Toxic algae is back in Hamilton Harbour, and health officials want you and your pets to stay away from it.

“We’re seeing it at Bayfront Park and Pier 4 Park,” said Robert Hart, manager of the city’s health protection division, yesterday.

Blue-green algae — also known as cyanobacteria or pond scum — is a species of algae that grows quickly in shallow, slow-moving waters under very warm conditions.

Cyanobacteria blooms occur regularly and are not a new phenomenon. Last year, public health detected the toxic algae on Aug. 7.

“They have this green paint look, a vibrant green,” Hart said. “The algae blooms can last for a week or two,” and continue to contaminate the water even when the algae bloom is no longer visible.

Cyanobacteria produce a toxin that can make people and animals ill through skin contact or ingestion.

It can cause headaches, fever, diarrhea, abdominal pain, nausea and vomiting, as well as cause skin rashes and mucous membrane irritation.

While there have been no reports of cyanobacteria poisoning, public health says people and pets should avoid swimming or wading near the shoreline in Hamilton Harbour. Public health has posted warning signs along the Hamilton Harbour Waterfront Trail from the Desjardins Canal fishing area to the Pier 4 Park beach area.

People should not eat any fish caught in the harbour, health officials say.

“If you do get some on you or your pet goes into the water, wash it off while wearing gloves as soon as possible,” Hart said.

“If you experience any symptoms, you should see your doctor.”

Hamilton’s drinking water is not affected by the blue-green algae, which is being monitored by public works.

via TheSpec.com – Local – Algae warning issued.