Washington's Coast
Washington State Department of Ecology

dune plants
Spartina in Willapa Bay
Spartina in Willapa Bay Nearly a third of Willapa Bay's 45,000 acres of tide flats are infested with Spartina, an invasive salt marsh grass.
Shorebirds feeding on tide flats, Bowerman Basin, Grays Harbor Open tide flats, without Spartina, are essential for the survival of shorebirds, salmon, and shellfish.

Spartina is rapidly invading Willapa Bay
Rapid Spartina growth in Willapa Bay

  • In 1982, there were 400 acres of Spartina and 44,600 acres of tide flats in Willapa Bay.
  • By 2047, 30,000 acres of Spartina could dominate Willapa Bay, leaving only 15,000 acres of tide flats.
Taking over tideflats
  • Spartina is crowding out habitat for shellfish, birds, juvenile fish, and other wildlife.
  • Spartina spreads quickly. The growth rate is about 17% per year.
  • Spartina has taken over 15,000 acres of tidelands in Willapa Bay. Seedlings occupy another 6,500 acres.
  • Spartina is also found in the Copalis River estuary and at Damon Point in Grays Harbor.
How spartina harms the shore
  • Fish and shellfish lose habitat
    Spartina converts mud flats into marshes. More marsh means less rearing habitat for juvenile salmon, clams, and oysters. The loss of tide flats threatens the $16 million oyster industry in Willapa Bay.
  • Birds lose habitat
    In the Willapa National Wildlife Refuge, Spartina has displaced 16 to 20 percent of the key habitat for wintering and breeding birds.
  • Flooding risks increase
    Spartina can clog estuaries and increase the risk of flooding. Infested areas fill in, restricting water flow. Waterways become steep-sided, narrow channels.
  • Recreational access is lost
    Spartina can close off waterfront property, decrease boating access, and turn beaches into marshy barriers.
How did Spartina arrive?
Spartina alterniflora is a deep-rooted salt marsh species native to the Atlantic and Gulf coasts. Spartina was introduced into Willapa Bay in 1894 as packing material for oyster shipments from the East Coast. Spartina began growing on the west side of Long Island, but was not identified until the 1940s. From 1945 to 1988, the plant spread rapidly throughout Willapa Bay.
Controlling Spartina
  • Catch it early
    The best way to control Spartina is to catch it early, before infestations become established.
  • Hand pulling and digging
    Individual seedlings or small clumps can be controlled by hand pulling or digging during the summer. The plants must be disposed of away from the intertidal zone, to prevent the spread of seeds or rhizomes.
  • Other removal methods
    The Washington State Department of Agriculture (WSDA) is coordinating Spartina control efforts along Washington's coast in counties with known infestations. Control techniques used include a combination of mowing, digging, hand pulling, and chemical treatments.
  • Getting help
    If Spartina is on your beach, or you want to remove it, contact: the WSDA Spartina Program, PO Box 42560, Olympia, Washington. Phone: (360) 902-1853 or (360) 902-1923.

Spartina information
The Washington State Department of Agriculture (WSDA) is the lead state agency for the eradication of Spartina. For more information, you can email them (PestProgram@agr.wa.gov) or call (360) 902-2070.

Spartina alterniflora

How Spartina spreads

  • Spartina grows from seeds or root pieces. Shoots sprout from rhizomes during the spring. The plants reach 3 to 6 feet by mid-summer.
  • Spartina is spread when water, humans, or animals move the seeds, rhizomes, or plants.
  • Spartina flowers from late June to October.
  • Spartina alterniflora is a beneficial plant in its native range along the Atlantic and Gulf coasts.
Images courtesy of: The Western Aquatic Plant Management Society

Washington State Noxious Weed Control Board, Spartina Alterniflora. How to identify Spartina Alterniflora. Spartina is classified as a noxious weed.

Puget Sound Partnership Resource Center, Spartina cordgrass. Information on four species of non-native Spartina that have made their way into the Puget Sound.

U.S. Fish and Wildlife Service, Willapa National Wildlife Refuge, Spartina Control. How the refuge and a variety of partners have worked together to control Spartina.

Washington State Department of Agriculture, Spartina Eradication Report

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