There is evidence that penguins {Spheniscus demersus) may be repelled by 

 underwater broadcasting of killer whale {Grampus ovca) sounds (Frost et al . 

 1975). Killer whales occur off much of the Canadian and U.S. coasts, and so 

 it is possible that species of birds that dive might be dispersed by killer 

 whale sounds. Because underwater sounds attenuate slowly, this method might 

 be effective over a substantial area. Field trials are needed. 



LEADS AND ICE 



Areas of open water that are surrounded by ice are likely to contain 

 birds, and pools of oil that look like open water are also likely to be attrac- 

 tive to passing birds, particularly if little or no open water is available 

 nearby. 



Methods of dispersing or deterring birds from oil spills in leads, in 

 other areas of water surrounded by ice, or on ice have not been tested. 

 However, available evidence indicates that the potential for dispersing and 

 deterring birds from such areas will depend on the size and remoteness of 

 the oil spill and on whether alternate areas of open water are available. 



In general, three major classes of problems limit the ability to disperse 

 and deter birds from leads and polynias: 



1. Logistics are difficult in remote areas and in open water. 



2. Techniques have not been developed or tested in offshore 

 or icebound waters or against the types of birds that would 

 occur in such areas. 



3. The deterrent effort would have to continue over a long 

 period because of the extreme difficulty of cleanup operations 

 on icebound waters. 



Alleviation of any of these problems could markedly improve the potential 

 for minimizing bird mortality as a result of oil spills near or on ice. 



AREAS NEAR A SEA BIRD COLONY 



Sea bird colonies that occur in North America range in size from a few 

 pairs of birds to hundreds of thousands of birds. If oil is spilled near 

 a large sea bird colony during the breeding season, it is inevitable that 

 large numbers of birds will be killed. 



Sea birds commonly land on the water near their colonies, and are espe- 

 cially likely to do so if the nest sites are disturbed. Research into the 

 efficacy of oil-soluble dyes as bird deterrents is especially desirable for 

 this situation. Standard deterrent methods may also be effective against 

 sea birds in some situations, but no trials have been conducted. Such informa- 

 tion is needed before a realistic contingency plan can be prepared to deal 

 with the case of an oil spill near a colony. 



The primary goal of any attempt to reduce mortality from an oil spill 

 near a colony should be to minimize the number of adults that are oiled, and 

 thereby to maintain the potential for productivity in future years. 



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