144 
BULLETIN OF THE BUREAU OF FISHERIES 
FOREWORD 
The mortality of oysters in Louisiana waters in 1932-33, coincident with the 
development of oil wells in the coastal areas of the State, brought up again a question 
as to the possible effect of oil on marine life. In the spring of 1933, at the request of 
the Louisiana Conservation Department, Dr. H. F. Prytherch was detailed by the 
United States Bureau of Fisheries to make an investigation in the Terrebonne Parish 
and adjacent territory with the view of determining the probable cause or causes of 
the mortality. In 1934, in an attempt to carry out a more comprehensive study, 
the Bureau obtained from the Civil Works Administration approval of a project to 
investigate the oil-pollution problem in Louisiana and to carry out both laboratory 
and field experiments in order to determine the effect of oil on oysters. Unfortunately, 
out of the $42,000 allotted for this project only an amount of $3,000 was made avail- 
able, and after the completion of a preliminary hydrographic survey of Timbalier and 
Terrebonne Bays and adjacent bodies of water the field work was discontinued. 
Laboratory experiments on the effect of oil on oysters and oyster food were carried 
out, however, at Beaufort, N. C., Woods Hole, Mass., and Washington, D. C. 
Although the exact cause of the mortality of oysters has not been determined, 
the reports of the field and laboratory investigations throw considerable light on the 
conditions of oyster beds in Louisiana waters and on the possible effect of oil pollu- 
tion on oysters. 
INTRODUCTION 
By P. S. Galtsoff and H. F. Prytherch 
The fact that the discharge of oil into natural waters may be detrimental to aquatic 
life has been recognized for a long time and was a subject of lengthy discussion before 
the numerous governmental committees (Oil Pollution in Navigable Waters, 1926; 
Pollution of Navigable Waters, 1930) attempting to remedy the situation by proper 
legislative action. In view of the widespread oil pollution of coastal waters, espe- 
cially in the vicinity of large cities and industrial centers, and the interest in this 
problem shown by many Federal and State agencies, it is surprising to learn that 
there has been very little direct experimentation on the effect of crude oil or its 
derivatives on fresh-water or marine organisms and that most of the statements 
appearing in the minutes of official hearings are based primarily on field observations 
and frequently represent opinions and assumptions not corroborated by direct 
evidence. 
It is true that in the case of gross pollution conditions in the affected body of 
water may be such as to make any deeper investigation superfluous. However, when 
pollution is light or only temporary, the lack of knowledge of the toxic properties 
of oil and of the manner in which it may affect various organisms, constitutes a serious 
handicap in developing efficient methods of protection. In the case of the location 
of oil fields in the coastal area, the question arises as to whether or not the coastal 
fishery and the oil industry can coexist. The problem is of particular importance 
in south Louisiana waters where the production of oil has increased rapidly from a 
total output of 5,032,400 barrels in 1927 to 15,540,341 barrels in 1933, according to 
Dabney (1934). Drilling operations have been extended to within a few miles of 
the Gulf of Mexico, particularly in Terrebonne Parish, where, according to the 
statistics of the Louisiana Department of Conservation, there were 17 wells in opera- 
