There have been growing concerns about water quantity within the Little Campbell River as certain sections dry out completely during the warmest months of the year. As the river dries, aquatic habitat becomes fragmented and some fish and amphibians become confined to small pools. More than 5,000 salmon individuals inhabit and travel through the LCR annually, and the dry section is known to be spawning and rearing habitat in the fall for many fish species including coho salmon, chinook salmon, steelhead trout, and cutthroat trout. Salmon fry die from desiccation when confined to small pools that eventually dry up, and if the seasonal extent of the dry reach extends into the fall spawning season, spawning will be restricted to lower reaches and salmon populations may decline. The main drivers of changes in water quantity in the Little Campbell River include climate variability (consistently warmer temperatures and lower precipitation during the summer) and increased human extraction for irrigation, livestock watering, and domestic use.
A Rocha monitors the Little Campbell River’s dry reach beginning in June, when water levels drop, through the summer months until the river reconnects in the fall. Each week, we measure the length of the dry section, take water quality measurements, and salvage any salmon fry that have become confined to small pools by transferring them into the main section of the river. In 2018, portions of the river began to dry up in early June, and the dry extent peaked in mid-August at 1.6 kilometres long. The river did not reconnect until early November. With additional monitoring over multiple years our goals are to determine trends in the dry reach over time, assess impacts on salmon spawning and rearing, and ultimately inform management practices to protect and improve river health. This project has been funded by Fisheries and Oceans Canada’s Habitat Stewardship Program for Species at Risk.