QUANTIFYING MULTITROPHIC CARBON FLUX NETWORKS OF THE BERMUDA ATLANTIC TIME-SERIES

Modern sampling and analytical advances have produced a wealth of high-resolution data on the composition of microbial ecosystems. For the Bermuda Atlantic Time-series Study (BATS), this includes DNA sequences, cell counts, and metabolite concentrations. However, direct observation of microbial interactions, essential for a quantitative, mechanistic understanding, remains challenging and generally requires inference. To address this, we integrated BATS data of a 4-year time series into the mechanistic ecosystem model FluxNet, that quantifies interactions, specifically carbon fluxes, across different trophic levels. We simulate the ~40 most abundant species across key biological compartments (heterotrophic bacteria, phytoplankton, zooplankton, heterotrophic protists, and particulate and dissolved organic matter), and quantify complex multitrophic, multispecies interactions by estimating carbon fluxes between all species and compartments. By dividing the upper 200 m of the water column into three dynamically-varying vertical layers - surface, deep chlorophyll maximum, and upper mesopelagic - the model provides insights into carbon transfer between layers and carbon export to the deep ocean. This three-layer, mass-balanced, mechanistically-constrained model generates quantitative flux estimates for each interaction and time point across species and vertical layers, making it a powerful tool for unraveling the complex dynamics of microbial ecosystems in the surface ocean.

Presentation Preference: Oral

Primary Presenter: Falk Eigemann, Technical University Berlin (falkeigemann@gmail.com)

Authors:

Falk Eigemann, Technical University Berlin  (eigemann@tu-berlin.de)

Jutta Hoffmann, Technical University Berlin  (jutta.hoffmann@tu-berlin.de)

Leocadio Blanco-Bercial, ASU BIOS  (Leocadio@asu.edu)

Fabian Wittmers, Marine Biological Laboratory, Woods Hole  (fwittmers@mbl.edu)

Kevin Vergin, Microbialdnaanalytics  (kevin@microbialdnaanalytics.com)

Krista Longnecker, Woods Hole Oceanographic Institution (WHOI)  (klongnecker@whoi.edu)

Alexandra Worden, Marine Biological Laboratory, Woods Hole  (azworden@mbl.edu)

Stephen Giovannoni, Oregon State University  (steve.giovannoni@oregonstate.edu)

Elizabeth Kujawinski, Woods Hole Oceanographic Institution (WHOI)  (ekujawinski@whoi.edu)

Ferdi Hellweger, Technical University Berlin  (ferdi.hellweger@tu-berlin.de)