Laboratoire des sciences aquatiques
Département des sciences fondamentales
Université du Québec à Chicoutimi
555, boulevard de l’Université, Local P3-1070
Chicoutimi (Québec) G7H 2B1
Canada
Courriel : grosbois.gui@gmail.com
Tel: 1-418- 545-5011 ext 2336

Research (Français)

Fish are the main source of essential fatty acids (FA) for many human populations in the world, and significantly so in the Inuit communities of the Arctic. Animals including humans must ingest essential FA (omega-3, omega-6) because the body requires them for good health, cannot synthesize them de novo, and must acquire them with diet. They are mostly synthesized by algae and then transferred and preserved in lipid reserves through the food web. Therefore, the accumulation and composition i.e. quality of FA in consumers is affected by changes in the algal FA production. Measures of algal, zooplankton and fish production rates are rare in the aquatic literature as they are challenging and time consuming, especially when carried out in remote Arctic lakes. However, knowing the algal production of FA is essential for understanding zooplankton and fish growth as the FA are essential for consumer development. My project is about FA health indicators for the aquatic food web of Arctic lakes near Cambridge Bay in Nunavut (Canada). I aim to identify the main sources of essential FA in lakes and to quantify their transfer along the food web up to fishes and ultimately to human consumption. Estimate present production rates and transfers from producers to consumers will permit to evaluate the effects of global warming on those ecosystems and to better predict the future of Arctic food webs.

Photos of the project “Ecosystem Health of Arctic Freshwaters”

Articles

Grosbois G. & Rautio M. (2018) Active and colorful life under lake ice. Ecology 99(3):752-754, DOI:10.1002/ecy.2074

Grosbois, G., Mariash, H., Schneider, T. & Rautio, M. (2017) Under-ice availability of phytoplankton lipids is key to freshwater zooplankton winter survival. Scientific Reports 7:11543, DOI: 10.1038/s41598-017-10956-0.

Grosbois, G., del Giorgio, P. A. & Rautio, M. (2017) Zooplankton allochthony is spatially heterogeneous in a boreal lake. Freshwater Biology, 62, 474-490, DOI: 10.1111/fwb.12879.

Schneider, T., Grosbois, G., Vincent, W. F. & Rautio, M. (2017) Saving for the future: Pre-winter uptake of algal lipids supports copepod egg production in spring. Freshwater Biology. 62, 1063-1072, DOI:10.1111/fwb.12925.

Schneider, T., Grosbois G., Vincent W.F. & Rautio M. (2016) Carotenoid accumulation in copepods is related to lipid metabolism and reproduction rather than to UV-protection. Limnology and Oceanography, 61, 1201-1213, DOI: 10.1002/lno.10283.

Piscart, C., Roussel, J. M., Dick, J. T. A., Grosbois, G. & P. Marmonier. (2011) Effects of coexistence on habitat use and trophic ecology of interacting native and invasive amphipods. Freshwater Biology 56:325-334, DOI: 10.1111/j.1365-2427.2010.02500.x.

Manuscrits

Grosbois, G., Vachon, D., del Giorgio, P. and Rautio, M. Terrestrial matter and phytoplankton contribute equally to zooplankton production in a boreal lake. Manuscript to be submitted.

Reports

Grosbois, G. (2009) Distribution and habitat characterization of two Mediterranean Gastropods in occidental Provence. Ms.S. thesis. 30p.(In French).

Grosbois, G. (2008) Horizontal and vertical distribution of invertebrate communities from the hyporheic zone of a Mediterranean river. Master 1 degree thesis. 18p. (In French).

Grosbois, G. (2007) Spatial and trophic competition between invasive and endemic Amphipods in Brittany. Master 1 degree thesis. 23p. (In French).

Conferences

Grosbois, G., Ayala Borda, P., Power, M., Culp, J. M., Lovejoy, C. & Rautio, M. How productive are lakes and ponds in the Kitikmeot Region? A first estimation of primary, bacterial and zooplankton production of Greiner Lake watershed. ArcticNet Annual Science Meeting, Dec. 2018, Ottawa, Canada. Oral presentation.

Grosbois, G., Power, M. & Rautio, M. Understanding Arctic Food Webs: a quantification of essential fatty acid sources, stocks and fluxes from plankton to fish. 27^th GRIL symposium, Mar. 2018, Orford, Canada. Poster

Grosbois, G., Power, M. & Rautio, M. Understanding food webs in Arctic lakes: Production and transfer of essential fatty acids from plankton to fish. Arctic Change, Dec. 2017, Quebec, Canada. Oral presentation.

Grosbois, G., Vachon, D., del Giorgio, P. & Rautio, M. Zooplankton production and allochthony follow different seasonal patterns in a boreal lake. SIL XXXIII Congress, Aug. 2016, Torino, Italy. Oral presentation.

Rautio, M. Grosbois, G., Mariash, H., Schneider, T. The underestimated role of autumn for zooplankton seasonal resource use and reproduction, as indicated by stable isotope, fatty acid and pigment analyses. SIL XXXIII Congress, Aug. 2016, Torino, Italy. Oral presentation.

Grosbois G., del Giorgio, P. & Rautio, M. Tributaries and macrophytes influence the spatial variability of zooplankton allochthony within a boreal lake. 25^th GRIL symposium, Mar. 2015, Saint Hippolyte, Canada. Oral presentation.

Grosbois, G., del Giorgio, P. & Rautio, M. River and macrophyte effect on aquatic food sources and their integration in zooplankton in a boreal lake. Joint Aquatic Science Meeting, May 2014, Portland, USA. Oral presentation.

Grosbois, G., del Giorgio, P. & Rautio, M. River and Macrophyte influence on food source integration in zooplankton in a boreal lake. 24^th GRIL symposium, Feb. 2014, Saint Hippolyte, Canada, Poster. Awarded as best PhD Poster

Grosbois, G. & Rautio, M. Seasonal pattern of seston and zooplankton isotope signatures. 23^rd GRIL symposium, Mar. 2013, Saint Hippolyte, Canada, Oral presentation.

Grosbois, G., Sastri, A. & Rautio, M. Zooplankton productivity dependency on terrestrial subsidies in boreal lake. ASLO Aquatic Sciences meeting, Jul. 2012, Otsu, Japan. Poster.

Grosbois, G., del Giorgio, P. & Rautio, M. Seasonal pattern of the integration of allochthonous carbon in boreal aquatic food web. 22^nd GRIL symposium, Mar. 2012, Saint Ferdinand, Canada. Poster.

Piscart, C., Grosbois, G., Rousselet, J-M & Marmonier, P. Biogéographie et micro-répartition des amphipodes de Bretagne : conséquence sur les réseaux trophiques associés à l’espèce endémique Gammarus duebeni celticus. 50^th AFL congress (French association of limnology), Nov. 2007. Toulouse, France. Poster.