheries, providing specific consideration of the interactions between fishing gears and marine ecosystems. EAFM takes into account that fisheries are embedded into the environment and cannot be managed in isolation. It has to be considered as the application of sustainable development principles to the fishing sector, combining ecological sustainability, economic viability and social fairness. Nevertheless, while it is widely recognized that fishing is important to sustainable development and that its contribution could be improved, the amount of objective scientific information about fishing is limited and what exists is difficult to access. The reliability of scientific advice for the management of natural resources is highly dependent on the quantity and quality of data that are available for scientific assessment and interpretation. Although large amounts of certain types of data about marine ecosystems are readily available, as in the case of satellite-derived remote sensing data or observations based on automatic telemetry, it is far more common to have to deal with limited and irregularly spaced data (e.g. on fish and other marine fauna), and the data may not always be strictly comparable due to variations in environmental conditions between sampling periods. The main reason is that in fishery research the collection of data is both time-consuming and expensive. Data are difficult to obtain, and the problems increase when the goal of the research is to study long time series on a macro-scale, with the purpose of examining changes in the dynamics of a whole ecosystem. In all these cases that require large databases, with an adequate coverage in space and time of a variety of variables, information is almost non-existent. In addition, information about the status of fisheries can be derived from different sources such as fishery-independent surveys, fishery-dependent surveys (skipper logbooks and/or observers) and FAO official landings. Each of these sources provides different types of information with additional details, and must be carefully selected according to the type of study and the objectives pursued. Fishery-independent surveys rely mostly on expensive research campaigns performed over relatively short periods of time. Survey data are considered to be of superior quality because they are independent of management measures, standardized fishing procedures are used, and both sampling statistics and the biological information on target species are taken into consideration during survey design. However, they generally have a limited coverage in space and time (both in terms of seasonality and the number of years of data), which could lead to biased and imprecise estimations. In brief, there are two main issues regarding fishery-independent surveys: the one of timing in relation to the seasonal cycle and location of the target species (leading to unrepresentative sampling, i.e. bias) and the fact that only a limited amount of data can be collected. Fishery-dependent surveys can provide a long time series, wide spatial coverage all year round, and information on a large variety of target species, gear types, landing sites and distribution channels. Data of this kind sometimes lack particular details such as the location of fishing grounds and species identity (catches are mostly identified to a higher taxonomic level), and then there are issues of bias due to constraints imposed by management and the deliberate misreporting of catches. Some of the disadvantages of fishery-dependent surveys can by overcome by using on-board observers but inevitably only a small fraction of fishing activity can be covered in this way. FAO official landings are often the only source of data available due to their connection to the economy and business. The main issue in this source of information is that in many fisheries (official) landings and the actual catch are not necessarily the same. Large amounts of unreported or underreported catches, discards and illegal catches are not recorded in landing data, and not all landings enter official statistics (e.g. black landings, sales by small-scale fisheres directly to consumers, etc.). Furthermore, while previous data sources imply a spatial reference where species have been captured, the FAO official landings have no georeferencing. However, the data collected by on-board observers and that from research surveys have relatively recent time series, while official landing data have been available for most FAO countries since 1950 (www.fao.org). The quantity and quality of information varies depending on the country of the fisheries studied. In most countries, detailed information is available and management processes are in place for some important fisheries, while others are poorly documented and hardly managed at all. In particular, but not exclusively, developing countries reflect these data-poor situations, given that the resources and infrastructure needed to collect relevant data, assess system status and implement management requirements have not increased at the same time as the recent rise international trade in fishery products. Moreover, the need to move towards an EAFM has resulted in an increase in the need for data at different spatio-temporal scales and many areas are currently in a data-poor situation for the purposes of implementing it. The problems increase when the goal is to study long time series on a macro-scale, with the purpose of examining changes in the dynamics of a whole ecosystem. In all these cases, where sophisticated ecosystem models cannot be applied due to the lack of detailed data, the first step towards applying the EAFM should be to set more realistic goals and use flexible tools that can work effectively despite uncertainty and limited information. Within this context, the main aim of this thesis is to analyze the different available sources of information on fishery resources, in order to propose new methodologies for efficient fishery management both in terms of data-poor situations, macro-scale/long time series studies, and micro-meso-scale detailed studies. Several scenarios have been addressed depending on the source of fisheries data used and the objective pursued. For each one of them, a specific methodology has either been developed (when there was no available method) or described (when there was), showing its strengths and limitations, and discussing its implications for the fishery management.