Trophic ecology of Arctic gelatinous zooplankton
Gelatinous zooplankton (GZP), comprising ctenophores, cnidarians, and tunicates, gained more interest in recent years. During favourable conditions, GZP is known to rapidly increase in biomass and several dominant species are able to exploit the zooplankton standing stock. Since GZP biomass may increase with ongoing warming in the Arctic Ocean, similar to elsewhere in the World Ocean, it is likely that GZP range shifts will take place concomitant with the Atlantification of the Arctic. Thus, it is crucial to gain knowledge about their role in the Arctic marine food web. Because of GZP having low nutritional values, they were considered to be a “trophic dead end”, until modern methods like video logging, biomarkers, and molecular diet studies introduced a paradigm shift regarding the role of jellyfish as prey for different fish and seabird species worldwide. In this project, we will use DNA metabarcoding to reveal the role of GZP in the diet of Arctic and sub-Arctic fish species. Additionally, the role of so-called “jellyfalls” as a carbon source for the Arctic deep-sea benthic communities will be investigated by applying DNA metabarcoding on the stomach contents of scavenging benthic amphipods. The role of GZP as predators in the Arctic Ocean during different seasons will also be investigated. To do so, DNA metabarcoding of the gastric pouch of dominant GZP species in the Arctic Ocean will be performed, to detect, amongst others, predation on ichthyoplankton. Additionally, biomarkers will be used to determine the trophic position of GZP in the Arctic marine food web and to reveal the role of the ice-algal pathway in the diet of GZP. The obtained data will reveal which fish species may be competitors of predators on jellyfish and, hence, will contribute to improve food web models of the Arctic marine ecosystem, currently neglecting the role of GZP.
AWI Organizations > Biosciences > Functional Ecology
PS > 126/2