The Great Bay Estuary is a tidally dominated system with the drainage confluence of seven major rivers, several small creeks and their tributaries, and ocean water from the Gulf of Maine. "Great Bay Estuary" generally refers to the entire estuarine system composed of Great and Little Bays and the Piscataqua River. "Great Bay" refers only to the broad inner bay which begins at Furbur Strait and is the location of the Great Bay National Estuarine Research Reserve. Except for one, all the major tributaries to the Great Bay Estuary carry treated sewage effluent into the Estuary, contributing bacteria and nutrients to estuarine waters. Since European settlement of the area, the Estuary has experienced a series of contamination loadings including massive sawdust input, fish waste, untreated sewage, and mill and tannery chemicals. Because of the strong tidal influence, with high tidal volume and rapid currents, much of the contamination released into the Estuary over the years has very quickly been flushed out of the system. Though not currently heavily contaminated, the Great Bay Estuary exhibits warning signs of its fragility including shellfishing closures, loss of eelgrass habitat, and increasing shoreline development.
* Source: Short, F.T. 1992. (ed.) The Ecology of the Great Bay Estuary, New Hampshire and Maine: An Estuarine Profile and Bibliography. NOAA - Coastal Ocean Program Publ. 222pp.
