Research Outputs

Innovative components

Freshwater mussels provide important ecosystem functions and services. Globally, numerous mussels are threatened or extinct. Interestingly, some of the world´s worst invasive alien species are freshwater mussels. In light of the expected more extreme environmental conditions due to global change, it is necessary to determine the abiotic range of occurrences of freshwater bivalves. Therefore, a systematic assessment of the sensitivity of freshwater mussels of European inland waters to environmental factors was performed. In total 493 relevant papers were reviewed, resulting in a database of 8405 data entries on presence-absence of mussel species in relation to environmental factors that are affected by global change.

Findings and Implications to practice

Based on this dataset, we derived sensitivity distributions (SSDs) of European freshwater mussel species for water temperature, flow velocity, water depth, dissolved oxygen levels, and air exposure. Interestingly, the temperature sensitivity of alien mussels (% of potentially absent or not occurring fraction) was found to be higher compared to native mussels. Thereby, we identified the most vulnerable species to global change.

For example, on the right photo, maximum habitat temperature (blue line) of alien species (red line) and native species (blue line) of freshwater bivalve species. The 2.5% and 97.5% confidence intervals (dotted lines). Symbols represent a species family. Therefore, we concluded that European mussels that are already vulnerable and endangered are most sensitive to global change. Therefore, conservation efforts should focus on the species with a high sensitivity to global change. The maximum and minimum sensitivity levels are useful to improve the design of river restoration measures throughout the European continent.