Compound 1080 (sodium fluoroacetate) is a synthetic form of a natural biodegradable non-accumulating plant toxin which occurs naturally in over 40 plants throughout five subcontinents, including the plant camellia sinensis from which tea is made. 1080 was discovered in Belgium in 1896 and was first used as a pest control agent in Poland in the late 1930’s.
Weight for weight less toxic than uncooked baked beans it represents a very cost effective animal pest management tool in certain situations, such as large areas and difficult terrain. 1080 has no known antidote and is currently used in Australia, Mexico, Japan, United States, Israel and also by the World Health Organisation.
In New Zealand, MAF recently estimated that approximately 70 million possums consume 22,000 tonnes of our forests every night. Feral colonies of these introduced creatures can, and do spread Bovine TB, and their exploding populations are putting at risk over $5 billion worth of beef, deer and dairy export trade. Many of our trading partners are TB free and if they where to impose stricter controls our primary produce exporters could be shut out. The effective control of the furry invaders is essential to the future wellbeing of not only the rural sector but the entire country.
In recent years MAF have surveyed and investigated to determine the best course of action under three broad methods of control: manual, poisoning and biological.
Manual methods such as shooting and trapping have proven ineffective over the long term, even when their fur carries a high price, although shooting is considered the most humane. Biological methods include: imports of possum specific parasites, bacterium or viruses, genetically engineered organisms (GMO) and methods that stop breeding such as immuno-contraception or sterilisation inducing controls.
1080 poison remains the most cost effective and biodegradable method of control for our feral populations of possums particularly in large scale and otherwise inaccessible areas, although concerns have recently been raised regarding potential residues threatening farmed stock.
MAF’s National Residues Manager in Wellington, Caroline Keast, commented that MAF operates an annual National Residue Monitoring Programme which monitors the chemical status of feral animals and farm stock. "We work alongside councils and DOC to have poisons laid to avoid the exposure of farm stock to these substances, and MAF requirements restrict the sourcing of feral animals only to areas where poisons have not been laid."
"Poisons have been monitored for the past 3 years in feral animals, and farm animals are included in the 1999/2000 programme. Stock samples were taken early in February and the results should be available any day now. No residues have been found to date," she said.
The TDC has a history of 1080 programmes and are involved in the more delicate programmes on the edges between DOC lands and rural lands. In 1994 they had a programme throughout the Murchison area and last month they did some work on the Aorere Valley in the Golden Bay. "This was in conjunction with DOC " explained Robin Van Zoelan from the TDC. "We just filled in a few gaps. Principally we undertake vector controls to protect farm stock from Bovine TB, particularly with possums invading from the edge of Kahurangi National Park."
"In some instances we have blocks with particular shapes where we apply right to the edge of farm land. We work closely with the farmers to ensure that no stock will be allowed in that area until deemed to be safe."
"1080 has been used since the 1950’s and there are very sensitive ways and means of testing for residues, and also the chemical structure breaks down in animals within a few days." Mr Van Zoelan said.
Mike Hawes, DOC Technical Support Officer in Nelson agrees " We have quite stringent procedures in place to insure stock don’t have access to baits. Certainly all the aerial operations we do use GPS systems on the helicopters to eliminate over flying the specified areas."
"For this calendar year 2000, we have all together 13 possum control operations planned, one is an aerial 1080 operation at Mt Burnett in Golden Bay in conjunction with TDC, three of those involve ground laying of 1080, and the other 9 are mixes with cyanide and cholecalciferol using bait stations and traps. All these are maintenance programmes of existing operations"
Highlighting the damage possums do, Mr Hawes confirmed, "conservation losses from loss of habitat, loss of particular plant species like mistletoes and the loss of animal species. They predate on land snails, take kiwi and kokako eggs, and even young birds as well, so they have a broad range of impact on both plants and animals."
Consider this tonight, as possums consume another 22,000 tonnes of your national assets.
