160 
BULLETIN OF THE BUREAU OF FISHERIES 
basis of these principles it would be theoretically possible to predict the effect 
of sulphite liquor on oysters in any other body of water on which a similar mill 
might locate. 
Since sulphite liquor is poisonous to oysters, either killing them or causing them 
to take in less food, it should be totally excluded from tidal areas in which oysters 
are cultured. There is a fundamental difference between the results of dumping 
wastes into a flowing stream on the one hand, and into a tide-controlled bay or estuary, 
on the other. In the former case, the waste matter is diluted and washed away by 
constantly flowing, unpolluted water. In the latter case the liquor becomes mix ed 
with water the movement of which, for the most part, consists in back and forth 
fluctuations. The same water, with relatively minor variations, remains day after 
day. To what extent this would be true depends upon the degree to which the body 
of water in question is inclosed and its total volume, the amount of fresh water 
entering, the difference between the tides, and the consequent actual loss of water. 
Other factors, such as direction and rate of currents with respect to location of oyster 
grounds and source of pollution, would have to be given consideration. 
The extent of the damage to oysters in any such location might be predicted if 
the equilibrium concentration calculated should be as high as the concentrations 
studied in the laboratory. For lower theoretical equilibrium concentrations, however, 
low they might be, it would never be safe to say that no damage would be done, for 
all of the effects observed in the laboratory occurred within the relatively short time 
of one month. The dilution at which toxicity ceases, when long periods of exposure 
are considered, can not be stated. Only complete exclusion of liquor from oyster- 
producing waters can be considered as safe. 
SUMMARY AND CONCLUSIONS 
(1) Sulphite liquor, when added to sea water in concentrations from 0.5 to 10.0 
parts per thousand, is decidedly unfavorable to oysters ( Ostrea lurida). 
(2) In concentrations from 0.67 to 10.0 parts per thousand most of the specimens 
died after being treated for from 2 to 29 days, depending upon the concentration of 
liquor. 
(3) In all concentrations tested (0.5 to 10.0 parts per thousand) for a reasonably 
long period of time the specimens either died, or they remained closed much longer 
daily on the average than did control specimens in presumably uncontaminated 
water. 
(4) When the temperature of the water in the laboratory was sufficiently high, 
in the vicinity of 15° C., the control specimens showed 1 to 3 millimeters of new shell 
growth within 2 to 4 weeks. Specimens in water containing liquor did not show any 
perceptible growth. The mantles of treated oysters remained withdrawn into the 
shell instead of protruding slightly at the edge of the shell where new shell is secreted. 
(5) The effect of sulphite liquor on oysters is not due to acidity, for its potency 
is not disturbed by neutralization with NaOH. 
(6) The chief characteristics of the abnormal oysters in Oakland Bay (namely, 
high mortality rate, poor meats, and lack of shell growth) have been produced either 
directly or indirectly in the laboratory by adding various amounts of sulphite liquor 
to the water. 
(7) Concentrations of from 0.5 to 10.0 parts per thousand only were adequately 
tested in the laboratory, but it is not to be assumed, therefore, that in less concen- 
trated solutions the liquor is harmless to oysters. The solutions tested required only 
about 35 days, at most, to produce the effects described in this report, and higher 
