Fig. 2: Exemplary light microscopy images of marine aggregates from MSC deployments in Fram Strait.

a, b Aggregates dominated by diatoms from ice-covered region -‘EG’, where (a) is mainly diatoms and (b) is diatoms together with Phaeocystis spp. c, d Aggregates dominated by flagellates in the ice-free region - ‘HG’, where (c) is a copepod fecal pellet composed of flagellates and (d) is a marine snow aggregate formed from Phaeocystis spp. colonies. e Chains of Melosira spp., diatoms growing under the sea ice. f Calanus spp. (copepod) fecal pellets collected at the ice-covered region - ‘N’ and formed from mainly Phaeocystis spp. colonies with a few diatoms. White arrows point towards diatom chains and black arrows point towards colonies of flagellates.