The Rise And Decline Of The Olympia Oyster 



was doubled and the State Reserves in Oakland Bay, 

 which had started a comeback, were again wiped out. 



Oystermen in adjacent bays began to experience 

 heavy mortalities in the lower dike levels and even the 

 clams began to come up out of the ground and die on the 

 beaches. 



In 1949, the State Fisheries Department published 

 Bulletin 49-A which contained data on a study conducted 

 by State Shellfish Biologists over a period of two years 

 on the effects of sulphite waste liquor on Olympia Oys- 

 ters. The summary of their findings is presented below: 



"1. During the period of 1927-1945 an unusual decline 

 occurred in the Olympia oyster fishery of southern 

 Puget Sound. There were years in which young oysters 

 failed to set in areas where a regular spatfall had pre- 

 viously been the rule. Gallons of meats obtained per sack 

 of unshucked oysters decreased during this period by 

 25 per cent. The mortality of mature oysters increased 

 from 10 to 20 per cent (normal) to 30 to 50 percent and 

 higher. Finally, the over-all production of the industry 

 fell to 43 per cent of its previous value. 



2. A number of possible causes of this decline were 

 investigated and found to be inadequate to explain any 

 but a small fraction of this alarming decrease. Sulphite 

 pulp mill waste alone appeared to offer a sufficient cause. 



3. Accordingly an experiment was performed to test 

 the lethal effect over a long period of time of very low 

 concentrations of from 13.0 to 128.9 parts per million of S. 

 W. L. in flowing sea water for 575 days. In that time mor- 

 talities range from 98 per cent in the highest concentra- 



(124) 



