The trophic transfer efficiency at the pelagic phytoplankton‐zooplankton interface is—among other factors—governed by the dietary availability of polyunsaturated fatty acids (PUFAs) to herbivorous zooplankton. As most zooplankton taxa cannot synthesize PUFAs de novo, the phytoplankton PUFA composition is crucial for the herbivores' fitness. As PUFA synthesis is taxon‐specific in phytoplankton, alterations in phytoplankton biod...

Nutrient dynamics in headwater streams are governed by benthic and hyporheic biofilms, with carbon (C) : nitrogen (N) : phosphorus (P) ratios driving the heterotrophic microbial biofilm development through nutrient limitation. Furthermore, heterotrophic responses to changes in C : N : P ratios are probably modulated by autotrophic responses to light and C : N : P ratios, which modify the amount and composition of photosyntheti...

This multi‐year study highlights the ecological role of diversity and fatty acid availability in phytoplankton communities and their complex interactions with zooplankton. These findings, achieved through large‐scale mesocosm experiments, provide novel evidence of the critical role of biochemical components in shaping zooplankton community composition in natural environments, which short‐term and less complex laboratory studie...

A multitude of anthropogenic stressors drive biodiversity loss and alter ecosystem functioning. Freshwaters, which contribute disproportionally to global biodiversity and biogeochemical cycles, are particularly threatened. Although the relationship between biodiversity and ecosystem functions (BEF) is generally well‐established, especially in terrestrial ecosystems, the role of multiple, co‐occurring stressors in modulating th...

Greenhouse gas emissions lead to ocean warming and acidification, negatively impacting marine organisms and their functioning, including long‐chain polyunsaturated fatty acid (LC‐PUFA) production by marine microalgae. Copepods, primary consumers of microalgae, possess a unique capacity for endogenous LC‐PUFA biosynthesis, possibly enabling them to cope with reduced dietary LC‐PUFA availabilities. However, this capacity may be...

This study examined the effects of a moderately intense seven-week running intervention on the hippocampal volume and depressive symptoms of young men (20–31 years of age) from the general population ( N = 21). A within-subjects-design involving a two-week baseline period before the running intervention, and two subsequent intervention cycles was applied. At four time points of assessment (t 1 : start of the study; t 2 : end o...

Spatial and temporal zooplankton feeding dynamics across the water column of lakes are key for understanding site-specific acquisition of diet sources. During this 6-week lake study, we examined stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes and conducted compound-specific fatty acid (FA) stable isotope analysis (CSIA) of edible seston in the epi-, meta-, and hypolimnion, and zooplankton of Lake Lunz, Austria. We predic...

In the light of the current biodiversity crisis that affects in particular freshwater ecosystems, it is crucial to understand the effects of functional diversity loss on phytoplankton-zooplankton interactions in freshwater food webs. Here, we simulated the loss of phytoplankton trait diversity by applying different intensities of mechanical disturbance to a natural phytoplankton community in a laboratory experiment. Different...

The aquaculture production of pikeperch has reached commercial scale in a number of European countries, but the high mortality of early life cycle stages and minor understanding of nutritional requirements are still major bottlenecks. To investigate the fate of fatty acids during early development, weaning and rearing, pikeperch larvae and juveniles from a commercial recirculating aquaculture system (RAS) were sampled over 2 m...

The CORDEX Flagship Pilot Study ELVIC (climate Extremes in the Lake VICtoria basin) was recently established to investigate how extreme weather events will evolve in this region of the world and to provide improved information for the climate impact community. Here we assess the added value of the convection-permitting scale simulations on the representation of moist convective systems over and around Lake Victoria. With this...

Both the quantity and nutritional quality of food resources can strongly influence the foraging movements of herbivores, which in turn determine the strength of top-down control on primary producer biomass. Nutrient enrichment can alter the biomass and nutritional quality of primary producers, but the consequences for the foraging of herbivores and hence for top-down control are still poorly understood. In this study, we combi...

Long‐chain (≥C 20 ) polyunsaturated fatty acids (LC‐PUFAs) are physiologically important fatty acids for most animals, including humans. Although most LC‐PUFA production occurs in aquatic primary producers such as microalgae, recent research indicates the ability of certain groups of (mainly marine) invertebrates for endogenous LC‐PUFA biosynthesis and/or bioconversion from dietary precursors. The genetic pathways for and mech...

Chemical communication via infochemicals plays a pivotal role in ecological interactions, allowing organisms to sense their environment, locate predators, food, habitats, or mates. A growing number of studies suggest that climate change‐associated stressors can modify these chemically mediated interactions, causing info‐disruption that scales up to the ecosystem level. However, our understanding of the underlying mechanisms is...

Communication among marine organisms are generally based on production, transmission, and interpretation of chemical cues. Volatile organic compounds (VOCs) can act as infochemicals, and ocean acidification can alter their production in the source organisms as well as the interpretation of the information they drive to target organisms. Two diatoms ( Cocconeis scutellum var. parva and Diploneis sp.) and a macroalga ( Ulva prol...

Spatial variations in light and nutrient availability usually lead to a heterogeneous distribution of periphyton biomass within streams, but the effects of nutrient enrichment on periphyton heterogeneity are still poorly understood. We tested phosphorus enrichment effects on the heterogeneity of periphyton quantity and nutritional quality in an environment with uneven light conditions. Natural periphyton was grown at either hi...

Essential polyunsaturated fatty acids (PUFAs) have been recognized as a crucial factor that determines the trophic transfer efficiency in plankton communities. As many animals cannot synthesize the classes of ω3‐ and ω6‐PUFAs, the dietary availability of these PUFAs can constrain the fitness of freshwater zooplankton such as Daphnia spp. In particular, eicosapentaenoic acid (EPA, 20:5ω3) is considered to be a crucial determina...