174 U. S. BUREAU OF FISHERIES 



The effect of oil wast; s on shellfish can be more accurately de- 

 scribed.* During the first part of its existence, before it sets, the 

 young mollusk is a free-swimming larva in the water. During this 

 stage it is especially susceptible to the slightest change in environ- 

 ment. The presence of oil waste Avould cause th^ destruction of these 

 larval forms, which swim immediately beneath the water surface. 

 He believes that oil would kill adult shellfish onl}^ when present in 

 considerable amounts. He explained that the process of setting of 

 oysters may be prevented by any slimy material, and the presence 

 of oil would undoubtedly have a deleterious effect in this respect. 



Tests have shown that adult oysters can be placed in an appreci- 

 able amount of water-gas tar without immediately perishing. Ap- 

 parently no actual deaths of mollusks from oil wastes have been 

 noted by the Massachusetts division of fish and game, but clams have 

 been rendered unpalatable and unfit for food where oil has con- 

 taminated the flats. 



The destructive action of oil pollution on fowl was officially re- 

 port d in California in 1917 and along the eastern coast in 1920 

 and 1921. It is stated that the birds, either in walking on the flats 

 or resting on the oil-covered water of tide pools, come in direct con- 

 tact with the material, which tenaciously sticks to their legs, wings, 

 and on the sides of their bodies. As the bird endeavors to remove 

 this material, its neck, head, and beak become more or less con- 

 taminated with it. The fathers are matted together, and it is 

 stated that when this occurs with the wings the birds become help- 

 less. Apparently they find it impossible to fly, or at least to fly 

 in the normal manner, and they can only walk or roll over the 

 flats. The oil not onlj' causes matting of the feathers, but is re- 

 ported to penetrate to the skin, causing irritation. It is said that 

 a bird thus disabled will inevitably perish. Death is stated to be 

 due to the inability to (1) navigate normally, (2) obtain food, and 

 (3) maintain th ir normal body temperature. 



The vice president of the American Game Protective and Propa- 

 gation Association of New York stated that if birds get only a small 

 spot of oil on them death seems to be just as certain though it comes 

 slowly. He has seen many ducks dead with only a small spot of oil 

 on them, and other birds that had only a small patch of feathers 

 matted with oil. 



PRESENT STATUS OF OIL POLLUTION 



It would appear, therefore, that oil pollution has considerable 

 effect upon the edible qualities of aquatic animals and may affect the 

 migratory habits of fish; it is detrimental to shellfish by reason of 

 destroying the larval forms and rendering the adult mollusks imfit 

 for food. With regard to water fowl, it appears to be a cause of 

 considerable destruction, rendering the birds helpless through its 

 mechanical action on the feathers. It has been stated that Avlien birds 

 are not actually killed as a result of contact with the oil they are ren- 

 dered unfit for food due to the oil taint. 



A survey of the situation along the Atlantic and Gulf coasts in- 

 dicates that adverse conditions due to oil pollution, as affecting 

 marine and wild life, were widespread, practically every important 



* Personal communication to the authors. 



