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Toi Te Ora: Health warning issued for Lake Okaro

Wednesday, 14 December 2011 3:30 p.m.

A health warning has been issued for Lake Okaro today as routine summer monitoring results provided by Bay of Plenty Regional Council have confirmed blooms of blue-green algae which are potentially toxic.

"Blue-green algae are present in Lake Okaro at levels that may result in adverse health effects and so it is advisable for people to avoid contact with the water," says Dr Phil Shoemack, Medical Officer of Health. 

Contact with algal blooms can trigger asthma and hayfever attacks in susceptible individuals, as well as causing skin rashes, stomach upsets, and in some cases neurological effects such as tingling around the mouth, headaches, breathing difficulties and visual problems. 

Lake Okaro, near Rainbow Mountain, approximately twenty kilometres to the south of Rotorua, is prone to blooms, some of which persist for several months.  Signage will be erected at Lake Okaro advising potential lake users of the algal bloom. 

"Ongoing weekly monitoring of the main lakes and rivers in the Bay of Plenty will continue throughout the summer and the public will be advised where high levels of blue-green algae are detected" says Dr Shoemack.  "However, in the right conditions algal blooms can develop rapidly and unpredictably, so wherever you are swimming this summer it is important to 'look before you leap' and make your own judgement of the water - if in doubt stay out."

If the water has a musty smell, if it appears murky with a blue or greenish tinge, or if there is a scum on the surface, people should avoid entering the water. Pets should also be kept away from areas where blooms are present.

For more information, please contact Toi Te Ora Public Health Service on 07 577 3770 or visit

Lake Okaro walkway lowres