Bioeconomic assessment of a change in fishing gear selectivity: the case of a single-species fleet affected by the landing obligation

Abstract

Summary: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.Keywords: minimum mesh size; landing obligation; minimum conservation reference size; simulation model; selectivity; hake.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 Resumen: 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.Palabras ...

Bioeconomic analysis of the effects of modifying the trawl extension piece with T90 netting

“…Colloca et al (2014) recommended changes in the selectivity patterns to decrease fishing mortality and delay the age at first capture as a more practical and efficient way to recover Mediterranean fish stocks than mere effort-reduction measures. Additionally, in light of the current Common Fisheries Policy, in which a ban of discards on regulated species can provide additional incentives for improving fisheries selectivity (Prellezo et al 2016(Prellezo et al , 2017, our results show that it is possible to reduce fishing mortality and contribute to stock rebuilding by relatively simple, inexpensive modifications to trawl nets that enhance size selectivity.…”

“…Selectivity improvements inevitably have short-term negative consequences for the fisheries operators' profitability, and consequently a low incentive for adoption, but will in the long term help rebuild stocks and produce higher yields, particularly in heavily overexploited resources such as Mediterranean stocks (Colloca et al 2014). On the other hand, the analysis of the Basque trawl fishery in the Bay of Biscay by Prellezo et al (2016Prellezo et al ( , 2017 showed that private incentives can arise to improve the selectivity and reduce discards through the adoption of more selective fishing gear by fishers as a logical outcome of the LO, on bioeconomic grounds only. Naturally, any modifications to the current trawl design should be practical and inexpensive to facilitate its wide and fast adoption by fishers.…”

Bioeconomic Analysis of the EU Multiannual Management Plan for Demersal Fisheries in the Western Mediterranean. Spanish Fisheries as a Case Study

“…Dashed lines indicates the FMSY level and SSBlim (computed as SSBlim = 1.4*SSBmin, where SSBmin is the minimum value of SSB observed in the historical data series). Gullestad et al, 2015;Sardà et al, 2015;Prellezo et al, 2017). Moreover, improving selectivity would modify reference points and decrease the current levels of fishing mortality on F MSY (Scott and Sampson, 2011).…”

Use of avoidance behaviours to reduce the economic impacts of the EU Landing Obligation: the case study of a mixed trawl fishery

“…To comply with these constraints, fishers' interests are to reduce bycatch (i.e., unwanted catch) through more selective fishing practices. The development of selective fishing gears is extensively studied (Alzorriz et al, 2016;Batsleer et al, 2016;Mortensen et al, 2017;Prellezo et al, 2017;Kopp et al, 2018), but it requires time, important financial resources and is hardly achieved in mixed-fisheries (Suuronen and Sardà, 2007;Catchpole et al, 2008;Romero et al, 2010). Another possibly complementary approach consists in allocating fishing effort to other species, fishing grounds or seasons to avoid bycatch (e.g., Batsleer et al, 2013;Branch and Hilborn, 2008;Simons et al, 2015).…”