TP10 Migrations: Role of Biota in Contaminant Distribution
D135-136
1:20 PM - 4:40 PM, Tuesday
() Environmental contaminants and trophic relations among migratory and resident avifauna from the Aleutian Archipelago, Alaska.
Miles, A1, Ricca, M1, Anthony, R2, 1 U.S. Geological Survey, Western Ecological Research Center, Davis, CA, USA2 Oregon Cooperative Fisheries and Wildlife Research, U.S. Geological Survey, Corvallis, OR, USA
ABSTRACT- Elevated levels of organochlorine pollutants and mercury occur in the nearshore marine community of the Aleutian Archipelago but their source(s) are unknown. We collected migratory and resident seabirds (glaucous-winged gulls, northern fulmars, tufted puffins) and rock ptarmigan along a longitudinal gradient across the central and western Aleutian Islands (Buldir, Kiska, Amchitka, Adak) to test for a westward increase in contaminant concentrations. We collected additional seabird species representing different foraging and migratory guilds from Buldir Island. We used 
15N as a surrogate for trophic level of feeding and examined its association with contaminant concentrations among and across species. Total PCBs were elevated across all islands and highest in glaucous-winged gulls (geomean = 1.1 ppm wet weight) and northern fulmars (0.6 ppm). Concentrations of p,p′DDE were highest in seabirds from Buldir Island (0.12 ppm) and lowest from Amchitka (0.05 ppm). Concentrations of Hg demonstrated the strongest westward increase across islands, especially among glaucous-winged gulls and northern fulmars. Total PCBs (0.3 ppm) and DDE (0.03 ppm) were comparatively lower for tufted puffins and were detected infrequently among rock ptarmigan. Among seabirds collected exclusively at Buldir, pelagic cormorants had comparatively higher Hg concentrations (15 ppm, dry weight). Total PCBs and DDE among species collected only at Buldir were < 1.0 ppm. Enrichment of 15N was highest for glaucous-winged gulls and northern fulmars, and seabirds from Adak. There were few strong associations between 15N and contaminant concentrations within individual species, but significant associations occurred across all seabird species (P < 0.001, R2 > 0.24). Our results provide evidence of comparatively higher contaminant concentrations in the western Aleutians that are influenced by trophic status of seabirds.
Key words: mercury, organochlorine pollutants, seabirds, Aleutian Archiplelago