Joanna Gauthier

Many microscopic eukaryotic organisms, mostly protists, living in lakes are not fully described, and their importance in aquatic food webs is still poorly understood. For these reasons, I am interested in elucidating how protist communities (including diatoms) can be modified over a centennial time scale and how climate change and human impacts can influence these changes. My research work focuses mostly on lakes used by sockeye salmon as spawning areas, where I reconstruct past communities of small eukaryotes as well as populations of sockeye salmon using molecular methods applied to environmental DNA (eDNA) preserved in lake sediments.

With recent technological advances, molecular techniques applied to eDNA in aquatic environments are a valuable tool to help us understand the biodiversity surrounding us. As these methods are gaining in popularity in different fields of aquatic ecology, another goal of my research it to understand the advantages and the limitations of using molecular methods to detect organisms in paleolimnology. As diatoms are well preserved in lake sediments and widely used in paleolimnology, this taxon is an ideal candidate to evaluate the congruence of molecular and morphological identification in lake sediments.