The first major activity of the project was my secondment at SAMS in Scotland in March 2019. Here I experimentally created flocculation of DOM and tested whether pelagic protist could feed on the flocs by measuring their net growth. The expertise of my host Professor Mike Zubkov helped be gain important insights on the subject, that have been extremely useful to the following research. Also, it was a fantastic opportunity to work with a sorting flow cytometer and the protists cultures available at the host institution.
The second major activity was establishing a method for quantifying flocculation of DOM. The protocol was established together with Dr. Rachel Sipler, who leads a research group at Memorial University and is the Canada Research Chair in Ocean Biogeochemistry. The technique enables separation of newly formed flocculates and following analysis of both the particulate and the dissolved phase. I coordinated and led cross-Arctic efforts to perform these experiments at 10 different sites in the summer of 2019: multiple sites in Arctic Canada (by Dr. Rachel Sipler), Svalbard (by Dr. Oliver Müller), Western Greenland (Dr. Friederike Gründger), Eastern Greenland (Maria Lund Paulsen) and Arctic Russia (Maria Lund Paulsen).
The third major activity took place in August 2019 when I participated in a very successful field campaign to NE Greenland Young Sound. There I collaborated closely with 4 other young scientists our common aim was to determine the fate of allochthonous material and organic matter (OM) coming from glacial melt water and rivers in Young Sound and its effects on biological communities.
Our specific objectives were:
1. Quantity and quality (bioavailability) of OM and allochthonous matter coming from freshwater sources (Tyroler and Zackenberg river)
2. Quantify the transformation of dissolved to particulate OM (i.e. flocculation) when the freshwater enters the fjord
3. Sediment traps: the sedimentation of autochthonous vs. allochthonous matter along a gradient from the river and its bioavailability
4. Sediment cores: Remineralization and burial of allochthonous material in sediments along a gradient from the river
5. Study the effects of allochthonous material on biological processes (i.e. copepod mortality and bacterial growth/diversity)
The fourth major activity was to complete all laboratory analysis of all samples collected in Greenland and the cross-arctic flocculation experiments. I spend some effort getting experience with the IR-MS (isotopic-ratio mass spec) as this was a new technique for me and I had to run it independently for several months. I learned to use a CytoFlex flow cytometer, on which I ran samples. Further, I developed extensive experience with DNA extraction techniques. I much appreciate expanding my skills in the laboratory.
Now all samples are measured I will spend my remaining time as a MSCA-postdoc on writing papers and outreach activities. Further I am participating in a postdoc training course in Bayesian Statistics.
Dissemination activities of my project has so far included:
1) A scientific talk at Arctic Science Summit Week 2019 in Arkhangelsk.
2) A seminar at the seminar club of The Technical University of Denmark, Section of Aquatic Science.
3) I have published a book chapter: Doi: 10.1002/9781119300762.wsts0199
4) I have published popular science articles:
https://iasc.info/news/iasc-news/502-glacial-runoff-and-coastal-flocculation-of-terrestrial-matter-by-maria-paulsen-2019-marine-working-group-fellow(s’ouvre dans une nouvelle fenêtre)5) I have co-authored a scientific publication on the theme within my WP4:Societal importance of Antarctic negative feedbacks on climate change: blue carbon gains from sea ice, ice shelf and glacier losses.
6) I have supervised 2 PhD students and assisted grad-school studens with assignments on Arctic coastal ecology
