Environmental contaminants in bald eagle eggs?1980?84?and further interpretations of relationships to productivity and shell thickness

Wiemeyer, Stanley N.; Bunck, Christine M.; Stafford, Charles J.

doi:10.1007/bf01141351

Cited by 113 publications

(87 citation statements)

References 20 publications

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“…Many ecosystems are now impacted by chronic levels of many contaminants rather than acute levels of a single critical contaminant, and therefore understanding the robustness of results to modelselection when several contaminants are present is an important result. Use of cAIC or AIC gave almost identical orders for model selection, and AIC appears to be an adequate tool for contaminant studies, at least where sample sizes (60-200, depending on the analysis) and number of parameters (8)(9)(10)(11)(12), depending on the analysis) were similar to ours.…”

Section: Mechanisms Of Contaminant Effectsmentioning

confidence: 69%

Productivity, embryo and eggshell characteristics, and contaminants in bald eagles from the Great Lakes, USA, 1986 to 2000

Best

Elliott

Shieldcastle

et al. 2010

Enviro Toxic and Chemistry

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Chlorinated hydrocarbon concentrations in eggs of fish-eating birds from contaminated environments such as the Great Lakes of North America tend to be highly intercorrelated, making it difficult to elucidate mechanisms causing reproductive impairment, and to ascribe cause to specific chemicals. An information- theoretic approach was used on data from 197 salvaged bald eagle (Haliaeetus leucocephalus) eggs (159 clutches) that failed to hatch in Michigan and Ohio, USA (1986-2000). Contaminant levels declined over time while eggshell thickness increased, and by 2000 was at pre-1946 levels. The number of occupied territories and productivity increased during 1981 to 2004. For both the entire dataset and a subset of nests along the Great Lakes shoreline, polychlorinated biphenyls (SigmaPCBs, fresh wet wt) were generally included in the most parsimonious models (lowest-Akaike's information criterion [AICs]) describing productivity, with significant declines in productivity observed above 26 microg/g SigmaPCBs (fresh wet wt). Of 73 eggs with a visible embryo, eight (11%) were abnormal, including three with skewed bills, but they were not associated with known teratogens, including SigmaPCBs. Eggs with visible embryos had greater concentrations of all measured contaminants than eggs without visible embryos; the most parsimonious models describing the presence of visible embryos incorporated dieldrin equivalents and dichlorodiphenyldichloroethylene (DDE). There were significant negative correlations between eggshell thickness and all contaminants, with SigmaPCBs included in the most parsimonious models. There were, however, no relationships between productivity and eggshell thickness or Ratcliffe's index. The SigmaPCBs and DDE were negatively associated with nest success of bald eagles in the Great Lakes watersheds, but the mechanism does not appear to be via shell quality effects, at least at current contaminant levels, while it is not clear what other mechanisms were involved.

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Section: Mechanisms Of Contaminant Effectsmentioning

confidence: 69%

Productivity, embryo and eggshell characteristics, and contaminants in bald eagles from the Great Lakes, USA, 1986 to 2000

Best

Elliott

Shieldcastle

et al. 2010

Enviro Toxic and Chemistry

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“…An NOEL of 4 lg g À1 ww for RPCBs in bald eagle (Falconiformes specie) was reported by Wiemeyer et al (1993), associated with productivity and shell thickness. McLane and Hughes (1980) suggested an NOEL of 7 lg g À1 ww for screech owls exposed to Aroclor 1248 via diet.…”

Section: Contaminant Levels and Toxicological Significancementioning

confidence: 97%

Occurrence and biomagnification of organohalogen pollutants in two terrestrial predatory food chains

Luo

Zheng

et al. 2013

Chemosphere

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“…Other data showed that adult bald eagles found dead and eagle egg samples from near bleached-kraft pulp mill sites in the Strait of Georgia had high PCDD and PCDF levels [23,24]. During the period from the early 1950s to the late 1970s, bald eagle populations declined in many areas of North America as a result of the eggshell thinning effects of DDT and toxic effects of other chlorinated hydrocarbons [25][26][27]. Eagle productivity has generally improved throughout most of North America as environmental DDT levels declined [28], but eagles in areas of high DDE and PCB concentrations still exhibit poor breeding success [29,30].…”

Section: Introductionmentioning

confidence: 99%

Biological effects of polychlorinated dibenzo‐p‐dioxins, dibenzofurans, and biphenyls in bald eagle (Haliaeetus leucocephalus) chicks

Elliott

Hart²,

Cheng³

et al. 1996

Enviro Toxic and Chemistry

101

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Abstract-During the 1992 breeding season, eggs of bald eagles (Haliaeetus leucocephalus) were collected within a gradient of exposure to chlorinated hydrocarbon pollutants, particularly from pulp mill point sources, on the southern coast of British Columbia, Canada. Twenty-five eggs were placed in a laboratory incubator, of which 18 hatched; chicks were sacrificed within 24 h. Hatching success was not significantly different between eggs taken from pulp mill sites and reference sites. A hepatic cytochrome P4501A (CYP1A) cross-reactive protein was induced nearly sixfold in chicks from near a pulp mill at Powell River compared to those from a reference site (p Ͻ 0.05). Hepatic ethoxyresorufin-O-deethylase (EROD) and benzyloxyresorufin O-dealkylase (BROD) activities were also significantly elevated in chicks from nests located near pulp mills compared to reference sites (p Ͻ 0.0005 and p Ͻ 0.02, respectively). A hepatic CYP2B cross-reactive protein was threefold higher in chicks from pulp mill versus reference sites, but the difference was not significant. Residual yolk sacs of eggs collected near pulp mill sites contained greater concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) compared to reference areas. No significant differences in concentrations of polychlorinated biphenyls (PCBs), non-ortho congeners, and organochlorine pesticides occurred among sites. Regressions showed that the hepatic CYP1A cross-reactive protein and EROD and BROD activities were positively correlated with 2,3,7,8-TCDD, 2,3,7,8-TCDF, and toxic equivalents (TEQs WHO -World Health Organization toxic equivalence factors) in yolk sacs. No significant concentration-related effects were found for morphological, physiological, or histological parameters, such as chick growth, edema, or density of thymic lymphocytes. Using hepatic CYP1A induction as a biomarker, a no-observedeffect-level (NOEL) of 100 ng/kg and a lowest-observed-effect-level (LOEL) of 210 ng/kg TEQs WHO on a whole egg (wet weight basis) are suggested for bald eagle chicks.

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Environmental contaminants in bald eagle eggs?1980?84?and further interpretations of relationships to productivity and shell thickness

Cited by 113 publications

References 20 publications

Productivity, embryo and eggshell characteristics, and contaminants in bald eagles from the Great Lakes, USA, 1986 to 2000

Productivity, embryo and eggshell characteristics, and contaminants in bald eagles from the Great Lakes, USA, 1986 to 2000

Occurrence and biomagnification of organohalogen pollutants in two terrestrial predatory food chains

Biological effects of polychlorinated dibenzo‐p‐dioxins, dibenzofurans, and biphenyls in bald eagle (Haliaeetus leucocephalus) chicks

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