Keeping watch

New Zealand maintains a list of almost 15,000 unwanted plant, animal and marine pests and diseases. Learn why we want to keep them out and how we do it.

The risks

Unwanted pests and diseases (organisms) can damage New Zealand's economy, environment and way of life.


They can weaken earning potential and introduce new costs by:

  • reducing the health and productivity of commercial animals or plants
  • limiting New Zealand's access to export markets
  • degrading wilderness areas so they're less attractive to tourists
  • requiring costly control programmes.


They can endanger native species and upset delicate ecosystems by:

  • competing for food and water
  • feeding on native plants or animals
  • causing outbreaks of disease
  • clogging waterways or causing land erosion.

Way of life

They can change things New Zealanders take for granted by:

  • stopping us from moving freely around the country (travel restrictions)
  • destroying wilderness areas
  • spoiling our waterways
  • reducing animal, plant and fishing stocks.

Pests can also attack humans or infest homes, while some diseases can transfer to people.

Types of pests and diseases

Biosecurity threats come in many forms:

  • Plants can overrun crops, native forests, waterways and marine environments.
  • Bugs and parasites can attack people, animals or plants, and spread disease.
  • Larger animals can feed on native species and spread disease. They can also severely damage and modify soils, landscapes and seascapes.
  • Saltwater invaders can interfere with wild species.
  • Pathogens make people, plants or animals sick, or can kill them.

Protecting New Zealand

New Zealand's biosecurity system has 3 interlocking layers of protection.

1. Pre-border – before cargo departs for New Zealand

Regulations and offshore inspections help minimise the risk of unwanted arrivals.

  • Some items are banned from coming to New Zealand.
  • Others must be treated before coming here.
  • MPI inspects overseas loading facilities and some cargo before it's shipped.

2. At New Zealand's border

New Zealand's airports, seaports and transitional facilities are closely monitored.


  • Passengers fill out biosecurity declaration cards.
  • Detector dogs are used to identify risk goods on people and in luggage.
  • High-risk or suspicious items are x-rayed.


  • Accredited persons check cargo at transitional facilities.
  • Suspect containers or packages are treated for pests.

3. Post-border – within New Zealand

We're always watching for new pests or diseases and preparing to handle an outbreak.

  • New Zealanders report more than 10,000 suspected pests and diseases every year.
  • Of these, about 750 lead to a formal investigation.
  • Every commercially slaughtered animal is inspected for disease.
  • 13 surveillance programmes watch for specific risks.
  • A network of labs provide world-class diagnostic testing.

If there's an emergency outbreak of pests or diseases, 150 organisations and 55,000 people are ready to respond through the National Biosecurity Capability Network.

Who to contact

If you have questions about information on this page, email

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