Aquatic Sciences Meeting, Albuquerque 2001

SS12 To Sink or Not to Sink: The Role of Zooplankton for Export and Retention of Fecal Pellets and Aggregates (Environmental Connections)

Date: Friday, February 16, 2001, Time: 9:30:00 AM

Location: Aztec

Goldthwait, S, A, University of California, Santa Barbara, USA, goldthwa@lifesci.ucsb.edu

Yen, J, , Georgia Institute of Technology, Atlanta, USA, jeannette.yen@biology.gatech.edu

Alldredge, A, L, University of California, Santa Barbara, USA, alldredg@lifesci.ucsb.edu

IMPACT OF EUPHAUSIID SWIMMING ON MARINE SNOW SIZE AND FLUX

Sinking of marine snow is the major mechanism of carbon transport from surface waters to the seafloor. Processes altering the abundance or size of marine snow influence carbon transport and food availability to pelagic and benthic organisms. Zooplankton are known to affect particle dynamics through sloppy feeding, ingestion of marine snow, and fecal pellet production. We explored a new mechanism by which zooplankton alter carbon transport: physical fragmentation of marine snow. The shear created around the rapidly moving appendages of Euphausia pacifica is capable of fragmenting a single aggregate into multiple, smaller aggregates. The reduced size and slower sinking rate of the daughter aggregates may increase their residence time in the water column, promoting decomposition and decreasing particle flux to depth. To determine the importance of this process tethered and free-swimming euphausiids were videotaped in the presence of marine snow. Image analysis was used to characterize the size class of particles fragmented, the daughter particles produced, and the area of influence around a single euphausiid.

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Aquatic Sciences Meeting, Albuquerque 2001

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