Monitored variables and data collected include: Chlorophyll and primary production data for each lake and year for which it was collected and analyzed. Most data files appear in the format of one file for each lake during each year, but some multiple year or multiple lake sets are available. Nutrient analysis including ammonia, soluble reactive phosphorus, total dissolved nitrogen, total dissolved phosphorus, and particulate nitogen/carbon/phosphorus, data is posted for each lake and year for which it was collected and analyzed. Most data files appear in the format of one file for each lake during each year, bust some multiple year or lake sets are available. Measurements taken at every meter or half meter, including temperature, dissolved oxygen, pH, conductivity, and PAR. Also included are base cations, anion, and alkalinity for select depths. Capture/recapture totals, species, length, and weight of lake trout (Salvelinus namaycush), arctic grayling (Thymallus arcticus), round whitefish (Prosopium cylindraceum), burbot (Lota lota), and arctic char (Salvelinus alpinus). Zooplankton, microplankton, and picoplankton water column profiles and densities for lakes sampled during a given year. Bacterial counts and composition for Toolik Lake. Carbon and nitrogen isotopic signatures in biotic and abiotic samples. Dissolved Organic Carbon, Dissolved Gasses, and Lake Met. Toolik Inlet Discharge.