Dead duck mystery: 1080 not cause of death, DOC says

Dead ducks found beside a river near Glenorchy were not poisoned by 1080, but test results offer no other clues to the cause of their death.

The Department of Conservation ordered autopsies on several of the paradise ducks, discovered dead in January, while the Otago Regional Council sent river water from where they were discovered for testing.

Results from all of the tests are now in, and neither authority is able to offer any explanation for the deaths based on what they reveal.

Department of Conservation Whakatipu operations manager David Butt says samples from the birds were sent for testing by Manaaki Whenua/Landcare Research.

Here, staff were specifically on the look out for traces of 1080, but they didn't find any.

"These tests did not find any detectable fluoroacetate, thus ruling out 1080 as a possible cause of death," Mr Butt says.

Buckler Burn (left) and Rees River (right) six days apart: There was no obvious cause of death, and now test results offer no further clues - what's behind Glenorchy's dead ducks? (Images: Facebook).

Fluoroacetate, or sodium fluoroacetate, is the compound more commonly known as 1080. The last 1080 drop at the head of Lake Whakatipu was on December 3 in the Dart, Routeburn and Caples area.

Another of the ducks was sent to Massey University for a "general autopsy", and this, also, did not identify a cause of death.

The Department of Conservation will not be doing any further testing, he says.

Meanwhile, tests of water samples taken from the Buckler Burn, a waterway some of the ducks were found lying in, have revealed no signs of pollution.

"The water quality test was clear, so cause of death has not been established," ORC compliance manager Tami Sargeant says.

The tests were spurred after members of the public came upon the animal carcasses on January 19 in the Buckler Burn, which empties into Lake Whakatipu at Glenorchy.

Six days later, more were found by locals walking along a stretch of the Rees River, where it meets the creek that runs from Glenorchy Lagoon - a separate waterway from where the first ducks were found.

The Otago Regional Council has lead the investigation into the cause of death.