9400698 ALLDREDGE A new class of large, abundant particles has recently been discovered which exist as transparent films, sheets and strings in seawater. These transparent exopolymer particles (TEP) appear to be formed from dissolved polysaccharides excreted by phytoplankton and bacteria. The existence of microbial exudates acting as large, discrete particles rather than as dissolved molecules as a coatings on other particles has far reaching implications for carbon cycling, microbial processes, food web structure, and transformations of organic matter in the ocean, but because of their recent discovery, the significance of these particles is largely unknown. This research will conduct preliminary studies to elucidate the potential significance of these invisible particles to several oceanographic processes. These studies will 1) determine how TEP is formed and what factors most influence formation, 2) determine which taxa are the most significant contributors to TEP formation, 3) establish whether TEP serves as a food source or inhabits feeding of zooplankton, 4) investigate degradation of TEP by bacteria, and 5) examine seasonality of TEP in nature.
