08-08-2025
Pier 4 Park Beach closed after blue-green algae confirmed in the water, city says
The City of Hamilton has closed the Pier 4 Park Beach due to confirmed blue-green algae.
The city said in a news release on Friday, finding the toxin-producing algae at Pier 4 "serves as a strong indicator that blue-green algae can be present within the broader watershed."
People and pets should avoid all contact with the water at the Pier 4 Park Beach shoreline, the city said. The city also recommends washing with clean water immediately if someone comes in contact with the beach water at Pier 4.
"People who come into contact with the visible blue-green algae or ingest water containing blue-green algae may experience skin irritation, rash, sore throat, sore red eyes, swollen lips, fever, nausea and vomiting and/or diarrhea," said the city in the news release.
If anyone has come in contact with the water recently and is experiencing symptoms like headaches, fever, diarrhea, abdominal pain, nausea or vomiting, should contact their primary care provider.
A McMaster University water scientist told CBC Hamilton last year "a small dog could be killed" if it drank water with blue-green algae.
"Do not let a dog off-leash near a water body that has blue-green algal blooms because the microcystin toxin is deadly," said Gail Krantzberg, a water scientist and professor in the university's masters of engineering and public policy program.
The city also said signs will be posted at the park advising the closure, which will be in effect until the blue-green algae subsides.
The algae grows in slow-moving or still shallow, warm water and can produce an "offensive" smell as it decays, the city said.
In December, city staff presented preliminary research into ways to help mitigate blue-green algae blooms after it caused putrid smells for several weeks last summer.
The report recommends testing out several "experimental treatments" — like circulating the water, introducing aquatic plants that absorb nutrients and limit sun exposure, and skimming the blooms off the surface — to help prevent or remove the rotting mats of algae but cautioned residents this is not the type of problem with a quick fix.
