The recent warm wet weather has created perfect conditions for naturally occurring Cyanobacteria, or toxic algae, to bloom in some rivers and streams.

Toxic algae can produce toxins that are harmful to humans, dogs, livestock and wildlife when eaten.

We’ve found warning levels in some areas of the Maitai/Mahitahi River and recommend keeping dogs and humans out of rivers and streams if you suspect toxic algae may be present.

We’ll put up signs where we know that toxic algae levels are a problem, but recommend you exercise caution as the situation can change quickly.

If in doubt – keep your dogs out of the water. The Back Beach at Tahunanui provides a great alternative off-lead dog exercise and swimming area at this time of year.
What to look for

Toxic algal mats are dark brown or black and grow attached to rocks on the river bed. Mats that come loose from the river bed can wash up on the river bank or form floating ‘rafts’ in shallow areas.

Where exposed, the mats may dry out and turn a light brown colour. They also have a strong musty odour, which may attract dogs to eat them.

If you see toxic algae mats, avoid contact with it and keep your dogs and children out of the water.
What should you do:

  • If you think your dog has eaten toxic algae, contact your vet as soon as possible as the toxins can take effect within minutes.
  • If a person experiences a reaction to toxic algae, seek medical help immediately.

For more information visit our website