species composition of egg collections, as well as in levels 
of exposure or other factors at the various sites. Mean con- 
centrations for all chemicals are presented in Appendix ITI, 
and selected comparisons are shown in Table 8. 
There were significant differences among species-mean 
DDE concentrations at seven sites (Table 8). At those sites, 
and at others where the differences were not significant, 
DDE residue concentrations usually were higher in eggs of 
glaucous-winged gull, tufted puffin, northern fulmar, and 
common murre than in those of other species, and usually 
were lower in eggs of black-legged kittiwake, thick-billed 
murre, horned puffin, and cormorant than in those of 
other species that were well enough represented in the 
samples to enable sound comparisons. 
Species-mean PCB concentrations were significantly 
different at nine sites (Table 8). Concentrations of PCB 
residues in eggs usually were higher in glaucous-winged 
gull and tufted puffin, and lower in common murre, 
black-legged kittiwake, and cormorant, than in most 
other species; however, this pattern was not consistent. 
Eggs of ancient murrelet and storm-petrel (both species) 
were compared only at Buldir Island; they contained 
higher mean concentrations of both DDE and PCB’s than 
most other species sampled there. 
The PCB/DDE ratio was usually lower (less than 2.0) in 
eggs of northern fulmar, glaucous-winged gull, murre, 
and tufted puffin than in those of other species (Appendix 
III). The ratio was much higher (often greater than 10.0) 
in black-legged kittiwake than in other species. 
Mean concentrations of other chemicals also often dif- 
fered significantly,among the various species. Detailed in- 
formation (i.e., sample size, number with residues, geo- 
metric mean, 95% confidence interval, and range) is pre- 
sented in Appendix III for each species and collection site. 
We collected at least five eggs per species for two or more 
species at 1] sites. Statistical comparisons of species-means 
for each of these sites are summarized here and in Table 8. 
Hinchinbrook Island. — Residues of DDD, DDT, diel- 
drin, mirex, cis-chlordane, cis-nonachlor, and HCB were 
higher in tufted puffin eggs than in those of glaucous- 
winged gull or black-legged kittiwake, and for dieldrin, 
heptachlor epoxide, and cis-chlordane, levels in kittiwake 
eggs were significantly lower than those in the glaucous- 
winged gull eggs. Toxaphene was highest in glaucous- 
winged gull eggs, but there was no difference between the 
concentrations in kittiwake and puffin eggs. 
Middleton Island.— Residues of DDD, DDT, hepta- 
chlor epoxide, and oxychlordane were highest in common 
murre eggs and lowest in pelagic cormorant and black- 
legged kittiwake eggs. Cis-chlordane and toxaphene were 
significantly higher in pelagic cormorant eggs than in 
those of any other species, and cis-nonachlor in eggs was 
significantly higher in common murre than in glaucous- 
winged gull. 
Kodiak Island. — Residues of DDT were higher in eggs 
of glaucous-winged gull than in black-legged kittiwake, 
and dieldrin was higher in mew gull and glaucous-winged 
gull than in kittiwake. Heptachlor epoxide was higher in 
glaucous-winged gull eggs than in those of other species. 
HCB was higher in tufted puffin and black-legged kitti- 
wake than in either gull species, and toxaphene was higher 
in tufted puffin than in any of the other species. 
Ugaiushak Island. —DDD in eggs was significantly 
higher in tufted puffin than in any other species, and cis- 
chlordane was higher in tufted puffin than in murres. 
However, cis-nonachlor in common murres and HCB in 
thick-billed murres were higher than in the other species. 
Heptachlor epoxide was significantly higher in glaucous- 
winged gull eggs than in those of tufted puffins, and oxy- 
chlordane was higher in glaucous-winged gull eggs than in 
tufted puffin and common murre eggs. 
Semidi Islands.— DDD in eggs was significantly higher 
in tufted puffins than in glaucous-winged gulls or northern 
fulmars; dieldrin and mirex were significantly higher in 
gulls than in either of the other species. Residues of DDT 
were higher in northern fulmar eggs than in gull or puffin 
eggs. Concentrations of heptachlor epoxide, cis-chlordane, 
and HCB in eggs were significantly higher in glaucous- 
winged gull and tufted puffin than in the fulmar. 
Shumagin Islands.—DDD and cis-chlordane were sig- 
nificantly higher in tufted puffin eggs than in glaucous- 
winged gull eggs, but there were no significant differences 
in residues among eggs of these species in any of the other 
chemicals, 
Buldir Island. —DDD, DDT, dieldrin, mirex, oxychlor- 
dane, cis-chlordane, and toxaphene were significantly 
higher in eggs of fork-tailed storm-petrel than in those of 
Leach’s storm-petrel, ancient murrelet, or thick-billed 
murre. Toxaphene in eggs was also higher in Leach’s 
storm-petrels than in thick-billed murres, but there were 
no other significant differences among these species for 
these chemicals. Heptachlor epoxide and cis-nonachlor 
were higher in ancient murrelets than in any of the other 
species, and cis-nonachlor also was higher in eggs of 
Leach’s storm-petrels than in those of fork-tailed storm- 
petrels or thick-billed murres. However, the concentration 
of HCB in eggs was higher in thick-billed murre than in 
ancient murrelet. 
Shaiak Island. —Mirex and cis-chlordane were signifi- 
cantly higher in tufted puffin than in common murre eggs, 
but there were no significant differences between those 
species for the other chemicals. 
St. George Island. —Concentrations of DDD and hep- 
tachlor epoxide were higher in eggs of common murres 
than in those of northern fulmars, but levels of oxychlor- 
dane, cis-chlordane, and cis-nonachlor were higher in eggs 
of the fulmar than in those of the murre. 
St. Paul Island.—Dieldrin, heptachlor epoxide, and 
HCB were significantly higher in common murre than in 
black-legged kittiwake eggs; oxychlordane was higher in 
the kittiwakes than in the murres. 
Bluff Seabird Cliffs. — Concentrations of DDD, oxy- 
chlordane, and HCB in eggs were significantly higher in 
common murre than in black-legged kittiwake. 
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