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At least 829 records · Page 46Linked to original sources
USGS1990

Environmental contaminant concentrations in biota from the lower Savannah River, Georgia and South Carolina

Planned harbor expansion and industrial developments may adversely affect the economically important aquatic resources of the lower Savannah River, including those at the Savannah National Wildlife Refuge. To establish the present level of chemical contamination in this system, we collected a total of 102 samples of nine species of fish and fiddler crabs (Uca pugilator) from eleven sites in the lower Savannah River and on the Savannah National Wildlife Refuge, and analyzed them for concentrations of organochlorine chemicals, aliphatic and aromatic petroleum hydrocarbons, and 13 elemental contaminants: aluminum, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, selenium, and zinc. Residues of DDT (mainly as DDE),trans-nonachlor, dieldrin, Aroclor? 1260, mirex, and petroleum hydrocarbons were common in fish from the lower Savannah River, but concentrations were below those warranting environmental concern. In general, the concentrations of elemental contaminants also were low; however, arsenic, cadmium, and chromium concentrations were elevated in fish from river stations near the city of Savannah, and lead was elevated in samples from the National Wildlife Refuge. Contamination of the lower Savannah River by organic and elemental contaminants, as indicated by concentrations in fishes and fiddler crabs, did not appear to pose a hazard.

Archives of Environmental Contamination and Toxico↗
USGS1990

Fluoride accumulation and bone strength in wild black-crowned night-herons

Fluoride was measured in femurs of black-crowned night-herons ( Nycticorax nycticorax ) living adjacent to a phosphate processing complex near Pocatello, Idaho. Fluoride (ash wt.) in femurs ranged from 540 μg/g to 11,000 μg/g and increased (P=0.0001) with age, but with no difference (P=0.80) between sexes. Adult males (⩾4 years) contained 5,409 μg/g compared to 6,042 μg/g for adult females. The tibiotarsus (=tibiae in text) increased in diameter with age (P=0.015) in this study; fluoride was nearly related (P=0.065) to the increase. As the diameter increased with age, wall thickness decreased (P=0.011) suggesting excessive internal bone resorption, but fluoride concentrations were not implicated in the relationship (p= 0.64). The apparent increase in diameter and decrease in wall thickness may have partially neutralized each other's effects on strength. Although significantly higher concentrations of fluoride were present in adults than in Third Year herons, no significant change in bone strength (maximum load or modulus of rupture) was detected between the two age classes, but three of the four comparisons showed adults with less strength ( i.e. , a hint of diminished strength with age). The tibiae of Hatch Year birds were significantly weaker than documented in older age classes, but incomplete growth was thought responsible. The strong relationship between age and fluroide concentrations reduced our ability to separate a “fluoride effect” from an “age effect.” Other authors believed fluoride was responsible for an increase in bone diameter and the fluoride residues encountered in adults were within the range indicative of poisoning in cattle. In addition, the adult night-herons had about 1.6 times higher fluoride concentrations than owls which showed reduced reproductive success under laboratory conditions.

Archives of Environmental Contamination and Toxico↗
USGS1986

Reproduction of bobwhites fed different dietary concentrations of an organophosphate insecticide, methamidophos

Pairs of first-year breeding bobwhites were fed constant or variable concentrations of methamidophos for 15 days, or a control diet in a pair-fed design in which they were matched by body weights to pairs in the constant group. Treatments for the constant group were 5.0, 7.8, 12.3, 19.2, and 30.0 ppm for 5 pairs at each concentration. The number of pairs per concentration and peak concentrations for the variable pairs were identical to the constant dosages. Concentrations for the variable group were increased by a factor of four during two 3-day periods in order to reach the peak concentrations on days 7–9 after which they were decreased by 18% every 3 days to correspond to an environmental half-time of 10.5 days. Food consumption, egg production, hatchability of eggs under artificial incubation, and survival of hatched chicks for 2 weeks were recorded for each pair during 15-day treatment and 21-day posttreatment periods. Mortality was high in the highest constant dosage (2/10) and the associated pair-fed groups (3/10). Food consumption and egg production rates were negatively dose-related during the treatment period in the constant and variable groups. The laying rate of pair-fed hens was reduced to the same extent as in the constant group. Reproductive inhibition was not permanent and pairs resumed laying after a dose-related recovery interval. No dose-related effects on hatchability or chick survival were detected. Furthermore, there was no evidence of a pesticide effect on reproduction in addition to that exerted through pesticide-induced anorexia.

Archives of Environmental Contamination and Toxico↗
USGS1986

Wildlife in some areas of New Mexico and Texas accumulate elevated DDE residues, 1983

Over the last decade, data gathered by the U.S. Fish & Wildlife Service's National Contaminant Biomonitoring Program have identified an area of elevated DDE contamination in portions of New Mexico and Texas. Extensive wildlife sampling in 1983 confirmed that DDE, the major metabolite of the insecticide DDT, was present at high concentrations in wildlife at selected sites in the Rio Grande and Pecos River drainages. DDE in carcasses ranged up to 47 ppm (wet weight) in western kingbirds ( Tyrannus verticalis ), 35 ppm in house sparrows ( Passer domesticus ), 46 ppm in Brazilian free-tailed bats ( Tadarida brasiliensis ), and 104 ppm in whiptail lizards ( Cnemidophorus spp.). DDE was also detected in gut contents from western kingbirds at some of the highest concentrations ever reported, ranging up to 21 ppm in proventricular samples. An average of 40% of the eggs of black-crowned night-herons ( Nycticorax nycticorax ) from two sites along the Pecos River in New Mexico had DDE levels (≥8 ppm) that have been associated in other studies with impaired reproduction. In contrast, wintering mallards ( Anas platyrhynchos ) and American coots ( Fulica americana ) from the study area did not accumulate elevated DDE levels. DDE in wildlife samples at control sites (nonagricultural areas) was either absent or averaged less than 0.35 ppm. Collectively, these data provide evidence that there is major DDE contamination of several vertebrate species in portions of the Rio Grande and Pecos River drainages, but whether the contamination is recent or residual was not determined. Apparently, the source was not DDE contamination present in dicofol (4-chloro- a -(4-chlorophenyl)- a -(trichloromethyl) benzenemethanol); neither dicofol nor its metabolite, p,p' -dichlorobenzophenone, were detected in wildlife carcasses (0.1 ppm detection limit) or proventricular contents (0.01 ppm detection limit) of western kingbirds.

New Mexico, Texas↗
USGS1991

Lead accumulation and osprey production near a mining site on the Coeur d'Alene River, Idaho

Mining and smelting at Kellogg-Smelterville, Idaho, resulted in high concentrations of lead in Coeur d'Alene (CDA) River sediments 15–65 km downstream, where ospreys ( Pandion haliaetus ) nested. Adult and nestling ospreys living along the CDA River had significantly higher blood lead concentrations than those at Lake Coeur d'Alene (intermediate area) or Pend Oreille and Flathead Lakes (reference areas). Lead concentrations in fish collected from the study areas paralleled those found in ospreys. Inhibition of blood δ-aminolevulinic acid dehydratase (ALAD) activity and elevation of protoporphyrin concentration provided evidence of lead exposure. In adult ospreys, ALAD activity was negatively correlated with lead in blood (r=−0.57), whereas protoporphyrin was positively correlated with lead in blood (r=+0.40). Neither hemoglobin nor hematocrit was adversely affected by the relatively modest lead concentrations found in the blood. Pronounced accumulation of lead by adults or young could ultimately result in behavioral abnormalities or death, both of which would reduce productivity of the nesting osprey population. We did not observe death related to lead, behavioral abnormalities, or reduced productivity during this 1986–87 study. Despite some lead-induced biochemical changes in blood parameters, ospreys produced young at nearly identical rates in the three study areas; these rates were among the highest ever reported in the western United States. Post-fledging survival of ospreys exposed to lead early in life remains an unknown. Lead does not biomagnify in the food chain as do organochlorine pesticides and mercury and several osprey behavior traits reduce the potential for the species to accumulate critical levels of lead. Swans, which feed at a lower trophic level, continue to die from environmental lead in the region.

Idaho↗
USGS1988

Organochlorine pesticides, polychlorinated biphenyls, and mercury in osprey eggs – 1970-79 – And their relationships to shell thinning and productivity

Osprey ( Pandion haliaetus ) eggs were collected in 14 states in 1970–79 and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury. Moderate shell thinning occurred in eggs from several areas. DDE was detected in all eggs, PCBs in 99%, DDD in 96%, dieldrin in 52%, and other compounds less frequently. Concentrations of DDT and its metabolites declined in eggs from Cape May County, New Jersey between 1970–72 and 1978–79. Eggs from New Jersey in the early 1970s contained the highest concentrations of DDE. Dieldrin concentrations declined in eggs from the Potomac River, Maryland during 1971–77. Five different contaminants were significantly negatively correlated with shell thickness; DDE was most closely correlated. Ten percent shell thinning was associated with 2.0 ppm DDE, 15% with 4.2 ppm, and 20% with 8.7 ppm in eggs collected from randomly selected nests before egg loss. Shell thickness could not be accurately predicted from DDE concentrations in eggs collected after failure to hatch, presumably because the eggs with the thinnest shells had been broken and were unavailable for sampling. DDE was also significantly negatively correlated with brood size. Other contaminants did not appear to adversely affect shell thickness or reproductive success.

Archives of Environmental Contamination and Toxico↗
USGS1991

Effects of mercury, selenium, and organochlorine contaminants on reproduction of Forster's terns and black skimmers nesting in a contaminated Texas bay

Mean mercury (0.40 μg/g), and geometric mean DDE (1.6 μg/g) and polychlorinated biphenyl (PCB) (2.3 μg/g) concentrations in Forster's tern ( Sterna forsteri ) eggs from Lavaca Bay were higher than those in tern eggs from a reference area in San Antonio Bay, but residues were not correlated with hatching success. Nest success was similar between bays. Selenium levels in Lavaca Bay tern eggs (0.71 μg/g) were also comparable to those in eggs from the reference area (0.68 μg/g). Clutch size (3.1 to 3.4) of Lavaca Bay black skimmers ( Rynchops niger ) was no different than that (3.4) at a reference colony near Laguna Vista. Nest success was similar among three Lavaca Bay colonies, but success was lower at one Lavaca Bay colony (40%) than at Laguna Vista (65%). Mean mercury (0.46 μg/g) and selenium (0.75 μg/g) concentrations in skimmer eggs from Lavaca Bay were higher than those (0.19, 0.33 μg/g) from Laguna Vista; however, concentrations of neither contaminant were related to hatching success. DDE concentrations in Lavaca Bay skimmer eggs (3.4 μg/g) were similar to those from Laguna Vista (3.2 μg/g) and DDE was negatively correlated with hatching success. PCBs were higher in eggs from Lavaca Bay (1.3 μg/g) than Laguna Vista (0.8 μg/g). Organochlorine and metal contaminants in most eggs were below embryotoxic levels. Eggshell thinning in Forster's terns (7%) and black skimmers (5%) was below that associated with lowered reproduction. DDE and PCBs were detected in 9 Caspian tern ( S. caspia ) eggs; maximum concentrations were 4.7 and 5.4 μg/g. Caspian tern and least tern ( S. albifrons ) eggs contained low (⩽0.9 μg/g) concentrations of mercury and selenium.

Texas↗
USGS1991

Eggshell modifications in captive American kestrels resulting from Aroclor 1248 in the diet

American kestrels ( Falco sparverius ) were fed diets containing 3 μg/g Aroclor ® 1 1248 or control diets from mid-January until July. Eggs were removed from first clutches 2 to 4 days after laying ceased and shell thickness and shell dimensions were measured. Contents of the third egg of each clutch, the carcasses of all adults that received Aroclor ® 1248 and of three males and three females that received the control diet were analyzed for DDE, Aroclors ® 1248, 1254 and 1260, and dieldrin. Concentrations of PCBs, DDE and dieldrin were significantly higher (P < 0.03) in eggs and carcasses from treated adults than in controls. Shell thickness and shell thickness index of eggs from treated adults were reduced 5.0% (P < 0.0001) and 4.8% (P < 0.0001), respectively, from those of controls.

Archives of Environmental Contamination and Toxico↗
USGS1991

Effects of color on cadmium and lead levels in avian contour feathers

The use of feathers has been proposed as a noninvasive tissue for biomonitoring metal levels in birds and their ecosystems. We examined cadmium and lead levels in black and white contour feathers from common (Sterna hirundo) and sooty (S. fuscata) terns, and black skimmers (Rynchops niger) to determine if there were significant differences in metal levels related to the melanin content of the feathers. There were no significant differences in metals in black versus white body feathers in any of the three species; correlations between metal residues from individual birds were low. © 1991 Springer-Verlag New York Inc.

Archives of Environmental Contamination and Toxico↗
USGS1986

Organochlorine chemical residues in bluegills and common carp from the irrigated San Joaquin Valley floor, California

Samples of bluegills ( Lepomis macrochirus ) and common carp ( Cyprinus carpio ) collected from the San Joaquin River and two tributaries (Merced River and Salt Slough) in California were analyzed for 21 organochlorine chemical residues by gas chromatography to determine if pesticide contamination was confined to downstream sites exposed to irrigated agriculture, or if nonirrigated upstream sites were also contaminated. Residues of p,p′ -DDE were detected in all samples of both species. Six other contaminants were also present in both species at one or more of the collection sites: chlordane ( cis -chlordane + trans -nonachlor); p,p′ -DDD; o,p′ -DDT; p,p′ -DDT; DCPA (dimethyl tetrachloroterephthalate); and dieldrin. Concentrations of most of these residues were generally higher in carp than in bluegills; residues of other compounds were found only in carp: α-BHC (α-benzenehexachloride), Aroclor ® 1260, and toxaphene. Concentrations of most organochlorines in fish increased from upstream to downstream. Water quality variables that are influenced by irrigation return flows ( e.g. , conductivity, turbidity, and total alkalinity) also increased from upstream to downstream and were significantly correlated ( P < 0.05) with organochlorine residue levels in the fish. In carp, concentrations of two residues-⌆DDT ( p,p′ -DDD + p,p′ -DDE + + p,p′ -DDT; 1.43 to 2.21 mg/kg wet weight) and toxaphene (3.12 mg/kg wet weight)-approached the highest levels reported by the National Pesticide Monitoring Program for fish from other intensively farmed watersheds of the United States in 1980 to 1981, and surpassed criteria for whole-body residue concentrations recomended by the National Academy of Sciences and National Academy of Engineers for the protection of piscivorous wildlife.

California↗
USGS1986

Population trends, reproductive success, and organochlorine chemical contaminants in waterbirds nesting in Galveston Bay, Texas

The effects of environmental contaminants on the reproductive success of olivaceous cormorants ( Phalacrocorax olivaceus ), laughing gulls ( Larus atricilla ), and black skimmers ( Rhynchops niger ) nesting in Galveston Bay, Texas were investigated from 1980 through 1982. Populations of cormorants and gulls have remained stable in recent years, but skimmer numbers may have declined. Cormorants produced 1.9 to 2.8 young per pair in nests that remained active throughout the season. Gull and skimmer reproduction was seriously limited by storms and predation. DDE and polychlorinated biphenyl (PCB) residues in carcasses and eggs generally were below levels associated with chronic poisoning and reproductive problems in most species of birds. Possible exceptions were four black skimmer carcasses with DDE concentrations that ranged from 20 to 92 Μ g/g and one olivaceous cormorant carcass with 20 Μ g/g DDE. The generally low levels of dieldrin, chlordane, HCB, toxaphene, and heptachlor epoxide were below those know to affect avian reproduction and survival. Mean DDE residues in cormorant and gull eggs were less than 1.8 Μ g/g. The mean DDE residue in skimmer eggs was less than 3.3 Μ g/g; 12% of the skimmer eggs contained at least 12 Μ g/g DDE, a level known to cause reproductive problems in some avian species. DDE in the eggs of all species declined from 1.5- to 7-fold over the past decade. Polychlorinated biphenyl was detected in all gull and skimmer eggs and in 90% of the cormorant eggs. Residues of PCB in cormorant and skimmer eggs in 1980–82 were lower than in 1970, but the frequency of occurrence in gull eggs increased. Polychlorinated styrenes were recovered in 45% of the cormorant carcasses at levels below 1 Μ g/g. Eggshell thicknesses in all three species were similar to those of eggshells collected before the widespread use of DDT.

Texas↗
USGS1993

Boron, molybdenum, and selenium in aquatic food chains from the lower San Joaquin River and its tributaries, California

Boron (B), molybdenum (Mo), and selenium (Se) were measured in water, sediment, particulate organic detritus, and in various biota—filamentous algae, net plankton, macroinvertebrates, and fishes—to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage during the spring and fall 1987, in the San Joaquin River, California. Concentrations of B and Se, but not Mo, were higher in most samples from reaches receiving tile drainage than in samples from reaches receiving no tile drainage. Maximum concentrations of Se in water (0.025 μg/mL), sediment (3.0 μg/g), invertebrates (14 μg/g), and fishes (17 μg/g) measured during this study exceeded concentrations that are detrimental to sensitive warmwater fishes. Toxic threshold concentrations of B and Mo in fishes and their foods have not been identified. Boron and Mo were not biomagnified in the aquatic food chain, because concentrations of these two elements were usually higher in filamentous algae and detritus than in invertebrates and fishes. Concentrations of Se were lower in filamentous algae than in invertebrates and fishes; however, concentrations of Se in or on detritus were similar to or higher than in invertebrates and fishes. These observations suggest that high concentrations of Se accumulated in invertebrates and fishes through food-chain transfer from Se-enriched detritus rather than from filamentous algae.

Archives of Environmental Contamination and Toxico↗
USGS1993

Uptake of planar polychlorinated biphenyls and 2,3,7,8-substituted polychlorinated dibenzofurans and dibenzo- p -dioxins by birds nesting in the lower Fox River and Green Bay, Wisconsin, USA

The uptake of persistent polychlorinated hydrocarbons (PCHs) by four avian species was investigated at upper trophic levels of two aquatic food chains of the lower Fox River and Green Bay, Wisconsin. Accumulation of total and specific planar polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxin (PCDDs), and H411E rat hepatoma cell bioassay-derived 2,37,8-tetrachlorodibenzop-dioxin equivalents (TCDD-EQ) was evaluated in Forster's tern ( Sterna forsteri ) and common tern ( Sterna hirundo ) chicks, and in tree swallow ( Tachycineta bicolor ) and red-winged blackbird ( Agelaius phoeniceus ) nestlings from colonies nesting in several locations within the watershed. Concentrations of the PCHs were greatest in eggs and chicks of the two tern species, less in the tree swallows and least in the red-winged blackbirds. Young of all four species accumulated total PCBs, PCB congeners 77, 105, 126, and 169, and TCDD-EQ. The young birds also accumulated small concentrations of several 2,3,7,8-sbustituted PCDF and PCDD congeners. Uptake rates for certain of the PCHs for the Forster's tern chicks were: 15 μg/day for total PCBs, 70, 200, 6.5, and 0.14 ng/day for PCB congeners 77, 105, 126, and 169, respectively, and 270 μg/day for TCDD-EQ. Principal components analysis revealed that the patterns of PCH concentrations in the samples were influenced by species of bird, their age (or length of exposure) and nesting location. Collectively, our findings demonstrate that exposure of avian species to contaminants derived from aquatic food chains can be characterized and quantified for the purposes of ecological risk assessment.

Wisconsin↗
USGS1993

2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents in tissues of birds at Green Bay, Wisconsin, USA

The environment has become contaminated with complex mixtures of planar, chlorinated hydrocarbons (PCHs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p -dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and structurally similar compounds. Because the potencies of individual congeners to cause the same adverse effects vary greatly and the relative as well as absolute concentrations of individual PCH vary among samples from different locations, it is difficult to assess the toxic effects of these mixtures on wildlife. These compounds can cause a number of adverse effects, however, because the toxic effects which occur at ecologically-relevant concentrations such as embryo-lethality and birth defects appear to be mediated through the same mechanism, the potency of individual congeners can be reported relative to 2,3,7,8-tetrachlorodibenzo- p -dioxin (2,3,7,8-TCDD) which is the most toxic congener in the PCH class. The concentations of 2,3,7,8-TCDD Equivalents (TCDD-EQ) were determined in the tissues of aquatic and terrestrial birds of Green Bay, Wisconsin by the H4IIE bioassay system and compared toxic equivalency factors (TEFs) with the concentration predicted by the use of toxic equivalency factors applied to concentrations of PCH, which were determined by instrumental analyses. Concentrations of TCDD-EQ ranged from 0.52 to 440 ng/kg, wet weight. The greatest concentrations occurred in the fish-eating birds. Concentrations of TCDD-EQ, which were determined by the two methods were significantly correlated, but the additive model which used the TEFs with concentrations of measured PCB, PCDD and PCDF congeners underestimated the concentrations of TCDD-EQ measured by the H4IIE bioassay by an average of 57%. This is thought to be due to contributions from un-quantified PCH, which are known to occur in the environment. Of the quantified PCH congeners, PCDD and PCDF contributed a small portion of the TCDD-EQ in the aquatic birds, while most of the TCDD-EQ were due to non-ortho-substituted PCBs. In the terrestrial birds, the proportion of the TCDD-EQ contributed by the PCDD and PCDF was greater. This paper has been reviewed in accord with U.S. Environmental Protection Agency policy. Mention of specific products or trade names does not imply endorsement by the U.S. Government.

Archives of Environmental Contamination and Toxico↗
USGS1993

Effects of dietary aluminum, calcium, and phosphorus on egg and bone of European starlings

Egg and bone of passerine birds nesting in acidified habitats may be affected by high levels of Al or P, or low levels of Ca. Nine treatments of three levels of dietary Al (target levels of 200, 1,000, and 5,000 μg/g) and three levels of Ca:P (target levels of NN = 1.3% Ca: 0.9% P; LL = 0.19 Ca:0.45 P; LH = 0.19 Ca: 1.65 P) were fed to 16–17 starling pairs during two breeding seasons. Eggs of starlings fed the LH diet were smaller and weighed less than eggs from the NN and LL treatments. Treatment effects on thickness, strength, and weight of eggshells were not consistent between seasons, probably because of differences in actual dietary levels of Al, Ca, and P or in incubation intervals. In one season, birds fed the highest Al diet had thicker eggshells than those from the other Al treatments (no effect from Ca:P); the following season, eggshells from the NN and LH treatments were thicker and stronger than those from the LL treatment. Eggshells from the NN treatment weighed more than those from the other Ca:P treatments. Starlings on the LH diet had the strongest femurs, but the effect was interactive with different levels of dietary Al. Effects of Ca:P on egg and bone were more evident than Al effects.

Archives of Environmental Contamination and Toxico↗
USGS1993

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

Bald eagle ( Haliaeetus leucocephalus ) eggs were collected in 15 States in the United States in 1980–1984 and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury. Data were compared and combined with data from earlier studies to examine trends and refine relationships of contaminants to shell thickness and young production. Moderate shell thinning occurred in eggs from several States. The frequency of occurrence of detectable residues of several contaminants declined during 1969–84. DDE concentrations declined significantly in Wisconsin, Maine, and the Chesapeake Bay region. Some other contaminant residues declined, but usually not significantly. During 1980–84, DDE, PCB, and mercury concentrations were highest in eggs from Maine, whereas most contaminant concentrations were lowest in eggs from Arizona. DDE was most closely related to shell thickness and young production at sampled breeding areas. Fifteen percent shell thinning was associated with 16 μg/g DDE (wet weight) for eggs collected early in incubation. Young production was normal when eggs at sampled breeding areas contained < 3.6 μg/g DDE (wet weight), was nearly halved between 3.6 to 6.3 μg/g, and halved again when concentrations exceeded 6.3 μg/g. Several other contaminants were also associated with poor reproduction and eggshell thinning; however, their impact appeared to be secondary to that of DDE and was probably related to their high correlation with DDE. Data relating contaminant concentrations to mean 5-year production are applicable only to breeding areas where eggs are collected after failure to hatch, because such breeding areas are not representative of all nesting bald eagles in a given population.

Archives of Environmental Contamination and Toxico↗
USGS1989

Contaminants in foods of aquatic birds at Kesterson Reservoir, California, 1985

Plants, aquatic insects, and mosquitofish ( Gambusia affinis ) were collected from Kesterson Reservoir, Merced County, California, and a nearby reference site (Volta Wildlife Area) to compare concentrations of three contaminants found in 1985 with those reported in 1983 and 1984. Mean selenium concentrations in food-chain organisms from sites at Kesterson in 1985 ranged from 26.0 μg/g (dry wt) in water boatman (Corixidae) to 119 μg/g in mosquitofish. All mean selenium concentrations at Kesterson were significantly higher than those from Volta and were sufficient to have caused the impaired avian reproduction observed at Kesterson. Boron concentrations were also significantly higher at Kesterson, and, at one pond, the mean concentration in widgeongrass ( Ruppia mari-tima ) (1,630 μg/g) was high enough to impair avian reproduction. There were no differences in arsenic concentrations between locations, and concentrations in all food-chain organisms (<1.9 μg/g) were lower than those reported to cause adverse effects in wildlife. Within-location differences were observed for all three contaminants at Kesterson and for selenium at Volta, but there was no consistent pattern to these differences. Between-year comparisons showed that selenium concentrations in mosquitofish generally decreased at Kesterson, but remained about the same at Volta over the 3 years. Selenium concentrations in insects from 1985 were lower at Kesterson than 1983, but were similar to 1984. Concentrations in plants were generally higher in 1983 and lower in 1984 compared with 1985. Boron concentrations in plants were generally higher in 1985, but in mosquitofish and insects, boron concentrations remained about the same all 3 years. Most arsenic concentrations did not change significantly between years.

California↗
USGS1989

Selenium accumulation by raccoons exposed to irrigation drainwater at Kesterson National Wildlife Refuge, California, 1986

In February–March 1986, eight raccoons ( Procyon lotor ) were collected at Kesterson Reservoir (Merced Co., California), which had received selenium-contaminated irrigation drainwater, and four raccoons were collected at the nearby Volta Wildlife Area, which had not. Selenium concentrations in Kesterson raccoons averaged 19.9 ppm (μg/g dry wt) in liver, 28.3 ppm (dry wt) in hair, 21.6 ppm (dry wt) in feces, and 2.61 ppm (wet wt) in blood and exceeded Volta concentrations by 12, 30, 21, and 10 times, respectively. Selenium concentrations in livers of Kesterson raccoons were less than those in five of nine other mammal species sampled in 1984. Selenium concentrations in hair provided the strongest statistical separation between study areas. Hemoglobin levels in two Kesterson raccoons equalled levels reported in rats with selenium-induced anemia, but the raccoons showed no illness. Amyloidosis in one Kesterson raccoon may have been selenium-induced. Our data indicate that raccoon births peaked about 2 months later than was previously reported. Based on our sample of 12 raccoons, we found no evidence that contamination by irrigation drainwater had negative effects on raccoons inhabiting Kesterson.

California↗