- 5.1 Impacts on indigenous flora & fauna and natural communities
- 5.2 The Risk to Human Health
- 5.3 The relationship of Maori and their culture and traditions with ancestral lands, water, sites waahi tapu, valued flora and fauna and other taonga
5.0 The Effects, Positive and Negative, of RCD
5.1 Impacts on indigenous flora & fauna and natural communities
The potential ecosystem impacts of the introduction of RCD was a matter of grave concern to ecologists, conservationists and many members of the public. The complexity of natural ecosystems, the unpredictability of the impact of RCD and the dearth of hard data combined to create a climate of uncertainty and demands for caution.
The CVO’s report (section 5.2.2) summarises the range of ecological impacts that may follow the introduction of RCD. The scale of these impacts is likely to be directly proportional to the scale of rabbit mortality.
While the long term benefits of the removal of rabbits from the New Zealand environments where it is having severe ecological and environmental impacts were conceded by most, the short-term negative impacts were most feared and reassurance that these would at least be managed was demanded by many.
In section 6.1 of the CVO’s report, there is discussion of the strategies that would be necessary to ameliorate the negative impacts of the sudden removal of rabbits from the vulnerable ecosystems.
I have concluded that in the long term, the reduction of rabbit numbers has significant benefits to a range of land and water values and that these benefits outweigh any negative long term effects. If RCD were successful as a control agent, the predator population would be likely to adjust to prey availability. In the short-term, the negative impacts are potentially serious and would require active management. The contingency planning undertaken by the Department of Conservation (DoC) is predicated on a scenario in which rabbit mortality is high and widespread.
It is unfortunate that some monitoring of the impacts of large poisoning operations or rabbit population crashes for other reasons has not been undertaken. It is difficult to accept that the impact of RCD is so much greater than the impacts of events such as these which have been largely ignored to date unless the impact of RCD is more widespread than these events.
However, even if DoC’s estimates are correct, the annual cost of about $4 million for 3-5 years would be likely to be exceeded by the benefits many times over. Unfortunately, the probability of DoC’s scenario being achieved seems low.
5.2 The Risk to Human Health
There appear to be three elements in assessing the risk of RCD to human health:
- biological hazard of human infection by the RCD virus in the form in current circulation or as the result of mutation;
- exposure hazard;
- comparative risk.
| The CVO’s report (section 5.6.1) summarises the available evidence that the RCD virus does not affect man even though one case of temporary seroconversion is recorded. Negative evidence such as this is less than satisfying if one wants absolute evidence that the virus does not infect humans but this level of reassurance is rarely, if ever, attainable. In the end, I concur with Dr Donald Burke’s conclusion | ||
| "....the risk of a significant adverse epidemiological event is very low, but it is not zero." | ||
Given the intended use of the virus, there would be occupational exposure to infected material but it is very unlikely that there would be widespread exposure of the general population. This is of some significance in considering comparative risk.
Burke has cited examples of 3 viruses which have caused global or localised epidemics in humans and 7 similar examples in animals. Nineteen of the 20 viruses were RNA viruses like the RCD virus. There are 23 genera of RNA viruses recorded in humans and animals in New Zealand including examples of the viruses discussed by Burke. Thus people in New Zealand are exposed to a background risk of adverseevolution of any one of this group. Further, we make little effort to control the movement of people and the RNA viruses they carry, this being an element of the background risk.
In my view, the risk to humans of the introduction of the RCD virus does not add significantly to the background risk we now accept. The proposal by the Ministry of Health that the standard of proof of safety required should be comparable to that of a new vaccine or drug which is to be directly administered is an unnecessarily high standard.
5.3 The relationship of Maori and their culture and traditions with ancestral lands, water, sites waahi tapu, valued flora and fauna and other taonga
I would like to express my gratitude to Te Puni Kokiri and the Applicant Group for arranging and attending the consultation hui at the nine locations and for the Te Puni Kokiri records of the hui.
While it can be concluded that consultation with Maori did not reveal issues or concerns which had not been raised in the Application and/or public consultation, the Maori issues and concerns assumed particular significance given their Kaitiakitanga responsibilities.
The CVO’s report has summarised the matters of concern to Maori. I believe the decision is consistent with their wishes.
Contact for Enquiries
Manager, Strategic Science Team
MAF Biosecurity New Zealand
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0115
Fax: +64 4 894 0731
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