Food-web ecology is an important pillar in current marine research as it provides a quantitative framework to combine the approaches of community and ecosystem ecology. Food-web ecology is not merely the study of the flow of energy, it also integrates the structure and dynamics of species' feeding relationships in relation to their abundances. Therefore, there is considerable potential to use food webs as a tool for a better understanding of the link between biodiversity and ecosystem functioning. One of the most crucial interactions in marine food webs is realized by primary consumers as they are positioned between lower trophic levels and top predators. This interface between primary producers and their consumers at the basis of marine food webs is of particular interest because of the highly variable efficiency of transfer of biomass and energy, yet governing the rest of the food web.
This research project aims to study the efficeincy of this energy transfer in marine sediments. It will focus on meiofauna (copepods, nematodes) as primary consumers and their main food sources (bacteria, diatoms). Trophic interactions will be traced by means of fatty acids as biomarkers. The transfer of fatty acids from primary producers to their consumers will be studied in relation to (1) food availability and quality, (2) environmental conditions (temperature, nutrient levels, tidal regime) and (3) stressors induced by human activities (anoxia, toxicants, pollution). In order to test these effects, lab experiments will be combined with field data from a wide array of marine habitats.