People are being warned to protect themselves and their dogs against toxic algae in Masterton's Waipoua River after levels increased.
Weekly river monitoring by Greater Wellington Regional Council (GWRC) has shown increased coverage of toxic algae at its Colombo Rd monitoring site presenting a potential risk to river users.
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.
Along with Masterton District Council and Regional Public Health, the regional council is urging river users to be careful, and warning signs have been put up.
GWRC environmental monitoring officer Brett Cockeram said the algae has a pungent smell and often clumps together once it is washed off the rocks. Mr Cockeram said the spot next to the Colombo Rd Bridge was quite popular with people and dogs, and the last death of a dog he could recall happened in 2010. The algae has been an ongoing problem but "wasn't quite so bad last year" because of the rain. GWRC aquatic ecosystems and quality team leader Juliet Milne said toxic algae can be abundant in many New Zealand waterways during summer.
