Some of the research topics currently addressed by ARJEL:
How diverse are gelatinous zooplankton communities in the Arctic Ocean?
Since gelatinous zooplankton are fragile and easily fragmented, there are some biases associated with net and trawl sampling. We use integrative field surveys (see also the section “Methods used”) combining nets, optical instruments (imaging or video footage), and environmental DNA (eDNA) studies of water and sediment, to get an accurate estimate of jellyfish diversity, distribution patterns and abundances. During the FramJelly project, a collaboration between AWI and GEOMAR, on PS126 (schematic below), we compared the outcome of jellyfish diversity sampled with depth-stratified nets like the Multinet, eDNA community composition in the water column at different depths, and the results of the annotations of video footage of the Pelagic In Situ Observation System (PELAGIOS, GEOMAR). With these studies in Fram Strait, the Atlantic gateway to the Arctic, we also aim to set a baseline of gelatinous zooplankton diversity for long-term monitoring in this area which acts as a sentinel for future changes further north. In collaboration with GEOMAR, we have samples for eDNA from different years (2019-2021) and aim to continue sampling these same stations on an annual basis.