Estimating variability of microeukaryotic community during summer at Potter Cove (Antarctica), using a multiprimer approach

Abstract

Potter Cove (King George Island, Antarctica) is located in the northern section of the Western Antarctic Peninsula (WAP) region. There, environmental conditions show high seasonal variability related to sea ice cover and glacier meltwater input, for example. These factors may regulate irradiance regimes and nutrient input, thereby governing phytoplankton growth as well as its community composition. In the present study, we analyzed microeukariotic succession over one summer season, applying Denaturing gradient gel electrophoresis (DGGE), clone libraries, and 18SrRNA gene sequencing, based on a set of primer for (general) eukaryotes, diatoms, and dinoflagellates. Temperature, salinity, stratification, turbidity, and nutrients were also measured to determine the importance of these environmental drivers for protist performance. Different areas in the cove were sampled. The inner part of the cove was found to be highly influenced by glacier meltwater input during summer. Cluster analyses of eukaryote, diatom, and dinoflagellate DGGE fingerprints showed different clustering patterns, yet for all groups, time was the main shaping factor. Moreover, one of the glacier-influenced samples clustered separately from another taken on the same sampling day, coinciding with a low salinity and high turbidity event. In addition, diatom and dinoflagellate-specific fingerprints revealed a separate cluster for surface waters. The sequence analysis showed high abundances of Alveolata and Haptophytes (Pheocystis). Overall, Potter Cove is suggested to host a dynamic microeukaryotic community due to high temporal variability and some glacier influence.