Application for improved rabbit biocontrol

Environment Canterbury announced today that its application on behalf of a co-ordinating group (“RCG”) to release a new variant of rabbit haemorrhagic disease was aiming for a release date of March 2018.

The new variant, known as RHDV1 K5, has already been approved in Australia and release there is currently underway.

Graham Sullivan, Environment Canterbury Regional Leader Biosecurity, said the targeted release date was later than originally anticipated because further work was needed to address the regulations permitting legal importation of the new variant.

“The revised timeframe will allow the RCG to learn valuable lessons from the Australian release,” Mr Sullivan said.

RHDV1 K5 is expected to boost the effects of the existing RHDV1 strain and help slow the increase in wild rabbit numbers. “While exact figures are unknown, we expect improved knockdown in areas where the current strain is less effective,” Mr Sullivan said. “Research shows that autumn is the best time to release the virus because immune young rabbit numbers are low and vectors such as flies are active.”

Patience and support would be required from landowners, farmers and other stakeholders who were likely to benefit from the release. The greatest likelihood of success will come from the collaborative efforts of the RCG, regional councils and landowners. “A controlled release will also ensure that a high-quality commercially prepared product can be made available in order to improve effectiveness,” Graham Sullivan said.

An illegal or unmanaged release would significantly compromise the benefits. A substantial risk of any unmanaged release is the likelihood of bringing the rogue RHDV2 virus into New Zealand. RHDV2 is present in Australia and its potential impacts on non-target species is unknown, so it presents a significant biosecurity risk.

To maximise the effectiveness of the new variant, regional councils and researchers are proposing a nationally consistent release process with appropriate monitoring. “These actions will help safeguard the potential introduction of further biological control agents in future,” Mr Sullivan said.

Pet rabbit owners are understandably concerned about the possible impact of a new RHD variant. “A vaccine is available to protect pet rabbits from the current RHDV strain,” Mr Sullivan said. “A key part of the application assessment by the Ministry for Primary Industries will be whether an effective vaccine is available to protect farmed and pet rabbits from the new variant. The virus only infects rabbits and there are no human health risks associated with RHDV1.”

Background

The New Zealand Rabbit Coordination Group (RCG) is co-ordinating the approvals processes for RHDV1 K5. The RCG includes representatives from regional and district councils, Federated Farmers, the Department of Conservation, the Ministry for Primary Industries and Land Information New Zealand. Environment Canterbury is the applicant for the approvals on behalf of the RCG.

Two statutory approvals are required to register, import and release RHDV1 K5 in New Zealand:

• Registration under the Agricultural Compounds and Veterinary Medicines Act (ACVM)
• An unwanted organism permission under sections 52 and 53 the Biosecurity Act (BSA).

A Hazardous Substances and New Organisms Act (HSNO) approval from the Environmental Protection Authority (EPA) is not required.

The approvals process is being run in parallel with a Landcare Research Sustainable Farming Fund project to prepare a release strategy for RHDV1-K5. This will help participating regional and district councils to effectively release RHDV1 K5 in rabbit-prone areas. The strategy will also include pre and post release monitoring to measure impacts and inform future research.