440 
BULLETIN OF THE BUREAU OF FISHERIES 
Pacific coast are produced, in the southern portion of Puget Sound in the vicinity of 
Olympia, Wash. They are sold on the market as Olympia oysters, and a distinction 
is made between them and the same species grown in other localities. 
According to Stafford (1914) the species was described by Carpenter, who gave 
the name, as follows: “Ostrea lurida, n. s. Shape of edulis: texture dull, lurid, olivace- 
ous, with purple stains.” The species is known to occur in bays and estuaries from 
British Columbia to southern California. However, in some respects the oysters are 
quite different both in appearance and marketability with respect to their place of 
origin. Townsend (1893) hardly considered the native oyster of San Francisco Bay 
of commercial significance, although present in large numbers. The same species, 
farther north, at that time was bringing good prices in the markets. This was due in 
part to the difference in climate in the two localities, and in part to the fact that 
growers were beginning to cultivate their grounds and care for their crops systematic- 
ally, instead of merely harvesting the natural supply. 
Because of their susceptibility to the hot sunshine of summer and the freezing 
winds of winter, native oysters in Washington thrived only where they were relatively 
protected. Natural beds were found where the oysters were covered with water at 
low tide because of the slope of the tide land, or where seepage from underground 
would keep them moist in summer and relatively warm in winter. Pot holes would 
contain oysters while the intermediate ground, which becomes completely exposed at 
low tide, would be bare. 
At the end of the last century, a few years after the appearance of Dean’s work 
(1890) describing the method of oyster culture employed in France, the oystermen 
began to build dikes or structures on the tide lands which would keep the beds cov- 
ered at low tide. The dikes are, in principle, closely similar to those described and 
pictured by Dean as the “oyster parks” used in France. Whether or not the French 
system furnished the original inspiration for the mode of oyster culture that was de- 
veloped in Puget Sound within a few years is not known, but owners of natural ground 
began to build dikes around the beds so that the oysters would remain covered with 
water at low tide. 
After a few years of experimentation, during which it was demonstrated that 
dikes make it possible to grow oysters on ground previously unused as well as to reduce 
mortality due to freezing, the entire industry in Puget Sound undertook systematically 
to dike the natural beds and expand to other grounds. Until very recent years most 
of the dikes were built of concrete, set well down into the bottom. The thickness of 
these dikes varies from about 6 inches to nearly 12 inches, depending upon the location. 
Now dikes are usually built of creosoted lumber, which lasts a long time and is more 
readily handled (figs. 1, 2, 3). Also, breaks due to settling are less frequent and more 
simply repaired. Dikes have been constructed on relatively level mud flats and on 
sloping banks. In the latter case the dikes are arranged in terraces, involving a 
great amount of hand labor for leveling. In all cases, when new ground is made, 
the rather soft natural bottom has to be surfaced with gravel to make it hard and firm 
as well as to maintain a relatively constant level in spite of the swift tides. 
In southern Puget Sound, according to the tide tables of the U. S. Coast and 
Geodetic Survey, the maximum range of tide is 20 feet, from —3.8 to +16.2 feet. 
Most of the oyster grounds are between the —1-foot and the +3-foot tide levels, 
though some dikes require a tide as high as +8 feet to cover them. A few natural 
beds are in sloughs or shallow channels where they are never exposed. On the other 
hand, the natural beds of the same species in Yaquina Bay, Oreg., are covered by 
from 10 to 20 feet of water at low tide. In Puget Sound oyster growers have found 
