Geology topics

C. W. Matson

Publications and source records attributed to C. W. Matson.

10 recordsLinked to original sources

USGS2008

Potential effects of environmental contaminants on P450 aromatase activity and DNA damage in swallows from the Rio Grande and Somerville, Texas

Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies. ?? 2008 Springer Science+Business Media, LLC.

Ecotoxicology↗

USGS2008

Effects of methylmercury exposure on glutathione metabolism, oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks

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 :g Hg/g and 0.4 :g Hg/g, an ecologically relevant dietary mercury level, but not at 0.08 :g 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. Oxidative stress and altered glutathione metabolism were evident in common loon chicks exposed to >0.4 :g Hg as CH3HgCl per gram wet food intake.

Environmental Pollution↗

USGS2007

Contaminant exposure and biomarker response in embryos of Black-crowned Night-herons (Nycticorax nycticorax) nesting near Lake Calumet, Illinois

We examined a suite of environmental contaminants and exposure endpoints in black-crowned night-heron ( Nycticorax nycticorax , BCNH) embryos collected in 2002 from colonies in Illinois, Minnesota, and Virginia. Embryos from the Lake Calumet, IL, colony had greater exposure to polychlorinated biphenyls (PCBs), 4,4'-dichlorodiphenyldichloroethylene (DDE), dieldrin, transnonachlor, oxychlordane, cobalt, copper, and selenium than did those from northwest MN and coastal VA. Embryos from IL and VA contained greater concentrations of mercury and zinc than those from MN, whereas the latter had greater accumulation of lead. Greater exposure of IL embryos to PCBs was reflected in greater ethoxyresorufin-O-deethylase and benzyloxyresorufin-O-dealkylase induction. However, measures of oxidative stress and genotoxicity were similar to those in embryos from the other colonies examined, and no overt toxic effects of contaminant exposure such as embryo mortality or malformations were observed. Although efforts to clean up the south Chicago environment are ongoing, Lake Calumet BCNH, and undoubtedly other piscivorous wildlife foraging in the region, continue to be exposed to a variety of environmental contaminants. Life-history characteristics of this species make it ideal as an environmental sentinel for the success of the cleanup of the south Chicago environment.

Illinois↗

USGS2007

Water level management and contaminant exposure to tree swallows nesting on the Upper Mississippi River

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.

Environmental Monitoring and Assessment↗

USGS2006

Contaminant exposure of barn swallows nesting on Bayou d'Inde, Calcasieu Estuary, Louisiana, USA.

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 micro g/g PCBs in eggs and 1.5 micro g/g PCBs in nestlings) than at the other two sites (< 0.2 micro 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.

Environmental Monitoring and Assessment↗

USGS2006

Biomarkers of exposure and effects of environmental contaminants on swallows nesting along the Rio Grande, Texas, USA

We collected adult cave swallows (Petrochelidon fulva) and cliff swallows (P. pyrrhonota) during the breeding seasons in 1999 and 2000 from eight locations along the Rio Grande from Brownsville to El Paso (unless otherwise specified, all locations are Texas, USA) and an out-of-basin reference location. Body mass, spleen mass, hepatosomatic index (HSI), gonadosomatic index (GSI), thyroxine (T4) in plasma, DNA damage measured as the half-peak coefficient of variation of DNA content (HPCV) in blood cells, as well as acetylcholinesterase and butyrylcholinesterase in brain were compared with concentrations of organochlorines, metals, and metalloids in carcasses to determine potential effects of contaminants on swallows during the breeding season. Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p???-DDE) were significantly greater in swallows from El Paso than in those from most locations, except for Pharr and Llano Grande. All swallows from these three locations had p,p???-DDE concentrations of 3 ??g/g wet weight or greater. Swallows from El Paso either had or shared the highest concentrations of p,p???-DDE, polychlorinated biphenyls, and 13 inorganic elements. Swallows from El Paso exhibited greater spleen mass and HPCV values as well as lower T4 values compared with those from other locations. Thyroxine was a potential biomarker of contaminant exposure in swallows of the Rio Grande, because it was negatively correlated with p,p???-DDE and Se. Spleen mass was positively correlated with selenium and HSI and negatively correlated with body mass, GSI, Mn, and Ni. Overall, the present study suggests that insectivorous birds living in areas of high agricultural and industrial activity along the Rio Grande bioaccumulate environmental contaminants. These contaminants, particularly p,p???-DDE, may be among multiple factors that impact endocrine and hematopoietic function in Rio Grande swallows. ?? 2006 SETAC.

Environmental Toxicology and Chemistry↗

USGS2006

Trace element concentrations and bioindicator responses in tree swallows from northwestern Minnesota

Extremely high concentrations of cadmium (3.5 μ g/g dry wgt.) and elevated concentrations of chromium (>10 μ g/g dry wgt.) and mercury (1.6 μ g/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 μ g/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.

Minnesota↗

USGS2005

Effects of contaminant exposure on reproductive success of ospreys (Pandion haliaetus) nesting in Delaware River and Bay, USA

Despite serious water-quality problems and pollutant loading and retention, Delaware River and Bay(USA) provide important wildlife habitat. In 2002, we conducted a comprehensive evaluation of contaminant exposure and reproduction of ospreys ( Pandion haliaetus ) breeding in Delaware River and Bay. Sample eggs were collected from 39 nests and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury; a subset of 15 eggs was analyzed for perfluorinated compounds and polybrominated diphenyl ethers (PBDEs). The fate of each nest was monitored weekly. Concentrations of 10 organochlorine pesticides or metabolites, total PCBs, and several toxic PCB congeners were greater ( p < 0.05) in eggs collected between the Chesapeake and Delaware Canal (C and D Canal) and Trenton (Delaware River and northern Bay) compared to other sites. Concentrations of p,p ′-dichlorodiphenyldichloroethylene ( p,p ′-DDE; 0.785–3.84 μg/g wet wt) and total PCBs (5.50–14.5 μg/g wet wt) in eggs collected between the C and D Canal and Trenton were similar to levels recently found in the Chesapeake Bay. In all study segments, at least one young fledged from 66 to 75% of nests. Productivity for Delaware Inland Bays (reference area) and southern Delaware Bay was 1.17 and 1.42 fledglings/active nest, respectively; north of the C and D Canal, productivity was 1.00 fledgling/active nest, which is marginally adequate to maintain the population. Using these data, a logistic regression model found that contaminant concentrations ( p,p ′-DDE, heptachlor epoxide, chlordane and metabolites, and total PCBs) were predictive of hatching success. Several perfluorinated compounds and PBDEs were detected in eggs at concentrations approaching 1 μg/g wet weight. These findings provide evidence that contaminants continue to be a significant stressor on osprey productivity in the northern Delaware River and Bay.

Delaware, New Jersey, Pennsylvania,↗

USGS2005

Exposure and effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River, Rhode Island, USA

Concentrations of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) in tree swallows ( Tachycineta bicolor ) nesting along the Woonasquatucket River northwest of Providence (RI, USA) in 2000 and 2001 were some of the highest ever reported in avian tissues. Mean concentrations in eggs ranged from 300 to > 1,000 pg/g wet weight at the two most contaminated ponds, Allendale and Lyman. Mean egg concentrations at Greystone, the upstream reference pond, were 12 and 29 pg/g. Positive accumulation rates and concentrations in diet samples from 12-day-old nestlings indicated that the contamination was accumulated locally. Concentrations in diet of between 71 and 219 pg/g wet weight were more than 6 and 18 times higher than concentrations considered safe for birds (10–12 pg/g). Hatching success was negatively associated with concentration of TCDD in eggs. Only about half the eggs hatched at Allendale compared with >77% at Greystone. The national average for hatching success in successful nests is 85%. No other contaminants, such as polychlorinated biphenyls and mercury, were present in any sample at concentrations known to affect avian reproduction. Three bioindicators, half-peak coefficient of geometric variation, ethoxyresorufin- O -dealkylase activity, and brain asymmetry were assessed relative to TCDD contamination.

Rhode Island↗

USGS2004

Evidence of chromosomal damage in common eiders (Somateria mollissima) from the Baltic Sea

Common eiders nesting in the Baltic Sea are exposed to generally high levels of contaminants including potentially genotoxic polycyclic aromatic hydrocarbons and organochlorines. Blood samples were collected from eiders at eight sites in the Baltic Sea and two sites in the Beaufort Sea. DNA content variation was estimated using the flow cytometric method, and subsequently utilized as a biomarker of genetic damage. We observed no significant differences in genetic damage among populations within either the Baltic or Beaufort Seas. However, eider populations from the Baltic Sea had significantly elevated estimates of genetic damage compared to populations from the Beaufort Sea.

Baltic Sea, Beaufort Seas↗