CHRYSOWEB · The effect of mixotrophic chrysophytes on secondary productivity in pelagic food webs
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-02-01 → 2018-01-31
- EU contribution
- €178,157
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
The effect of mixotrophic chrysophytes on secondary productivity in pelagic food webs
Plankton occupy a key position in aquatic trophic webs, therefore, understanding its global change-mediated shifts is of high importance. While changes in the plankton of eutrophic lakes (e.g. increased dominance of cyanobacteria) are a widely discussed topic in the current literature, the consequences of global change for oligotrophic lakes receives little attention. Mixotrophic chrysophytes (golden algae – Chrysophyceae) are important elements of the phytoplankton in lakes with a low nutrient content, such as alpine lakes. Their contribution is predicted to increase with global change-associated phenomena, such as enhanced thermal stratification and increased input of terrestrial carbon (‘brownification’). Though interactions between chrysophytes and zooplankton have hitherto received little attention, some studies clearly indicated detrimental dietary effects. According to this, an increase in chrysophytes could impair secondary production with far-reaching consequences for the whole ecosystem, including changes in the fish stock. Alpine lakes represent multiple ecosystem services. Salmonid fish populations of many mountain lakes are economically important. If golden algae impair zooplankton composition and production, their increase may imply changes in the fish stock. Besides, chrysophyte blooms can cause unpleasant fishy odour, decreasing the recreational value of their habitats. The aim of CHRYSOWEB was to specifically address the consequences of the increasing share of golden algae for consumers in lake food webs. To this end, we applied an integrative approach (laboratory experiments, field observations, biochemical analyses) to get a comprehensive understanding of this key group on aquatic ecosystem functioning. By using an array of chrysophyte species as food, we found multiple effects on zooplankton, which were generally negative compared to a high-quality reference food. The mechanisms include feeding inhibition, nutritional deficiency and toxicity. The results of CHRYSOWEB imply that the dominance of chrysophytes is able to significantly alter zooplankton secondary production and community composition, and therefore energy flow in aquatic food webs.
Data: CORDIS, © European Union
Project objective
Plankton occupy a key position in aquatic trophic webs, and today, a highly relevant topic lies ahead in assessing its global change-mediated shifts, with implications for the functioning of aquatic systems. Mixotrophic chrysophytes are prevailing elements of phytoplankton in oligo- and mesotrophic lakes. Their contribution is predicted to increase with climate warming, which imply serious consequences for pelagic trophic efficiency and ecosystem services e.g. fish production. However, our current knowledge on the nutritional quality and bottom-up effect of chrysophytes is insufficient. CHRYSOWEB aims to reveal their effects on zooplankton secondary production and diversity in a multi-disciplinary approach, which will significantly contribute to the understanding of carbon flow and nutrient cycling in alpine lakes under global change. Laboratory feeding experiments will be combined with field observations to quantify species-specific responses of relevant zooplankton taxa to chrysophytes. The underlying mechanisms will be biochemically analysed in algae and consumers. The host, WasserCluster Lunz (WCL) is a leading limnological institute in Central Europe with cutting-edge infrastructure and outstanding research performance. My supervisor, Dr Robert Ptacnik (leader of AquaScale working group, WCL) has excellent background in plankton ecology and experimental systems. The biochemical part will be performed in cooperation with Dr Martin Kainz (leader of LIPTOX working group, WCL). I will additionally benefit from the international cooperation with Prof Herwig Stibor (LMU Munich; place of secondment). CHRYSOWEB will produce front-line and timely inter-disciplinary results and enhance my future perspectives to become an independent researcher by broadening my expertise both conceptually and methodologically. The inspiring working environment, high-quality infrastructure, excellent supervision and my personal motivation guarantee the successful outcome of the project.
Original text from CORDIS.
Participants
- WASSERKLUSTER LUNZ BIOLOGISCHE STATION GMBH · LUNZ AM SEECoordinatorAustria
Links
Data: CORDIS, © European Union