If you have the urge to swim or wade in the western end of Hamilton Harbour right now, don’t. There’s blue-green algae there.

That’s the advice of Hamilton Public Health Services, which is telling people to avoid swimming or wading near the shoreline and in shallow calm areas of water. This is particularly true when there’s a noticeable green surface scum or discoloration.

“Residents are advised not to eat fish caught in these areas and not to let children or pets come into contact or drink from the water,” said Matthew Hodge, Hamilton’s associate medical officer of health.

“Blue-green algae can be present in the water even in the absence of a visible scum. And not all surface scums are toxic since they can be caused by other, non-toxic algae.”

Public Health has detected blue-green algae toxins at the western shoreline of Bayfront Beach in Hamilton Harbour and at the nearby Bayfront Park boat launch.

Algae blooms may also be at other recreational water access locations in the harbour.

Public health advises the following:

  • Some blue-green algae can produce toxins or skin irritants.
  • Drinking water contaminated with blue-green algae can cause adverse health effects.
  • Skin contact with contaminated water can cause skin irritation and itching.
  • Exposure to blue-green algae toxins, if present in sufficient amounts, can cause headaches, fever, diarrhea, abdominal pain, nausea or vomiting, skin rashes and mucous membrane irritation.

Anyone who’s come into direct contact with water in west Hamilton Harbour who’s experiencing headaches, fever, diarrhea, abdominal pain, nausea or vomiting should contact their doctor.

Hamilton’s general drinking water supply is not impacted.

For more information, call Public Health Services’s safe water info line at 905-546-2189 or visit hamilton.ca/safewater.