McGill University
Ph.D. candidate
Supervisor: Anthony Ricciardi
Irene Gregory-Eaves
Start: 2017-01-03
End: 2023-04-30

Project

The fate of microplastics in aquatic food webs
Microplastics—plastic particles of ≤5mm in size—are increasingly found to ubiquitously contaminate aquatic environments and diverse organisms. The concentrations of these chemically complex particles are ecologically significant parameters because of their environmental persistence and interactions with key ecological processes. Here, I propose that an essential step toward informing policy for managing plastic waste is to quantify the presence of microplastics both spatially and temporally by incorporating their sampling into standardized limnological protocols. I also propose that our understanding of the mechanisms regulating the cycling of these particles within freshwater food webs can be advanced using a community-level approach, which I demonstrate using a food web module in a series of laboratory experiments. These experiments showed that microplastic uptake occurs through different routes of exposure (particles in suspension, particles in surficial sediments, and those transferred via interspecies interactions), but is regulated by the life history traits of the organisms and their ability to retain these particles. The contamination load of each organism is affected by the concentration and route of exposure, as well as their biotic interactions. I applied a network approach in designing experiments with realistic environmental conditions, whereby I compared the sensitivity of different food web components to acquiring microplastics from various routes of contamination. Finally, my work has shown that, under current and projected warming as well as microplastic contamination scenarios, these co-occurring stressors negatively impact the predatory performance of an invasive benthic predator, the round goby, and thus have potential repercussions on the structure and function of freshwater food webs.

Keywords

microplastique, réseau trophique, Saint-Laurent

Publications

1- Otolith elemental fingerprints distinguish Atlantic cod spawning areas in Newfoundland and Labrador
D’Avignon, Geneviève, George A. Rose
2013 Fisheries Research

2- Microplastics in lakes and rivers: an issue of emerging significance to limnology
D’Avignon, Genevieve, Irene Gregory-Eaves, Anthony Ricciardi
2022 Environmental Reviews

3- Feeding behavior and species interactions increase the bioavailability of microplastics to benthic food webs
D’Avignon, Geneviève, Sophia S.H. Hsu, Irene Gregory-Eaves, Anthony Ricciardi
2023 Science of The Total Environment

4- Effects of elevated temperature and microplastic exposure on growth and predatory performance of a freshwater fish
D'Avignon, Geneviève, Duncan Wang, Heather B. Reid, Irene Gregory‐Eaves, Anthony Ricciardi
2023 Limnology and Oceanography