Life in Lake Constance –
the past, present and future

Lake Constance is one of the largest Alpine lakes, on the border between Germany, Austria and Switzerland – an important drinking water reservoir and ecosystem, significant for tourism, recreation, fishing, nature conservation and energy production.

In the past century, Lake Constance has undergone extensive changes: untreated sewage and intensive agriculture led to severe lake pollution in the 1950-1980s, and Lake Constance became nutrient-rich (eutrophication). Although the natural trophic state has been almost completely restored thanks to countermeasures that were taken, there are irreversible changes to the communities of aquatic organisms. One species of whitefish (Coregonus gutturosus, the Lake Constance whitefish) went extinct during the eutrophication phase, and climate change and the invasion of non-native plant and animal species are potentially endangering natural biodiversity. This can lead to changes in the food webs and affect ecosystem functioning in Lake Constance. Catch yields of fisheries are declining and concerns are being raised regarding increased maintenance costs for municipal water suppliers due to the spread of non-native mussel species (e.g. Quagga mussel). Today, there are more than 37 non-native species in Lake Constance, e.g. three-spined stickleback (Gasterosteus aculeatus), Zebra mussel (Dreissena polymorpha) and killer shrimp (Dikerogammarus villosus).

The objective of the SeeWandel project is to investigate the significance of nutrient decline, climate change, non-native species and other stress factors for the Lake Constance ecosystem, its biodiversity and functioning, as well as the utilisation of lake resources by people. This helps to evaluate important questions regarding the resilience of the Lake Constance ecosystem and potential changes in ecosystem services. In addition, the insights gained will provide a basis for water management and politicians to make scientifically informed decisions about the future of Lake Constance.

Project term: 1st of June 2016 – 30th of June 2022

Total budget: 5.65 m. Euro

In the past century, Lake Constance has undergone extensive changes: untreated sewage and intensive agriculture led to severe lake pollution in the 1950-1980s, and Lake Constance became nutrient-rich (eutrophication). Although the natural trophic state has been almost completely restored thanks to countermeasures that were taken, there are irreversible changes to the communities of aquatic organisms. One species of whitefish (Coregonus gutturosus, the Lake Constance whitefish) went extinct during the eutrophication phase, and climate change and the invasion of non-native plant and animal species are potentially endangering natural biodiversity. This can lead to changes in the food webs and affect ecosystem functioning in Lake Constance. Catch yields of fisheries are declining and concerns are being raised regarding increased maintenance costs for municipal water suppliers due to the spread of non-native mussel species (e.g. Quagga mussel). Today, there are more than 37 non-native species in Lake Constance, e.g. three-spined stickleback (Gasterosteus aculeatus), Zebra mussel (Dreissena polymorpha) and killer shrimp (Dikerogammarus villosus).

The objective of the SeeWandel project is to investigate the significance of nutrient decline, climate change, non-native species and other stress factors for the Lake Constance ecosystem, its biodiversity and functioning, as well as the utilisation of lake resources by people. This helps to evaluate important questions regarding the resilience of the Lake Constance ecosystem and potential changes in ecosystem services. In addition, the insights gained will provide a basis for water management and politicians to make scientifically informed decisions about the future of Lake Constance.

Project term: 1st of June 2016 – 30th of June 2022

Total budget: 5.65 m. Euro

13 projects from 7 institutes

SeeWandel comprises 13 sub-projects whose investigations contribute to an improved process-based understanding of the pelagic zone (off shore open water area) and littoral zone (shore area), as well as interactions between them.

Pelagic zone

Sub-projects

P1: The stickleback in Lake Constance-Obersee

PD Dr. Alexander Brinker, Sarah Gugele
Fisheries Research Centre Langenargen (Fischereiforschungsstelle, FFS) of the Agricultural Centre for Cattle Farming, Grassland Management, Dairy Farming, Game and Fisheries Baden-Württemberg (LAZBW), Germany

In cooperation with
PD Dr. Jasminca Behrmann-Godel
University of Konstanz, Dept. of Biology – Limnological Institute, Germany
Prof. Dr. Helge Balk
University of Oslo, Department of Physics, Norway

The ultimate goal of this project is to examine to what extent, and using which measures, the abundance of the non-native three-spined stickleback can be reduced. Acoustic surveys with parallel trawl nets and ecological studies are carried out with the aim of distinguishing sticklebacks from whitefish in the lake. A reduction in the stickleback population, and concomitant reduction of its impact on food competition and recruitment, could lead to recovery of whitefish populations and populations of other affected native fish species (e.g. perch) within the scope of available primary production.

Projectdetails to download

P2: Bioenergetic modelling of fishing strategies on the fish communities of Lake Constance-Obersee

PD Dr. Alexander Brinker
Fisheries Research Centre Langenargen (Fischereiforschungsstelle, FFS) of the Agricultural Centre for Cattle Farming, Grassland Management, Dairy Farming, Game and Fisheries Baden-Württemberg (LAZBW), Germany

This project deals with the problem of declining whitefish catches and the planned scaling-back of professional fisheries. Based on certain theories (e.g. fishing strategies adapted to recruitment, density-dependent growth) and on the basis of specific models, different scenarios are simulated and their effects estimated, with the aim of identifying new approaches to management that can help both professional fisheries and whitefish.

P3: Effects of re-oligotrophication, climate change and fisheries-management on fish-zooplankton interactions and the population dynamics of whitefish

PD Dr. Dietmar Straile, Žiga Ogorelec
University of Konstanz, Dept. of Biology – Limnological Institute, Germany
Research Training Group “R3 – Responses to biotic and abiotic Changes, Resilience and Reversibility of Lake Ecosystems”
PD Dr. Alexander Brinker
Fisheries Research Centre Langenargen (Fischereiforschungsstelle, FFS) of the Agricultural Centre for Cattle Farming, Grassland Management, Dairy Farming, Game and Fisheries Baden-Württemberg (LAZBW), Germany

In cooperation with
PD Dr. Jasminca Behrmann-Godel
University of Konstanz, Dept. of Biology – Limnological Institute, Germany
Prof. Dr. Lars Gosta Rudstam
Cornell University, College of Agriculture and Life Sciences, Dept. of Natural Resources, USA

This project, based on long-term data, provides an important basis for estimating the resilience of the zooplankton community and the whitefish population of Lake Constance. An improved understanding of fish-zooplankton interactions will contribute to the development of a whitefish population dynamics model. The model uses simulations to investigate the influence of changes in trophic and climatic conditions, as well as fisheries measures (e.g. mesh sizes, larval stocking by fish hatcheries), on whitefish population development, and thus also to predict the effect of these variables on the yield of commercial fisheries in the oligotrophic Lake Constance.

Projectdetails to download

P4: Reconstruction of the genome of the extinct Lake Constance whitefish and characterisation of the genetic bases of habitat adaptation to the profundal zone

Dr. Philine Feulner, Prof. Dr. Ole Seehausen, David Frei
Eawag, Fish Ecology and Evolution, Kastanienbaum, Switzerland
University of Bern, Dept. of Biology, Institute of Ecology and Evolution, Switzerland

The aim of the project is to characterise the genome of the extinct whitefish and other Lake Constance whitefish to investigate what prevents whitefish from re-colonising their original habitat, the profundal zone (deep zone) in Lake Constance. The insights gained into the origin and loss of biodiversity of endemic fish in the deep lakes surrounding the Alps, as well as a better understanding of the genetic basis of species diversity, ecological species differences and the genetics of adaptation, provide new insights into the adaptive potential of the remaining whitefish in Lake Constance and the restoration of their original biodiversity.

P5: Daphnia resilience - comparison of genomic and functional resilience of the water flea population under eutrophication and oligotrophication in Lake Constance, Lake Zurich and Lake Walen

Dr. Markus Möst
University of Innsbruck, Institute of Ecology Research, Austria

This project quantifies the extent of gene flow between the invasive aquatic flea species Daphnia galeata and the native species Daphnia longispina, which was facilitated by lake eutrophication. It also investigates the effects of this process on the fitness of the water flea population, the function of these key species in the ecosystem, their evolutionary and adaptive potential and the reversibility of the hybridization process. By comparing three lakes, conclusions can be generalized and the processes in Lake Constance put in context, which will allow a better assessment of the impact of human activities and the targeted planning of an appropriate water management programme.

P6: Reasons for the growth of Planktothrix rubescens in Lake Zurich and Lake Constance – comparison of long-term data, experimental approaches and genetic analyses

Prof. Dr. Thomas Posch, Prof. Dr. Jakob Pernthaler, Deborah Knapp, Dipl. Ing. Eugen Loher
University of Zurich, Limnological Station Kilchberg, Switzerland

This project investigates the resilience of the Lake Constance ecosystem to the mass appearance of the toxic burgundy blood algae (Planktothrix rubescens) and the extent to which it affects the lake’s core ecosystem functions (e.g. food web structure, nutrient availability). Long-term data from Lake Zurich serve as the basis for the development of forecasts regarding the further development of this alga in Lake Constance. A brochure about the mass appearance of the burgundy blood algae is being prepared for a wider public. 

P7: Distribution of planktic communities in Lake Constance-Obersee

Dr. Frauke Lüddeke, Dr. Harald Hetzenauer, Dr. Bernd Wahl, Dr. Thomas Wolf
Institute for Lake Research (Institut für Seenforschung, ISF) of the State Agency for Environment Baden-Württemberg (LUBW), Germany

The goal of this project is to develop new methods to continuously measure the patchiness and seasonal dynamics of zooplankton and phytoplankton in Lake Constance-Obersee. For that, sonde (e.g. Fluoroprobe) and hydroacoustics data will be compared to traditional collected data. The results will serve as a basis for the establishment of modern measuring methods and the optimisation of joint monitoring among the states bordering Lake Constance, which is essential for the protection and conservation of biodiversity. (Picture LUBW)

P8: Resilience of Lake Constance from a paleolimnological point of view

PD Dr. Dietmar Straile
University of Konstanz, Dept. of Biology – Limnological Institute, Germany

In this project, paleolimnological data are used to analyse whether the current status of the plankton community (achieved through lake re-oligotrophication) has returned to that of the 1950s (i.e. years of similar total phosphorus levels). The trophic state is reconstructed on the basis of the diatoms or Clacodera (water fleas) in the different lakes (Lake Constance, Lake Walen, Lake Zurich) or lake parts of Lake Constance, with the aim of investigating the resilience and reversibility of the plankton community.

Projectdetails to download

Littoral zone

Sub-projects

L9: Resilience of the littoral community of Lake Constance: effects of neozoa, trophic- and climate change

Prof. Dr. Karl-Otto Rothhaupt, PD Dr. Dietmar Straile, Maike Sabel
University of Konstanz, Dept. of Biology – Limnological Institute, Germany
Research Training Group “R3 – Responses to biotic and abiotic Changes, Resilience and Reversibility of Lake Ecosystems”
Sampling performed by Hydra Constance, Germany

This project examines the effects of environmental changes (re-oligotrophication, climate change, immigration of non-native species) on the structure (e.g. relative species composition, species and functional diversity, changes in traits) and resilience of littoral food webs. Long-term data allow the detailed study of the colonisation dynamics of neozoa and their influence on littoral communities. The project will also collect quantitative data related to the invasion of the Quagga mussel, to evaluate its significance for the Lake Constance ecosystem.

Projectdetails to download

L10: Competition between filter feeders in Lake Constance

PD Dr. Piet Spaak , Dr. Stuart Dennis, Linda Haltiner
Eawag, Aquatic Ecology, Dübendorf, Switzerland

In cooperation with
Prof. Dr. Karl-Otto Rothhaupt
University of Konstanz, Dept. of Biology – Limnological Institute, Germany
Hydra Constance, Germany

The aim of this project is to investigate the effects of invasive mussels (Quagga mussel Dreissena rostriformis bugensis, Zebra mussel D. polyformus) on the Lake Constance food web (e.g. food availability for fish). It will also quantitatively assess the impact of invasive mussels on measures developed to counteract economic losses (e.g. decrease of fisheries yields) and to develop an effective management strategy for Lake Constance. For this, a better understanding of the competitive relationships between the filter feeders in Lake Constance is essential.

Projectdetails to download

L11: Resilience of submerged macrophytes in the littoral zone of Lake Constance

Prof. Dr. Klaus Schmieder, Dipl.-LaÖk. Gunnar Franke
University of Hohenheim, Institute of Landscape and Plant Ecology, Germany

In cooperation with
Dr. Peter Gege
German Aerospace Center (DLR), Remote Sensing Technology Institute, Germany
Holger Bischoping
BGC – Bischoping Geoinformation Consulting, Germany

In this project, the current macrophyte stocks are assessed at species level and compared with previous aerial mapping of species composition and vegetation structure. The data collected and the developed bioindicative assessment modules form the basis for the development of interpretable and planning-relevant multitemporal information (GIS) on the ecological status of the littoral zone. Visualised remote sensing products will enable rapid, high-quality planning, monitoring and reporting by public authorities and the water industry, as well as sustainable biodiversity management.

(right picture by M. Mörtl)

 

 

 

L12: Development and application of methods for the assessment of fish communities in large and deep lakes

PD Dr. Alexander Brinker, Barbara Scholz
Fisheries Research Centre Langenargen (Fischereiforschungsstelle, FFS) of the Agricultural Centre for Cattle Farming, Grassland Management, Dairy Farming, Game and Fisheries Baden-Württemberg (LAZBW), Germany

This project aims to develop an effective, standardised, financially and logistically sustainable fishing strategy for Lake Constance (building on the 2014 assessment), which supports future monitoring of fish communities, minimises fish mortality and takes account of the horizontal and vertical distribution of fish throughout Lake Constance. The knowledge gained, also with regard to population dynamics and correlations, contributes to the development of a sustainable biodiversity management in Lake Constance.

Projectdetails to download

L13: Ecology and diversity of stickleback in Lake Constance

Dr. Blake Matthews, PD Dr. Piet Spaak, Prof. Dr. Ole Seehausen
Eawag, Aquatic Ecology, and Fish Ecology and Evolution, Switzerland
University of Bern, Dept. of Biology, Institute of Ecology and Evolution, Switzerland

The aim of this project is to understand what ecological and evolutionary processes might explain the abundance, distribution, and phenotype of stickleback in Lake Constance. This will provide important insights into the management of the Lake Constance ecosystem and the assessment of population control measures of the sticklebacks.

Complementary:

Chemical and biological monitoring performed by IGKB.

Project management

Swiss Federal Institute of Aquatic Science and Technology (Eawag)

Ueberlandstrasse 133
8600 Duebendorf
Switzerland

Email: seewandel@seewandel.org


Project leader

PD Dr. Piet Spaak
Aquatic Ecology

Phone: +41 (0)58 765 5617
Email: seewandel@seewandel.org


Project coordination

Dr. Josephine Alexander

Phone: +41 (0)58 765 6885
Email: seewandel@seewandel.org


Project administration

Arianne Maniglia

Phone: +41 (0)58 765 5132
Email: seewandel@seewandel.org


Partners

Agricultural Centre for Cattle Farming, Grassland Management, Dairy Farming, Game and Fisheries Baden-Württemberg (Landwirtschaftliches Zentrum für Rinderhaltung, Grünlandwirtschaft, Milchwirtschaft, Wild und Fischerei Baden-Württemberg, LAZBW)

Fisheries Research Centre Baden-Württemberg (Fischereiforschungsstelle Baden-Württemberg, FFS)


State Agency for Environment Baden-Württemberg (Landesanstalt für Umwelt
Baden-Württemberg, LUBW)

Institute for Lake Research (Institut für Seenforschung, LUBW-ISF)

www.lubw.baden-wuerttemberg.de/wasser/institut-fuer-seenforschung


University of Hohenheim


University of Innsbruck


University of Konstanz


University of Zurich


Supporters

Interreg Alpenrhein-Bodensee-Hochrhein


Canton of Zurich, Building Department, Office of Waste, Water, Energy and Air (WWEA)


Federal Office for the Environment (FOEN)


Free State of Bavaria


Lake Constance Water Industries Association (Zweckverband Bodensee-Wasserversorgung)


International Commission of Lake Constance Water Conservation
(Internationale Gewässerschutzkommission für den Bodensee, IGKB)


International Delegate Conference of Lake Constance Fisheries
(Internationale Bevollmächtigtenkonferenz für die Bodenseefischerei, IBKF)