Speleological, stalactites, stalagmites, troglobites, chemoautotropic the glossary of the underworld is intimidating. So is a descent thirty feet down on a six-inch-wide cable ladder into a dark, unknown hole in the forest. This is the world of cavers and caving (few of us moles use “spelunkers” and “spelunking”). To the caver, there is no greater joy than a tight crawl in a narrow chasm a hundred feet underground.
For cavers, Hawaii Island offers plenty of crawl space; there are probably more caves on this island than any other place of comparable size on Earth. The island is riddled with hundreds of miles of cave passages. Our caves are lava tubes, and, although often overlooked as such, lava tubes are one of Hawaii’s most valuable and vulnerable natural resources.
One such lava tube is Kazumura Cave, on the east rift zone of Kilauea in the Puna District. In the mid 90’s a group of cavers mapped over 40 miles of passages within Kazumura establishing it to be, by far, the world’s longest lava tube and one of the world’s top ten longest caves. Its linear distance (the straight line distance, end-to-end) of over 20 miles is the longest of any known cave.
Besides its world record size, Kazumura is rich in geologic, biologic, and archaeological features. With its great length, rich resource content, and destructive human impacts, Kazumura is the quintessential Hawaiian lava tube.
The makai section of the tube has been familiar to cavers and archaeologists for many years. Like many of Hawaii’s coastal caves, Kazumura has several culturally significant sites. Archaeologists have identified burial sites, water gathering sites, cooking and habitation areas, artifacts, and what is probably a heiau that has several unique features.
Unfortunately, Kazumura’s cherished sites have been greatly disturbed by cave visitors; many “cavers” in Hawaii are, in fact, artifact hounds, folks who have keen eyes and are skilled at discovering Hawaiiana treasure. From small, finely-crafted fishhooks, to components of elaborate and sacred burials, theft and desecration at Kazumura and other caves throughout the island is a problem.
The cave’s cultural content is not the only element that is impacted by cave visitors. So are the cave’s unique creatures and their ecosystems. Within Kazumura, as in many caves in Hawaii, there exists a unique biological world.
When certain environmental conditions exist, cave-adapted creatures can be found in the dark. The discovery of these troglobitic creatures in Hawaii turned the cave biology world upside down. In adapting to life in the dark zone, troglobites have undergone dramatic evolutionary changes. Mutations such as loss of pigmentation, loss of eyes and vision, and loss of flight were once thought to have taken much more time than was possible on our geologically-young island. The discovery of cave crickets, plant hoppers, thread-legged bugs, millipedes, and spiders adapted for the dark is one of the great stories of Hawaii’s natural history. This discovery helped to transform fundamental ideas in biologic and evolutionary sciences.
Along with cave creatures, there also exists a unique microbial world. Bacteria, molds, fungi, and other tiny life forms exist beneath us and nowhere else; some of these life forms are being studied and have shown promise as potent cancer-fighting agents.
These cave ecosystems are incredibly fragile and are impacted every time a cave is visited. Human impact on cave environments runs the gamut. Some systems are altered merely by the breathing and sweating of cavers, which changes the humidity and atmosphere in the cave section. Other impacts are much more obvious. Recreational cavers write their name in the slime mold that coats the cave walls, or spray paint graffiti or direction arrows on the floor. The Kazumura cavers, in their survey, came across sections of the cave with home rubbish piled high. They found gray water and raw sewage, as unwitting residents use Kazumura as a cesspool. Road improvements, which call for the collapsing” of Kazumura have been planned (and fiercely protested by the Hawaii Speleological Survey). Such impacts affect caves all over the island, especially in the developed makai lands.
Lava Tubes are one of Hawaii’s great natural resources. Recently (mid-2001,) a statewide task force has been established to help draft a cave protection law. These wonderful volcanic creations need our respect, care and protection. Please do what you can to help and please cave responsibly. And remember, watch your head!
If you cave or would like to, please practice good caving ethics: cave only in permitted areas. Cave in small groups, with an experienced caver. Use only battery-powered lights no torches or other burning elements. Don’t take anything, and don’t leave anything (i.e. ti leaves; food crumbs; human waste) behind. Avoid touching roots, molds, and other organisms. Avoid handling cave formations; many are very fragile and break with the slightest touch.
Kaumana Caves, located above Hilo, is excellent to explore. It boasts nearly five miles of passage. If you go, be especially careful not to disturb the mauka section’s troglobitic community. Another appropriate cave to visit is Nahuku, or Thurston’s Lava Tube, in Hawaii Volcanoes National Park. In addition to the lit portion, one can hop over the stairwell at the east end and venture into the dark, undeveloped section. Hawaii Volcanoes National Park offers a ranger-guided tour to a beautiful cave every Wednesday (reservations are required).