New Zealand's Ministry of Agriculture has nixed a plan to let loose a deadly virus to attack the country's exploding populations of rabbits. Last week the government issued a statement saying that not enough is known about rabbit calicivirus disease (RCD) to warrant unleashing the virus at this time. The decision puts New Zealand on a different course from its antipodean neighbor, Australia.
Australia plunged into a full-scale test of the RCD virus in the fall of 1995--earlier than it had intended--after the virus escaped to the Australian mainland from an experimental station on Wardang Island, off South Australia. Once the virus began to spread, Australian officials decided to introduce it in hundreds of locations around the country to try to wipe out populations of rabbits, originally introduced from Europe, that have decimated native plants and the animals that feed on them.
New Zealand has been considering launching a similar viral attack on its rabbits. But the government has now decided to wait and see how the RCD story unfolds in Australia (Science, 10 January, p. 154 ). "We cannot go and retrieve the virus if we are not happy with its behavior," says agriculture official Peter O'Grady. Although Australian researchers did not find any evidence of transmission from rabbits during tests on dozens of other species, O'Grady says scientists still have "a poor understanding" of RCD. He also says that there is significant uncertainty as to how effective the virus would be in New Zealand, which lacks some insects that are believed responsible for spreading the disease in Australia.
The New Zealand decision is being hailed as a victory by a U.S. virologist who has opposed the Australian program from its beginning. Alvin Smith of Oregon State University in Corvallis, an expert on caliciviruses, has maintained that not enough is known about the virus or its potential for moving into other species. "The warnings I've been giving have been heard by the New Zealand people, I think," he says. Smith's opposition to the plan in New Zealand was backed by several environmental groups and other organizations.