LIFE IN THE SLOW LANE
WHY THE SURVIVAL OF A KIWI CELEBRITY RELIES ON A FRIDGE FULL OF SNAILS IN HOKITIKA
More than a decade after they were stored in fridges while their habitat was destroyed, one of New Zealand’s rarest species still has nowhere to go. It has fallen to taxpayers to keep the species alive, after a mining company’s agreement to pay for the captive programme lapsed. A giant, carnivorous snail species now known as Powelliphanta augusta was discovered in 2003, on a ridgeline near Westport. It occupied a small area on the edge of Stockton mine, then run by state-owned miner Solid Energy. The species once lived wider on the plateau before the area was mined, but was restricted to around 5ha when it was discovered. Its only remaining habitat had been targeted for mining, as it contained high-quality coal used in the steel-industry. After a lengthy legal process, the mine company was given a permit to move as many snails it could find. They were given to the Department of Conservation (DOC) to keep in captivity. Solid Energy paid for the captive programme for 10 years, while the mine would be rehabilitated so the snails could be returned. But when the 10-year period elapsed, in 2016, it was unclear if the restored habitat would keep the species alive. DOC is now paying around $50,000 each year to keep the programme going until 2020, when its future will be reconsidered. The snails are kept in plastic containers in two large cold-stores at the department’s Hokitika office. One hectare of original habitat remains on the edge of the mine, just within the boundaries of the conservation estate. Snails have been reintroduced there and elsewhere on the plateau, but the species has very specific requirements that are difficult to replicate. ‘‘The last little fragment [of habitat] that was on conservation land is still there, but it’s precarious because it’s close to the mine,’’ said DOC scientist Kath Walker. ‘‘Taking the top off the mountain means it’s not catching as much cloud, so we don’t really know if that little sliver of habitat that’s left is going to maintain the snails forever.’’ The future of the snails has been debated within DOC, internal documents obtained under the Official Information Act reveal. They show the programme was almost mothballed this year until experts argued that releasing the snails into the wild would put the species at risk of extinction. Of particular concern is the southern morph of the species, of which there are around 150 left. Five of those southern morph snails were originally taken from the plateau, and are more than 20 years old. ‘‘Early release of all snails would almost certainly mean extinction/ swamping of the southern subspecies and loss of genetic diversity within the species,’’ part of the advice said. The department is considering alternative ways to fund the programme, including corporate sponsorship, the documents show. The ongoing situation has angered the environmentalists who vigorously fought against the snails being moved in the first place. The snail relocation became a major conflict in 2006, with groups such as Forest & Bird and Save Happy Valley turning to court action to stop the snails being moved. At the time, they warned of the possibility the snails would never return to the wild. ‘‘It’s a lesson we should never forget,’’ said Debs Martin, of Forest & Bird. ‘‘We should never take that kind of risky approach on a threatened species. ‘‘We never accepted them going into fridges at all, because that’s not what you do with threatened species. You protect their habitat where they are.’’
It’s a lesson we should never forget. We should never take that kind of risky approach on a threatened species. Debs Martin Forest & Bird
Powelliphanta augusta is kept in plastic containers in two cold-stores at the Department of Conservation’s Hokitika office.