NZ Herald editorial: Unwelcome pests need a firm response

This Chilean Needle Grass. Photo / Supplied

Just before Christmas, biosecurity investigators discovered an outbreak of a plant pest called Chilean needle grass on a North Canterbury farm. Steps were immediately taken to destroy the infestation which, if left unchecked, could reduce crop yields and cause animal welfare problems.

Its barbed seeds can work their way through animal hides into flesh and bone, leaving young animals in particular weak and vulnerable.

The discovery was the 17th known infestation of the plant invader and an unwelcome reminder that New Zealand's primary-based economy is particularly vulnerable to pest incursions.

This summer, teams of biosecurity experts are also trying to contain the spread of the dairy disease, Mycoplasma bovis. The bacteria has been detected in stock on 12 farms, from Southland to Hawke's Bay. More than 3500 cattle have been culled.

Marine inspectors have their hands full trying to stop the spread of invasive ocean pests. Fanworm threatens the ecology of some harbours and a nasty from Australia called droplet tunicate has been discovered in Mahurangi Harbour, Sandspit, and Oakura Bay on Waiheke.

In the South Island, the spread of wilding pines is proving a costly blot on the landscape. Millions is being spent on eradication and research to devise more effective control measures.

Myrtle rust spores have infected more than 100 properties from Northland to Taranaki.

The other high profile biosecurity threat causing a headache is the pathogen killing kauri. One leading scientist says the disease has spread so rapidly with the help of public apathy that the species could be entered on the international list of plants facing extinction.

That such a majestic and precious asset could be wiped out would be a tragedy and a blow to New Zealand's environmental reputation.

New Zealand is continually dealing with an army of biological invaders which could undermine the economy. The relative newcomers mentioned here highlight the need to remain equipped to deal both with common pests and diseases and vigilant in responding to novel incursions.

Our environment permits the rapid spread of unwanted organisms, generally at a speed which outpaces our ability to contain them. Promising developments are emerging in science which could turn the tide but progress in genetic science and the formulation of safer and more efficient herbicides is cautious.

Minister for Biosecurity Damien O'Connor says he is making the issue his highest priority.

He is considering identifying properties with Mycoplasma bovis and looking to toughen restrictions on forest visitors to save kauri from disappearing. These responses are appropriate.

The kauri forests are treasures which, having been spared from the axe, would be criminal to lose through inaction.

The valuable primary sector likewise requires protection, at the border and inside the farm gate. With exports projected to pass $41 billion by June next year, pest and disease threats need to be met with an effective and firm policy.