RESEARCH THEMES
THEME 1 – Oceanic circulation and numerical simulations
1.1 Freshwater impact on estuarine circulation
In the St. Lawrence and the Arctic, circulation is calculated on very fine scales and considers the freshwater flows in order to understand the mixing of the water masses and the biogeochemical components. Numerical simulations will be developed to produce a 3D hydrodynamic model applicable to climatic scenarios and ecosystems models
1.2 Regional model of circulation in the Arctic
Ice pack reduction and water warming are documented for the Arctic Ocean with the long-term correlation between mooring data and satellite data. These detailed observations will feed high-resolution models able to predict variations and trends of the Arctic ice conditions, and to be coupled with ecosystem models
THEME 2 – Coastal and oceanic geodynamics
2.1 Coastal geodynamics of the St. Lawrence
Sedimentary dynamic is studied in the St. Lawrence coastal marshes and bordering intertidal areas to deepen the knowledge on mechanisms responsible for bank erosion and littoral morphology changes. Projects will specially address sedimentary transportation by ice processes and interactions between hydrodynamism, vegetation, benthic fauna and sedimentary transportation.
2.2 Natural risks in coastal and underwater areas
Catastrophic events such as earthquakes and underwater slips (natural risks) threaten marine and coastal ecosystems, including permanent engineering structures at the bottom of the water or along coasts, and bordering communities. The various phenomena and the characterization of their signatures are analyzed for a better management of these natural risks, by predicting their potential impacts and by proposing attenuation methods of their impacts.
THEME 3 – Biogeochemical cycles
3.1 Oceanic component of the global cycle of carbon
Oceanic carbon flows (dissolved and particulate) are studied in the St. Lawrence and the Canadian Arctic, combining lab work and sampling, teledetection and modeling. The team will link carbon fluxes and the main physical, photochemical and biological processes which will contribute to clarify the relationships between oceans productivity, atmospheric CO2 concentrations and climate.
3.2 Ocean-atmosphere exchanges
Mechanisms responsible for the marine production of gases in trace, dimethylsulphide (DMS) and nitrous oxide (N2O), are studied according to their impacts on climate (formation of aerosols, greenhouse gases). The importance of the wind contribution in iron in the oceanic biogeochemical cycles is also evaluated. Biophysical models of the production of these gases will be developed from samplings in the North Pacific, the North Atlantic, and the Canadian Arctic.
3.3 Eutrophication of the coastal marshes and nitrogen cycle
The subarctic littoral is currently subjected to an increase of anthropogenic nitrogen and of changes in sea level. The team will seek to link the nitrogen cycle of marshes and tributaries to the hydrological, geochemical and ecological data of the St. Lawrence Estuary. The role of nitrifying and denitrifying communities on the nitrogen cycle in the subarctic marshes will thus be better understood.
3.4 Hypoxia in the estuary and the Gulf of the St. Lawrence
Following the underscoring of abnormally weak concentrations of oxygen in the deep waters of the St. Lawrence, the team will develop quantitative tools predicting the changes of oxygen levels in the St. Lawrence, and their impacts on ecosystems and marine resources.
THEME 4 – Function and integrity of the Arctic and subarctic marine ecosystems
4.1 Ecological and evolutionary impacts of the climatic changes in the St. Lawrence
The various communities (pelagic, benthic, birds, mammals) settled in the heterogeneous coastal zones or in offshore waters will be studied according to ecological and evolutionary approaches. The behaviors, physiology, productivity, dynamics and structure of the populations and their connectivity, trophic webs and their stability, functional genomics, biodiversity, biological invasions will be the indicators used to estimate the communities’ responses to climatic change.
4.2 Impact of the ice cover reduction on the Arctic ecosystem
The team aims to determine the space-time link between the ice cover and the seasonal primary production, which in turn controls the ecosystems’ maturity at the end of the biological production season. The data will be collected via missions at sea, a network of long-term autonomous observatories (moorings), and sea observations by satellite. This study is the most exhaustive until now in the Arctic, covering hydrodynamics and the whole pelagic ecosystem (virus, bacteria, phytoplankton, zooplankton, fish and mammals).
4.3 Aires marines Protected marine areas, bioconservation and genomics
The local structuring and large-scale dispersion of the communities are examined using the complex system theory, biogeography, genetics of the landscape, isotopic analysis, teledetection and marine acoustics. Results will make it possible to propose or improve regulations concerning protected marine areas and the bioconservation of species threatened by the tourism industry, navigation or stocks exploitation.
THEME 5 – Biotoxins, contaminants and human health
5.1 Marine biotoxins
Since climatic changes are probably affecting toxic algae blooms (Alexandrium tamarense and Pseudonitzschia spp.) in the St. Lawrence estuary, the team is developing biophysical models to identify the key factors responsible for blooms in order to ultimately predict them. Research also relates to clinical and epidemiologic aspects of toxinic intoxications, occurring as well in the St. Lawrence as in the Pacific Ocean (ciguatera)
5.2 Transfer of contaminants in the food chain
In the St. Lawrence, research relates to the transfer of the anthropogenic contaminants of sediments, particles and the water column towards higher trophic levels (invertebrates, fish, pinnipeds and cetacea). A management model of contaminants in the St. Lawrence will be developed in collaboration with the Saguenay-St. Lawrence Marine Park. In the Arctic, mechanisms and levels of contamination of pinnipeds and cetacean (under controlled hunting) will be examined for a better management of these species’ stocks.
5.3 Oceans and human nutrition
The polyunsaturated fatty acids from marine origin (omega-3) are studied from a biological point of view (transfer and metabolism of the omega-3 in the food chain, space and temporal variations) and from a human health point of view (protection role against chronic diseases). These projects will make it possible to estimate the impact of dietary changes caused by climate change on the health of Canadian High Arctic Aboriginal people.
