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At least 1,621 records · Page 90Linked to original sources

Effects of Phos-Chek G75-F and Silv-Ex on developing Northern Bobwhite Quail (Colinus virginianus)

Eggs of nesting birds situated in peripheral areas serving as fire breaks are at risk of being sprayed with fire control chemicals. Acute toxicity tests were conducted by immersing northern bobwhite quail eggs for 10 s in different water-based concentrations of Silv-Ex® (SE), a foam-suppressant chemical, and Phos-Chek® G75-F (PC), a fire retardant chemical, on day 4 or day 11 of incubation. An attempt was made to relate the treatment concentrations to the actual field application levels. Mortality appeared higher in most groups exposed on day 11 than on day 4, suggesting that on day 11 the extensive chorioallantoic vascular network permitted greater uptake of chemical. Only 24–60% of the embryos survived to hatch at exposure concentrations of 202, 269, and 454 g/L PC when treated on incubation day 11. At higher concentrations including 681, 956, and 1,211 g/L PC, the compound did not completely dissolve in water and clumped on eggshells, resulting in greater hatching success. Exposures to SE at 100 g/L on incubation day 11 did not significantly affect hatching success of embryos but did significantly reduce the percent hematocrit in blood compared with controls. Incubation day 11 exposure to 202 and 1,211 g/L PC led to a significant increase in plasma aspartate aminotransferase, and day 4 exposure to 1,211 g/L PC resulted in a significant increase in alanine aminotransferase. In addition to elevated liver enzymes, these treatments resulted in a decrease in the number of hepatocyte profiles (1,211 g/L PC at day 4 and day 11) and an increase in hepatocyte size (202 and 1,211 g/L PC at day 11) in hatchlings. A combination of SE and PC was synergistic (202 g/L PC and 50 g/L SE) at day 11 of incubation with respect to decreased hatching success and reduced bone lengths. However, lower concentrations of SE (10 g/L or 30 g/L) combined with 202 g/L of PC appeared antagonistic. This may be due to SE, as a surfactant, altering the ability of PC to penetrate the egg. Our results show fewer adverse effects following exposure to SE than to PC; therefore application of SE may be less harmful to breeding bird populations.

Archives of Environmental Contamination and Toxico↗

Phosphorus amendment reduces bioavailability of lead to mallards ingesting contaminated sediments

Lead poisoning of waterfowl has been reported for decades in the Coeur d'Alene River Basin in Idaho as a result of the ingestion of lead-contaminated sediments. We conducted a study to determine whether the addition of phosphoric acid to sediments would reduce the bioavailability of lead to mallards ( Anas platyrhynchos ). When sediments were amended with 1% phosphorus under laboratory conditions, and diets containing 12% amended sediment were fed to mallards, reductions in tissue lead were 43% in blood, 41% in liver, and 59% in kidney with sediment containing about 4,520 μg/g lead on a dry-weight basis and 41, 30, and 57% with sediment containing about 6,990 μg/g lead. When sediments were treated with phosphorus and left to age for about 5 months in the field, reductions in lead were 56% in blood, 54% in liver, and 66% in kidney at one site with about 5,390 μg/g lead and 64, 57, and 77% at a second site with about 6,990 μg/g lead. In the field, the inability to mix the phosphoric acid uniformly and deeply enough into the sediment may have resulted in more than 1% phosphorus being added to the sediment. Although both lab and field amendments of phosphorus substantially reduced the bioavailability of lead, lead concentrations in the tissues of mallards fed the amended sediments were still above those believed to be harmful to waterfowl. Based on earlier studies of sediment toxicity to waterfowl in the Coeur d'Alene River Basin, combined with the results of our amendment study, the addition of phosphoric acid as we used it might only significantly benefit waterfowl where sediments or soils contain less than 1,000-2,000 μg/g lead.

Idaho↗

Zinc and lead poisoning in wild birds in the Tri-State Mining District (Oklahoma, Kansas, Missouri)

contaminated with Pb, Cd, and Zn from mining, milling and smelting. Metals have been dispersed heterogeneously throughout the District in the form of milled mine waste ('chat'), as flotation tailings and from smelters as aerial deposition or slag. This study was conducted to determine if the habitat has been contaminated to the extent that the assessment populations of wild birds are exposed to toxic concentrations of metals. American robins (Turdus migratorius), northern cardinals (Cardinalis cardinalis), and waterfowl had increased Pb tissue concentrations (p < 0.05) compared with Pb tissue concentrations from reference birds, and the exposure of songbirds to Pb was comparable with that of birds observed at other sites severely contaminated with Pb. Mean activities of the Pb-sensitive enzyme delta-aminolevulinic acid dehydratase (ALAD) were decreased by >50% in red blood cells in these birds (p < 0.05). Several birds had tissue concentrations of Pb that have been associated with impaired biological functions and external signs of poisoning. Cadmium was increased in kidneys of songbirds (p < 0.05), but no proximal tubule cell necrosis associated with Cd poisoning was observed. Zinc concentrations in liver and kidney of waterfowl were significantly higher (p < 0.05) than reference values. The increased environmental concentrations of Zn associated with mining in the District accounted for the pancreatitis previously observed in five waterfowl from the District. The District is the first site at which free-flying wild birds have been found to be suffering severe effects of Zn poisoning.

Kansas, Missouri, Oklahoma↗

Concentrations of metals in water, sediment, biofilm, benthic macroinvertebrates, and fish in the Boulder River watershed, Montana, and the role of colloids in metal uptake

To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs ), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 μg/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 μg/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for Pb into biological components seems to begin with sediment because concentrations of Pb in water were not significantly correlated with any other component and because concentrations of Pb in the water were often below detection limits.

Montana↗

Selenium and metal concentrations in waterbird eggs and chicks at Agassiz National Wildlife Refuge, Minnesota

Exceptionally high cadmium (Cd) and chromium (Cr) concentrations were reported in eggs, feathers, or livers of selected waterbird species nesting at Agassiz National Wildlife Refuge (Agassiz) in 1994. Ten- to 15-day-old Franklin's gull (Larus pipixcan), black-crowned night-heron (Nycticorax nycticorax), and eared grebe (Podiceps nigricollis) chicks were collected in 1998, 1999, and 2001 at Agassiz and analyzed for selenium (Se) and metals including Cd and Cr. Freshly laid eggs were collected in 2001 from Franklin's gull, black-crowned night-heron, eared grebe, and pied-billed grebe (Podilymbus podiceps) nests at Agassiz. Based on a multivariate analysis, the pattern of Se and metal concentrations differed among species for eggs, chick feathers, and chick livers. Low Cd and Cr concentrations were measured in eggs, chick livers, and chick feathers of all four species. Mercury concentrations in black-crowned night-heron and eared grebe eggs collected from Agassiz in 2001 were lower than concentrations reported in 1994. Se and metal concentrations, including Cd and Cr, in waterbird eggs and chicks collected at Agassiz in 1998, 1999, and 2001 were not at toxic levels. ?? 2007 Springer Science+Business Media, LLC.

Archives of Environmental Contamination and Toxico↗

Concentrations of metals in blood and feathers of nestling ospreys (Pandion haliaetus) in Chesapeake and Delaware Bays

In 2000, 2001, and 2002, blood and feather samples were collected from 40–45-day-old nestling ospreys ( Pandion haliaetus ) from Chesapeake Bay and Delaware Bay and River. Concentrations of 18 metals, metalloids, and other elements were determined in these samples by inductively coupled plasma-mass spectroscopy, and Hg concentrations were measured by cold vapor atomic absorption spectroscopy. When compared to concurrent reference areas (South, West, and Rhode Rivers), mean As and Hg concentrations in blood were greater ( p < 0.05) in two of three Chesapeake Bay regions of concern (Baltimore Harbor [As: 1.18 vs. 0.548 μg/g dw], Anacostia River [Hg: 0.305 vs. 0.178 μg/g dw], and Elizabeth River [As: 0.876 vs. 0.663 μg/g dw; Hg: 0.260 vs. 0.180 μg/g dw]). Lead was detected more frequently in blood of nestlings from the highly industrialized Elizabeth River compared to the rural reference area. When compared to the concurrent reference area, mean Al, Ba, Hg, Mn, and Pb concentrations in feathers were substantially greater ( p < 0.05) in one or more Chesapeake regions of concern (Anacostia River [Al: 206 vs. 62.1 μg/g dw; Ba: 3.31 vs. 0.823 μg/g dw; Mn: 65.4 vs. 22.9 μg/g dw] and Elizabeth River [Al: 165 vs. 63.5 μg/g dw; Hg: 1.24 vs. 0.599 μg/g dw; Pb 1.47 vs. 0.543 μg/g dw]). When compared to the coastal Inland Bays reference area, feathers of nestlings from northern Delaware Bay and River had greater concentrations ( p < 0.05) of Ba (1.90 vs. 0.660 μg/g dw), Fe (258 vs. 109 μg/g dw), Mn (18.5 vs. 4.66 μg/g dw), Mo (0.130 vs. 0.040 μg/g dw), Pb (1.96 vs. 0.624 μg/g dw), and V (0.671 vs. 0.325 μg/g dw), presumably due to extensive metal-working and petroleum refinery activities. Concentrations of Hg in nestling feathers from Delaware were frequently greater than in the Chesapeake. The present findings and those of related reproductive studies suggest that concentrations of several heavy metals (e.g., Cd, Hg, Pb) in nestling blood and feathers from Chesapeake and Delaware Bays were below toxicity thresholds and do not seem to be affecting chick survival during the nestling period.

Delaware, Maryland, New Jersey, Virginia↗

Distribution of pesticides, PAHs, PCBs, and bioavailable metals in depositional sediments of the lower Missouri River, USA

The lower Missouri River was studied to determine the distribution of selected persistent organic pollutants and bioavailable metals in depositional sediments. Nineteen sites between Omaha, Nebraska and Jefferson City, Missouri were sampled. This stretch of the river receives point-source and non-point-source inputs from industrial, urban, and agricultural activities. As part of an ecological assessment of the river, concentrations of 29 legacy organochlorine pesticides (OC pesticides), including chlordanes, DDTs, and hexachlorocyclohexanes; a select list of current-use pesticides, including trifluralin, diazinon, chlorpyrifos, and permethrin, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), divalent metals (copper, nickel, zinc, cadmium, and lead), and polybrominated diphenyl ethers (PBDEs) were determined. Concentrations (dry weight basis) of OC pesticides in the sediments were less than 1 ng/g, with the exception of the backwater sediment collected from the mouth of the Blue River in the Kansas City metropolitan area, which contained up to 20 ng/g total chlordane, 8.1 ng/g p,p???-DDE, 1.5 ng/g lindane, 4.8 ng/g dieldrin, and 3 ng/g endrin. Concentrations of chlorpyrifos and permethrin ranged from less than 1 ng/g to 5.5 ng/g and 44 ng/g, respectively. Concentrations of PCBs ranged from less than 11 ng/g to 250 ng/g, with the Blue River and Sibley sediments containing 100 and 250 ng/g total PCBs, respectively. Concentrations of total PAHs at 17 of the 19 sites ranged from 250 to 700 ng/g, whereas the Riverfront and Blue River sites in Kansas City contained 1100 ng/g and nearly 4000 ng/g, respectively. Concentrations of the metals did not vary significantly among most sites; however, the Blue River site contained elevated concentrations of zinc (104 ??g/g), cadmium (0.7 ??g/g), and lead (34 ??g/g) compared to the other sites. The moderately high concentrations of acid-volatile sulfide in the sediments suggest a low potential for metal toxicity to benthic organisms along this reach of the Missouri River. The depositional area sediments contained concentrations of the targeted persistent organic chemicals and metals that were below published probable effect level concentrations. ?? 2008 Springer Science+Business Media, LLC.

Archives of Environmental Contamination and Toxico↗

Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus)

Amphibians in terrestrial environments obtain water through a highly vascularized pelvic patch of skin. Chemicals can also be exchanged across this patch. Atrazine (ATZ), a widespread herbicide, continues to be a concern among amphibian ecologists based on potential exposure and toxicity. Few studies have examined its impact on the terrestrial juvenile or adult stages of toads. In the current study, we asked the following questions: (1) Will juvenile American toads ( Bufo americanus ) avoid soils contaminated with ATZ? (2) Can they absorb ATZ across the pelvic patch? (3) If so, how is it distributed among the organs and eventually eliminated? We conducted a behavioral choice test between control soil and soil dosed with ecologically relevant concentrations of ATZ. In addition, we examined the uptake, distribution, and elimination of water dosed with 14 C-labeled ATZ. Our data demonstrate that toads do not avoid ATZ-laden soils. ATZ crossed the pelvic patch rapidly and reached an apparent equilibrium within 5 h. The majority of the radiolabeled ATZ ended up in the intestines, whereas the greatest concentrations were observed in the gall bladder. Thus, exposure of adult life stages of amphibians through direct uptake of ATZ from soils and runoff water should be considered in risk evaluations.

Archives of Environmental Contamination and Toxico↗

Contaminants in stream sediments from seven United States metropolitan areas: part I: distribution in relation to urbanization

Organic contaminants and trace elements were measured in bed sediments collected from streams in seven metropolitan study areas across the United States to assess concentrations in relation to urbanization. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, the pyrethroid insecticide bifenthrin, and several trace elements were significantly related to urbanization across study areas. Most contaminants (except bifenthrin, chromium, nickel) were significantly related to the total organic carbon (TOC) content of the sediments. Regression models explained 45–80 % of the variability in individual contaminant concentrations using degree of urbanization, sediment-TOC, and study-area indicator variables (which represent the combined influence of unknown factors, such as chemical use or release, that are not captured by available explanatory variables). The significance of one or more study-area indicator variables in all models indicates marked differences in contaminant levels among some study areas, even after accounting for the nationally modeled effects of urbanization and sediment-TOC. Mean probable effect concentration quotients (PECQs) were significantly related to urbanization. Trace elements were the major contributors to mean PECQs at undeveloped sites, whereas organic contaminants, especially bifenthrin, were the major contributors at highly urban sites. Pyrethroids, where detected, accounted for the largest share of the mean PECQ. Part 2 of this series (Kemble et al. 2012) evaluates sediment toxicity to amphipods and midge in relation to sediment chemistry.

Archives of Environmental Contamination and Toxico↗

Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.

Idaho↗

Effects of age, colony, and sex on mercury concentrations in California sea lions

We measured total mercury (THg) concentrations in California sea lions ( Zalophus californianus ) and examined how concentrations varied with age class, colony, and sex. Because Hg exposure is primarily via diet, we used nitrogen ( &delta; 15 N) and carbon ( &delta; 13 C) stable isotopes to determine if intraspecific differences in THg concentrations could be explained by feeding ecology. Blood and hair were collected from 21 adult females and 57 juveniles from three colonies in central and southern California (San Nicolas, San Miguel, and A&ntilde;o Nuevo Islands). Total Hg concentrations ranged from 0.01 to 0.31 &mu;g g &minus;1 wet weight (ww) in blood and 0.74 to 21.00 &mu;g g &minus;1 dry weight (dw) in hair. Adult females had greater mean THg concentrations than juveniles in blood (0.15 vs. 0.03 &mu;g &minus;1 ww) and hair (10.10 vs. 3.25 &mu;g &minus;1 dw). Age class differences in THg concentrations did not appear to be driven by trophic level or habitat type because there were no differences in &delta; 15 N or &delta; 13 C values between adults and juveniles. Total Hg concentrations in adult females were 54 % (blood) and 24 % (hair) greater in females from San Miguel than females from San Nicolas Island, which may have been because sea lions from the two islands foraged in different areas. For juveniles, we detected some differences in THg concentrations with colony and sex, although these were likely due to sampling effects and not ecological differences. Overall, THg concentrations in California sea lions were within the range documented for other marine mammals and were generally below toxicity benchmarks for fish-eating wildlife.

Archives of Environmental Contamination and Toxico↗

Evaluation of polymer-based dust palliatives in soil and stormwater runoff in an arid environment

Dust palliatives are used to reduce fugitive dust in areas susceptible to erosion by wind and rain. In 2015, the Bureau of Land Management (BLM) temporarily approved the use of polymer-based dust palliatives during the construction and operation of a solar energy facility and, in 2019, on a mining access road in Clark County, Nevada. The areas treated with palliative are habitat to the desert tortoise. The desert tortoise consumes water opportunistically from puddles, saturated soils, or by the collection of precipitation on their carapaces. Since little is known about the toxicity of polymeric substances to the desert tortoise, the BLM is concerned with the exposure of the desert tortoise to palliative in stormwater runoff. The BLM collaborated with the US Geological Survey (USGS) to evaluate the transport of butyl acrylate vinyl acetate (BA-VA), the copolymer ingredient in the dust palliatives applied in the study, away from areas of application. BA-VA concentrations were measured in soils treated with palliative up to 90 days post-treatment, after which the copolymer became undetectable (< 0.55 mg/g). BA-VA concentrations in all stormwater samples within and outside treated areas were consistently below detection (< 0.20 mg/mL). Although stormwater and treated soils eroded from the solar facility application area were found to have BA-VA concentrations below detection (< 0.55 mg/g), it is likely that some BA-VA (parent or degradation product) was transported with suspended material. It is also likely that the amount of BA-VA transported away from areas of application was a small fraction of that applied.

Nevada↗

Behavioral dysfunctions correlate to altered physiology in rainbow trout (Oncorynchus mykiss) exposed to cholinesterase-inhibiting chemicals

We selected four metrics of swimming behavior (distance swam, speed, rate of turning, and tortuosity of path) and the commonly used biochemical marker, brain cholinesterase (ChE) activity, to assess (1) the sensitivity and reliability of behavior as a potential biomarker in monitoring work, (2) the potential for these endpoints to be used in automated monitoring, and (3) the linkage between behavior and its underlying biochemistry. Malathion-exposed fish exhibited large decreases in distance and speed and swam in a more linear path than control fish after 24 h exposure. By 96 h exposure, fish still swam slower and traveled less distance; fish fully recovered after 48 h in clean water. Diazinon-exposed fish exhibited decreases in distance, speed, and turning rate compared to controls. After 48 h recovery in clean water, fish exposed to diazinon had not recovered to control levels. The behavioral responses provided measures of neurotoxicity that were easily quantifiable by automated means, implying that the inclusion of behavior in monitoring programs can be successful. Furthermore, correlations between behavior and biochemical endpoints, such as ChE inhibition, suggest that this approach can provide a meaningful link between biochemistry and behavior and can provide useful information on toxicant impacts.

Archives of Environmental Contamination and Toxico↗

Organochlorine contaminants and biomarker response in double-crested cormorants nesting in Green Bay and Lake Michigan, Wisconsin, USA

Double-crested cormorant ( Phalacrocorax auritus ) eggs at pipping and sibling 10-day-old chicks were collected from two colonies in Green Bay, WI, one colony in Lake Michigan, WI, and reference colonies in South Dakota and Minnesota. Egg contents and chicks were analyzed for organochlorine contaminants including polychlorinated biphenyl (PCB) congeners. Livers of embryos and chicks were assayed for hepatic microsomal ethoxyresorufin- O -dealkylase (EROD) activity. Eggshell thickness and the physical dimensions of embryo brains were measured. Concentrations of organochlorines, including p,p′-DDE (p,p′-dichlorodiphenyldichloroethylene), PCBs, and PCB congeners were generally an order of magnitude higher in eggs and chicks from Wisconsin than from reference locations. Total PCBs averaged 10–13 μg/g wet weight in eggs from three Wisconsin colonies compared to 0.9 μg/g PCBs from reference locations. Double-crested cormorant chicks accumulated on average 33–66 μg PCBs/day and 7–12 μg p,p′-DDE/day in the Wisconsin colonies compared to 0 μg PCBs/day and 1 μg p,p′-DDE/day in the reference colonies. At pipping, EROD activity in the livers of cormorant embryos was significantly higher in the Wisconsin colonies and significantly correlated with PCBs and the toxic equivalents (TEQs) of aryl hydrocarbon-active PCB congeners relative to 2,3,7,8-tetrachlorodibenzo- p -dioxin. However, in 10-day-old chicks EROD activity was not consistently different among colonies and was not correlated with PCBs or TEQs. A significant negative relationship between embryo brain asymmetry and the size of the egg suggested that physical constraint might be an important factor influencing the response of this bioindicator. Thinner eggshells in two colonies located near Door County, Wisconsin, suggested that historic p,p′-DDE residues associated with orchards are still an important source of p,p′-DDE in the local environment.

Minnesota, South Dakota, Wisconsin↗

Organochlorine contaminant exposure and reproductive success of Black-Crowned Night Herons (Nycticorax nycticorax) nesting in Baltimore Harbor, Maryland

The declining size of the Baltimore Harbor black-crowned night-heron ( Nycticorax nycticorax ) colony has been hypothesized to be linked to polychlorinated biphenyl (PCB) exposure. In 1998, a “sample egg” was collected from 65 black-crowned night-heron nests (each containing ≥ three eggs) for contaminant analysis, and the remaining eggs in these 65 nests, plus four two-egg nests, were monitored for hatching and fledging success. Eggs were also collected from 12 nests at Holland Island, a reference site in southern Chesapeake Bay. Samples were analyzed for 26 organochlorine pesticides and metabolities and 145 PCB congeners. Pesticide and metabolite concentrations, including p,p '-DDE, were well below thresholds associated with adverse reproductive effects at both sites. Average concentration of total PCBs, 12 Ah receptor–active PCB congeners, and toxic equivalents in eggs from Baltimore Harbor were greater (up to 35-fold) than that observed in Holland Island samples. Overall nest success at the Baltimore Harbor heronry was estimated by the Mayfield method to be 0.74, and the mean number of young fledged/hen was 2.05, which is within published productivity estimates for maintaining a stable black-crowned night-heron population. Using logistic regression, no significant relationships were found between organochlorine contaminant concentrations in sample eggs and hatching, fledging, or overall reproductive success. Processes other than poor reproduction ( e.g. , low postfledging survival, emigration, habitat degradation) may be responsible for the declining size of the Baltimore Harbor colony.

Maryland↗

Organochlorine contaminants in double-crested cormorants from Green Bay, Wisconsin: II. Effects of an extract derived from cormorant eggs on the chicken embryo

White Leghorn chicken ( Gallus domesticus ) eggs were injected prior to incubation with one of four concentrations (0.001, 0.01, 0.1, and 1.0 egg-equivalent) of an extract derived from 1,000 double-crested cormorant ( Phalacrocorax auritus ) eggs collected at Spider Island adjacent to Green Bay in Lake Michigan. One egg-equivalent corresponded to the concentration of contaminants present in an average cormorant egg. This was approximately 322 pg toxic equivalents (TEQs)/g, ww egg with polychlorinatedbiphenyl congener 126 (3,3′,4,4′,5-pentachlorobiphenyl) accounting for over 70% of the TEQs. Injection of 1.0 egg-equivalent resulted in 77% mortality at hatch. The incidence of developmental abnormalities (structural defects or edema) was not affected by injection of the extract. Body weight gain of chicks was reduced in the 1.0 egg-equivalent dose group in the first, second, and third week's post-hatch. Relative brain weights were greater and relative bursa weights were less in the 1.0 egg-equivalent dose group than in the vehicle control at three weeks of age. There were no significant differences in the relative weights of the heart, liver, spleen, testes, or comb among treated and control birds.

Wisconsin↗

The influence of extraction procedure on ion concentrations in sediment pore water

Sediment pore water has the potential to yield important information on sediment quality, but the influence of isolation procedures on the chemistry and toxicity are not completely known and consensus on methods used for the isolation from sediment has not been reached. To provide additional insight into the influence of collection procedures on pore water chemistry, anion (filtered only) and cation concentrations were measured in filtered and unfiltered pore water isolated from four sediments using three different procedures: dialysis, centrifugation, and vacuum. Peepers were constructed using 24-cell culture plates and cellulose membranes and vacuum extractors consisted of fused-glass air stones attached with airline tubing to 60-cc syringes. Centrifugation was accomplished at two speeds (2,500 and 10,000 g ) for 30 min in a refrigerated centrifuge maintained at 4°C. Only minor differences in chemical characteristics and cation and anion concentrations were found among the different collecting methods with differences being sediment-specific. Filtering of the pore water did not appreciably reduce major cation concentrations, but trace metals (Cu and Pb) were markedly reduced. Although the extraction methods evaluated produced pore waters of similar chemistries, the vacuum extractor provided the following advantages over the other methods: ease of extraction, volumes of pore water isolated, minimal preparation time, and least time required for extraction of pore water from multiple samples at one time.

Archives of Environmental Contamination and Toxico↗

Assessing the bioaccumulation of contaminants from sediments of the Upper Mississippi River using field-collected oligochaetes and laboratory- exposed Lumbriculus variegatus

Concern with the redistribution of contaminants associated with sediment in the upper Mississippi River (UMR) arose after the flood of 1993. This project is designed to evaluate the status of sediments in the UMR and is one article in a series designed to assess the extent of sediment contamination in navigational pools of the river. Companion articles evaluate sediment toxicity and benthic community composition in navigation pools of the river. The objectives of the present study were to: (1) to assess the bioaccumulation of sediment-associated contaminants in the UMR using laboratory exposures with the oligochaete Lumbriculus variegatus, and (2) to compare bioaccumulation in laboratory-exposed oligochaetes to field-collected oligochaetes. Sediment samples and native oligochaetes were collected from 23 navigational pools on the Upper Mississippi River and the Saint Croix River. Contaminant concentrations measured in the L. variegatus after 28-day exposures to sediment in the laboratory were compared to contaminant concentrations in field-collected oligochaetes from the 13 pools where these sediments were collected. Contaminant concentrations were relatively low in sediments and tissues from the pools evaluated. Only polycyclic aromatic hydrocarbons (PAHs) and total polychlorinated biphenyls (PCBs) were frequently measured above detection limits. The majority of the biota- sediment-accumulation factors (BSAFs) for PAHs were within a range of about 1.0 to 2.6, suggesting that the theoretical BSAF value of 1.7 could be used to predict these mean BSAFs with a reasonable degree of certainty. A positive correlation was observed between lipid-normalized concentrations of PAHs detected in laboratory-exposed and field-collected oligochaetes across all sampling locations. Rank correlations for concentrations of individual compounds between laboratory-exposed and field-collected oligochaetes were strongest for benzo(e)pyrene, perylene, benzo(b,k)fluoranthene, and pyrene. About 90% of the paired PAH concentrations in laboratory-exposed and field- collected oligochaetes were within a factor of three of one another indicating laboratory results could be extrapolated to the field with a reasonable degree of certainty.

Archives of Environmental Contamination and Toxico↗