Warning as toxic algae builds up in the Ruamahanga River
The Greater Wellington Regional Council, Carterton District Council and Regional Public Health are urging river users to protect themselves and their dogs from toxic algae, with an increase of algal growth detected in the middle reaches of the Ruamahanga River this week.
Toxic algae – or cyanobacteria – form brown or black clumps on river beds and can kill livestock and dogs. The clumps can peel off and often wash up on the river’s edge where dogs can easily come into contact with them. If your dog eats toxic algae, it can die very quickly. Contact with toxic algae can cause vomiting, diarrhoea, skin irritations and other allergy-type symptoms in humans.
The Regional Council’s weekly river monitoring has shown increased coverage of toxic algae at its Kokotau monitoring site, just upstream of the Kokotau Bridge, on the Ruamahanga, presenting a potential risk to river users. Carterton District Council staff are putting up warning signs along key access points to the river.
Regional Council Senior Environmental Scientist, Summer Greenfield, says that toxic algae can be abundant in many New Zealand waterways during summer.
“The warm weather in the Wairarapa is a key factor behind the increase. The risk to river users and dogs is likely to remain until there’s significant rainfall to flush the algae away.”
The Waipoua River in Masterton continues to present a high risk to users from toxic algae.