Retrospective monitoring of biological invasions with environmental DNA: Tracing Dreissena mussels and their impact (DreissenaTrace)

• Applicant: Professorin Dr. Laura Epp
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564215715

Biological invasions are among the most characteristic processes of current anthropogenically induced change, causing severe shifts in communities and functioning of ecosystems. Their increasing rate often leads to multiple (successive or simultaneous) invasions, in which the single species cause specific impacts and display dynamics that affect interactions among invaders. In addition, these invasions impact ecosystems that are already experiencing differing levels of other pressures, such as eutrophication of water bodies. Investigating the dynamics of invasions in light of these factors is essential to better understand, manage and mitigate the ongoing processes. A paradigmatic example of such successive and interacting invasions in lakes with different degrees of eutrophication are the invasions of the perialpine lakes with the mussels Dreissena polymorpha (zebra mussel) and Dreissena rostriformis bugensis (quagga mussel). Using this study system, the project will capitalize on the power of environmental DNA extracted from sediment cores to investigate invasion dynamics for each of the species and compare 1) the timing and mode of initial colonization, to determine the role of propagule pressure and genetic diversity, 2) local population dynamics and possible secondary regional spread and 3) ecosystem impacts on differentially eutrophied lakes. These investigations will both investigate general hypotheses on successive invasions and multiple stressors and deliver practical knowledge that is relevant for management and conservation.

• DFG Programme: Research Grants