Foreword
The introduction of mammal pests such as rabbits, stoats, ferrets and possums to New Zealand has resulted in a unique and complex set of ecological and animal disease control problems that we struggle to manage.
For more than 50 years the main response to these problems has been the use of a mixture of population control methods. These have mainly targeted the brush-tailed possum, first introduced from Australia in 1858, which has flourished in its new environment, rich in food and free of natural predators. More recent pest control efforts on the mainland have targeted stoats and ferrets, originally introduced in a misguided attempt to control yet another pest, the rabbit. Integrated, multiple-pest control programmes are being developed as we learn more about the extreme risks which many native species face from the mixed impacts of introduced mammals.
In recent years these pest control programmes have delivered real successes. The North Island kokako has been brought back from a rapid slide towards extinction. The collapse of forest canopies due to possum browse has been arrested or reversed in some of our finest native forests. The incidence of bovine Tb in cattle and deer herds has fallen dramatically.
Our ability to maintain effective control of mammal pests over large areas remains limited by the control tools at our disposal. Despite extensive and promising research into biological control, traditional trap and poison technology will remain the mainstay of animal pest control in New Zealand for the foreseeable future.
The toxin sodium monofluoroacetate (1080) is used mainly for possum control and is the only toxin able to be applied aerially. The ability to apply 1080 from the air makes it a key tool for possum control. It also makes it a controversial one. Concerns have long been raised about potential adverse impacts on native birds and insects, contamination of the environment and water supplies, and possible human health risks. The use of 1080 can and does kill deer that are valued for recreational hunting, and there have been incidents of accidental poisoning of livestock and domestic animals.
There is no doubt that as well as conferring major possum control benefits, the aerial application of 1080 carries risks that must be carefully managed, and which must be weighed against the benefits.
It is for this reason that the Animal Health Board and the Department of Conservation - the major users of 1080 in New Zealand - are preparing an application for a formal reassessment of 1080. This will be carried out by the Environmental Risk Management Authority (ERMA) under the Hazardous Substances and New Organisms Act (HSNO) 1996.
It is timely to reassess 1080. Recent increases in funding for both Tb control and conservation programmes are seeing an increase in possum control, which has in turn prompted an increase in concern over possible adverse effects. Monitoring and research work over the last decade has given us a more precise understanding of the benefits and risks of using 1080. The HSNO Act provides for a balanced consideration of these issues by an independent statutory body in the form of ERMA.
As part of preparing the reassessment application, the Animal Health Board and the Department of Conservation are seeking the views of iwi, the public, and interested organisations on the benefits and risks of the use of 1080 for pest control in New Zealand. This discussion paper has been prepared to provide background information on the use of 1080, the associated benefits and risks, and the reassessment process itself in order to help those who wish to make submissions.
John Dalziell
Chairman, Animal Health Board
Hugh Logan
Director-General, Department of Conservation
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