The Canterbury District Health Board is warning people to stay out of the Ashburton River because potentially toxic blue-green algae have been found in it.
The Canterbury District Health Board is warning people to stay out of the Ashburton River because potentially toxic blue-green algae have been found in it.
Residents of nearby Ashburton were being warned not to swim in the river or let their dogs use it.
Exposure to the algae can cause skin rashes, nausea, stomach cramps, and numbness around the mouth and fingertips.
Anybody experiencing those symptoms was advised to see their doctor immediately.
Boiling water did not remove the problem.
The river was being monitored.
Algae found in Waipoua River
Toxic algae has also been found in parts of the Waipoua River, near Masterton, prompting authorities to warn dog owners to keep their dogs on the lead and for people to take care.
Wellington Regional Council which monitored the river said clumps of the brown or black algal mats were washing up along the river's edge at Colombo Road.
It said the algae, if ingested could kill livestock and dogs, and contact can cause vomiting, diarrhoea and skin irritations in humans.
Warning notices had been posted at access points along the river.
