A health warning has been issued for Ōtautū Bay in Lake Rotoehu due to a bloom of potentially toxic blue-green algae.
The medical officer of health said in a statement people should avoid any activity that resulted in contact with the water.
“These algal blooms have the capacity to release toxins into the water which can cause significant ill-health to anyone who has contact with the water.
“The toxins can affect the nervous system causing numbness and difficulty with breathing, and also sparking asthma attacks,” the statement said.