Blue-green algae is back

Pools of blue-green algae are back in Hamilton Harbour — a little later in the season than normal.

But they’re still prompting warnings from the city’s health department for people and pets to avoid contact with it. Here’s what you need to know about blue-green algae.

Q. Where is it a problem?

A. The main areas are Bayfront Park boat launch, Pier 4 Park beach, Harbour West Marina and throughout the marinas on Macassa Bay.

Q. Where does the algae come from?

A. The algae has always been around in Hamilton Harbour, but in 1999 Environment Canada scientists at the Canada Centre for Inland Waters started noticing it in much higher concentrations, making sections of the bay look like pea soup.

Virtually every year since then, the harbour has been struck with by an outbreak at some point in the midsummer, with the algae lasting until early winter.

Q. How bad has this summer been so far?

A. This year, the harbour is experiencing an average amount of algae, the health department says.

Q. What can be done about it?

A. The algae feeds on phosphorus and ammonia from sewage treatment plant discharges, and urban and farm run-off. By controlling those discharges, it will lower the amount of blue-green algae, scientists believe.

Q. What are the health concerns?

A. Public health says contact with blue-green algae should be avoided. Contact can cause skin irritation, rashes and itching. Larger exposures can cause headaches, fever, diarrhea, abdominal pain, nausea or vomiting, and mucous membrane irritation. People who have been exposed to the algae and suffering symptoms are advised to seek medical attention.

For further information:

For information about local beaches:

905-526-4687 | @Markatthespec

905-526-4687 | @Markatthespec