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Adaptation of Freshwater Ecosystems to Agricultural Contaminants

Our results will improve our understanding of the effect of land-use on aquatic communities.


Principal investigators with McGill University: Graham Bell, Rowan Barrett, Melania Cristescu, Andy Gonzalez, Gregor Fussman, Andrew Hendry

What challenge does "Adaptation of Freshwater Ecosystems to Agricultural Contaminants" address?

With the industrialization and intensification of agriculture, the use of pesticides has risen dramatically around the globe, leading to current concerns over toxicological and health impacts. The most widespread pesticide is the herbicide glyphosate which now ranks first in both sales and treated surface area worldwide. Glyphosate-based herbicides are predominantly used in association with genetically-engineered resistant crops (GERC) and the extensive adoption of GERC has increased glyphosate application 15-fold, and their sole cultivation currently accounts for 56% of global glyphosate use. As such, the combination of the broad-spectrum nature of glyphosate, the introduction of GERC varieties, and intensive farming practices such as monocultures have elevated the class of glyphosate-based herbicides to no less than the single most applied agricultural chemical ever used by humans. Along with glyphosate, the neonicotinoid insecticides (the most widely-used family of insecticide) are also the focus of much concern over the toxicological effects on non-target organisms. We focus on imidacloprid, the most common neonicotinoid insecticide, which in Canada is used to coat seeds and protect saplings from herbivore damage. Imidacloprid is known to be toxic to stream insects but its impacts on lake plankton have not been studied. In fact, the impacts of both glyphosate and imidacloprid on lake food webs remain poorly understood, as toxicological studies have so far focused on the short-term impact of single contaminants on monocultures of laboratory model species that could be naturally resistant to stressful contaminants.

How will this research address the challenge?

We expose entire communities of naïve organisms to both single and combinations of pesticides, in high or low nutrient backgrounds by performing a long-term experiment that allows sufficient time for adaptation to stressors. Several terrestrial weed species and some freshwater algae can evolve glyphosate resistance under laboratory conditions, suggesting that evolutionary rescue is likely in response to this stressor. The possibility that organisms can evolve resistance to imidaclorid has never been tested.

What impact will the project have on agriculture?

Our proposed collaborations with University of Guelph will consolidate the planetary-scale mission of “transforming agriculture’s impact on biodiversity” that guides the Food from Thought program. Our main objectives are to 1) provide an improved understanding of the effects of land-use disturbances on aquatic communities, 2) develop genomic tools for accurate monitoring and real-time tracking of freshwater biodiversity and ecosystem health and 3) develop “engineered” communities of organisms.

Key messages

Our results will improve our understanding of the effect of land-use on aquatic communities. Canadian key industries will be able to extract resources from the environment in a sustainable manner. Our refined genomic tools based on environmental DNA and RNA will eliminating the costs for expert taxonomic knowledge and time-consuming sampling and will allow close monitoring of biodiversity trends. The “engineered” communities will allow ecosystem remediation to happen at a time when it is still feasible and affordable.

Other information

University of Guelph Businesses: WSP.

Postdoctoral fellows: Vincent Fugere and Jorge Negrín Dastis Graduate students: Marie-Pier Hebert; Naila Barbosa da Costa; Katie Millette; Michaela Harris Collaborators: Beatrix E Beisner; Jesse Sapiro.

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