EFFECTS OF STORM SURGES ON SALT MARSH MICROBIAL COMMUNITIES

Microbial communities in salt marshes play a central role in nutrient cycling, primary production, and the resilience of the ecosystem. The present study examines the impact of storm surges on microbial community dynamics. The research was conducted on experimental islands in the back-barrier tidal flats of Spiekeroog, Germany, constructed in 2014 with different height levels corresponding to salt marsh zones (pioneer, lower, and upper). Samples were obtained from islands initially devoid of vegetation and from that were transplanted with lower salt marsh sediments and plants. Sampling was conducted in prior to the storm season (September 2022), immediately after (March 2023) and following a recovery time of five months (August 2023). Aiming at assessing microbial resistance, and recovery, we analyzed 16S prokaryotic DNA, 18S eukaryotic DNA, pigment composition, prokaryotic abundance, and extracellular polymeric substances. Results show differences in terms of resistance and recovery success in algae and bacterial biomass between the initially bare and transplanted islands. The lower the elevation the less resistant was the microbial community in terms of biomass, in addition the transplanted islands always showed a higher resistance than initially bare islands. The storm surges caused community composition to change in dependence to elevation and initial vegetation. The present study offers insights into the microbial dynamics of the Wadden Sea, elucidating their response to large-scale disturbances and enhancing our comprehension of coastal ecosystems.

Presentation Preference: Oral

Primary Presenter: Mike Smykala, Carl von Ossietzky Universität Oldenburg (mike.jan.smykala@uni-oldenburg.de)

Authors:

Mike Smykala, Carl von Ossietzky Universität Oldenburg  (mike.jan.smykala@uni-oldenburg.de)

Bert Engelen, Carl von Ossietzky Universität Oldenburg  (bert.engelen@uol.de)

Birte Matthiessen, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel  (bmatthiessen@geomar.de)

Stefanie Moorthie, Carl von Ossietzky Universität Oldenburg  (stefanie.moorthie@uol.de)