Townsville City Council's regular water quality testing program has detected blue-green algal blooms in Curralea and Keyatta lakes near Castletown Shopping Centre.
Algal blooms are a common occurrence in tropical environments at this time of year.
Rainfall washes nutrients like lawn fertiliser, grass clippings and soil into the lakes. These nutrients, combined with the current hot, still and dry conditions, can encourage algae to bloom.
"Council is monitoring in and around the lakes and has undertaken multiple biological treatments in recent days to help support and balance ecological conditions in both lakes over the Christmas period," a spokesperson for Townsville City Council said.
"Blue green algae can cause skin irritations and make pets sick if they drink the water. At this time, we ask the public to avoid contact with the water in the lakes. Pets should also be kept away from the water and any fish caught should not be consumed."
Council will continue to monitor the situation.
