Carbon cycles & marine food webs – considering picoeukaryote roles
Alexandra Worden, Ph.D.
Rosenstiel School, University of Miami
Tuesday, 3:00 PM
August 22, 2006
For the past several decades picophytoplankton (<2 m cell diameter) have been recognized as major primary producers in marine ecosystems. Recognition of the prokaryotic groups, Prochlorococcus and Synechococcus, as both widespread and highly abundant primary producers was expedited by their easy identification using flow cytometry, although population controls have remained difficult to clarify. In contrast, the global importance of eukaryotic picophytoplankton has only recently been fully realized. Picoeukaryotes are composed of the smallest free-living eukaryotes known to date and utilize a variety of trophic modes. We study the ecology and diversity of these organisms in coastal and open ocean environments, from the euphotic zone to the deep ocean. Current work on photosynthetic picoeukaryotes shows novel genomic features as well as biogeochemical importance, with significant contributions to both picophytoplanktonic primary production and trophic transfer of carbon.