Past blue-green algae blooms in Halifax have not been dangerous to humans, research finds

Blue-green algae may put a damper on beach plans in Halifax, but recent research from Dalhousie University indicates that the risk to swimmers has been minimal in recent years. A team of researchers monitored eight recreational beaches over a three-year period and found that while the genes for blue-green algae were present at each site, the toxins detected were well below Health Canada’s acceptable levels for water toxins.

Elizabeth Montgomery, a water resource specialist for the municipality’s environment and climate change team, expressed optimism about the findings. She noted that even in areas where blue-green algae blooms were present, the toxin levels were not considered a risk to swimmers. This is reassuring news for beachgoers, especially considering the frequent closures of Cunard Pond due to blue-green algae in recent years.

Blue-green algae can be found in bodies of water throughout Nova Scotia and has the potential to produce toxins harmful to both humans and pets. To address this issue, all supervised beaches in the Halifax Regional Municipality are monitored for blue-green algae from July 1 to August 31. If algae is detected, the beach is closed until further testing can be completed.

Montgomery emphasized the importance of proactive monitoring and quick decision-making when it comes to beach closures and reopenings. The research conducted by Dalhousie University provides valuable insights that can help expedite this process and ensure the safety of beachgoers.

While the risk to humans may be limited, Montgomery cautioned pet owners to be vigilant, as dogs are more susceptible to harm from blue-green algae mats that can wash up on shore. Ingesting these mats can be fatal to pets, as tragically demonstrated by the deaths of two dogs at Shubenacadie-Grand Lake in 2021.

To ensure a safe swimming experience, Montgomery recommended visiting HRM’s supervised beaches, where water quality is regularly tested. By following these precautions and avoiding drinking lake water, swimmers can enjoy a worry-free day at the beach.