01:00 AM EST on Wednesday, March 8, 2006

Congress is debating whether the Endangered Species Act should be modified. Since 1973, the law has stood as part of American environmentalism's Holy Four. The National Environmental Policy Act (1969), the Clean Air Act (1970), and the Clean Water Act (1972) have been periodically revised over the years, so some in Congress are asking why the Endangered Species Act shouldn't also be. They have a point; nothing in legislation should be held sacred. Yet care must be taken in addressing this act.

This law sets strict penalties on the killing of endangered species of animals and plants, and it gives the government broad authority in regulating land and water use to protect species' habitat and feeding areas. The authority, which pins survival of species on preserving their ecosystems, has been a key factor -- along with changes in land use -- in the return of many species to areas where they had been absent for decades, if not centuries.

New Englanders over the last 30 to 40 years, as fields have reverted to forest, have witnessed growth in the populations of white-tailed deer, wild turkeys, black bears and other species. Some of these once rare creatures, such as Canada geese, are now in certain places even considered nuisances.

Elsewhere in the country, the problems have been more serious. In the West, mining and timbering interests say that they have been badly hurt by restrictions related to species' habitats; the spotted owl in Northwestern old-growth forests is a celebrated example. California Congressman Richard Pombo, chairman of the House Resources Committee, is promoting changes in the Endangered Species Act to compensate landowners for losses produced by compliance with the act. There may be cases in which such an approach is justified, and judicious modification of the act could go a long way toward diminishing some of its harsher economic impacts.

Still, the Endangered Species Act has been remarkably effective. Virtually all the species it has listed as endangered have seen their numbers stabilize or increase. Much of the United States has become an ecologically healthier place than it was in the 1960s for wild creatures and plants, thanks in great part to this act.

The bald eagle, lately removed from the Endangered Species List, is an example. By the '60s, owing to DDT's use as a pesticide, the bird was almost extinct in the lower 48 states. Then, DDT was found to interfere with raptors' reproduction, so its use was discontinued. Now the bald eagle is common in much of America -- it sometimes even appears in southeastern New England. And all eagles, falcons, and hawks have benefited from the elimination of DDT from the environment; most of these species have gained numbers.

Legislation as old and important as the Endangered Species Act may require tweaking. But this law has been a triumph, and should therefore be preserved.