There is an urgent need for techniques to identify and quantify many types of small marine eukaryotes. Current knowledge of population dynamics is limited to a small percentage of the microbial community, due to the difficulties involved with culturing and identifying marine microeukaryotes. These problems in community analysis can be resolved with tools that are being developed through advances in molecular biology. Objectives of the investigation are to develop non- radioactive probes for rapid analyses of populations of yeasts. Three types of probes will be developed to determine the relative abundance of yeast populations within the eukaryotic community: a universal eukaryote probe, a universal yeast probe and species specific probes. Dr. Fell will experiment with chemiluminescent, fluorescent and biotin labeled probes. These probes will be tested in the laboratory and in the field.