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At least 1,711 records · Page 95Linked to original sources
USGS1973

Population dynamics of pond zooplankton, I. Diaptomus pallidus Herrick

The simultaneous and lag relationships between 27 environmental variables and seven population components of a perennial calanoid copepod were examined by simple and partial correlations and stepwise regression. The analyses consistently explained more than 70% of the variation of a population component. The multiple correlation coefficient (R) usually was highest in no lag or in 3-week or 4-week lag except for clutch size in which R was highest in 1-week lag. Population control, egg-bearing, and clutch size were affected primarily by environmental components categorized as weather; food apparently was relatively minor in affecting population control or reproduction. ?? 1973 Dr. W. Junk B.V. Publishers.

Hydrobiologia↗
USGS1991

Growth and overwinter survival of the Asiatic clam, Corbicula fluminea, in the St. Clair River, Michigan

We report the discovery in April 1986 of the first population of Asiatic clam, Corbicula fluminea, known to occupy a lotic environment in the Laurentian Great Lakes system. This population occupied a 3.8 km long sandy shoal in the discharge plume of a steam-electric power plant on the St. Clair River (Michigan), the outflow of Lake Huron. Samples collected April 1986 to April 1987 revealed the growth of one-year-old Corbicula (1985 cohort) began after mid-May and ended by mid-November, while water temperatures were higher than 9°C. Maximum growth (0.78 mm wk -1 ) occurred between mid-August and mid-September, while water temperatures were about 16-23°C. We recorded a substantial overwinter mortality of the 1986 cohort, but not the 1985 cohort; this was particularly evident at sampling locations more remote from the heated discharge of the power plant, suggesting low water temperature wast the major mortality agent. The available information suggests low water temperature in the St. Clair River may limit the success of Corbicula in the river, including portions of populations inhabiting thermal plumes, by reducing growth, delaying the onset of sexual maturity and reproduction, and causing heavy overwinter mortality in the first year of life.

Michigan↗
USGS1986

Distribution of early life history stages of fishes in selected pools of the upper Mississippi River

Effective management of the fishery resources of the Upper Mississippi River and successful mitigation of the loss of critical habitat depend in part on an understanding of the reproductive and early life history requirements of the affected fishes. However, little is known about the use of nursery areas by fishes in the river. Of the nearly 130 species identified in the adult ichthyofauna, only a few are represented proportionally in the available data on early life stages because study designs have not included consideration of the early stages, collection gears have not adequately sampled the young, and eggs and larvae of some species are difficult to sample by conventional approaches. For the species collected, information is available on seasonal variations in total densities, composition, and catch among different habitat types. However, the data are most accurate for species with buoyant early life stages, such as freshwater drum ( Aplodinotus grunniens ) and gizzard shad ( Dorosoma cepedianum ). Eggs and larvae of freshwater drum dominate collections made in the main channel, whereas other larval fishes are usually most abundant in backwater habitats. The species found there usually deposit eggs on the substrate or on vegetation. Habitat preferences (as indicated by relative abundance) often shift as development proceeds and physical and behavioral changes occur in the larvae. Only limited information is available on the distribution of larvae within habitats, but it is clear that variations within habitats are significant.

Hydrobiologia↗
USGS1992

Trace element and organochlorine concentrations in California clapper rail (Rallus longirostris obsoletus) eggs

Trace contaminant concentrations were measured in eggs of endangered California clapper rails ( Rallus longirostris obsoletus ) collected from San Francisco Bay during 1975, 1986, and 1987, and in clapper rail eggs ( R. l. waynei ) from North Carolina during 1987. Residues of 10 detected organochlorines (OC) were low and decreased by 2 to 3-fold from 1975 to 1986–1987 for San Francisco Bay samples, whereas eggshell thickness remained unchanged and comparable to eggs collected prior to 1940. Mercury (Hg) concentrations in eggs from San Francisco Bay were higher than those from North Carolina, and comparable to concentrations associated with reproductive effects in other avian species. Selenium (Se) concentrations in eggs from San Francisco Bay were also higher than those from North Carolina, and were highest in a north San Francisco Bay marsh adjacent to an oil refinery. Individual Se concentrations were slightly lower than values associated with embryotoxicity in other rallids. We recommend additional research on the effects of these and other contaminants on California clapper rails and the restoration of rail habitat.

California↗
USGS1995

Contaminants in fishes from great lakes-influenced sections and above dams of three Michigan Rivers: III. Implications for health of bald eagles

Recently, there have been discussions of the relative merits of passage of fishes around hydroelectric dams on three rivers (Au Sable, Manistee, and Muskegon) in Michigan. A hazard assessment was conducted to determine the potential for adverse effects on bald eagles that could consume such fishes from above and below dams on the three primary rivers. The hazard assessments were verified by comparing the reproductive productivities of eagles nesting in areas where they ate primarily fish from either above or below dams on the three primary rivers, as well as on two additional rivers in Michigan, the Menominee and Thunder Bay. Concentrations of organochlorine insecticides (OCI), polychlorinated biphenyls (total PCBs), 2,3,7,8-tetrachlorodibenzo- p -dioxin equivalents (TCDD-EQ), and total mercury (Hg) were measured in composite samples of fishes from above and below hydroelectric dams on the Manistee and Muskegon Rivers, which flow into Lake Michigan, and the Au Sable River, which flows into Lake Huron. Mean concentrations of OCI, total PCBs, and TCDD-EQ were all greater in fishes from below the dams than in those from above. The hazard assessment indicated that current concentrations of Hg and OCI other than DDT (DDT + DDE + DDD) in fish from neither above nor below dams would present a significant hazard to bald eagles ( Haliaeetus leucocephalus ). Both total PCBs and TCDD-EQ in fishes from below the dams currently present a significant hazard to bald eagles, since their mean hazard quotients (HQ) were all greater than one.

Michigan↗
USGS1992

Aquatic hazard assessment of the organophosphate insecticide fonofos

This study determined the acute and chronic toxicity of the organophosphate insecticide fonofos to standard freshwater aquatic organisms under laboratory conditions. Fonofos was acutely toxic to bluegill (Lepomis macrochirus), Daphnia (D. magna) , and midge (Chironomous riparius) at 5.3, 2.7, and 39 μg/L, respectively. Three fonofos formulations (technical, 94.8% A.I.; 20G, field granular 20% A.I.; and 4E, field liquid 4#/gal A.I.) exhibited similar acute toxicities to bluegill. Exposure to fonofos delayed reproduction and decreased the intrinsic rate of increase of Daphnia during 21-d chronic exposure at the lowest tested concentration (0.08 μg/L). The no observable effect concentration (NOEC) for Daphnia survival was 0.42 μg/L; 0% survival occurred at the lowest observable effect concentration (LOEC) of 1.45 μg/L. The NOEC for midge emergence was 3.42 μg/L; only 34% emergence occurred at the LOEC of 8.24 μg/L. Chronic 30-d exposure of juvenile bluegills decreased growth and survival at 5.65 μg/L (LOEC), but no effects occurred at 2.33 μg/L (NOEC). The relative hazard of fonofos to aquatic life is similar to other carbamate and organophosphate corn insecticides.

Archives of Environmental Contamination and Toxico↗
USGS1995

Selenium concentrations in the razorback sucker (Xyrauchen texanus): Substitution of non-lethal muscle plugs for muscle tissue in contaminant assessment

A single muscle plug was collected from each of 25 live razorback suckers inhabiting the Colorado River basin and analyzed for selenium by instrumental neutron activation. Eight fish from Ashley Creek and three from Razorback Bar exhibited selenium concentrations exceeding 8 &mu;g/g, a level associated with reproductive failure in fish. Concentrations of selenium in eggs and milt were significantly correlated with selenium concentrations in muscle plugs and together indicate a possible explanation for the decline of this species in the Colorado River basin. Muscle plugs (<50mg) and muscle tissue (20 g) were collected from dorsal, anterior, and posterior areas of common carp, flannelmouth sucker, and an archived razorback sucker and analyzed for selenium. Concentrations of selenium in muscle plugs were significantly correlated with selenium concentrations in muscle tissue from the same location and fish (r=0.97). Coefficients of variation for selenium concentrations in each fish were <6.5% for muscle tissue, but ranged from 1.5 to 32.4% for muscle plugs. Increased variation in muscle plugs was attributed to lower selenium concentrations found in the anterior muscle plugs of flannelmouth suckers. Mean selenium concentrations in muscle plugs and tissue from dorsal and posterior areas and muscle tissue from the anterior area were not significantly different. The non-lethal collection of a muscle plug from dorsal and posterior areas of the razorback sucker and other fish species may provide an accurate assessment of selenium concentrations that exist in adjacent muscle tissue.

Archives of Environmental Contamination and Toxico↗
USGS1983

Pack size and wolf pup survival: their relationship under varying ecological conditions

The relationship between pack size and two parameters of reproductive success (litter size at 7–8 months and pup weights at 5–6 months) were determined for two wolf ( Canis lupus ) populations in northern Minnesota. Pup weights were not correlated with pack size for either population. Litter size, however, was correlated with pack size, but the direction of the relationship varied between the two study populations. In the superior National Forest, where prey were scarce and the wolf population was declining from high densities, litter size and pack size were inversely related. Pairs produced more surviving pups than did larger packs with one or more potential helpers. In the Beltrami Island State Forest, where prey were relatively abundant and the wolf population was increasing, pack size and litter size were positively correlated. The results suggest that ecological factors, such as prey availability, affected the ability or willingness of various pack members to provide food or other care for the pups. The lack of correlation between number of auxiliaries and number of pups in canid populations with low and declining prey densities may be explained on the basis of heterogeneous prey density resulting in drastic annual variation in litter production. No study to date has measured the actual benefit that pups derive from helping by auxiliaries, and the costs and benefits of it. The relationships discussed herein can be considered valid only after such research is completed.

Behavioral Ecology and Sociobiology↗
USGS1985

Contaminant levels in colonial waterbirds from Green Bay and Lake Michigan, 1975–80

Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated styrenes (PCSs), and mercury were measured in the eggs of 10 species of colonial waterbirds nesting in areas around Green Bay or Lake Michigan from 1975 to 1980. Residues also were measured in the carcasses and brains of black-crowned night-herons ( Nycticorax nycticorax ). The highest residues were of PCBs, DDE, mercury, and dieldrin; for some species, levels of these chemicals possibly were high enough to have caused reproductive effects. Other organochlorine pesticides were found at low levels. Only trace amounts of PCSs and PBBs were found. Eggs of herring gulls ( Larus argentatus ) collected in 1977 from an island in Lake Michigan contained an average of 100 ppm PCBs and 33 ppm DDE; this was the most-contaminated species. Cattle egrets ( Bubulcus ibis ), the only bird that is not a fish eater, contained only small quantities of DDE and mercury.

Environmental Monitoring and Assessment↗
USGS1988

Organochlorine and mercury residues in Swainson's and ferruginous hawk eggs collected in North and South Dakota, 1974-79

Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury were measured in eggs of Swainson's hawks ( Buteo swainsoni ) and ferruginous hawks ( B. regalis ) collected in North and South Dakota during 1974–79. DDE was the most common compound detected in the eggs, but residues were below levels known to have adverse effects on reproduction. Other organochlorine compounds and mercury were found at low levels. Eggs of ferruginous hawks tended to contain more compounds with higher residues than eggs of Swainson's hawks.

Environmental Monitoring and Assessment↗
USGS1984

High PCB residues in birds from the Sheboygan River, Wisconsin

Organochlorine residues were measured in the carcasses and, in some cases, brains and stomach contents of four species of birds collected along the Sheboygan River, Wisconsin during the years 1976 to 1980. Polychlorinated biphenyls (PCBs) were high in all samples and were the contaminants of greatest concern. Carcass residues ranged from 23 to 218 ppm PCBs on a wet weight basis; these are levels associated with reproductive impairment in laboratory studies with some birds. Food items in the stomachs of collected birds contained from 12 to 58 ppm PCBs, indicating a heavy contamination of food sources. The brain of one bird contained 220 ppm PCBs, a level that is not in the lethal range but is very high. Birds feeding in the contaminated portions of the Sheboygan River may have been harmed by high PCB levels.

Wisconsin↗
USGS1990

Organochlorines and selenium in California night-heron and egret eggs

Exceptionally high concentrations of DDE were found in black-crowned night-heron ( Nycticorax nycticorax ) (geometric mean 8.62 μg g −1 wet wt.) and great egret ( Casmerodius albus ) (24.0 μg g −1 ) eggs collected from the Imperial Valley (Salton Sea), California in 1985. DDE concentrations in 14 of the 87 (16%) randomly selected night-heron eggs from six colonies (two in San Francisco Bay, three in the San Joaquin Valley, and one at Salton Sea) were higher than those associated with reduced reproductive success of night-herons (8 μg g −1 ). In addition, mean shell thickness of night-heron eggs collected from the San Joaquin Valley and from San Francisco Bay during 1982–1984 was significantly less than pre-DDT thickness and was negatively correlated ( r =−0.50, n =75, P <0.0001) with DDE concentration. Mean selenium concentration in night-heron eggs from Salton Sea (1.10 μg g −1 ) was significantly higher than in eggs from three locations in the San Joaquin Valley, and in egret eggs from Salton Sea.

Environmental Monitoring and Assessment↗
USGS1983

Temporal accumulation of organochlorine pesticides in shorebirds wintering on the south Texas coast, 1979-80

Organochlorine pesticide residues were determined in 168 shorebirds of three species collected at approximate bimonthly intervals during the fall and winter months of 1979–80 near Port Mansfield on the south Texas coast. The study was conducted to determine if shorebirds wintering on mudflats at the outlets of agricultural drains in Texas accumulated pesticides during this period. The predominant Organochlorine residues detected in shorebirds were DDE, dieldrin, and toxaphene. Ninety-five % of the skinned carcasses analyzed contained detectable levels of DDE, 13% contained dieldrin, and 22% contained toxaphene. DDE significantly increased in all species of shorebirds from October to December, with potentially dangerous levels accumulating in some long-billed dowitchers ( Limnodromus scolopaceus ) and American avocets ( Recurvirostra americana ), but DDE residues seldom exceeded 0.5 ppm in carcasses of western sandpipers ( Calidris mauri ). After about two months on the study area, no further residue increases were documented. The high levels of DDE detected in a large proportion of the dowitchers, and to a lesser extent in the avocets, are near or within the range known to inhibit reproduction in some avian species. This study demonstrates that certain aquatic areas near agricultural lands on the south Texas coast may be potential threats to waterbirds eight years after the use of DDT was banned in the United States.

Texas↗
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

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↗
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↗
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↗
USGS1982

Effects of a chemical dispersant and crude oil on breeding ducks

Effects of chemically dispersed crude oil on mallard reproduction. Incubating female mallards were exposed to a water source treated with either Prudhoe Bay crude oil, Corexit 9527, or a combination of oil and dispersant during the first 10 da of development. Used thermocouple probes to monitor incubation temperature. Measured hatching success, incubation temperature, and survival of ducklings to 1 wk of age.

Bulletin of Environmental Contamination and Toxico↗