Monitoring of the Waipoua River at Colombo Rd in Masterton by the regional council shows that toxic algae levels are now high.
Clumps of the algal mats, which are brown or black, are also washing up on the river's edge. Toxic algae can kill livestock and dogs -- if your dog eats toxic algae, it can die very quickly. In humans, contact with toxic algae can cause vomiting, diarrhoea, skin irritations and other allergy-type symptoms.
"It's more than a month since there's been decent rainfall in the Waipoua River catchment, and this, combined with warm weather, has resulted in rapid toxic algae growth. The amount of toxic algae in the river is likely to remain high until there's a significant amount of rainfall," Greater Wellington senior environmental scientist Summer Greenfield said.
Masterton District Council has posted information signs at key access points along the river. Monitoring of Wellington waterways and coastal areas is carried out by Greater Wellington Regional Council and local authorities on a weekly basis over the summer months. Results of the monitoring and latest warnings are posted on www.gw.govt.nz/summer-check.
Other information about toxic algae, including a guide of what to look for and what to do if you are worried about possible contact with toxic algae, can be found at www.gw.govt.nz/toxic-algae-faqs .
