Olympia Oyster

The Science

The Olympia oyster is the only oyster that is native to the west coast of North America.

The Fishery

During World War II, the U.S. military contracted with Washington oyster growers to provide oyster meats as source of nutritious protein for soldiers.

The Seafood

Olympia oyster was very popular in the 1800s during the Gold Rush. Mark Twain loved them so much he put them on his “fantasy menu” along with his other favorite foods.

The Science

Olympia Oyster
ittibittium/CC BY-NC

Taxonomic description

  • A marine bivalve mollusk, in the marine invertebrate group along with other oysters
  • Often reaches 6-8 cm (2.4-3.1 inches) length and 2.5-3.5 cm (0.90-1.3 inches) thick [1]
  • Shell shape variable, often forming to the shape of the surface on which it grew[1]

Distribution

  • Found on the west coast of North America, from southern Alaska to Baja California, Mexico [1,2,3]

Life history

  • Spawning is triggered by water temperature of 16-18C (60-64F) and can occur 1-2 times per year between spring and fall [1].
  • Broods; fertilized eggs develop in the female mantle [1]
  • An average brood of larvae is between 250,000-300,000
  • Maximum age is unknown

Habitat

  • Lives in estuaries, sounds, tidal channels, and bays.
  • Filter feeder, eats microscopic algae and plankton [3]
  • Many predators including birds, rays, and rock crabs.
  • Sensitive to water temperature changes, but can tolerate short exposure to changes in salinity [1]
  • Large amount of its natural habitat has been removed to due urban development and pollution [2]

The Fishery

olympia_oyster_fishing
The Nature Conservancy, Youtube

Seasonal availability

  • Shellfish farms often provide year round availability.

Managing authority

  • Farmed with strict governing by Federal Agencies: NOAA, Army Corps of Engineers, Fish and Wildlife Service, USDA, EPA, FDA, BOEM, and the Coast Guard [11]
  • In states where recreational shellfishing is common, the state Department of Fish and Game regulate seasonal harvest [5]
  • In Washington state, the minimum size for oyster harvest is 2.5 inches.  The large minimum size is thought to prevent much collection of the oyster [5]

Gear type

  • Oyster farming in the U.S. began in 1890s in Puget Sound tidelands [6]
  • Oysters are grown by on-bottom, off-bottom or suspended culture methods [11]
  • The standard marketable size of an Olympia oyster is about the size of a silver dollar (3.5-4 cm) [6]

Status of the fishery

  • Native American harvested Olympia oysters for food [6]
  • Production peaked from 1890s to 1900 but greatly declined after due to pollution and over harvesting [6]
  • Larger, faster growing species, like the Pacific Oyster from Japan, continue to dominate oyster farming in the U.S. [7]
  • It takes 3-5 years for an Olympia oyster to reach market size [6,7]
  • A growing interested in the local food movement has increased interest in the Olympia oyster [10]

Potential ecosystem impacts

  • Oyster farms have minimal impacts to local ecosystems. [9]
  • Oyster beds provide many ecosystem benefits such as: habitat for other species, improved water quality, biodiversity support, reduced shoreline erosion, and enhanced restoration projects [8]
  • Monterey Bay Aquarium’s Seafood Watch classifies farmed oysters as three of its “Best Choices” for seafood options [9]

The Seafood

Washington State Department of Agriculture/CC BY-NC 2.0

Edible portions

  • Everything but the shell is edible and is typically prepared
  • Oyster shells should always be tightly closed prior to preparation [12]

Description of meat

  • Olympia oysters have a bright, earthy, coppery taste [13]; sometimes described as peppery

Culinary uses

  • Local Olympia oyster is often available fresh from the farm.
  • Shucking the shell is manageable. Instructions can be found in multiple online resources  (e.g., [15])
  • Olympia oysters can prepared many ways: Freshly on the half shell, fried, steamed, smoked, in soups and stew, and more [13]

Nutritional information  

  • Low calorie, easier to digest than red meat, and high in vitamins [14]
  • Raw Pacific oyster (50g or 1.8oz) [16]

References

[1] Couch, D. and T.J. Hassler. 1989. Species profiles: life histories and environmental requirements of costal fishes and invertebrates (Pacific Northwest) —Olympia oyster.  U.S. Fish Wild. Serv. Biol. Rep. 82(11.124) U.S.Army Corps of Engineers, TR EL_82-4. 8pp.

[2]Timmins-Schiffman E, Friedman C, Metzger D, White S, Roberts S. Genomic resource development for shellfish of conservation concern. Molecular Ecology Resources [serial online]. March 2013;13(2):295-305. Available from: Academic Search Complete, Ipswich, MA. Accessed May 13, 2014.

[3]http://www.habitat.noaa.gov/restoration/techniques/oysters.html

[4]"http://w3.shorecrest.org/~Lisa_Peck/MarineBio/syllabus/ch7invertebrates/..."http://w3.shorecrest.org/~Lisa_Peck/MarineBio/syllabus/ch7invertebrates/...

[5] Washington Dept. Fish & Wildlife. http://wdfw.wa.gov/fishing/shellfish/ps_clam_oyster_faqs.html

[6] Couch, D. and T.J. Hassler. 1989. Species profiles: life histories and environmental requirements of costal fishes and invertebrates (Pacific Northwest) —Olympia oyster.  U.S. Fish Wild. Serv. Biol. Rep. 82(11.124) U.S.Army Corps of Engineers, TR EL_82-4. 8pp.

[7] Beahrs, A. (2012). Heaven on the Half Shell. Smithsonian, 43(3), 62-69.

[8] NOAA - Oyster Restoration - http://www.habitat.noaa.gov/restoration/techniques/oysterrestoration.html

[9] Seafood Watch 2014  HYPERLINK "http://www.seafoodwatch.org/cr/seafoodwatch/web/sfw_factsheet.aspx?fid=82"http://www.seafoodwatch.org/cr/seafoodwatch/web/sfw_factsheet.aspx?fid=82

[10] Sunset Magazine.  Christopher Hall, The West Native Oyster Makes a Comeback.  HYPERLINK "http://www.sunset.com/travel/northwest/olympia-oyster"http://www.sunset.com/travel/northwest/olympia-oyster

[11] FISHWATCH. U.S. Seafood Facts. NOAA.  HYPERLINK "http://www.fishwatch.gov/seafood_profiles/species/oyster/species_pages/p..."http://www.fishwatch.gov/seafood_profiles/species/oyster/species_pages/p...

[12]  Pacific Coast Shellfish Growers Association- PCSGA. http://pcsga.org/buying-tips/

[13] Taylor Shellfish Farms. http://www.taylorshellfishfarms.com/about-our-shellfish.aspx

[14] Sea Grant Washington. http://www.wsg.washington.edu/oysterstew/news/nutritious.html

[15] Localfoods. How to Shuck Oysters.  HYPERLINK "http://localfoods.about.com/od/shellfishrecipes/ss/How-To-Shuck-Oysters.htm"http://localfoods.about.com/od/shellfishrecipes/ss/How-To-Shuck-Oysters.htm

[16] Seafood Health Facts. Pacific Oyster, 2013. < HYPERLINK "http://seafoodhealthfacts.org/seafood_choices/oysters.php"http://seafoodhealthfacts.org/seafood_choices/oysters.php>.