The Release and Bioavailability of Macroalgal Derived Dissolved Organic Carbon

Macroalgal growth (net primary production; NPP) occurs at a high areal rate compared to terrestrial ecosystems and other vegetated coastal habitats. This study aims to quantify the amount and rates of dissolved organic carbon (DOC) produced by macroalgae during growth and the subsequent biolability of this DOC in the surface ocean environment.  During growth, macroalgae sequester C as biomass but also releasing some as DOC. The fraction of this DOC that persists in the environment long enough to be sequestered in deeper ocean waters is poorly defined. Here, sugar kelp (Laminaria saccharina), rockweed (Fucus distichus and Ascophyllum nodosum), Ulva lactuca, Gracilaria hayi, Gracilaria parvispora, and a Spermothamnion species were grown and analyzed for DOC release and subsequent resistance of the DOC to biodegradation. Results provide knowledge on algal C cycling, helping to elucidate the potential role of macroalgae in C sequestration and broader biogeochemical cycles.

Primary Presenter: Cassandra Vongrej, Northeastern University (vongrej.c@northeastern.edu)

Authors:

Cassandra Vongrej, Northeastern University  (vongrej.c@northeastern.edu)

Jessica Gould, Northeastern University  (gould.je@northeastern.edu)

Lixin Zhu, Northeastern University  (zlxouc@gmail.com)

Aunjoli Das, Northeastern University  (das.a@northeastern.edu)

Aron Stubbins, Northeastern University  (a.stubbins@northeastern.edu)