12 



dues ranged from 8 to 20 ppb (White and 

 Risebrough 1977). Residues of DDE in seven 

 species of fish obtained from the coastal 

 waters of Iceland in 1973 ranged from 1 to 

 9 ppb; PCB levels ranged from 8 to 20 ppb 

 (J. A. Sproul et al., unpublished manuscript). 

 On a lipid basis, PCB residues expressed as 

 tri-, tetra-, or penta-chlorobiphenyls ranged 

 from 0.3 to 2 ppm in the Amchitka fish and 

 from 0.2 to 3 ppm in the Icelandic fish. Body 

 fat of great cormorants from Greenland 

 (Braestrup et al. 1974) contained comparable 

 PCB levels and somewhat higher DDE levels 

 than great cormorants from Iceland. 



A comparison of DDE and PCB residue 

 levels in black-legged kittiwakes (Rissa tridac- 

 tyla), fulmars (Fulmarus glacialis), and thick- 

 billed murres (Uria lomvia) from Amchitka 

 and Iceland suggests somewhat higher levels 

 in the Icelandic birds, although residues are of 

 the same order of magnitude and with com- 

 parable ratios (J. A. Sproul et al., unpublished 

 manuscript; White and Risebrough 1977). The 

 differences may reflect a higher level of con- 

 tamination in those areas of the ocean where 

 the Atlantic birds spend the winter months. 



Earlier data (Risebrough et al. 1968) sug- 

 gested that DDT compounds were more abun- 

 dant than PCB's in Pacific waters. However, 

 many of the samples were from coastal Cali- 

 fornia waters where DDT contamination was 

 particularly severe. 



Residue levels and PCB:DDE ratios in the 

 breast muscles of Icelandic birds obtained in 

 1973 were comparable to those in birds ob- 

 tained earlier from areas north of Britain, in- 

 dicating that no decline in residue concentra- 

 tions in birds had occurred over that short 

 interval (Bourne and Bogan 1972; J. A. 

 Sproul et al., unpublished manuscript). 



From the Pacific, the visceral fat of 7 black- 

 footed albatrosses (Diomedea nigripes) and 

 22 Laysan albatrosses (D. immutablis) from 

 Midway Island contained mean DDE levels of 

 22 and 8 ppm, and mean PCB levels of 14 and 

 2 ppm (Fisher 1973). These species are re- 

 stricted to the North Pacific, usually about 

 20 N and feed primarily on squid. In Hawaii, 

 DDE concentrations in four eggs of the dark- 

 rumped petrel (Pterodroma phaeopygia) 

 ranged from 0.07 to 1.14 ppm (0.6-11.5 ppm, 

 lipid weight) (King and Lincer 1973). PCB 

 values were not reported. 



From the tropical Atlantic, DDE and PCB 



levels in the breast muscle of 28 adult sooty 

 terns (Sterna fuscata), breeding on the Dry 

 Tortugas, were 2.5 and 7.8 ppm (lipid weight); 

 mean percentage of lipid was 2.6% (P. G. 

 Connors et al., unpublished manuscript). 



In these areas of the Atlantic and Pacific, 

 comparatively remote from sources of con- 

 tamination, PCB residue concentrations gen- 

 erally exceeded those of the DDT compounds. 

 In the New Zealand (including the sub-Ant- 

 arctic islands) samples, however, DDT resi- 

 dues were frequently present at higher con- 

 centrations than the sum of PCB's (Benning- 

 ton et al. 1975). 



In the Antarctic, few eggs of the Adelie pen- 

 guin obtained in 1970 or earlier from widely 

 separated localities contained PCB's at de- 

 tectable levels (Risebrough et al. 1976a). 

 Maximum amounts of PCB's in eggs of the 

 Adelie penguin obtained from Cape Crozier in 

 October 1967 were less than one-eighteenth of 

 the concentration of DDT compounds (Rise- 

 brough et al. 1968). Subsequent analysis of 

 some of these eggs revealed the presence of 

 PCB. PCB's were detected also in eggs of the 

 Adelie penguin, chinstrap penguin (Pygo- 

 scelis antarctica), and the gentoo penguin (P. 

 papua) obtained in the Antarctic Peninsula in 

 1975, although at concentrations less than 

 those of the DDT compounds (Risebrough et 

 al. 1976b). The preponderance of DDT com- 

 pounds in the Antarctic, the most remote area 

 receiving chlorinated hydrocarbons from at- 

 mospheric or oceanic transport, apparently 

 reflects the relative use of these two groups of 

 compounds in the southern hemisphere. 



In coastal areas local conditions usually de- 

 termine the contamination patterns. For 

 example, liquid chemical wastes discharged 

 by insecticide manufacturing plants in Cali- 

 fornia and the Netherlands subsequently en- 

 tered the sea and caused significant organo- 

 chlorine contamination of coastal birds. High 

 DDT concentrations were found in northern 

 anchovies (Engraulis mordax) from Los An- 

 geles Harbor in 1965 (Risebrough et al. 1967). 

 Subsequent investigations documented ex- 

 ceptionally high levels of DDT compounds in 

 the coastal birds, including the brown peli- 

 cans (Risebrough 1972; Anderson et al. 1975) 

 and double-crested cormorants (Gress et al. 

 1973). When the company began to dispose of 

 its liquid wastes in a sanitary landfill in 1970, 

 input of DDT compounds into the sea began 



