Ghost trees, who you gonna call?


    As kids on long drives to summer holidays, we used to count ghost trees.

    Singing along to Abba or the Carpenters, eye-spying or counting sequential number plates were possibly less macabre, but nigh-on half a century later, not as memorable.

    Dutch elm disease swept through the UK during the 1960s and 70s and by the time our little Austin Princess was winging its way from Stoke-on-Trent to the sandyfloss and sticky rock delights of Saundersfoot or Woolacombe, more than 90 percent of UK elms – some 25 million trees – had been lost. 

    And that meant the landscape was punctuated by stark, white-grey giants, their bare limbs often stretching 40m into the air, testament to mankind’s inability to fight off an attack from a rogue fungus.

    Those ghost trees were the first thing that sprang to mind on Monday when I took a phone call from an Auckland Council plant pathogens adviser, who told me that another rogue fungus – myrtle rust – had been found on Waiheke. A bit of further digging, and what had actually transpired was that the disease branded “the pinnacle of pathogens” had been found on Aotea Great Barrier six days ago and the council was swinging into action – Waiheke’s first infection had actually been logged months and months ago with the Ministry of Primary Industries, and this was the first time anyone connected to the Hauraki Gulf had taken it upon themselves to be proactive about it.

    So why the worry? Since arriving less than five years ago from spores blown across the Tasman, myrtle rust has spread from the Far North as far south as Canterbury. It attacks and kills some of the country’s most precious (in all senses of the word) native species – mānuka, pōhutukawa, rātā and ramarama – as well as exotic commercial species like eucalyptus and feijoa.

    Most research into its impact has concentrated on four areas: honey, erosion, Carbon sequestration and the social effect of Māori losing taonga trees. A 2019 MPI report reveals the money side: over 20 years, myrtle rust could cost the country between $52 million and $397m. The estimated damage of the mean scenario (ie $157m) is the sum of $49m of lost profits from honey production, $17m representing the value of lost sequestrated carbon, and $91m representing the value of avoided erosion.

    In cold, hard terms, that paints a harsh economic picture.

    But what’s at risk here isn’t just dollars and cents. In Australia, where the disease first appeared in 2010, it took less than a decade for species such as native guava and brush turpentine to go from having no conservation concern whatsoever to finding themselves on the critically endangered list. A University of Sydney report (which followed incredible work from Kiwi and Australian scientists to map the entire billion-letter code for the myrtle rust genome) worried some species were “now on the verge of extinction”.

    Although the $28m to be pumped into fighting kauri dieback that was announced at this year’s Budget was deemed underwhelming (and around only a third of what’s actually required) by grassroots organisations such as Forest & Bird, it was still a fighting fund.

    The battle against myrtle rust seems to have fallen off the radar (as evidenced by it taking nearly a year for Waiheke to find out about its outbreak and by the fact the government seems to be relying on the citizen science website to track its nationwide spread).

    Here on Waiheke, we have precisely the sort of people who can – and more importantly, want to – swing into action when our natural surroundings come under threat. Isn’t this precisely the sort of thorny issue a group such as The Waiheke Collective was set up to tackle? And just look at the clamour when kororā are at risk.

    Although there is no cure for myrtle rust yet and its airborne-spores method of dispersal means it’s a tricky bugger to contain, there are plenty of ways in which we can change our behaviour to help prevent its spread. The woman who called from the council on Monday promises that as much information as she can gather will be available for us to publish in next week’s Gulf News, so watch this space.

    It’s somewhat frustrating that MPI – usually so gung-ho about biosecurity if it affects a cash crop, dairying or a banana in your carry-ons – wasn’t so proactive months ago, but in the meantime, maybe this is an opportunity for Waiheke to turn to some of its own expertise.

    After all, the chance of losing our Christmas-red, pōhutukawa-fringed coastline should mean consensus between those who see themselves as kaitiaki of the island’s environment, flora and fauna, those who simply enjoy walking our beaches and those looking after the tourism-enticing “brand Waiheke”. 

    And surely none of us wants an island ringed by ghost trees. • James Belfield

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