HR: 09:20h
AN: OS31B-01    [Abstracts]
TI: Marine Snow and Gels: Hot Spots of Biogeochemical Cycling, Biological Activity, and Sedimentation in the Sea
AU: * Alldredge, A L
EM: alldredg@lifesci.ucsb.edu
AF: Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106 United States
AB: Much of the organic carbon sequestered in the deep sea and ocean bottom sediments as relatively rare, large detrital particles generically known as marine snow. Because they are enriched in organic matter, microbes, and nutrients, these large particles also serve as hot spots for biological and chemical process in the water column. Recent evidence reveals that abundant carbohydrate gel particles in the ocean, formed from the dissolved exudates of phytoplankton and bacteria, are intricately involved in the formation of marine snow. These discoveries are changing the way we conceptualize the pelagic zone on small scales. We no longer imagine seawater as a relatively homogeneous fluid in which float a spectrum of dispersed molecules, particles, and organisms, but instead see it as a rich hydrated matrix of transparent organic gels, detritus, and cob-web like surfaces which provide microscale physical, chemical, and biological structure. This talk will focus on the origins, fate, and significance of marine snow and gels in the sea, including their role in carbon cycling, sedimentation and carbon flux , food webs, and chemical and biological transformation.
DE: 4806 Carbon cycling
DE: 4840 Microbiology
DE: 4863 Sedimentation
DE: 4800 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting