Tips for staying safe against blue-green algae this summer

With temperatures rising, many shutdowns due to the toxic blue-green algae has made for a tough time finding a safe spot to swim in the region – with one of the most recent shutdowns at Cunard Pond Beach in Halifax.

Elizabeth Montgomery, a water resource specialist with the Halifax Regional Municipality, said what we’ve come to know as blue-green algae isn’t actually algae at all; it’s a bacteria called cyanobacteria.

“It’s naturally occurring in our water bodies here, but when the conditions are right, the water temperatures are right, when there’s enough nutrients for blue-green algae to eat, it can form what would be called blooms which is what we’re seeing at Cunard Pond Beach right now,” said Montgomery in an interview with CTV’s Ana Almeida on Friday.

Montgomery said the blooms are dangerous as they are toxic, and to avoid the water if you see signs of them.

“What you’re looking for when you’re looking for a bloom is that classic kind of green water I’m sure folks are thinking of. It can also look like spilled paint, grass clippings, or in some cases an oil slick. If you see something in the water you’re not sure it’s just best to stay out,” she said.

Blue-green algae tends to appear throughout the summer due to the hot weather, but Montgomery said it’s actually almost always in the water, we just can’t see it.

“It needs to be a certain water temperature, warm enough basically, for these blooms to grow big. So the blue-green algae is in the water all the time but just not at a concentration where we’re really seeing toxins at all,” she said.

Montgomery said the municipality keeps a close eye on their 19 supervised beaches, and they have a zero-tolerance policy when it comes to blue-green algae.

“When we see something and we’re not sure that it isn’t toxin producing, which is what happened in this case, we close the beach just as a precaution and then we send it for testing to see if there are toxin-producing species there,” she said.

“If there are, we keep the beach closed until the bloom has dissipated and we’re able to test and make sure that the toxic concentration in the water is low.”

While the main risks are associated with consuming that water that has blue-green algae in it, Montgomery said contact with someone’s skin can be enough for damage to be done.

“Typically what we’re seeing in HRM is the size of the blooms that we’re seeing, you definitely should get out of the water if you find yourself swimming surrounded by a bloom, but unless you’ve consumed some of the water, your risks are typically, not always, but typically will only be skin symptoms like rash itchiness, redness, maybe hives,” she said.

“If you’ve swallowed the water in large concentrations you may also see gastro symptoms, and if that’s the case then you certainly should seek medical help,”

Montgomery said the deaths of dogs that has been seen around the region in recent years was due to a different type of mat-forming blue-green algae.

“That’s a different kind of blue-green algae. The dogs that have died unfortunately have eaten that blue-green algae and it has a much more potent toxin in it, but it isn’t from swallowing water,” she said.

“Mats we also tend to see those form in early May and depending where they are they can persist throughout the summer as well.” 

Anyone who sees an algae bloom at an unsupervised beach can contact the province to report it.

With files from CTV's Ana Almeida.