README FILE: Phytoplankton identification P.I.: Jackie Grebmeier 10515 Research Dr. Suite 100, Bldg. A Marine Biochemistry & Ecology Dept. of Ecology & Evolutionary Biology University of Tennessee, Knoxville Knoxville, TN 37932 tel: +1 865.974.2592 fax: +1 865.974.7896 email: jgrebmei@utk.edu Funding Source/Grant number: NSF OPP 0125082 Subaward: Dr. Mickle Flint, Shirshov Institute of Oceanology, Moscow, Russia, email: m_flint m_flint@orc.ru and Dr. Irina Sukhanova Phytoplankton with cell size larger than 2-3 µm were analyzed for taxonomic composition, size composition including colonies size, numbers and biomass and vertical distribution of all the parameters. Phytoplankton cell count samples were collected from the surface and the subsurface chlorophyll maximum at experimental and optical stations during the SBI 2002 spring (HLY0201) and summer (HLY0203) cruises. 130 ml samples for phytoplankton counts were collected by Niskin water bottles on the CTD, preserved and stored in plastic bottles. In 2002 the samples were preserved with Lugol. This fixative maintains the sufficient integrity of all components of phytoplankton, except for coccolitophores. During the summer HLY0203 cruise, another 130 ml samples of water were collected for cocclitophores counting and these were preserved with 0.2% neutral formaldehyde. The samples were processed in 8 months after collected. Dimensions of all phytoplankton cells in processed subsample were measured. Biovolume of the cells was calculated by the method of geometric similarity and converted to carbon using the coefficients from Strathmann (1967) and Menden-Deuer & Lessard (2000). Strathmann R.R. Estimating the organic carbon content of phytoplankton from cell volume, cell area or plasma volume // Limnol. Oceanogr. 1967. V.12. _ 3. P. 411- 418 Menden-Deuer S., Lessard E.J. Carbon to volume relationships for dinoflagellates, diatoms, and other protist plankton // Limnol. Oceanogr. 2000. V.45. _ 3. P. 569- 579. .