Of the several oyster1 species found on this coast, only one, the Olympia oyster2 Ostrea lurida (conchaphila3) is indigenous.  It is now rare on most open-coast shores, but may be locally common in embayments. Several other species4 of Ostrea and Crassostrea may be present locally, either released accidently from mariculture facilities or intentionally introduced. Many of these species either don't reproduce or do so only infrequently. An exception is the Japanese (Pacific) oyster Crassostrea gigas, which reproduces frequently and is locally abundant along the entire west coast. Because of the economic interest in oyster culture on the west coast there is an enormous literature on reproductive and larval biology, most of it applied and too voluminous to be included here; however, a few studies are represented.  In contrast to the large volume of mariculture research on oysters, little attention has been paid to their ecology.

NOTE1  the English word “oyster” derives from the Old French “oistre”, and that presumably from the Latin “ostrea”, referring to the animal.  In the absence of an original English common name for oyster, one wonders if they were missing from British diets until after the Norman invasion of 1066.  In this regard,recall the words of Jonathan Swift (Gulliver’s Travels):  “It was a bold person that first ate an oyster”, to which one humorous wag has added:  “but bolder still the first that ate an oyster with the shells removed”!

photograph of oysters Crassostrea gigas and Ostrea conchaphilaNOTE2  the Olympia oyster has recently enjoyed a surge of interest in the dedication of an entire issue number of Journal of Shellfish Research (2009 Vol 28 Issue 1) to its biology.  Several papers from this journal are included in this section of the ODYSSEY

NOTE3  a recent paper on the genetics of Ostrea populations from Baja California to British Columbia confirms that there are, in fact, two separate species, with O. conchaphila being restricted to localities south of central Baja California, and O. lurida to all localities north of this location.  In view of this all future (from 2009) literature references in the ODYSSEY to the northern taxon will be changed to reflect these new designations.  Polson et al. 2009 J Shellf Res 28 (1): 11.

NOTE4  these include the European oyster Ostrea edulis, Suminoe oyster Crassostrea ariakensis, Kumamoto oyster Crassostrea sikamea, and eastern oyster Crassostrea virginica

Oysters Crassostrea gigas (Left) and Ostrea conchaphila (Right) 0.6X

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  map showing current distribution of Olympia oysters Ostrea lurida in southern British ColumbiaAn investigation of 98 beaches in southern British Columbia in summer 2009 reveals the presence of live Olympia oysters Ostrea lurida (conchaphila) at 74 (76%) of them (see map).  On the west side of the Island the species is abundant and sometimes forms dense reefs.  In contrast, in the Strait of Georgia the species is widespread but not so abundant.  The authors conclude that although some populations in southern British Columbia are severely reduced in numbers, others have persisted or become re-established despite over-harvesting and other negative anthropogenic effects.  Stanton et al. 2011 Can Tech Rep Fish & Aquat Sci 2940.
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© 2010 Thomas Carefoot

To learn about west-coast OYSTERS: select a topic from the oyster menu at the top of the page

OR: play the ANIMATION of the snail meeting the OYSTERS

OR, if you want to see other animations: follow the snail on its ODYSSEY by CLICKING on any X-marked invertebrate on the map

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Phylum Mollusca (lit. “soft” or “shellfish” L.)

Class Bivalvia (lit. “two folding doors” L.), referring to the two parts of a clam or scallop shell joined by a flexible hinge

SubClass Pteriomorpha (lit. “wing form” G.), including bivalves that attach by byssus threads or cementation

Order Pterioidea, including oysters (Family Ostreidae), including Ostrea conchaphila, Crassostrea spp.

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