Environmental contaminants in prey and tissues of the peregrine falcon in the Big Bend Region, Texas, USA

Mora, Miguel A.; Skiles, Raymond; McKinney, Brad; Paredes, Marcos; Buckler, Denny R.; Papoulias, Diana M.; Klein, David R.

doi:10.1016/s0269-7491(01)00207-x

Cited by 31 publications

(14 citation statements)

References 7 publications

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“…Conversion of 0.6 and 3.9 mg/g to wet weight values yields 0.23 and 1.50 mg/g, respectively. Mercury concentrations of peregrine falcon prey were reported to be 0.85 and 1.75 mg/g (wet wt) for background and premining sites, respectively, and the dietary concentrations used in the current study are also comparable to reports of prey Hg concentrations collected from the lower Carson River valley [11,34]. Comparison of blood concentrations of adult birds in heavily contaminated regions of the United States indicated that blood Hg ranged from 0.1 to 7.8 mg/g (wet wt) in common loons, from 2.79 to 14.17 mg/g in snowy egrets and blackcrowned night herons, and from 11.7 to 22.0 mg/g (wet wt) for double-crested cormorants that fed on prey with 0.36 to 1.18 mg/ g (wet wt) concentrations [11,35].…”

Section: Uptake Of Mehg From the Dietsupporting

confidence: 82%

Toxic effects of dietary methylmercury on immune function and hematology in American kestrels (Falco sparverius)

Fallacara

Halbrook

French

2011

Enviro Toxic and Chemistry

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Fifty-nine adult male American kestrels (Falco sparverius) were assigned to one of three diet formulations including 0 (control), 0.6, and 3.9 µg/g (dry wt) methylmercury (MeHg). Kestrels received their diets daily for 13 weeks to assess the effects of dietary MeHg on immunocompetence. Immunotoxic endpoints included assessment of cell-mediated immunity (CMI) using the phytohemagglutinin (PHA) skin-swelling assay and primary and secondary antibody-mediated immune responses (IR) via the sheep red blood cell (SRBC) hemagglutination assay. Select hematology and histology parameters were evaluated to corroborate the results of functional assays and to assess immunosuppression of T and B cell-dependent components in spleen tissue. Kestrels in the 0.6 and 3.9 µg/g MeHg groups exhibited suppression of CMI, including lower PHA stimulation indexes (p = 0.019) and a 42 to 45% depletion of T cell-dependent splenic lymphoid tissue (p = 0.006). Kestrels in the 0.6 µg/g group exhibited suppression of the primary IR to SRBCs (p = 0.014). MeHg did not have a noticeable effect on the secondary IR (p = 0.166). Elevation of absolute heterophil counts (p < 0.001), the heterophil to lymphocyte ratio (p < 0.001), and total white blood cell counts (p = 0.003) was apparent in the 3.9 µg/g group at week 12. Heterophilia, or the excess of heterophils in peripheral blood above normal ranges, was apparent in seven of 17 (41%) kestrels in the 3.9 µg/g group and was indicative of an acute inflammatory response or physiological stress. This study revealed that adult kestrels were more sensitive to immunotoxic effects of MeHg at environmentally relevant dietary concentrations than they were to reproductive effects as previously reported.

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Section: Uptake Of Mehg From the Dietsupporting

confidence: 82%

Toxic effects of dietary methylmercury on immune function and hematology in American kestrels (Falco sparverius)

Fallacara

Halbrook

French

2011

Enviro Toxic and Chemistry

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“…Elevated concentrations of Hg are well documented in Elephant Butte Reservoir (Ong et al, 1991;Caldwell et al, 1999;Schmitt et al, 1999b;Canavan et al, 2000) and elsewhere in the RGB. Mercury, along with Se, is suspected of having caused the reproductive failure of peregrine falcons (Falco peregrinus) in Trans-Pecos Texas (Mora et al, 2002), where cinnabar was mined historically (Sharpe, 1980). Concentrations of Hg were N0.3 Ag/g in at least one sample from Stations 513 and 514, which may represent a threat to piscivorous birds, and at least one sample from all other stations except Stations 64 and 516 exceeded 0.1 Ag/g, a level that may represent a threat to piscivorous mammals (Yeardley et al, 1998;Wiener et al, 2002).…”

Section: Exposure Indicatorsmentioning

confidence: 99%

Environmental contaminants and biomarker responses in fish from the Rio Grande and its U.S. tributaries: Spatial and temporal trends

Schmitt

Hinck

Blazer³

et al. 2005

Science of The Total Environment

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Dethloff, Gail M.; Bartish, Timothy M.; Coyle, James J.; and Tillitt, Donald E., "Environmental contaminants and biomarker responses in fish from the Rio Grande and its U.S. tributaries: Spatial and temporal trends" (2005 AbstractWe collected, examined, and analyzed 368 fish of seven species from 10 sites on rivers of the Rio Grande Basin (RGB) during late 1997 and early 1998 to document temporal and geographic trends in the concentrations of accumulative contaminants and to assess contaminant effects on the fish. Sites were located on the mainstem of the Rio Grande and on the Arroyo Colorado and Pecos River in Texas (TX), New Mexico (NM), and Colorado. Common carp (Cyprinus carpio) and largemouth bass (Micropterus salmoides) were the targeted species. Fish were examined in the field for internal and external visible gross lesions, selected organs were weighed to compute ponderal and organosomatic indices, and samples of tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Whole fish from each station were composited by species and gender and analyzed for organochlorine chemical residues and elemental contaminants using instrumental methods, and for 2,3,7,8-tetrachloro dibenzo-p-dioxin-like activity (TCDD-EQ) using the H4IIE rat hepatoma cell bioassay. Overall, fish from lower RGB stations contained greater concentrations of organochlorine pesticide residues and appeared to be less healthy than those from sites in the central and upper parts of the basin, as indicated by a general gradient of residue concentrations and biomarker responses. A minimal number of altered biomarkers and few or no elevated contaminant concentrations were noted in fish from the upper RGB. The exception was elevated concentrations [up to 0.46 Ag/g wet-weight (ww)] of total mercury (Hg) in predatory species from the Rio Grande at Elephant Butte Reservoir, NM, a condition documented in previous studies. Arsenic (As) and selenium (Se) concentrations were greatest in fish from sites in the central RGB; Se concentrations in fish from the Pecos River at Red Bluff Lake, TX and from the Rio Grande at Langtry, TX and Amistad International Reservoir, TX exceeded published fish and wildlife toxicity thresholds. In the lower RGB, residues of This article is a U.S. government work, and is not subject to copyright in the United States.p,pV-DDT metabolites (V1.69 Ag/g ww), chlordane-related compounds (V0.21 Ag/g ww), dieldrin (V0.0.05 Ag/g ww), and toxaphene (V2.4 Ag/g ww) were detected in fish from most sites; maximum concentrations were in channel catfish (Ictalurus punctatus) from the Arroyo Colorado at Harlingen, TX. Concentrations of one or more residues exceeded toxicity thresholds for fish and wildlife in fish from this site and from the Rio Grande at Mission, TX and Brownsville, TX; however, concentrations were lower than those reported by previous studies. In addition, the proportional concentrations of p,pV-DDT at all sites were low, indicating weathered DDT rather than the influx of new ma...

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“…In some portions of the drainage, Hg concentrations in river sediments are relatively high (>50 mg/kg) and are temporally increasing [14,15]. In addition, several wildlife species associated with the river are contaminated with Hg [16]. Several surveys of fish in the Lower Rio Grande drainage found that many piscivorous fish exceed U.S. Environmental Protection Agency (EPA) benchmarks designed to protect human and wildlife health [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Mercury contamination of the fish community of a semi‐arid and arid river system: Spatial variation and the influence of environmental gradients

Smith

Abuzeineh

Chumchal

et al. 2010

Enviro Toxic and Chemistry

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Mercury (Hg) contamination of aquatic ecosystems is a global environmental problem. Data are abundant on Hg contamination and factors that affect its bioaccumulation in lake communities, but comparatively little information on riverine ecosystems exists. The present study examines fish Hg concentrations of the Lower Rio Grande/Rio Bravo del Norte drainage, Texas, USA and several of its major tributaries in order to assess whether spatial variation occurs in fish Hg concentrations in the drainage and if patterns of Hg contamination of fish are related to gradients in environmental factors thought to affect Hg concentrations in fish communities. Fish, invertebrates, sediments, and water quality parameters were sampled at 12 sites along the lower Rio Grande/Rio Bravo del Norte drainage multiple times over a one-year period. Spatial variation was significant in fish Hg concentrations when fish were grouped by literature-defined trophic guilds or as stable isotope-defined trophic levels, with highest concentrations found in the Big Bend region of the drainage. Mercury in fish in most trophic guilds and trophic levels were positively related to environmental factors thought to affect Hg in fish, including water column dissolved organic carbon (DOC) and sediment Hg concentrations. It is likely that fish Hg concentrations in the Big Bend region are relatively high because this section of the river has abundant geologic Hg sources and environmental conditions which may make it sensitive to Hg inputs (i.e., high DOC, variable water levels). Results from the present study indicate that Hg contamination of the Rio Grande/Rio Bravo del Norte has substantial implications for management and protection of native small-bodied obligate riverine fish, many of which are imperiled.

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Environmental contaminants in prey and tissues of the peregrine falcon in the Big Bend Region, Texas, USA

Cited by 31 publications

References 7 publications

Toxic effects of dietary methylmercury on immune function and hematology in American kestrels (Falco sparverius)

Toxic effects of dietary methylmercury on immune function and hematology in American kestrels (Falco sparverius)

Environmental contaminants and biomarker responses in fish from the Rio Grande and its U.S. tributaries: Spatial and temporal trends

Mercury contamination of the fish community of a semi‐arid and arid river system: Spatial variation and the influence of environmental gradients

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