Hanlon Creek eDNA and Electrofishing Survey: After months of planning with partners from the University of Guelph and local consulting firms, NRSI and SLR, a very interesting project have been undertaken on Hanlon Creek in Guelph, ON. The goal of this project was to combine a traditional electrofishing survey with newer eDNA (environmental DNA) technology to detect the presence of a thriving Brook Trout population in Hanlon Creek.
On September 14th, 2019 a group of students, professors, lab technicians, TUC personnel, and consulting biologists worked all day to electrofish and sample for eDNA in five different sites along Hanlon Creek in Preservation Park.
Electrofishing is currently the standard method to physically observe what species are present in a watercourse. However, this method has limitations regarding the timing that a survey can be conducted and can harm fish that are caught. EDNA lets us test a watercourse for a species (in this case Brook Trout) simply by taking a sample of the water that they inhabit. The water sample is then tested for DNA that has been shed from the species and now exists in the environment. This is a much less invasive method than electrofishing and can be done at any time; however, it is relatively new so there is a lot we are still learning about eDNA.
There were many purposes of this combined survey. It tested if the cold-water species Brook Trout still populate this area, which can lead to conclusions about overall stream health and potential future conservation projects. It also allowed for a comparison between traditional techniques of species detection and new techniques to answer the question– is eDNA a good method to test the presence of Brook Trout in a watercourse or does electrofishing do the trick just fine? This project was also a great opportunity to integrate university-level learning with community partners and allowed the fourth year Biodiversity students involved to get some real-life experience with professional members of the community.
During the survey, we were able to catch 16 healthy Brook Trout and many other fish. EDNA results are still being analyzed in the lab; however, we were successfully able to detect Brook Trout eDNA. The combination of these two methods confirmed the presence of Brook Trout in this area of Hanlon Creek. This is great news that indicates that Hanlon Creek continues to be a healthy, cold-water habitat!
The Guelph students plan to return to Hanlon Creek later in the Fall with the hopes of conducting two more rounds of eDNA sampling to capture Brook Trout spawning. Typically, electrofishing cannot take place during spawning seasons to avoid harming the fish during this sensitive time.
After completing this project, it will be interesting to see how these new and traditional surveying methods can be combined to inform and plan future conservation, restoration and protection of Canada’s waterways.
For more details, check out the Guelph student’s website.
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