30 



Plastic particles have been found in the 

 stomachs of fork-tailed petrels, horned 

 puffins (Fratercula corniculata), and parakeet 

 auklets (Cyclorrhynchus psittacula) from the 

 Aleutians (G. J. Divoky and C. M. White, per- 

 sonal communication), as well as in the 

 stomachs of adult and nestling Leach's 

 petrels from Newfoundland and New Bruns- 

 wick (Rothstein 1973). 



Gulls and terns regurgitate indigestible 

 parts of their food, such as bits of shell and 

 fish bones. Polystyrene particles have also 

 been found in these pellets (Hays and Cor- 

 mons 1974). 



It is not known whether the birds ingest the 

 plastic particles directly, but petrels appar- 

 ently do. Other marine birds may acquire par- 

 ticles in their stomachs by consuming fish 

 that have previously ingested the plastic 

 particles. 



Evidence of harmful effects of plastic par- 

 ticles to any species is lacking, except for the 

 possibility of intestinal blockage in smaller 

 fish (Carpenter et al. 1972). However, they do 

 accumulate in the environment, are eaten by 

 fish, and are found in the stomachs of marine 

 birds. It has been suggested that the plastics 

 industry develop products that are degrad- 

 able, but the most likely outcome of such an 

 effort would be introduction of finished prod- 

 ucts that would disintegrate into smaller 

 particles similar to those described here (Hays 

 and Cormons 1974). 



Rubber thread cuttings may represent a 

 hazard to marine birds. Common puffins, in 

 particular, appear to mistake them for fish 

 and swallow them. These elastic threads form 

 knots and the tangled mass may remain in the 

 stomach. In one case the entangled elastic 

 was tightly packed into the gizzard exit; in an- 

 other it had formed a ball of rubber in the 

 gizzard itself. Although the rubber threads 

 may not kill the birds, there is a possibility 

 that they make them less able to withstand 

 other stresses (Parslow and Jefferies 1972). 



Although other artifacts, such as trash 

 scattered on beaches or jetsam washed 

 ashore, may contribute significantly to the 

 mortality of certain species of marine birds 

 (Gochfeld 1973), in other circumstances, such 

 debris may enhance the habitability of an 

 area. An apparent increase in the number of 

 black guillemots breeding in the Barrow, 

 Alaska, area appears to be associated with the 



local increase in man-made debris. The birds 

 typically nest in cavities in rock cliffs and 

 crevices in talus slopes. Because such nest 

 sites are absent in the Barrow area, guille- 

 mots have nested in an empty oil drum, under 

 a collapsed building, and under other types of 

 man-made debris (Divoky et al. 1974). 



No explanation has been found for the ap- 

 pearance along the Northumberland (United 

 Kingdom) coast of severely debilitated 

 common murres whose plumage has been ex- 

 tensively abraded. Fluoride, discharged by a 

 nearby aluminum smelter, was considered a 

 possible cause because the birds had a strong 

 odor resembling chlorine, another closely re- 

 lated halogen compound. There also were 

 similarities between the signs observed in the 

 affected birds and those observed in cases of 

 acute or chronic fluorosis in other animals. 

 The implication of fluoride was dismissed, 

 however, in part, on the basis of low fluoride 

 residue levels in bone, skin, internal organs, 

 and digestive tract of the affected birds. Fur- 

 ther, normal murre feathers were not dam- 

 aged by soaking in various fluorine com- 

 pounds, in samples of smelter effluent, and in 

 undiluted scrubber liquid (Croxall 1972). 



Recommendations 



The levels of any pollutant, or combination 

 of pollutants, in the marine environment 

 should remain below a level that damages the 

 viability of any population or species of ma- 

 rine bird. Thus the global use of organo- 

 chlorine compounds must be regulated, if nec- 

 essary, to restrict input into the sea. The 

 undersea exploitation of petroleum, the 

 marine transport of petroleum, and the ac- 

 tivities of coastal refining and petrochemical 

 industries must also be regulated to prevent 

 harm to local populations of marine birds. 



Much remains to be learned about the expo- 

 sure of marine birds to environmental pollu- 

 tants in northern North America. The most 

 critical areas for study include the effects of 

 chronic sublethal exposure to petroleum hy- 

 drocarbons, certain organochlorines, and mer- 

 cury. The possible synergistic effects of these 

 compounds in marine birds should also be in- 

 tensively studied. 



A long-term program to monitor increasing 

 or decreasing levels of any particular pollu- 



