Future kelp forest communities of Greenland: As part of the FACE-IT project, Nora and Sarina conducted a field work campaign in Nuuk, Greenland in June / July 2023 to answer the question, how future Arctic kelp forest communities might look like. Therefore, they run a multi-factorial experiment in cooperation with Thomas Juul-Pedersen and Tobias Vonnahme from the Greenland Institute for Natural Resources (Pinngortitaleriffik), testing not only the influence of increased temperature but also altered light conditions on two kelp species. They compared eco-physiological and biochemical responses of the Arctic species Agarum clathratum and the cold-temperate species Saccharina latissima.
In summer 2022, Simon and Nora traveled to the Holmfjord Research Station (run by the Norwegian Institute of Marine Research Havforskningsinstituttet) on the east coast of the Porsangerfjord, one of Norway's northernmost fjords. As part of the EU Horizon 2020 project FACE-IT, we collected different kelp species to compare the biochemical and genomic profiles of kelps from different Arctic sites. In addition, we focused on the diversity of fauna found there with the aim of setting up a "barcode library" of the study site for future projects and dove more into zoology with a sea urchin grazing experiment in collaboration with Marie Koch from AWI. Back in Germany, fresh material from Laminaria hyperborea and L. digitata were used in a multi-factorial experiment to investigate the effects of climate change on its dispersal potential in the Arctic.
“Sustainable approaches of aquaculture, such as co-culture and the husbandry of organisms low in the food web, have a long tradition in Asia and the direct consumption of algae is a regular part of the people´s diet.”
In cooperation with the “SeaGrapes” project of the Leibniz Centre for Tropical Marine Research , ZMT (https://www.leibniz-zmt.de/en/research/research-projects/seagrapes.html), a three-month research stay was conducted in Nha Trang, Vietnam. The aim of several field- and laboratory studies was to explore possible co-cultivation approaches of the edible green alga Caulerpa lentillifera, also known as sea grapes or “green caviar”, together with other low-trophic marine organisms like high value red algae (Kappaphycus alvarezii) and fed aquaculture species (the edible marine snail Babylonia areolata).
This summer the first Heligoland expedition of the project sea4soCiety (https://sea4society.cdrmare.de/en/) took place. Within this project, which is part of the research mission CDRmare (https://cdrmare.de/en/), we investigate options for the afforestation of kelp forests in the German Bight. During the first cruise with the research vessel Littorina we took radiation measurements at several locations of kelp forests around the island. Furthermore, we collected fresh samples of the kelp Laminaria hyperborea to determine their photosynthetic activity and light demands. These data will help us to better understand the local conditions of kelp forests around Heligoland and the required conditions for potential afforestation sites. A short documentary about the sea4soCiety expedition to Heligoland can be seen in the NDR mediathek (https://www.ndr.de/nachrichten/schleswig-holstein/salty-FiSH-Kelpwaelder-vor-Helgoland,saltyfish104.html). We further obtained fertile L. hyperborea samples in January which we cultivated in our lab in Bremen. After a few weeks, the first sporophytes were visible, and we continue to cultivate these for future experiments.
We are back to Svalbard! After the pandemic-related break we returned to Kongsfjorden. In the frame of the EU H2020 project FACE-IT we study the impact of terrestrial sedimental run-off on underwater light climate, light availablity and, consequently, photosynthesis, productivity and vertical distribution of seaweeds. We will also collect kelp samples for comparative analyses of biochemical and genomic profiles across the various FACE-IT study sites. Furthermore, we contribute to surveys of the seaweed-associated fauna.
We are back at Kongsfjorden. In the current summer campaign we will focus on the interactive effects of radiation, temperature, salinity and nutrient concentration on seaweed ecophysiology. For Nora Diehl the studies at Kongsfjorden represent the northernmost station of her large-scale project on the impact of heatwaves on the kelp Saccharina latissima along its latitudinal range of distribution. On Svalbard, Johanna Marambio conducts those experiments on temperature and light interaction on the brown seaweed Desmarestia aculeata and the red Palmaria palmata, which she is going to repeat in Antarctica in December 2020. The comparison of related species from regions with different climate history will allow for insights into the evolutionary base of physiologial adaptation strategies.