EFFECTS OF PULP MILL POLLUTION ON OYSTERS 
167 
The conclusion seems inevitable that the liquor discharged by the pulp mill 
contains substances that affect the normal activity of the gill epithelium and conse- 
quently reduce the rate of feeding of oysters. It must be borne in mind that in the 
experiments just described, the oysters were kept in the solution of red liquor only 
for a brief period of time. It is quite possible that continuous exposure, even in 
very weak concentrations of this toxic substance, which fails to produce any visible 
effect immediately, may cause a general weakness of the organism, reducing its rate 
of metabolism and resulting in its higher mortality. 
III. INVESTIGATIONS OF OYSTER MORTALITY IN OAKLAND BAY, 
WASH. 
By H. C. McMillin 
INTRODUCTION 
The tide lands of lo wer Puget Sound have produced oysters for many generations. 
The springs along the shores were favorite camping sites for the Indians, and the shell 
piles near by bear evidence of the fondness of these people for the Puget Sound oyster. 
For many years after the coming of the white man the Indians continued to harvest 
the crop from the natural beds, but the industry passed to the white man through a 
system of land ownership and sale of rights. 
Oysters were originally found in tide pools of the intertidal zone and on some of 
the low ground. In a few cases shallow channels also supported an abundant crop. 
At the beginning of intensive culture, the tide pools were enlarged or conditions were 
made more favorable for the oysters by removing the mussels and barnacles. 
A new era in oyster culture in Puget Sound dates back to 1890, when the 
late J. Y. Waldrip leveled an area of ground, and constructed around it a dike of 
hand-split cedar boards. The buried ends of the pieces may still be found on Oyster 
Bay, where the original dike contributed to the knowledge of oyster culture. Within 
a short time the success of the new method was apparent. Dikes made of lumber, 
usually an inch thick, held in place by short stakes, appeared in almost every bay in 
the southern end of Puget Sound. Not all of the bottoms upon which dikes were 
built proved suitable for oyster culture, but successful methods of intensive culture 
were worked out in a short time for a large part of the intertidal zone. 
Through several legislative acts the State has granted title to the oyster growers, 
and they now hold the land in fee simple. This has encouraged extensive improve- 
ment, and oyster land in Puget Sound is the most valuable of any oyster bottom in 
the nation, some being worth about $15,000 per acre. 
Conditions in Oakland Bay are favorable to oyster culture. Tidal ranges of 8 
to 18 feet cause strong currents; solid bottoms make easy the construction of per- 
manent dikes; and gravel along the beach furnishes surfacing material. The making 
of new ground has continued slowly as the oystermen have spent their profits on 
leveling, diking, and surfacing. At present about two-thirds of the available ground 
is in shape to produce oysters. Each year the area is increased by new improve- 
ments. The abandoned dikes about the head of Oakland Bay and in Swindel Cove, 
do not represent a reduction of the industry, but are the results of early experimenta- 
tion already discussed, and much of this ground will eventually be improved and 
cultured by modern methods. (Fig. 42.) 
