Marine ecoregions of the United States

Marine ecoregions of the United States
Name	Marine ecoregions of the United States
Region	United States
Biogeographic realm	Temperate Northern Pacific; Tropical Atlantic; Temperate Northern Atlantic; Arctic
Countries	United States

Contents

Marine ecoregions of the United States are the coastal and offshore marine biogeographic units that frame scientific assessment, conservation planning, and resource management along the United States coastline. Developed from global schemes such as the World Wildlife Fund ecoregions and the Nature Conservancy's seascape classifications, these divisions inform programs by the National Oceanic and Atmospheric Administration, the United States Fish and Wildlife Service, and state agencies including the California Department of Fish and Wildlife and the Florida Fish and Wildlife Conservation Commission. They intersect with international frameworks like the Convention on Biological Diversity and the United Nations Convention on the Law of the Sea.

Overview

The marine ecoregions encompass coastal shelves, estuaries, coral reefs, continental slopes, and Arctic marginal seas that span from the Bering Sea and Chukchi Sea to the Gulf of Mexico and the Caribbean Sea, and from the Atlantic coast of Maine through the Florida Keys to the Channel Islands (California). They are delineated to reflect distinct assemblages of marine fauna such as populations of Atlantic cod, Pacific salmon, and American lobster, and habitats supporting keystone taxa including kelp forests, seagrass meadows, and stony coral communities like those in the Florida Reef Tract and the Flower Garden Banks National Marine Sanctuary. Ecoregions align with management units used by agencies such as the National Marine Fisheries Service and initiatives like the Marine Mammal Protection Act implementation.

Ecoregional classification follows criteria from biogeographers associated with institutions including the Smithsonian Institution, the Scripps Institution of Oceanography, and the Woods Hole Oceanographic Institution, and uses data from programs like the National Centers for Environmental Information and the Integrated Ocean Observing System. Boundaries are often based on oceanographic features—currents such as the Gulf Stream, fronts like the Shelfbreak Front, upwelling zones off Cape Mendocino, and bathymetric breaks along the continental shelf—and on biotic turnover evident in studies by the Monterey Bay Aquarium Research Institute and the Alaska Fisheries Science Center. Jurisdictional overlays include the Exclusive Economic Zone of the United States and state waters governed under the Submerged Lands Act.

The United States contains multiple major ecoregions: the Arctic Alaska region (including the Beaufort Sea and Chukchi Sea), the North Pacific (including the Gulf of Alaska and the Aleutian Islands), the West Coast (from the Salish Sea through Southern California Bight and the California Current system), the Central Pacific (including the Hawaiian Islands and the Papahānaumokuākea Marine National Monument), the Gulf of Mexico and Caribbean (including the Florida Keys National Marine Sanctuary and the Puerto Rico Trench), and the U.S. Atlantic (from the Maine Coast and Georges Bank to the Southeast Shelf and Cape Canaveral). Subregional examples include the Chesapeake Bay, Delaware Bay, Long Island Sound, the Gulf of Alaska fjords, and the Monterey Bay National Marine Sanctuary, each linked to distinct assemblages studied by groups like the New England Aquarium and the Gulf of Mexico Fishery Management Council.

Biodiversity across ecoregions features iconic vertebrates such as humpback whale, gray whale, walrus, sea otter, green sea turtle, and manatee, and invertebrate-rich communities like coral reefs, mangrove stands in Florida Bay and Everglades National Park, and benthic communities dominated by sessile invertebrates on the Northwest Hawaiian Islands. Primary productivity is modulated by upwelling off Oregon Coast and the California Current System, nutrient input from rivers like the Mississippi River, and light regimes tied to seasonality in the Bering Sea and Gulf of Maine. Species of conservation and fisheries importance include Atlantic menhaden, Pacific cod, red snapper, spiny lobster (Panulirus argus), and reef-building corals like Acropora palmata in the Caribbean.

Human pressures—industrial fisheries regulated under councils such as the New England Fishery Management Council and the Pacific Fishery Management Council, offshore energy development represented by projects overseen by the Bureau of Ocean Energy Management, shipping lanes used by the United States Coast Guard, and coastal urbanization in municipalities such as Los Angeles, Miami, and New York City—have altered habitat and species distributions. Climate-driven changes documented by the Intergovernmental Panel on Climate Change and research from the National Climate Assessment include warming, ocean acidification, and sea-level rise affecting coral bleaching events at sites monitored by the NOAA Coral Reef Conservation Program and the Smithsonian Tropical Research Institute. Conservation responses include marine protected areas such as Monterey Bay National Marine Sanctuary, Papahānaumokuākea Marine National Monument, and restoration efforts in Chesapeake Bay guided by the Chesapeake Bay Program.

Management integrates statutes and institutions like the Magnuson-Stevens Fishery Conservation and Management Act, the Endangered Species Act, and interagency coordination among the Environmental Protection Agency, Department of the Interior, and Department of Commerce. Regional governance involves the New England Fishery Management Council, the Gulf of Mexico Fishery Management Council, state coastal management programs authorized under the Coastal Zone Management Act, and cross-border cooperation with entities such as the Organization of American States for Caribbean issues. Policy tools include spatial planning as practiced by the National Ocean Policy and ecosystem-based management promoted by organizations like the Pew Charitable Trusts and the Monterey Bay Aquarium.

Ongoing research is carried out by federal laboratories including the NOAA Pacific Marine Environmental Laboratory and academic centers such as University of Washington, University of California, Santa Barbara, University of Miami, Harvard University's marine programs, and the University of Alaska Fairbanks. Monitoring networks like the NOAA National Marine Fisheries Service surveys, the Integrated Ocean Observing System, and citizen science initiatives run by the Southeast Aquatic Resources Partnership and the Monterey Bay Aquarium Research Institute provide time series for fisheries, ocean chemistry, and biodiversity. International collaborations with the International Union for Conservation of Nature, the PICES research program, and the North Atlantic Treaty Organization science panels support large-scale analyses used to inform adaptive management by entities such as the National Academies of Sciences, Engineering, and Medicine.

Category:Marine ecoregions