How to sample mollusc communities in mires easily

The described method presents a substantial facilitation of the processing of samples frommires (and other types of wetlands with substrates of high water content) compared to the very labour-intensive picking of shells by hand. Thanks to this increased efficiency we can process large samples allowing to study qualitative as well as quantitative aspects of mollusc communities in such habitats. In case of petrifying springs the author was able to reduce 12 litres of sampled substrate to a volume of 1–0.2 litres (depending on the tufa content). More than 3000 mollusc individuals were collected per sample from the petrifying springs of highest species richness and abundance of molluscs. In mires without tufa 12 litre samples were reduced to 2–0.1 decilitre (depending on the calcium content in water, which determines mollusc abundance and species diversity). In malacozoologically poor Sphagnum-fens we often get a pure sample of mollusc shells already after the first washing (see Fig. 4). Another significant advantage of the present method is the possibility to substantially reduce the sample volume already in the field