Biodiversity

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Aquadivers II

Invasive species

 

Aquadivers II

Relationships between genetic diversity, environmental heterogeneity and species diversity are poorly known, and empirical data and theory development are urgently required. Biodiversity is a function of genetic diversity and environmental heterogeneity and alpine aquatic habitats have much of both: steep elevation gradients and inclination-dependent local climates that range from arctic-alpine to Mediterranean create an unusually heterogeneous environment that requires a diverse range of local adaptations at small to very small spatial scales. Genetic diversity in postglacial systems depends on the distance to glacial refugia, and the Swiss Alps have been colonized by lineages from Danubian, Mediterranean and Atlantic refugia. As a result, the Alpine region of central Europe is unusually rich in aquatic biodiversity, and Switzerland is unique because it harbors the distinct evolutionary diversity of each of Europe’s four largest drainage systems: Rhine, Rhone, Po and Danube. Within each system, Swiss aquatic habitats range from alpine glacier rivers and ice-covered lakes to low-elevation lakes and rivers. Because many of these habitats were inaccessible before deglaciation (14-10kyr bp), much of the ecological diversity of aquatic organisms is young in evolutionary terms. The combination of colonization from several genetically distinct glacial refugia on the one hand, and recent ecological diversification on the other hand, makes Swiss aquatic biodiversity globally unique. Aquatic biodiversity is being lost rapidly in Switzerland, yet the causes of decline are rarely understood. Climate change, changes in nutrient regimes and habitat loss are primary factors that affect species diversity worldwide, and it is likely that these are main causes of diversity loss in Switzerland. However, how and how rapidly these man-made changes of the environment contribute to biodiversity loss in Switzerland is not well understood. Even less clear is how to predict changes in biodiversity, how to optimize management practices of aquatic ecosystems to maintain biodiversity, and how to remediate endangered aquatic biodiversity in the face of rapidly changing environments.

During the year 2009 the project focuses on parasite community structure of ecologically diverged whitefish species (Anssi Karvonen) and genetic structure and diversity of freshwater isopod Asellus aquaticus (Kirstin Kopp).

Disciplines: Biodiversity research, Genetics, Freshwater Ecology, Systematics

Keywords: adaptive diversity, genetic diversity, functional diversity, trophic interactions, isotope analysis, daphnia, periphyton, freshwater snails

Contact person:  Anssi Karvonen, Kirstin Kopp

 

Invasive species

Future distribution of the invasive Quagga mussel in Switzerland

The quagga mussel Dreissena bugensis is highly invasive in North America and Europe. It has already been found in the Upper Rhine at Karlsruhe and most likely, it will be invading Switzerland in the next few years. In other regions, where this mussel has already spread, it is known to have a strong negative impact on ecosystems, biodiversity and socioeconomics. Aim of our project is to provide the basic knowledge to predict the future distribution and impact of the quagga mussel in Switzerland.

We will use the zebra mussel D. polymorpha as a model species to predict quagga invasion. The zebra mussel is a close relative of the quagga mussel and has invaded Switzerland several decades ago. By investigating its distribution, genetic structure and life history traits we can reveal potential distribution vectors, barriers and limiting factors for the population establishment and growth of the quagga mussel. We will compare the niche constraints of quagga and zebra mussels directly in experiments using mesocosms. Such data should allow to predict the future quagga mussel distribution. Our additional aim is to develop molecular tools for early detection of the quagga larvae in the water column, which is essential for providing an early warning system for authorities. Altogether the data will help to define monitoring and prevention strategies against the spread of the quagga mussel. With this case study we hope not only to derive guidelines for management of aquatic invasive species in Switzerland, but also to gain experience from the interaction with the key stakeholders who will need to take measures due to problems caused by aquatic invasive species.

Disciplines: invasion biology, population genetics, freshwater Ecology

Keywords: invasive species, Dreissena, distribution, spread, source-sink, life history traits

Contact person: Lukas De Ventura, Kirstin Kopp