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.

What independent verifications is there of New Zealand's BSE free status?

In July 2000, the EU Scientific Steering Committee (EU SSC) published the results of a 'Geographical BSE-Risk Assessment' of 24 countries including New Zealand which was classified in Category 1, the lowest risk category (lowest risk being the highest achievable category) along with Australia, Norway, Paraguay, Argentina, and Chile. The assessment rated the 'likelihood' that live cattle could be clinically or pre-clinically infected with the BSE agent. The EU SSC again assessed New Zealand's Geographical BSE risk in 2002 the report published in November 2002 again classified NZ as Category 1.

Under the EU SSC assessment the US and Canada are Category 2, i.e. "unlikely but not excluded." A case of BSE has subsequently been detected in Canada in May 2003.

How long does it take after contamination for didymo to be visible in a river?

A number of environmental factors influence how long it will take for didymo to bloom after introduction to a waterway, or whether it will bloom at all, but the process is not well understood. It seems to vary according to river conditions, in some rivers it is visible fairly quickly and in others it is only visible under a microscope.

Do I need an import permit for my dog/cat?

An import permit is required for dogs and cats imported from all countries except Australia.

Hydrilla - Frequently Asked Questions

Frequently Asked Questions: PDF Link to PDF document (354 KB)

For more information please see Hydrilla page.

Where do the restrictions apply?

Refer to the map and list of streets on the website as above.

When will a ban come into effect on NPPA listed species?

Technically, a ban comes into effect when the plant is determined to be an unwanted organism by the Chief Technical Officer but regional councils do not enforce the ban for the first six months, to ensure that all outlets are aware the plant is banned.

I have heard that certain areas are low risk. If didymo is unlikely to form, why bother cleaning?

Low risk doesn't mean no risk. Low risk areas may not have big blooms but if people don't clean they risk spreading didymo to other waterways. Rivers that are suitable for recreational activities such as fishing and kayaking, also tend to be those that are suitable for establishment of didymo. In its microscopic form it is hard to detect so we need everyone to treat all waterways as if they are affected.

Where was Deformed wing virus found?

It has been found in Waikato and Northland. A sample tested from the South Island was negative for Deformed Wing Virus.

Why should I provide comments on the draft Biosecurity Surveillance Strategy?
  • The draft Biosecurity Surveillance Strategy is a starting point, developed for the purpose of stimulating ideas and encouraging feedback. It is a work in progress, and needs your input to ensure that the goals we set are appropriate.
  • When complete, the Biosecurity Surveillance Strategy will guide the decision making by Government in the area of biosecurity surveillance for the next 10 years. This will be achieved by providing goals and priority actions, so it is important that the strategy meets the expectations of those with a role or interest in biosecurity surveillance. We need your input to make sure this happens.
  • Everyone who will be involved in working together needs to be commited to the goals we are trying to achieve. Without this commitment, progress will be slow or non existent. The widest range of input will ensure that the strategy is one that people with a role or interest in biosecurity surveillance can commit to.
  • The process for monitoring the way the strategy is put into action needs to be appropriate, so all those with a role or interest in the system can have confidence in the monitoring. Your input is needed as to how this should be done.