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Washington, Apr 29 (ANI): Scientists have been able to detect what they say is an unmistakable warning, a death knell, of the impending collapse of the ecosystem.

A team of researchers led by Stephen Carpenter, a limnologist at the University of Wisconsin-Madison, reached the conclusion after studying signals emanating from a remote Wisconsin lake.

It is the first experimental evidence that radical change in an ecosystem can be detected in advance, possibly in time to prevent ecological catastrophe.

“For a long time, ecologists thought these changes couldn’t be predicted,” Carpenter, a UW-Madison professor of zoology and one of the world’s foremost ecologists, said.

“But we’ve now shown that they can be foreseen. The early warning is clear. It is a strong signal,” he said.

Carpenter said the implications of the National Science Foundation-supported study are big.

They suggest that, with the right kind of monitoring, it may be possible to track the vital signs of any ecosystem and intervene in time to prevent what is often irreversible damage to the environment.

“With more work, this could revolutionize ecosystem management,” Carpenter stated.

“The concept has now been validated in a field experiment and the fact that it worked in this lake opens the door to testing it in rangelands, forests and marine ecosystems,” he said.

In the new study, the Wisconsin researchers, collaborating with groups from the Cary Institute for Ecosystem Studies in Millbrook, N.Y., the University of Virginia in Charlottesville, and St. Norbert College in De Pere, Wis., focused their attention on Peter and Paul lakes, two isolated and undeveloped lakes in northern Wisconsin.

Peter is a six-acre lake whose biota were manipulated for the study and nearby Paul served as a control.

The group led by Carpenter experimentally manipulated Peter Lake during a three-year period by gradually adding predatory largemouth bass to the lake, which was previously dominated by small fish that consumed water fleas, a type of zooplankton.

The purpose, Carpenter notes, was to destabilize the lake’s food web to the point where it would become an ecosystem dominated by large predators.

In the process, the researchers expected to see a relatively rapid cascading change in the lake’s biological community, one that would affect all of its plants and animals in significant ways.

“We started adding these big ferocious fish and almost immediately this instils fear in the other fish,” Carpenter said.

“The small fish begin to sense there is trouble and they stop going into the open water and instead hang around the shore and structure, things like sunken logs. They become risk averse,” he explained.

The biological upshot, according to the Wisconsin lake expert, is that the lake became “water flea heaven”. The system becomes one where the phytoplankton, the preferred food of the lake’s water fleas, becomes highly variable.

“The phytoplankton get hammered and at some point the system snaps into a new mode,” Carpenter said.

Throughout the lake’s three-year manipulation, all its chemical, biological and physical vital signs were continuously monitored to track even the smallest changes that would announce what ecologists call a “regime shift”, where an ecosystem undergoes radical and rapid change from one type to another.

It was in these massive sets of data that Carpenter and his colleagues were able to detect the signals of the ecosystem’s impending collapse.

The upshot of the Peter Lake field experiment, Carpenter said, is a validated statistical early warning system for ecosystem collapse.

The finding has been published April 29 in the journal Science. (ANI)