Algae advisories issued for beaches

Blue-green algae advisories were in place for a handful of Manitoba beaches Wednesday — ahead of an August long weekend that is expected to be warm and sunny — after high levels were detected during water-quality tests.

The province urged people not to swim, drink or make contact with water where green scum is visible, and to keep pets and livestock away because toxins, if present in the algae, can be fatal to animals.

People should avoid eating fish that appear unhealthy.

Advisory signs were recently posted at beaches at Brereton (south) in Whiteshell Provincial Park, Hoopers, Minnedosa and Sandy lakes, and Plum Coulee, Stephenfield and Rivers reservoirs, following tests by Manitoba government staff, the province said.

“It’s a little out of the ordinary because — for the same reason as the wildfires — it’s been a little short of rain,” Minnedosa Mayor Ken Cameron said. “It’s been quite a few years since we’ve had such a dry spell.”

High levels of nutrients (phosphorus and nitrogen), and warm and calm weather are among the ideal conditions for blue-green algae (cyanobacteria) to develop.

“This year, a prolonged drought period followed by intermittent precipitation events, low flow, low water levels, and warmer temperatures may be contributing factors for bloom formation in Manitoba lakes,” a spokesperson for the province said. “However, a reduction in light availability due to wildfire smoke may be delaying the growth of algae and bloom development in some cases.”

These factors vary across bodies of water, the spokesperson said.

It’s not uncommon for blue-green algae advisories to be issued in Manitoba, Cameron said. Large blooms in sections of Lake Winnipeg have been well-documented in the past.

The provincial spokesperson said the extent of algal growth on Lake Winnipeg remains below the historical 25th percentile for this time of year, as per Environment and Climate Change Canada.

It’s hard to say when Lake Minnedosa’s advisory will be lifted, but provincial officials will continue testing the water, Cameron said.

The advisory shouldn’t discourage people from visiting Minnedosa, he said, as the town prepared to host its annual Rockin’ the Fields music festival from Friday to Sunday.

“Just because the lake’s got some algae in it, there are still a ton of fun things to do in the town of Minnedosa,” he said.

The province said blue-green algae is difficult to predict, and it may disperse quickly or last for several days or weeks.

Blooms form floating clumps or scums, occasionally making water look like thick pea soup or paint. They may emit a strong, unpleasant odour.

Blue-green algae can cause diarrhea, stomach cramps, skin rashes and eye irritation.

Most small water treatment systems used by home or cottage owners are unable to removal algal toxins, while boiling or chlorination will not make the water safe for human consumption, the province said.

Manitoba Environment and Climate Change monitors more than 50 beaches for E. coli, blue-green algae and microcystins, which are toxins produced by blue-green algae. Not all algal blooms produce toxins.

Algae toxin signs are not currently posted at any beaches where regular testing occurs, as per the province’s website.

chris.kitching@freepress.mb.ca