

Table 6. Continued 




Geometric 
Species, compound and site mean@ 
Cis-chlordane? 
Barren Islands 0.030 A 
Hinchinbrook Island 0.023 AB 
Shumagin Islands 0.018 ABC 
Semidi Islands 0.014 BC 
Ugaiushak Island 0.013 C 
Kodiak Island 0.012 C 
Shaiak Island 0.008 C 
Cis-nonachlor 
Hinchinbrook Island 0.014 A 
Barren Islands 0.009 AB 
Shaiak Island 0.006 B 
Ugaiushak Island 0.006 Bd 
Semidi Islands 0.004 B 
Kodiak Island 0.003 B 
Shumagin Islands 0.003 B 
HCB 
Shaiak Island 0.064 A 
Shumagin Islands 0.037 B 
Hinchinbrook Island 0.036 B 
13 


Geometric 


Species, compound and site mean@ 
Barren Islands 0.033 B 
Semidi Islands 0.032 B 
Ugaiushak Island 0.029 B 
Kodiak Island 0.024 B 
Toxaphene 
Kodiak Island 0.065 A 
Shumagin Islands 0.018 B 
Ugaiushak Island 0.015 B 
Semidi Islands 0.003 B 
Hinchinbrook Island ND B 
Barren Islands ND B 
Shaiak Island ND B 
PCB’s 
Hinchinbrook Island 0.625 A 
Barren Islands 0.574 A 
Kodiak Island 0.533 A 
Ugaiushak Island 0.531 A 
Shumagin Islands 0.524 AB 
Shaiak Island 0.423 AB 
Semidi Islands 0.263 B 



aFor each species, means that do not share the same letter are significantly different (P< 0.05) from each other (each compound con- 
sidered separately). 
bOr trans-nonachlor, or both (see Methods). 
‘ND = not detected in these samples. 
dMean reflects collections in two years with differences among years; see Appendix III. 
legged kittiwakes in the Aleutian Islands (0.718), and 
common murres in the Pribilof Islands (0.579), although 
the average for these species for all regions was low. 
Mean concentrations of DDE and PCB’s on a regional 
basis varied significantly among species, but there were 
few consistent patterns of species differences (Table 7). 
However, black-legged kittiwakes (when they were repre- 
sented) always had the lowest levels of DDE, and murres 
usually had low concentrations of PCB’s. Northern ful- 
mars usually were in the group that had higher concentra- 
tions of both chemicals (except PCB’s in the Gulf of Alaska) 
than other species, and glaucous-winged gulls in the Aleu- 
tian Islands had concentrations of both DDE and PCB's 
that were clearly higher than those in the other species. 
Frequency of Residue Occurrence by Species 
Residues of DDT and oxychlordane were found in each 
of the northern fulmar eggs (Table 3), whereas the fre- 
quency of these chemicals was lower in other species (ex- 
cept for oxychlordane in the Pribilof Islands) where the 
fulmar eggs were taken. For heptachlor epoxide, cis-chlor- 
dane, and cis-nonachlor, frequency of occurrence in the 
fulmar eggs was lower than the average for all species 
combined. 
Except for DDE, heptachlor epoxide, and toxaphene (in 
the Gulf of Alaska only), frequencies of all chemicals in 
fork-tailed storm-petrel eggs were considerably higher 
than the average for all species (Table 3). In Leach’s storm- 
petrel the frequency of most chemicals (except cis-chlor- 
dane and those found in all storm-petrel eggs) was some- 
what lower than in fork-tailed storm-petrels. However, 
frequency of DDD, DDT, cis-chlordane, cis-nonachlor, 
HCB, and toxaphene in Leach’s storm-petrel eggs was 
above the average for all species in the Aleutian Islands. 
Mirex and endrin were the only chemicals not detected in 
petrels. 
Frequencies of most chemicals were low in cormorant 
eggs from most regions (Table 3); however, we were 
usually not able to collect a series of eggs large enough to 
enable sound comparisons. The exception was for pelagic 
cormorants from the Gulf of Alaska, where eggs from 11 
clutches were collected. In those eggs, the frequency of 
DDD and HCB was lower than the averages for all species 
from that region, but the frequency for other chemicals 
was at least as great as the overall average. 
In the Gulf of Alaska, the frequency of DDD, DDT, 
mirex, oxychlordane, cis-nonachlor, and toxaphene was 
slightly lower in glaucous-winged gull eggs than in all 
species combined (Table 3), and five of the gull eggs from 

