PRINCE GEORGE, B.C.  –The Ministry of Environment in conjunction with the Northern Health Authority is advising the public that area lakes and associated backwaters across the Omineca Region may be susceptible to blue-green algae (cyanobacteria) blooms which may pose a health risk for livestock, humans and wildlife. The presence of cyanobacteria has been reported and confirmed at Tachick Lake and Cluculz Lake and may be visible in other regional waterbodies.

 

On Tachick Lake and into the Stoney Creek drainage, two dominant species of blue-green algae have been identified: Microcystis aeruginosa and Aphanizomenon flos-aquae. Additionally, the presence of the toxin Microcystin-LR, which is commonly associated with livestock poisonings, is confirmed at values ranging between 0.3 – 1.1 µg/L. Blue-green algae has also been confirmed on Cluculz Lake, with one dominant species identified: Aphanizomenon flos-aquae. The presence of Microcystin-LR was at the detectable limit (0.2 µg /L). No toxicity levels exceed the Canadian Drinking Water Quality Guidelines maximum acceptable concentration of 1.5 µg/L.

 

Despite the low values, the microcystin toxin can be spatially variable within algae blooms, and because of this, the MOE continues to advise the public that there is a potential health risk associated with these blooms.

 

 

Blue-green algae blooms are relatively common throughout the Omineca-Peace region. Seasonal conditions and the fall turnover in lakes may be creating ideal conditions for blue-green algae growth. This condition is generally called a “bloom” and is typically seen on the water surface as “pea soup”, or a thick, oily, often turquoise/whitish slick. Although algae blooms are a naturally occurring phenomenon, water bodies which have been enriched with phosphorus from human sewage, livestock waste, fertilizers and/or detergents may experience enhanced growth of algae.

 

These blooms are unsightly, strong smelling and, if ingested, may be toxic to livestock, humans or wildlife. Because of the objectionable appearance and odour of these blooms, older children and adults are not likely to intentionally drink water containing blooms. Younger children who may be less careful should not be allowed to swim or wade in lakes with visible floating blooms. Blooms are often most concentrated along shores that are exposed to onshore wind.

 

If water containing toxic cyanobacteria is ingested, symptoms such as fever, dizziness, headaches, stomach cramps, vomiting or sore throat may appear and persist for several days. Exposure to the toxins by swimmers has resulted in symptoms that include skin rash and irritation around the eyes.

 

 

Because bloom toxicity is difficult to confirm all blooms should be treated seriously and the following precautions followed if a toxic bloom is suspected:

·       do not wade or swim in water containing visible blooms. Contact with blooms may cause skin irritation.

·       do not allow livestock or pets access to water containing visible blooms.

·       do not take drinking water directly from waterbodies with visible blooms. While all potable water from surface sources should be disinfected, this will not destroy toxins generated by cyanobacteria. These toxins are also temperature resistant and will not break down through boiling.

 

Most blooms are short lived and an affected area will likely be safe in a number of days or up to two weeks.