The Cornell Biological Field Station (CBFS) serves as a primary field site for aquatic research at Cornell University (more information can be found at http://www.dnr.cornell.edu/fieldst/cbfs.htm) and is part of the Department of Natural Resources, College of Agriculture and Life Sciences. The centerpiece of the station's research program is a 50-year database on the food web of Oneida Lake, New York, that has been collected with support from the Cornell University Brown Endowment and from the New York State Department of Environmental Conservation. The data are collected by personnel from the Cornell Biological Field Station and include limnology, benthos, zooplankton, phytoplankton, and fish survey data, primarily from Oneida Lake and spanning 1957 to the present. This data package contains results of phytoplankton surveys of Oneida Lake, New York between 1975 - 1995. The primary table gives densities of 153 phytoplankton taxa identified in samples collected from five standard sites. Supplemental tables provide explanations of the taxonomic codes used in the primary table as well as geographic coordinates for the sampling sites. In years subsequent to 1995, phytoplankton samples were processed by an environmental consulting company. These data are not published here; please contact the data owners for more information.