Summer season can be hard for trout, salmon and other species that reside in and around the Tsolum River.
When air temperatures increase, water temperature in the Tsolum is quick to follow with temperatures in July and August often exceeding 200C.
While pleasant for swimmers, salmonids find the higher temperature stressful and behaviours such as feeding tend to decrease as water temperatures rise, affecting the overall health and growth of fish. When water temperatures rise above 230C fish deaths can start to happen.
The other issue with the Tsolum River at this time of year is lack of flow. At the end of July, the discharge (volume of water) flowing in the Tsolum was 0.34m3/sec. To put this in perspective, the average annual discharge is 10m3/sec, and winter flows often exceed 100m3/sec.
When the snowpack is gone, the flows in the Tsolum are sustained by rainfall, groundwater inputs and any surface flow from water stored in small wetlands and lakes further up the watershed. Wolf Lake has a DFO -operated dam at its outlet and for August and September DFO staff let water out from the dam incrementally to add water to Headquarters Creek which flows into the Tsolum. The purpose of adding or augmenting the flow is for fish habitat conservation and the Pink Salmon return that begins in August.
While it can be a difficult time of year for fish to survive and thrive, there are things we as stewards and residents can do to help fish during these stressful months. Please do not build small dams across the river.
While it is nice to create your own pool, keep in mind that dams impede fish migration and small fish (and soon adult Pink Salmon) regularly move throughout the watershed. If your dam is blocking water flow, it can be obstructing passage for baby fish.
Avoid using sunscreen before swimming in the river, and any soap products including biodegradable soaps that are toxic to fish and aquatic insects, especially when flows are low. Biodegradable soap suds should be disposed of in soils away from watercourses where it can break down.
We know that dogs need to cool down too, but in the third week of August, adult Pink Salmon will enter the river and hold in pools. These are the same places where dogs like to play fetch with owners; please consider taking your dog to another location such as the ocean during August and September.
Finally, remember that the Tsolum River is permanently closed to all fishing, which includes catch and release. This is because the fish stocks are still in recovery after 40 years of copper mine pollution up until the mine site cover was put in place in 2010.
Tsolum River Restoration Society is about to start two projects in the Tsolum watershed. The first is the Dove Creek gravel trap, which is designed to intercept excessive bedload (boulders and other material) that is travelling down the system.
We are also starting our third year of willow live staking on the large gravel bars upstream of Highway 19. We are looking for volunteers to help with collecting willow cuttings and planting the stakes in early September. If you are interested in helping please contact us via www.tsolumriver.org or at the number below.
B.C. and World River’s Day is coming up on Sunday, Sept. 27. This is a day to appreciate our rivers and we are planning a physically distanced Tsolum River walk at the Comox Valley Exhibition Grounds. Details will be posted on our website or Facebook Page closer to the time.
If you see anything that concerns you in the river, please give us a call at 250-897-4670. We rely on and appreciate the concerns of many individuals who steward this precious river.
