77th webinar in the CentrEau Hebd'Eau series entitled "A social ecological geography of southern Canadian lakes" by Roxane Maranger
Roxane Maranger is a Full Professor in the Département des sciences biologiques de l’Université de Montréal, a Canada Research Chair, Tier 1 in Aquatic Ecosystem Science and Sustainability, and a Visiting Professor at Uppsala University in the Department of Ecology and Genetics. She was President of the Association of the Sciences of Limnology and Oceanography (ASLO, 2022-2024), an international scientific society with over 3500 members from over 65 different countries and has held many other leadership positions in science, and is the 2024 winner of the Rigler Award from the Society of Canadian Aquatic Science from her contributions in limnology. Her research is broadly related to how anthropogenic activities on the landscape and climate change influence water quality, greenhouse gas emissions, and major biogeochemical cycles in both freshwater and marine ecosystems.
Abstract:
Canadians love to swim, fish, and navigate in and on the countless lakes across the country. But Canadian lakes are under a considerable amount of pressure from human activities in their watershed. The expansion of cities, intensive farming, wetland loss, and industrial development all result in the transfer of pollutants to aquatic habitats, threatening the health of lakes and the ecosystem services they provide. Where are lakes being used across Canada? What condition are they in and is their use under threat from different pressures? To answer these questions, we combined information from many different sources, including a national scale lake assessment, through the NSERC Strategic Network Cluster Lake Pulse to create the first social-ecological geography of southern Canadian lakes. Regionally specific reference conditions were established from lakes considered healthy due to limited human activities in their watershed. When lakes with impacted watershed were compared to healthy ones within their specific region, two early warning signals of human pressure, pollution from nitrogen found in fertilizers and sewage, and chloride found in road salt, determined whether a lake was altered. We combined these two health indicators with information on future potential lake threats, and use by the population for recreational purposes. Using a colour-coded mapping technique, we were able to identify regions where lakes were altered, threatened, and used. These regions occurred primarily around dense urban areas, of southern Ontario and Quebec, and major cities on the east and west coast. Lakes were altered and threatened, but seemingly less used in the Prairie Provinces. The novel approach is very adaptable, easy to understand, and can be used at more regional levels for management to determine priority sites for conservation and restoration, as well as in science communication to describe overall lake health.
The presentation will be in French
