Lake Erie will see itself blanketed in algae once again this summer.

According to Raj Bejankiwar, a physical scientist with the International Joint Commission and algae expert, “it will be at least an average size bloom.”

The largest algae bloom ever recorded on Lake Erie came in 2011. Bejankiwar said this year’s likely won’t be as big as that 5,000-square-kilometre blob. By comparison, Prince Edward Island is 5,660 square kilometres in size.

Algae feed on phosphorus from farm and lawn fertilizers and laundry detergent that runs off from fields and sewage treatment plants in the Great Lakes Region.

Heavy rains, like the ones that pummelled Windsor-Essex last week, carry more phosphorus to the lakes more quickly.

“If there is no rain or no downpour, it doesn’t reach the lake,” Bejankiwar said. It seems like we had our fair share of downpours [this spring].”

Algae also need warm water and sunlight to grow.

“The most important thing is the feed itself, the phosphorus,” Bejankiwar said. “We have three more weeks of spring to go. A more formal prediction will be made on the 10th of July.”

Bejankiwar said algae cause several problems. He said it’s particularly damaging to the economy.

“It’s all gooey. It’s a thick green material. You don’t want to swim in it,” he said.

About 73 million tourists visited the Great Lakes in Ontario in 2010, injecting $12.3 billion into the Canadian economy, according to the Tourism Industry Association of Ontario.

Last year, several beaches in Chatham-Kent had to be closed due to algae.

Bejankiwar said algae also affect drinking water.

Approximately 40 million people live around the Great Lakes, which provide drinking water to 30 million people.

Last year, toxins from blobs of algae forced Carroll Township, in Ohio, to tell its 2,000 residents not to drink or use the water coming from their taps. Meanwhile, Toledo spent $3 million US last year to keep Lake Erie’s toxic algae out of the city’s drinking water.

In the U.S. alone, coastal “harmful algae blooms” have been estimated to cost at least $82 million US a year with the majority of costs in public health and commercial fisheries sectors, according to the National Centers for Oceanic Science.

Bejankiwar said some toxins released from algae have been found in Canadian drinking water, but not to a dangerous extent.

Algae can contain the cyanobacterial toxins, which are poisonous. They can attack the liver or the nervous system, while some will only irritate the skin.