New possum poison approved

A new ground-based possum poison has been approved for import and manufacture by the Environmental Protection Authority (EPA).

The EPA approved the application last week citing a number of advantages such as reduced secondary and tertiary poisoning of livestock and domestic animals associated with brodifacoum, 1080, diphacinone and pindone.

The poison, zinc phosphide, will target brush-tailed possums and does not leave residues in venison for export or domestic consumption.

The EPA has imposed strict conditions on its use, including limiting it to trained and licensed operators.

The application was made by Pest Tech Ltd, with support from Connovation Ltd, Lincoln University and the Animal Health Board (AHB).

Its approval was supported by the Federated Farmers, the Department of Conservation (DOC) and some regional councils, while it was opposed by three individuals. No conservation or hunting and fishing groups submitted against it.

Around 80 percent of the AHB possum control - to stop the spread of bovine tuberculosis - was with ground traps and toxins, the rest with aerially applied 1080.

AHB manager of Tb research Paul Livingstone told NZPA zinc phosphide would not be applied aerially and would not be a replacement for the controversial 1080. It would sit alongside the likes of brodifacoum, Feratox and cholecalciferol.

Its advantages were that it was effective on possums and there was no secondary poisoning effects, so it would not kill dogs, he said.

However, because there was no secondary poisoning it would kill rats, but not the stoats that ate those rats.

Mr Livingstone said how much of the new poison would be used would be determined by pest control operators, and if it suited their needs.

Connovation chief executive Duncan MacMorran said it was a slow process getting approval, with the AHB starting the process four or five years ago.

He believed there would be a lot of interest because it did not have some of the issues of 1080 and did not have the biosecurity issues of brodifacoum's half life and secondary kills.

Zinc phosphide was ''just another tool in the tool box''.

Mr MacMorran said the poison would be ''moderately priced'' although the final price had not yet been set.

The encapsulation and bait making would be done in Auckland, with the zinc phosphide chemical coming from either China or India.

It would hit the market in three or four months, he said.

DOC pest control advocate Harry Broad also described zinc phosphide as another tool in the tool-kit.

DOC would first look at its cost-effectiveness and whether it was a humane poison and would need to trial the poison.

''We still aren't clear what the cost per hectare will be, and will it give us a good a hit as other methods we are using.''

The Dominion Post