EFFECT OF CRUDE OIL POLLUTION ON OYSTERS 
159 
immersion in a fuel oil extract. Gardiner (1927) found that the aqueous extracts of 
tar were completely without effect on freshly fertilized eggs and on “eyed” ova of 
trout, and that the resistance of trout alevins to the toxic action of phenol decreased 
with age. Alevins 60-66 days old were quite unaffected by 2-hour immersion in a 
solution of 40/100,000 phenol, whilst fry 110-115 days old were unable to withstand 
more than 15 minutes immersion. 
Elmhirst (1922) found that oil in water had no effect on a number of bottom 
organisms (Purpurea, Serpula, Authozoa, Ascidia, Mollusca) and many planktonic 
forms although the latter were lulled when they came in direct contact with oil. 
According to James (1926), under conditions approaching those prevailing in nature, 
a 0.1 percent dilution of light or heavy bunker oil exerts no effect on the development 
of cod eggs, but toxic effect of the same oils becomes apparent under conditions of 
limited circulation and aeration. Slight injurious effect is exerted by the same oils 
upon larval flounders. He rightly states that further research should be based upon 
more specific knowledge of the physical and chemical phenomena accompanying oil 
pollution. 
Considerable discrepancies in the results of the experiments mentioned in this 
brief revue may be attributed to various causes, namely, differences in the chemical 
composition of oils used, defects in experimental technique and small number of 
observations. It has been the purpose of the present experiments to obtain a better 
understanding of the effect of oil and brine on oysters and to carry them on a more 
comprehensive scale than has been done before. The experimental investigation 
comprises two distinct parts ; a study of the effect of oil and bleed water on mortality, 
rate of feeding and behavior of the adductor muscle of the oyster; and a study of 
the effect of oil on the growth of a diatom. For the latter experiments the culture 
of a single species of Nitzchia clostearia E. was used. It is believed that the results 
obtained with this planktonic species which occurs in the normal habitat of the oyster, 
are applicable to other planktonic diatoms. 
Most of the experiments on oysters were carried out at the United States Fisheries 
laboratory at Beaufort, N. C. Studies on diatom growth were made at the Bureau 
of Fisheries laboratory in Washington and Woods Hole, Mass. Since the experi- 
ments carried out by the authors were performed at different times and under differ- 
ent conditions, the results of their investigations are presented separately under 
their respective names. 
SURVIVAL OF OYSTERS IN OIL-POLLUTED WATER 
By Herbert F. Prythercii 
The plan and purpose of these experiments was to expose oysters to high con- 
centrations of the principal polluting substances from the oil wells in order to 
determine their effect on growth and survival. The oysters were subjected to 
crude petroleum, sludge, brine-effluent water, and hydrogen sulphide, samples of 
which, with the exception of H 2 S, were collected previously at the wells by the 
author and stored in glass containers. These studies were conducted at the United 
States Fisheries Biological Station at Beaufort, N. C., and involved the use of several 
