SES Seminar Guest Dr. Chris Parsons

University of Waterloo

Legacy phosphorus in freshwater sediments: Mechanisms controlling internal P loading and eutrophication

Legacy phosphorus in freshwater sediments: Mechanisms controlling internal P loading and eutrophication

Anthropogenic nutrient enrichment has led to the accumulation of phosphorus in many freshwater sediments. This legacy phosphorus may be either buried or remobilized to overlying water, contributing to the proliferation of harmful algal blooms, near shore algal fouling and bottom water anoxia. The chemical, physical and biological factors influencing the stability of phosphorus in the solid phase, and hence the release of phosphorus to overlying water are complex as well as temporally and spatially variable. I will present a study on phosphorus speciation in sediments of a coastal marsh of Lake Ontario, highlighting the coupled biogeochemical cycling of carbon, nitrogen, phosphorus, iron and sulfur and contrasting the impact of enzymatic and mineralogical controls on phosphorus mobilization. I will also review the importance of internal phosphorus loading across a range of Canadian freshwater environments.

Bio

Undergraduate and MSc: University of Manchester, UK (2003-2007) Supervisor: Jon Lloyd)

PhD (2011): Environmental Geochemistry (European Commission Marie-Curie research training network: AquaTRAIN). Supervisor: Laurent Charlet.

Split between:

European Commission Soils Action (Ispra, Italy)

University of Grenoble (France)

University of Girona (Catalunya/Spain)

Post-doc (2011-2012): French nuclear waste management organization (ANDRA).

Post-doc (2012-2015): University of Waterloo, Ecohydrology Research Group (Supervisor: Philippe Van Cappellen)

2015-2017: Research scientist, Ecohydrology Research Group. Contracted under MOECC

2017-current: Research assistant professor, Ecohydrology Research Group, Department of Earth Sciences, University of Waterloo.