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Oceanic tunas as indicators of ecosystem health

Final Report Summary - OCEANTUNEIN (Oceanic tunas as indicators of ecosystem health)

Understanding to what extent human activities have altered marine biodiversity is an increasingly urgent societal challenge and of considerable scientific and policy concern. Our ignorance of the pressures upon and fate of marine biodiversity is, in part, because there are few synoptic global indicators to measure changes in marine biodiversity – particularly for exploited organisms. The main objective of this project was (1) to develop new indicators for measuring biodiversity change in oceanic marine ecosystems for the Atlantic, Pacific and Indian Ocean, using tunas, billfishes and sharks as sentinels of ocean health and (2) to develop management guidelines to determine how these indicators can be effectively used for improving management and conservation of oceanic ecosystems.

This project has provided the tuna-focus Regional Fisheries Management Organizations (RFMOs) with a set of new products –a set of pressure, ecological state and threat indicators and a set of specific management guidelines, to assist them in the incorporation of ecosystem considerations in the management and conservation of tuna and tuna-like species. Task 1 “Compilation of state-of-the-art stock assessments and fishery database preparation” has resulted in a global dataset of stock assessment outputs for 50 stocks (18 species) of oceanic tunas, billfishes and sharks which has been pivotal for the development of the other tasks and potentially could support other research projects in the future. Task 3 “Revision of current state and progress of ecosystem considerations in the five tuna RFMOs” have resulted in a global review and report card on progress in the five tuna RFMOs implementing an ecosystem approach to fisheries management. Task 2 “Estimation of ecological state indicators –namely the Bayesian Red List Index” and Task 4 “Performance analysis of pressure and state indicators” have resulted in the creation of a Bayesian Global Red List Index of oceanic tunas, billfishes and shark, which tracks biodiversity change in the high seas within the last 50-60 years using highly migratory fish species as sentinels of ocean health. Task 6 “Estimation of pressure indicator-namely total fishing mortality rate on an ecosystem” and Task 7 “Estimation of ecological state indicators –namely total biomass trajectories” have resulted in the creation of two multispecies integrated biomass and fishing mortality indicators which potentially could be used by tuna RFMOs to diagnose the state on the fished and assessed part of the ecosystem in their convention areas. Task 5 “Development of management guidance of how to use ecosystem indicators to assist decision making” has resulted in a preliminary framework for an indicator-based report card which could potentially be further developed and used in the tuna RFMOs to better link ecosystem science into their fisheries management.

Accordingly, this project (1) has delivered new understanding of the global picture of the status of oceanic ecosystems using tunas and billfishes as sentinels of ocean health; (2) has provided new tools by developing a set of new pressure and ecological state indicators, and testing their performance to measure biodiversity change in order to infer health in oceanic ecosystems; (3) has provided new training to the Fellow Juan-Jorda in a range of quantitative methods and professional skills; (4) has provided the international fisheries community and the tuna RFMOs with a set of new products –a set of pressure, and ecological state indicators and a set of specific management guidelines, to assist in the management and conservation of tuna and tuna-like species; (5) has increased the capacity and active role of the EU in the development of new ecosystem approaches; (6) has fostered international collaborations between Canada through Simon Fraser University and Europe through AZTI Tecnalia in Spain; (7) is resulting in a series of high impact research articles in international journals which are currently either being peer-review or are under development; and finally (8) has raised societal awareness through effective communication of the benefits of healthy oceans for the well being of humanity. The new knowledge, tools, training, and collaborations generated in this project have the potential to influence and support international policy treaties such as the Convention on Biological Diversity Strategic Plan for Biodiversity and the associated 2020 Aichi targets, as well as, for transparent independent monitoring of the success of local and regional conservation and management efforts in marine ecosystems.

This is the personal website of the fellow with a description of the project and its main products: