Storm Alex, development of a land and underwater GIS of the Roya Valley for a multidisciplinary study of risks of natural origin

At the beginning of October 2020, the storm Alex caused enormous human, material and economic damages in the coastal valleys of the Alpes-Maritimes, in particular the Roya valley.  
The elements carried by the river were deposited in an underwater delta off Ventimiglia. The sediments of this delta will be studied (in other scientific projects) in order to reconstruct the history of this type of hydrometeorological event. 
The proposed M2 subject consists in the elaboration of a Geographic Information System to model the links between the hydrosedimentary processes of the Roya basin and the submarine deposits, by integrating multidisciplinary data (in SHS and geosciences) as well as different spatial scales (from the river bed to the catchment area) and temporal scales (from the recent event to those of the last 10,000 years, which should be identified in the delta) 

Hosting structure: Mediations - Sciences of places, sciences of links of Sorbonne University in cooperation with the University of Côte d'Azur (UMR Geoazur).  

ALEX storm, cross-referencing hydro-climatic and sedimentary signatures recorded on land and at sea during floods on the Côte d'Azur
 

The dramatic consequences of storm Alex in the Alpes-Maritimes in October 2020 reminded us of the great vulnerability of territories subject to Mediterranean episodes. In a context of changing climate, understanding the evolution of the frequency and intensity of such extreme hydrometeorological events is a major scientific challenge. The objective of this internship is to cross-reference, for the Côte d'Azur region, the reconstructions of high floods observed on land during the last 150 years with sedimentary records at sea, in order to better understand the mechanisms generating these episodes, and then to identify their record in marine sedimentary archives.

Host structure: Environmental Media, Transfers and Interactions in Hydrosystems and Soils of Sorbonne University in cooperation with the University of Côte d'Azur (UMR Geoazur).

ALEX storm, sedimentary record of an extreme hydro-meteorological event off Liguria
 

Sedimentary archives allow recording the recurrence of exceptional events (such as earthquakes or catastrophic climatic events) on land and at sea. Following the passage of the ALEX storm that affected the Maritime Alps and Liguria on October 02-03, 2020, large quantities of sedimentary materials were discharged into the sea. We propose to study the consequences of submarine flows that must have been generated in the Var and Roya submarine canyons during the storm. The analysis of sediment cores and seabed geomorphology will allow us to understand the submarine sedimentary processes associated with such extreme events and should allow us to evaluate their recurrence over time.

Hosting structure: ISTeP, Institute of Earth Sciences of Paris of Sorbonne University in cooperation with the University of Côte d'Azur (UMR Géoazur).

Biogeographic study of a declining species: modelling the ecological niche of the Northern Fulmar and comparing it to four decades of observations.

European populations of Northern Fulmar have collapsed by more than 40% since the mid-1980s. The causes and ecological consequences are poorly understood. The hypotheses proposed - warming temperatures, decrease in prey abundance, impact of fisheries discards - have only been put forward from specific studies conducted over short periods of time. They underline the complexity of the mechanisms involved. Prioritizing the factors - and their interactions - at different spatial and temporal scales that cause variations in these populations is an essential prerequisite for understanding the ecological consequences of a decline on a European scale.

Hosting structure: Laboratory of biology of aquatic organisms and ecosystems of the Muséum National d'Histoire Naturelle and Sorbonne University in cooperation with the FAMRI "Faroese Marine Research Institute" laboratory

Study of the evolution of the dynamics of planktonic ecosystems in an ultra-oligotrophic area (Levantine basin in the eastern Mediterranean) in a context of climate change.

The Mediterranean is one of the most sensitive regions to climate change. In order to characterize the formation and dispersion phenomena of the Intermediate Levantine Water (key water mass for the general circulation in the Mediterranean) and their biogeochemical consequences, the PERLE program includes 5 campaigns at sea between 2018 and 2021. The aim is to sample, analyze and interpret biogeochemical data (nutrients, organic matter) collected in connection with physical and modeling approaches.

Host structure: Microbial Oceanography Laboratory of Sorbonne University in cooperation with CEFREM, training and research center of the University of Perpignan.

Understand the metabolic production of the algal epimicrobiota by a combined approach of metabolomics, fluorescence in situ imaging (FISH) and mass spectrometry imaging,
 

The large brown algae, Phaeophycae, form very productive underwater forests that play a major role in the biodiversity of marine ecosystems. However, they are threatened by the global changes affecting the oceans. The microorganisms they host, the algal microbiota, influence their health status and are the seats of microbial interactions governed by chemical mediators that are still poorly characterized. The use of metabolomics and mass spectrography will allow to characterize and map in situ the metabolome on the surface of the brown algae. Fluorescence imaging will allow to identify the different bacterial taxa present on the surface of the algae and to correlate the microorganisms with the identified metabolic production

Hosting structure: UMR Molecules of communication and adaptation of microorganisms of the Muséum National d'Histoire Naturelle in cooperation with the Institut de Systématique, Evolution Biodiversité of the Muséum and Sorbonne University

Analysis of the influence of temperature on the diversification dynamics of corallines (calcified red algae)
 

Due to their wide geographical and ecological distribution, their high specific diversity and their potential sensitivity (due to the presence of calcite impregnating their walls) coralline red algae are organisms that should be impacted by warming and acidification of the ocean. This taxon taken as a whole will allow us to evaluate the responses to these changes at different taxonomic scales. From georeferenced specimen sequences, the trainee will evaluate whether there is a link between the diversification rate and certain environmental parameters (temperature) or morphological and physiological traits such as wall composition.

Hosting structure: Institute of Systematics, Evolution and Biodiversity of the Museum and Sorbonne University in cooperation with the University of Bergen