In a new study, scientists have taken a page from the social science handbook and used leading indicators of the environment to presage potential environmental disasters.

The study, by two ecologists and an economist, suggests it may be possible to use nature's leading indicators to avert environmental disaster.

Ecosystems worldwide - lakes, ocean fisheries, coral reefs, forests, wetlands and rangelands - are under constant and escalating pressure from humans and many are on the brink of collapse, according to Stephen R. Carpenter, a University of Wisconsin-Madison professor of zoology and an author of the new study.

"It's a big problem because they are very hard to predict. It is hard to get a handle on statistically," said Carpenter of what ecologists call "regime shift," a disastrous change in the way an individual ecosystem functions.

In the new study, Carpenter, Reinette Biggs of Stockholm University and William A. Brock, an economist at UW-Madison, used northern Wisconsin's sport fishery as a laboratory to see if leading indicators of ecological collapse can be detected far enough in advance to avert disaster.

"The answer is 'yes' if the policy interventions can be swift and 'no' if there are delays," said Carpenter of the study's results.

The researchers looked at two major threats to the fishery: overfishing and habitat destruction caused by lake home-building and the loss of trees that would otherwise fall into the lake and provide habitat for sport fish.