Application of a bioeconomic model for supporting the management process of the small pelagic fishery in the Veneto Region, northern Adriatic Sea, Italy

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Balancing ecology, economy and culture in fisheries policy: Participatory research in the Western Mediterranean demersal fisheries management plan

Fishing communities in the Mediterranean Sea face challenges in dealing with Common Fisheries Policy (CFP) ecosystem-based management measures aimed at reducing fishing effort and implementing partial closures of fisheries. The Participatory Action Research method is used here as a "pilot experience" to gather reactions from fishers, scientists and fisheries managers to the Western Mediterranean Multi-Annual Demersal Fisheries Plan (WM MAP) by identifying needs and concerns, but also alternatives to maintain the viability of the fishery. The data gathering process consisted on a structured questionnaire administered during a workshop to 40 stakeholders involved in Spanish fisheries in the Mediterranean, followed by an open discussion session. The results show that fishers disagree with the new regulations, which they perceive as yet another layer of restrictive regulations for an industry that faces major challenges and currently has low profitability, whereas scientists tended to agree more with the WM MAP than the administration or the fishers. Nevertheless, all stakeholders agree that the values of the cultural heritage of fisheries and the exploration of alternative marketing systems should balance the productivity-based approach to fisheries policies followed so far, that have shown signs of failure. According to stakeholder perceptions, this would improve the economic and social viability of fisheries, as well as highlight the value of fishing activity and its social prestige. Integrating the value of cultural heritage and post-production processes into the CFP would improve stakeholder involvement in fisheries policies. Through participatory research methods the ecosystem-based management approach could be embedded in a community-based approach, integrating its social actors in a proactive attitude and considering fisheries as a human activity socially and culturally rooted in the environment, which would enhance the effective implementation of fisheries policies

Ocurrencia de anchoa adulta en Cataluña (Mediterráneo noroccidental) en relación a las condiciones superficiales del mar

Generalized additive and generalized additive threshold models were used to study the relationship between landings per unit effort (LPUE) of anchovy, Engraulis encrasicolus, during the spawning season (May-October) from 2000-2010, and environmental variables, using sea surface data derived from satellite imagery (temperature, salinity, chlorophyll a, and meridional and zonal velocity current) in three fishing zones defined along the Catalan coast. The configuration of the environment where spawning aggregations occur affects early life stages and therefore the future demographic structure of the population. It is therefore fundamental to define the environmental conditions and their variations during the spawning season. Our results show that the low salinity in the Northern and Central sector and the velocity of the zonal and meridional currents in the Central and Southern sector, respectively, implicated in retention processes, increase LPUE during the spawning period. Temperature was related to LPUE in the Southern and in the Northern sectors, in both of which a non-linear positive effect with a local maximum peak at lower temperature values was present. However, in the Northern sector, this relationship held only for the period before 2007. After 2007 the decrease in preferred temperature suggests a reduction of the thermal window in which adult spawner aggregations occur. In agreement with previous studies on this species, the relationships were non-linear, stressing the importance of the match in timing and location between favourable conditions and spawning period as a crucial event for understanding the dynamics of small pelagics populations.Con el objeto de estudiar la relación entre descargas por unidad de esfuerzo (LPUE) de la anchoa, Engraulis encrasicolus, durante la época de puesta (Mayo-Octubre) y variables ambientales marinas obtenidas por observación de satélite (temperatura, salinidad, clorofila-a, velocidad de corriente zonal y meridional) se analizaron series de datos para el periodo 2000-2010 mediante modelos aditivos generalizados, con y sin umbral, en tres zonas de pesca de la costa catalana. La configuración del ambiente en que ocurren las agregaciones de puesta afecta a los estadios tempranos y, por consiguiente, a la estructura demográfica futura de las poblaciones. Por lo tanto es de gran importancia definir las condiciones ambientales y sus variaciones durante la época de puesta. Los resultados del análisis muestran que bajas salinidades en los sectores norte y central, y las velocidades zonal y meridional de la corriente, en los sectores central y sur respectivamente, implicadas en los procesos de retención hacen aumentar la LPUE durante el periodo de puesta. La temperatura se relacionó con la LPUE en los sectores sur y norte. En ambas zonas se observó un efecto positivo y no lineal con un pico máximo a valores de temperatura bajos. Sin embargo, en el sector norte esta relación se mantuvo solamente hasta 2007. Después de 2007, la disminución en la temperatura preferencial sugiere una reducción en la ventana térmica en la que ocurren las agregaciones de puesta. Las relaciones obtenidas son no lineales, coincidiendo con estudios previos en esta especie, haciendo resaltar la importancia del ajuste espacio-temporal entre condiciones favorables y periodo de puesta como evento crucial para entender la dinámica poblacional de los pequeños pelágicos

Virtual population analysis of two snapper species, Lutjanus analis and Lutjanus chrysurus, caught off Pernambuco State, north-eastern Brazil

Foi aplicado a Análise Virtual de População - VPA em estado estacionário a dois estoques de lutjanídeos (Lutjanus analis e L. chrysurus) explorados pela frota artesanal de linha de mão ao longo da costa do Estado de Pernambuco (Nordeste do Brasil). Demonstrou-se que mesmo para uma série de dados não-históricos (1 ano de amostragem) pode-se produzir um diagnóstico útil dos recursos pesqueiros e que ambos os estoques estão próximo ao estado de sobrexplotação e melhor rendimento por recruta seria obtido com uma redução do esforço de pesca de 16% para L. analis e de 43% para L. chrysurus. Dado a impraticabilidade de ordenar os dois estoques separadamente, propõe-se uma diminuição do esforço de pesca em 25% para a frota de linha de mão. Incorporando os resultados de VPA em estratégias de simulação, pôde-se desenvolver uma comparação dos prováveis resultados das diferentes opções de regulamentação pesqueira (regulamento do esforço) baseadas em 3 simples indicadores (biomassa do estoque reprodutor por recruta, biomassa por recruta e rendimento por recruta). Compararam-se os resultados da redução do esforço com o aumento do esforço (25%) através de uma análise de simulação. Admitindo as dificuldades em testar as suposições introduzidas em nosso modelo (estado estacionário, modelo de recrutamento de Beverton e Holt) e usando técnicas de análise padrão de pescarias, mostrou-se que medidas adequadas à regulamentação pesqueira podem ser obtidas, mesmo em um contexto de dados limitados. Fornecer recomendações às pescarias costeiras de países em desenvolvimento é uma prioridade, dada a elevada dependência das comunidades pesqueiras locais nos recursos vivos costeiros e do crescente esforço de pesca aplicado por uma população de crescimento.We applied steady-state Virtual Population Analysis - VPA to two stocks of snappers (Lutjanus analis and L. chrysurus) exploited by artisanal hand-line fleets along the Pernambuco State coast (North-eastern Brazil). We show that even short-data series (1 year of sampling) can produce a useful diagnosis of fisheries resources. Both stocks are slightly overexploited by the hand-line fishery and a higher yield-per-recruit would be obtained by a reduction of effort of 16% for L. analis and 43% for L. chrysurus. Given the impracticability of managing the two stocks separately, we propose a 25% decrease of fishing effort for the hand-line fleet. By incorporating the results of VPA into a simulation framework, we can develop a comparison of the likely result of different policy options (effort regulation) based on 3 simple indicators (Spawning stock biomass-per-recruit, biomass-perrecruit and yield-per-recruit). We compare the results of effort reduction with those of effort increase (25%) through simulation analysis. Allowing for the difficulty of testing assumptions introduced in our model (steady-state, Beverton and Holt recruitment model) and using standard fisheries analysis techniques, we show that useful fisheries advice can be produced even in a context of limited data. Providing advice to developing countries coastal fisheries is an urgent issue, given the high dependence of local communities on coastal living resources and the increasing fishing effort applied by a growing population

On the economic nature of consumers\u2019 willingness to pay for a selective and sustainable fishery: A comparative empirical study

Special issue on Discards regulation vs Mediterranean fisheries sustainability.-- 6 pages, 2 tables[EN] The EU Landing Obligation (LO) bans discards to incentivize a more selective and sustainable fishery. This regulation may induce a cost to the fishing industry that could be transferred to final fish consumers. We aim to assess the consumers’ reservation price for a sustainable and selective fishery. The methodology follows two steps: We first assess the value of the reservation price (willingness to pay, WTP) for a sustainable and selective fishery by using contingent valuation methods from a comparative perspective in Spain and Italy. We then attempt to empirically assess the components of WTP by using an original model specification that, unlike those presented in the literature, exogenizes socio-economic variables and uses ideological indicators to explain WTP in a two-line simultaneous model estimated by instrumental variable regression. The results show a positive, though low, WTP across the two samples, and very different impacts of estimated coefficients on the WTP for the two samples. A preliminary interpretation of this divergence highlights that Italian consumers consider LO-incentivized sustainable fishery a pure public good linked to issues of legality, and Spanish consumers consider it an impure public good linked to environmental issues. These differences may indicate how strongly the institutions and the policies in each region are perceived by a different human capital structure. They may also indicate that the problem, the perceptions of it and the solutions to it differ according to the context[ES] La obligación de desembarque de la Unión Europea (LO) prohíbe los descartes para incentivar una pesquería más selectiva y sostenible. Esta regulación puede inducir costes a la industria pesquera que a su vez pueden ser transferidos al consumidor final. Nuestro objetivo es evaluar el precio de reserva del consumidor para una pesquería más sostenible y selectiva. La metodología se basa en dos fases: primero, evaluamos el precio de reserva (disposición a pagar, WTP) para una pesquería sostenible y selectiva mediante métodos de valoración contingente (CV) en un estudio comparativo entre España e Italia. En una segunda fase intentamos estimar empíricamente los componentes de esta WTP mediante la especificación original de un modelo que, a diferencia de la literatura existente, exogeniza las variables socioeconómicas y usa indicadores ideológicos para explicar la WTP, en una regresión bi-funcional con variables instrumentales (IV). Los resultados muestran una WTP positiva, aunque reducida, en ambas muestras, y permiten deducir un impacto distinto de los coeficientes estimados en la WTP. La interpretación preliminar de esta divergencia hace destacar que los consumidores italianos consideran como un bien público puro a una pesquería sostenible incentivada mediante LO, relacionado con aspectos de legalidad, mientras que los consumidores españoles consideran ese modelo de pesquería como un bien público impuro, relacionado con conservación ambiental. Estas diferencias pueden indicar la fortaleza con la que dos estructuras distintas de capital humano perciben las instituciones y las políticas de cada región. También sugieren una distinta percepción, existencia y solución del problema en un contexto distintoThis research was funded by EU H2020 Research and Innovation Action “MINOUW” (contract nº 634495)Peer reviewe

Mejorando la vitalidad a bordo posterior a la captura de la cigala descartada (Nephrops norvegicus) para una pesca de arrastre más sostenible en el Mediterráneo

The current European Union fisheries policy encourages improving handling practices to increase the survival of discards. Trawling on the Mediterranean upper slope often generates over 30% of discards of the total catch. Among other species, Nephrops norvegicus juveniles are abundantly returned to the sea, sometimes exceeding 40% of discarded biomass. N. norvegicus discard survival probability has been recently shown to be related to vitality on board and to vary seasonally, being especially low during the summer (0.06). Environmental characteristics (especially, high on-deck temperature in summer) make it necessary to improve vitality on board in order to increase discard survival. We therefore tested new discard handling methodologies for a Mediterranean mixed trawl fishery, with N. norvegicus as the target species. The results showed a survival rate on board higher than 0.8 resulting from vitality status improvements achieved by immersing N. norvegicus in cooled seawater on board during the catch selection and discard time. The implementation of this method would make an important contribution to more sustainable Mediterranean trawl fisheries.La política pesquera actual de la Unión Europea fomenta la mejora de las prácticas de manipulación de los descartes para aumentar su supervivencia. La pesca de arrastre en el talud superior del Mediterráneo, suele generar más del 30 % de los descartes de la captura total. Entre otras especies, los juveniles de Nephrops norvegicus son devueltos en gran abundancia al mar, a veces llegando a superar el 40% de la biomasa descartada. Recientemente se ha demostrado que la probabilidad de supervivencia al descarte de N. norvegicus está relacionada con la vitalidad a bordo y varía estacionalmente, siendo especialmente baja durante el verano (0,06). En este contexto, probamos y proponemos nuevas metodologías de manipulación de los descartes para una pesquería de arrastre mixta en el Mediterráneo, con N. norvegicus como especie objetivo, ya que las características ambientales (especialmente, la alta temperatura en cubierta en verano) hacen necesario mejorar la vitalidad a bordo de los descartes, para aumentar su supervivencia. Los resultados mostraron una tasa de supervivencia a bordo superior a 0,8 debido a las mejoras en el estado de vitalidad al sumergir N. norvegicus en agua de mar enfriada, durante la selección de capturas y el tiempo de descarte. La implementación de esta metodología, que mejora la vitalidad a bordo, es relevante para conseguir pesquerías de arrastre más sostenibles en el Mediterráneo

Evaluación crítica de la comprensión y del conocimiento actuales en el contexto de una aproximación ecosistémica a la gestión pesquera en el Mar Mediterráneo y el Mar Negro

A critical review was carried out involving experts from 17 countries, to identify, summarize and evaluate the current understanding related to the Ecosystem Approach to Fisheries management (EAF) in the Mediterranean and Black Seas. The existing information available at country level, coming from research and monitoring projects and other types of activities, was explored. The evaluation was done following a standardized protocol and using simple semi-quantitative methods. The results highlighted an overall low-medium degree of fulfilment of the requirements of the EAF, with some differences related to the different issues considered. The highest scores were reported for the knowledge related to fleet structure/ behaviour and species/habitat distribution, whereas the lowest scores were reported for modelling, and socio-economic and management issues. Although only semi-quantitative, these results provided an initial picture at a broad regional level on the state of knowledge with a view to a proper implementation of the EAF in the Mediterranean and Black Seas, and identified gaps in scientific knowledge that should be covered.Se llevó a cabo una revisión crítica con la intervención de expertos de 17 países para la identificación, resumen y evaluación del conocimiento actual en relación a la Aproximación Ecosistémica a la Gestión Pesquera (EAF) en el Mar Mediterráneo y el Mar Negro. Se explora la información existente a nivel de cada país, derivada de proyectos de investigación y seguimiento, así como otros tipos de actividades. Se llevó a cabo una evaluación siguiendo un protocolo estandardizado y el uso de métodos semi-cuantitativos. Los resultados muestran que en general el grado de cumplimiento con los requerimientos de EAF es bajo-medio, con algunas diferencias relacionadas con los distintos aspectos considerados. Las puntuaciones más elevadas correspondieron al conocimiento relacionado con la estructura de flota y su comportamiento, así como con la distribución espacial de hábitats y especies. Las puntuaciones más bajas correspondieron a aspectos relacionados con la modelización, la socio-economía y la gestión. A pesar de su carácter semi-cuantitativo, estos resultados proporcionan una primera imagen a nivel regional del estado de conocimiento del que se parte para una implementación adecuada de EAF en el Mar Mediterráneo y el Mar Negro y ayuda a identificar las carencias en el conocimiento científico que deben ser corregidas

Bioeconomic simulation analysis of hake and red mullet fishery in the Gulf of Saronikos (Greece)

[EN] Hake (Merluccius merluccius) and red mullet (Mullus barbatus) are two of the most important species in Greek fisheries due to their high commercial interest. Both have been reported to be overexploited and in need of management to preserve the continuity of their exploitation. Hake is exploited by trawlers and red mullet by both trawlers and beach seiners in Saronikos Gulf (Greece). The MEFISTO bioeconomic simulation model is applied in order to test the interaction between trawlers and beach seiners through the age-specific fishing mortality applied by each fleet to the red mullet stock. The effects of the withdrawal of some beach seiners in 2002 and the increase in trawl mesh size that has already been implemented (from 28 mm to 40 mm stretched mesh) are tested jointly with alternative management scenarios such as the complete withdrawal of beach seiners and effort reduction in trawler activity. The analysis of the simulation results is based on the evolution of biological and economic indicators through 15-year stochastic projections. It is shown that limiting fishing effort and improving selectivity patterns of the trawl fleet would be beneficial for the recovery of the populations and for the profitability of the fishery. In addition to the increase in trawl mesh size, a further fishing effort reduction of 12% is recommended for the trawling fleet. Conversely, limiting or completely removing the beach seiner fleet would protect red mullet juveniles but would not significantly increase the profitability of the trawling fleet, and it would cause unemployment[ES] La merluza (Merluccius merluccius) y el salmonete (Mullus barbatus), debido a su gran interés comercial, son las dos especies más importantes de las pesquerías griegas. Ambas especies se encuentran en situación de sobreexplotación y necesitadas de una gestión adecuada que proteja la continuidad de su explotación. En el Golfo de Saronikos (Grecia), la merluza es explotada por la flota de arrastre mientras que el salmonete lo pescan las flotas de arrastre y la de cerco de playa. Se utiliza el modelo de simulación MEFISTO para el análisis de la interacción de ambas flotas a través de las mortalidades pesqueras aplicadas sobre las clases de edad del salmonete. En el presente trabajo se evalúan los efectos de la retirada de algunos cerqueros que tuvo lugar en 2002 y del incremento del ancho de malla (desde 28 mm a 40 mm) que tuvo lugar en 2000, así como algunos escenarios de gestión alternativos como la completa retirada de la flota de cerco o la reducción del esfuerzo pesquero de la flota de arrastre. El análisis de las simulaciones estocásticas se presenta a través de la evolución de los indicadores bioeconómicos durante 15 años. Se muestra que la limitación del esfuerzo pesquero y la mejora en los parámetros de selectividad de la flota de arrastre serían beneficiosos tanto desde un punto de vista económico como conservacionista. Por otro lado, se recomienda una reducción de esfuerzo del 12%. Por el contrario, la limitación o retirada de la flota de cerco de playa causaría un problema de desempleo y no permitiría aumentar los beneficios de la flota de arrastre, sin llegar a ser beneficioso para las poblaciones explotadasWe thank Triantafyllos Kountouris and Argyris Argyrokastritis for their help and advice in the in situ approach to the hake and red mullet fishery in the Gulf of Saronikos and all the staff in the Fisheries Laboratory of the Ministry of Rural Development and FoodPeer reviewe

Estimation et analyse bio-économique d'une pêche au trémail de l'île de Majorque (NO Méditerranée)

9 pages, 9 figures, 6 tables.[EN] Trammel net is the main fishing gear used by artisanal fishers in Majorca Island (NW Mediterranean), and is representative of Mediterranean small-scale fisheries using static gear. The use of static gears close to the coast, where seasonal variability and spatial heterogeneity are high, promotes the diversification of fishing practices or metiers. We analyze the seasonal dynamics of the nets used, target species (red and black scorpionfish, red mullet and cuttlefish) exploitation patterns and the socio-economic conditions under which this fishery takes place, based on General Fisheries Directorate daily sale records (2002-2006). Additional personal socioeconomic interviews allowed the characterization of the trammel net fishery, its fishing behaviour, cost structure and conflicts. Catch and effort data and market surveys are used to evaluate the level of exploitation of the target species and allowed describing Majorca trammel net fishery as an activity based on a sustainable resource. The main target species were found to be near their maximum sustainable yield both by means of a surplus production model (with parameters estimated by CEDA-Catch Effort Data Analysis, software) and an age structured assessment model based on yield-per-recruit analysis. Management actions currently debated by local administration and fishers focus on improving fishers' economic situation, rather than on protecting a threatened resource. One of the management actions proposed is a one day effort reduction, which was analyzed here with the help of a bioeconomic simulation model. A 15-year (2005-2020) simulation allows providing advice to local managers to focus on the commercialization aspects, in order to obtain a higher value to the fish production, rather than expecting to obtain higher profits only by a reduction of the offer.[FR] Le filet trémail est le principal engin de la pêche artisanale utilisé par les pêcheurs de l'île de Majorque (NO Méditerranée) ; il est représentatif de la petite pêche en Méditerranée, utilisant des engins dormants. L'usage de ces engins dormants à proximité de la côte, où la variabilité saisonnière et l'hétérogénéité spatiale sont élevées, entraîne la diversification des pratiques de pêche ou métiers. Nous analysons la dynamique saisonnière des filets utilisés, les espèces-cibles (rascasse rouge, rascasse blanche, le mulet barbet et la seiche), les modèles d'exploitation et les conditions socio-économiques sous lesquelles la pêcherie se développe, basées sur les données des ventes journalières de la Direction Générale des Pêches (2002-2006). Des enquêtes socio-économiques ont permis de caractériser la pêcherie au trémail, les comportements de pêche, la structure des coûts et les conflits. Les données d'effort et de capture et l'étude du marché sont utilisées pour évaluer le niveau d'exploitation des espèces-cibles et permettent de décrire la pêcherie au trémail de Majorque comme une activité basée sur des ressources à l'équilibre. Les principales espèces-cibles sont trouvées proches de leur rendement maximum à l'équilibre, à la fois au moyen d'un modèle de surplus de production (avec des paramètres estimés au moyen du logiciel CEDA, Catch Effort Data Analysis) et par un modèle d'estimation structurée en âge, basé sur l'analyse des rendements par recrue. La gestion couramment débattue par l'administration locale et les pêcheurs se focalisait sur l'amélioration de la situation économique des pêcheurs plutôt que de protéger une ressource en danger. Une des actions de gestion proposée est une réduction de l'effort - un jour de pêche, qui peut être analysée ici avec l'aide d'un modèle de simulation bio-économique. Une simulation sur 15 ans (2005-2020) permet de fournir des conseils aux gestionnaires locaux sur les aspects de commercialisation, en vue d'obtenir une plus haute valeur de production de poissons, plutôt que d'espérer obtenir des profits plus élevés par une réduction de l'offre seulement.This study was funded by the Commission of the European Communities, specific RTD programme “Specific Support to Policies”, SSP-2004-22745 “Probabilistic assessment, management and advice model for fishery management in the case of poor data availability” (POORFISH).Peer reviewe