Kongsfjorden long-term seasonal pelagic monitoring program

With the current and constant threat of climatic conditions and, consequently, with the increase of water temperature, and the intensification of the influx of heat from the Atlantic water to the Arctic (a phenomenon known as Atlantification) and the melting of icebergs, analysis and investigation such as these the diversity and function of planktonic microbiomes of the Atlantic Ocean must be done. Understanding the dynamics of the microbial communities that feed Arctic phytoplankton and are essential for the biogeochemical cycles is extremely necessary to understand what is happening on the planet. In this study, we present a temporally extensive analysis of the Kongsfjorden (Svalbard, Norway) marine microbiome diversity and distribution over 5 years (2019, 2020, 2022, 2023, and 2024). From late spring to late summer, during the Norwegian Polar Institute Seasonal Pelagic Monitoring Campaign, samples were collected at two depths (Surface and Bottom) across the fjord. Samples were collected on board with a Niskin bottle, filtered through a 0.22µM Sterivex filter, and preserved at -80ºC for later DNA extraction. Amplification of 16S rRNA and 18S rRNA genes was performed and sequenced on Illumina MiSeq. The prokaryotic and eukaryotic Kongsfjorden data sets collection comprises highly complex and diverse microbial communities with a marked temporal difference. Strong links were observed between the microbes and phytoplankton communities driven by environmental factors, most relevant to unravel the role of microbial pathways in supporting Arctic Ocean primary productivity.