164 
BULLETIN OF THE BUREAU OF FISHERIES 
i 
analysis at the beginning of the experiment. The experiments were conducted in a 
specially constructed wood tank having 4 compartments of equal size in each of which 
50 oysters were placed. Each compartment had a capacity of 135 liters and, by means 
of an automatic siphon arrangement similar to that shown in figure 7, received an 
equal amount of sea water, which was completely renewed every 3 hours during the 
course of the experiment. One compartment was used as a control and the other 3 
covered with a heavy layer of crude petroleum (2 liters each) of the following grades: 
Barre oil, grade B; Barre oil, grade A; and Pelto oil composite sample. The oil 
completely covered the surface of the 3 experimental tanks and during each low-water 
interval was approximately one-half inch above the oysters. At the end of each week 
10 oysters were taken from each compartment and analyzed for glycogen content by 
P. S. Galtsoff. 
The results of this experiment, given in the following table, indicate a slight de- 
crease in the glycogen content of oysters kept in oil-polluted water. 
Table 4. — Effect of heavy surface layer of oil on glycogen content of oysters 
[Experiment G 1] 
Percent glycogen, fresh basis 
Dec. 6 
Dec. 13 
Dec. 20 
Dec. 28 
Jan. 4 
Average 
1.72 
2.81 
2.68 
2. 67 
1.62 
2. 30 
(1.72) 
(1.72) 
(1.72) 
1.89 
1.82 
2. 56 
2. 54 
2. 10 
1.62 
1. 57 
1.98 
2. 22 
1.82 
1.69 
1.42 
2.29 
1.80 
EXPERIMENTS WITH BRINE 
The principal effluent from the oil wells in Lake Barre and Lake Pelto is the brine 
water that is separated from the petroleum. The quantity discharged daily, at the 
time of the oyster mortality, varied from approximately 5,000 to 7,000 barrels for the 
Barre wells and from 650 to 750 barrels for the Pelto wells. The composition of pe- 
troleum brines, according to Clark (1924), has been found in manj^ instances to be 
quite similar to that of ocean water although modified by local conditions and differ- 
ing in concentration. Such waters have been variously interpreted, sometimes as 
fossil sea water which was entrapped in the original sediments, and sometimes as 
derived by leaching from beds of salt. 
Analyses of the brines from the Barre and Pelto wells are given in table 5, together 
with those of 3 samples of sea water which were collected from the following localities: 
(1) Ctyster bed of St. Pierre, west of Barre walls, where a high mortality of oysters 
occurred, (2) oyster bed at Sea Breeze where no mortality occurred, and (3) Gulf of 
Mexico in ship channel at Buoy No. 3. These analyses, prepared by the Port Arthur 
laboratory of the Texas Co., show that the brines are quite similar to the sea water 
found in this region in respect to the presence and relative amounts of the different 
salts but differ as to their concentration. The samples of Barre brine that were used 
in the subsequent experiments showed a salt concentration of from 122.8 to 123.5 
parts per thousand, while those from the Pelto wells varied from 97.0 to 98.5 parts per 
thousand. The salt content of the water over the oyster beds is considerably lower 
and was found, during the field survey in May 1933, to vary from 15.41 to 22.77 parts 
per thousand, with an average of 18.69. 
