Long-term water quality monitoring in the Altamaha, Doboy and Sapelo sounds and the Duplin River near Sapelo Island, Georgia from November 2013 to December 2022

Water samples were collected on Georgia Coastal Ecosystems LTER oceanographic monitoring cruises from November 2012 through December 2022. Monthly samples were collected from GCE 6 (high and low tide) and GCE 7 (high tide). Quarterly samples were collected from the remaining GCE sites and AL-02, the Altamaha River oceanic end-member station. Concentrations of the following were measured using standard analytical methods: dissolved nutrients (phosphate, nitrate+nitrite, ammonium, silicate), dissolved organics (carbon, nitrogen, phosphorus) and particulate carbon and nitrogen, chlorophyll, phaeopigments, total suspended solids and loss on ignition.