Baseline water testing in Horse Creek last fall revealed two trout species that weren’t noticed there before.
In 2007, limited fish sampling captured brook trout in Horse Creek, located west of Cochrane, above a railway culvert.
More extensive sampling last September captured brook trout, brown trout and rainbow.
“It was interesting to find rainbow trout in Horse Creek as these small creeks are often completely dominated by brook trout, which often out-competes rainbow trout, cutthroat trout and bull trout in these smaller creeks,” said Scott Stoklosar, senior fisheries biologist.
The sampling was part of the Horse Creek Watershed’s Water Monitoring and Fisheries Assessment conducted last year.
The project was funded by the Little Creeks and Rough Fescue Appreciation (LCARF) Society, a non-profit group interested in understanding and managing the health and function of Horse Creek.
Last September, electrofishing was conducted at the Creek. Lower Horse Creek, located 300 metres north of the railway and within right-of-way at Highway 1A, and Middle Horse Creek, south of Horse Creek Road, were studied.
The Lower Horse Creek is where three rainbow trout, eight brook trout, 14 brown trout were observed.
In the Lower Creek, there is a perched culvert at the railroad.
“The three rainbow trout were too small to have moved through the culvert so it seems likely they were spawned in the creek by rainbow trout that entered Horse Creek in the spring and moved past the culvert,” he said.
A final report of the fisheries assessment said the culvert may be a year-round barrier meaning there is a resident population of trout in the Horse Creek, which spawns or the culvert is a partial barrier to fish movement but larger trout are able to pass through the culvert at certain times of the year when there is high flow conditions.
No trout were found at Middle Horse Creek.
More work needs to be done to assess the fish and fish habitat, including an investigation of the CP Rail culvert to determine if it is a complete or partial barrier to upstream fish movement, the report suggests.
Stoklosar said they don’t know how far upstream the trout are found and would be interested to hear from long-term residents of the watershed about their memories of trout and other fish in Horse Creek as it was thought historically to be a small, trout-bearing stream.
Sarah Leete, president of LCARF, said the society will do a second year of baseline water monitoring this year with volunteers and has committed support from the Land Stewardship Centre under their Water for Life program and the Town of Cochrane.
