The Hampton-Seabrook Estuary is a vast ecological system composed of salt marsh, sand dunes, beaches, tidal waters, and brackish streams. The estuary is a pivotal connector that provides habitat continuity between the Gulf of Maine to the north and the Great Marsh to the south in Massachusetts.

As such, it supports critical roosting, feeding, and nesting grounds for shorebirds. and It also provides critical nesting habitat for salt marsh sparrows, a species designated as Endangered by the International Union for Conservation of Nature. The towns of Hampton, Hampton Falls, and Seabrook depend on the estuary for tourism, commercial and recreational fishing, recreational shellfishing, aquaculture, and critical ecosystem services such as flood protection and carbon sequestration.