2, Effeot of water extract of crude oil : 



A toxic effect on oysters of water soluble fractions of crude oil 

 has been demonstrated in the irwestigations conducted by the Service in 

 Louisiana (Galtsoff et al., 1935). The following experiments, carried 

 . out with samples of crude oil supplied by the TJ« S» Navy, show similar 

 results leing Tubularia * The extract was prepared by adding 200 ml, of 

 oil to 4 liters of unfiltered sea water and shaking the mixture for 

 6 1/^ hours on a mechanical shaking machine. The container was then 

 inverted and 48 hours allowed for the sepeuration of the oil and water* 

 The water extract was withdrawn from the bottom and added to sea water 

 in stiffioient queuitities to give the desired concentrations, which, in 

 •tiie first series of tests, were 1:20, 1:8, 1:4, and 1;2. Jn a second 

 series more dilute solutions were used, the concentrations being 1:40, 

 1:200, 1:400, and 1:1,000, These concentrations would correspond to 

 dilutions of the original crude oil frcm 1:800 to ij20,000. It was 

 expected, of course, that the vigorous shaking of the crude oil with 

 sea water would result in water soluble extractions in greater amount 

 than might be obtained by simply keeping oil in contact with standing 

 sea water* 



All tiie tests were made in finger bowls using 200 ml* of water 

 which was neither agitated nor aerated* The tests lasted 24 hours. 

 No mortality in the control occurred in the first series, while in 

 ■tiie second series only six out of sixty Tubular ia died in the control 

 dish. As one can see from the examination of tables 6 and 7, the 

 extract was toxic in the concentration up to 1:200 (1:2,000 of the 

 original crude oil sample). 



These experiments show that crude oil contains toxio substeuices 

 that can be extracted by shaking with sea water. Under natural con- 

 ditions one may expect that strong agitation of water by wind or the 

 back and forth movement of water over submerged oil would tend to 

 increase the concentration of toxic substances* 



3* Toxicity of various types of oils eind oil and carbonized sand 

 mixtures in running sea wateTl 



In the first set of tests a large container with running sea water 

 served as a common supply from which, by means of a siphon, the water 

 was carried to each of the beakers of 600 ml* capacity containing test 

 materials. From the beakers the water was siphoned to small finger 

 bowls in which the Tubularia were placed. The control was arranged in 

 a similar manner but minus the test material. All the siphons were 

 adjusted to allow a flow of 700 ml* per minute (42 liters per hour). 

 The 600 ml* beakers were kept approximately two-thirds full, and the 

 finger bowls with polyps held 250 ml. In each instance 20 ml* of test 

 oil alone, or oil mixed with carbonized sand, were used. 



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