graphic of heron and crab in water
Estuary artwork produced by D. Caldwell for the National Park Service
Estuaries and their surrounding wetlands are found where rivers meet the sea. They are home to unique plant and animal communities that have adapted to brackish water—a mixture of salty seawater and fresh water draining from the land. Estuaries are among the most productive ecosystems in the world and many animals rely on the habitat provided for food, places to breed, and migration stopovers.

There are National Natural Landmarks designated for their estuaries nationwide that illustrate the beauty and diversity of these ecosystems. Some of these include:

Mobile-Tensaw River Bottomlands, AL
Año Nuevo Point and Island, CA
Lanphere and Ma-le'l Dunes, CA
Nipomo Dunes-Sal Costal Area, CA
Point Lobos State Reserve, CA
Tijuana River Estuary, CA
North and South Rivers, MA
Puerto Mosquito, PR
St. Phillips Island, SC
Virginia Coast Reserve, VA
Salt River Bay, VI
Nisqually Delta, WA

Last updated: August 1, 2022


  • Site Index