Frequently Asked Questions

Could didymo spread to lakes throughout New Zealand?

Yes. Although didymo prefers a river environment with clear water flowing over stable substrate at depths sufficient for light penetration to drive photosynthesis, blooms have been found in South Island Lakes. Lake Wakatipu, for example, contains visible didymo on some parts of the lake shore.

How does painted apple moth threaten our forests?

The painted apple moth is quickly adapting to New Zealand and has been found on several common native species already. The pest is a voracious eater, defoliating, and eventually destroying, trees it feeds on. If uncontrolled, the pest could spread throughout our native and exotic forests causing widespread destruction.

Will didymo remain in the South Island or will it move to the North Island?

A didymo Likely Environments Model by NIWA in 2005 showed that most of the highly suitable New Zealand rivers for the establishment of didymo are in the South Island. However, parts of the North Island are also suitable for didymo establishment and growth, particularly in the mountain regions and the central plateau. In 2007 NIWA updated the 2005 model with the Didymo Predictive Maps, which predicts the percentage cover and mat thickness of didymo in all New Zealand river reaches. There is no evidence yet of any spread to the North Island, but further research has shown that didymo has the ability to grow in conditions that emulate the water chemistry of rivers from throughout New Zealand, both the North and South Islands. More information about NIWA’s reports and maps can be found in the Pests and Diseases section of this website.

What kind of signs do I need? Where should they be placed?

A clearly visible sign (or signs) will be required to let people know they are entering an approved Transitional Facility area, and only permitted persons are allowed access. They can be placed where they are most appropriate to your facility (eg entry ways). This will be checked by your MAFBNZ Inspector. An example sign is shown below.

Are fish, eels and other foods taken from lakes and rivers affected by didymo safe to eat?


What are the costs of the various survey options?

Growers should discuss costs with the IVAs, as charges will depend on the circumstances of the production sites to be registered.

What do I do if my consignment is arriving via NZ Post?

Fill in the BACC application (offsite link to and email or fax 09 909 8640 the International Mail Centre.

What is the life cycle of the Varroa mite?
Image of the Varroa Mites Lifecycle stages
Isn't it unlikely you will find all the offspring from this consignment of GM zebra danio fish?

We do have to concede that finding and euthanasing all the fish involved is going to be challenging. Even so, we are attempting the most comprehensive job we can. New Zealand has laws around this and it needs to be clear that there are consequences to illegally importing, possessing and selling GM organisms. In the end we will be relying on good public information in this response.

Where should I take garden waste from the vegetation control zone?

All garden waste from within the vegetation control zone must be disposed of at either of these two facilities:

  • Living Earth Refuse Transfer Facilities, 2 Rosebank Road, Avondale.
  • Waitakere City Council Refuse Transfer Station, 20 Concourse Road, Henderson.

Remember that violating the vegetation control zone is an offence under the Biosecurity Act carrying a penalty of up to 3 months imprisonment or a fine of up to $50,000. For a corporation the penalty is a fine of up to $100,000.