Dog owners warned as toxic algae 'red flags' raised for Hutt River
Monday, 27 November 2017
Toxic algae has been found in the Hutt River and is again posing danger.
Six 'red flag' alerts are on the Greater Wellington Regional Council's water quality site but no further warnings to the community are in place.
Instead the council is encouraging 'self-monitoring' of a problem which in recent years has resulted in the death of dogs and raised much public concern.
Warnings at the Kaitoke Regional Park camp ground and the Hutt Forks location detail high algae levels and the river is unsafe for swimming. Dog owners are recommended to stay away.
**READ MORE:
* Call for action on toxic algae
* Keep an eye out for toxic algae in Nelson waterways as weather settles
* Potentially toxic algae confirmed in Cardrona River**
Elevated toxic levels are also reported at Melling, Belmont, Silverstream and Birchville. While warning people to avoid algae washed up at the rivers' edge and to keep dogs on a lead, the council says 'it is still safe to use the river' in these locations.
'The presence of these red flags shows toxic algae is present but doesn't automatically trigger warning signs for the public,' council spokesperson Stephen Heath said.
'It's a temporary phenomenon and we would be installing and removing them throughout the summer so the approach we take is self-monitoring' with people encouraged to check before they swim.
Several people walking dogs near Lower Hutt's Melling Bridge, including Caroline Angus, were surprised to learn algae was in the river.
She said there were no warning notices near the river and with the hot weather and lack of flow it was a bad sign for the summer.
While her dog did not like water Angus said she would be extra careful near the river.
Sharon Greenfield, who regularly takes Bella for a river walk, was aware of the algae alert and planned to make sure her dog did not go near the water.
'She mostly stays with me and I do not let her anywhere near the river. If I am concerned she is going to wander, I put her on a a lead.'
Heath said the regional council approach was to provide information which directed the public to its website for more details.
'We are rolling more of these out in the upper Hutt Valley.'
Where there was 'prolonged and well-established' algae, communication of the safety risk would be intensified, he said.
That would include media releases, information to vets and dog owners and social media posting.
Triggered by hot weather and low rain, the algae has arrived earlier than in recent years.
The red flag alerts were based on November 20 testing.
From December the council will move to weekly testing of Wellington's waterways and updates will be more frequent.
People coming into contact with the algae can experience vomiting, diarrhoea and skin irritations.
It is also very dangerous for dogs which can die a short time after eating the algae which forms into mats attached to river stones.
* For the latest information see: gw.govt.nz/is-it-safe-to-swim/
WHAT IS TOXIC ALGAE?
* Freshwater toxic algae, known scientifically as cyanobacteria, are an ancient group of photosynthetic bacteria. Cyanobacteria are widespread in rivers and lakes including waterways with good water quality.
* In certain conditions it forms extensive blooms which can be toxic to humans, dogs, livestock and wildlife.
* Exposure to high levels of toxins can result in serious illness or death. Dogs are particularly susceptible as they love to scavenge and play near water.
* In rivers, cyanobacteria form brown or black mats that grow on rocks in the river bed.
* Mats that come loose from the river wash up on the river bank or form floating 'rafts' in shallow water.
* When exposed, the mats may dry out and turn a light brown or white colour and produce a strong musty odour.
* Cyanobacteria differs from the green algae that is common in rivers and is harmless.