Fighting blue-green algae

An expert on blue-green algae said a City of Greater Sudbury bylaw restricting the use of fertilizer containing phosphorus if a good start towards preventing blue-green algae blooms from forming in the city's lakes.

However, there is more the city could do to combat this problem, according to David Schindler, a University of Alberta biologist who spoke at a Dec. 7 forum at Science North organized by the Greater Sudbury Watershed Alliance.

Schindler explained that high-phosphorus runoff stimulates the growth of blue-green algae.

Blue-green algae, or cynanobacteria, are primitive, microscopic plants that live in fresh water, according to an information sheet from the province.

Although many forms of blue-green algae are harmless, some forms produce toxins which can be harmful to your health.

Nine of the 32 blue-green algae blooms reported in the province in 2011 were in Sudbury.

The fertilizer bylaw, the first to be passed in the province, comes into effect in April 2012.

The city also plans to upgrade the Kelly Lake Road sewage treatment plant. Schindler said this will also help prevent blue-green algae from showing up in local lakes, as sewage contains phosphorus.

He also suggests designing streets differently so that water seeps onto lawns and into wetlands instead of draining into the sewer system.

“This is so the terrestrial plants that you want to grow get the fertilizer rather than aquatic plants,” Schindler said.

Sudbury is prone to blue-green algae blooms because the city has “all these little lakes embedded around the city” which are vulnerable to high-phosphorus runoff, he said.

“Other cities that have that, like Madison and Minneapolis, have had this problem develop,” Schindler said.

Local scientists should study the issue to track down the biggest sources of phosphorus runoff, he said.

In Alberta, where Schindler works, there are 84 million head of cattle which produce phosphorus through their excrement.

“It's like having 84 million virtual humans,” he said. “The three million humans in Alberta get very good sewage treatment where the phosphorus is removed. But there's 84 million virtual humans who can just crap anywhere. It's kind of a bizarre situation.”

Schindler first started studying blue-green algae more than 40 years ago when he headed up the experimental lakes project with the Fisheries Research Board of Canada.

At the time, the detergent industry was trying to deny that phosphorus caused blue-green algae, because they didn't want to change their detergent formulations, he said.

Schindler and his colleagues added phosphorus to several small lakes in northwestern Ontario, and blue-green algae immediately appeared. Phosphorus was removed from detergents in the early 1970s.

The forum featured several other speakers, including Laurentian University biology master's student Jaimee Bradley.

For the past two years, she has been studying the causes of blue-green algae in Ramsey Lake.

In the early 1960s, Ramsey Lake had widespread blue-green algae blooms, she said. In recent times, however, the first blue-green algae bloom was reported in Ramsey Lake in 2008.

Bradley said there is a lot of phosphorus already in the lake, and this is part of the problem. However, streams and lakes which empty into Ramsey Lake are constantly pouring more phosphorus in.

By monitoring these streams and lakes, she determined that Frobisher Creek, which flows through an urban part of the city, has the highest levels of phosphorus.

After one heavy rainfall, she recorded 400 millimetres of phosphorus per second flowing into Ramsey Lake from Frobisher Creek.

“That is a lot of phosphorus,” Bradley said. “Frobisher Creek should be continually monitored or at least monitored further, and possibly have some sort of storm water containment area or something along those lines.”

Heat and calm wind conditions also cause blue-green algae to form, she said.

In the days before a blue-green algae bloom which caused the Ramsey Lake beaches to be closed was sighted Aug. 31, 2010, the city was in the midst of the heat wave, and there was little wind, she said.

Stephen Butcher, president of the Greater Sudbury Watershed Alliance, a group made up of 19 lake stewardship groups within the city, said blue-green algae is of great concern to his members.

Most of them are among the 25,000 city residents who do not use municipally-treated water, he said.

Although he said he's happy Bradley is studying Ramsey Lake, he said all of the major lakes in the Greater Sudbury area should also be studied.

Butcher said he's concerned about septic bed systems, as they're prone to failing, along with less-advanced municipal sewage systems, as there's leakage from these facilities. Both result in higher phosphorus levels in lakes, he said.

“On Long Lake along, there 12,000 individual field beds, and in the city, there's closer to 12,000,” he said.

“Field beds, at the present time, are not inspected except when they're first built. All over the province, other communities are reinspecting the beds. They're finding a 28 per cent failure rate on these field beds.”

Posted by Heidi Ulrichsen