Cyanobacteria once again lead to beach closures around Massawippi lake

By Anne Sophie Le Brun Robles Gil Special to The Record

On July 22 a warning was issued about cyanobacteria near Massawippi beach and North Hatley beach. Conditions improved the following day and swimming was again permitted at the beach, but it was recommended swimmers not remain in the water for extended periods.
Present in the Massawippi lake since at least 2006, cyanobacteria have been the cause of several beach closures like the recent one. And for good reason, too. Cyanobacteria can be quite toxic.
So, what exactly are cyanobacteria? Well, they are commonly known as blue-green algae, although this is a misnomer because they aren’t technically algae. Instead, they are an ancient group of bacteria that date back at least 2.5 billion years. In fact, they are amongst the first living things to leave a significant fossil record. These bacteria are a little different from the ones that make you sick or help you digest your food as part of your gut flora: they can do photosynthesis. This is why they were mistaken for algae for such a long time.
They are amongst the first living things to have done photosynthesis and are credited for having created a significant portion of the 21 per cent of oxygen found in our atmosphere. Even today, cyanobacteria are responsible for 20 to 30 per cent of the photosynthesis that happens in open water. Cyanobacteria are also an important component of plankton, which are microscopic organisms at the base of most aquatic food webs. In their absence, the food web would collapse.
But, what about the toxicity? For all the good they do on a global scale, they can be dangerous on a local level when they bloom.
Cyanobacteria can create a variety of different toxins, like neurotoxins that damage the nerves and hepatotoxins that damage the liver. The tricky thing is that not all species of cyanobacteria produce toxins, and the only way to know for sure is to send a sample to a lab. Even then, it can take a week or more before you get the results back. By that point, lots of people and animals may have been exposed to the toxins, which are a serious health concern.
These toxins can cause symptoms like vomiting, diarrhea, disorientation, seizures, skin irritation, and breathing difficulties in as little as 15 minutes after exposure. Other times, it will take a few days before symptoms start to show up. In serious cases, these toxins can even be fatal.
This is especially a problem with dogs. Dogs tend to drink the lake water or lick it off their fur after a swim, meaning they end up ingesting more toxins.
What should you do if you think you, someone you know, or your dog has been exposed? The first thing is to rinse any lake water off with clean water to make sure no more toxins get into their system. Next, you should call a doctor or a vet.
Of course, it would be better not to be exposed to these toxins. Seeing as it is hard to know when cyanobacteria are toxic and when they aren’t, it important to avoid the water if cyanobacteria are present.
How can you tell if there are cyanobacteria in the water, then? Usually, cyanobacteria take one of two forms, both of which can be dangerous. Either they grow in very algae-like mats at the surface or spread out deeper in the water, where they will turn the water an opaque blue or green colour. Cyanobacteria may even be brown or red.
If you see cyanobacteria, make sure no one goes into the water, dogs included. Then, if a municipality or conservation organization has not yet issued a warning about the cyanobacteria in that area, contact them to let them know. They will then be able to dispatch someone to come to check it out, confirm the presence of cyanobacteria, and issue an official warning.
Would it not be better still to have fewer cyanobacteria blooms in our lakes?
Yes, within reason, but two of the main factors leading to more cyanobacteria blooms can be difficult to control. The first of these factors is heat. The hotter it is, the more cyanobacteria grow. With climate change leading to warmer and warmer summers, the situation may get worse. The second one is nutrients. Cyanobacteria grow better and faster when there are lots of nutrients in the water. These nutrients can come from fertilizer runoff from farms. Having better protections in place to keep fertilizer from getting into the lakes could be a great help.

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