New Hampshire boasts what is considered by many to be one of the richest coastal estuary systems in the country. In addition to 18 miles of ocean coastline, New Hampshire has 230 miles of sensitive inland tidal shoreline, consisting of bays, tidal rivers and salt marsh systems. The Great Bay Estuary System is comprised of nearly 150 miles of tidal shore land; approximately 4,500 acres of tidal waters and wetlands, along with 3,000 acres of coastal land, comprise the Great Bay National Estuarine Research Reserve.