Author: Rina Guxholli
Canadian freshwater fishes are a highly diverse group of vertebrates that have experienced catastrophic population declines. To monitor declining populations, conservation efforts are employed through traditional capture-based methods. However, these techniques are often labour-intensive, time-consuming, and environmentally invasive. The use of environmental DNA (eDNA) has emerged as a monitoring tool for Canada’s freshwater fishes. The tool used to analyze eDNA is quantitative polymerase chain reaction (qPCR). It relies on the use of short DNA sequences called primers and probes, together known as assays, to bind to DNA unique to each fish species. There is currently a lack of robust, specific, and sensitive qPCR assays for Canadian freshwater fishes. This project has two objectives to address this gap. The first is to develop species-specific qPCR assays to detect 20 Canadian freshwater fishes found in New Brunswick. The second is to test the assays on eDNA samples from freshwater systems at Fundy National Park to prove efficacy and utility as a monitoring tool. Results from this project include assay development techniques, qPCR protocols and primer/probe sequences. These assays strongly amplified target DNA and produced little to no off-target amplification of DNA from other commonly found species. We discuss further initiatives regarding the testing of these assays on eDNA samples taken at Fundy NP. This project aims to create a set of eDNA assays used for sensitive, non-invasive, and practical monitoring of New Brunswick freshwater fishes. It will significantly complement traditional surveying methods to allow for more robust and accurate assessments of target freshwater fishes. These resources will not only allow for improved monitoring practices in New Brunswick, but also throughout the geographic ranges where these species are found. These enhanced monitoring tools will further promote the sustainability of fish populations as it extends to the health of freshwater ecosystems locally and nationally.
