When the Capital Regional District officially implemented its new tool to battle ongoing blue-green algae flareups in two of its lakes, it warned things could get worse before they got better.
That’s proved true with a months-long flareup at the conjoined bodies of water at Elk and Beaver Lake Regional Park in Saanich. Both are frequently the subject of water quality alerts due to the algae that can produce cyanotoxins.
High nutrient levels have contributed to algae blooms, low dissolved oxygen levels and decreasing water clarity. In 2018, the CRD released a report identifying technology to increase oxygen levels in the lakes and reduce the occurrence of toxic blooms. Even as it was installed two years ago, the CRD warned vegetation and blue-green algae could temporarily increase once the system first started operating.
The system was fully commissioned in March 2024, and by the end of April 2024, the system reached its 14th month of operations. Staff knew, from discussions with the consulting team leading the project, that any oxygenation solution would take 18 months or longer, the CRD said in a written response to the Saanich News.
There was also a greater potential for blooms in that year, up to an 18-month period, shown by oxygenation systems installed in other lake systems.
“For context, algal blooms are being observed in all our lakes throughout the region on a more regular basis,” the CRD said. “This is a broader phenomenon being seen across the continent and the globe.”
The frequency and intensity of blooms are shaped by several factors – nutrient levels, ambient temperature, sunlight, and wind patterns – making it difficult to predict exactly when conditions will align to trigger an outbreak. That leads to an ebb and flow of intensity and recently resulted in a last-minute cancellation of an Ironman swim at the lake.
“Once we reach approximately the 24th month of operation, staff will bring forward next steps, which may include reengaging the province and other stakeholders that play a role in the overall health of the watershed,” the CRD said.
Performance tracking for last year shows improved conditions in three of the four success parameters staff monitor.
In the meantime, the district and Island Health continue to monitor levels and alert users because those toxins can be dangerous, even deadly, to both humans and canines.
Swimming exposes people to cyanotoxins in a few ways, according to Dr. Ka Yan Xu, resident physician in Public Health and Preventive Medicine for Island Health.
“While swimming, you may accidentally ingest the water. This is especially of concern for children, who usually spend more time in the water and are more likely to accidentally swallow the water. Swimming also means that there is direct contact with the skin and eyes, and the potential to breathe in water droplets containing cyanotoxins,” Xu said in a written response to the Saanich News.
“To protect your health, stay out of the water and avoid contact if blue-green algae is suspected or warning signs are posted. If you’ve been exposed, watch for symptoms and seek medical care if any appear.”
Even activities such as playing, wading or water skiing can increase the risk of exposure. The impacts vary based on the amount, duration, and route of exposure.
“Children are particularly at risk because their smaller body size means even small amounts of toxin can cause more severe symptoms,” Xu said.
Mild effects include irritation of the skin, eyes, nose, and throat. Some may experience flu-like symptoms such as headaches, muscle weakness, and fever, or gastrointestinal issues like stomach pain, vomiting, and diarrhea.
In more serious cases, the toxins can affect the nervous system, potentially paralyzing muscles used for movement and breathing, or accumulate in the liver, causing liver damage.
Death from cyanotoxin exposure is rare.
