Abstract: Diatom data from eastern side of Antarctic Peninsula: This file includes quantitative diatom data for surface samples collected on numerous cruises to the eastern side of the Antarctic Peninsula, including NBP0003, NBP0107, LMG0502, NBP0603, and NBP1203. Samples were collected using a variety of tools including Smith-McIntyre Grab, Kasten Core and Jumbo Kasten Core. These data were generated by Amy Leventer (aleventer@colgate.edu) and undergraduate students at Colgate University. All questions regarding the specifics of these data should be directed to Amy Leventer. Quantitative diatom slides were prepared according to the settling technique of Scherer (1995). Cover slips were adhered to the slides using Norland Optical Adhesive #61. Slides were observed under Olympus CX31, BX50 and BX60, and Zeiss Primo Star light microscopes, using a 100X oil immersion objective for a total magnification of 1000X. A minimum of 400 valves or 10 transects was counted for each slide, depending on the absolute diatom abundance. Valves were only counted if >50% complete. Diatoms were identified to species level when possible (Crosta et al., 2005; Armand et al., 2005; Cefarelli et al., 2010). Armand, L.K., X. Crosta, O. Romero, J. J. Pichon (2005), The biogeography of major diatom taxa in Southern Ocean sediments: 1. Sea ice related species, Paleogeography, Paleoclimatology, Paleoecology, 223, 93-126. Cefarelli, A.O., M. E. Ferrario, G. O. Almandoz, A. G. Atencio, R. Akselman, M. Vernet (2010), Diversity of the diatom genus Fragilariopsis in the Argentine Sea and Antarctic waters: morphology, distribution and abundance, Polar Biology, 33(2), 1463-1484. Crosta, X., O. Romero, L. K. Armand, J. Pichon (2005), The biogeography of major diatom taxa in Southern Ocean sediments: 2. Open ocean related species, Palaeogeography, Palaeoclimatology, Palaeoecology, 223, 66-92. Scherer, R. P., A new method for the determination of absolute abundance of diatoms and other silt-sized sedimentary particles, J. Paleolimnol., 12, 171–178, 1995.