A very large data set was obtained on the nearshore environment of Lake Michigan during 1972. The data set is probably unique in that samples were collected and analyzed for a number of physical-chemical parameters and for phytoplankton standing crop and species composition. Phytoplankton identified during the study totaled 431 taxa of which 306 were diatoms, which serves to illustrate the magnitude of available data. Results are presented for eleven different transects sampled in April and for three of these transects which were sampled in September. In addition, transects for the St. Joseph, Kalamazoo, and Grand Rivers were sampled four or five times and each of these rivers were sampled from seven to eleven times in July. Data collected with depth presented in this report include water temperature. Secchi disc transparency, pH, specific conductance, dissolved reactive silica, nitrate nitrogen, and total phosphorus as physical-chemical variables. On transects samples with depth were obtained at stations 0, .2, .8, 1.6, 3.2, 6.4, 13, 26, and 52 km from shore, although the stations from 13 to 52 km were not sampled on every transect. Data related to phytoplankton include species composition and abundance, species diversity, chlorophyll a, and rates of carbon fixation. All these data were obtained only at 2 meters.
