Variability of protistan and bacterial communities in two Arctic fjords (Spitsbergen)

• Published in: Polar biology Vol. 33; no. 11; pp. 1521 - 1536
• Main Authors: Piquet, A. M.-T, Scheepens, J. F, Bolhuis, H, Wiencke, C, Buma, A. G. J
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.11.2010; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Aquatic ecology; Aquatic resources; Bacteria; Bathymetry; Biological and medical sciences; Biomedical and Life Sciences; Climate change; Ecology; Ethylenediaminetetraacetic acid; Fjords; Fresh water; Fundamental and applied biological sciences. Psychology; Harbors; Life Sciences; Light penetration; Marine biology; Meltwater; Microbial ecology; Microbiology; Microorganisms; Oceanography; Original Paper; Particular ecosystems; Plant Sciences; RNA; Salinity; Sediments (Geology); Summer; Surface water; Synecology; Turbidity; Various environments (extraatmospheric space, air, water); Water properties; Zoology; Arctic Region; Arctic Ocean; PNE, Norway, Svalbard, Spitsbergen; PNE, Norway, Svalbard, Spitsbergen, Ny-Aalesund, Kongsfjorden; PN, Arctic; Krossfjorden; Climate change; Kongsfjorden; Polar; Marine microbes; Sequencing; Meltwater; DGGE; Spitsbergen; Sequenceing; Dynamical climatology; Marine environment; Fjord; Polar region; Microbial community
• ISSN: 0722-4060; 1432-2056
• DOI: 10.1007/s00300-010-0841-9

Krossfjorden and Kongsfjorden are Arctic fjords on the western side of Spitsbergen. These fjords share a common mouth to the open sea, and both are influenced by the input of sediment-rich glacial meltwater leading to decreased surface salinity, increased turbidity and decreased light penetration during summer. Earlier classical taxonomic studies had described the pelagic protistan composition of the Kongsfjorden during summer, revealing the dominance of flagellates of often unresolved taxonomic origin. Only little information existed on microbial eukaryote composition of the Krossfjorden as well as the bacterial composition of both fjords. The aim of the present study was to analyze and compare surface summertime protistan and bacterial communities in both fjords, using molecular approaches (16S and 18S rRNA DGGE, sequencing). Samples were collected three times a week from the central Kongsfjorden over a 1-month period. Additionally, 10 marine and 2 freshwater sites were sampled within a 1-week period in both Kongsfjorden and Krossfjorden. The central Kongsfjorden revealed a relatively stable protistan community over time with dinoflagellates, chlorophytes and small heterotrophs dominating. In contrast, the bacterial community varied over time and appeared to be correlated with the inflow of glacial meltwater. The Kongsfjorden and Krossfjorden were found to harbor distinctive bacterial and eukaryotic communities. We speculate that differences in glacial meltwater composition and fjord bathymetry affect the surface water properties and therefore the observed spatial variability in the community fingerprints.