Department of Energy Coastal Research Initiative Act This bill directs the Office of Science of the Department of Energy to carry out a research program to enhance the understanding of coastal ecosystems. In carrying out the program, the office must prioritize efforts to enhance the collection of observational data and shall develop models to analyze the ecological, biogeochemical, hydrological, and physical processes that interact in coastal zones. The office shall establish an integrated system of geographically diverse field research sites in order to improve the quantity and quality of observational data and that encompass the major land-water interfaces of the United States, including the Great Lakes region, the Pacific coast, the Atlantic coast, the Arctic, and the Gulf Coast.