New report overviews the environmental impact of nutrients

New report overviews the environmental impact of nutrients

Worsening problems created by excess nutrients in European ecosystems are documented in a report published by the European Environment Agency.

The authors of Nutrients in European Ecosystems say natural lakes, artificial reservoirs, rivers, coastal marine waters and terrestrial ecosystems are all affected to varying degrees of severity by nutrient excesses. In most cases, the damage varies only by geographic region.

Many reservoirs serving essential uses such as public water supplies and irrigation are among the most affected by eutrophication because they are, of necessity, located close to areas of intense human activity. The report says eutrophication is a major issue in still water environments but, even after decades of scientific research, there are very few monitoring programmes in existence.

In rivers, the most widespread pollutant in geographic terms is phosphorus, which results in the development of large quantities of seasonal plant growth, leading to other types of impact such as perturbed oxygen and pH cycles, organic pollution and massive growth of toxic algae. The report also confirms that excess ammonium is present in many rivers. Excessive levels of nitrates, observed in many previous studies, represent a widespread degradation of river water and, locally, nitrate concentrations may prevent human uses of water.

In coastal marine waters, the frequency and geographic extent of eutrophication phenomena are increasing, even in marine areas previously believed to be unaffected.

In terrestrial ecosystems, nutrient impacts appear to be serious because of the uncertainty of recovery of the land-based systems, leading to losses of species and ecosystems.

The application of nutrient reduction policies is patchy, says the report. But the authors found it difficult to assess the effectiveness of these policies because of the general scarcity of data concerning primary causes, emissions and the status of ecosystems. All the necessary datasets are not available at European or national level, and do not even exist at all in some countries. It was only possible to obtain a small fraction of the existing data, and this fraction was insufficient to produce a full assessment.

Nutrients in European Ecosystems has been produced by the European Topic Centre on Inland Waters (ETC/IW) on behalf of the European Environment Agency (EEA). The project was led by the International Office for Water (France) with the assistance of the Water Research Centre (UK), National Environmental Research Institute (Denmark), the Centro de Estudios y Experimentación de Obras Públicas (CEDEX) (Spain), and the European Topic Centres on Nature Conservation and on the Marine and Coastal Environment.

Note to the editor: Further information can be obtained from EEA project manager Niels Thyssen, tel: +45 33 36 71 56, niels.thyssen@eea.europa.eu The report is available in full text from the EEA website at www.eea.europa.eu under "Themes / nature"