Analysis of phytoplankton functional types in the Gulf of Lions from satellite data and study of their influence on spatio-temporal dynamics of small pelagic fish
Throughout the world, small pelagic fish stocks are known to fluctuate a lot. Yet, the mechanisms responsible for the important spatio-temporal variability in these stocks remain mostly unknown. Environment is often supposed to be the main driver of small pelagic dynamics, thus assuming a bottom-up control of their populations. This project aims at testing this hypothesis by evaluating the potential link between plankton and small pelagics in the North-West Mediterranean Sea (NWMS). The first step will be to assess the phytoplankton composition of the NWMS since 1997 using PhySat algorithm based on ocean colour satellite data. The study of its spatio-temporal distribution through geostatistics and wavelet analyses should yield important insights on potential changes or shifts in plankton community composition during the last 15 years. Then, the link between phytoplankton spatio-temporal distribution and abiotic conditions (such as temperature, meso-scale dynamics) will be investigated. The final step of this project will be to test the main hypothesis of a bottom-up control of small pelagic fish by comparing the phytoplankton production datasets and those of abundance, biomass and condition indices of small pelagics obtained since 1993.
Keywords: phytoplankton, remote sensing, functional type, bottom-up process, optic reflectance, Physat, environmental effects, spatial dynamics.
We are looking for a highly motivated candidate in possession of a PhD in marine biology, oceanography or fisheries science. Skills in scientific computation and modelisation are necessary, as well as in remote sensing data manipulation. A good knowledge of plankton would also be highly appreciated. Finally, a good level of English writing is expected.