Restoring MANA

Forest and Bird, Volume 17, Issue 2, 1 May 1986, Page 29

Restoring MANA

Legend has ifynat Maori navi avigator Ku upe ‘save Weloe : offshore island itssmamé Mana to contOrate his momentous achievement in » oom rom Hawaiki toeAoteayOa. Since then -., the prestige of the title has been eroded by centu-~-Fies Of misuse; today only.a smattering of remnant ve ion and wildlife.remains. Society Conserva- * tion Officer Terry. Fitzgibbon outlines the way in _ "which mana can bé restored to. Mana, by way of a ) in replanting re 5

ith a bellow and a snort the last Mana Island bull recently stomped down the jetty ramp onto the departing barge. The March muster this year marked the final chapter in the grazing saga of the 216-hectare island; sadly the bullcrammed barge left behind a largely denuded landscape thanks to over 150 years of intensive grazing and cultivation. Mana’s history is marked by exploitive events. Local tribes living on the island in the 1820s were swept off by the Waikato’s Ngati Toa and Taranaki’s Ngati Awa, led respectively by their chiefs Te Rauparaha and Te Rangihaeata. Much of the original vegetation was destroyed prior to European settlement in 1832, but the succeeding decades saw more disappear to make way for sheep and cattle. The chequered history of control of the island continued to recent times. In 1973 the Ministry of Agriculture and Fisheries sank thousands of dollars into turning it into an exotic sheep quarantine and breeding research station. A scrapie outbreak in 1978 required all the island’s stock to be slaughtered and put paid to the station. Since then the Lands and Survey Department farming operation has lost a further $300,000 because of high transport costs. However now in a widely praised move, the Department has just recommended in a draft management plan, a rapid phasing out of farming and the refreshing idea of recreating the island as a haven for rare and endangered species. This will be done by re-clothing the island with plants representative of the region, and opening it up to the public so all Mana’s history — natural and cultural — can be enjoyed. The project is about to get underway and deserves full Society support — not finance but a lot of spadework and public enthusiasm. The worldwide native re-afforestation trend has reached New Zealand's shores in recent years, with Tiritiri Matangi near Auckland providing a successful example of what can be achieved on Mana. Since 1983 this Hauraki Gulf ‘open sanctuary’ has been carpeted with 90,000 trees and shrubs, all of which have been raised from locally gathered seed. In three months alone, some 600 people planted 19,000 trees, pricked out 9000 pohutukawa seedlings and built 130 roosting boxes for the island’s newest inhabitants, saddlebacks.

Mana, a similar sized island, provides an even greater challenge for Wellingtonians as it has only a one hectare gully of coastal forest as well as five hectares of manuka/kanuka clinging against its eastern coastal bluffs. Tiritiri had five times more forest in 1983 and grass covered only 57 percent of the island. Research on Tiritiri has shown that the natural process of regeneration is not enough to suppress invading exotic grasses; hence the need for human intervention. Otherwise regeneration would be extremely slow, the fire risk would be high, and furthermore suitable habitats could not be tailored for introduced endangered species. Already Mana hosts at least five threatened native species: three animals and two plants. They are McGregor’s skink, the gold striped gecko, the giant weta, a fern Anogramma leptophylla and Cook's scurvy grass. Perhaps even more importantly, because it is predator-free (except for mice) and is 2.5 km from the mainland, the island has tremendous potential as a refuge for rare species. There are now very few large rat-free islands around New Zealand's coast. Takahe, little spotted kiwi, saddlebacks, shore plover, tuatara and flax snails are examples which could be introduced in due course. Mana’s seemingly flat appearance from the mainland disguises the fact that there are several steep, east-west running gullies — sheltered catchments suitable for starting to plant nursery trees such as taupata,

ngaio and manuka. Areas still in grass will pose a problem and it has been suggested that small, young cattle might be used as "lawnmowers" because they will not break through fences. Spraying and controlled burning might also be required. Biologists lan Atkinson and Colin Ogle, both Mana enthusiasts, believe a mixed

broadleaf forest of kohekohe, milk tree and kaikomako originally covered the island. This was borne out in a survey by the Wellington Botanical Society which also wants to be involved in the replanting programme. Several Forest and Bird branches have already expressed interest in helping out and because our Pauatahanui project is only a few kilometres distant, the two projects are complementary. What better way to appreciate Wellington’s coastal diversity than a visit to Pauatahanui followed by a boat ride to Mana — still with spade in hand! The new Department of Conservation will be the obvious agency to look after the island which should be classed under the Reserves Act — not administered as Crown land as is proposed in Mana’s draft management plan. Controls will have to be placed on landings to prevent rat infestation, which spell doom to any endangered species. As I left Mana recently while hundreds of black-backed gulls wheeled overhead; two impressions remained: — first, that lots of people had to become involved in revitalising the island — second, the wonderment at discovering an ancient giant weta clinging to shrubland vestiges on an island decimated by decades of misdirected effort. Obviously the wonderment can be extended to many more species for many more people if future efforts are directed towards restoring Mana. #