Characterization of Algal Dissolved Organic Matter Utilized by Marine Sponges

Coral populations on reefs around the world continue to suffer catastrophic declines. As they die off, there has been a documented rise in the proliferation of sponges and turf algae as dominant reef features. With the expansion of marine sponge and algal populations, it is important to understand their interaction with the surrounding environment, shedding light on the potential consequences for the entire ecosystem. Emergent sponges containing high microbial abundances (HMA) of associated bacteria can feed on dissolved organic matter (DOM) from algae as they filter seawater. To investigate cycling of DOM production by macroalgae and subsequent uptake by sponges, a series of targeted and untargeted analytical analyses, both on the reef and in the laboratory, were employed to characterize algal DOM before and after passing through a sponge. Targeted analyses of bulk dissolved organic carbon (DOC) were correlated with dissolved free carbohydrates (DFCH) and dissolved free amine containing metabolites (DFA) using a combination of gas (GC-MS/MS) and liquid chromatography (LC-MS/MS) hyphenated approaches. In parallel, untargeted HRMS-MS metabolomics investigations were performed to begin to understand alterations to the DOM pool on a molecular level. Experimental design included both in situ sampling and laboratory incubation experiments of multiple brown macroalgae species and high/low microbial abundance (HMA)/(LMA) sponges. Results show distinct trends correlating emergent HMA sponges and LMA sponges with DOM modifications.

Presentation Preference: Poster

Primary Presenter: Courtney Clevenger, University North Carolina Wilmington (ctk6717@uncw.edu)

Authors:

Courtney Clevenger, University North Carolina Wilmington  (ctk6717@uncw.edu)

Zane Ritter, University North Carolina Wilmington  (zgr7619@uncw.edu)

Lydia Davis, University North Carolina Wilmington  (davisla@uncw.edu)

Kyler Sloan, University North Carolina Wilmington  (kms1532@uncw.edu)

Megan Laufer, University North Carolina Wilmington  (mcl8732@uncw.edu)

Christian Richter, University North Carolina Wilmington  (cr5868@uncw.edu)

Joseph Pawlik, University North Carolina Wilmington  (pawlikj@uncw.edu)

Winifred Johnson, University North Carolina Wilmington  (johnsonwm@uncw.edu)

Ralph Mead, University North Carolina Wilmington  (meadr@uncw.edu)

Wendy Strangman, University North Carolina Wilmington  (strangmanw@uncw.edu)