Ecology and diversity of heterotrophic protists in the Columbia River coastal margin

Heterotrophic protists, a diverse group of microbial eukaryotes characterized by great morphological variability and extensive taxonomic representation, play important ecological roles in aquatic food webs as prey and predators. Difficulty in heterotrophic protist identification has often resulted in lumping them into broad groups, but there is a crucial need to develop methods that increase the spatial and temporal resolution of observations applied to particular organisms in order to discover the drivers of population structure and ecological function. This research characterizes the spatiotemporal distribution of heterotrophic protist assemblages in the Columbia River coastal margin (including the tidal freshwater reaches of the river, the chemical estuary, and the river plume in the adjacent coastal ocean) using DNA sequence and morphological approaches.