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At least 901 records · Page 50Linked to original sources
USGS1990

Eggshell thinning and contaminant levels in bald eagle eggs from Arizona, 1977 to 1985

The mean eggshell thickness of 11 eggs of bald eagles (Haliaeetus leuccocephalus) and 21 samples of eggshell fragments (n = 32) collected from 14 nests in Arizona during 1977 to 1985 was 0.539 mm, 8.8% thinner than the pre-1947 (pre-DDT) mean for eggs from southern California and Baja California, Mexico. Eleven eggs analyzed for contaminants contained slightly elevated concentrations of DDE (3.3pmm wet weight) and mercury (0.14 ppm). Productivity of sampled pairs was low but improving. The predictive equations of Wiemeyer et al. (1984) were also verified.

Southwestern Naturalist↗
USGS1989

Food habits and organochlorine contaminants in the diet of olivaceous cormorants in Galveston Bay, Texas

More than 1,000 food items, representing 32 species of fish and one invertebrate, were identified from olivaceous cormorants. Six species of fish comprised 79% of the diet by frequency of occurrence and 78% by weight. Almost half of the diet consisted of a single species, the sheepshead minnow. Concentrations of pp-dichlorodiphenyldichloroethylene (DDE) in cormorant carcasses were 27 times greater than those in fish and 57 times higher in cormorant eggs than fish. Concentrations of polychlorinated biphenyl (PCB) were 18 times higher in carcasses and 15 times higher in eggs than in fish. The biomagnification of other organochlorine contaminants through the cormorant food base in Galveston Bay is difficult to evaluate because the only compounds detected in all three tissues at greater than 50% frequency of occurrence were DDE and PCB.

Southwestern Naturalist↗
USGS1990

Western grebe, Aechmophorus occidentalis, wintering biology and contaminant accumulation in Commencement Bay, Puget Sound, Washington

Western Grebes wintering at the head of Commencement Bay (bordering the waterways) accumulated significant amounts of mercury, arsenic, DDE, PCBs, chlordanes, and perhaps cadmium and HCB between 17 October 1985 and 6 February 1986. No change in selenium or lead was detected, but copper declined significantly. Western Grebes were likely to accumulate even higher levels of certain contaminants because they remained in Commencement Bay for an additional 3 months after the final collection. Remige moult and bursa length were used to separate five individuals believed to represent one age class, from the remainder of the October collection. These birds, perhaps nonbreeders spending one continuous year in Puget Sound, contained the 5 highest PCB, 5 of the 8 highest DDE, and 2 of the 3 highest mercury concentrations. No evidence was found in the literature to suggest the contaminant concentrations we reported would adversely impact the Western Grebe population. As expected, lipid content of carcasses increased significantly from October (15.5%) to February (28.8%).

Canadian Field-Naturalist↗