Staff in North Cowichan have been directed to develop an action plan to deal with water issues in Somenos Lake, and the municipality will work with the Somenos Marsh Wildlife Society to modify the current and ongoing water-quality sampling work at the lake after the massive and sudden fish die-off there in August of 2024.
As well, North Cowichan council decided at its meeting on Dec. 18 that $58,000 will be added to the municipalityB次元官网网址檚 2025 budget for water-quality initiatives in Somenos Lake as part of a strategic partnership with the Cowichan Valley Regional District in an effort to deal with the issue.
Most of the thousands of dead fish that surfaced in Somenos Lake during the approximately two-day die off in early August were pumpkinseed fish, which is an invasive species, along with several hundred coho salmon and fewer numbers of other species.
Members of the Somenos Marsh Wildlife Society said at the time that while fish kills are not uncommon in Somenos Lake, this incident was the biggest one they had ever witnessed.
A statement from the Ministry of Environment and Climate Change soon after the event speculated that the fish kill was most likely the result of low oxygen and warm-water temperatures in the lake, and a report by Dave Preikshot, North CowichanB次元官网网址檚 senior environmental specialist, that was presented at the meeting on Dec. 18, largely concurred with the ministry, noting that poor summer water quality and cyanobacteria blooms, also known as blue-green algae blooms, have long been recognized as management concerns for Somenos Lake.
Preikshot said investigations into the lakeB次元官网网址檚 water quality conducted in the early 1900s and subsequent work on Somenos and Quamichan lakes concluded that poor water quality, algae blooms, and fish kills are rooted in extremely high sediment-phosphate concentrations resulting from land clearing and land use in the early 20th Century.
B次元官网网址淭he effects of poor-water quality and cyanobacteria blooms extend beyond fish kills,B次元官网网址� he said. B次元官网网址淐yanobacteria blooms can be harmful to human health and are known to have caused the death of companion animals in our community.B次元官网网址�
Preikshot said that while management of fish populations is a matter for federal and provincial agencies, water quality is an issue that has become of increasing concern to municipalities and regional districts, and North Cowichan already devotes money and staff time to monitoring both Somenos and Quamichan lakes as part of a service agreement with the Somenos Marsh Wildlife Society, with a view to improving water quality and mitigating cyanobacteria blooms.
He said the information provided by the monitoring of the lakes is an important component of designing an aerator and nutrient suppression technology to accomplish those goals.
B次元官网网址淔urthermore, such information is required by provincial and federal agencies that can partner with North Cowichan on such management work, and it will be a necessary component of their licensing management projects to improve lake water quality,B次元官网网址� Preikshot said.
Preikshot said the current program to monitor water quality in Somenos Lake provides an understanding of water quality issues and how these issues manifested as events like the fish kill in August, and in combination with an approach outlined at a workshop on the issue that was held in November, North Cowichan can use this existing work to develop a modified water quality sampling program for Somenos Lake which will help leverage support from federal and provincial agencies to monitor key parameters and develop actions to improve water quality in the lake.
He also recommended that North Cowichan enter into a strategic partnership with the CVRD for 2025 to access $58,000 for water-quality initiatives in Somenos Lake and its watershed, which got the green light from council.
