188 
BULLETIN OF THE BUREAU OF FISHERIES 
This observation has an important bearing on the problem of oil pollution of 
natural waters, indicating that oil floating on water or absorbed in mud will, for a 
long time, remain a source from which toxic substances diffuse into the water. It 
seems probable that the toxic effect is not due to the mineral salts which occur in 
the crude oil and which doubtless will be leached out by subsequent washings, but to 
the organic compounds which gradually dissolve in the sea water. 
Table 17. — The effect of oil well bleed water on the rate of 'pumping of water by the gills of the oyster 
[Drop counting method] 
Experiment 
no. 
Date 
Drops per minute 
Effect 
of 
treat- 
ment 
Bleed 
water 
on — 
Per- 
cent 
bleed 
water 
No 
cur- 
rent 
for— 
Specific gravity 
17.5/17.5 
Temperature, 
“0. 
pH 
bleed 
water 
solu- 
tion 
Source 
bleed 
water 
Before 
treat- 
ment 
Dur- 
ing 
treat- 
ment 
After 
treat- 
ment 
Sea 
water 
Bleed 
water 
Begin- 
ning 
End 
Min. 
Min. 
55 
Nov. 24 
61.0 
58.2 
65.7 
95 
10 
10 
1.0258 
1.0261 
15.5 
15.8 
7.3 
Barre. 
63 
Dec. 4 
125.8 
113.0 
108.7 
90 
5 
10 
1. 0262 
1. 0267 
17.3 
17.0 
Do. 
C3B 
41.2 
30.3 
40.0 
73 
5 
10 
1. 0260 
1. 0265 
15.2 
15.6 
Do. 
64 
__do 
66.0 
73.0 
80.7 
111 
5 
10 
1. 0260 
1. 0264 
16.2 
16.6 
Do. 
65 C 
Dec. 8 
80.7 
95.6 
87.3 
106 
10 
10 
1. 0268 
1. 0263 
14.8 
15.2 
7.5 
Pelto. 
Average. 
95 
54 
Nov. 23 
78.7 
57.5 
69.0 
73 
10 
20 
1. 0255 
1. 0259 
16.4 
16.6 
7.3 
Barre. 
64 B 
Dec. 6 
77.5 
80.2 
82.5 
103 
5 
20 
1. 0260 
1. 0257 
16.2 
16.6 
Do. 
64C . 
95.0 
74.8 
96.3 
79 
10 
20 
1. 0260 
1. 0258 
17. 1 
17.3 
Do. 
C5D_ 
Dec. 8 
97.0 
89.6 
91.6 
91 
10 
20 

1. 0268 
1. 0268 
15.2 
15.2 
Pelto. 
Average. 
86.5 
65 
Dec. 7 
74.2 
70.2 
89.0 
94 
10 
33 
1. 0268 
1. 0302 
15.0 
15.0 
7.3 
Barre. 
65 B 
Dec. 8 
86.2 
35.0 
100.5 
41 
10 
40 
3 
1. 0268 
1. 0397 
14.1 
14.4 
7.3 
Do. 
53 
Nov. 21 
71.2 
55.0 
68.0 
77 
10 
33 
1. 02535 
1. 0379 
12.8 
13.2 
7.3 
Do. 
53A 
97.0 
70.7 
96.0 
81 
10 
33 
1. 02535 
1. 0379 
15.9 
Do. 
53B 
Nov. 22 
130.0 
56.5 
97.4 
44 
10 
40 
1. 02559 
1. 0436 
16.6 
7.7 
Do. 
Average. 
67. 4 
67A 
Dec. 11 
57.0 
16.0 
36.0 
28 
14 
50 
10 
1. 0267 
1. 0532 
14. 1 
14.3 
Barre. 
68A 
Dec. 12 
71.0 
10.0 
32.0 
14 
10 
60 
12 
1. 0267 
1.0638 
11.6 
11.7 
Do. 
68B 
Dec. 13 
91.0 
21.5 
18.0 
24 
10 
80 
29 
1. 0267 
1. 0851 
12.0 
12.0 
7.5 
Do. 
69 A 
Dee. 15 
84.0 
4.5 
24.5 
5 
10 
100 
120 
1. 0267 
1. 1064 
14.4 
15.4 
7.5 
Do. 
EFFECT OF BLEED WATER ON THE RATE OF FEEDING 
Eighteen experiments were made with “bleed water” or brine from the Barre 
and Pelto wells during November and December 1933, using the drop counting 
technique. An adjustment period of from 10 to 30 minutes preceded the beginning 
of the measurements. A summary of all the experiments is given in table 17. Column 
3, “Before treatment,” shows the rate of pumping in drops per minute, averaged by 
5-minute intervals, from the time the kymograph was started until the test solution 
was turned on. The elapsed time for this period is usually 20 minutes. 
Column 4, “During treatment”, shows the average rate of flow in drops per 
minute while the test solution was flowing over the oyster, and for 10 minutes after 
the test solution was turned off, as this time is required to replace it with sea water. 
The test solution was on for 5 or 10 minutes in most cases (col. 7). 
Column 5, “After treatment”, shows the average rate of pumping in drops per 
minute for a period about 20 minutes immediately after treatment. The value is a 
measure of recovery occurring during this period. There was not always a sufficient 
time for the rate of flow to return to the level established before treatment, but a 
