He's spent decades around Lake Winnipeg, but filming a recent documentary sent Paul Kemp into green sludge to investigate.
Kemp, president of Stornoway Productions and producer of the 44-minute film Save My Lake, was at a public forum Tuesday about the scourge of blue-green algae.
Kemp shot the film from March to December 2010, and it aired in 2011 on CBC's The Nature of Things.
"I've been going there since I was a little kid, so over 40 years now, I've been a cottager, and I gradually recognized that there was things going wrong, there were more algae blooms coming, the erosion on the beaches was occurring, the marshes seemed to be becoming a monoculture," said Kemp, who grew up in Winnipeg and is now based in Toronto, but returns to his cottage in Manitoba.
Kemp, and Allan Casey, author of Lakeland: Ballad of a Freshwater Country, spoke to about 90 people at the forum.
"Canada's a lake country that doesn't know it's a lake country," said Casey. "We're all working toward building that awareness here."
His book won the Governor General's Literary Award for Nonfiction in 2010.
The event was organized by Living Lakes Canada and the Lake Winnipeg Foundation.
"What we've found is that Lake Winnipeg is the most highly chlorophyll-laden lake of its size in the world," said Kemp, adding that finding comes from the Lake Winnipeg Foundation and Ducks Unlimited.
Kemp said 544,000 bags of lawn fertilizer -- or the equivalent -- end up in the lake every year.
"When fertilizer goes in, phosphorus goes in," he said.
"Phosphorus is what's called an accelerant... if you put phosphorus on your plants in your front yard, your plants will grow, if you pour it in the lake, algae uses it and it starts to explode."
He referred to "green guck" swamping beaches and the danger of algae blooms.
"The algae gets so thick that it actually can go toxic... it can create toxins that can be quite harmful to dogs if they drink it," said Kemp.
He also said decomposing algae blooms can start "gobbling up the oxygen in the lake."
"The fear is that you have enough algae blooms that die and start to decompose, the oxygen in the lake gets swallowed up and then you can have massive fish kills," he said.
"Lake Winnipeg is probably one of the highest-risk lakes for becoming a dead zone," he added.
It has a 1,000,000-square-kilometre drainage zone, he said, so "if you flush your toilet in Banff, it eventually gets to Lake Winnipeg."
"What I hope people recognize is that we have to stop adding to the problem of phosphorus and excess nitrogen... getting into the rivers, creeks and water systems, at source, so we can stop it before it even gets to the lake," Kemp said.