Have you ever thought about what affect pesticides have on our aquatic environment? 

Selby Sawyer,  a 4th year Trent University student is dedicated to finding out!


She is doing her undergraduate degree in Biology and Environmental Sciences and is studying a Neonicotinoid pesticide, called Clothianidin, and its affect on the Rusty Crayfish – an invasive species to Canada. 

Commonly used for agriculture purposes throughout North America since the late 1700s, Clothianidin helps keep our crops safe from insects.

An estimated 20% of the chemical are taken up by crops themselves…but the rest of the it ends up running off into nearby bodies of water.

This is a problem for many reasons – as this insecticide is known to have negative ecological consequences. Currently, we have a pretty good understanding about how pesticides impacts land species…but very little is known about how Clothianidin affects aquatic organism behaviour and physiology.

Selby’s research focuses on how constant runoff of pesticides affects the Rusty Crayfish.


She collected Rusty Crayfish at storm ponds nearby Trent University and set up minnow traps to catch them & bring them back to individual housing containers for trials.

During the 1 day trials, the Rusty Crayfish were exposed to a concentration level of Clothianidin found in nearby water bodies that exceed environmental guidelines and compared with a control group that had no exposure.

Clothianidin exposure may impact the Rusty Crayfish’s ability to smell. Smelling is crucial for the Rusty Crayfish to find their next meal – and not being able to smell can make these species more aggressive, leading to fighting with others for scarce resources. In some cases, the Rusty Crayfish have completely taken over native fish species in areas very quickly. 

This may ultimately negatively disrupt the environment they live in.

Selby is currently in the middle of running trials and she expects to find that the Rusty Crayfish are more aggressive toward each other and spend less time looking for food… because they can’t sniff out their meal because of the Clothianidin pesticide.

It is crucial to understand the impact pesticides have on our environment and place heavier regulations about how much can be released.

Regulations can help phase out some of these harmful pesticides and help protect our environment-  both terrestrial AND aquatic.

Thank you Selby for your important work on pesticides and their affects on our ever-changing aquatic environments. 

Here is what Selby has to say about her Trent experience.

“When I first visited Trent, the one aspect I loved was how close the community seemed and the relationship you can build between faculty and student. And doing this thesis really showed that even more. You don’t have to be afraid to reach for help or advice from others whenever at Trent. The faculty are welcoming and understand that even though there is independence when doing research, you are also there to learn from them and are willing to help in any way they can. After this opportunity I have realized a new confidence in me and my academic abilities I did not realize before, and I couldn’t be more grateful to the faculty at Trent that have helped me on this journey to where I am now.”