Evaluación bioeconómica del cambio en la selectividad de un arte de pesca: el caso de una flota mono-específica afectada por la obligación de desembarque

The European Union Common Fisheries Policy has established a discard ban, which states that fish below a reference size cannot be sold directly for human consumption. In a fishing effort-regulated fishery, the discard ban can result in extra handling, storing and landing costs. In an output-regulated fishery, this policy might also limit the effort levels as all the catches count against the quota. In both cases, this regulation can reduce the economic performance of the companies, even in single-species fisheries. A possible solution is to increase the mesh size, thus retaining fewer small individuals. To study this option, a bioeconomic simulation of a change in the gear selectivity from 100- to 120-mm minimum mesh size (MMS) was performed. The results show that the private perspective (profits) does not change. Furthermore, due to the lower retention of 120 mm MMS, the efficiency of a fishing day was reduced by 5% and 2.5%, from the point of view of capital and labour productivity, respectively. In contrast, gross revenues increased by 1.5% and crew compensation by 2%. Given a societal benefit of this change in the mesh size, this gain could be re-distributed to provide an incentive for selectivity improvements.La Política Pesquera Común de la Unión Europa ha introducido la prohibición de descartar, estableciendo que todo pescado por debajo de una talla de referencia no puede ser vendido para consumo humano directo. En una pesquería regulada a través de limitaciones del esfuerzo de pesca, la prohibición de descartar puede generar sobrecostes de manipulación, almacenamiento y desembarque adicionales. En una pesquería regulada a través de límites en las capturas, esta política podría incluso limitar los niveles de esfuerzo ya que todas las capturas deben ser deducidas de la cuota. En ambos casos, esta regulación puede reducir el resultado económico de las empresas, incluso en el caso de una pesquería mono-específica. Una posible solución sería aumentar el tamaño mínimo de la malla, y así reducir la retención de los individuos más pequeños. Con el fin de estudiar esta opción, se ha realizado una simulación bioeconómica de un cambio en el tamaño mínimo de la malla de 100 a 120-mm. Los resultados muestran cómo la perspectiva económica privada (beneficios) no varía. Más aun, debido a la menor retención de la malla de 120 mm, la eficiencia de un día de pesca se ve reducida en un 5% y en un 2.5%, desde el punto de vista de la productividad del capital y del trabajo, respectivamente. Por el contrario, los beneficios brutos aumentan un 1.5% y la remuneración al trabajo en un 2%. Debido a la existencia de un beneficio social, la ganancia podría ser redistribuida para así ofrecer un incentivo a esta mejora de la selectividad

Measuring the value of ecosystem-based fishery management using financial portfolio theory

We highlight the potential benefits of adopting Ecosystem-based Fishery Management (EBFM). We compare the EBFM implementation with the more traditional single-stock approach. We show the contribution of the portfolio theory to the EBFM, which can be achieved by selecting an optimal portfolio to maximise the average revenues and minimise the variance. We use this approach to construct two frontiers: the ecosystem efficient frontier, which considers stock interactions (the variance-covariance matrix), and the stock efficient frontier,only considering individual stock variances. We also define two risk gaps. The first gap shows the reduction in the standard deviation per unit of revenuethat the fleet could have achieved if they had decided to use the optimal portfolio of the stock frontier instead ofthe historical portfolio. The second gap reflects the reduction in the standard deviation per unit of revenue when the management moves from the stock frontier to the ecosystem frontier portfolio. This approach is adapted to the Basque inshore fleet. According to our results, taking the single-stock approach as the benchmark, the EBFM would obtain the same historical revenue while reducing the risk by 23%.Alternatively, allowing the same level of risk, it could achieve a 21% increase in revenues.This work has received funding from Basque Government Department of Education (Grant IT-799-13). I. Carmona has benefited from a grant of the Department of Economic Development and Competitiveness of the Basque Government. A. Ansuategi, J.M. Chamorro and M. Escapa also thank financial support from the University of the Basque Country (Grant GIU 18-136) and from the Spanish Ministry of Science, Innovation and Universities (Grant RTI2018-093352-B-I00)

The bad, the good and the very good of the landing obligation implementation in the Bay of Biscay: A case study of Basque trawlers

Landing obligation (LO) has become a core element on the Common Fisheries Policy (CFP). In this work a bioeconomic simulation tool is used to anticipate the effects of LO in a particular fleet that by its nature is likely to be highly affected by its implementation. These effects are measured in terms of biologic, economic and fleet indicators. Results show how LO has a negative short term effect in the economic performance of the fleet (the bad). That the exemption and flexibilities foreseen in the CFP alleviate, in the short term, the effects of the choke species and the redistribution effects created (the good). Furthermore, results show that there are private incentives to improve the selectivity and to reduce the discard levels of the fleets. It is concluded how a breeding ground for a more sustainable and productive system is created (very good)