Water Framework Directive needs to be modified, say scientists
Researchers at the Helmholtz Centre for Environmental Research (UFZ) in Germany have warned that the pesticides used in increasing cultivation of energy crops will have a negative impact on rivers. In order to counter this effect, the EU Water Framework Directive (WFD) must be adapted to take these developments into consideration. In addition, the German scientists believe that the WFD's priority list of 41 harmful substances to be monitored in Europe's rivers is not sufficient, is partially outdated, and addresses just a fraction of chemical pollution. Furthermore, many of those substances have been replaced by other agents, explains Dr Werner Brack of the UFZ, coordinator of the EU-funded MODELKEY project, which is investigating the key chemicals in three model European rivers. 'For instance, the insecticide DDT is on the list even though it was banned in most Western industrialised nations as far back as the 1970s and is therefore no longer used,' says Dr Brack, pointing out that it is the effect of a substance rather than its simple presence that can tip the balance of an ecosystem. 'From our point of view, it would be better for this important list to set out not just priority standards, but also priority effect. That would enable us to monitor cytotoxic, hormonally active and mutagenic substances without knowing about them in detail in advance. This would make it easier to discover new risk substances with harmful effects and to channel the resources where they are really needed. The authorities would be able to react much more flexibly.' However, chemical pollution is not the only factor to be taken into consideration when assessing the status of river ecosystems: Structural changes, oxygen deficiency as a result of overfertilisation and accidentally imported species also play a role. The EU-funded RISKBASE project is one of the schemes trying to improve risk assessment of human-induced changes to the water/sediment/soil system at the river-basin scale. For instance, the installation of water power stations has a substantial effect on the river ecosystem: Among other things, they will inhibit the growth of aquatic plants in some areas, which in turn will rob the fish population of some of their spawning and foraging ground. While the WFD does take a holistic approach and tries to factor in all of these stresses, UFZ scientists claim that there is a need for further research in order to develop concepts to assess and predict the combined effect of those stresses. According to Dr Michaela Hein of the UFZ, 'there are better assessment methods available in many fields that are just waiting to be integrated into the WFD guidance documents.'
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Germany