Blue-green algae has been identified by the City of Hamilton in the western harbour. Blue-green algae can harbour a liver neurotoxin that can cause headaches, fever, diarrhea, nausea and rashes. Individuals should avoid contact if possible, and wash with clean water as soon as possible after coming into contact with the water.
The algae blooms are related to high levels of nutrients in the harbour, notably phosphorus and nitrogen. Although the concentrations have come down significantly over the past decades and upgrades to storm water management and the Woodward waste water treatment plant are expected to further reduce nutrient loading, a reduction in algae may not be visible for years. The City of Hamilton and the Hamilton Harbour Remedial Action Plan have tested localized algae prevention and treatment options with no success.
The city has put out a press release with more information.