60 U. S. BUREAU OF FISHERIES 
mission to advise on immediate problems and assist in forming a 
general policy of control of the natural beds. 
During the year it has been demonstrated that the location of the 
Pensacola Laboratory, on Santa Rosa Sound, is most satisfactory for 
its purposes. The water was almost always clear and the salinity 
varied from about 20 to about 27 parts per thousand in ordinary 
weather to as low as 12 to 15 parts per thousand during 2 short 
periods of extreme spring freshets. The water temperature through- 
out the year followed closely that of the air, and averaged in mid- 
summer about 74° F., in mid-winter about 60° F. Oysters, fish, and 
other organisms have thrived well in the laboratory aquarium. 
With the assistance of relief funds from the Works Progress Ad- 
ministration and the Public Works Administration a program of 
development of the station was undertaken at the end of the summer. 
It is expected that early in 1939 the Pensacola station will be adapted 
to any type of fishery research. 
Effect of pulp-mill pollution on oysters.—Investigations carried 
out by the Bureau between 1935 and 1937 at the Yorktown Labora- 
tory have clearly indicated that pollution of the river by pulp-mill 
wastes has been responsible for the decline of oyster production. 
During 1938, Dr. Walter A. Chipman, Dr. H. N. Calderwood, R. O. 
Smith, and Lloyd R. Garriss have attacked the problem of determin- 
ing what chemical or chemicals present in the pulp-mill effluents are 
the cause of the altered physiology of oysters. The investigators 
will later attempt to develop a means of eliminating such harmful 
substances. 
The work has been continued on a cooperative basis with the Vir- 
ginia Commission of Fisheries, which contributed $5,000, and with 
the cooperation of the College of William and Mary which granted 
the use of the chemical laboratory and office space in the college build- 
ing at Williamsburg. In addition to the work in Virginia, special 
phases of the York River pollution problem were investigated in the 
Washington Laboratory by Dr. Galtsoff, with the assistance of Doro- 
thy B. Hamilton. These were the abnormal shell structure and other 
pathological conditions found in oysters from the polluted areas of 
the York River. 
In testing the effectiveness of puip-miil wastes in reducing the 
amount of water pumped by oysters, it has been observed that only 
one of the various effluents entering the York River from the pulp 
and paper mill at West Point has a marked physiological action— 
that arising from the pulping process. This mill has three main 
sewer ditches; one draining a sludge deposit, one receiving wastes 
from the paper mill and causticizing section, and one carrying the 
wash waters from the diffuser and the digester building and 
evaporators. 
Frequent sampling of the discharges from the sewers has revealed 
wide and irregular fluctuations in the character and physiological 
activity of the effluents. However, these effluents have been grouped 
under three main categories for the purpose of study; crude sulphate 
soap, foam from the mill sewer outlets, and weak black liquor. 
At times considerable quantities of crude sulphate soap find their 
way into the effluents, being washed in from the ground surrounding 
the black liquor storage tanks. ‘These soaps have a marked physi- 
ua 
