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4. The intended programme in which RCD virus is proposed to be used

The Application describes how each RPMS for rabbit control is administered by a management agency. If RCD virus is introduced to New Zealand then the actioning of any formal release logically falls to each regional council, at its discretion for its region. No council can be compelled to release the virus, but release by one council may result in the spread of the virus to other regions. There are 13 regional councils/unitary authorities that have RPMS’s with controls for rabbits and the Otago Regional Council will initially coordinate the release programme.

The Application proposes that an adaptive management programme would be used for the release of the virus. Following release, effects would be monitored and the programme refined in order to optimize the impact on rabbits and the mitigation of any effects on threatened native species. There would be an initial release at 12 sites across moderate to extreme rabbit-prone land in the eastern South Island with a history of rabbit populations at or above 3 on the modified McLean scale of measurement. This would be followed by a main release at sites throughout New Zealand. There would be an option to release the virus strategically in other areas that would gain benefit. The virus would be inoculated intramuscularly into rabbits at some sites and offered as oral baits at other sites.

4.1 Statutory basis.

The legal basis to determine how, where, and by whom rabbits are managed is set out in the Biosecurity Act, 1993. Rabbits may be controlled by any landowner and must be controlled by all landowners (acting individually or collectively) under the transitional arrangements in Part X of the Biosecurity Act or under conditions to be laid out in a National or Regional Pest Management Strategies. If all regions of New Zealand declared the rabbit to be a pest then a national strategy may be appropriate. However, this is not the case and only in regions which have declared the rabbit a pest under a RPMS must land owners comply with the RPMS.

The use of RCD virus in New Zealand will not be exclusive to regional councils unless all have an RPMS or there is a national pest management strategy. The Application group have proposed that regulations made under the Animals Act, 1967 would give regional councils the authority for the sole use of the virus. However, the relevant sections in the Act have been repealed and as such it is not possible to make regulations under this Act. This matter of the legal basis of control needs to be further addressed by regional councils.

It has been suggested that while a programme for the release of RCD virus does not come under the RMA, the principles of that Act should apply. Some have said that in order for this to happen a long-term national land management strategy should be developed under the RMA. The Environment 2010 Strategy represents a commitment to the protection of New Zealand’s environment, focusing on the management of our land resources, weeds and pests. This strategy commits New Zealand to using integrated techniques that incorporate biological control to reduce the impact of pests on the environment.

4.2 Programme management agencies.

A number of supporters of RCD call for a release strategy that is planned, controlled and monitored. They place emphasis on an approach that is professional and systematic. There is some broad support expressed for the release strategy as outlined in the Application, structured to obtain maximum benefits while monitoring effects.

There is also support for consultation and involvement of farmers during the release to use the vast pool of practical knowledge which is available. Farmers in Landcare groups who presently work together towards effective rabbit control have expressed interest in co-ordinating release of the virus on their properties. It has been stressed that these people with local knowledge and vested interest should be involved. Regional councils have indicated that they would take on the role of coordinating activities of their region via the RPMS.

I believe that, ideally, there should be a lead agency, with appropriate authority, that would have a national co-ordination role for the activities of the regional councils with a RPMS, DoC, research agencies, a central laboratory and any other associated agency to ensure that RCD virus is used to maximum effect. This lead agency should have the technical expertise and resources to undertake, in cooperation with the regional councils, the surveillance for the programme. It could also take a lead role in establishing policy for the distribution of virus and monitoring the programme. Ideally, the lead agency would be part of a national pest management strategy but support for this is lacking as rabbits are not recognised as a national problem.

4.3 Details of how RCD virus will be deployed.

Several peer reviewers and public submitters have provided suggestions as to how the strategy for release could be improved. They suggest that the ecological and management basis for several choices could be better explained than in the Application and critically evaluated by a multi-disciplinary team involving wildlife scientists and managers, representatives of all stakeholders (Farmers, MAF, Regional Councils, DoC, Conservation non government organisations, animal welfare groups). They submit that the planning needs to be more detailed than provided to date.

Specific issues raised for consideration include:

  • Standardisation of monitoring methods and co-ordination of research and management have not been considered or are given scant treatment, including:


  • methods of assessing changes in rabbit abundance;


  • required sample sizes and statistical power;


  • replication of requirements for scientific interpretation;


  • stratification of sites along ecological gradients;


  • measures of of virulence and attenuation;


  • impacts on non-target species, vegetation and ecosystem processes;


  • methods for monitoring the spread of RCD infection in the rabbit population.
  • A decision to release in the North Island could be delayed as long as possible to minimise risks and use the preliminary monitoring of RCD in the South Island to guide prediction of what would happen in the North Island.
  • The basis for the choice of up to 12 release sites in the pilot phase should be explained;
  • The basis for, and the exact criteria to be met for a decision to stop or proceed to general release after the pilot phase have not been declared.
  • A two week pilot phase is a impractically short period to allow full evaluation of the pilot phase. A year may be more appropriate so that the behaviour of RCD in a wide range of seasons within New Zealand conditions can be gauged. Also, the behaviour of RCD in the first few weeks will give no indication of its true impact on the population.
  • Much could be learned if the transition to main release could be delayed sufficiently to observe spread of relatively few main foci of initial release.
  • Forest and Bird suggest that initial release sites should be chosen for their impact on ecological criteria, for the initial aim of monitoring of the impacts and efficacy of mitigating measures rather than a primary goal of rabbit control. They recommend that DoC should be a joint decision maker.
  • Inclusion of a well replicated series of pilot release sites in low density rabbit populations would be extremely valuable to assess the scale and risks of conservation impacts throughout much of New Zealand, thereby facilitating planning and research on how to protect conservation values. The release strategy seems to be based upon the economic benefit objectives and to ignore the conservation goals and risks.
  • Education and extension for landowners on land protection and improvement, and public information and awareness programmes to back up a release programme.
  • Methods of compliance with any release programme need to be addressed.

Timing of the release

RCD-induced rabbit declines would be less likely to be harmful to native birds if they occurred in late summer-early autumn (February, March, April). Predators would (hopefully) stop breeding or starve (or be trapped or poisoned) over mid-winter before the arrival and nesting of birds in August-January.

Other considerations for release dates are the welfare of kits and the number of young rabbits (which are relatively resistant to RCD) around at any one time. RCD can be expected to be more effective, with less chance of rabbit resurgence, if it hits at a time when most rabbits are older than 10 weeks. These times vary, but March-June is understood to be the general period when young rabbits are least numerous.

A further possible factor contributing toward a desired release date is daytime temperature and its effect on insect activity. In Australia it appears that the disease spread is least during the winter when insect activity is minimal and during the high temperatures of summer. However, it is not clear what insects, if any, will play a role in the transmission of RCD virus in New Zealand. Refer to section 7.4.

The initial sites for release raise a contentious point. One supporter argues that only the extreme and high rabbit-prone areas of the South Island should be targeted initially. While some concern has been raised that research needs should not interrupt the release plan, another submitter (477) argues:

"We believe that it must be made a condition of the release that there be a soundly designed and conducted epidemiological study of the field infection, using valid epidemiological and ecological research methods. Without such a study being incorporated into the release plan and adequately funded, the release should not proceed."

In order to ensure that the benefits of RCD virus are captured, in the event of a release, there should be a soundly designed and conducted epidemiological study of the field infection, using valid epidemiological and ecological research methods.

4.4 The technical and financial underpinning of the programme.

The technical and financial support for the release of RCD is not stated in the Application. However, this is the responsibility of the regional councils, and the operational plans of the RPMS’s may have to be amended to address these issues.

Following the initial importation of virus, provision must be made for the production of virus for field releases. Ideally, this would be produced in New Zealand in order to minimise the possibility of contamination with exotic organisms such as myxomatosis. However, the Applicant Group have expressed interest in sourcing the RCD virus from the Australian laboratory providing virus for release in that country. A disease risk assessment could address this source of supply.

Views on the source of funding differ among submitters. Some see the rabbit as a national problem requiring government funding. Comments tend to identify the RCD Applicant Group or MAF as the main likely sources. Regional councils are another funding source identified, given their responsibilities for the development of RPMS’s. Others argue that it is a farmer problem and that they, or more broadly the "agriculture sector", should pay. Another argument put forward is that an equitable framework should be used to apportion costs between various stakeholders (Taylor Baines).

Resources have not been identified for all aspects of the biocontrol programme. These would include its funding, national co-ordination, technical input, multiplication and distribution of the virus, mitigation of undesirable effects, epidemiological studies, monitoring and research. Ideally, there should be an agreement among parties as to who would be responsible for providing each of these resources before the virus is imported.

4.5 Integration of RCD virus with other control measures.

The Application is not clear on how other control measures, discussed in section 2.1, would be integrated with the use of the RCD virus. The virus would, presumably, be the primary means of control. The Application cautions against releasing the virus again in an area within two years of the first release so as to avoid a build up in resistance. If RCD proved to be unsuccessful in an area then presumably the primary means of control would revert to the use of poisons.

RCD is but one potential measure for rabbit control. I believe that apart from a national pest management strategy, RPMS’s are the most appropriate mechanism that currently exists for the delivery of RCD virus. In some regions the RPMS might need to be amended to allow RCD to be used as a control agent.

4.6 Limitations on the control of RCD virus in a programme.

The behaviour of RCD in New Zealand cannot be predicted and while it could remain restricted in distribution it could also spread readily throughout the country in an uncontrolled manner. If the virus was to be released widely in New Zealand it may not be controllable.

4.7 How the short and long term effectiveness of the programme will be monitored.

According to the Application, responsibility for researching and funding the monitoring of the effectiveness of RCD lies with:

  • Regional Councils (monitoring pests for pest management);
  • the Crown (on Crown lands); and
  • the Foundation for Research, Science and Technology (‘public good’).

Table 5.3 of the Application identifies research and monitoring needs for the short, medium and long term.

Wright (1996) has commented that the rabbit is not a national problem in New Zealand and (1) that the estimated national cost of the rabbit as a pest is not high enough to justify an extensive research programme, and (2) responsibility for funding RCD research should be shared amongst those benefiting from gaining knowledge about the disease and from rabbit reductions.

See section 6.1 for DoC’s comments on monitoring requirements.

As part of their regional pest management strategy regional councils have a responsibility to ensure management of the pest, effective implementation and review of the RPMS and monitoring the efficacy of control methods.

If RCD was to be released, research would be needed in order to ensure that an appropriate adaptive management programme for rabbit control could be developed incorporating RCD as an integral component. The research programme would need to be designed to meet the precise requirements of those who intend to use the disease in the long-term and those who need to gain a better understanding of the respective roles of rabbits and their predators in areas of high ecological value.

Conclusion

The legal basis for regional councils having exclusive use of RCD virus in New Zealand is uncertain based on the RCD Applicant Group’s statement that RPMS’s are not appropriate for regulating the release programme. Until this issue is clarified it is doubtful that the potential benefits of RCD can be realised.

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