Water samples had been taken at 25 stations during MSM21-3 cruise at depths of about 10 m with a rosette sampler at the coasts of West Greenland (Uummannaq Fjord, Vaigat Strait, Disko Bay) and West Iceland (Arnafjördur, Breidafjördur, Faxaflóe) between 2012-07-27 and 2012-08-08. At 16 stations also deeper water samples had been taken at depths between 40m and 625m. All samples were size fractionated to enrich Micro- (20-50 µm), Nano- (3-20 µm) and Picoplankton (0.2-3 µm). 12 microplancton samples were selected and RNA-Seq technology applied on an Illumina HiSeq 2500 sequencer to obtain metatransriptomic profiles.