Potentially toxic algal bloom spreads

A potentially toxic algal bloom has spread to Lake Rotorua, prompting a health warning to be issued on the lake for the first time in years.

High levels of cyanobacteria in Lake Rotorua late last week sparked a health warning for Holden's Bay, Hannah's Bay and the Ohau Channel.

Bay of Plenty medical officer of health Phil Shoemack issued the warning in addition to those already in place for the whole of Lakes Rotoiti and Rotoehu.

Dr Shoemack said water from the affected areas of Lake Rotorua should not be used for drinking or any activity that would induce skin contact.

Cyanobacteria can release toxins that may affect the liver and nervous system, cause skin rashes and set off hayfever or asthma attacks in some people.