Quantifying rates of primary production and respiration is fundamental to understanding ecosystem function. This study utilized high-frequency time series, buoy-based sensor data to estimate daily primary production and respiration rates during the summers of 2012–2015 in southern Green Bay, Lake Michigan. Highly coherent diel oscillations of dissolved oxygen concentrations in epilimnetic waters were commonly observed for much of the summer via 30-min time intervals from the GLOS buoy (NOAA 45014) sensor array.