Estuaries

Habitat code: 512

Photo: KMD
The estuary ecosystem is a place where the influences of the salt water and fresh water meet. Many plants and animals have come to rely on this unique environment. Some spent their entire life cycle within the estuary while others depend on this environment as a stop-over on their migratory paths. For juvenile salmon the estuary and near-shore habitat are critical elements in their survival.

If you'd like a list of some other plants and animals that depend on the estuary...click on.

  • Birds
  • Mammals
  • Sea creatures
  • Fish
  • Insects

    • Below is a representative example of some plants and animals you might find in the estuarine habitat.


    Spartina
    Spartina alterniflora
    Photo: COOP    		 Distribution and Habitat:
    Three species of Spartina (Spartina alterniflora, S. patens, and S. anglica) are invading intertidal areas of Washington, Oregon, California and British Columbia. In Washington, Spartina is present in Willapa Bay and the Puget Sound. Introduced in 1894. It now covers more than 2,000 acres, and is a threat to oyster beds, mud falts, and eelgrass meadows.

    Interesting fact:
    Spartina is a prized aquatic plant in the east coast. It provides shelter and breeding sites for many of their estuarine organisms.


    Pacific Harbor seal
    Phoca vituline
    Photo: KMD    		 Distribution and Habitat:
    It is found in coastal waters, marine estuaries and rivers in areas free from ice.

    Diet:
    It feeds largely on fish such as cod, flatfish, and salmon.

    Interesting fact:
    Pacific harbor seals have been known to live in captivity for well over 30 years. The earless seals, to which the Pacific harbor seal belongs, appeared in the fossil records about 15 million years ago.


    Farmed salmon
    Photo: AG    		 Distribution and Habitat: Salmon are raised commercially in pens on the east and west coast.

    Interesting fact:
    The farmed salmon industry needs clean water with adequate oxygen for the fish to survive and grow efficiently to market size. The Clam Bay site is located in the Rich Passage of Puget Sound, where the powerful tidal currents flush the area several times a day.


    Shucking oysters
    Photo: AP    		 Distribution and Habitat:
    Wherever there are accessible beaches, people can find clams and oysters at low tide.

    Diet:
    Oysters are filter feeders, grabbing nutrients floating in the water. People eat just about anything.

    Interesting fact:
    Shellfish beds can be contaminated by runoff during heavy rains.


    Geoduck clams
    scientific name
    Photo: AP    		 Distribution and Habitat:
    Estuaries and beaches. Geoducks are sessile and do not move once they have selected a site about 2' below the surface of the sand. Native littleneck clams and manillas (introduced from Japan) are much smaller and live just beneath the surface of the beach, and further up the beach in the intertidal zone.

    Diet:
    Geoduck clams, like their smaller clam cousins, are filter feeders. They stick their long necks above ground to feed.

    Interesting fact:
    They are very large. You may find them at fish markets weighing 3 pounds and about 16-18" long. Their name is pronounced GOOEY duck.