Hamilton public health is warning residents to avoid all contact with water near Pier 4 in the city's harbour after discovering a toxic blue-green algae.

In a media release Wednesday, officials suggested the following tips to avoid potential health risks:

The algae, also known as cyanobacteria, forms in shallow, warm, slow-moving water, according to public health.

Temperature fluctuation, high nutrient loads and water mixing are all factors that create an ideal environment for it to grow.

Health officials say algae and aquatic vegetation can start to smell as it dies off and starts decaying when cooler weather arrives, but some local algae blooms have lasted until late November and early December.

The worst effects from the algae come through ingesting water contaminated with it, but the city says Hamilton's drinking water isn't impacted.

People who come into contact with the algae or ingest it may develop a skin irritation, rash, sore throat, red eyes, swollen lips, fever, nausea, vomiting and diarrhea.

Anyone who has been in the water near Pier 4 and is experiencing those symptoms is told to contact their health care provider or a walk-in clinic.

The toxic algae has been regularly detected in the area for years.

The city's website says it "continues to be a big environmental challenge" because there's no way for the city to control or stop the algae from forming near the short or beach.

The city says it has been trying to address it by trying to stop the phosphorus in wastewater and storm water from flowing into the harbour.

Bobby Hristova is a journalist with CBC Hamilton. He reports on all issues, but has a knack for stories that hold people accountable, stories that focus on social issues and investigative journalism. He previously worked for the National Post and CityNews in Toronto. You can contact him at bobby.hristova@cbc.ca.

Audience Relations, CBC P.O. Box 500 Station A Toronto, ON Canada, M5W 1E6

Toll-free (Canada only): 1-866-306-4636

It is a priority for CBC to create a website that is accessible to all Canadians including people with visual, hearing, motor and cognitive challenges.

Closed Captioning and Described Video is available for many CBC shows offered on CBC Gem.