Southern Ontario Pub Night - April 7, 2025

We are hosting a special Pub Night in Guelph at Royal City Brewing on Monday April 7 highlighting some of the interesting research done by undergraduate researchers across a few universities! Undergraduate students will be presenting their research in a short and sweet 5-minute talk format, with 1-2 minutes for questions after. This format will allow us to have presenters from multiple universities, each with their own special research interests, including talks centered on mixture toxicity, microplastics, and chemicals of emerging concern. Please join us for an exciting night of presentations, food, and drink.

Topics Including mixture toxicity, hypoxia tolerance, microplastic contamination, and chemicals of concern

Various Speakers from Wilfred Laurier University, University of Toronto, University of Guelph, and McMaster University

When: Monday April 7, 2025 | 7:00 pm doors; 7:30 pm talks

Where: Royal City Brewing Company, 199 Victoria Rd S (Additional parking behind building)

Cost: Pay what you can – help support our AGM student awards!

Make a donation here: https://www.laurentiansetac.ca/support-pubnights

Southern Ontario Pub Night - Undergraduate Showcase

April 7, 2025, 7:00–9:00 p.m.|Royal City Brewing

Register Now

Speakers

Vedant Gattani (U of T): Pecking on plastic: microplastic contamination in terrestrial birds

Originating from the breakdown of larger plastics and industrial activities, microplastics are now pervasive across global environments, including terrestrial ecosystems. While much research has focused on their effects on marine wildlife, little is known about their ingestion by terrestrial species such as songbirds. This study investigates microplastic ingestion in terrestrial songbirds, aiming to determine 1) how microplastic concentrations vary across different feeding guilds and 2) whether these guilds influence the types and sizes of ingested microplastics. A total of 70 bird carcasses, representing 34 species across five feeding guilds were analyzed. The gastrointestinal tracts were dissected, chemically digested, and filtered for microplastic extraction, followed by manual quantification. By identifying patterns of ingestion among foraging guilds, this research provides valuable insights into microplastic contamination in terrestrial ecosystems, further contributing to the understanding of its ecological consequences for avian species. The study’s findings hold significance for conservation efforts, highlighting the broader environmental impact of microplastic pollution and the necessity for strategies to protect avian biodiversity

Mustajab Khalid (WLU): The effects of venlafaxine and hypoxia on rainbow trout

Antidepressant prescription rates are increasing, leading to their excretion in a neuroactive form that often bypasses wastewater treatment plants and contaminates surface waters. Within these aquatic environments, multiple stressors exist, including low oxygen levels (hypoxia) resulting from anthropogenic activities like agricultural runoff. Fish detect changes in oxygen using gill neuroepithelial cells (NECs), which use serotonin to engage coping mechanisms. Fish have developed behavioral adaptations like increased opercular movement and aquatic surface respiration to cope with hypoxia. Considering that venlafaxine, a widely prescribed antidepressant, works by inhibiting the reuptake of serotonin and norepinephrine, how might hypoxia tolerance be affected when exposed to venlafaxine? This study investigated venlafaxine’s potential impact on oxygen sensing in juvenile rainbow trout (Oncorhynchus mykiss). We exposed fish to control, two environmentally relevant concentrations of venlafaxine (0.1 and 1 µg/L), or a higher concentration (10 µg/L) for 24 hours in 12L tanks. Fish were placed into a flow-through system to gradually reduce oxygen levels to 10% dissolved oxygen until loss of equilibrium (LOE) occurred. LOE is often measured to determine extreme hypoxia tolerance. Behavioural metrics such as distance, velocity, and time to LOE were quantified using EthoVisionXT tracking software. Aforementioned behavioural metrics were not significant among treatments. But after hypoxia testing blood glucose levels were collected to measure energy mobilization. Blood glucose levels were significantly lower in the 1 and 10 µg/L treatments compared to the control. This suggests that high concentrations of venlafaxine act as a potential beta-blocker during severe hypoxia and may impair energy mobilization.

Emily O (McMaster): The effects of liquid crystal monomers on zebrafish (Danio rerio) reproduction

Liquid crystal monomers (LCMs) are mass-produced for screens across a wide range of electronic devices, including phones, TVs, and laptops. As these devices are manufactured, used and eventually recycled, LCMs are inadvertently released into an abundance of environmental matrices making LCM pollution an escalating issue. LCMs are emerging chemicals of concern due to their persistence and bioaccumulation, highlighting the urgent need for toxicity research. Preliminary work in this field has focused on in vitro and in silico models to predict the potential fate and adverse outcomes of LCMs. While in vivo studies on LCMs remain limited, there has been evidence of reproductive toxicity from LCM exposure in daphnia that led to endocrine disruption and reduced reproductive output. This study investigates the hypothesis that prolonged LCM exposure decreases reproductive success in zebrafish (D. rerio), a widely used model organism to assess toxicity risks to human health and aquatic health. To test this, zebrafish were exposed to concentrations of a fluorinated LCM (CAS: 174350-05-1) relevant to human exposure levels for 24 days. Exposure to 1.7 ng/L, 17 ng/L, and 170 ng/L of LCM was found to negatively impact reproductive output, quantified by a lower cumulative total of embryos produced per treatment. At the highest dose, parental exposure to 170 ng/L LCM was found to increase developmental abnormalities in offspring by approximately 24-fold compared to the control. Future research should examine how LCMs impact gene expression, hormone levels, and reproductive organs to better understand the potential risks they pose to human health. Ultimately, the research on the pollution of LCMs in Canada will become exceptionally important in the near future as we race to understand the fate and toxicity of these emerging chemicals of concern.

Raveena Parsa (McMaster): Characterizing the metabolic capabilities of the cytochrome P450 1 family in zebrafish (Danio rerio)

Xenobiotics, or toxic chemicals which do not occur naturally, can be harmful even at low concentrations. The mechanism through which fish process these chemicals occurs through the “chemical defensome”, a large collection of genes responsible for the biotransformation and detoxification of xenobiotics. The Cytochrome P450 (CYP) enzymes are particularly important in the chemical defensome. CYPs are evolutionarily conserved across all domains of life, with CYP1 primarily facilitating detoxification through monooxygenation reactions, involving two electron transfers by NADPH. While CYP1 enzymes are known to aid in detoxification, the specific roles of each CYP1 isoform in fish remain unclear. This study expanded on previous work, where a high-throughput screen of a large bioactives library was conducted. A small group of “top hit” compounds from this previous work was generated to test against individual CYP1 enzymes in zebrafish (Danio rerio). CYP1A, CYP1B1, CYP1C1, CYP1C2 and CYP1D1 activity were evaluated in vitro with the goal of identifying compound classes with shared activity across these isoforms, to further our understanding of this family. NADPH consumption was evaluated as the proxy for enzymatic activity. We hypothesize that CYP1A, CYP1B1 and the CYP1Cs will share similar NADPH consumption rates for all compounds that are bound by aryl hydrocarbon receptors. We also hypothesize that CYP1D1 will not share any NADPH consumption rates for these compounds. This research is relevant to environmental toxicity and health, and provides a foundation for in vivo studies in zebrafish, enabling more efficient and targeted compound selection.

Logan Dammer (WLU): Refining cell culture test methods for environmental protection

The 2023 revisions to the Canadian Environmental Protection Act (CEPA) have led to commitments to eliminate vertebrate testing. This will pose challenges for Environment and Climate Change Canada seeing as environmental quality guidelines depend on toxicity tests of vertebrates (e.g fish). Alternative methods are the answer to overcoming these challenges. By observing the responses of cultured cells exposed to copper concentrations we can uncover obstacles and work towards solutions. Cell cultures were used as an alternative method to observe the effects of copper and its free ion forms. Cells from the cell line RTG-2 (rainbow trout gonad) were exposed to high and low ranges of copper on a 96-well plate, to effectively measuring the cell viability. Different geochemical variables will be employed to observe the bioavailability of metal ions and corresponding cellular effects. Using simulation programs and free ion electrodes, the free ion concentrations under different environmental conditions will be measured. The cell viability assays showed the toxicity of copper to not be considerably strong when below 160 mg/L. The simulator showed numerous non-toxic products formed from the complexations of copper with components in the growth media, which reduce cytotoxic effects. Regulations in Europe like registration, evaluation, authorization and restriction of chemicals (REACH) drive the reduction in animal use around the world. This research aims to provide reliable metal toxicity data that can be used as an alternative to vertebrate testing for water quality guidelines in Canada. Research supported by NSERC and Environment and Climate Change Canada.

Ravleen Kaur (WLU): Impacts of chronic neodymium exposure of fathead minnows and arctic char

The increasing prevalence of Neodymium (Nd), a rare earth element, in aquatic ecosystems due to industrial runoff necessitates an understanding of its chronic effects on freshwater organisms. This study investigates Nd bioaccumulation in Fathead minnows (Pimephales promelas) both adults and juveniles, and Arctic char (Salvelinus alpinus) alevins under controlled laboratory conditions. Adult minnows were exposed to sublethal Nd concentrations (100, 200, and400 µg/L) for 96h in a flowthrough system, maintaining water parameters (80–100 µs/cm, 10–40 mg/L hardness, pH 7.2, and 19–21°C) to reflect natural conditions. Tissue samples from gills, liver, kidney and muscle were analyzed for Nd accumulation. Juvenileminnows were exposed to either 50 and 100 µg/L Nd for 72h under similar conditions, with whole-body samples collected for analysis. Arctic char alevins underwent a 3-week exposure of 7 Nd concentrations (10–640 µg/L) in soft water (200–205 µs/cm, 80–95 mg/L hardness, pH 6.9–7.5, and 7°C), and whole-body samples were examined for bioaccumulation. Findings from this study provides crucial insight into the extent of Nd accumulation across different life stages and species, highlighting potential ecological consequences. By identifying Nd bioaccumulation patterns, this research informs environmental risk assessments and supports the need for regulatory measures for environmental protection.

Jacob Gawronski (Guelph): Assessment of microplastics in Lumbricus terrestris in fields amended with and without biosolids

The accumulation of microplastics in agricultural soils amended with biosolids has raised significant environmental concerns. This study investigates the presence and characteristics of microplastics in earthworms (Lumbricus terrestris) collected from fields treated with biosolids. By focusing on these organisms as a bioindicator for microplastic contamination in soil, this research provides insights into microplastic exposure and potential harm to soil biota and thereby pedologic processes. Worm tissues were processed using a digestion protocol involving hydrogen peroxide oxidation followed by a density separation with sodium bromide. Microplastic content was visually identified and quantified usingmicroscopy, revealing patterns in particle size, microplastic morphology and abundance. Results showed a statistically significant difference in accumulation of microplastics in worms from biosolid-amended fields compared to control sites, strengthening thepossibility of biosolids as a vector for microplastic contamination. These findings underscore the need for improved biosolid management practices to mitigate environmental microplastic pollution and its associated risks. Future research will assess the microplastic content of Lumbricus terrestris subject to different biosolid amendment types and refine methodologies isolating microplastics in biological tissues for analysis.

Speranza Martin (Guelph): Altered Ecosystems: Ant-Aphid dynamics in agricultural settings

There is a research gap regarding the role of ants (Hymenoptera: Formicidae) in agricultural systems, particularly in understanding how pesticide exposure affects their structured behaviours and interactions with other beneficial organisms. The intricate mutualistic relationship between ants and aphids plays a significant role in ecosystem stability and agricultural health, however, the widespread use of pesticides poses potential threats to this delicate balance. This study investigates the impact of pesticide exposure on ant-aphid interactions, aiming to elucidate the mechanisms by which chemical treatments alter these dynamics. The species L. neoniger and M. persicae were introduced onto pepper plants in controlled environments subjected to various pesticide stressors. Throughout the experiment, survival, behavioural shifts, and interspecies interactions were monitored. The results are currently pending. Understanding the nuanced effects of pesticides on ant-aphid dynamics is crucial for developing more sustainable agricultural practices and preserving ecosystem integrity. This research underscores the need for integrated pest managementapproaches that consider the complex interactions within ecosystems, promoting resilience against chemical disturbances.