EFFECTS OF OIL ON AQUATIC BIRDS 



Peter H. Albers 1 



The lethal effect of spilled oil on seabirds was reported as early as 

 1910 (Bourne 1968). Large numbers of birds have since been killed or disabled 

 by oil spills (National Academy of Sciences 1975), and the associated patho- 

 logical conditions have been described (Hartung and Hunt 1966, Snyder et 

 al . 1973). Birds that spend a great deal of time on the water, such as the 

 Alcids and seaducks, are the most vulnerable to surface oil; birds that spend 

 much of their time airborne, such as gulls and terns, are the least vulnerable 

 (Bourne 1968, Vermeer and Anweiler 1975). The vulnerability of a given species 

 to surface oil may vary seasonally according to breeding activities, migration, 

 and feather molt. Although there are some cases where bird populations have 

 apparently been severely reduced as a result of oil spillage, reliable popula- 

 tion estimates for the affected species are usually scarce (Bourne 1968, 

 Joensen 1972, and Vermeer 1976). 



The plight of birds affected by oil spills attracts much public attention, 

 but not more than 30 to 40 percent of the petroleum in the marine environment 

 comes from accidental spills. Continual discharges from industrial plants, 

 refineries, urban runoff, internal combustion engines, and natural oil seepage 

 account for the remaining 60 to 70 percent (National Academy of Sciences 1975, 

 Grossling 1976). Continual discharges from normal petroleum use are thought 

 to account for an even greater proportion of the oil in inland waters (Grossling 

 1976). We have some evidence of the impact of direct mortality from oil 

 spills on bird populations, but we know \/ery little about the sublethal and 

 indirect effects of oil on birds. 



Research at the Patuxent Wildlife Research Center, Laurel, Maryland, 

 is directed at (1) determining the effects of petroleum on the physiology 

 and reproductive success of birds, and (2) developing the analytical methodology 

 necessary for detection of petroleum in avian tissues. 



PHYSIOLOGY 



Physiological studies underway at Patuxent are evaluating the effects 

 of petroleum on hepatic, cardiac, and renal functions. The effects of petroleum 

 on hepatic function are under close scrutiny because the liver represents 

 the primary site of detoxification and excretion of toxic compounds. Hartung 

 and Hunt (1966) measured hepatic function of Pekin ducks {Anas platyrhynchos) 

 24 h after dosage with 3 to 24 ml/kg of diesel oil. They found dose-related 

 evidence of liver damage and decreased liver function. 



Patuxent Wildlife Research Center 

 U.S. Fish and Wildlife Service 

 Laurel, Maryland 20811 



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