15 September 2009

New tool can detect pollution impact on rivers

There is now a tool that can determine the long-term effects of pesticides on living organisms in rivers and on water quality.

This tool can estimate the harmful effect of pesticides, such as those flushed into rivers and streams from agricultural land, within minutes, said researchers from the Helmholtz Centre for Environmental Research (UFZ) in Germany.

There is now a tool that can estimate the harmful effect of pesticides, such as those flushed into rivers and streams.

“It used to be very difficult to detect which chronic effects occur,” said Dr. Matthias Liess, head of the UFZ’s System Ecotoxicology Department. In their new approach, the Helmholtz researchers exploit the fact that pesticides cause characteristic changes to the composition of the affected community.

“You just need to find out which living creatures, e.g. insects and crabs, are found at a certain point along the river and in what numbers,” Liess said. The authorities responsible for water management usually have such data available, he said.

Liess and his colleagues set up a web application where they can enter this data and evaluate it to show immediately how high the level of pollution is in the rivers under investigation. Users download an Excel table from the http://www.systemecology.eu/SPEAR/Start.html and then enter the numbers of each kind of organism found at each sampling site. Once the table is complete, they can then feed it into the ‘SPEAR calculator,’ and the user enters the region in which they took the samples. The calculator immediately shows what the water quality in the area in question is like. Regional data is currently available for Germany, France, Finland, and Western Siberia, but the system has also undergone testing in the U.K. and in Australia. There is no charge for using the service.

Liess said the authorities can use the calculation results to take suitable steps to reduce pesticide pollution of rivers.

“But our tool can do more than just identify problem areas,” he said. It also indicates where unpolluted stretches of river are compensating for the effect of the pollution. This is extremely important because it can show when conservation methods have been successful. Another advantage of the new tool is that in many cases, complex, expensive chemical analyses will no longer be necessary.

For related information, go to www.isa.org/environment.