Hi! My name is Alex Snedeker and I am a rising junior at the University of North Carolina at Chapel Hill majoring in Environmental Science and minoring in Marine Science. This summer I am working with Dr. Tracy Villareal to explore diatom diazotroph associations (DDAs) in the northern Gulf of Mexico. These associations, formed between diatom genera such as Hemiaulus and Rhizosolenia and the nitrogen-fixing endosymbiotic bacteria Richelia intracellularis, can potentially help supply bioavailable sources of nitrogen to phytoplankton communities in oligotrophic waters. In past studies, blooms of these organisms have been found in areas influenced by freshwater plumes and have been shown to make important contributions to nitrogen cycling and primary production. My work involves determining the distributions of DDAs involving both Hemiaulus and Rhizosolenia as part of a month-long research cruise throughout the northern Gulf of Mexico, as well as what factors influence their abundance. I will also determine whether the Mississippi River plume fuels the growth of DDAs and what effects this may have on overall nitrogen cycling in the Gulf.