EFFECT OF CRUDE OIL POLLUTION ON OYSTERS 
203 
Both in the sea water and in Miquel solution the retarding effect is directly 
proportional to the concentration of brine (fig. 20). 
From the results of the experiments it becomes apparent that brine contains 
substances which interfere with the growth and rate of propagation of the diatom. 
F ?bruary 1934 March 
Figdee 19.— Effect of brine on the growth of Nitzschia in Miquel solution. 
The experimental work reported in this part of the report provides sufficient evi- 
dence of the possible adverse effect of crude oil and bleed water on the food supply of 
oysters and other plankton feeding animals of the sea. Probably the retarding 
effect of crude oil on the rate of diatom growth is primarily due to the toxic action of 
its water-soluble constituents. The extraction of this substance or substances is 
undoubtedly facilitated by the action of wind and current. Oil absorbed by mud 
