History

The spirit’s flight

The Cape Reinga-Spirits Bay region of the Far North has great significance for the Maori people. According to Maori mythology, when the spirits of the dead return to Hawaiki, the homeland of their ancestors, they travel along sacred pathways of the Muriwhenua (land's end). The dramatic land- and seascapes of this area are the inspiration for the following photographs and writings.

Magazine

004

ISSUE 004

Oct - Dec 1989

Fishing

Birds of prey

Eagle

Solo traverse

Correspondence school

Spirits bay

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Living World

Last chance for snail

Department of Conserva­tion staff have been making a last-ditch attempt to save a colony of flax snails on the remote island of Motuopao, off Cape Maria Van Diemen. The snails, thought to be a sub-species of Placostylus ambagiosus, number less than ten individuals. Their existence has been under threat by the native rat, kiore, which infests the 30-hectare island. Conserva­tion staff made two trips to Motuopao in October to poison the rats, and believe they have succeeded in destroying more than 90 per cent of the population. Gut analyses of rats on the island indicated that they were eating seabird chicks as well as snails. With the rats' removal, populations of such birds as the black-winged petrel, may be ex­pected to increase. Placostylus is one of two groups of large-sized land snails native to New Zealand (an example of the other is the kauri snail). Three species are recog­nised at present: P. bol­lonsi, which is found only on the Three Kings Islands, P. hongii, which occurs between the Bay of Islands and Whangarei, and has its most vigorous populations on the Poor Knights Islands, and P. ambagiosus, which clings to the extreme tip of Northland, between Cape Maria and North Cape. These snails have a distinctive appearance: 75mm high, tall spired, and, when alive, with a rich brown exterior contrasting with an orange shell aperture. However, most specimens encountered are bleached white in the harsh sand dunes of Spirits Bay, Cape Maria, Tom Bowling Bay and elsewhere. Dating suggests that they have been wiped out over the last 6000 years as sand has invaded flax and forest. More recently the assault has quickened, led now by hungry and careless vertebrates. Pigs and rats have devoured most, while the feet of cattle have trampled others and destroyed habitat. It is unlikely that more than a few hundred live P.ambagiosus remain, most within the confines of the North Cape Scientific Reserve. The idiosyncracies of these beasts do not aid their survival. Devoted vegetari­ans, they seem to frequent the environs of just a few broadleaved plants: flax, native pepper, hangehange, karaka, puriri, etc. Not moving further than 10m/ year (and only on rainy nights) they give a new di­mension to the word 'slug­gish'. Should disaster strike their small copse, there is no way that they would make it to the next one.

Travel & Adventure

New Zealand scientists dive in Antarctica

Results Are Starting to appear from an Antarctic scuba diving project undertaken by New Zea­land scientists over the last few summers at Cape Armitage, Ross Island. The research headed by Dr Chris Battershill (lately of Canterbury University, now of Queensland) had a dual purpose. The first was to examine subtidal ecology in a particularly harsh and unusual environment, and the second was to find out whether any of the marine organisms present pro­duced chemicals with pharmaceutical value. The Antarctic subtidal environment is of interest for several reasons. The water temperature is -1.9°C (dissolved salt depresses its  freezing point by a few degrees). Ice cover for most of the year means light levels are very low, and this in turn prevents most phytoplankton growth. Water clarity is outstand­ing, due both to the absence of plankton and the lack of rivers disgorging sediment into the water. For their diving base the New Zealand scientists use a small, heated but perched over a hole cut through the 2m thick ice. Multiple layers of Antarctic outdoor clothing (the outside summer temperature is around -15°C) have to be exchanged for special 'dry suits'. An outer waterproof layer goes over polypro­pylene and cut fibre undergarments. Air is used to inflate the suit and provide extra insulation,  except in the gloves, so hands always get cold first. Scuba tanks each carry two regulators fitted with a Y-valve. This is in case one regulator freezes up. Antifreeze-filled caps cover the first stage of each regulator to reduce the risk of icing up. Where possible, bulldoz­ers are used to clear snow off the ice surface over an area half the size of a rugby field. These 'windows' allow light to penetrate the ice (which is basically transparent) giving a blue neon light effect. Seals are not uncommon under the ice, but the range of shallow water fish is very limited. Most Antarctic fish inhabit deep water (300m+). At shallow depths (up to 5m), ice has ground all rock faces bare of organisms. Below the ice abrasion levels, rocky surfaces are densely covered with encrusting organisms — ascidians, anemones, tube worm colonies, bryozoans, hydroids and soft corals, but sponges are the most important and striking component of the fauna. Giant starfish feed on sponges and anemones, some of which may reach plate size. The lack of light means that seaweeds, a major component of most hard shorelines, are sparse or absent most of the year, though during summer algae and plankton may bloom briefly in areas where ice melts. Fish have unusual, bright eye pigments to cope with the low light levels. Colours of the organ­isms are more subdued than one would find in New Zealand. Predators seem to be less common than elsewhere, and growth rates of organisms are generally slow. Preliminary results of the search for pharmacol­ogically active compounds suggest some may be present, but the number of species producing such molecules is much lower than in temperate areas. Sponges from other regions have proved to be a particularly rich source of these compounds ­possibly they deter predatory animals and bacterial invaders. The work is continuing.

Science & Environment

Quest for the Kakapo

Here is a timely insight into one of the most extraor­dinary birds which have ever lived. Once thought to be an evolutionary 'missing link' between owls and parrots, the kakapo is fighting a losing battle against the forces of habitat change and predation. Fewer than 50 birds are left: a few on Little Barrier Island; a few on Codfish Island, and perhaps some on Stewart Island and in remote areas of Fiordland. David Butler's book links historical knowledge of the kakapo and its ways with more recent studies of the bird's behaviour and the attempts being made right now to save the species. Many New Zealanders will have heard (courtesy of the National Programme's morning bird calls) the booming of the male kakapo as he attempts to attract a mate. Few will know that the bird is able to keep up this remarkable serenade for 17 hours, at 1000 booms per hour! Many other interesting facts emerge: the moss-green kakapo feathers are unusually warm, soft and fragrant — qualities that made them highly prized by the Maori for use in cloaks; there was once a rare yellow form of kakapo (an 1898 painting compares the two); kakapo feed by using their tongues and beaks like a juice extractor. The book is profusely illustrated, and contains a touching tribute to the kakapo by Gerald Durrell. Durrell lists his 'top ten' experiences with birds (everything from observing Sri Lankan tailor birds sewing their pocket-like nests to being dive-bombed by Arctic skuas), then claims that meeting his first kakapo exceeded them all. Writes Durrell: "If natu­ralists go to heaven (about which there is considerable ecclesiastical doubt) I hope that I will be furnished with a troop of kakapo to amuse me in the evening instead of television. Meanwhile, however, the kakapo is in grave danger of slipping away from us... before we have unravelled the secrets of its strange nocturnal life."

Geography

Earthquakes

Ever felt a tinge of curiosity about earthquakes? This book is not for you. Ever had a moderate but perhaps spasmodic interest in earthquakes? This book is not for you either. Ever had such an insatiable lust for hard information on earthquakes that you salivate whenever anyone even mentions a Benioff variable-reluctance seismometer? OK, relax, this book just might help. Earthquakes is a revised, updated version of a serious book by an expert New Zealand author that includes more than you ever imagined there was to know about seismology. The 22 chapters cover earthquake recording, causes and distribution, tsunamis and volcanoes, prediction, zoning, insurance, buildings, 'earthquakes and the bomb', moonquakes, famous earthquakes and much, much more. Along the way there is plenty of general geology in concise and digestible form, but some of the more specialised seismology chapters ( e.g. Chapter 4, Reading the Records) require sustained concentration. The author's style is not the unrelieved, cold, impersonal and impenetrable stodge of scientists — it's absorbing, lively, even amusing in places. The book is thoroughly illustrated with diagrams and photographs, but, alas, all are in black and white. The arresting cover photos of the 1987 Edgecumbe earthquake left me disappointed when I delved inside. With reader interest in earthquakes activated in the wake of the recent San Francisco shakes, Eiby's discussion of the behaviour of buildings and structures during earthquakes makes informative and timely reading. We learn about the relative effects of resonance and inertia on different types of building, and practical steps that can be taken to safeguard the contents of the home in the event of a tremor. Although the treatment is global in outlook, there is a pronounced New Zealand tilt, with a number of maps, illustrations and photographs giving infor­mation on such topics as the Alpine Fault, earth­quake probability zones, active faults and volcanoes, and the effects of earth­quakes in this country. Eiby provides a concise checklist of New Zealand earthquakes, which, among other things, suggests our earliest quake occurred around 1460 in Wellington, and was known to the Maori as Hao-whenua, the land swallower. As to the future, Eiby claims that most of New Zealand is in a moderate to high earth­quake risk zone, and just because there haven't been many quakes in places doesn't mean that they aren't coming up!

Travel & Adventure

Over the tops

On 26 April, 1989, Michael Abbott stepped into the surf off Farewell Spit, completing the first full-length traverse of the South Island. In 130 days the 29-year-old architect had walked 1600km, crossed the Main Divide 32 times and climbed 58,000 vertical metres — equivalent to seven ascents of Mt Everest.

Living World

The country is my classroom

More than half a million New Zealanders have received their schooling not in square classrooms but in housetrucks, boat cabins, caravans and bedrooms. Most have never met their teachers, but all praise the merits of a great New Zealand institution: The Correspondence School.

Science & Environment

Terror of the forest

New Zealand's forests were once the home of the largest eagle in the world. This normous bird had claws as big as a tiger's, and could strike its prey with the force of a concrete block dropped from the top of an eight-storey building.

Science & Environment

Deep water fishing

A visit to your local fish shop will only confirm the fine print on the supermarket boxes: most of the fish we are eating these days was unheard of a decade ago. Furthermore, we are now exporting these strange-sounding entities (hoki, alfonsino, orange roughy, oreo dory) all around the globe. Fishing has become a major new industry, but the operation bears only a  limited resemblance to the fishing that was practised less than 20 years ago.

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