Description du projet
Des traceurs biochimiques à la base du réseau trophique de l’Atlantique
Les activités humaines posent des problèmes majeurs pour les océans et affectent les processus des écosystèmes marins. Pour les résoudre, il est nécessaire de surveiller les océans à un niveau spatio‑temporel. Le projet ISOMOD, financé par l’UE, cartographiera les traceurs biogéochimiques à la base du réseau trophique afin d’établir les effets des facteurs de stress anthropologiques. Des données sur la composition isotopique stable seront étudiées et élaborées selon une innovante approche statistique spatiale afin de générer des «isopaysages» et de développer une image complète de la zone étudiée concernant trois mesures de base des processus des écosystèmes marins: la productivité, la structure du réseau trophique et les voies migratoires animales. Les résultats aideront à améliorer l’étude des changements alimentaires des macareux moines, ainsi que la prévision de la distribution du maquereau.
Objectif
The immensity of the oceans makes it difficult to monitor them at a spatio-temporal scale that is relevant for resolving ecological processes and responses to decades of pressure from multiple anthropological stressors. With IsoMod, I aim to map the biogeochemical tracers (stable isotope (SI) composition) at the base of the food web to inform three key measures of marine ecosystem processes that might be affected by these stressors: productivity, food web structure and animal migration pathways. The isoscapes will be developed at the scale of the North Atlantic Ocean and will be based on Calanus spp. carbon and nitrogen SI values, δ13C and δ15N. Lipid rich zooplankton organisms such as C. finmarchicus fuel a large part of the higher trophic level in the North Atlantic, including many species of fish, birds and mammals. I will use a recently developed spatial statistic approach where high resolution observational data (e.g. satellite data) are applied as predictors of SI variability, and apply these models to produce isoscapes with a full coverage of the study area. The application of these isoscapes will be showcased in two case studies. The first will test the role of changes in Atlantic puffin (Fratercula arctica) winter diet in key life-history parameters (e.g. body condition, survival rate). Specifically, the isoscapes will be used to provide the trophic baseline needed to investigate changes in puffin trophic position associated with changes in diet. The second case study will use prey SI to improve forecast of Northeast Atlantic mackerel (Scomber scombrus) summer distribution. Variation in SI values can be linked to variation in secondary productivity and this will be used to identify best foraging conditions for mackerel ahead of their migration to the summer feeding grounds. This information will be investigated as a driver of mackerel summer distribution and their recent shift in distribution.
Champ scientifique
- engineering and technologymechanical engineeringvehicle engineeringaerospace engineeringsatellite technology
- natural sciencesbiological sciencesbiochemistrybiomoleculeslipids
- medical and health scienceshealth sciencesnutrition
- natural sciencesbiological sciencesecologyecosystems
- natural sciencesbiological scienceszoologymammalogy
Mots‑clés
Programme(s)
Régime de financement
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinateur
9019 Tromso
Norvège