Microbes play many vital roles in the oceans. They are crucial in the transformation and cycling of elements such as carbon, nitrogen, and sulfur; they are fundamental components of marine food webs, and although small, their activities affect global biogeochemical cycles and help regulate the global climate. Using cutting-edge technologies, faculty in the department study the diversity, structure, and function of microbial communities; how microbes affect the transformations and cycling of elements such as nitrogen and sulfur; and the ecological interactions between viruses, bacteria, and phytoplankton.