SELECTED PROJECTS

PROJET 1 : GREEN EDGE

Biological productivity in the Arctic Ocean: past, present and future response to climate variations, and impacts on carbon fluxes, the marine food web and local human communities

Researcher responsable:

Marcel BABIN, UMI Takuvik

Assoxiated teams:

Laboratoire d'Océanographie de Villefranche (LOV)
Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff (SBR)
Laboratoire d'Océanographie MICrobienne (LOMIC)
Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN)
Laboratoire des sciences de l’Environnement Marin (LEMAR)
LIttoral ENvironnement et Sociétés (LIENs)
Institut Méditérranéen d’Océanographie (MIO)
Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC)
Biologie des Organismes Aquatiques et Ecosystèmes (BOREA)
Laboratoire d’Optique Atmospherique (LOA)
Laboratoire de Glaciologie et Géophysique de l’Environnement (LGGE)
INALCO – Institut national des langues et civilisations orientales
Sorbonne-Universités - Laboratoire Espaces, Nature et Culture (ENeC)
Greenland Climate Research Centre (Nuuk)Greenland Climate Research Centre (Nuuk)
Institut des Sciences de la Mer (ISMER, Rimouski)
Centre de recherche du CHU de Québec
Département de biologie, chimie et géographie (UQAR, Rimouski)
Centre de recherche en géochimie et géodynamique (GEOTOP, Université de Montréal)
University of Manitoba, Arctic Biogeochemical Laboratory (Winnipeg, MB)
University of Calgary, Department of Geography (Calgary, AB)
Canadian Museum of Nature

Chantier arctique

Credit photo : Pierre Coupel, Takuvik

SUMMARY:

Climate change has triggered fundamental modifications of marine biotopes in the Arctic Ocean (AO). The decrease in the extent of the ice pack during summer has led to a 20% increase in pan-Arctic primary production (PP) over the last decade. Phytoplankton blooms now occur earlier in several parts of the AO. In other parts, some species found in warmer waters now migrate into the Arctic Ocean. Phytoplankton grow in the top tens of meters of both ice-free and ice-covered waters. The phytoplankton spring bloom (PSB) that develops around the ice-edge in the AO is generally associated with both large energy transfer to higher trophic levels and export of carbon to the bottom. In turn, the culture, health and economic capacity building of Northerners are closely associated with marine resources supported by the PSB. The Arctic PSB develops in the seasonally-covered ice zone (SIZ), the extent of which is expected to increase significantly during the next years, possibly over the whole AO as early as in 2030. The general objective of this research project is to understand the dynamics of the PSB and determine its role in the Arctic Ocean of tomorrow, including for human populations. More specifically, we want to 1) understand the key physical, chemical and biological processes governing/which governed the PSB, 2) identify the key phytoplankton species involved in the PSB and model their growth under various environmental conditions, and 3) predict the fate of the PSB and related carbon transfer through the food web and toward the bottom sediments over the next decades. First, a PSB event will be intensively studied during 2016 in the Baffin Bay from its onset under melting sea ice in May to its conclusion within the SIZ in July. Second, key phytoplankton species will be isolated and grown in the laboratory under various conditions to model their response to environmental factors and to understand their succession during spring. Third, a coupled physical-biological model will be optimized for simulating the PSB in the Arctic Ocean and for predicting changes in phyto-plankton communities and food web dynamics. In parallel, past and present trends in the intensity and spatial distribution of the PSB will be documented using a paleoceanographic approach, and using remote sensing. Finally, interviews and bilateral discussion with local Inuit communities will enable the documentation of changing marine productivity from a social perspective and feed into a multi-scale integrated analysis of environment-human interactions.

SCIENTIFIC OBJECTIVES:

The overarching goal of Green Edge is to understand the processes that control the phytoplankton spring bloom in the Arctic ocean as it expands northward, and to determine its fate in the ecosystem by investigating its related carbon fluxes. The questions we want to address in this project are, from the most specific to most general ones:
1. What is the exact sequence of events that control the onset, maintenance and end of the PSB around the ice edge, under the ice-pack and in adjacent open waters?
2. How do physical and chemical properties vary in space and time, and what are the processes responsible for those variations?
3. What are the key phytoplankton groups and species involved, and what do control their succession?
4. How much of the organic carbon produced by the PSB is transferred through the food web and toward the bottom sediments, and following which pathways?
5. What is the exact role of the Arctic Ocean PSB in the ecosystem functioning, over an annual cycle?
6. Will pan-Arctic marine primary production increase or decrease during the coming decades?
7. What will be the impacts of a different primary production on carbon fluxes at the air-ocean interface?
8. What will be the impacts of a different primary production for Northern communities?