David Walsh, PhD
Associate Professor and Canada Research Chair in Microbial Ecology and Genomics, Biology
Aquatic Microbial Ecology and Evolution
Microorganisms are a diverse component of aquatic ecosystems and their metabolic activities are central to energy, carbon, and nutrient cycling. Our research investigates the biodiversity, metabolic versatility, and evolution of these important aquatic microbes using novel genomics-based molecular approaches. Aquatic ecosystems under investigation include northern oceans, estuaries, and seasonally ice-covered northern lakes. All these ecosystems are impacted by climate change and other anthropogenic perturbations to varying degrees. Our research is coordinated to provide insights into how microbial distributions and activities may be influenced by these environmental pressures, and how changes in microbial distributions and activities may affect aquatic ecosystems as a whole.
Keywords: Microbial ecology and evolution, aquatic microbiology, genomics, metagenomics, Arctic Ocean
Tran P, Ramachandran A, Khawesik O, Beisner BE, Rautio M, Huot Y, Walsh DA. Microbial life under ice: metagenome diversity and in situ activity of Verrucomicrobia in seasonally ice-covered lakes. Environmental Microbiology (in revision).
Colatriano D, Tran P, Guégeun C, Williams WJ, Lovejoy C, Walsh DA. Genomic evidence for the degradation of terrestrial organic matter by Arctic Ocean Chloroflexi bacteria. Nature Communications Biology (accepted)
Ramachandran A and Walsh DA. (2015) Investigation of XoxF methanol dehydrogenases reveals new methylotrophic bacteria in pelagic marine and freshwater ecosystems. FEMS Microbiol Ecology.
Colatriano D, Ramachandran A, Yergeau E, Maranger R, Gélinas Y, Walsh DA. (2015) Metaproteomics of aquatic microbial communities in a deep and stratified estuary. Proteomics. 3566-79.
Walsh DA. (2014) Consequences of climate change on microbial life in the ocean. Microbiology Today.
El-Swais H, Dunn KA, Bielawski JP, Li WKW, Walsh DA. (2014) Seasonal assemblages and short-lived blooms in coastal north-west Atlantic Ocean bacterioplankton. Environ Microbiol.
Georges AA, El-Swais H, Craig SE, Li WKW, Walsh DA. (2014) Metaproteomic analysis of a winter to spring succession in coastal Northwest Atlantic Ocean microbial plankton. ISME J. 8: 1301-13
Walsh DA, Lafontaine J, Grossart HP. (2013) On the eco-evolutionary relationships of fresh and saltwater bacteria and the role of lateral gene transfer in their evolution. In Lateral Gene Transfer in Evolution, U. Gophna (Ed). 55-77.