INDIAN HARBOUR LAKE — The Municipality of the District of St. Mary’s is advising residents and visitors to avoid contact with Indian Harbour Lake after what it describes as the confirmed presence of blue-green algae (cyanobacteria).
The advisory, issued July 16, is based on a listing for Indian Harbour Lake – “bloom as of June 2025” – posted on the provincial Department of Environment and Climate Change’s blue-green algae website.
The municipality notes that Indian Harbour Lake is the only site in the district listed by the province as having a blue-green algae bloom. However, the provincial website states these listings are based on potential sightings reported by the public or municipalities, and do not represent confirmation by provincial inspectors or laboratory analysis.
As of press time, there has been no official confirmation by provincial authorities of a blue-green algae bloom at Indian Harbour Lake or elsewhere in the municipality. The Department of Environment and Climate Change notes that in the case of public drinking water supplies, an inspector visually confirms the presence of blue-green algae, but for recreational water bodies, reports are published to help residents make informed decisions about water use.
According to the province’s latest list, two other local area lakes are also reported as potential blue-green algae sites: Grant Lake near Mulgrave and Lochaber Lake in Antigonish County, both listed in June 2025.
Blue-green algae can pose health risks even if not laboratory confirmed. The provincial department warns that contact with or ingestion of water suspected to contain blue-green algae may cause skin, eye, or throat irritation, as well as symptoms like nausea or vomiting. Pets and small children are especially at risk. The department recommends avoiding contact with the water, not drinking or bathing in it, and keeping pets and livestock away as a precaution.
Blue-green algae blooms may look like a film, scum, or paint-like layer on the water and can be blue-green, green, brown, red, white, or mixed in colour. They may also resemble pea soup, grass clippings, or clumps of debris.
St. Mary’s will continue to monitor the situation and provide updates as necessary. Residents are encouraged to visit the provincial website (novascotia.ca/blue-green-algae) for the most current list of reported potential sightings and to follow all safety recommendations.
Anyone who thinks they see blue-green algae is asked to report it to the Department of Environment and Climate Change at 1-877-936-8476.
The Journal is seeking further comment from the department and will update readers as more information becomes available.
