Bacterioneuston Community Structure in the Southern Baltic Sea and Its Dependence on Meteorological Conditions

Abstract

The bacterial community in the sea surface microlayer (SML) (bacterioneuston) is exposed to unique physicochemical properties and stronger meteorological influences than the bacterial community in the underlying water (ULW) (bacterioplankton). Despite extensive research, however, the structuring factors of the bacterioneuston remain enigmatic. The aim of this study was to examine the effect of meteorological conditions on bacterioneuston and bacterioplankton community structures and to identify distinct, abundant, active bacterioneuston members. Nineteen bacterial assemblages from the SML and ULW of the southern Baltic Sea, sampled from 2006 to 2008, were compared. Single-strand conformation polymorphism (SSCP) fingerprints were analyzed to distinguish total (based on the 16S rRNA gene) and active (based on 16S rRNA) as well as nonattached and particle-attached bacterial assemblages. The nonattached communities of the SML and ULW were very similar overall (similarity: 47 to 99%; mean: 88%). As an exception, during low wind speeds and high radiation levels, the active bacterioneuston community increasingly differed from the active bacterioplankton community. In contrast, the particle-attached assemblages in the two compartments were generally less similar (similarity: 8 to 98%; mean: 62%), with a strong variability in the active communities that was solely related to wind speed. Both nonattached and particle-attached active members of the bacterioneuston, which were found exclusively in the SML, were related to environmental clones belonging to the Cyanobacteria, Bacteroidetes, and Alpha-, Beta-, and Gammaproteobacteria originally found in diverse habitats, but especially in water columns. These results suggest that bacterioneuston communities are strongly influenced by the ULW but that specific meteorological conditions favor the development of distinctive populations in the air-water interface.

Enrichment of microbial abundance in the sea-surface microlayer over a coral reef: implications for biogeochemical cycles in reef ecosystems

“…Although we did not measure particulate organic matter in this study, a higher coral coverage can mean a higher release of mucus derived particles into ambient water, which may be the reason why the EF is higher in the HCC site. Changes in bacterial community composition between the SML and SSW are reported to be stronger in the particle-attached than the non-attached bacteria (Stolle et al 2011). Thus, a distinct bacterial community may exist in the SML at the HCC site.…”

High‐throughput sequencing reveals neustonic and planktonic microbial eukaryote diversity in coastal waters

“…, , Stolle et al. ), and more recently high‐throughput sequencing (see review Cunliffe et al. , Taylor et al.…”

SISI: A New Device for In Situ Incubations at the Ocean Surface

“…Our observations fit with findings from Pomeroy, Sheldon and Sheldon [40] of a 23% increase in bacterial cell numbers in dark-incubated SML samples from the start to end of the incubation period for Pacific station 9 (Supplement Data S2: Cell counts St.9 SISI). One reason for this might be that SML microorganisms in closed-bottle incubations particularly benefit from low turbulence and minimal impact from waves and wind, which are crucial factors that would naturally affect them [10,11]. We suggest that incubation times should be adjusted to the minimum, which produces reasonable rates of O 2 turnover but reduces containment errors, such as enormous increases in cell numbers.…”

“…In addition, due to the accumulation of organic matter and surface-active molecules [4,5], the SML constitutes a unique biofilm-like habitat for microorganisms [3,6]. Life within the SML is heavily influenced by a range of "extreme" conditions such as enhanced solar and ultraviolet (UV) radiation [7][8][9], strong wind-wave dynamics [10,11] and the accumulation of pollutants [12]. Heterotrophic microbes in particular benefit from the enrichment of organic substrates, allowing them to thrive and form distinctive communities within the SML compared to the underlying water [13,14].…”