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The impact of abiotic factors on hybrid Daphnia populations across the Alps: are pollution effects irreversible?

Applicant Spaak Pieter
Number 125211
Funding scheme Interdisciplinary projects
Research institution Swiss Federal Institute of Aquatic Science and Technology (EAWAG)
Institution of higher education Swiss Federal Institute of Aquatic Science and Technology - EAWAG
Main discipline Ecology
Start/End 01.10.2009 - 30.09.2012
Approved amount 332'664.00
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All Disciplines (4)

Discipline
Ecology
Other disciplines of Environmental Sciences
Hydrology, Limnology, Glaciology
Geology

Keywords (11)

hybridization; climate change; zooplankton; lakes; sediment; pollution; population genetics; resurrection ecology; evolution; toxic compounds; biodiversity

Lay Summary (English)

Lead
Lay summary
The reconstruction of the effects of environmental changes to Biodiversity is mostly difficult because long time series are failing. We use DNA from diapausing stages of small crustaceans, buried in the lake sediment, to study these effects.The effect of rapid ecological change in ecosystems has been the topic in many studies of recent years. Only a limited number has concentrated on the impact of invading and hybridizing taxa and even less were able to determine the ecological and evolutionary processes occurring in these scenarios. It is a fact that anthropogenic alterations of habitats have facilitated successful invasions of species. Furthermore, interspecific hybridization between the invader and the indigenous species has led to irreversible changes in the genetic composition of present populations. Today, many freshwater bodies have recovered from antropogenically induced eutrophication 30 - 50 years ago. Nevertheless, toxic compounds are still present, together with climate change they are future threats that natural populations of planktonic organisms encounter. In our work on Daphnia (water flea) we observed that interspecific hybridization occurs frequently in lakes North and South of the Alps and best explained by the eutrophication history of these. We hypothesize that D. galeata is native to lakes South of the Alps and D. hyalina in the North. We expect to find this pattern in diapause archives of selected lakes. We will analyse the past population structure using high resolution molecular markers. We want to test whether other influences than eutrophication like toxic compounds facilitated the dispersal of both species across their original borders, and how it affects the succession of taxa within a lake. This research will provide new insights on the impact of toxic compounds, global change and their interaction on hybridizing (invasive) species and their potential effect on Biodiversity. Our research will show the role of environmental variation in these interactions, and provide a novel insight in the genetic patterns of adaptive traits to temperature and chemical stressors.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
At the edge and on the top: molecular identification and ecology of Daphnia dentifera and D. longispina in high-altitude Asian lakes
Möst Markus, Petrusek Adam, Sommaruga Ruben, Juracan Petr Jan, Slusarczyk Miroslav, Manca Marina, Spaak Piet, At the edge and on the top: molecular identification and ecology of Daphnia dentifera and D. longispina in high-altitude Asian lakes, in Hydrobiologia.

Collaboration

Group / person Country
Types of collaboration
CNR/ISE Verbania Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Institute for Lake Research, Langenargen Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
University of Mailand Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
University of Konstanz Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
German Zoological Society 105th Annual Meeting 21.09.2012 Konstance, Germany
Second ECO-PhD Symposium 22.05.2012 Dübendorf, Switzreland
6th SETAC World Congress 20.05.2012 Berlin, Germany
5th IBP PhD congress 13.04.2012 Zürich, Switzerland
Ninth International Symposium on Cladocera, Verbania 02.10.2011 Verbania, Italy
Fifth International Limnogeological Congress (ILIC), Constance (Germany) 09.09.2011 Konstanz, Germany
13th EuCheMS International Conference on Chemistry and the Environment (ICCE) Zurich (Switzerland) 01.09.2011 Zurich (Switzerland)
Platform presentation at the conference „Emerging Contaminants in the Environment“ (EmCon 2011), Copenhagen, Denmark 08.08.2011 Copenhagen, Denmark
First ECO-PhD Symposium, Dübendorf (Switzerland), 09.05.2011 Dübendorf, Switzerland
4th congress of the Institute of Biogeochemistry and Pollutant Dynamics (IBP), Zurich (Switzerland) 01.04.2011 Zürich, Switzerland
Sixth International Symposium on Eco-Evolutionary Dynamics, Leuven (Belgium) 09.02.2011 Leuven


Associated projects

Number Title Start Funding scheme
116470 Host-parasite interactions in hybridizing Daphnia, the role of variable environments 01.08.2007 Project funding
142165 The impact of cyanobacterial blooms triggered by nutrient pollution on aquatic environments in the context of climate change 01.01.2013 Romanian-Swiss Research Programme
140996 The impact of abiotic factors on hybrid Daphnia populations across the Alps: are pollution effects irreversible? (4th year prolongation) 01.10.2012 Interdisciplinary projects
135750 Host - parasite interactions in hybridizing Daphnia, the role of variable environments: part 2. 01.01.2012 Project funding
65003 Biotic interactions and the maintenance of a Daphnia hybrid species complex 01.04.2002 Project funding

Abstract

Background - The effect of rapid ecological change in ecosystems has been the topic in many studies of recent years. Only a limited number have concentrated on the impact of invading and hybridizing taxa and even fewer were able to determine the ecological and evolutionary processes occurring in these scenarios. It is a fact that anthropogenic alterations of habitats have facilitated successful invasions of species. Furthermore, interspecific hybridization between the invader and the indigenous species has led to irreversible changes in the genetic composition of present populations.Today, many freshwater bodies have recovered from anthropogenically induced eutrophication 30 - 50 years ago. Nevertheless, toxic compounds are still present, and together with climate change they are future threats that natural populations of planktonic organisms encounter. The Arrhenius equation states that an increase in temperature by 10°C will double to quadruple the rate of a chemical reaction. This also applies for the toxicity of compounds on Daphnia (water flea), one of the most dominant zooplanktonic algal grazers in freshwater systems. In our work on Daphnia we observed that interspecific hybridization occurs frequently. Hybridization and introgression were detected in a wide range of lakes north and south of the Alps and best explained by the eutrophication history of these lakes. Furthermore, we found that lakes south of the Alps are dominated by D. galeata and north of the Alps by D. hyalina, moreover lakes in the north were invaded by D. galeata during eutrophication. In addition, we were able to show that Daphnia species have adapted to different temperature regimes and that this characteristic is related to their mitochondrial origin. Working Hypothesis - We hypothesize that D. galeata is native to lakes south of the Alps and D. hyalina in the north. We expect to find this pattern in diapause archives of selected lakes. We will analyse the past population structure using high resolution molecular markers and advanced analysis software. We want to test whether influences other than eutrophication, like toxic compounds, facilitated the dispersal of both species across their original borders, and how they affect the succession of taxa within a lake. In order to find the relevant toxins we will analyse sediments for ~200 defined compounds from which some key components will be chosen for further studies. Since dispersal patterns differ on both sides of the Alps, we hypothesize that Daphnia species distribution is correlated with temperature and aim to test the reaction of daphnids to the selected toxic chemicals like pesticides, pharmaceuticals and heavy metals against temperature. Therefore, we will test Daphnia in life history experiments and EC50 dose response curves. Our aim is to better understand the impact of present and future stressors and, furthermore, understand how they interact with interspecific hybridization and introgression. For this purpose we will develop microarrays based on EST databases for D. galeata and conduct life history experiments, processing the obtained RNA isolates in gene expression analyses.Experimental Design and / or Methods - The proposed research plan blends several disciplines: Evolutionary Biology and Ecotoxicology/Ecochemistry, which are to be studied from a “Paleo-perspective”. We are confident that with this approach we can reconstruct habitat perturbation over the last century and establish models that can be used to determine the reactions of Daphnia, a model for Holarctic freshwater organisms, to future changes in their abiotic environment. We propose to divide the work among two researchers, a Post Doc who will be responsible for the evolutionary part of the project as well as part of the ecotoxicology, and a PhD student who will be responsible for the chemistry part as well as ecotoxicological experiments with Daphnia. The work is divided in three work packages: A: Sediment & Population Genetics; B: Sediment & Chemistry and C: Ecotoxicology. Part A and B will start simultaneously, whereas in the second part of the project work package C will be conducted as a common effort.Expected Value of the Proposed Project - This research will provide new insights on the impact of toxic compounds, global change and their interaction on hybridizing (invasive) species and their potential effect on biodiversity. Our research will show the role of environmental variation in these interactions, and provide novel insights into the genetic patterns of adaptive traits to temperature and chemical stressors.
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