Metals and radionuclides in birds and eggs from Amchitka and Kiska Islands in the Bering Sea/Pacific Ocean ecosystem

Abstract

Metals and radionuclide levels in marine birds of the Aleutians are of interest because they are part of subsistence diets of the Aleut people, and can also serve as indicators of marine pollution. We examined geographic and species-specific variations in concentrations of radionuclides in birds and their eggs from Amchitka, the site of underground nuclear tests from 1965 to 1971, and Kiska Islands (a reference site) in the Aleutians, and the levels of lead, mercury and cadmium in eggs. In 2004 we collected common eiders (Somateria mollissima), tufted puffins (Fratercula cirrhata), pigeon guillemot (Cepphus columba) and glaucous-winged gulls (Larus glaucescens) from Amchitka and Kiska, and eggs from eiders and gulls from the two island. We also collected one runt bald eagle (Haliaeetus leucocephalus) chick from both Amchitka and Kiska Islands. For most species, the levels of radionuclide isotopes were below the minimum detectable activity levels (MDA). Out of 74 cesium-137 analyses, only one composite (gulls) was above the MDA, and out of 14 composites tested for plutonium (Pu-239, 240), only one exceeded the MDA (a guillemots). Three composites out of 14 tested had detectable uranium-238. In all cases, the levels were low and close to the MDAs, and were below those reported for other seabirds. There were significant interspecific differences in metal levels in eggs: gulls had significantly higher levels of cadmium and mercury than the eiders, and eiders had higher levels of lead than gulls. There were few significant differences as a function of island, but eiders had significantly higher levels of cadmium in eggs from Kiska, and gulls had significantly higher levels of mercury on Kiska. The levels of cadmium and mercury in eggs of eiders and gulls from this study were above the median for cadmium and mercury from studies in the literature. The levels of mercury in eggs are within the range known to affect avian predators, but seabirds seem less vulnerable to mercury than other birds. However, the levels of mercury are within the action levels for humans, suggesting some cause for concern if subsistence Aleuts eat a large quantity of eggs.

Mercury and Other Metals in Feathers of Common Eider (Somateria mollissima) and Tufted Puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska

“…In a related study examining radionuclides and mercury in gulls ( Larus glaucescens ) and eiders ( Somateria mollissima ) from these same islands, we found that gull feather ( L. glaucescens ) levels were significantly higher for lead and manganese on Kiska than on Amchitka (Burger and Gochfeld 2007; Burger et al 2008). Thus, the finding of higher levels of lead on Kiska than on Amchitka was consistent for feathers of eiders, gulls, and puffins, birds of different trophic levels.…”

Mercury and other metals in eggs and feathers of glaucous-winged gulls (Larus glaucescens) in the Aleutians

“…However, in a related study examining radionuclides and mercury in gull and eider ( Somateria mollissima ) eggs from these same islands, we found that gulls had significantly higher levels of mercury on Kiska than on Amchitka (Burger and Gochfeld 2007), but we did not analyze eggs from Adak (the island inhabited by Aleuts), nor did we analyze arsenic, chromium, manganese or selenium. Braune et al (2002) examined mercury levels in eggs of glaucous-winged gulls from the High Arctic, and showed that mercury levels increased with latitude; mercury levels ranged from 600 ppm to 4,900 ppm.…”

Pattern of mercury accumulation in different tissues of migratory and resident birds: Western reef heron (Egretta gularis) and Siberian gull (Larus heuglini) in Hara International Wetland—Persian Gulf

“…In tissues of seabirds from the Persian Gulf, concentrations of mercury in tissues of migratory birds were considerably higher than in resident birds (ZamaniAhmadmahmoodi et al 2009). Gulls had significantly higher levels of mercury than the eiders in the Bering Sea, and interspecific differences were detected due to differences in diet (Burger and Gochfeld 2007). Siberian gulls had greater metal concentrations in kidney, liver, pectoral muscle, and feather than Western reef heron from southern Iran (Mansouri et al 2012a, b).…”