Shuniah, Ont. — Though blue-green algae isn’t usually a scourge associated with Lake Superior, last week’s confirmed sighting of a bloom on the shores of Shuniah wasn’t the first time one has been spotted on the big lake.
According to Ontario’s Ministry of Environment, Conservation and Parks, the toxic slime appeared on the Ontario side of what’s sometimes called an inland sea as early as 2021.
Though the ministry says it takes concerns about blue-green algae “very seriously” and continues to collect samples and conduct lab tests, it’s not yet clear why blooms have started to show up in Superior, traditionally one of the coldest fresh-water lakes in the world.
Sightings have also been made in recent years on Lake Superior’s American side.
Kait Reinl, a Wisconsin-based scientist who specializes in water quality issues, earlier told a Milwaukee newspaper that the appearance of blooms may be a “signal” that Lake Superior is undergoing change.
On Monday, the National Centres for Coastal Ocean Sciences, which is based in Silver Spring, Md., announced a $7.5-million plan to “fund, research and develop commercially viable technologies to control” harmful algae blooms.
Harmful “blooms are a growing concern across the U.S., as they not only threaten animal and human health but also present serious economic threats to fishing, tourism, and other industries by making water unsafe,” the agency said.
Algae usually thrives in warm water bodies that are overburdened with phosphorous from household appliances, like dishwashers, or nutrients that run off from farms and septic fields. Lake Erie has been a classic case.
Last week’s confirmed sighting on Lake Superior was on a bay in the area of Shuniah’s Scott Drive and Birch Beach Road.
“There are several homes in this area with lakefront properties where people can swim,” Thunder Bay District Public Health Unit inspector Matt Bradica said on Monday.
When blooms appear, the health unit recommends that people refrain from drinking, swimming or fishing in the vicinity until two weeks after blooms have disappeared.
In Shuniah, homeowners draw drinking water from Lake Superior or a well. All property owners have their own septic systems, which must be approved by the province.
Blue-green algae blooms have also become more common on Thunder Bay-area inland lakes.
Last month, a bloom was confirmed on Icarus Lake, which is located about 100 kilometres southeast of the city off Highway 588 near Northern Lights Lake.
A similar bloom was spotted at the end of June on Trout Lake, about 30 kilometres north of Thunder Bay in Gorham-Ware Township.
During the hot summer of 2021, the health unit issued eight warnings for blue-green algae across the Thunder Bay district, the most ever in a single season.
Meanwhile, Ontario’s Environment ministry says lakefront property owners can reduce their phosphorous output in a number of ways.
Pro-active measures include “using phosphate-free detergents, not bathing in lakes, maintaining naturalized shorelines, not using fertilizers . . . and ensuring that septic systems don’t leak or discharge into water bodies,” a ministry bulletin says.