Rabbit Control on Crown-Administered Riverbeds in Canterbury
Questions and Answers
What's happening?
Land Information New Zealand intends to use poisons to reduce the number of rabbits on approximately 4000 hectares of Crown-administered riverbeds in the Canterbury region. The work will take place on open riverbed sites where Environment Canterbury monitoring indicates rabbit control is necessary. Much of this work will complement rabbit control efforts being carried out by adjoining landowners under Environment Canterbury Notices of Direction. Resource consents for the LINZ control programme have been issued.
Where?
Rabbit control will take place at riverbed sites located on the Clarence, Hapuku, Waiau, Hurunui, Rakaia, Maerewhenua (Waitaki Valley) and Hakataramea (Waitaki Valley) rivers. See Table 1 below for more details.
When?
This work is scheduled to take place from mid-June and will continue into July as weather conditions permit. Adjoining landowners have been contacted about the work. Public notices will be placed in newspapers, and prominent warning signs will be erected before poisoning operations begin. These signs describe the type of poison being used, the delivery method, the precautions that must be taken, and the period in which caution should be exercised.
How is it happening?
Poison carrot baits containing either Pindone or 1080 (Sodium fluoroacetate) will be applied in the areas listed in the table below. Most of this work will be done using ground control methods in which baits are either dispensed from a device towed behind a vehicle, or dispersed by hand.
1080 poison will be applied by helicopter on two areas of riverbed in the Waiau River valley west and south of Waiau. These areas are large or difficult to access, making ground control impractical. Within these two Waiau sites the poison will be laid by hand where there is a risk of baits entering water, or in some circumstances if requested by an adjoining landowner.
Aerial prefeeds
Although most of the work involves hand laying of toxic baits, fixed wing aircraft and/or helicopters will be used at some sites to deliver ‘prefeeds’ of non toxic baits (see table below). A prefeed aims to ensure target animals are attracted to the toxic bait.
| River | Treatment method |
|---|---|
| Clarence (South Marlborough, lower reaches from Glen Alton Bridge to sea) |
|
| Hapuku (South Marlborough, between SH1 bridge and coast) |
|
| Waiau (Nth Canterbury, two sites areas south and west of Waiau) |
|
| Hurunui (Nth Canterbury, two sites next to Balmoral Forest, and a site east of SH 1) |
|
| Rakaia (mid Canterbury, above Rakaia Gorge) |
|
| Maerewhenua (Waitaki Valley, South Canterbury). Two sites: adjacent Duntroon and in Upper Maerewhenua) |
|
| Hakataramea (South Canterbury) |
|
What is the risk of baits entering water?
As the bulk of the control involves hand-laying of poison, there is an extremely low risk of baits entering water. For aerial operations, the resource consents specify that poison will not be applied within 20 metres of waterways by aerial application, or within 500 metres of a public water supply intake. Helicopter sowing of baits, using satellite navigation technology, ensures even coverage of pellets and allows the pilot to avoid specific areas, such as water intakes or flowing water. Each application of poison is followed by independent water quality monitoring 12 hours and 48 hours later.
What do the poison baits look like?
Carrots baits are cut into cubes, usually by machine, weigh about 6 grams, and are dyed green to make them less attractive to birds.
What do I need to know?
- 1080 and Pindone are poisonous to humans and domestic animals. Poisoning can occur through handling or eating bait, or eating dead or poisoned animals. All green baits should be treated as poisonous. Animal carcasses remain poisonous until they have completely decomposed.
- There is no health risk in using areas treated with 1080 or Pindone as long as bait is not handled and children are supervised, and animals are not taken from treated areas for eating. 1080 and Pindone present negligible risks to water supplies or the environment, including aquatic life and birds.
- 1080 breaks down rapidly in water to trace or immeasurable levels, usually within hours. Rain leaches the pesticide from pellets into the soil where it is broken down by micro-organisms to harmless byproducts.
- Dogs are extremely susceptible to 1080. Dogs or livestock should not be taken into treated areas for six months after poison has been laid.
- In the case of suspected Pindone poisoning, Vitamin K1 is an effective antidote.
- Recreational users of rivers or riverbed areas are advised to take note of the control operations. For their own safety, and the safety of contractors, they are advised not to enter control areas if helicopters are operating. Given the high solubility of 1080 in water, and the fact fish have a very low susceptibility to the poison, there is virtually no risk to humans taking fish to eat after a 1080 operation or in the unlikely event pellets enter the water.
What do I do if I suspect poisoning?
Contact:
- Local hospital, or
- National Poisons Centre: phone 0800 POISON – 0800 764766
- In the case of a domestic animal being poisoned contact a local veterinarian.
How well is this operation planned?
Resource consents setting out conditions the work must adhere to have been issued by Environment Canterbury. Consents from the Medical Officer of Health are gained for each operation. All pesticide operations must meet LINZ quality management standards. We have consulted/informed people most affected by the control programme.
Who do I contact for more information?
Members of the public wanting more information about specific control operations should contact: Graeme Franklyn, Landward Management Ltd, PO Box 5627, Dunedin, tel. 03 467 7094.
