The Complex of Mega Mania

Forest and Bird, Issue 297, 1 August 2000, Page 14

The Complex of Mega Mania

NEIL SILVERWOOD

explores a new-found cave system in need of protection.

ega Mania lies ‘in the middle of nowhere’ (somewhere in the west of Kahurangi National Park) and hidden by West Coast bush. Though it is one of New Zealand’s largest and most impressive cave systems, the truly amazing thing about Mega Mania is the date of its discovery. Isolation and rugged bush covering held the cave system secret until 1994. Over the last 50 years many of New Zealand’s ancient limestone cave systems have suffered irreversible damage. The recent discovery of Mega Mania and its relatively pristine state has given us one last chance at properly preserving a large cave system. At the age of 16, and relatively new to caving, I was lucky enough to be on the

first trip into Mega Mania. On a helicopter flight over the Heaphy River area I spotted the massive entrance way. A grid reference was noted down by the local chopper pilot for us. After bush bashing our way through copious amounts of cutty grass and supplejack we discovered the impressive main entrance into the unexplored caves. Over the next three years we explored and mapped out a total of over 15 kilometres of underground passages. For West Coast cavers these were exciting times. This was a dream come true for many of us involved in the exploration. During the exploration we discovered an amazing variety of passages in Mega Mania. Much of the 15 kilometres is made up of young active stream ways and passages recently abandoned by water. Many

of these passages flood after very heavy rain. This only happens once or twice a year. Higher up, well above the flood level, we discovered older cave passages long deserted by the streams which formed them. The only trace left of these ancient streams is a fine layer of dirt, which covers the floor. These age-old sedimentation layers have lain here undisturbed for hundreds of thousands of years. Apart from the aesthetic values the potential scientific value of these sedimentation layers is immense. Each layer of dirt tells its own story about the world above. These innocent looking layers of dirt also hold another treasure, the fossilized remains of many extinct birds. Connecting Mega Mania’s passageways

with the surface is a multitude of large entrances and tomo. These slippery bushcovered holes act as natural traps for wandering birds and animals. This natural, brutal process has been going on for thousands of years. And like Honeycomb Caves,

elsewhere in Kahurangi National Park, Mega Mania has become an ancient bird graveyard. Mega Mania’s 27 entrances contain a variety of bird bone deposits. Little scientific study has been carried out on these sites and their relative importance has yet to be established. Trevor Worthy, a leading palaeontologist, spent a few days briefly examining some key areas. Several different species of birds were identified such as the kakapo, kiwi, snipe, and adzebill. A variety of moa species are also represented. In one section of the cave there are five complete moa skeletons laid out where they died. One of Mega Mania’s other attributes is its bizarre formational sections. In one area of the cave we discovered large arago-

nite spikes protruding from the cave walls and ceiling. (See cover.) These are known as anthildites. Apart from some sections of our marble cave systems they are the only known examples of these underground in New Zealand. In another section cavers discovered a small room filled with crystal pendulums hanging on the tips of flimsy looking straws. These had been formed under water in a calcite-saturated pool. Luckily this room is well protected; cavers must peer through a natural stalactite curtain to see the pendulums. Other sections

of Mega Mania are not so lucky. Officers of the Department of Conservation recently visited Mega Mania and were concerned about the state of some areas of the cave. They considered gating off one of the more fragile sections of Mega Mania. Apart from protecting the particular section in question this would enable DoC to gather information on who is using the cave. Most active local cavers I spoke to were opposed to DoC’s proposal. Personally I believe gates should only be used when there are no other alternatives left. A gate can really detract from the wilderness feeling of a cave. In the case of Mega Mania little study has been carried out on who is using the cave system and as yet we know very little about how much impact people are having.

Mega Mania’s Future Mn recent months the Department of _ Conservation has been working with | local cavers to come up with a practical plan for managing and preserving Mega Mania. This is not an easy task! When I went along on a trip with local DoC staff, we camped in the main entrance of the cave just beyond the farthest point the sun reaches into. During the week we completed several different tasks. Our priority was

to start photographing sensitive areas in the cave and record exactly how they are now. The plan is to return in the future, perhaps in about 10 years and redo the photographs. Then, once the two results are compared, DoC will get an accurate picture of what impact people are having on the cave system. Our other task was to mark out ‘sacrificial’ paths through delicate areas. To mark the routes we used red flagging tape and pegged it down with rocks. We also removed many of the fixed ropes in the cave, which have been in Mega Mania since its discovery. The trip really made me realize the importance of this cave. When we originally explored and mapped out the labyrinth we took little time to really look around. Mega Mania is slowly becoming recognized as a nationally important cave system. Unfortunately the cave is also becoming more popular and its isolated location,

which has formerly discouraged people from visiting, has become public knowledge. Mega Mania will perhaps be the last great cave system discovered in New Zealand and is still very close to its original state. This has given us a good opportunity to preserve a cave system properly. Cavers have now begun working toward gaining formal protection for Mega Mania. DoC is also taking a more active role in managing other valuable West Coast caves. For instance, photo monitoring has been carried out in most major cave systems in the Paparoa National Park, south of Westport. Over the last few years the popularity of caving on the West Coast has soared. Many different recreational groups are using our underground resources. There has never been a better time for DoC to become more involved in the management of West Coast cave systems and, together with local

cavers, we should be able preserve our precious underground resources. NEIL SILVERWOOD is conservation coordinator for the New Zealand Speleological Society.

Fragile Caves

ega Mania is a particularly fragile cave system. People should not attempt to visit the system without a lot of caving experience, according to Neil Silverwood who contributes this article. There are many other cave systems in New Zealand, which are less prone to damage, he says. Mega Mania is also a particularly ‘technical’ cave and requires much rope work. ‘If you are interested in learning to cave or want information on caving its worth joining a club. There are good caving clubs throughout New Zealand, he says. Neil Silverwood began caving 1213 years ago on the West Coast of the South Island. During the last seven years he has been involved in the exploration of several new cave systems. ‘Exploring Mega Mania was perhaps the highlight of my caving career, he says. "The exploration was incredibly rewarding. ‘As an exploration caver I have had a rare opportunity to see caves in their pristine original states. Often I have watched these same cave systems slowly deteriorate as their locations become known and _ they become popular places to visit. I have always had a strong interest in cave conservation and learnt early on how best to attempt to properly preserve new cave passages.