EcoScope Determining energyscapes for Mediterranean marine megafauna

Dates: 2022–current

Research team: LIENSs UMR 7266 La Rochelle Université - CNRS; CEFE UMR 5175 CNRS-Université de Montpellier - Université Paul-Valéry Montpellier - EPHE.

Collaborators: Dr David Grémillet, Dr Nicolas Courbin

I join, in 2022, Dr David Grémillet within the framework of the EU-funded EcoScope project (“ecocentric management for sustainable fisheries and healthy ecosystems”, www.ecoscopium.eu), with the objective of determining energyscapes of marine megafauna throughout the year. Energyscapes represent variations in energetics needs of an organism through geographical space depending on occurring environmental conditions. With these estimated energyscapes, and building from knowledge of diet composition and body mass distributions in population, we will estimate the total biomass of foraged species consummed by the marine megafauna community within the Mediterranean Sea, in summer. This work is focused on a wide panel of species (cetaceans, seabirds, sea turtles, tunas, sharks, rays, swordfish) and will combine data of very different nature within a consistent statistical framework. After we obtain such estimates, we will compare it to estimates of fish stocks and fisheries catches in the basin.

Furthermore, to conduct this work, we need reliable maps of species abundance. For some species, such maps are still lacking or biased, such as for the Scopoli’s shearwater for which the observation data on which the current estimate relies are biased due to strong detection issues (hour effect). In the Mediterranean, the Scopoli’s shearwater is one of the most studied species by means of tracking technology. To overcome the detection issue with observation data, we will take full advantage of the tracking data and build a statistical framework to integrate both data types to estimate a reliable map of Scopoli’s shearwater abundance in the Mediterranean.