A health warning has been issued for Waihī Estuary at Pukehina because of a bloom of potentially toxic algae.
According to Toi Te Ora Public Health, the algae is forming mats in the shallow areas of the estuary and these may float free and spread through the estuary.
Contact with toxic algae can cause asthma, hayfever attacks and skin rashes.
If swallowed it may cause stomach upsets, headaches, tingling around the mouth, and in severe cases, muscle paralysis and difficulty breathing.