EFFECTS OF PULP MILL POLLUTION ON OYSTERS 
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1 Abova lowest oyster bearing level. 
In order to obtain a mathematical expression for the relation of the height of the 
beds to the number of adult oysters and percentage of mortality in Oakland Bay, the 
coefficient of correlation was calculated. Samples were taken on a line extending 
from high water to low water directly across the beds. (Table 9.) The results of 
three such series were combined, making a total of 21 stations. Standard methods of 
computations gave a correlation coefficient (“r”) between height and per cent of 
dead oysters of —0.6996 ±0.075, showing that the loss is very closely associated 
with the height of the beds, the largest number of dead oysters being on the low 
ground. Between height of bed and number of living oysters the coefficient of corre- 
lation was 0.5866 ± 0.096, showing that the number of live oysters increased directly 
with the height of the bed. The values thus obtained are relatively high for biological 
data. They are respectively 9 and 6 times their probable error, which shows that the 
correlation is significant. Similar treatment of figures obtained from beds in Totten 
Inlet (Oyster Bay) showed no correlation between the number of dead oysters and 
position of beds from which the sample was taken (r= —0.3316 ±0.226) but a high 
positive correlation between the number of live oysters and position (r = 0.8166 ± 
