This three-year award will support U.S.-France cooperative research in biological oceanography between Lisa Campbell of the University of Hawaii and Daniel Vaulot of the University of Paris VI. The objective of their research is to develop useful probes for identification and enumeration of important picoeukaryotic algae. Picoeukaryotic algae are the very smallest eukaryotic phytoplankton and contribute a large percentage of primary production in tropical and subtropic oceans. The investigators will develop and apply oligonucleotide probes and immunochemical probes to cell surface antigens. Mutual benefits of this project include obtaining the best available probes to date and devising the best strategy to address the overall objectives. It is expected that results from this project will advance our knowledge of the composition and community structure of picoeukaryotic algae.