Metabarcoding and metatranscriptomic profiles of eukaryotic phytoplankton within coastal surface water off West Greenland and West Iceland. Metabarcoding and metatranscriptomic profiles of eukaryotic phytoplankton

The arctic is a rapidly changing environment, which has fundamental impact on the biodiversity, community composition and metabolic processes of phytoplankton species. Phytoplankton species are the key factor of primary production in the ocean and fulfill a variety of ecological functions. It is important to understand the changes and differences in biodiversity and correspondent ecological functions as size groups and taxa may have evolved different eco-evolutionary strategies. In this study we compared the molecular biodiversity of three plankton size fractions (micro-, nano-, and picoplankton) from ice influenced coastal waters off West Greenland with ice free coastal waters off West Iceland in their environmental context. Metatranscriptomic (mRNA) profiles of six genera (Dinophysis, Peridinium, and Scrippsiella and Chaetoceros, Pseudo-nitzschia, and Thalassiosira) of the microplankton identified potential metabolic strategies of these genera. Our results suggest that species with smaller cell size with a high diversity and total abundance have a high specialization and speciation to compensate for the potentially higher plasticity of the larger cell- size taxa. Consequently, with this particular structure of the phytoplankton competition for resources within the same environment may be avoided, however some species might have advantages in a changing phytoplankton communities and changing ecosystem.