HE570 expedition, RV Heincke, 2-19 March 2021
The past year has been challenging for everyone, but especially so for marine scientists trying to plan sea-going expeditions. iAtlantic has handled its fair share of rescheduling, replanning and adjusting expectations to adapt to the ever-changing circumstances that the COVID-19 pandemic has brought. However, in spite of some disappointments, opportunities have arisen to get some really exciting science done at sea. One such opportunity is currently underway on the Norwegian coast, where the German research vessel R/V Heincke is undertaking a process study of the biological carbon pump. The original expedition using the submersible JAGO to investigate the booming population of jellyfish in Lurefjord, on the Norwegian coast north of Bergen, was unfortunately cancelled due to the pandemic, but jumping on an opportunity to use RV Heincke means that a team of German scientists is still able to collect measurements that will contribute to iAtlantic’s work on understanding how marine ecosystems respond to environmental change.
The expedition, known as HE570 and led by scientists Klas Möller & Helena Hauss, will conduct a process study of the biological carbon pump (the cycling of carbon through the natural ecosystem) in two Norwegian Fjords that are located close together and are of similar size and structure, but have fundamentally different pelagic ecosystem structures. This makes them ideal environments to use as natural laboratories. One fjord – Masfjorden – sustains populations of mesopelagic fishes (those that live in the middle of the water column, about 200-1000 m water depth) and has negligible populations of jellyfish; the other fjord – Lurefjorden – is characterised by a year-round mass abundance of the deep-sea jellyfish Periphylla periphylla.
The scientists aim to quantify the respective contributions that the different components of the ecosystem (zooplankton and fishes) make to the mass flux of carbon in the natural system. To do this, they will deploy a suite of different state-of-the-art in situ imaging systems, hydroacoustic instruments, sediment traps, and vertically stratified nets. They will also try to collect specimens of the Periphylla jellyfish to measure their response to different temperatures and amounts of sediment in the water, as part of iAtlantic’s work on understanding the effects of multiple stressors on deep-sea ecosystems.