This award renews support for the Provasoli-Guillard National Center for Culture of Marine Phytoplankton (CCMP), a service collection that serves as a central repository to receive, maintain and distribute living cultures of marine phytoplankton. Oceans, seas, bays, estuaries, and other marine habitats cover 71% of the Earth's surface. The marine phytoplankton found in these environments account for approximately 40% of the Earth's photosynthesis and provide food (directly or indirectly) for most marine animals. The CCMP is the world's largest culture collection dedicated to marine phytoplankton. The Center currently holds approximately 2000 strains of single-celled algae. During the past 5 years, the CCMP's holdings have grown by about 25% while it has provided approximately 8000 cultures to scientists and aquaculturists at a modest charge. Strains are maintained through serial culture or are held in frozen form over liquid nitrogen. The CCMP maintains a website that provides information about the strains in its collection and includes digital images of many strains, taxonomic information, protocols for culturing and cryopreservation of strains, literature references and links to other relevant online sources of information such as GENBANK.