Biogeochemistry and Polymer Physics of Seawater Gels: A New Paradigm for the Microbial Loop and Global Element Cycles

University Of Washington, Seattle WA

Investigators

Abstract

0120579 Verdugo The objective of the proposed research is to test the hypothesis that a major fraction of dissolved organic matter in seawater occurs as self-assembled polymer gels with unique properties that differ from those of their constituent macromolecules or from rigid colloids of comparable size. These properties affect bioavailability of the organic constituents in this colloidal matter. The hypothesis will be tested in parallel laboratory and field experiments involving biophysics, biogeochemistry and marine microbiology. The validity of the hypothesis is tested by addressing five subquestions which include: (1) What are the spatial and temporal distributions of the gel? (2) What are the chemical properties? (3) How are the physics of marine gels related to their sources and reactions? (4) What are the biological sources? (5) What biodegradation processes alter or remove the gels? This research could help explain how organic polymer gels affect the function of the oceans microbial loop, and hence the marine food web and global carbon cycle.