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Quantifying Environmental and Social Interactions for Tuna fisheries Management

Final Report Summary - QUAESITUM (Quantifying Environmental and Social Interactions for Tuna fisheries Management)

The general objective of the project QUAESITUM is quantifying the main components that drive the associative behavior of tropical tuna around floating objects, thus contributing at reducing the gap between research and tropical tuna purse-seine fisheries management. In particular, the project addresses the issue of understanding the spatial distribution and behavior of tropical tuna in a network of fish aggregating devices (FADs), which are largely employed by the tuna purse-seine fisheries worldwide.

The specific research objectives (RO) are:
➢ RO1. Providing novel methods for the analysis of passive acoustic data.
➢ RO2. Developing novel field-based models for fish dynamics in a network of FADs in the presence of social interactions and environmental heterogeneities.
➢ RO3. Characterizing the gregarious-fish behavior in the presence of spatial heterogeneities in a controlled environment.

The specific objectives detailed above contribute to the following general objectives:
➢ RO4. Contributing at a sustainable management of the tropical tuna purse-seine fisheries through the assessment of the impacts of FADs on tuna behavior.
➢ RO5. Improving our knowledge on the associative behavior of fish, through the identification of universal features and interactions common to different fish species.

The training objectives of the project are:
➢ TO1. Enlarging the Marie Curie fellow’s background on the analysis of ethological data
➢ TO2. Learning new approaches in ethological modeling.
➢ TO3. Becoming familiar with experiments in a controlled environment.
➢ TO4. Teaching students.

The main results and achievements of the project (PR) are the following:
➢ PR1. Achievement of new methods for the analysis of passive acoustic data (Capello et al., PONE, under review; Forget, Capello et al., Can. J. Fish., under review)
➢ PR2. Derivation of a new modeling approaches that describe the tuna associative dynamics (Capello et al., in prep)
➢ PR3. Creation of a dedicated infrastructure for performing experiments on fish behavior in a controlled environment at the USE Lab.
➢ PR4. Collection of novel experimental data on the associative behavior of zebrafish in a controlled environment (Bette, Capello et al., in prep.)
➢ PR5. Evaluation of the ghost fishing of silky sharks due to FAD fisheries (Filmalter, Capello et al., 2013)
➢ PR6. Application of the novel quantitative methods for the analysis of tropical tuna behavior on anchored FADs (Rodriguez-Tress, Capello et al, in prep) and drifting FADs (Govinden, Capello et al., in prep.).

The contribution of the above results towards the development of novel quantitative approaches for studying the associative behavior of fish lead to a significant impact of the QUAESITUM project on the scientific community that employs acoustic data and studies fish behavior. Secondly, the research facility that has been constructed for conducting the laboratory experiments on fish behavior significantly contributed to the creation of a new research line in the USE Lab. This facility will be employed in the frame of a PhD fellowship recently obtained at the lab (S. Bette, FNRS) and will guarantee the long-term preservation of this research line, as well as the intra-European collaborations pursued during the project. Moreover, the work conducted during the project lead to the derivation of a novel approach for estimating the abundance of tropical tuna, based on its associative behavior around FADs. This result has an important impact on the overall fisheries management community and opens the way toward new research lines, where alternative abundance indicators, based on fish behavior, can be obtained from field data.

Finally, the project had a remarkable impact on the fellow’s research path. The training activities conducted during the project improved the fellow’s skills and contributed to a twofold success: 1) The fellow successful passed a selection process and obtained a three-years research contract at IRD in Sète (France) 2) The fellow was awarded an ANR grant for her future research project on abundance estimate based on tuna behavior (ANR @RAction program, BLUEMED project, 2014-2019, 274k Euros).