Townsville City Council's routine water quality testing program has detected a large algal bloom in Curralea lakes near Castletown Shopping Centre.
Algal blooms are a common occurrence in tropical waterways.
Rainfall is known to wash nutrients such as residential lawn fertiliser, grass clippings and soil into the lakes.
These nutrients, combined with the hot, still and dry conditions create ideal conditions for algae to bloom.
Algal blooms can cause skin irritations and make pets sick if they drink the water.
Very large algal blooms can also lead to a deterioration in water quality, which in some cases can cause fish kills.
Council has erected signage around the lake advising the public to avoid direct contact with the water.
A biological catalyst has been applied to the lake to suppress odour and rebalance the system and additional pumping of water to create flow to reduce the risk of a fish kill will be implemented.
Pets should be kept away from the water and any fish caught should not be consumed.
Council will continue to monitor the situation.
