Brown Trout Redd Counts
Brown Trout are fall spawning trout, unlike Rainbow Trout that spawn in the spring. These redd counts (redds are trout spawning nests) are conducted in November after spawning by the Brown Trout has occurred, a behavior that is believed to be triggered by changes in the duration of daylight hours, and perhaps to a lesser degree, by a drop in the river water temperature.
The Brown Trout Redd Count project is supported by funding from City of Calgary Water Services. Calgary River Valleys greatly appreciates the support provided by the City of Calgary for this important citizen science monitoring project. The data from our Brown Trout Redd Counts is one indicator of the health of the river ecosystem, as Brown Trout will only spawn in water that is low in sediment, has sufficient dissolved oxygen, is cold enough, and has sufficient flow.
We have been collaborating with other groups to count redds, of Brown Trout in the lower Elbow River since 1994, and we have been the main organizer of this important project since 2009. Why do we keep doing it every year? We believe it is important to ensure this project continues as an annual count in order to ensure the data collected is as accurate as it can be, that trends over time can be observed, and the location of redds can be used to ensure land use decisions don’t negatively impact Calgary’s blue-ribbon trout fishery.
2024 Redd Counts
This year was our first year to conduct three Brown Trout Redd Counts. We built on the work completed in 2023, and conducted two days of counting on the Bow River, repeating the same approximately 10 km reach between West Baker Park and the Parkdale Boat Launch in Point McKay, then counting redds again the following day, starting where we left off, from the Parkdale Boat Launch and finishing at St. Patricks’ Island, which was another approximately 10 km reach. We were also able to complete our usual count on the Elbow River between the Glenmore Dam and Fort Calgary, which covers approximately 12 km.
Bow River Redd Counts
The first redd count on the Bow River in 2024 was conducted on Saturday October 26 with 11 volunteer citizen scientists, 2 professional raft guides, and 1 professional biologist who trained everyone how to recognize and consistently count the current year’s Brown Trout redds prior to departure. The weather was again sunny and ideal for spotting the light coloured mounds of gravel that are the freshly created redds (spawning nests) of Brown Trout.
This was the second year of counting redds in this reach of the Bow. While in 2023 we counted 232 redds in this reach, this year, the number was significantly fewer. We have included some pictures from our Bow River Brown Trout Redd Count.
Elbow River Redd Count
The count on the Elbow River took place on November 1, 2024, with 12 volunteer citizen scientists, 2 professional raft guides, and 1 professional biologist who again trained everyone how to recognize and consistently count the current year’s Brown Trout redds prior to departure from the base of the Glenmore Dam. We also had several volunteers and 2 staff from Calgary River Valleys who provided parking for vehicles at the meeting location at Fort Calgary, waders for volunteers to use, hand & foot warmers, a hot lunch at Stanley Park, and access to washrooms at the stops.
We have included some some pictures from the Elbow River Brown Trout Redd Count from November 1, 2024, as well as the up-to-date chart of the numbers of redds counted.
Please contact us if you want more detail on the locations of the redds within the river.
Brown Trout Spawning Education
Brown Trout live in the Elbow and Bow Rivers year-round. They spawn in both rivers, and also in some of Calgary’s larger creeks, such as Nose Creek. When Brown Trout spawn in the fall they can be seen from above from many of Calgary’s bridges in late September & through October each year.
It is often easier to see the fish through the water when the sun is shining in mid-afternoon and when there is little to no wind, so there are very few ripples on the water’s surface. In addition, using polarized sunglasses can greatly improve the ability to distinguish the fish from the river bottom.
2024 Spawning Education
Calgary River Valleys staff held 2 educational sessions on the Peace Bridge to engage with members of the public and talk to them about the life cycle of Brown Trout in our rivers. These were held on October 12 and 19, 2024.
Here are some pictures from the Brown Trout spawning education sessions CRV conducted in October. You can clearly see the lighter areas of river gravels that indicate these are new Brown Trout redds, with other trout waiting to spawn in the same area (the dark shapes).
