Dr. Guillard's research interests are physiology and ecology of phytoplankton; influence of environmental factors, especially trace metals, on the growth of marine phytoplankton; life cycles and systematics of diatoms; speciation in planktonic diatoms; phytoplankton as food for marine animals; systematics and physiological ecology of marine ultraplankton. Bigelow Laboratory's Provasoli-Guillard National Center for Culture of Marine Phytoplankton was dedicated in honor of Dr. Guillard and Dr. Luigi Provosoli for their pioneering achievements in the culture of marine phytoplankton.