FLOW MONITOR   

LakePulse: A National Portrait of Lake Health

Yannick Huot   |   February 2020

The NSERC Canadian Lake Pulse Network (“LakePulse”) is a large academic-government-NGO partnership on environmental issues affecting lakes. LakePulse assesses and forecasts the health of lakes across Canada related to watershed land use, climate change and a suite of measured lake characteristics. This large-scale assessment compares lake health in 13 ecozones across Canada to examine the impact of human stressors on lake functioning.

Over 3 summers, LakePulse conducted an unprecedented field campaign to sample about 665 lakes across Canada from Newfoundland to the Yukon. Over 100 variables were sampled at each lake using traditional approaches as well as state-of-the-art methods in the fields of genomics, emerging contaminants, greenhouse gases, pathogens, and paleolimnology. The field campaign together with historical archives and an analysis of over 80,000 lake watersheds are being used to examine how lakes have changed and how they may change in future.

Assessing “lake health” across Canada is critical to understanding ecosystem services and their vulnerability to human disturbances. In LakePulse, “health” is used to indicate a departure of the ecological state of a lake from the pristine state. Several research projects focus on reconstructing past changes (e.g., sediment cores) and studying the present health status of sampled lakes. Other projects extend these results to unsampled lakes and into the future through remote sensing, spatial modelling, and statistical analyses based on cause and effect relationships between water quality, watershed characteristics, and climate change.

Early results from LakePulse show strong human impacts on lake biota (e.g., bacteria, phytoplankton communities), greenhouse gas emissions, and the presence of pesticides and pharmaceuticals in lakes. Until now, the presence of pesticides and pharmaceuticals has been poorly quantified at large scales for Canadian lakes. Furthermore, paleolimnological analyses provide baseline data and are showing significant changes in lake communities over the last 200 years. Data obtained from the LakePulse genomics projects have allowed new insights into how human impacts in watersheds shape bacterial communities on landscape scales.

LakePulse projects are providing the science required to understand baseline environmental conditions, measure changes, understand relationships between stressors and responses, and predict environmental changes. By addressing such knowledge gaps about the impact of watershed-scale environmental changes on lake health, LakePulse hopes that the improved understanding of cause and effect, as well as trends, will inform policy in a broad range of matters, including water quality and chemicals management, climate change adaptation, improving agricultural practices, and the definition of guidelines and objectives.

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