Eukaryotic community composition in the sea surface microlayer across an east-west transect in the Mediterranean Sea
|Author(s)||Zancker Birthe1, 2, Cunliffe Michael2, 3, Engel Anja1|
|Affiliation(s)||1 : GEOMAR, Helmholtz Centre for Ocean Research Kiel, 24105 Kiel, Germany
2 : Marine Biological Association of the UK, Plymouth, PL1 2PB, United Kingdom
3 : School of Biological and Marine Sciences, University of Plymouth, PL4 8AA, United Kingdom
|Source||Biogeosciences (1726-4189) (Copernicus GmbH), 2021 , Vol. 18 , N. 6 , P. 2107-2118|
|Note||Special issue | Atmospheric deposition in the low-nutrient-low-chlorophyll (LNLC) ocean: effects on marine life today and in the future (BG/ACP inter-journal SI)(BG/ACP inter-journal SI) Editor(s): Christine Klaas, Cecile Guieu, Karine Desboeufs, Jan-Berend Stuut, Mark Moore, Paraskevi Pitta, Silvia Becagli, and Chiara Santinelli Special issue jointly organized between Biogeosciences and Atmospheric Chemistry and Physics|
The sea surface microlayer (SML) represents the boundary layer at the air–sea interface. Microbial eukaryotes in the SML potentially influence air–sea gas exchange directly by taking up and producing gases and indirectly by excreting and degrading organic matter, which may modify the viscoelastic properties of the SML. However, little is known about the distribution of microbial eukaryotes in the SML. We studied the composition of the microbial community, transparent exopolymer particles and polysaccharides in the SML during the PEACETIME cruise along a west–east transect in the Mediterranean Sea, covering the western basin, Tyrrhenian Sea and Ionian Sea. At the stations located in the Ionian Sea, fungi – likely of continental origin and delivered by atmospheric deposition – were found in high relative abundances, making up a significant proportion of the sequences recovered. Concomitantly, bacterial and picophytoplankton counts decreased from west to east, while transparent exopolymer particle (TEP) abundance and total carbohydrate (TCHO) concentrations remained constant in all basins. Our results suggest that the presence of substrates for fungi, such as Cladosporium, known to take up phytoplankton-derived polysaccharides, in combination with decreased substrate competition by bacteria, might favor fungal dominance in the neuston of the Ionian Sea and other low-nutrient, low-chlorophyll (LNLC) regions.