“If we cannot carry out aerial 1080 operations, more than half the country currently under intensive pest control on public conservation land will be left to the ravages of possums, rats, stoats and other pests,” Department of Conservation Director-General Alastair Morrison said today.

Mr Morrison was delivering today the opening presentation to the Environmental Risk Managment Authority hearings on the future of the use of 1080 poison in animal pest control in New Zealand, in Dunedin..

He told the hearing that at stake is the long-term health of New Zealand’s native flora and fauna, which are part of what defines our country’s national identity and way of life.

“Today the aerial application of 1080 is precise, using GPS navigation, and dosage such that every possum in the treated area would encounter and eat a bait within one to two days. The sowing rate has decreased from 6kg a hectare of cereal baits to between 1.5kg and 3kg a hectare.”

“We are not indiscriminate in the way  we use 1080.

“1080 breaks down quickly in waterways. Rigorous monitoring of water quality over more than 12 years has shown no lasting effects in water. 1080 does not accumulate in food webs. Sampling over numerous operations have shown that the effects on all non-target native wildlife is transient and has no detrimental effect at population level.”

The Department of Conservation and the Animal Health Board (concerned for the future of the control of bovine Tb, which can be transmitted by possums) asked for ERMA to re-assess the use of 1080, Mr Morrison said.

“We did so to expose all the arguments to scrutiny. We did so, confident that the valid concerns of opponents can be answered. We are confident that the objective evidence is heavily weighted in favour of the continued wise use of 1080 as one of our most critical, safest and most effective pest control tools.”

Mr Morrison provided a number of practical case studies to illustrate the value of 1080 to indigenous species.

The use of aerially-broadcast 1080 poison in the Dart and Caples valleys (6000 ha) in the South Island this year illustrated the strategic role that 1080 poison plays in biodiversity conservation, Mr Morrison said.

At issue was an abnormally prolific beech flowering season leading to a predicted explosion in the population of rats, a key predator of the mohua/yellowhead, a once common forest bird, now facing extinction.

Of 24 nests in the area managed with 1080 poison to control possums and rats, 22 carried all of their young through to fledging, he said. “In a nearby non-treatment area, we were hoping to find at least 10. We found six. Four managed to fledge young.”

“The positive outcome for the Dart underlines the value of aerial 1080 as a critical tool for species management. Without 1080, the mohua population would have suffered a catastrophic knockdown that predictably it would never recover from.”

Mr Morrison said that scientists had been looking into the effect of 1080 operations on kiwi populations. In 1998 at Okarito, South Westland, none of 26 tagged kiwi were affected. In the mid-1990s in Northland, 35 radio-tagged adult kiwi had survived six months after the operation and 33 of them were alive one year after the 1080 operation.

In September 2006 14,000 ha of Tongariro Forest was treated with aerial 1080, in the knowledge that an earlier operation, in 2001, had led to an increase in chick survival rates. Measurements afterwards showed a decline in stoat and rat densities, and at last count three kiwi had reached the critical size at which they are able to defend themselves against stoats.

"So the stakes are high. I cannot overstate the impact that a decision to cease or restrict the use of 1080 would have. Without 1080, the price New Zealanders would have to pay in the loss of their unique species and habitats is too awful to contemplate.”