New way found to tell when species are threatened

Some researchers say they've developed a new method of determining when species are threatened, and it's a lot sooner than previously thought.

The researchers at Baylor University and ecologists from the University of Maryland, Baltimore County are using this new statistical analysis to measure the impact of human-caused environmental degradation on environmental biodiversity. They say it's more precise than current methods.

That precision has shown that scientists were off the mark about the "tipping point" at which species are threatened.

The new method is called the Threshold Indicator Taxa Analysis (TITAN) and is detailed in the British Ecological Society's journal Methods in Ecology and Evolution.

"This new method addresses what we perceived to be problems with existing quantitative approaches for detecting 'thresholds' in the response of organisms to pollutants," said Ryan King, associate professor of biology at Baylor, who developed the metod with Matthew Baker, assistant professor of geography and environmental systems at UMBC.

"Many types of organisms will suddenly decline or disappear once a threshold level of pollution is reached," he said in a statement. "We were particularly dissatisfied with the lack of sensitivity of existing methods and some of the assumptions required by those methods. This method has proven to be much more sensitive while also being very precise in its estimation of thresholds."

Identifying the tipping points for species is important in protecting them and better understanding how ecosystems respond to environmental changes such as global warming, coal mine leaching, agricultural pollution and runoff from development.

For example, the researchers using the new analysis found that it take development of only 1 to 3 percent of land in a watershed to negatively affect the aquatic life. Old methods would show that it would take 20 to 30 percent.

"This really surprised us, but after carefully examining the data and testing the method using simulations, it became apparent that these declines were real," King said. "It certainly brings to light a strikingly strong relationship between development and degraded water quality in streams, but the mechanisms are not yet clear."

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