About 40 black-backed gulls have died. Photo: floraandfauna.co.nz
The Department of Conservation (DOC) has confirmed about 40 black-backed gulls have died from what is believed to be avian botulism at the Waitarakao Washdyke Lagoon, near Timaru.
The news comes after it was confirmed that more than 1000 waterfowl died near the Waikouaiti wastewater treatment plant in Otago, after being infected with the disease.
Senior biodiversity ranger Ian Fraser said botulism looks to be the cause at Washdyke and tests will rule out any exotic disease.
Avian botulism is a naturally occurring bird disease triggered by environmental conditions which prompt a bacteria, found naturally in soil, to produce a toxin that causes birds to die.
Outbreaks are localised and clear naturally when conditions change.
DOC said it is monitoring the situation and plans to collect and dispose of some of the carcasses to reduce the spread to other birds in the area.
Meanwhile, Dunedin City Council (DCC) said it was confident the outbreak of avian botulism at the Waikouaiti wastewater treatment plant was contained.
It said dead birds were being recovered and buried to help stop the spread and break the chain of infection at the plant's oxidation ponds.
"At this stage, although a small number of dead birds have been found in the area immediately around the oxidation ponds, within a few hundred metres, and the outbreak remains contained to that site," A DCC spokesperson said.
The council said avian botulism was not related to avian influenza and the strain identified at the plant posed minimal risk to people.
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