The Wilderness of Onoke Spit

Forest and Bird, Issue 311, 1 February 2004, Page 36

The Wilderness of Onoke Spit

JASON ELSWORTH

reports on coastal dunelands in need of care.

he remote Onoke Spit on the wild south Wairarapa coast has only sparse vegetation, no shade and is buffeted by ferocious and incessant winds. Yet the five kilometres of Onoke Spit are an important part of the coastal dune habitat, and home to nesting birds, the threatened red katipo spider and significant plant life. Unlike most dunelands it is still comparatively natural. Unfortunately, compared with preEuropean times, much of New Zealand’s coastal dune habitat is now in a highly modified state. The farming activities of the early settlers, through grazing and burn-off, caused widespread destabilisation of coastal dunes. Introduced species were planted to counter this destabilisation but, although this was successful, it resulted in huge areas of natural dune habitat being lost. Introduced marram grass has now become a major problem, dominating many coastal dune systems. New Zealand’s coastal dunes continue to come under very significant pressure. Farm animals and rabbits continue to graze, and the dunes remain popular for recreational use, especially by motor vehicles. Weeds invade the dunelands and farming artificially increases soil fertility. Again, our beautiful coast is becoming ever more popular for housing development. Onoke Spit is fortunately an unlikely spot for housing. It has largely been unaffected by grazing, and has not been overtaken by marram grass. It therefore remains an area of high botantical value, with the sand-binding plant, pingao, the mat-plant golden scabweed, sand tussock, and at the western end of the spit, towards Ocean Beach on Palliser Bay, the shrub Pimelea urvilleana. As well as being an important botanic site the spit, with its masses of driftwood, is also one of New Zealand’s 19 key locations for the threatened katipo spider. The area of Pimelea urvilleana is host to a local species of moth of the Notoreas genus. The spit is also a valued breeding site for Caspian terns, banded dotterels, whitefronted terns and black-backed gulls. Sadly, in common with many such places, the spit does have one significant conservation issue — disturbance caused by motor bikes and four-wheel-drive vehicles being driven along it. I recently took a walk along the spit, to visit the Caspian tern colony, with Wairarapa conservationist Colin Scadden. Colin has been highly involved in the region’s conservation for over 25 years, and was recently made a Member of the New

Zealand Order of Merit for services to conservation. As we walked he confirmed that the major conservation issue is motor vehicles disturbing the nesting birds and destroying vegetation. There is a Department of Conservation sign at the start of the spit, with a ‘nesting-birds please do not disturb — no hunting, no dogs and no motorbikes’ message. Yet, on the day we visited, we were passed a couple of times by a four-wheel motorbike roaring up and down. A colony of Caspian terns was first recorded nesting on the spit in 1934. Forty minutes’ walking up the spit brought us to this year’s nesting area, and a group of 3040 Caspian terns. Colin Scadden has been banding the nesting terns for the past decade. The main purpose of the banding is to see how long it takes for juvenile terns to return to breed. So far no banded terns have been seen back at the colony. The Caspian terns begin nesting around Labour Weekend and Colin Scadden believes they often have to make up to four attempts, because of vehicle disturbance and blown sand. Unfortunately, we found a number of vehicle tracks in the area the birds appear to have chosen for nesting this year. Restrictions on motorbike and car access are difficult to enforce in such a remote location. Colin Scadden feels if vehicles were to keep to near the lake or sea edge of the spit, then at least the level of disturbance would be reduced. Tony Silbery of the Department of Conservation in Wairarapa says it can be difficult to enforce vehicle access restrictions at such a remote location — DoC relies on locals being their ‘eyes’ in the area. Fencing is another option used by DoC to reduce disturbance; an area of Pimelea urvilleana at the western end of the spit has been successfully fenced. A previous area that was fenced for the Caspian terns, however, has never been used again for nesting. After observing the birds, we turned around and started back down the seaward side of the spit. By now the incessant wind was getting steadily stronger, whipping the sand up and into our faces. At the end of our walk I was left in no doubt as to just how harsh a place Onoke Spit can be. Nesting birds making their way here have a challenging enough time without being disturbed by the activities of people.

— JASON ELSWORTH

is a freelance photographer

and writer who lives in Johnsonville, Wellington.