Coastal seawater hosts diverse bacteria that perform various functions, such as decomposing organic matter, nitrogen cycling, and serving as food for other organisms. In addition to the ecological importance, bacteria present in seawater can also affect human health if they are inhaled, ingested or get in contact with skin. Understanding the bacterial community in coastal seawater is therefore essential for both ecological and public health reasons. The surf zone, where sea spray aerosols are formed, is of particular interest due to the potential for increased bacterial concentrations and interactions with beachgoers. This study aimed to investigate the bacterial community and their function in the surf zone. We collected 72 surface seawater samples from a recreational beach in Ostend, Belgium from March 2018 to November 2019. Bacterial communities were analyzed using full-length 16S rDNA nanopore sequencing. Potential bacterial functions were determined using the FAPROTAX database. Biotic and abiotic factors, obtained from the “Ocean Productivity” and “Meetnet Vlaamse Banken” databases, were examined as the drivers of bacterial community and function using the Mantel test. The results showed that spring seawater had a higher number of unique taxa at the family level. The relative abundance of Rhodobacteraceae and dark sulfur oxidation function were higher in spring seawater, mostly driven by Chl a, indicating a higher potential for the formation of dimethylsulphide (DMS) and therefore the formation of secondary marine aerosols and cloud condensation nuclei.

Primary Presenter: Yunmeng Li, Flanders Marine Institute (yunmeng.li@vliz.be)

Authors:

Yunmeng Li, Flanders Marine Institute  (yunmeng.li@vliz.be)

Emmanuel Van Acker, Ghent University  (emmanuel_van_acker@hotmail.com)

Colin Janssen, Ghent University  (colin.janssen@ugent.be)

Jana Asselman, Ghent University  (jana.asselman@ugent.be)

Maarten De Rijcke, Flanders Marine Institute   (maarten.de.rijcke@vliz.be)