TORONTO -- Urgent action is needed to quell seasonal algae blooms that plague the Great Lakes and pose health risks for nearby communities, said a report released on Wednesday.
Algae blooms are caused by an excess of nutrients such as phosphorus, which can cause algae to grow out of control and partially cover the Great Lakes in blue-green film in the summer months.
The report -- issued by the environmental groups Environmental Defence and Freshwater Future -- outlined steps for reducing nutrient pollution in the Great Lakes.
Author Nancy Goucher said algae blooms can be toxic, contaminating municipal water sources.
"Toxic algal blooms can make water undrinkable and unswimmable. They can suffocate fish and they can cost us a lot of money in terms of reduced property value, lost tourism revenue," she said, adding that blooms can also raise the cost of water treatment for municipalities.
The water system of the Great Lakes and St. Lawrence River together hold nearly 20 per cent of the world's surface fresh water.
In 2011, the largest algae mass on record formed in the Lake Erie's western basin, eventually stretching more than 160 kilometres from Toledo to Cleveland, Ohio.
But algae blooms are an issue in lakes across Canada, prompting water quality warnings throughout the summer.
Goucher's report, titled Clean, Not Green: Tackling Algal Blooms in the Great Lakes, outlined a four-point plan to deal with the issue.
She said the most important recommendation suggests the Ontario government look at economic incentives to encourage farmers to actively reduce the run-off of phosphorus, which washes into the lakes and contributes to algae blooms.
"Without phosphorus algae can't grow," she said, calling it the key ingredient in the recipe for toxic algae.
Goucher added that researchers found one of the major barriers to reducing nutrient pollution was a lack of financial resources for farmers.
The report suggested charging businesses and the public fees for polluting the lakes, and then using the money for clean-up programs.
One bloom on Lake Erie earlier this summer resulted in a temporary ban on water use for some 400,000 residents in parts of Ohio and Michigan.
A state of emergency was declared after tests showed the water was contaminated.
"When you drink contaminated water... it can give you stomach aches, it can cause nausea, it can give you fever," Goucher said, adding that at high doses, the algae toxins can cause acute liver failure.
She said swimming in contaminated water is also unpleasant, possibly causing skin irritation and rashes.
"There's a number of different reasons why we want to make sure algae blooms are not blanketing the Great Lakes," she said.
The head of a citizens group along Lake Erie said in a statement the American water contamination serves as a "wake up call."
"Because we live on a peninsula with Lake Erie as our southern boundary, the lake's health has a major impact on all of us in Windsor and Essex County. It goes without saying that we are all concerned about keeping the lake healthy," said Glenn Stresman of Windsor Essex Community Foundation.
Along with economic incentives to stem phosphorus pollution, the report calls for more investment in science and research, a new policy framework and building "water smart" cities, which would involve regulating storm water run-off.
