September 01, 2006

• Algae blooms were observed at West Grand Beach and Victoria Beach on Lake Winnipeg on Aug. 29. The concentration of an algae toxin, microcystin-LR, was below Manitoba’s proposed recreational water quality guideline of 16 micrograms per litre.

• One of the most important things to think about when enjoying Manitoba’s beaches is safety. When taking a group of children to the beach, be aware of each person’s swimming abilities and divide the group into smaller groups for easier supervision.

• The volume of Lake Winnipeg is 284 cubic kilometres (one km wide by one km deep by one km long), equivalent to more that six billion times the volume of a standard 14-by-28-foot backyard pool.

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• Extensive sampling for E. coli in beach sand and water on Lake Winnipeg is underway again this year and follows from the work done in 2003, 2004 and 2005.
• Research has shown that wet sand underlying a number of Lake Winnipeg beaches contains E. coli bacteria that can be washed into beach water when water levels rise and flood beaches.
• Advanced testing known as DNA ribotyping is being used to identify sources of contamination. Results over the last several years indicate that approximately 50 per cent of the sand and water samples could be attributed to shorebirds and geese, while 36 per cent of the samples could not be matched to a source. Only seven per cent of the samples could be attributed to humans.
• Advisory signs were posted at Grindstone and Matlock beaches on Aug. 23, at Gull Harbour and Sandy Hook beaches on Aug. 16, at Gimli Beach on July 30, at Oak Lake, Pelican Lake (South Beach) and Lynch’s Point on July 29, at West Grand Beach on July 1, at Winnipeg Beach on June 28, at East Grand Beach on June 7, and at Hnausa, Spruce Sands and Sandy Bar beaches on June 2.
• Although the risk of illness is small, advisory signs help to remind bathers of additional precautions they can follow to reduce the risk of bather-related illness at beaches where E. coli levels fluctuate regularly. Since bacteria levels can fluctuate at these beaches, the advisory signs will remain posted for the duration of the summer.

• Algae are a sign of a healthy lake since they provide food and oxygen for many aquatic life forms. However, too much algae will form floating clumps or scums and can cause water quality problems for drinking water and recreation. During bloom conditions, the water sometimes looks like thick pea soup and may emit a strong, unpleasant odour.
• Although algal blooms are not uncommon in Lake Winnipeg, periods of calm, warm and sunny weather tend to increase the intensity and frequency of algae blooms. In addition, during the summer of 2005, heavy rainfall in Manitoba lead to high volumes of water in the Red and Saskatchewan rivers bringing larger than average loads of nitrogen and phosphorus into Lake Winnipeg. Nitrogen and phosphorus transported into Lake Winnipeg in 2005 remain in the lake and are available to support algae growth during 2006. While the formation of algae blooms is difficult to predict, warm and calm weather coupled with relatively high nutrient loads presents ideal conditions for their development.

• The following beach hygiene tips will help keep Manitoba beaches clean:

• Most swimmers will not become ill when E. coli bacteria levels are elevated above the recreational water quality guideline. However, the possibility of illness increases with rising levels of bacteria.
• Manitobans can safely enjoy the province’s plentiful beaches and are advised to keep a few things in mind when at the beach:

• Algae blooms can produce toxins that can be harmful to the liver or nervous system if large amounts of water are ingested. Drinking water containing algae can also cause an upset stomach and diarrhea, and external exposure to algae blooms has been reported to cause skin irritation.
• In the absence of a severe algal bloom, recreational activities are considered safe. However, if large amounts of green scum are visible in the water, it is advisable to: