A Dunedin City Council spokesman said yesterday 1331 birds were known to have died as a result of the disease that started at Waikouaiti wastewater treatment plant oxidation ponds this month.
Most of the birds that have died from the disease were paradise shelducks, rendered flightless at the time due to their annual moult.
The spokesman said the recovery and burial of bird carcasses in and around the treatment plant's oxidation ponds to help break the chain of infection continued.
City council discussions with other councils in the region involved briefing them on the steps taken by the council and other organisations to manage the situation, he said.
"In addition to our immediate response, we'll also be working with Otago Fish & Game to consider any steps we can take in future to try to avoid any repeat.
"This may include deterrents designed to discourage birds from using the oxidation ponds as a moulting site."
Low oxygen levels in the ponds and warm water temperatures have been identified as conditions likely to have sparked the outbreak.
Fish & Game has said the disease was more common in the North Island where wastewater treatment plants were considered "hotspots" for outbreaks.
Otago Regional Council compliance manager Carlo Bell said yesterday regional council staff had been on site at Waikouaiti and had checked whether the plant was compliant with its consent conditions, and had "no concerns".
Mr Bell confirmed this was the first outbreak of avian botulism in the region known to the council.
Massey University distinguished professor Nigel French said die-offs of this size could have a significant impact on bird populations and there was some concern it could involve taonga species.
Prof French said the ability for the bacteria behind the disease to grow in low oxygen environments, including the bodies of dead birds, meant "the rapid removal of dead birds" from the site of an outbreak was a key factor in limiting its impact.
He also said it was a good idea to try to revisit the procedures around the management of treatment plants to try to avoid outbreaks in the future.
