In a joint statement released yesterday, Otago and Southland Fish & Game said they were dismayed the government agency had elected not to conduct further testing of birds discovered in Wānaka and Te Anau last month after their biosecurity unit ruled out exotic disease as the cause of death.
More than 60 paradise shelducks were found dead in Te Anau on April 4, followed by close to 100 dead birds in Dublin Bay, Wānaka, between April 22-23.
The councils said they suspected the insecticide Diazinon was to blame in both of the incidents and would be testing samples themselves for confirmation.
They said there was "no suggestion the recent mass bird kills were intentional".
Southland Fish & Game manager Zane Moss said a separate incident, where a landowner contacted Southland Fish & Game over concerns they had accidentally poisoned shelduck through application of Diazinon — banned in the European Union but not here — was enough to suggest the MPI should be doing more to investigate mass bird deaths.
"It’s clear from one of the farmers who contacted Fish & Game that this product is extremely toxic to birds, so to have the agency responsible deliberately ignore the risks is abhorrent."
Otago Fish & Game chief executive Ian Hadland said it was important to know the cause of any mass death of wildlife, especially native bird species.
"I would have thought MPI would be as interested as us in confirming the cause of death, but unfortunately they have walked away.
"It’s like they don’t want to know.
"It’s unacceptable that a not-for-profit organisation like Fish & Game has to use licence-holder funds to mop up an incomplete investigation by a large government department such as MPI."
Biosecurity New Zealand deputy director-general Stuart Anderson said it was inaccurate to suggest the MPI was "disinterested" or had "walked away". The agency had fulfilled its role of ruling out exotic disease such as highly pathogenic avian influenza as the cause of the deaths.
"We discussed with Fish & Game that our role was exotic-disease testing, which is what we are funded to provide, and our laboratory would not do toxicology testing, which is outside our remit."
Biosecurity New Zealand investigated all reports of multiple bird fatalities, and acknowledged while there had been an "uptick in notifications" in recent years, this was likely due to heightened awareness rather than an increased amount of disease.
Otago Regional Council compliance manager Tami Sargeant said council staff had not been involved in the MPI investigation, but had conducted its own independent testing of water from the Dublin Bay site, with no results of concern.
Diazinon is a registered insecticide used by the New Zealand agricultural industry.
Fish & Game did not give a timeframe on when the toxicology testing would be completed.
