Coasts of the United States

Coasts of the United States
Name	Coasts of the United States
Location	United States

Coasts of the United States are the maritime margins of the United States where continental land meets the waters of the Atlantic Ocean, Pacific Ocean, Gulf of Mexico, Arctic Ocean and associated seas and sounds; they include a mosaic of peninsulas, bays, estuaries, barrier islands, and rocky headlands that have shaped the development of Boston, New York City, Miami, Los Angeles, and Seattle. These shorelines have been the stage for exploration by Christopher Columbus, port growth tied to the Mayflower Compact landing at Plymouth, Massachusetts, naval engagements like the Battle of New Orleans and Battle of Midway, and commerce across routes linked to Panama Canal traffic, the Mississippi River Delta, and the Bering Sea fisheries.

Geography and Extent

The continental and insular margins span from the Arctic coasts of Alaska along the Bering Strait past the Aleutian chain to the Pacific frontage of California, Oregon, and Washington and around the Hawaiian Islands; eastward the shoreline continues along the Gulf of Alaska, the Gulf of Mexico coasts of Texas, Louisiana, Florida, and the Atlantic seaboard through Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, New Jersey, New York (state), Connecticut, Rhode Island, Massachusetts, New Hampshire, Maine, and into the Canadian provinces of New Brunswick and Nova Scotia. U.S. insular coasts include territories such as Puerto Rico, the U.S. Virgin Islands, American Samoa, and the Northern Mariana Islands, while strategic maritime zones are defined by instruments like the United Nations Convention on the Law of the Sea as implemented via agencies such as the National Oceanic and Atmospheric Administration and the United States Coast Guard.

Physical Characteristics and Coastal Types

Coastal geomorphology varies from the rocky headlands of Morro Bay and Point Reyes to the sandy barrier islands of Outer Banks, Assateague Island, and Barrier Islands National Seashore, estuaries such as the Chesapeake Bay and San Francisco Bay, tidal marshes of Louisiana Wetlands and Everglades National Park, and the fjords and glacial shorelines of Alaskan fjords and Glacier Bay National Park and Preserve. Substrate, wave climate, longshore transport and sea-floor topography govern features exemplified at Cape Cod, Long Island, Santa Barbara Channel, Columbia River Bar, and the Delaware Bay entrance; tectonic settings evident at the San Andreas Fault and Cascadia subduction zone produce uplifted coasts and seismic tsunami risk similar to patterns recorded in the 1906 San Francisco earthquake and 1700 Cascadia earthquake.

Ecology and Biodiversity

Coastal ecosystems host habitats such as salt marshes, mangrove swamps in Florida Everglades National Park, seagrass meadows in the Gulf of Mexico, kelp forests off California, and coral reefs around Florida Keys National Marine Sanctuary and Papahānaumokuākea Marine National Monument in Hawaii. These areas support species ranging from commercially important stocks like Atlantic cod, Alaska pollock, blue crab, and pink shrimp to apex predators and migratory fauna including gray whale, humpback whale, North Atlantic right whale, California sea lion, polar bear in Alaska, and seabirds such as brown pelican, piping plover, and Atlantic puffin. Estuarine nutrient cycles and primary production are influenced by freshwater inputs from rivers like the Mississippi River, Columbia River, Hudson River, and Potomac River, while invasive species documented at Ballast water sites and by Asian carp incursions alter community composition.

Human Use and Settlement

Harbors, ports, and coastal cities such as New York City, Los Angeles, San Francisco, New Orleans, Baltimore, Savannah, Georgia, Houston, Galveston, Providence, Rhode Island, and Honolulu have grown around maritime trade, shipbuilding at sites like Bath Iron Works and Newport News Shipbuilding, and fisheries landing sites such as Kodiak and Galveston Bay. Tourism and recreation cluster at destinations including Myrtle Beach, Cape Cod National Seashore, Miami Beach, Santa Monica Pier, and Waikiki, while energy infrastructure spans offshore oil platforms in the Gulf of Mexico, wind projects like those planned near Block Island Wind Farm and Coastal Virginia Offshore Wind, and ports handling commodities under agencies such as the United States Army Corps of Engineers and the Federal Aviation Administration-linked logistics networks. Indigenous coastal cultural sites associated with Navajo Nation trade routes, Tlingit and Haida maritime traditions, and archaeological holdings at Clovis sites reflect long-standing human-environment interactions.

Coastal Hazards and Climate Change Impacts

Shorelines face hazards including storm surge from hurricanes like Hurricane Katrina, Hurricane Sandy, and Hurricane Maria; tsunami threats tied to events such as the 1964 Alaska earthquake; erosion at locales like Cape Hatteras National Seashore; and subsidence in the Mississippi Delta exacerbated by levee systems tied to New Orleans levee failures. Sea level rise documented by Intergovernmental Panel on Climate Change assessments, warming-driven shifts observed by National Aeronautics and Space Administration monitoring, and ocean acidification affecting coral reef bleaching stress coastal economies and habitats. Responses to hazards intersect with insurance and finance instruments in arenas like Federal Emergency Management Agency programs and urban planning responses in cities such as Miami Beach, San Francisco Bay Area, and Norfolk, Virginia.

Management, Conservation, and Policy

Management frameworks involve federal and state entities including the National Park Service, Bureau of Ocean Energy Management, Environmental Protection Agency, National Oceanic and Atmospheric Administration, and state departments such as the California Department of Fish and Wildlife and Florida Fish and Wildlife Conservation Commission, along with non-governmental organizations like The Nature Conservancy, Audubon Society, World Wildlife Fund USA, and Surfrider Foundation. Tools for conservation and regulation encompass marine protected areas like Monterey Bay National Marine Sanctuary, Florida Keys National Marine Sanctuary, Papahānaumokuākea, coastal zone management under the Coastal Zone Management Act, wetlands protection via provisions analogous to Clean Water Act programs, and restoration projects exemplified by Coastal Wetlands Planning, Protection and Restoration Act initiatives in the Louisiana delta. Collaborative science and policy efforts involve research institutions such as Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, Lamont–Doherty Earth Observatory, University of Miami Rosenstiel School, and international engagements through United Nations Framework Convention on Climate Change venues.

Category:Geography of the United States