Who eats whom and when? Zooming-in on alternative energy transfer pathways in planktonic food webs of hypertrophic shallow lakes

Principal investigator: Dagmara Sirová
(Co)investigator from the Department: Jaroslav Vrba
Funding provider: The Czech Science Foundation
Duration: 2019 to 2021

Project goals: 
To unravel complex interactions in planktonic food webs of the underexplored but important aquatic ecosystems at an unprecedented level of resolution, using a unique combination of molecular, epifluorescence, and chemical methods.

Project description: 
Freshwater planktonic food webs (FW) are crucial for understanding of energy and material flow among organisms in the water column. Though theory on FW structure and function is advancing rapidly, it remains poorly resolved and based on relatively simple systems in stratified lakes. Shallow polymictic ecosystems such as hypertrophic fishponds, however, seem to support more complex communities of immense biodiversity. Based on our preliminary results, we hypothesise that, contrary to the widely accepted plankton ecology paradigms, methane-oxidising bacteria, picocyanobacteria, and fungal zoospores are important players in the transfer of energy to higher trophic levels in hypertrophic lakes. The flow of energy from primary producers to higher trophic levels through the ‘classical FW’ is reduced here, the microbial FW is the main component, although likely less efficient due to more trophic levels and consequent energy losses. To unravel these complex interactions at a sufficient level of resolution, a combination of modern molecular methods and multidisciplinary skills is planned.