Our Region

Our Watershed and its Estuaries are truly special places

The Piscataqua Region watershed encompasses 52 communities (42 in NH and 10 in ME) as well as the drainage area for the Great Bay and Hampton-Seabrook estuaries. Click on the map to the right to see a full picture of our watershed. 

Estuaries are partially enclosed bodies of water along the coast where the saltwater of the ocean meets and mixes with the freshwater of rivers and streams. Estuaries and the lands surrounding them are places of transition – from land to sea and freshwater to saltwater. Estuaries are among the most productive habitats on Earth, creating more organic matter each year than comparably sized areas of forest, grassland, or agricultural land. The tidal, sheltered waters of estuaries also support unique communities of plants and animals especially adapted for life at the margin of the sea. The Great Bay and Hampton-Seabrook Estuaries have approximately 220 miles of estuarine shoreline between Maine in New Hampshire. Learn more about each of these estuaries, their critical habitats, species, and issues below.

Piscataqua Region Watershed

Critical Species

The critical species that have been identified as important to our estuaries include soft-shell clams, American oysters, Eastern brook trout, migratory fish, shorebirds, salt marsh breeding birds, and eelgrass. Robust populations of these species are good indicators of estuarine, marsh, and watershed health. Learn about each of these species below.

Softshell clam beds are primarily found in the Hampton-Seabrook Estuary, although they exist in the Great Bay Estuary, too. Soft shell clams are an important economic, recreational, cultural, and natural resource for the Seacoast region. Recreational shellfishing in the Hampton-Seabrook Estuary is estimated to contribute more than $3 million a year to the New Hampshire economy. Predators (primarily green crabs), disease, and recreational harvest pressures have caused the clam populations to decline. Periodically, harvesting is limited by the presence of red tide toxins and high bacteria counts. For the latest information about clams and shellfish harvest opportunities, check out the Clams Indicator in the State of Our Estuaries report.

Critical Habitats

Habitats that are critical to the health of our estuaries include freshwater wetlands, streams, eelgrass beds, oyster reefs, and salt marshes. These habitats are threatened by increasing population, declining water quality, invasive species encroachment by development and climate change. Learn about each of these species below.

Freshwater wetlands store large quantities of water and provide habitat and food for many wildlife species. They provide a storage basin for rain, snow, and runoff and can be effective at removing pollutants and maintaining clean water. Water from wetlands is slowly released into streams and rivers and helps sustain these systems in periods of low flow and act as sponges in periods of flood protecting people and property. While land protection or local regulations protect some wetland systems from encroaching development, filling, and associated degradation, most wetlands remain vulnerable. Polluted stormwater runoff from developed areas adjacent to wetlands can negatively impact the hydrology, plant community, and habitat value of freshwater wetlands.

Critical Issues

Our estuaries – and their surrounding landscapes – are impacted directly and indirectly by several stressors. Some of these are slow-acting and chronic while others are episodic. These  influences, however, act as stressors and cannot be considered independently of one another. To learn about some of the most significant stressors check out the “Big Picture” section of the State of Our Estuaries report.