Already blue-green algae in 16 lakes in Nova Scotia

The county’s Environment and Climate Change Department says 16 lakes have been identified poisonous blue-green algae so far this year, with all reports in June.

At the same point last year, only eight lakes had been identified as having an algal bloom.

Elizabeth Kennedy, the director of the department’s water department, said while there may be more cases this year due to the hot and dry weather in May and June, the department has also pushed through its awareness campaign so more people can report sightings.

“We’ve really promoted people looking for it, so people are watching and much more aware and reporting it to us,” Kennedy said.

There is also a research group at Dalhousie University that studies the algae and is actively looking for it, so there have been some reports from them as well.

The algae releases a toxin that can cause a variety of symptoms in humans, but can also kill a pet in minutes. water.

The department does not monitor the province’s lakes for the algae. All reports are from the public or municipalities in the case of public parks or patrolled beaches.

The blooms could be caused by a number of things, it seems.

“Worldwide, they are still researching why blue-green algae grow in certain places, how they get there, what encourages them to grow and what causes them to release toxins,” Kennedy said. “That’s an active, inconclusive part of research right now.

In general, while the trends seem to show that heat and standing water, followed by a tidal wave during heavy rainfall, “appear to be excellent conditions to bring about a bloom. Blue-green algae may be spreading, or maybe it’s just doing better in the kind of extreme weather events and storms we’re getting more and more because of climate change.”

She said the runoff is believed to contribute to the bloom by pushing up the water at the bottom of a lake where the algae has settled, washing larger amounts of natural sediment and detritus into the water, along lake shores or by fertilizers used by inhabitants of populated lakes. or the disturbance of the bottom during the construction of lakes that can send more sediment into the water.

What makes a bloom disappear “is the million-dollar question,” Kennedy said. “Of course things in the water have their life cycle and a flower can form and disappear or travel around the watercourse and not form a big flower, just do its job.”

Different methods and technologies have been tried in different areas to completely remove the algae, with mixed results.

“I don’t think anything has been the silver bullet,” Kennedy said. “It just depends on the circumstances.”

The lakes where the algae were detected this year are

• Yarmouth County: Lake Ogden and Lake Fanning
• Halifax County: Loon Lake, Three Mile Lake, First Lake, Second Lake, Kinsac Lake, Shubenacadie Grand Lake, Wrights Lake, Oathill Lake
• Kings County: Aylesford Lake, Armstrong Lake, Lake Torment
• Hants County: Lake Martha
• Queens County: Molega Lake
• Lunenburg County: Covey Lake