Blue-green algae bloom ‘resolved’, beach advisories lifted in Innisfil

You can swim safely again along the shores of Lake Simcoe in Innisfil.

The Simcoe Muskoka District Health Unit confirmed on July 22 that the blue-green algae bloom affecting the southeast shore of Kempenfelt Bay (Bear Point area) and the southwest shore of Lake Simcoe (Innisfil Beach Park area) was “resolved”.

The bloom is why swim advisories were posted for the first time at four city beaches – Innisfil Beach Park North and South (676 Innisfil Beach Rd.), Leonard’s (2715 Purvis St.) and Bon Secours (2407 Leonard St.) – almost two weeks ago. With Monday’s news, those warnings were lifted.

Technically known as cyanobacteria, this algae is made up of microscopic organisms that occur naturally in lakes and streams. They are usually present in small numbers, but can grow quickly and form dense blooms when the water is warm, slow moving and full of nutrients such as nitrogen and phosphorus.

“Many species of blue-green algae have the potential to produce toxins that are harmful to human and animal health,” the health facility says. “Symptoms following contact with or consumption of toxins from a blue-green algae bloom may include skin, eye, nose, throat or lung irritation, stomach pain, headache, diarrhea, vomiting and, in severe cases, liver damage . Symptoms may be worse if water is swallowed in large quantities. If you suspect a blue-green algae bloom, use caution and assume toxins are present to avoid exposure.”

The bloom also sparked a difficult exchange of written words between local watershed advocates and Barrie-Innisfil MLA Andrea Khanjin, who is also Ontario’s Minister of Environment, Conservation and Parks.

“Lake Simcoe is experiencing a record number of beach closures and blue-green algae outbreaks. Significant parts of southern Ontario have been flooded this week,” Lake Simcoe Rescue Coalition executive director Claire Malcolmson wrote in a letter to the editor published by InnisfilToday July 19. “Deputies usually comment on such things. We hear crickets.”

But Khajin insisted in his own letter released hours earlier that the province is taking steps to reduce nutrient concentrations and improve the lake’s health.

“Although there is much more work to do, our efforts are already showing positive results,” she said. “Some signs of recovery in the Lake Simcoe watershed include a 50 percent reduction in phosphorus from sewage treatment plants entering the watershed, decreased algae in the lake, and successful reproduction of cold-water fish such as brown trout. lake, lake fish and cisco. . We will continue to build on our progress and adapt our approach over time to ensure that Lake Simcoe can be enjoyed by generations to come.”

Anyone who sees a potential bloom is encouraged to report it to the ministry’s Parks Spill Action Center online or by phone at 1-866-663-8477.