Invasion of the quagga mussel Dreissena rostriformis bugensis in Germany – processes of spread and interspecific competition

Supported by Deutsche Bundesstiftung Umwelt (DBU) (Invasion der Quagga-Dreikantmuschel Dreissena rostriformis bugensis in Deutschland – Ausbreitungsprozesse und Konkurrenz)

Invasive species are known to cause major threats to biodiversity. The zebra mussel (Dreissena polymorpha) represents a textbook example for an invasive species. It lives in fresh and brackish waters. Approximately 200 years ago this mussel became invasive. To date the zebra mussel occurs almost entirely throughout Europe. By the middle of the 1980th, this species found its way into the USA.
Beside this well-recognized invasion, a new invader – the quagga mussel Dreissena rostriformis bugensis – recently turned up in the USA. The quagga mussel is originally distributed in a small area nearby the Black Sea. Meanwhile invasive zebra and quagga mussels in Northern America caused damage to the amount of 267 million US$, altogether. Furthermore they alter ecosystems and displace other species.
In 2006, populations of quagga mussels appeared in Western Europe and in 2007 in Germany. The invasion of the quagga mussel goes along with the phenomenon of displacement of the zebra mussel in sympatric occurrence.
It is unknown which route the quagga mussels took on their way to Western Europe and Germany, which factors are responsible for the high invasion potential and why it displaces another invasive species.
This project aims to understand the processes of the invasion and the importance of interspecific competition with a combination of experimental and molecular approaches.