Graduate Students

GENEVIEVE D'AVIGNON
The fate of microplastics in fluvial food webs.

For my PhD research, I am using a network approach to evaluate the ecological risks associated with microplastic contamination of the Great Lakes-St. Lawrence River system. To keep this research ecologically and socially relevant, I am using microplastics concentrations reported from environmental samples from the St. Lawrence River to design experiments to generate detailed knowledge of their bioavailability to wildlife, their pathway of entry and fate in food webs, and their impacts on aquatic communities. More specifically, I am using a community module of three highly interacting species: dreissenid mussels, gammarid amphipods and round gobies to understand the role of environmental abundance, vector pathways and species interactions - including trophic (predator-prey) and behavioural (mutualistic, commensalistic) interactions - on microplastic contamination within aquatic food webs.

SUNCI AVLIJAS
Spatio-temporal variation in the colonization success and impacts of globally invasive freshwater fishes.

My PhD research investigates patterns of colonization and impact of invasive freshwater fishes. My model species include the Round Goby and the Tench (Tinca tinca). The latter is a Eurasian species that has been introduced globally. I am taking a large-scale approach to understanding context-dependent variation across local, regional and biogeographic scales, using a combination of field surveys, functional response experiments and morphometric (shape space) analysis. My field work is currently being conducted in various areas of North American and South Africa.

KENNEDY ZWARYCH
Longterm changes to native freshwater mussel populations in the St Lawrence River.

With collaborators from Environment Canada, I am compiling historical data from the last thirty years to characterize changes in native freshwater mussel (unionid) populations. My MSc research will create a resource that allows for other biologists to test their own hypotheses relating to this data set. Retrospectively, we have good knowledge of when recent invaders became established in the St. Lawrence River and how much the climate has warmed, so it is possible to investigate changes to invertebrate communities in the river before and after these events.

MEGAN HUTCHINGS
Comparative functional responses of native and non-native benthic fishes under elevated temperatures.

For my MSc research, I will be using predictive methods to determine the potential impacts of emerging and existing aquatic invasive species in the St. Lawrence River: the Tubenose goby (Proterorhinus semilunaris) and the Round goby (Neogobius melanostomus). Furthermore, I will examine how climate change will affect the future invasion success of both species, using a comparative functional response approach to quantify prey consumption as a function of prey density. This will allow interpretation of the per capita effects of these invaders towards native prey species. In parallel, I will examine both species’ capacity to perform and survive in increasing water temperatures by measuring Critical Thermal maximum (CTmax).

NOÉMIE SHEPPARD
Predicting context-dependent impacts of invasive crayfishes.

I am primarily interested in the relationship between environmental context and the invasion success. My MSc research predicts how increased surface water temperatures, following climate change, may modify the impacts of invasive crayfish in the Great Lakes. Focusing on two invasive crayfish from aquaria, namely the red swamp (Procambarus clarkii) and marbled crayfish (Procambarus virginalis), my work examines the effect of temperature on resource consumption and competition. Following previous work in the lab, resource consumption will be modelled using comparative functional responses, and resource competition will be modelled with various agonistic interaction experiments. The aim of this research is to better inform policy surrounding the importation of potentially invasive crayfishes into Canada.

TY COLVIN
Temporal changes in biodiversity of St. Lawrence River benthic invertebrate communities.

For my Ph.D. research, I am investigating patterns of benthic invertebrate biodiversity change in the St. Lawrence River over the past 40 years and relating spatiotemporal changes in benthic communities to different species invasions and climate warming thresholds. To this end, I am comparing modern benthic communities along the river to long-term historical community data and relating biodiversity change to the establishment and spread of specific invasive species. I am also conducting field experiments to test hypotheses on the role of different invaders in influencing benthic communities, particularly invasive gobiid fishes, dreissenid mussels, and their interactions.

CATALINA CLAUS
Feeding behaviour of invasive goldfish.

For my MSc research, I will be investigating the impacts of human behavior and the cultivation of super invaders, the wild goldfish. Goldfish are native to Asia but have spread to North America mainly through pet release. I will be focusing on the interactive effects of climate change and goldfish invasion, by looking at the adaptions from cultivated to wild populations. Using functional response experiments to quantify feeding behaviour, I aim to predict their impact by comparing consumption rates at various temperatures. I will compare goldfish populations from different environmental contexts: pet stores, urban ponds, and natural ponds.

BRIELLE COMARTIN
Impacts of zebra mussel invasion on native freshwater mussels in a Quebec lake.

With collaborators from the Quebec Ministère des Forêts, de la Faune et des Parcs, I am investigating the impacts of zebra mussel (Dreissena polymorpha) invasion on native unionid mussels in Lake Memphrémagog, southeastern Québec, where the zebra mussel has been spreading in recent years. For my MSc research, I am primarily interested in the role of biofouling by zebra mussels on unionids in Memphrémagog in population collapse, and whether these events are predictable. This lake allows me to study the effects of zebra mussels under relatively low calcium concentrations (<20mg/L), which can limit zebra mussel abundance, and compare these effects to those documented in calcium-rich environments. The results will be used to develop enhanced risk assessment tools for predicting zebra mussel impacts on native biodiversity.