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: 9:00:00 AM

Location: Aztec

Urban-Rich, J, , Environmental and Coastal Ocean Studies, UMASS Boston, Boston, MA, USA, juanita.urban-rich@umb.edu

THE LEAKY PELLET: WHAT DOES IT MEAN FOR CARBON CYCLING?

Traditionally zooplankton fecal pellets have been considered important in particulate organic carbon transport from the euphotic zone or as a food source for other copepods. Relatively few studies have been conducted on the release of dissolved organic carbon from fecal pellets. Preliminary results from laboratory experiment conducted in Bermuda indicate that greater than fifty percent of the carbon within fecal pellets may be in the dissolved form. While attached bacteria may use much of this material some is lost to the surrounding water. Studies conducted in the Greenland Sea and Balsfjord, Norway indicates that dissolved organic carbon can be released from sinking pellets for several days. The implications of the dissolved fraction in pellets along with the time scales of dissolved organic matter release will be discussed relative to carbon cycling. I propose that sinking pellets and zooplankton in general are important sources of dissolved organic matter and provide food for the microbial food web. I suggest that pellets stimulate carbon retention within surface water or flux via dissolved organic carbon.

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Aquatic Sciences Meeting, Albuquerque 2001

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