Humans affect freshwater ecosystems in many ways, including: 

1. Population expansion (i.e, the development of new structures)
This could lead to the redirection of natural water flows to provide for human use in towns and cities.

2. The direct (or indirect) disposal of human-made by-products which causes pollution
This includes industrial runoff alongside fertilizers and pesticides from the agricultural industry which can end up in rivers and streams, either by being dumped directly, or by being carried there by the rain.

3. The draining of the waters’ resources by overfishing
Some online studys claim that we will runout of seafood by 2048 if drastic changes aren’t implemented.

Professor Marguerite Xenopoulos from the Department of Biology at Trent University is hoping to hone in on how detrimental our footprint is on natural ecosystems at both local and global levels.

Marguerite’s research focuses heavily on the study of aquatic contaminants and the threat they pose to our environment.

In Marguerite’s lab at Trent-U, she and her research team are using the following research fields to answer some of these dizzying questions:

Why is the water of Lake Simcoe and its catchment browning?

Lake Simcoe is the 4th largest lake in Ontario with a catchment of 2480 km2.

Marguerite and her research team are attempting to better understand the origin and magnitude of the increasing organic matter in the lake’s water and its potential knock-on effects.

This research is in partnership with the Ministry of the Environment, Conservation and Parks.

How do you project global change in freshwater biodiversity through the use of conceptual and statistical tools?

The goal of this research is to develop statistical models that relate proximate drivers (climate, land-use, acid rain, etc.) to patterns of global biodiversity. The results of this research will be used to predict future shifts in biodiversity and their projected climate and environmental changes. 

What are the effects of Nanomaterials in the aquatic environment?

What is a nanomaterial you ask? A nanomaterial is a chemical substance that’s manufactured and is nanoscale in size! While Marguerite and her team acknowledge that nanotechnology has the potential to be very beneficial for society, they are still very unsure of its effects when it’s released into natural water systems. To answer these questions, the team is releasing silver nanoparticles in a lake at the Experimental Lakes Area and quantifying its fate and effects.

To learn more about Marguerite’s research and ongoing exploration into global change and its effects on aquatic communities in lakes and rivers, visit her website at

About Dr. Marguerite Xenopoulos:

“I am a full time Professor in the Department of Biology. I held a University Faculty Award position from Canada’s Natural Sciences and Engineering Research Council (NSERC) and am the recipient of the Early Researcher Award from the Ontario Ministry of Research and Innovation. I was born in Montréal where I completed a B.Sc. (1995) at the Université du Québec à Montréal (UQAM). I completed an MSc (1997) under the supervision of Dr. David Bird at UQAM followed by a PhD (2001) with Dr. David W. Schindler from the University of Alberta. Before arriving at Trent University, I was an NSERC postdoctoral fellow (2001-2004) in the lab of Dr. David Lodge at the University of Notre Dame, USA.”