IN Hawaii - one of the most species-rich places in the world - animal-rights groups and environmentalists are at odds over the killing of feral pigs. The issue illustrates a worldwide problem: the devastating effect nonnative plants and animals can have hundreds of years after their introduction to a new habitat.
The controversy has pitted People for the Ethical Treatment of Animals (PETA) and some native Hawaiian groups against The Nature Conservancy, other environmental groups, scientists, and government agencies.
The first pigs came to Hawaii about 1,500 years ago with native Polynesians. Other varieties came later with Europeans. With no natural predators and lush forests to provide food, the number of feral pigs - domesticated animals that have gone wild - has grown rapidly.
Biologists and environmental activists say the omnivorous pigs act like rototillers, destroying large areas of rain forest and, in the process, causing pollution and erosion. In addition, the wallows they create are breeding grounds for disease-carrying mosquitoes.
Interior Secretary Bruce Babbitt calls feral pigs ``the No. 1 threat to this fragile environment.''
While Hawaii amounts to a small fraction of the United States landmass, it is home to 40 percent of this country's endangered animal species and 35 percent of all endangered plants. Half the native-bird species that existed before human contact has since become extinct, and half of the rest is in danger of extinction.
Hawaii's tropical ecosystems are particularly vulnerable because before humans arrived there was only one species of land mammal - a kind of bat. Plants and other animals evolved with little or no natural defenses.
Fences have been erected to limit pig damage, but the most controversial measure involves snares, in which the animals are caught and eventually die. PETA, an activist group known for confrontational tactics, says the pigs suffer greatly in the process.
``In recent months, scores of wild pigs, goats, deer, and other animals have died agonizingly slow deaths in deadly traps hidden in their forest home,'' states a fund-raising letter sent to members of the animal-rights group, which has also urged a boycott of the Nature Company, one of the corporate supporters of The Nature Conservancy.
Last year, PETA president Alex Pacheco spent several weeks in a remote forest on the island of Molokai, where he and another PETA staff member say they destroyed more than 700 snare traps set up by The Nature Conservancy.
The conservation group, which has purchased millions of acres of land around the country to preserve them from development, says it is willing to try other means to control the feral-pig population. But it maintains that, especially at higher elevations, snares are the only method to prevent widespread environmental damage. Many experts agree.
``There is no question that exotic species - feral pigs among them - have to be removed from natural habitats to avoid endangerment and extinction,'' asserts Thomas Lovejoy, a senior official at the Smithsonian Institution and a science adviser to Mr. Babbitt on setting up a new ``National Biological Survey'' to protect species habitat and biodiversity.
In a National Academy of Sciences paper, Stanford University biologist Peter Vitousek wrote: ``Grazing and browsing animals affect islands in such pervasive ways that it is difficult to see how native ecosystems can be protected unless they are eliminated.''
Though some have done so reluctantly, most environmental groups support the use of pig snares by The Nature Conservancy, as well as state and federal land-management agencies. These include the Sierra Club, Earth Island Institute, the National Audubon Society, Defenders of Wildlife, and the Rainforest Action Network.
Noting that Hawaiian rain forests include some 10,000 species found nowhere else on Earth, representatives of the Hawaiian Botanical Society, the Conservation Council for Hawaii, the Native Hawaiian Plant Society, and the University of Hawaii Environmental Center also voiced support for ``the judicious use of snaring, fencing, hunting, and live-trapping as essential tools for conservation in the face of Hawaii's desperate extinction crisis.''
To develop more acceptable means of controlling feral pigs, The Nature Conservancy recently formed the ``Animal Control Research Consortium.'' Participating organizations include PETA, the Hawaii Department of Land and Natural Resources, the Humane Society of the United States, the National Park Service, and the Fish and Wildlife Service.
``We want to do everything we can to accelerate the research for new methods that are both humane and effective,'' says Alan Holt, director of stewardship for The Nature Conservancy of Hawaii.