Fine scale reconstruction of three-dimensional ecological landscapes in the ocean through the analysis of elephant seal track data
Technological advances in recent years have made it possible to equip elephant seals from the Kerguelen colony and the Valdes Peninsula (Argentina) with various sensors that can simultaneously sample the environment and the activity of the individuals at very high frequency. During their journey at sea, these pinnipeds thus record physical, biogeochemical and biological oceanographic variables. These measurements reveal the heterogeneity of the biological landscapes visited and make it possible to quantify the influence of oceanographic conditions on the spatial structuring of the animals and their prey.
Within this framework, this thesis project is built on three axes:
– Studying the influence of physical processes on the density and vertical distribution of biological fields.
– Reconstructing three-dimensional ecological landscapes in relation to oceanographic dynamics.
– Studying the spatial and temporal dynamics of water masses in order to better understand the spatio-temporal relationships between primary production and the distribution of individuals in intermediate trophic levels.
This project proposes to combine 2D spatial data from daily satellite observation maps with in situ data recorded by elephant seals. Functional data analysis methods will be associated with Lagrangian water mass monitoring methods in order to associate the ecological and biological structures of the water column with surface oceanographic characteristics by integrating several scales. This is a multidisciplinary approach combining physical oceanography, biological oceanography and behavioural analysis.
Thesis by Nadège Fonvieille (2020-2023)
Supervisors : David Nerini (MIO, Marseille) and Christophe Guinet (CEBC)