People and their pets are being urged to stay away from potentially toxic blue-green algae mats in the Tukituki River.
While people were generally advised to avoid contact with the algae mats, it had reached "warning level" at both Walker Rd and Tamumu Bridge, Hawke's Bay District Health Board Medical Officer of Health Nicholas Jones said.
Monitoring by Hawke's Bay Regional Council had identified growth of potentially toxic blue-green algae mats in several stretches of the Tukituki River.
Signs had been put up warning people to be cautious around algal mats that were floating on the surface or washed up on the river edge.
Algae existed in rivers naturally, but could form mats in continuing warm, dry weather and low river flows, Mr Jones said.
These mats could become toxic. When blue-green algal mats became exposed and easily accessible to people, dogs, and stock they became a health risk.
The algal mats had a strong musty odour and could vary in colour from dark green/brown to a pale brown/whitish colour when dry.
Mr Jones said that contact with the toxic form of the algae could cause vomiting, diarrhoea and skin irritations in humans. Dogs were particularly susceptible to the toxins, and owners were advised to avoid allowing their dogs to scavenge on the river's edge.
If any person displays signs of illness after being in a river bed, seek medical advice from a doctor immediately. Similarly, any dogs or other animals that get sick after being in a river should get prompt veterinary attention.
To get the latest information phone the B4USWIM line (0800 B4U SWIM/0800 248 7946) or go to Hawke's Bay Regional Council's website, www.hbrc.govt.nz.
The regional council will continue to monitor the situation.