ARTICLE : Pests on Rakiura / Stewart Island

 Pests on Rakiura / Stewart Island.

During our eight days on the island, we spent several of them botanising the bush and walking the tracks in and around picturesque Halfmoon Bay / Oban, and the nearby bays.   We were struck by the beauty and luxuriance of the native plant communities, often with plants new to us, and by the abundance of bird-life.   Kereru, kaka, kakariki, and tui were abundant.   It was obvious to us that the intensive possum- and rodent-killing programme in this, the inhabited part of the island, was of great benefit to indigenous ecosystems.

Tropaeolum speciosum / Chilean flame creeper. Photo: DOC.

Some pest plants and other weeds are being controlled, but more intensive control is required.   BotSoccers Richard and Margaret Herbert were so concerned about the weediness of this part of Rakiura that they wrote to Environment Southland (ES) / Te Taiao Tonga.   In his reply, Randall Milne, Biosecurity Officer – Pest Plants, wrote “that the emphasis to date had been on pest animal control in the Halfmoon Bay area.   This has been driven by SIRCET (Stewart Island Rakiura Community Environment Trust), with support from agencies such as ES and the Department of Conservation (DOC).   SIRCET now have a ‘weed person’, and have adopted areas to carry out weed control and revegetation work.   Chilean flame creeper / Tropaeolum speciosum, and Darwin’s barberry / Berberis darwinii are two weed species of particular focus for the project”.   Richard and Margaret reported seeing Bomarea caldasii which Randall will try to get controlled.

He reports that “for the past five years, DOC, ES and Southland District Council (SDC) have contributed to an extensive programme to control Darwin’s barberry in the Halfmoon Bay area.   DOC has been the major partner in the programme, which is appropriate given the values at risk, and its capacity to access funding for such an extensive programme.   There is considerably less flowering / fruiting Darwin’s barberry now than at the start of the programme … DOC has worked on Chilean flame creeper and Selaginella kraussiana / African club moss … using funds from ES over the past five years.   The level of funding does not appear to have been sufficient to halt the spread of Chilean flame creeper in particular.   We hope that the increased publicity on weeds associated with SIRCET will increase the efforts by landowners to take on this and other weeds on their property”.

In 2006 ES sent a pamphlet about weeds to all Rakiura landowners.   It describes Chilean rhubarb / Gunnera tinctoria, several cotoneasters, holly, African club moss and escallonia.   In the draft Regional Pest Management Strategy, ES is proposing to classify Chilean rhubarb as an ‘Eradication Pest Plant’.   Randall writes that “We hope we have caught gunnera in time to make the brave (or foolish?) claim that we will eradicate it from Stewart Island”.

We wish SIRCET, ES, DOC and SDC all the best in their drive to eliminate pest animals and pest plants and other weeds from the Halfmoon Bay area.   Their work is critical to the protection of indigenous ecosystems there, and all over Rakiura.

Editor