Archive News

November 27, 2017Although nutrient inputs to Swiss lakes are today much lower than they were before the introduction of phosphate precipitation at wastewater treatment plants and the ban on phosphates in detergents, many lakes are still affected by oxygen depletion – especially in the deeper waters.

November 24, 2017During heavy rainfall, wastewater treatment plants (WWTPs) are often unable to cope with the volumes of water arising, and some wastewater may then be discharged untreated into surface waters. 

November 22, 2017According to a survey conducted by Eawag, around 45 per cent of all actors in the Swiss water sector are concerned in some way with river restoration. 

October 27, 2017In Switzerland – not to mention the rest of Europe and the United States – freshwater fish are falling victim to a deadly disease that is rampant in the summer and dormant in the winter. It is caused by a parasite that thrives in rivers and attacks salmonid fish in particular. Researchers from EPFL, Eawag and University of Bern have come up with a mathematical model for predicting outbreaks as part of a three-year joint research program.

October 16, 2017In a laboratory experiment, Eawag ecologists studied how the pond snail Lymnaea stagnalis is affected by heatwaves, which are expected to become more frequent as a result of climate change. Snails exposed to temperature stress showed a greater investment in reproduction, egg production increasing by 60 per cent on average. 

October 10, 2017A study just published by Eawag scientists shows that gold and silver each amounting to around CHF 1.5 million a year are lost via effluents and sludge from wastewater treatment plants in Switzerland. The concentrations measured do not pose risks to the environment – and recycling would not be economically worthwhile. However, the study also produced surprising findings on other trace elements in wastewater, including rare earth metals such as gadolinium and the heavy metal niobium.

October 5, 2017Single-celled bacteria are capable of mixing water layers in lakes – not directly, by movement of their flagella, but by accumulating locally and thus increasing water density. The heavier water then sinks, creating circular currents. Researchers have now observed this process for the first time not just in the laboratory, but in a natural water body – Lake Cadagno (canton of Ticino).

October 3, 2017Trout that live in stable ecosystems divide the prey spectrum among themselves and develop into specialists. In streams with instable food supply, however, the trout become generalists. Sticklebacks from different evolutionary lineages alter their environment by their feeding habits. This is deleterious to their descendants except they are hybrids. Understanding the interaction between species and environment is important for the effective protection of biodiversity. 

September 27, 2017In order to protect ship hulls and other surfaces exposed to water from algae, molluscs and crustaceans, they are coated with so-called antifouling biocides. Such biocides do not only protect the surfaces, however, but are often leached into the environment and can harm other life forms. 

September 5, 2017Dried-up ponds, culverted streams, contamination with fertilisers and pesticides – the list of adverse effects caused by agriculture to water and waterbodies is a long one. Shortening this list is a major challenge, not only for agriculture but also for society as a whole. Supplying humanity with food is, after all, equally important. At the Eawag Info Day, experts demonstrated that the conflicts between use and protection can be addressed through objective dialogue, transparently stated goals and a broad raft of measures.