News Releases

Western shoreline of Hamilton Harbour confirmed to have blue-green algae

HAMILTON, ON - Public Health Services has confirmed the presence of toxin-producing blue-green algae (cyanobacteria) at the Bayfront Park Boat Launch, Pier 4,  Harbour West Marina, and throughout the marinas on Macassa Bay.

Contact with blue-green algae should be avoided due to the potential health risks associated with it. Residents and visitors are advised to:

  • Avoid all contact with the water along the western shoreline of Hamilton Harbour, including while launching or trailering watercraft.
  • If you do come in contact with the water, wash yourself off as soon as possible with clean water. Facilities for hand washing and rinsing off are available at the Bayfront Park Public Washrooms located at the east side of the Bayfront Park parking lot.
  • Do not swim or wade (or allow your pets to swim or wade) in any areas where blue-green algae (cyanobacteria) is visible.

Health Effects

Adverse health effects are mainly caused by drinking the water that is contaminated with blue-green algae toxins. People who come into contact with 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.

Anyone who has recently been in direct contact with the waters along the western shoreline of Hamilton Harbour and is experiencing headaches, fever, diarrhea, abdominal pain, nausea or vomiting is advised to contact their primary care provider (family physician, nurse practitioner or walk-in clinic).

Quick Facts

  • Blue-green algae (cyanobacteria) forms in shallow, warm, slow-moving or still waters.
  • Temperature fluctuations (i.e. increased water temperature), high nutrient loads, water mixing, slow-moving or still waters, provide the ideal environment for the proliferation of naturally occurring blue-green algae.
  • Algae/vegetation in the water can give off an offensive odour as it dies and decays. This may be more prominent along the shoreline and in the various “nooks and crannies” (i.e. docks/boat slips).
  • The blue-green algae is expected to subside as the cooler weather arrives. Locally, algae blooms have been observed until late November, early December.
  • The safety of Hamilton’s drinking water is not affected by this situation.

Additional Resources