In situ water quality assessment has become an important source of data for monitoring, research and management activities in estuaries nationwide. As part of the National Estuarine Research Reserve System, the Great Bay System-Wide Monitoring Program (SWMP) produces in situ water quality data for four sites in and around Great Bay. This project extends the SWMP program to include year-round in situ data for a station at the University of New Hampshire Coastal Marine Lab pier at the mouth of the Piscataqua River and summmer data for a station in the Salmon Falls (SF) River. This suite of stations provides a comprehensive in situ sampling array that monitors the major rivers and open estuary locations within the Great Bay estuarine system.