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Trace Element Concentrations and Bioindicator Responses in Tree Swallows from Northwestern Minnesota 总被引:5,自引:0,他引:5
Custer CM Custer TW Warburton D Hoffman DJ Bickham JW Matson CW 《Environmental monitoring and assessment》2006,118(1-3):247-266
Extremely high concentrations of cadmium (3.5 μg/g dry wgt.) and elevated concentrations of chromium (>10 μg/g dry wgt.) and mercury (1.6 μg/g dry wgt.) were reported in waterbird tissues at Agassiz National Wildlife Refuge in northwestern Minnesota in 1994. Tree
swallows (Tachycineta bicolor) were studied during 1998–2001 at three drainages into the Refuge, two pools on the Refuge, and at a nearby reference location
to document whether high levels of contaminants were still present, and if so to quantify the source and severity of the contamination.
Trace elements were measured in tree swallow eggs, livers, and diet. Reproductive success and bioindicator responses were
monitored. In 2000, water was drawn down on Agassiz Pool, one of the main pools on the Refuge. This presented an opportunity
to evaluate the response of trace element concentrations in the diet and tissues of tree swallows after reflooding. High concentrations
of trace elements were not detected in swallow tissues, nor were there differences among locations. Less than 20% of swallow
samples had detectable concentrations of cadmium or chromium. Mercury concentrations were low and averaged <0.25 μg/g dry wgt. in swallow tissues. Trace elements, including mercury, did not increase in tree swallows following the 2000 drawdown
at Agassiz Pool. Hatching success and survival of nestlings to 12 days-of-age for tree swallows on the Refuge were similar
to the national average and consistent with background trace element concentrations. Bioindicator measurements were within
the normal ranges as well. 相似文献
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Custer TW Custer CM Goatcher BL Melancon MJ Matson CW Bickham JW 《Environmental monitoring and assessment》2006,121(1-3):541-558
Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d′Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d′Inde (2.8 μ g/g PCBs in eggs and 1.5 μ g/g PCBs in nestlings) than at the other two sites (< 0.2 μ g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d′Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites. 相似文献
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Kenow KP Hoffman DJ Hines RK Meyer MW Bickham JW Matson CW Stebbins KR Montagna P Elfessi A 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):732-738
We quantified the level of dietary mercury (Hg), delivered as methylmercury chloride (CH3HgCl), associated with negative effects on organ and plasma biochemistries related to glutathione (GSH) metabolism and oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks reared from hatch to 105 days. Mercury-associated effects related to oxidative stress and altered glutathione metabolism occurred at 1.2 μg Hg/g and 0.4 μg Hg/g, an ecologically relevant dietary mercury level, but not at 0.08 μg Hg/g. Among the variables that contributed most to dissimilarities in tissue chemistries between control and treatment groups were increased levels of oxidized glutathione (GSSG), GSH peroxidase, and the ratio of GSSG to GSH in brain tissue; increased levels of hepatic GSH; and decreased levels of hepatic glucose-6-phosphate dehydrogenase (G-6-PDH). Our results also suggest that chronic exposure to environmentally relevant dietary Hg levels did not result in statistically significant somatic chromosomal damage in common loon chicks. 相似文献
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Jie Zhuang Randall W. Gentry Gui-Rui Yu Gary S. Sayler John W. Bickham 《Environmental management》2010,46(4):525-530
The sustainability implications of bioenergy development strategies are large and complex. Unlike conventional agriculture,
bioenergy production provides an opportunity to design systems for improving eco-environmental services. Different places
have different goals and solutions for bioenergy development, but they all should adhere to the sustainability requirements
of the environment, economy, and society. This article serves as a brief overview of China’s bioenergy development and as
an introduction to this special issue on the impacts of bioenergy development in China. The eleven articles in this special
issue present a range of perspectives and scenario analyses on bioenergy production and its impacts as well as potential barriers
to its development. Five general themes are covered: status and goals, biomass resources, energy plants, environmental impacts,
and economic and social impacts. The potential for bioenergy production in China is huge, particularly in the central north
and northwest. China plans to develop a bioenergy capacity of 30GW by 2020. However, realization of this goal will require
breakthroughs in bioenergy landscape design, energy plant biotechnology, legislation, incentive policy, and conversion facilities.
Our analyses suggest that (1) the linkage between bioenergy, environment, and economy are often circular rather than linear
in nature; (2) sustainability is a core concept in bioenergy design and the ultimate goal of bioenergy development; and (3)
each bioenergy development scheme must be region-specific and designed to solve local environmental and agricultural problems. 相似文献
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Custer TW Dummer PM Custer CM Li AU Warburton D Melancon MJ Hoffman DJ Matson CW Bickham JW 《Environmental monitoring and assessment》2007,133(1-3):335-345
The U.S. Army Corps of Engineers conducted a water drawdown on Navigation Pool 8 of the Upper Mississippi River during the
summers of 2001 and 2002 to increase aquatic vegetation production and thereby improve fish and wildlife habitat. Flooding
of previously dried wetlands, however, may increase the rate of mercury methylation and make mercury more available to terrestrial
vertebrates that feed in aquatic environments. Our objective was to determine if mercury, other elements, and organochlorine
contaminants were more available to vertebrates following the 2001 drawdown. Tree swallow (Tachycineta bicolor) eggs and nestlings were collected at two sites on Pool 8 and a nearby Reference site in 2000 (pre-2001 drawdown), 2001 (pre-2001
drawdown) and 2002 (post-2001 drawdown) and tissues were analyzed for mercury, other elements, and organochlorine contaminants.
Bioindicator measurements of genetic damage, oxidative stress, ethoxyresorufin-O-dealkylase activity, and the ratio of liver to nestling mass were also measured in nestlings at all sites and all years.
Based on a multivariate analysis, the 2001 drawdown of Pool 8 did not influence element concentrations, organochlorine concentrations,
or bioindicator response. Concentrations of inorganic and organochlorine contaminants in tree swallow eggs and nestlings were
not at toxic levels. Hatching success did not differ among years and was comparable to the nationwide average. 相似文献
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