Wellington Water is responding to an outbreak of avian botulism affecting birdlife at the oxidation pond next to the Greytown Wastewater Treatment Plant.

A number of dead and sick waterfowl have been found on the pond, and expert advice from Biosecurity New Zealand indicates the likely cause is avian botulism.

The risk to the public is low. However, people should avoid handling sick or dead birds. It can make dogs and cats, as well as other domestic pets, very sick so keep them away from dead animals if you come across them. If you see three or more sick or dead wild birds in a group, report it to the Biosecurity New Zealand exotic pests and disease hotline on 0800 80 99 66.

The Greytown Wastewater Treatment process is not affected. The issue is limited to the oxidation pond, which is separate from the drinking water and wastewater networks.

Greater Wellington Regional Council (GWRC) has also been notified. There have been similar issues occurring at the Carterton and Masterton oxidation ponds.

Avian botulism is a naturally occurring toxin produced under warm, low‑oxygen conditions in shallow water bodies. It is not the same as Highly Pathogenic Avian Influenza (Bird Flu), which Biosecurity New Zealand has advised is not suspected in this case.

Wellington Water is arranging for a local contractor experienced in wildlife and environmental management to remove dead and affected birds from the site. This work helps prevent further spread of the toxin within the bird population.

ENDS