Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

This thesis is structured in 3 chapters, the 1st chapter explores the link between crustacean zooplankton biomass from terrestrial origin (i.e. allochthony) using stable isotopes and the production of crustacean zooplankton community. This chapter is the result of a collaborative work between my supervisor Dr. Milla Rautio, my co-supervisor Dr. Paul del Giorgio, his PhD student Dr. Dominic Vachon and I. DV provided the gross primary production and river flow data. I carried out the sampling, data and statistical analysis as well as zooplankton identification and production calculations. I wrote the article together with MR while DV revised the final version. PdG will provide comments before submitting the paper to a journal. The second chapter uses fatty acid analyses, a complementary method to stable isotopes to study lipid reserves of the same zooplankton community. It allows a better understanding of how life history strategies influence the building of lipid reserves and how different food sources (phytoplankton, terrestrial organic matter, bacteria) are used in zooplankton life cycle and winter survival. This study has been possible thanks to the collaborative effort of Dr. M. Rautio and her post-doc fellow Dr. Heather Mariash who carried out the survival experiment, as well as MR’s PhD student Dr. Tobias Schneider who provided some of the seston fatty acid data. I designed the study with my supervisor’s help, carried out the sampling, lab work, data and statistical analysis. I wrote the manuscript with MR. All authors participated to the manuscript revision that is now submitted to Scientific Reports (February 2017). The third chapter looked at the spatial distribution of the allochthony in the most abundant copepod, Leptodiaptomus minutus in Lake Simoncouche and explained it ecologically with the carbon source distribution. This chapter has been published in Freshwater Biology (March 2017) thanks to the collaboration of Dr. M Rautio, Dr. P. del Giorgio and I. I designed the study, carried out the sampling, data, lab work and statistical analysis. I wrote this manuscript together with MR and PdG.