Mike Finlayson: Two weeks, two invasions

Cr Mike Finlayson

Northland has suffered two serious foreign invasions in two weeks.

Not Kim or Donald, but gypsywort and myrtle rust. The first has been identified in Te Paki's Te Werahi lagoon. We are lucky in that this is the only place it's been found, which means we have a good chance of eradicating it.

Gypsywort is an aquatic weed that forms dense patches around the edge of lakes, smothering native plants like raupo. The area is now off limits to the general public, because if it gets spread around then our world-renowned dune lakes, of which we have over 400, would suffer a massive hit.

The seeds can last nearly nine months floating on moving water, and can easily be picked up by ducks, hunters' dogs or gear and moved to another area. This is why it is important to 'check, clean and dry' (CCD).

This fresh water pest awareness campaign, which is being promoted by your regional council and the Ministry for Primary Industries, encourages people to check their equipment and remove obvious gunk, clean off all equipment (boats and motors, diving and fishing gear, including nets, and of course dogs if they've been in the water), and dry for at least 48 hours.

The CCD campaign started on the Mainland, where rock snot (Didymo) was starting to spread. So far there is none in the North Island, and we certainly don't want it. Go to www.mpi.govt.nz/travel-and-recreation/outdoor-activities/check-clean-dry/ and find out how you can help stop the spread of invasive aquatic nasties.

The fact that myrtle rust spores are microscopic means they can easily be spread by wind, insects, birds, by us and our cars and machinery. To say this is a serious biodiversity threat is probably an understatement.

Myrtle rust could not only spell the end of our delicious feijoas and guavas, but, far more seriously, will infect iconic natives like pohutukawa, rata, manuka and kanuka. The implications for our booming manuka honey industry don't bear thinking about.

The role of manuka and kanuka as the primary pioneer plants in regenerating native forest is also at stake. The fact that myrtle rust spores are microscopic means they can easily be spread by wind, insects, birds, by us and our cars and machinery. To say this is a serious biodiversity threat is probably an understatement.

Your regional council, together with MPI, DOC, iwi and scientists, is working to contain it within the two sites in Kerikeri where it has been found. With a huge dose of luck and your help we may be able to stop any further incursion.

If you think you have seen myrtle rust (a bright yellow fungus), please take a close-up photo of it (try not to touch it, as this will increase the chance of spreading it) and another of the whole plant and either call MPI on 0800 809-966 or go to www.mpi.govt.nz/myrtlerust and report it there and find out more about it.
Email mikef@nrc.govt.nz