Economic expenditures by recreational anglers in a recovering atlantic bluefin tuna fishery.

The recent return of Atlantic bluefin tuna to northern Europe following the recovery of the east Atlantic stock has sparked substantial public and scientific interest. This is particularly true for recreational anglers in Denmark, who often consider Atlantic bluefin tuna to be the catch of a lifetime. This attitude has previously sustained a substantial recreational fishery for bluefin tuna with annual tournaments in Denmark, which peaked in the 1950s before the subsequent collapse of the stock during the 1960s. Several scientific tagging programs have recruited recreational anglers in recent years to help catch and release tagged bluefin tuna. The anglers' investment of time and money in the scientific tagging projects indicate that the recreational fishery could recover in the future. However, the economic aspects of a potential future recreational bluefin tuna fishery remain unknown. We surveyed anglers participating in a scientific catch and release bluefin tuna fishery in Denmark across three years (2018-2020) and calculated the total annual expenditures associated with the activities. Additionally, we estimated the magnitude of the negative impact (i.e., incidental mortalities) on the bluefin tuna stock. Our results show that total annual expenditures by the recreational anglers approached 1,439,540€, totaling 4,318,620€ between 2018 and 2020. We found that recreational bluefin tuna anglers had mean annual expenditures directly related to the bluefin tuna fishing between 7,047€ and 2,176€ with an associated mortality impact on the stock of less than 1 tonne annually. By comparing the mortality impact to the expenditures, we estimate that each dead Atlantic bluefin tuna during the three study years generated 398,163€ in mean annual expenditures, equivalent to approximately 1636€ kg-1. Our study demonstrates significant economic expenditures among recreational anglers who target Atlantic bluefin tuna. This provides a clear example of how a recovery of marine natural capital and related ecosystem services can support development in the blue economy.

Using ecosystem-services assessments to determine trade-offs in ecosystem-based management of marine mammals.

The goal of ecosystem-based management (EBM) is to support a sustainable and holistic multisectored management approach, and is recognized in a number of international policy frameworks. However, it remains unknown how these goals should be linked to assessments and management plans for marine fauna, such as mammals and fish stocks. It appears particularly challenging to carry out trade-off analyses of various ocean uses without a framework that integrates knowledge of environmental, social, and economic benefits derived from nonstationary marine fauna. We argue this gap can be filled by applying a version of the ecosystem-service approach at the population level of marine fauna. To advance this idea, we used marine mammals as a case study to demonstrate what indicators could operationalize relevant assessments and deliver an evidence base for the presence of ecosystem services and disservices derived from marine mammals. We found indicators covering common ecosystem service categories feasible to apply; examples of indicator data are already available in the literature for several populations. We encourage further exploration of this approach for application to marina fauna and biodiversity management, with the caveat that conceptual tensions related to the use of the ecosystem service concept itself needs to be addressed to ensure acceptance by relevant stakeholders.

Uso de Evaluaciones de Servicios Ambientales para Determinar las Compensaciones en el Manejo de Mamíferos Marinos Basado en Ecosistemas Resumen El objetivo del manejo basado en ecosistemas (EBM) es respaldar una estrategia de manejo multisectorial sustentable y holística, objetivo que es reconocido dentro de varias políticas de marcos de trabajo internacional. Sin embargo, todavía desconocemos cómo deben vincularse este objetivo con las evaluaciones y los planes de manejo de la fauna marina, como los mamíferos y las poblaciones ícticas. Actualmente, parece un reto realizar los análisis de las compensaciones de varios usos oceánicos sin un marco de trabajo que integre el conocimiento sobre los beneficios ambientales, sociales y económicos derivados de la fauna marina no estacionaria. Discutimos que este vacío puede completarse con la aplicación de una versión de la estrategia de servicio ambiental a nivel poblacional para la fauna marina. Para impulsar esta idea usamos mamíferos marinos como estudio de caso para demostrar cuáles indicadores podrían poner en práctica evaluaciones relevantes y entregar una base de evidencias para la presencia de servicios y perjuicios ambientales derivados de los mamíferos marinos. Descubrimos indicadores que cubren las categorías de servicios ambientales comunes cuya aplicación es factible; los ejemplos de datos indicadores ya se encuentran disponibles en la literatura para varias de las poblaciones. Alentamos una exploración más profunda de esta estrategia para su aplicación en la fauna marina y el manejo de biodiversidad, bajo advertencia de que las tensiones conceptuales relacionadas con el uso del concepto de servicio ambiental necesitan ser tratadas para asegurar la aceptación por parte de los actores relevantes.