Primary productivity and climate change in Austrian lowland rivers.

There is increasing evidence of water temperature being a key controlling factor of stream ecosystem metabolism. Although the focus of research currently lies on carbon emissions from fluvial networks and their potential role as positive climate feedback, it is also important to estimate the risk of eutrophication streams will be exposed to in the future. In this work, a methodological approach is developed to create a scientific basis for such assessment and is applied to two Austrian lowland rivers with significantly different characteristics.

Assessment of instream foam formation and quantification of foam in effluents.

Although the foam formation on surface waters nowadays is not comparable with the foam "mountains" in the 1970s, it still is an issue of water quality concern. A drawback in the discussion is the lack of methods to assess instream foam formation and foam emitted by point sources. Foam formation on a transboundary river in Austria led to an intensive study resulting in two parameters to quantify instream and emitted foam.

Foam in the aquatic environment.

Foams are ubiquitous in the environment, commonly seen as discoloured patches on streams, rivers, lakes and sea water. They often are assumed to be anthropogenic in origin as they are aesthetically unpleasant, yet they frequently appear in pristine environments indicating a natural origin. In contrast to "hidden" chemical pollution, e.