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 can I be kept informed of what’s going on with the National Pest Plant Accord?

The Ministry for Primary Industries maintains a consultative list, who are provided with regular updates and are sent any consultation material. You can be added to the consultative list by emailing your contact details to

More information about the National Pest Plant Accord is available on the Ministry for Primary Industries Biosecurity website

How did didymo get into the New Zealand river system?

We will most likely never be able to determine exactly how didymo first entered the river system. The most plausible method of introduction was the unintentional transport of microscopic didymo on recreational or industrial equipment from affected areas overseas. DNA evidence suggested didymo was introduced from North America on fishing equipment.  

Why don't we ban seed imports from countries that grow GM crops?

Firstly, it would have serious negative effects in several agricultural industries, including dairying, and would seriously damage and possibly destroy those industries that rely on imported seeds. Secondly, it would still not provide a guarantee to stop all GM seeds.

Many of New Zealand's agricultural industries rely on imported seeds - the price and quality of seeds affects their competitiveness. For example, maize is grown for food and is also an important stock feed in the dairy, pig and poultry industries. Many of the best quality seeds come from countries that grow GM crops, because they are also the world's major seed producers. Banning seeds from those countries would limit access to seeds with desirable characteristics (such as even ripening) and would raise the price of seeds because there are few alternative sources. New Zealand only allows maize seeds to be imported from fourteen countries (Australia, Canada, Chile, the USA and ten European countries). Most comes from the USA and Chile with smaller amounts from Australia and Europe. The USA and Canada both grow large areas of GM maize. Chile allows GM maize (usually imported from the northern hemisphere) to be grown for seed exports. France and Germany grow very small areas of GM maize and are conducting trials of GM maize. The other European countries are not major maize producers.

Are stakeholders expected to pay for the surveillance strategy?

No, developing the strategy is a MAF funded project reflecting MAF Biosecurity New Zealand's over-arching leadership role. However, other stakeholders are expected to directly contribute 'in kind' by shaping the direction and content of the strategy through participation in meetings, workshops and by providing written submissions. Looking further ahead, in future it is envisaged that people and organisations with a role or interest in biosecurity surveillance will begin or continue to contribute directly to surveillance activities, and in some cases these contributions may increase.

Why do I have to connect through ECN?

ECN also provides a 'link' between industry and the New Zealand Customs Service. They have the experience, relationships and support systems to provide a centralised server and manage the required changes to industry applications, through an agreement with MPI.

Can I use glueboards to catch insects?

Yes. Glueboards may continue to be used to control insects. However, placing a glueboard in such a way as to deliberately target a rodent is an offence punishable by a fine or imprisonment.

Please note this information is provided by way of general guidance only and does not constitute legal advice. Parties are advised to seek independent legal advice in relation to particular fact situations.

Do my dogs/cats need separate import permits?

All of your dogs and/or cats travelling together and going to the same transitional (quarantine) facility can share one permit.

Why is painted apple moth a pest?

The painted apple moth poses a serious threat to our gardens, crops, forests, native bush, and the communities that depend on them. The pest is a voracious and indiscriminate eater and destroys plants by eating their leaves. It is considered a minor pest in its native Australia where it and other moths are controlled by orchardists using pesticides. It poses a much greater threat to New Zealand’s horticulture and native forests and the moth has already adapted to native and introduced plants common throughout New Zealand.

Why do I have to clean items that have been in contact with water between EVERY river?

Didymo is hard to detect in its microscopic form, so it is invisible in some waterways. People need to treat all waterways as if they might have didymo. People need to Check, Clean, Dry everytime they use a waterway.