Halifax Regional Municipality (HRM) has put up a warning sign to beach goers about the presence of blue green algae in the water at Oakfield Provincial Park. “When we are talking about blue green algae it can be a whole category of organisms. And so, they are photo synthesizing bacteria that live in lakes and sometimes when conditions are good for them, they form mats on the bottom of lakes and blooms that can sometimes be toxic,” says Elizabeth Montgomery, HRM Environment and climate water resources specialist. According to Montgomery, the municipality has been noticing the blooms blow in during the morning when the water is calm. “There aren’t visual indicators that just an average person would see, because we know we have some locations where we are seeing these blooms more frequently. Another thing that’s challenging about these is you can’t tell by looking at it if they are toxic even if you are an expert,” she says. Montgomery says there are mats and blooms – mats lay on the bottom of a water course and release quite significant toxins. “But only in the mat itself. All the research we have seen is, even if there are lethal amounts of toxins in the mat itself, in the water above it it seems to be little or non detectable,” she says. Oakfield Provincial Park is the first HRM beach to close due to blue green algae this year. “As far as a bloom, in the toxin concentrations that we are seeing, they are not reaching the drinking concentration guideline when we are monitoring which is good news. The largest risk to people and dogs is really skin rash, skin symptoms, itchiness, hives. If you find yourself in a bloom or really anytime you’re swimming in nature, just towel yourself off vigorously and take a shower when you get home,” says Montgomery. She adds people should not let their pets drink the lake water. “There are a lot of other pathogens in the water as well, it’s not treated and lots of animals are living there,” says Montgomery. Professor Tri Nguyen-Quang has been researching the bacteria for around 14 years around Maritime waters. He says he’s noticed blue green algae is more prevalent in waters around Nova Scotia and New Brunswick. “The pigment has to firstly be analysed in the lab, and the second direction that we are taking with the monitoring is using the drone and we fly over the lakes and take some pictures and we analyse the information from the pictures we combine with analysis from the lab,” says Nguyen- Quang. He currently has four students working on this research with him – two graduate students and two second year students. So far, they have learned a lot about the blooms as well as ways to prevent them. Climate change, Nguyen-Quang says, is one reason why more blooms are forming. “We can prevent the situation by not using lots of fertilizer and pesticides and waste into the water body. Try to use phosphorus free detergent as well and for boating and kayaking in the summer, not to contaminate other lakes after using a boat or kayak in one place. You have to clean them before you put them in the lake,” says Nguyen-Quang. He says not all blue green algae are toxic, but to be sure they need to be tested by an expert. Nguyen-Quang adds the peak of the blue green algae season is August, but the season could last until September, October and even November. For more Nova Scotia news, visit our dedicated provincial page
