Swimming warning for Tukituki River

The Hawke's Bay District Health Board has released an official swimming warning advising people not to swim at some locations along the Tukituki River. Photo / Warren Buckland

The Hawke's Bay District Health Board has released an official swimming warning for popular spots Patangata, Horseshoe Bend and Red Bridge in the Tukituki River following today's results that showed increased levels of cyanobacteria mats (algal blooms).

Hawke's Bay Regional Council's weekly routine monitoring results, received today, show cyanobacteria mat coverage now at official health warning status 'red' for Patangata at 51.5% algal coverage, while Horseshoe Bend and Red Bridge are categorised at 'amber' level, on the cusp of an official health alert, with coverage at 48% and 35% respectively.

Hawke's Bay District Health Board Medical Officer of Health, Dr Caroline McElnay said people were not to swim at Patangata and were also advised to avoid swimming at Horseshoe Bend and Red Bridge given coverage levels remained on the rise.

Cyanobacterial mats (algae blooms) exist in rivers naturally, but can form mats in continuing warm, dry weather and low river flows. These mats can become toxic. Particular caution needs to be taken with algal mats that are floating on the surface or washed up on the river's edge.

Hawke's Bay's summer weather conditions, resulting in lower river flows and warmer water temperatures, increased the likelihood of algal blooms in the region's fresh waterways, which can be toxic to humans and dogs.

Dr McElnay said algal mats are identifiable by a strong musty odour and can vary in colour from dark green/brown to a pale brown/whitish colour when dry.

"Any contact with a toxic form of the algal mat may cause vomiting, diarrhoea and skin irritations in humans," Dr McElnay said.

"Dogs are particularly susceptible to the toxins, and owners are advised to avoid allowing their dogs to scavenge on the river's edge."

Dr McElnay said swimming should be avoided in the detected areas and warning signs had been erected.

"Anyone who displays signs of illness after being in a river bed should seek medical advice from a doctor immediately," Dr McElnay said.

"Similarly, any dogs or other animals that get sick after being in a river should get prompt veterinary attention," she said.

Hawke's Bay Regional Council would continue to carry out routine monitoring on a weekly basis and the public would be kept up-to-date of any changes in algal mat coverage.