Diatom valve counts from Young Sound fjord, North-East Greenland

Datasets collected from Young Sound fjord, Northeast Greenland, between 2013 and 2018 were analysed for amounts of diatoms. An automated PPS4/3 sediment trap with an aperture of 0.05 m² was installed near the fjord entrance (74.322°N; 20.269°W) at 60-m water depth, 15 m above the seafloor as part of the Greenland Ecosystem Monitoring (GEM) programme. The rotation for the trap was set to 7 to 91 -day intervals. Diatoms were counted and identified using a Zeiss Axio Imager.A2 upright research microscope with a Plan-Apochromat 100×/1.4 oil immersion objective, phase contrast optics and a total magnification of ×1000. A minimum of 300 valves, excluding Chaetoceros spp. resting spores, which were counted in addition, were identified. For samples with very low diatom abundances, ten transects were counted from each slide.