situations, the cumulative toxio effect of submerged oil may beccme very 

 pronounced. 



An oil slick treated with carbonized sand is much more firmly bound 

 and is permanently anchored at the place of deposition. It has no 

 tendency to shift with the currents. In this way, the pollution is 

 localized and its spread is prevented. 



In sinking oil slicks by carbonized sand, the toxic nature of the 

 oil is not appreciably lessened. As a matter of fact, it is brought in 

 close proximity to bottom -dwelling forms where the concentration of 

 leached poisons will be made greater than in the case where the slick 

 is allowed to float freely on the surface. In our harbors and areas 

 close to docks, shipyards, piers, etc., most marine life that is at all 

 sensitive has been either killed or has moved because of pollution by a 

 variety of industrial and domestic wastes. In reality these waters are 

 alnfios t biological deserts. If additional toxio environment is created 

 in such locations by the deposition of oil, very little, if any, increase 

 in damage can be expected over what has already taken place. Indeed, the 

 anchoring of the oil and limiting it to such areas has the distinct 

 advantage of keeping the pollution away from adjacent places that may be 

 productive of economically Importeunt estuarlne forms, suoh as oysters, 

 clams, shrimps, etc. 



It seems logical to assume that carbonized sand will not be used 

 over valuable shellfish-producing beds exoept in emergencies. In the 

 latter case, sane damage may be expected, but if the cfuantities of dis- 

 charged oils are small, the effect may be insignificant and of temporary 

 natijre. 



From our studies we conclude that dusting with carbonized sand is 

 a highly efficient method of removal of oil from the surface of the water. 

 It is useful around docks and piers to combat fire hazards and has also 

 distinct advantage in preventing the movement of oil slicks to productive 

 areas where great injury to sea food resoiirces may occur. We hope that 

 the method will be adopted by the oil industry, especially in active oil 

 fields, and that eventually it will be generally used in combatting oil 

 pollution in coastal waters. 



SmftlARY 



The results of the tests performed wi th a selected group of marine 

 animals may be summarized as follows: 



1. Crude oil, Diesel oil, and Navy Grade Special fuel oil added 

 to sea water are toxic to the hydrpzoem Tubularia crocea; 

 barnacles, Balanus balanoides; embryos of the toadfish, Opsanus 

 tau} and the eastern oyster, Ostrea virginica. The one experiment 



48 



