Medical Officer of Health Dr Neil de Wet said the health warning meant people should avoid any activity involving contact with the water in Waihī Estuary.
"Algal mats may also accumulate along the shoreline of the estuary and around its mouth and so it's especially important that parents ensure that children avoid contact with these mats as they may be toxic.
"Shellfish accumulate the toxin and so it's advised that shellfish are not collected from anywhere in Waihī Estuary or the estuary mouth," he said.
Dogs are particularly at risk and should be kept away from the shoreline or areas where algal mats may accumulate. Elsewhere in New Zealand this type of algal bloom has resulted in deaths of dogs that have eaten algal mats or drunk affected water.
Up-to-date information on this health warning and others for the Bay of Plenty and Lakes districts is available through these channels:
- Phone: 0800 221 555
- Website: www.toiteora.govt.nz/health_warnings
- Facebook: www.facebook.com/toiteora
- Twitter: www.twitter.com/toiteora
- Email alerts for subscribers: www.toiteora.govt.nz/alert