Workers poisoning willows at the Para Swamp between Picton and Blenheim last week discovered a hidden grove of kahikatea trees.
Marlborough Fish & Game field officer biodiversity officer Rhys Barrier and contractor Dave Barker of Habitat Restoration and Creation found roughly 20 kahikatea, up to a metre in diameter.
"It is pretty awesome," Mr Barrier said.
"Some would be well over 100 years old."
Scattered lines of the swamp conifer had been found in the swamp before but this was the first discovery of a significant grove, alongside an original channel of the Tua Marina River.
A wetland restoration project at the Para Swamp between Blenheim and Picton shows conservation hand-in-glove with gamebird hunting, says Fish & Game New Zealand Marlborough field officer Vaughan Lynn.
Aerial poisoning of willows choking the 120ha wetland was about half-way through, Mr Lynn said. Helicopter poisoning started five years ago and the dead trees were starting to collapse and be replaced with native species.
Helicopter spraying cost about $400/ha compared with about $8000 for hand-drilling and injecting and achieved a 95 per cent kill, he said. Any willows not killed were poisoned by hand, along with buffer strips alongside SH1 and blocks where aerial spraying was planned.
Mr Lynn hopes to poison the last of the willows this summer and autumn and to start digging a matrix of waterways and islands as a habitat for birds including mallard ducks and native bittern, crake, grey ducks, grey teal, shoveller ducks, paradise ducks, pukeko and little black shags. However, mid-summer rain meant this was unlikely.
Different areas of the swamp were being managed in different ways, Mr Lynn said. For example, an area of native sedge and raupo was being managed under an agreement with the Department of Conservation, which contributed $1800 a year to its protection in return for an agreement that the ground there be left undisturbed.
Long-term, Fish & Game aimed to encourage public access by building walkways and perhaps a visitors' centre, Mr Lynn said. People should be able to take a 15-minute walk along the bush-lined Tua Marina River which flowed through the swamp past native trees, some planted and cared for by pupils of Queen Charlotte College in Picton.
New Zealand Gamebird Hunters' Association Marlborough member, Russell West, said restoration of the Para Swamp meant more to hunters than providing more birds to shoot.
Accessible wetlands around the country were being drained and intensified into farming and forestry, he said.
"I enjoy taking my boy to the Para Swamp and whether he shoots one duck or two ducks, it's been a good day because he has enjoyed the environment."
Mr West had talked to German tourists photographing the wetland in the mist who described the spot as beautiful.
Like a Lord of the Rings movie setting, they said.
"It's far nicer than the logging blocks in the background," he said.
Mr West is excited about future plans to control stoats, ferrets and rats which would benefit ducks and other wildlife living there.
Nelson-Marlborough Fish & Game manager Neil Deans said many people had tried to drain the Para Swamp and failed.
In 1906 the Marlborough Express reported that Commissioner of Crown Lands, Mr F. Stephenson Smith, said draining the swamp was out of the question after surveying showed there was only a two foot (60cm) drop between its southern end and junction with the Wairau River.
Originally the Para was a flax and carex wetland with scattered stands of kahikatea, swamp maire, lowland ribbonwood and areas of raupo, Mr Deans said. Aerial photos showed in the 1940s there was only a handful or willows in the swamp where once flax was harvested and kahikatea milled.
Nelson Marlborough Fish & Game owns or manages 105ha of the 120ha Para Swamp, the largest lowland wetland in Marlborough.
In 2010 the NZ Game Bird Habitat Trust committed $95,000 over five years to restore the wetland. Support has also come from the Marlborough District Council, government biodiversity fund and generous individuals.
● To attend the open day at the Para Swamp on Saturday meet at the Fish & Game billboard northern end of the wetland or contact Vaughan Lynn, 027 222 5928
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