bluuebunny/crossref_metadata_2025 huggingface dataset:
Exposure of female juvenile rainbow trout to alkylphenolic compounds results in modifications to growth and ovosomatic index
Authors: Ashfield Lindsey A , Pottinger Tom G , Sumpter John P
Published: March 2010

The alkylphenol ethoxylates (APEOs) are a major group of nonionic surfactants. Biodegradation of these compounds is incomplete during sewage treatment; thus, they are ubiquitous aquatic pollutants. All the main degradation products of APEOs were recently demonstrated to have estrogenic properties in vitro, but their effects in vivo remain to be established. In this study, female juvenile rainbow trout (Oncorhynchus mykiss Walbaum) were exposed to octylphenol, nonylphenol (NP), nonylphenol diethoxylate, and nonylphenol mono-carboxylic acid (NP1EC) at environmentally relevant concentrations (Experiment 1: 1, 10, and 50 μg/L; Experiment 2: 1, 10, and 30 μg/L). Exposure to APEOs commenced at hatch (day 0) and was terminated on day 22 (Experiment 1) or day 35 (Experiment 2). Body weight and fork length of representative samples offish from each treatment group were recorded at intervals up to 108 d (Experiment 1) or 466 d (Experiment 2). In Experiment 1, significant differences in size of the exposed fish, related to treatment, were still apparent on day 108, 86 d after withdrawal of the treatments. These observations were confirmed during Experiment 2, in which significant changes in body weight and fork length as a consequence of exposure to the compounds were observed approx. 15 d after exposure was terminated. These differences were sustained for at least 466 d in the case of NP and NP1EC. In addition, the ovosomatic index (OSI) offish exposed to NP and NP1EC was significantly affected zby the treatment. Survival of fish in the natural environment is strongly influenced by body size, and an appropriate OSI is a crucial factor in successful reproduction. Therefore, exposure of natural populations of fish to these chemicals at concentrations currently measurable in the aquatic environment may have an impact on the performance of those populations.
Reduction of aryl hydrocarbon receptor-mediated activity of polychlorinated biphenyl mixtures due to anaerobic microbial dechlorination
Authors: Quensen John F , Mousa Mahmoud A , Boyd Stephen A , Sanderson J Thomas , Froese Kenneth L , Giesy John P
Published: March 2010

Aroclors 1242 and 1254 were anaerobically dechlorinated by microorganisms eluted from polychlorinated biphenyl (PCB)-contaminated River Raisin (RR) and Silver Lake (SL) sediments. Dechlorination occurred primarily from the meta positions. H4IIE rat hepatoma cell bioassays for ethoxyresorufin-O-deethylase (EROD) induction potency, a measure of aryl hydrocarbon receptor-mediated toxic potential, revealed that the potencies of the Aroclors were considerably reduced after dechlorination. The decreases in EROD induction potencies were dependent on the extent of dechlorination of the non-ortho-substituted and mono-ortho-substituted PCBs. Calculated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TEqscalc) for the PCB mixtures were 5.7, 0.08, and 0.05 pM TEqcalc/μmole of PCBs for non-, RR-, and SL-dechlorinated Aroclor 1242, and 7.8, 1.6, and 1.0 pM TEqcalc/μmole of PCBs for non-, RR-, and SL-dechlorinated Aroclor 1254, respectively. Correspondence between TEqsassay determined using the H4IIE bioassay and TEqscalc indicated that no unexpected synergistic interactions occurred among components of the dechlorinated mixtures. These results indicate that the dioxinlike toxicities of PCB mixtures are substantially reduced by microbial reductive dechlorination, and that a constant ratio of TEq to total PCBs cannot be assumed in risk assessments.
Comparison of marine sediment toxicity test protocols for the amphipodRhepoxynius abroniusand the polychaete wormNereis (Neanthes) arenaceodentata
Authors: Anderson Brian S , Hunt John W , Phillips Bryn M , Tudor Shirley , Fairey Russell , Newman John , Puckett H Max , Stephenson Mark , Long Edward R , Tjeerdema Ronald S
Published: March 2010

The 10-d amphipod survival toxicity test protocol using Rhepoxynius abronius was compared to the 20-d polychaete worm growth and survival protocol using Nereis (Neanthes) arenaceodentata. Of the 341 sediment samples collected in California and tested over a 2-year period, 78% significantly inhibited R. abronius survival, whereas 2 and 26% significantly inhibited N. arenaceodentata survival and biomass, respectively. Statistical power associated with each protocol endpoint was determined by calculating the minimum significant difference (MSD) for each test protocol for this data set. The 90th percentile MSDs for R. abronius survival and N. arenaceodentata survival and biomass were 16, 36, and 56%, respectively. Survival of R. abronius was significantly negatively correlated with a number of toxicants including metals, pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. No significant correlations were determined between N. arenaceodentata survival or biomass and contaminants measured. Amphipod survival was also negatively correlated with sediment total organic carbon and grain size, but when samples with a high percent fine grain size (>90% fines) were eliminated from consideration, the overall conclusions of the study were not altered. The 10-d amphipod survival protocol using R. abronius was a more sensitive indicator of toxicity, but the results indicate that this was due to greater statistical power rather than greater sensitivity of the test organisms or endpoints.
Integrative assessment of sediment quality in two littoral ecosystems from the Gulf of Cádiz, Spain
Authors: DelValls T Ángel , Forja Jesús M , Gómez-Parra Abelardo
Published: March 2010

To evaluate sediment marine environmental quality in the Gulf of Cádiz, an integrative assessment approach was used—the sediment quality triad (SQT). Sediment samples were collected at seven stations in two littoral ecosystems and subjected to six separate, replicated sediment toxicity tests, comprehensive sediment chemistry analyses, and replicated benthic infaunal analyses. Chemistry analyses indicated that different contamination sources were associated with sediments highly contaminated with linear alkylbenzenesulfonates and some heavy metals associated with sewage discharges (Pb, and Ag), sediments with moderate levels of heavy metals associated with industrial activities (Hg, Cr, and As), and other sediments with slight or no contamination. Toxicity tests indicated that sediments close to the sewage discharges were most toxic, those associated with slight or no contamination were not toxic, and those associated with both sewage discharges and industrial sources of contamination were intermediate. Infaunal analyses indicated that communities at the salt-marsh of the Barbate River stations and CB2 station in the Bay of Cádiz were the most altered, whereas those at CB5 and CB3 in the Bay of Cádiz were slightly altered, relative to stations CB1 and CB4 in the Bay of Cádiz. A different methodology to calculate the ratio-to-reference and each composite SQT index value is proposed by adding to the classical normalization by using the reference clean station as a new normalization that includes a reference polluted station to establish a between-the-maximum and minimum level obtained in the area studied. We propose this new methodology to calculate weighted results based on the fact that they are obtained using two points of reference for comparison. The results show that sediment pollution is restricted to the vicinity of one untreated sewage discharge in the Bay of Cádiz.
Uptake and bioconcentration of atrazine by selected freshwater algae
Authors: Tang Jixin , Hoagland Kyle D , Siegfried Blair D
Published: March 2010

Atrazine bioconcentration and uptake were determined for eight freshwater green algae and diatoms. Atrazine uptake was extremely rapid in all species examined, with nearly 90% of total uptake occurring within the first hour of exposure. Within each division, different species had different bioconcentration capacities, although the accumulation of atrazine was consistently higher in green algae (5.43–12.73 ng/mg) than in diatoms (0.33–1.69 ng/mg). Atrazine concentrations in the algal cells were much higher than in the medium, although the total amount of atrazine taken up by algae was small relative to the total atrazine in solution (1–3%). The ability of algal cells to accumulate atrazine was highly correlated with algal cell biovolume and surface area, and a strong relationship was observed between sensitivity to atrazine and bioconcentration, cell biovolume, and surface area. In general, higher bioconcentration factors were associated with increased atrazine sensitivity.
Toxicity of emamectin benzoate to mallard duck and northern bobwhite quail
Authors: Chukwudebe Amechi C , Beavers Joann B , Jaber Mark , Wislocki Peter G
Published: March 2010

Nineteen- to 26-week-old mallard ducks (Anas platyrhynchos) were found to be more sensitive than northern bobwhite quail (Colinus virginianus) of the same age to single oral doses of emamectin benzoate. The resulting median lethal dose values determined for emamectin benzoate to mallard duck and northern bobwhite quail were 76 and 264 mg/kg, respectively, and the no-observed-effect levels were <25 and 25 mg/kg, respectively. Exposure of 10-d-old mallard ducks and bobwhite quail to emamectin benzoate in feed also gave relatively high median lethal concentration (LC50) values of 570 and 1,318 ppm, respectively, and no-observed-effect concentrations of 20 and <125 ppm, respectively. Clinical signs of toxicity included lethargy, ruffled appearance, loss of righting reflex, and reduction in food consumption; these signs appeared to be fully reversible with cessation of exposure. The maximum residue level of emamectin benzoate found in field-treated foliage is several-fold (7,125–16,475) less than these LC50 values. Because the likely primary route of emamectin benzoate exposure to birds is through treated food in the diet, these results indicate minimal acute risk to avians from emamectin benzoate use in crop protection.
Ecological risk assessment of copper and cadmium in surface waters of Chesapeake Bay watershed
Authors: Hall Lenwood W , Scott Mark C , Killen William D
Published: March 2010

This ecological risk assessment was designed to characterize risk of copper and cadmium exposure in the Chesapeake Bay watershed by comparing the probability distributions of environmental exposure concentrations with the probability distributions of species response data determined from laboratory studies. The overlap of these distributions was a measure of risk to aquatic life. Dissolved copper and cadmium exposure data were available from six primary data sources covering 102 stations in 18 basins in the Chesapeake Bay watershed from 1985 through 1996. Highest environmental concentrations of copper (based on 90th percentiles) were reported in the Chesapeake and Delaware (C and D) Canal, Choptank River, Middle River, and Potomac River; the lowest concentrations of copper were reported in the lower and middle mainstem Chesapeake Bay and Nanticoke River. Based on the calculation of 90th percentiles, cadmium concentrations were highest in the C and D Canal, Potomac River, Upper Chesapeake Bay, and West Chesapeake watershed. Lowest environmental concentrations of cadmium were reported in the lower and middle mainstem Chesapeake Bay and Susquehanna River. The ecological effects data used for this risk assessment were derived primarily from acute copper and cadmium laboratory toxicity tests conducted in both fresh water and salt water; chronic data were much more limited. The 10th percentile (concentration protecting 90% of the species) for all species derived from the freshwater acute copper toxicity database was 8.3 μg/L. For acute saltwater copper data, the 10th percentile for all species was 6.3 μg/L copper. The acute 10th percentile for all species in the freshwater cadmium database was 5.1 μg/L cadmium. The acute 10th percentile for all saltwater species was 31.7 μg/L cadmium. Highest potential ecological risk from copper exposures was reported in the C and D Canal area of the northern Chesapeake Bay watershed. Relatively high potential ecological risk from copper exposure was also reported in Middle River. Moderate potential ecological risk from copper exposure was reported in selected locations in the Choptank and Potomac Rivers. Potential ecological risk from copper exposure was either low or data were insufficient to assess ecological risk in the other 14 basins. Potential ecological risk from cadmium exposures was much lower than for copper. Highest potential ecological risk from cadmium exposure was reported in the C and D Canal. Low to moderate potential ecological risk for the most sensitive trophic group (fish) was reported in the Potomac River, upper mainstem bay, West Chesapeake watershed, Choptank River, and Chester River. In the other 12 basins, ecological risk was either judged to be low or insufficient data were available for determining risk.
Tiered aquatic risk refinement: Case study—at-plant applications of granular chlorpyrifos to corn
Authors: Havens Patrick L , Cryer Steven A , Rolston Laurie J
Published: March 2010

The tools of risk assessment are important in the management of environmental risk from the use of agricultural chemicals. A tiered process of estimating and refining the risks from runoff to nontarget aquatic ecosystem is described. The methodology uses screening tools at the lower level of assessment and progresses to a probabilistic, geographically specific tool at the highest tier level. The tools are demonstrated by an analysis of the risks to aquatic ecosystems resulting from the use of granular chlorpyrifos on corn. Vegetative filter strips and reduced tillage were examined as potential best management practices to reduce runoff impact. In addition, data from outdoor microcosm experiments were used to refine toxicity endpoints. The combination of runoff reduction and endpoint refinement resulted in a two- to 16-fold reduction in potential risk, based on 90th percentile endpoints. The results also located where more localized efforts in product stewardship, user education, potential field research, or more refined assessment may be beneficial. The simulation results are compared to field monitoring results.
Response of soil microbial biomass to 1,2-dichlorobenzene addition in the presence of plant residues
Authors: Meharg Andrew A , Wyatt Clare L , Thompson Ian P , Bailey Mark J , Ellis Richard J , Maguire Nicola
Published: March 2010

The impact of 1,2-dichlorobenzene on soil microbial biomass in the presence and absence of fresh plant residues (roots) was investigated by assaying total vital bacterial counts, vital fungal hyphal length, total culturable bacterial counts, and culturable fluorescent pseudomonads. Diversity of the fluorescent pseudomonads was investigated using fatty acid methyl ester (FAME) characterization in conjunction with metabolic profiling of the sampled culturable community (Biolog). Mineralization of [14C]1,2-dichlorobenzene was also assayed. Addition of fresh roots stimulated 1,2-dichlorobenzene mineralization by over 100%, with nearly 20% of the label mineralized in root-amended treatments by the termination of the experiment. Presence of roots also buffered any impacts of 1,2-dichlorobenzene on microbial numbers. In the absence of roots, 1,2-dichlorobenzene greatly stimulated total culturable bacteria and culturable pseudomonads in a concentration-dependent manner. 1,2-Dichlorobenzene, up to concentrations of 50 μg/g soil dry weight had little or no deleterious effects on microbial counts. The phenotypic diversity of the fluorescent pseudomonad population was unaffected by the treatments, even though fluorescent pseudomonad numbers were greatly stimulated by both roots and 1,2-dichlorobenzene. The presence of roots had no detectable impact on the bacterial community composition. No phenotypic shifts in the natural population were required to benefit from the presence of roots and 1,2-dichlorobenzene. The metabolic capacity of the culturable bacterial community was altered in the presence of roots but not in the presence of 1,2-dichlorobenzene. It is argued that the increased microbial biomass and shifts in metabolic capacity of the microbial biomass are responsible for enhanced degradation of 1,2-dichlorobenzene in the presence of decaying plant roots.
Estimating the oral bioavailability of methylmercury to channel catfish (Ictalurus punctatus)
Authors: McCloskey John T , Schultz Irvin R , Newman Michael C
Published: March 2010

In classical pharmacology, oral bioavailability of a toxicant is defined as that fraction of an orally administered dose reaching the systemic circulation of the animal. The present study estimates the bioavailability of methylmercury in channel catfish (Ictalurus punctatus) by comparing concentrations in the blood through time after oral and intra-arterial (IA) administration. Catfish were cannulated in the dorsal aorta and gavaged a pelleted feed that had been spiked with methylmercury. Each catfish was gavaged an increasing amount of spiked feed. Following oral dosing, serial blood samples were removed for more than 1,500 h. One month after removal of the last blood sample, the same fish were injected IA with methylmercury and serial blood samples were removed for more than 3,000 h. The area under the curve of the blood concentration-time curve extrapolated to infinity (AUC0→∞) was calculated from fish dosed orally and IA using both noncompartmental (trapezoidal) and compartmental methods. Bioavailability was estimated as the ratio of the dose-corrected oral AUC0→∞ to the IA AUC0→∞. Average bioavailability estimates from this approach were 33% using noncompartmental (range 14–55%) and 29% using compartmental (range 12–42%) methods and were correlated with the amount of food gavaged to the fish (r2 = 0.95, p = 0.026). Bioavailability estimates using the present methods were much lower than estimates using more conventional methods (i.e., assimilation efficiency estimates using mass balance), suggesting that conventional methods may overestimate the true bioavailability of toxicants in fish.
Assessment of sediment toxicity and chemical concentrations in the San Diego Bay region, California, USA
Authors: Fairey Russell , Roberts Cassandra , Jacobi Michele , Lamerdin Stewart , Clark Ross , Downing James , Long Edward , Hunt John , Anderson Brian , Newman John , Tjeerdema Ronald , Stephenson Mark , Wilson Craig
Published: March 2010

Sediment quality within San Diego Bay, Mission Bay, and the Tijuana River Estuary of California was investigated as part of an ongoing statewide monitoring effort (Bay Protection and Toxic Cleanup Program). Study objectives were to determine the incidence, spatial patterns, and spatial extent of toxicity in sediments and porewater; the concentration and distribution of potentially toxic anthropogenic chemicals; and the relationships between toxicity and chemical concentrations. Rhepoxynius abronius survival bioassays, grain size, and total organic carbon analyses were performed on 350 sediment samples. Strongylocentrotus purpuratus development bioassays were performed on 164 pore-water samples. Toxicity was demonstrated throughout the San Diego Bay region, with increased incidence and concordance occurring in areas of industrial and shipping activity. Trace metal and trace synthetic organic analyses were performed on 229 samples. Copper, zinc, mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlordane were found to exceed ERM (effects range median) or PEL (probable effects level) sediment quality guidelines and were considered the six major chemicals or chemical groups of concern. Statistical analysis of the relationships between amphipod toxicity, bulk phase sediment chemistry, and physical parameters demonstrated few significant linear relationships. Significant differences in chemical levels were found between toxic and nontoxic responses using multivariate and univariate statistics. Potential sources of anthropogenic chemicals were discussed.
Toxicity of endosulfan to aquatic stages of anuran amphibians
Authors: Berrill Michael , Coulson Donna , McGillivray Lise , Pauli Bruce
Published: March 2010

The toxicity of endosulfan insecticide to wood frog (Rana sylvatica) embryos and tadpoles of wood frogs, American toads (Bufo americanus), and green frogs (R. clamitans) was examined in the laboratory. Following exposures to 0.03 to 0.4 mg/L endosulfan for 96 h, sublethal effects and postexposure mortality were assessed. In another experiment, premetamorphic American toad tadpoles (with developing hindlimbs but unerupted front legs) were exposed to 0.3 mg/L endosulfan for 96 h. The exposed wood frog embryos hatched successfully and were morphologically indistinguishable from the unexposed animals at the end of the 10-d postexposure period. However, extensive paralysis of exposed tadpoles of all three species occurred; all but one of the exposures resulted in 100% of the tadpoles experiencing paralysis at some point during the exposure or recovery period. Postexposure mortality of tadpoles was high and occurred at the lowest exposure concentrations (0.041–0.053 mg/L) for each species exposed as 2-week-old tadpoles. Newly hatched American toad tadpoles were more tolerant than tadpoles of the other two species, but no clear species differences in sensitivity of 2-week-old tadpoles was apparent. American toad premetamorphs exposed to endosulfan did not recover from the effects of the exposure. Our results indicate that the aquatic stages of anuran amphibians may be sensitive to levels of the pesticide endosulfan that could reach their habitat by means of direct applications or drift from aerial spraying.
Lethal effects of Mexel® 432 to common carp embryolarval stages in river water: Influence of physicochemical parameters in synthetic ISO water
Authors: Arehmouch Latifa , Tfibel Valérie , Chaillou Catherine , Ghillebaert François , Roubaud Pierre
Published: March 2010

The lethal effects of Mexel® 432, an antifouling agent for industrial water circuits, on common carp embryolarval stages in Moselle and Seine River waters and synthetic water were tested in the laboratory. Diluting Mexel 432 in river water resulted in the disappearance of its lethal effects within a few days. In freshly prepared 3-mg/L solutions, 100% mortality occurred within 1 d in synthetic International Standards Organization (ISO) water, compared to 96 h in Seine River water (10-mg/L solutions). No lethal effect was observed after 7 d of exposure in an 8- to 15-d-old 50-mg/L solution in Moselle River water or in a 2-d-old 10-mg/L solution in Seine River water. Inhibition of Mexel 432 toxicity by river waters was not due to calcium concentration, temperature, or pH, because these factors had a negligible influence on the lethal effects of Mexel 432 in synthetic ISO water (ranges, 0.8–800 mg/L, 15–24°C, and 6.9–9.0, respectively). Aldrich Chemical humic acids immediately suppressed the lethal effects of Mexel 432 with an apparent ratio of 1 to 2 mg Mexel 432/mg humic acids. Also, clays and humic acids immediately reduced the concentration of Mexel 432 in semiquantitative colorimetric dosages.
Reproduction and environmental contamination in tree swallows nesting in the Fox River Drainage and Green Bay, Wisconsin, USA
Authors: Custer Christine M , Custer Thomas W , Allen P David , Stromborg Kenneth L , Melancon Mark J
Published: March 2010

Concentration, accumulation, and effects of polychlorinated biphenyls (PCBs) o nreproduction in tree swallows (Tachycineta bicolor) were studied at four sites in the Fox River drainage and in Green Bay, Lake Michigan, Wisconsin, USA, in 1994 and 1995. Total PCBs in eggs and newly hatched young (mean = 3.01 μg/g wet weight, years and sites combined) and 12-d-old nestlings (mean = 2.34 μg/g wet weight) at two contaminated sites (Kidney Island and Arrowhead) were higher than concentrations at two reference sites (Lake Poygan and High Cliff State Park, years and sites combined, pippers mean = 0.26 μg/g, nestlings mean = 0.01 μg/g). Concentrations of 11 PCB congeners were also higher at contaminated compared to reference sites. Polychlorinated biphenyls (PCBs) accumulated in nestlings at a higher rate (1.34–6.69 μg/d) at contaminated sites compared to reference locations (0.06–0.42 μg/d). Dichlorodiphenyldichloroethylene (DDE) was the only other organochlorine found in all samples; concentrations for all samples averaged ≤0.20 μg/g wet weight. Total PCBs and p,p′-DDE concentrations did not differ among clutches where all eggs hatched, some eggs hatched, and no eggs hatched.
Assessment of surface water quality on three eastern North Carolina golf courses
Authors: Ryals Scott C , Genter Mary Beth , Leidy Ross B
Published: March 2010

The golf course industry has become increasingly aware of potential problems related to pesticide and fertilizer movement from soil into surface water and groundwater. Recently, the industry has started to change application practices and pesticide formulations and to participate in routine monitoring studies. Three southeastern North Carolina golf courses agreed to participate in a surface water quality study to determine the movement of fertilizers and related pesticides into surface waters. All three golf courses have ponds that provide irrigation water, from which samples were collected every two weeks. Each course has a sandy loam soil and adjoins wetlands, saline marshes, or elevated water tables. The data indicate that impact to the surface waters from the courses was minimal. Of the four pesticides (atrazine, chlorothalonil [Daconil®], chlorpyrifos [Dursban®], and 2,4-dichlorophenoxyacetic acid) and two nutrients (nitrogen and phosphate) surveyed, only 16 samples exceeded the U.S. Environmental Protection Agency's health advisory levels. All analyses of the samples collected from the outflows of the courses were below their detectable levels.
Solid-phase test for comparison of degradation rates of synthetic mud base fluids used in the off-shore drilling industry
Authors: Munro Pauline D , Croce Bronwen , Moffat Colin F , Brown Nigel A , McIntosh Alistair D , Hird Simon J , Stagg Ronald M
Published: March 2010

A solid-phase degradation test has been developed to assess the fate in marine sediment of synthetic mud base fluids used in the off-shore drilling industry. The degradation rate of an ester-type drilling fluid was investigated at three nominal concentrations in a fine sand. A naturally occurring triester, olive oil, was used as a positive control and a traditional mineral oil served as an example of a poorly degradable substance. Two synthetic drilling fluids, an ester and a blend of n-alkanes with poly-alpha olefin and linear-alpha olefin, were compared in a mud and a coarse sand to examine the effect of different sediments on degradability. Glass jars, containing marine sediment that had been homogeneously mixed with test fluid, were placed in troughs in a continuous flow of seawater. Periodically, triplicate jars were sacrificed and, following solvent extraction, the concentration of test fluid remaining in the sediment was determined by gas chromatography with flame ionization detection. The test was able to reproducibly distinguish between easily degradable and poorly degradable fluids. The rate of degradation was concentration dependent; the half-life increased as the nominal concentration increased. The ester was more rapidly degraded than the blended synthetic drilling fluid and degradation was slower in sand compared with mud.
Effects of a copper-tolerant grass (Agrostis capillaris) on the ecosystem of a copper-contaminated arable soil
Authors: Boon Gerben T , Bouwman Lucas A , Bloem Jaap , Römkens Paul F.A.M
Published: March 2010

To test how a dysfunctioning ecosystem of a severely metal-polluted soil responds to renewed plant growth, a pot experiment was conducted with soil from an experimental arable field with pH and copper gradients imposed 13 years ago. In this experiment, four pH/copper combinations from this field were either planted with a pH- and copper-resistant grass cultivar or remained fallow. During a 10-week period, the dynamics of the microbial activity and of the abundances of bacteria, protozoa, and nematodes were measured, as were the dynamics of several chemical soil parameters. After 13 years of copper (750 kg copper per hectare) and/or pH stress (6.1® 4.7), which had resulted in severely reduced crop growth, no effects were observed on bacterial numbers, respiration, or protozoan numbers, but bacterial growth (measured as [3H]thymidine incorporation into bacterial DNA) was strongly reduced in the low pH plots, and even more so in low pH plots enriched with copper. Of the organisms, only nematodes were negatively affected under conditions of high copper load at low pH. In these plots, numbers belonging to all feeding categories were strongly reduced. Planting of a copper-tolerant grass variety, Agrostis capillaris L. var. Parys Mountain, resulted within 10 weeks in faster bacterial growth and more protozoa and bacterivorous nematodes in comparison with fallow controls; these effects were markedly strongest in the acidic, copper-enriched soils. During incubation, fungivorous nematodes increased in all treatments, in fallow and in planted pots and in the pots with high-copper, low-pH soil. The results of this experiment suggest that introduction of plant growth is one of the major causes of increased biological activity in acidic contaminated soils (approximately 1.2 times the current EC limits). Planting such soils with metal-tolerant plant species can reestablish the necessary food base to support soil organism growth, and this can lead to numerous positive effects, reversing the loss of soil functions due to the high copper levels under acidic conditions.
Using a triad approach in the assessment of hazardous waste site leaching from a superfund site to an adjacent stream
Authors: Leppanen Christy J , Blanner Pat M , Allan Roger S , Benson William H , Maier Kurt J
Published: March 2010

A triad approach was used in the evaluation of sediment in the Wolf River adjacent to the North Hollywood Dump, a federally listed superfund site. Chemical analyses were done for 18 organochlorine pesticides, 21 polychlorinated biphenyl (PCB) congeners, and 10 metals. Sediment toxicity was evaluated with freshwater invertebrates, Chironomus tentans and Hyalella azteca. Benthic macroinvertebrate diversity and abundance were assessed with a family-level biotic index. Mean Al, Ba, Cd, Cu, Fe, Ni, Pb, and Zn concentrations were significantly higher in sediments collected in the spring. Both spring and fall sediments exhibited toxicity downstream from, adjacent to, and upstream from the dump, with toxicity significantly higher in fall sediments; however, a consistent trend was not observed. Toxicity was typically greater in the fall, and metal concentrations were typically higher in spring sediments, suggesting that metals were not responsible for the toxicity. Sediment-associated organochlorine pesticide and PCB congener concentrations were all below detectable limits, suggesting that these potential contaminants are not contributing to the observed toxicity. No differences were found in benthic macroinvertebrate community structure, which was composed of predominantly pollution-tolerant families, among seasons or river reaches, which appear to be limited by the physical characteristics of the river (e.g., substrate instability, low total organic carbon (<0.6%), and water velocity). Sediments in urban reaches of the Wolf River appear to be degraded; the North Hollywood Dump cannot be isolated as a source of toxicity in this study. In situ testing, sediment toxicity identification and evaluation testing, acid-volatile sulfide analyses, or artificial substrate work would be appropriate to follow.
Effects of heavy metals on benthic macroinvertebrate communities in New Zealand streams
Authors: Hickey Christopher W , Clements William H
Published: March 2010

We performed chemical analyses of heavy metals in water and periphyton, toxicity tests with Daphnia magna and an indigenous mayfly (Deleatidium sp.), and field surveys of benthic macroinvertebrates to estimate the degree of metal pollution in three catchments in the Coromandel Peninsula of New Zealand. Good agreement was found between toxicity tests and measures of benthic community structure, particularly at stations with the highest metal levels. Responses of benthic communities at stations with low or moderate levels of metal contamination were variable and were probably confounded by factors other than heavy metals. Effects of heavy metals on benthic communities in New Zealand streams were similar to those reported for metal-polluted streams in North America and Europe, suggesting that responses to metal contamination are predictable. Abundance and species richness of mayflies, number of taxa in the orders Ephemeroptera, Plecoptera, and Trichoptera, and total taxonomic richness were the best indicators of heavy metals in New Zealand streams. In contrast, the quantitative macroinvertebrate community index (QMCI), a biotic index proposed for assessing effects of organic enrichment in New Zealand streams, could not distinguish between reference and metal-polluted streams. The poor performance of the QMCI was primarily due to incorrect tolerance scores for some taxa to heavy metals. Because of concerns regarding the subjective assignment of tolerance values to species, we recommend that tolerance values for dominant species in New Zealand streams should be verified experimentally in stream microcosms.
Effects of ultraviolet light and methoprene on survival and development of Rana pipiens
Authors: Ankley Gerald T , Tietge Joseph E , DeFoe David L , Jensen Kathleen M , Holcombe Gary W , Durhan Elizabeth J , Diamond Stephen A
Published: March 2010

Recently a suite of relatively specific hindlimb deformities have been observed in several anuran species in North America. These deformities include ectopic and supernumerary limbs and missing limbs, limb segments, or digits. The objective of this study was to assess two stressors hypothesized as responsible for limb malformations in amphibians: methoprene, an insect growth regulator that, through interaction with the retinoic acid signaling system, could possibly cause limb deformities, and ultraviolet (UV) light. Northern leopard frogs (Rana pipiens) were exposed to several different concentrations of methoprene both in the absence and presence of UV light designed to mimic the UV wavelength spectrum present in sunlight. Exposures were initiated at early embryonic stages (newly fertilized eggs) and continued through emergence of the forelimbs of the frogs. At the highest methoprene concentration tested, both in the absence and presence of UV light, severe developmental effects were observed, with all organisms dying within 12 to 16 d of test initiation. However, exposure to the pesticide did not cause limb malformations. Irrespective of methoprene treatment, a very high percentage (∼50%) of animals held under the UV light for 24 d developed hindlimb malformations. These malformations usually were bilateral and sometimes completely symmetrical, and consisted of missing limb segments and missing or reduced digits. A complete proximal to distal representation of the deficiencies occurred, ranging from missing or malformed femurs to the absence of single digits or digit segments. The developmental period of greatest sensitivity to UV light occurred during very early limb bud development, corresponding with formation of the apical ectodermal ridge. The significance of these findings in terms of deformed frogs in the field is uncertain. Although the deformity types observed (i.e., missing limb segments and digits) were similar to those seen in some field specimens, the UV light treatment did not cause the full range of malformations observed in animals from the field (e.g., supernumerary limbs, nonbilateral deformities). Furthermore, although the artificial light spectrum utilized mimicked the relative UV spectrum present in sunlight, it did not match full sunlight intensity, and did not accurately mimic visible wavelengths. Finally, the relationship of the UV light dose used in the laboratory to that actually experienced by amphibians in the field is uncertain. Despite these questions, our findings suggest that UV light should be further considered as a plausible factor contributing to amphibian malformations in field settings.
Traditional multivariate techniques: Potential for use in ecotoxicology
Authors: Sparks Tim H , Scott W Andy , Clarke Ralph T
Published: March 2010

This paper summarizes established multivariate techniques and illustrates examples of their use with ecotoxicological data. Multivariate analysis can be broken down into three main areas of application: ordination, clustering/discrimination, and investigating relationships between sets of variables. Many of these techniques are well established, having been developed in the first half of this century. Although some multivariate techniques predate the very familiar analysis of variance (ANOVA), the popularity of multivariate analysis in ecotoxicology is currently overshadowed by ANOVA and regression techniques. We suggest that this will become increasingly less the case and that we can expect to see much greater use of multivariate techniques in ecotoxicology in the future.
Parental exposure to ortho, para-dichlorodiphenyltrichloroethane impairs survival skills of atlantic croaker (Micropogonias undulatus) larvae
Authors: Faulk Cynthia K , Fuiman Lee A , Thomas Peter
Published: March 2010

Three behavioral assays were used to investigate the effect of parental exposure to ortho, para-dichlorodiphenyltrichloroethane (o, p′-DDT, 2.0 or 10.0 μg per 100 g fish per day in the diet for 1 month) on the behavior of Atlantic croaker, Micropogonias undulatus, larvae. Responses to separate visual and vibratory stimuli, as well as routine swimming activity, were quantified using motion analysis equipment. Eggs collected immediately after spawning from adults administered the 2.0 and 10.0 μg per 100 g fish per day doses of DDT contained 0.016 ± 0.002 and 0.049 ± 0.002 μg DDT per egg, respectively. Of the behavioral variables examined, proportion of larvae responding to a vibratory stimulus, burst and routine swimming speeds, active duration, and pause duration were most affected by parental exposure to o, p′-DDT. Mean and maximum burst speeds in response to the visual stimulus were higher for control larvae. The proportion of larvae responding to the vibratory stimulus was significantly higher for control larvae only after yolk and oil globule absorption. Effects of DDT exposure on routine swimming activity were only observed prior to complete oil globule absorption. Changes in these variables due to parental exposure may decrease a fish's chance of survival by increasing predation rates and/or decreasing feeding rates.
Health status and relative exposure of mule deer and white-tailed deer to soil contaminants at the rocky mountain arsenal
Authors: Creekmore Terry E , Whittaker Donald G , Roy Richard R , Franson J Christian , Baker Dan L
Published: March 2010

We evaluated the health of 18 radio-collared deer [13 mule deer (Odocoileus hemionus) and 5 white-tailed deer (O. virginianus)] from the Rocky Mountain Arsenal, near Denver, Colorado, USA, a Superfund site contaminated with a variety of materials, including organochlorine pesticides, metals, and nerve gas production by-products. Radio-collared deer were tracked for 1 to 3 years (1989–1992) to identify relative exposure to contaminants based on telemetry locations plotted on grid maps depicting known soil contaminant concentrations. At the end of the study, all animals were in fair or good body condition at the time of necropsy. Mean ages of mule deer and white-tailed deer were 7.4 (range 4–12) and 10.6 years (range 5–17), respectively. At necropsy, tissues were collected from the deer for serology, histopathology, and analysis for eight chlorinated hydrocarbons and two metals. Detectable residues of mercury were found in the kidneys of 10 deer (range 0.055–0.096 μg/g), dieldrin was found in fat (n = 9) (range 0.02–0.72 μg/g), liver (n = 4) (range 0.017–0.12 μg/g), and brain (n = 1, 0.018 μg/g), and DDE was found in the muscle of one animal (0.02 μg/g). Relative exposure estimates derived from telemetry and soil contamination data were correlated with tissue levels of dieldrin (p < 0.001) and mercury (p = 0.05). Two mule deer had severe testicular atrophy, and one of these animals also had antler deformities. The prevalence of antibodies against epizootic hemorrhagic disease serotype 2 was 85%.
Effects of sediment bioturbation by the estuarine amphipodCorophium volutatoron fluoranthene resuspension and transfer into the mussel(Mytilus edulis)
Authors: Ciarelli Silvana , van Straalen Nico M , Klap Vincent A , van Wezel Annemarie P
Published: March 2010

To better understand the effects of bioturbation on partitioning and availability of sediment-bound contaminants to infaunal amphipods and mussels, experiments were carried out with fluoranthene-spiked sediment. Treatments included different densities of the estuarine amphipod, Corophium volutator. Total suspended solids (TSS), particulate organic carbon/particulate organic matter (POC/POM) in overlying water, fluoranthene concentrations in sediment, pore water, overlying water, amphipods, and mussels were measured. Bioturbation significantly increased TSS and POC/POM concentrations in overlying water, and this effect became greater at higher animal density and longer exposure time. Mean total aqueous fluoranthene concentrations increased from 2.40 to 4.1 and 5.45 μg/L in the control, low-density, and high-density treatments, respectively, after 10 d of exposure. The particle-bound fraction of fluoranthene in the overlying water from the high-density treatment was two times higher than that from the low-density treatment. Bioturbation did not affect the partitioning of fluoranthene over suspended solids and water, nor did it affect the concentrations in sediment and pore water. This was illustrated by the constancy of sediment–interstitial water partitioning coefficients (log Koc(iw)), sediment–overlying water partitioning coefficients (log Koc(ow)), and normalized POC–water partitioning coefficients (log Kpoc). Uptake of fluoranthene by filter-feeding mussels (Mytilus edulis) increased linearly with the density of bioturbating amphipods and with exposure time. The difference in concentrations of fluoranthene in mussels between the lowest and highest density of amphipods was more than a factor of two. Our results showed that bioturbation significantly increases TSS concentration in the overlying water and consequently the total aqueous concentration of sediment-bound contaminants, which are subsequently accumulated by filter-feeders. The increased accumulation in mussels, at a more or less constant concentration in the water, demonstrates the importance of bioturbation as a flux phenomenon and its role in the transport of resuspended sediment-bound contaminants to organisms in the aquatic food chain.
Lethality and bioaccumulation of 4-nonylphenol in bluegill sunfish in littoral enclosures
Authors: Liber Karsten , Gangl James A , Corry Timothy D , Heinis Larry J , Stay Frank S
Published: March 2010

Toxicity and bioaccumulation in bluegill sunfish (Lepomis macrochirus) of 4-nonylphenol (NP), a common precursor and degradation intermediate of certain nonionic surfactants, were evaluated in a set of 18 aquatic mesocosms (littoral enclosures) in northeastern Minnesota. Nonylphenol was applied to enclosures every 48 h over a 20-d period (11 applications) at rates of 3, 30, 100, and 300 μg/L. Additional enclosures served as untreated controls. Maximum NP levels in the integrated water column 2 h after each application averaged 5 ± 4, 23 ± 11, 76 ± 21, and 243 ± 41 μg/L over the 11 applications at the 3-, 30-, 100-, and 300-μg/L treatments, respectively. Sixty-one percent of the NP dissipated from the water column within ˜39 h of each application. Estimated survival of stocked juvenile bluegills was significantly reduced at the 300-μg/L NP treatment. No significant effects were noted at the other NP treatments; however, the 100-μg/L enclosure with the highest mean NP concentration (93 ± 39 μg/L) within that treatment had four to nine times more dead bluegills and four to six times fewer bluegills captured at the end of the season than the other two 100-μg/L enclosures (64 ± 23 and 71 ± 32 μg/L) and the controls, suggesting increased mortality in this enclosure. Nonylphenol tissue concentrations in juvenile bluegills collected from enclosures treated with 3 and 30 μg/L NP ranged from 0.01 to 2.94 μg/g wet weight and showed a significant positive relationship with the average measured NP concentration in the water. The mean wet weight nonequilibrium NP bioaccumulation factor was 87 ± 124. There was no relationship between fish lipid content and NP tissue concentration.
Identification of toxic substances in United Kingdom estuaries
Authors: Thomas Kevin V , Thain John E , Waldock Michael J
Published: March 2010

The organic load of bulk water samples, collected from five industrially impacted estuaries, was extracted using solidphase extraction. Where toxicity was demonstrated using a Tisbe battagliai bioassay, a toxicity directed fractionation scheme was applied to isolate causal compounds. To reduce the complexity of the extracts toxicity profiles were obtained following solid-phase fractionation and reverse-phase HPLC. Candidate toxic contaminants were identified by GC-MS. All procedures were evaluated with a series of reference compounds of widely differing polarity. The method was successful in identifying a number of compounds, which traditionally have not been selected for inclusion in monitoring programs, as the probable cause of detrimental environmental effect. The results suggest that chlorinated phenols are a major contributor to poor water quality in the lower reaches of the river Tyne and alkylphenol surfactant metabolites in the river Tees. Other compounds, as yet unidentified, also contribute to poor water quality. It is suggested that the identified compounds should now be surveyed more widely and considered for inclusion in future monitoring programs.