The biosecurity system
The risk of incursions of exotic species has historically been managed by the Ministry of Agriculture and Forestry (MAF) and its predecessors. The Biosecurity Act 1993 set up the framework for managing biosecurity risks. In 2004 Biosecurity New Zealand was set up within MAF to lead and coordinate the biosecurity system. In 2007 it merged with MAF Quarantine Services to become MAF Biosecurity New Zealand. The group has around 1,000 staff in New Zealand and overseas, including scientists, inspectors, vets, investigators, policy makers and legal experts.
Organisms (animals, plants, seeds and micro-organisms) that were not present in New Zealand before July 1998 cannot be brought in without approval from the Environmental Risk Management Authority.
Managing the risk of incursions and spread of exotic organisms also involves central, regional and local government, industry, the public health sector and community groups. The New Zealand public are encouraged to look for any odd plants or animals.
Reducing risk at the source
MAF Biosecurity New Zealand gathers information about emerging biosecurity risks and exchanges it with other countries. International trade treaties and multilateral agreements attempt to minimise risk at the point of origin (for example screening shipping containers and fumigating produce). New Zealand also has processes to reduce risks posed by its exports – for example meat has been inspected before exporting since the early 1900s.
The varroa bee mite is a parasite that significantly reduces the number of bees in a hive. It was first noticed in South Auckland in 2000. Transport operators and truck drivers play a key role in reducing the spread of varroa by ensuring bees don’t hitch rides in cargo moving from the North Island, where the mite is prevalent, to the South Island, where it is only found in Nelson.
Borders are the entry point for pests and diseases. Inspections, quarantines, customs clearance and border patrols aim to prevent them getting into New Zealand. At international airports, uniformed staff, declaration forms, detector dogs, amnesty bins and posters in different languages send a clear message that New Zealand has a stricter biosecurity approach than many other countries. The cabins and holds of inbound aircraft are sprayed with insecticides, and at the international mail centre in Auckland sniffer dogs and X-ray screening help intercept letters and parcels containing organic material.
The chance of accidental introductions through trade has grown. In 1915, 90% of New Zealand’s trade was with Britain and Australia. By the 2000s the volume of trade had grown and the number of source countries was much greater, increasing the likelihood that unwanted species would be introduced in cargo. For example second-hand vehicles from Japan pose a risk of introducing Asian gypsy moth eggs, a threat to the forestry industry. Over the 1990s the number of shipping containers landing in New Zealand ports doubled. In 2007 around 600,000 containers entered New Zealand. It is not feasible to inspect such a large number, so the risk that they contain something unwanted is assessed, taking into account things like country of origin. All high-risk containers are inspected.
Monitoring, eradication and control
MAF Biosecurity New Zealand has monitoring systems close to ports and airports, including traps that attract unwanted species such as moths and mosquitoes. If pests are found, eradication campaigns may be launched, but some have been unpopular due to public concerns about health risks. In the early 2000s aerial spraying was used against the painted apple moth in West Auckland, the Asian gypsy moth in Hamilton and the southern saltmarsh mosquito in a number of locations – leading to public protest in some cases.
If eradication is not an option, slowing or reducing the area of infestation are likely approaches. When didymo algae (Didymosperina geminata) were discovered in Southland in 2004, researchers found that eradication was unfeasible. A campaign was launched, urging waterway users to check, clean and dry their gear to try to stop, or at least slow, didymo’s spread. In early 2008 the algae had spread to many South Island waterways but there was no proof it had become established in the North Island.
MAF Biosecurity New Zealand also runs information campaigns to encourage awareness of known invasive species. Species such as the sea squirt (Styela clava) are more likely to be found early if people involved in marine recreation or work can recognise them and report any sightings.