By: Tineasha Brenot
Nestled in the heart of Central Ontario, Fleetwood Creek runs through a rolling landscape of eskers and kames. Deep, well-connected forests create a picturesque scene in every season with brilliantly coloured trees and shrubs fighting for their chance in the spotlight. From a highpoint in the watershed, the creek can be seen winding through wetlands and marshes. It’s not surprising that the beauty of these areas can be attributed to their large swaths of natural land consisting of forests, wetlands and of course, the creek itself.
Standing on the edge of the creek, I can feel the cool air from the headwaters trickling down through the water system. Sheltered by the large trees and understory plants, the water here is sheltered from the heat of the sun. Further downstream is a different story. A decrease in creekside vegetation is noted as a result of years of agriculture. The temperature has changed; warming from where it had flowed out of the ground. A lack of vegetation lining the stream, as well as the presence of man-made shallow dug ponds can cause stream temperatures to rise, leading to the decline of sensitive cold-water stream ecosystems. This rise in temperature makes the stream unsuitable for many species of insects, invertebrates and fish.
Fleetwood Creek is home to a sensitive species of fish called Brook Trout (Salvelinus fontinalis). These colourful jewels of the creek are one of the few native Salmonid species that naturally occur in Ontario. Brook Trout inhabit clean, cold-water streams and are sensitive to changes in their habitat, making them a great indicator of the overall health of a stream ecosystem. Southern Ontario has seen an 80% decline in Brook Trout populations, raising a number of questions as to why these fish are disappearing.
The loss of cold-water stream habitat is not the only factor that threatens Brook Trout. Unlike many other species of Salmonids, Brook Trout are poor jumpers. This can be really problematic during storm events and spring melts when rushing water can push Brook Trout downstream. Throughout the heated summers in Ontario, parts of Fleetwood Creek see a drastic reduction in the volume of water travelling through its tributaries, so much so that some areas of the creek will completely dry up. This can leave populations naturally separated from one another that is often restored during the next heavy rain.
Human-made structures such as roadways, bridges and dams complicate the natural flow of rivers, streams and creeks. Perched culverts are formed when water passes through a culvert that is narrower than the width of the stream, forcing water to shoot out the other side. The force of the rushing water erodes the stream bed leaving the outlet to sit higher than the downstream water surface. When culverts are severely eroded to the extent that water pours out of the downstream outlet, fish are unable to migrate to parts of the stream that are important for different life stages such as spawning and development of juvenile fish. In Fleetwood Creek, perched culverts are a barrier to Brook Trout that are unable to jump to the disconnected stream.
Identifying where problems exist is the first step towards reducing the barriers to survival for many species in decline. By identifying where the perched culverts are throughout the watershed, local not-for-profit and environmental organizations have been able to partner with landowners to tackle issues impacting connectivity of the creek. These organizations have been able to provide expertise and guidance to landowners looking to manage their properties with the surrounding landscape as a priority by connecting them to financial assistance programs and stewardship resources. Replacing perched culverts with infrastructure that allows for better water flow is a great way for landowners to restore the connectivity of the creek, allowing for fish like Brook Trout to migrate through the watershed.
About the Author
After receiving her BSc in Biology from Trent University and a Graduate Certificate in GIS from Algonquin College, Tineasha was able to pursue a career in conservation biology to help satisfy her love of nature and ecology. She has worked throughout much of southern Ontario focusing on ecosystem restoration, citizen science, plastic pollution, reptile and amphibian ecology and invasive species. Tineasha is currently part of the youth ambassador program Ocean Bridge where she expands her understanding of ocean literacy and conservation issues through community engagement and mentorship. Tineasha continues to be a lifelong learner of the natural world around her, seizing every opportunity to be a better naturalist and ambassador for our planet.