bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of largemouth bass stocking rate on fish populations in aquatic mesocosms used for pesticide research
Authors: Deutsch William G. , Webber E. Cliff , Bayne David R. , Reed Clarence W. 
Published: March 2010

Abstract
From 1988 to 1989, the effects of largemouth bass (Micropterus salmoides Lacepede) stocking rate on bluegill (Lepomis macrochirus Rafinesque) and bass populations were studied in twelve 0.1-ha mesocosms in Alabama. About 240 mature bluegill were stocked in each pond in May, and their reproduction was monitored biweekly from June through September. Bass fingerlings were stocked at rates of 15, 28, and 55 fish per pond (four replicates) in June, and all fish were harvested in February. Mean length, weight, and relative condition of bass and number of young bluegill decreased with increasing stocking rate. Mean weight, growth, and relative condition of adult blue-gill were directly related to stocking rate. A bimodal spawning pattern of bluegill was observed in all treatments, but the second peak was three-fold greater in the high bass rate than in the low. A combination of bass and bluegill in mesocosms offers several advantages over bluegill alone. The medium bass stocking rate is recommended to maintain both fishes in good condition. Alternatively, bass may be crowded to keep bluegill in peak reproductive condition and optimal growth, prevent overcrowding of young bluegill, and reduce predation pressure on invertebrate populations.
The mixing, distribution and persistence of esfenvalerate within littoral enclosures
Authors: Heinis Larry J. , Knuth Michael L. 
Published: March 2010

Abstract
The synthetic pyrethroid insecticide esfenvalerate was applied to the surface of 18 littoral enclosures (5 × 10 m) in a 2-ha pond near Duluth, Minnesota. The insecticide was applied as Asana® 1.9 emulsifiable concentrate (EC) at five nominal concentrations ranging from 0.01 to 5.0 μg/L active ingredient. Two applications were made 30 d apart. Samples of water, sediment, macrophytes, enclosure wall material, and fish were collected and analyzed for esfenvalerate residue. Maximum water concentrations occurred 1 to 3 h after application and rapidly decreased during the next 24 h. At 5.0 μg/L, 90% of the active ingredient was lost from the water column within 24 h and was below the detection limit (0.047 μg/L) within 4 d. A vertical concentration gradient was observed following application, with 95% of the measured esfenvalerate contained in the upper 75% of the enclosure water column 24 h after application. All other components of the pond ecosystem contained measurable amounts of esfenvalerate. Water and sediment, and, to a lesser extent, aquatic vegetation and macrophytes, were important reservoirs for esfenvalerate. Cumulative sorption of esfenvalerate to sediment and enclosure wall material was observed after two successive applications to littoral enclosures.
Ecosystem-level testing of a synthetic pyrethroid insecticide in aquatic mesocosms
Authors: Webber E. Cliff , Deutsch William G. , Bayne David R. , Seesock Wendy C. 
Published: March 2010

Abstract
Twelve 0.1-ha rectangular ponds (mesocosms) were constructed during 1986 and 1987 to test ecosystem-level responses to a pyrethroid insecticide containing esfenvalerate. Treatment consisted of 10 weekly drift and 5 biweekly runoff simulations of formulated esfenvalerate between July 9 and September 17, 1988. Control ponds received only untreated runoff, while low, medium, and high treatments received total loadings of 0.23, 4.1, and 23.3 g active ingredient (a.i.)/ pond. The top vertebrate predator in the mesocosms was bluegill (Lepomis macrochirus). Once adult blue-gill spawned and young fish were present, microcrustaceans declined in number. Following esfenvalerate applications, nauplii in medium- and high-rate ponds underwent further significant reductions, indicating a response to esfenvalerate not observed in control and low-rate ponds. Relative to other treatments, high-rate ponds were found to have significantly increased metabolism and reduced macroinvertebrates following application. Bluegill exhibited no significant differences in population structure among treatments, although 2-cm-size bluegill were missing from high-rate ponds at harvest. Patterns of response emerged in this whole ecosystem test of esfenvalerate. Variation measured among communities was high as is typical of natural ecosystems; however, we suggest that this experiment provided an acceptable way of detecting impacts at both the community and the ecosystem level.
Orientation of sampling grids for determining the extent of wavefront contamination
Authors: Skalski J. R. 
Published: March 2010

Abstract
Traditionally, sampling grids for the detection of hazardous waste plumes are oriented perpendicularly to the direction of the wavefront of the contaminant. When rotated 45° to the direction of the wavefront, square lattices reduce the maximum waste plume that could go undetected and reduce the number of sampling stations. Improved site characterization and reduced sampling costs can both be achieved through this simple modification.
The distribution of relative error of toxicity of herbicides and metals to Arabidopsis
Authors: Shirazi M. A. , Ratsch H. C. , Peniston B. E. 
Published: March 2010

Abstract
Median toxicity end points such as EC50 and LC50 numbers are commonly reported in the literature for summarizing results of a whole test. A median number is frequently accompanied with a statement of error often derived from theoretical and idealized models. Toxicity end points other than EC50 are seldom reported, and the distribution of their error based on real data remains unexplored. More general toxicity estimates—for example, ECX, where X is any percent response—frequently are needed in environmental risk assessment. An analysis of distribution of the standard error (SE) of toxicity ECX for an array of chemicals tested with Arabidopsis shows that ECX errors cannot be extrapolated from EC50 errors. The analysis includes detailed chemical-by-chemical toxicity end points covering the full range of tested concentrations. A generalized relative error distribution is produced from the data, and its utility for research and environmental management is discussed.
Effects of chlorpyrifos on a microecosystem
Authors: Kersting Kees , van Wijngaarden René 
Published: March 2010

Abstract
A recirculating aquatic microecosystem consisting of three subsystems and with a total volume of 7.5 L was used to study effects of the insecticide chlorpyrifos. The three subsystems represent the trophic levels of primary producers (algae), herbivores (Daphnia magna), and decomposers (bacteria on a sand filter). Two of four microecosystems were perturbed with chlorpyrifos 429 d after they were started. All subsystems were monitored weekly for several chemical and biological variables. The response of the systems was followed for 130 d after chlorpyrifos application. An immediate decrease of the Daphnia population could be explained from the mortality observed in single species tests. The population recovered within two weeks. Two weeks after the introduction of chlorpyrifos, the pH in all subsystems dropped by about two units. Concurrent with the pH changes, there were changes in the algal biomass, the Daphnia numbers, and the oxygen concentrations. The pH in the treated systems was comparable to the controls about 90 d after the treatment, but the other variables did not recover. These effects were not predicted by any single-species test and, therefore, represented ecosystem effects.
Radon remediation studies in northern Virginia and southern Maryland
Authors: Mose Douglas G. , Mushrush George W. 
Published: March 2010

Abstract
A three year study of indoor radon in more than 1,000 homes in northern Virginia and southern Maryland was conducted by using three month-exposure alpha-track monitors In a study set of approximately 200 homes, first floor indoor radon concentrations, which most closely ap proximate home exposure levels, averaged slightly more than 3 pC1/L In a study set of approximately 100 homes, radon concentrations in the water supplies were &lt; 10,000 pC1/L, and no evidence was found to indicate that the waterborne radon concentration was related to the airborne radon concentration
In a study set of approximately 100 homes, subslab ventilation was used to reduce indoor radon concentrations Interest in remediation was related to public perception of radon hazard, in that people with indoor radon measurements of &gt;4 pC1/L were more likely to participate in the reme diation phase of the project Subslab ventilation was successful in &gt;90% of the homes in reducing indoor radon from concentrations as high as 30 pC1/L to &lt;4 pC1/L, at least for the entire year of postremediation radon measurements
Uncertainty and sediment quality assessments: I. Confidence limits for the triad
Authors: Alden Raymond W. 
Published: March 2010

Abstract
The Sediment Quality Triad is an approach that has been used in the assessment of anthropogenic degradation of three complementary components of sediment quality sediment chemistry, sediment toxicity, and in situ effects on the benthic biota Triad plots represent one way to summarize the relative impact for each of these components through the display of “ratio-to-reference” (RTR) values on three axes Although environmental managers can readily interpret the patterns on Triad plots, the conventional presentation has no provisions for the display of confidence limits on the RTR indexes An investigation was conducted that employed simulation techniques to determine the effect of the RTR process on the interpretation of Triad plots constructed for single samples and a method for placing confidence limits on the Triad axes The simulations were based on empirical data sets from benthic biological surveys taken in two regions in the port of Hampton Roads, Virginia, which represented “reference” and “impacted” groups for the “in situ effects” component of the Triad The process of making ratios produced highly non-normal (skewed to the left) distributions of RTR values that were not amenable to the development of confidence limits by conventional statistical techniques Furthermore, the RTR approach produced high probabilities of “Type II” errors for at least one of the indexes (species richness) when applied to single samples taken from reference and impacted populations shown a priori to be very significantly different from each other “Bootstrap” simulation techniques produced confidence limits based on data that were “unit deviate standardized” (UDS approach) or standardized to the mean of the reference data (“ratio-to reference mean,” or RTRM, approach) The UDS approach provides equal weight to all variables, whereas the RTRM approach allows a variable displaying a great degree of difference between reference and test data sets to have a more dominating influence on the Triad assessment
Zinc toxicity and its interaction with cadmium in the submerged aquatic macrophyte Lemna Trisulca L
Authors: Huebert David B. , Shay Jennifer M. 
Published: March 2010

Abstract
Lemna trisulca L was grown axenically with a regular replacement of a complete filter-sterilized medium containing various amounts of zinc and/or cadmium Levels of Zn greater than 3 0 to 4 5 μM decreased the multiplication rate The EC50 was estimated at 5 0 μM Zn for final yield and at 14 μM Zn for multiplication rate There was a significant Zn by Cd interaction, increased Zn levels mitigated the inhibitory effect of Cd on the multiplication rate and final yield of Lemna trisulca cultures Increasing the external Zn concentration from 0 08 μM to 3 06 μM decreased Cd uptake, but further increases in the external Zn concentration to 6 12 and 12 2 μM Zn promoted plant uptake of Cd from the medium Uptake of Zn by Lemna trisulca ranged from a low of 0 9 to 2 0 μmol Zn per gram dry weight at 0 08 μM Zn, to a high of 120 to 150 μmol Zn per gram dry weight at 12 2 μM Zn
Analysis and prediction of hydrophobicity parameters of substituted acetanilides, benzamides and related aromatic compounds
Authors: Nakagawa Yoshiaki , Izumi Keiichi , Oikawa Nobuhiro , Sotomatsu Tomoko , Shigemura Masao , Fujita Toshio 
Published: March 2010

Abstract
The partition coefficient P in the 1-octanol/water system was analyzed for a great number of multisubstituted benzenes of ecotoxicological importance consisting of acetanilides, benzamides, nitrobenzenes, and anisoles having various substitution patterns in terms of the Δ log P (log P – log P[unsubstituted benzene]) quantitatively with free energy-related physicochemical substituent parameters. The analyses showed that the stereoelectronic effects of ortho, meta, and para substituents on the relative solvation of individual polar groups capable of hydrogen bonding with the partitioning solvents are very important in determining the variations in the log P value. The effects were additive in the set of complicated multisubstituted benzenes, leading to a correlation equation represented by a linear combination of terms of hydrophobic, electronic, and steric parameters summed up over substituents. It was suggested that the procedure be extended to analyze and predict the log P value of any multiply substituted benzenes.
Aquatic environmental chemistry of 2-(thiocyanomethylthio)benzothiazole and related benzothiazoles
Authors: Brownlee Brian G. , Carey John H. , MacInnis Gordia A. , Pellizzari Ian T. 
Published: March 2010

Abstract
BUSAN 30WB® is an alternative to pentachlorophenol as an antisapstain agent in the lumber industry. The active ingredient is 2-(thiocyanomethylthio)benzothiazole (TCMTB). Because very little information is available in the open literature on the fate of TCMTB in aquatic environments, we wish to report our studies on TCMTB and related benzothiazoles, some of which are potential transformation products of TCMTB. We measured the water solubility and octanol/water partition coefficients of TCMTB, benzothiazole (BT), 2-mercaptobenzothiazole (MBT), and 2-(meth-ylthio)benzothiazole (MTBT). The water solubility of TCMTB at 24°C was 40 mg/L, and the log Kow was 3.12. At pH 8 and 24°C in dilute borax-phosphate buffer, the half-life of TCMTB was 750 h; in seawater (pH 7.8-8.0, 24°C) it was about 740 h. Attempts to measure sediment/water partitioning of TCMTB produced traces of MTBT, presumed to result from biological methylation of MBT released by hydrolysis of TCMTB. MTBT was produced directly from MBT in the presence of sediment. In phosphate buffer, TCMTB readily underwent direct photolysis in sunlight to produce MBT, in about 50% yield, and traces of BT. The photochemistry of MBT, the major photolysis product of TCMTB, was studied in some detail. Sunlight quantum yields of TCMTB and MBT are estimated to be 0.01 and 0.002, respectively. Sunlight photolysis of MBT in phosphate buffer with and without dissolved organic matter and in a natural water led to three products: BT (28-47%), 2-hydroxybenzothiazole (HOBT) (4-5%), and an unidentified product. On the basis of our laboratory and field results, in addition to literature reports on the occurrence of benzothiazoles, we propose a partial pathway for this family of benzothiazoles in aquatic environments. TCMTB and MBT are unlikely to persist or bioaccumulate. Stable end products appear to be BT, MTBT, and 2-hydroxybenzothiazole.
Effects of pH and humus on the availability of 2,2′,4,4′,5,5′-hexachlorobiphenyl-14C in lake water
Authors: Knulst J. C. C. 
Published: March 2010

Abstract
The effects of treatments of lake water with lime and acid on the availability of 2,2′,4,4′,5,5′-hexachlorobiphenyl to aquatic organisms were studied. A closed laboratory system with hexane-filled dialysis bags of two pore sizes was used, in combination with a 14C-labeled PCB isomer and liquid scintillation counting. Although the dialysis concentration factor remained relatively low throughout the experiment, a significant relationship was found between the bioavailability of polychlorinated biphenyl (PCB) and the dissolved organic carbon (DOC) content of the lake water. The availability of PCB was raised by acid and lime treatment for lake water with low DOC content, whereas both treatments lowered the availability of PCB in water from lakes with high DOC content, compared to untreated water. The liming of the lake water did result in a significantly higher bioavailability of hexachlorobiphenyl in five of the 10 tested lakes. The acidification of the lake water had a significant effect on the bioavailability of PCB in some, but not all, of the lakes. The uptake of PCB in the hexane was inversely related to the DOC concentration of the water phase. The pH does influence the bioavailability of PCB in aquatic systems with various concentrations of humus.
A multispecies laboratory microcosm for screening ecotoxicological impacts of chemicals
Authors: Sugiura Katsura 
Published: March 2010

Abstract
Polypeptone, Cu2+ ion, (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), β isomer of 1,2,3,4,5,6-hexachlorocyclohexane (β-HCH), and γ isomer of HCH (γ-HCH) were added to an aquatic microcosm containing green algae (Chlorella and Scenedesmus), a filamentous blue-green alga (Schizothrix), a ciliate protozoa (Cyclidium), two rotifers (Philodina and Lepadella), aquatic oligochaetes (Aeolosoma) and bacteria (five species or more) in the early stages of the succession. With a nutrient (polypeptone) at 100 to 500 ppm and 2,4,5-T at 10 to 100 ppm, some species were eliminated. No such elimination occurred from a copper concentration of up to 0.4 ppm, but the time-dependent changes in community metabolism were shifted from that of the control at the concentrations of 0.3 and 0.4 ppm. The population densities were affected by β-HCH at 0.1 to 3.0 ppm and γ-HCH at 0.01 to 5.0 ppm in the early stage of the succession, but the population densities became closer to those of the control as the succession advanced. However, time-dependent changes in community metabolism were similar to that of the control. The difference in the time-dependent changes in population density and community metabolism with the DDT addition, up to a concentration of 0.5 ppm as compared with the control, was small. It was shown that the effects of chemical agents on the microcosm can be evaluated by measuring the time-dependent changes in population density and community metabolism. Although complete evaluation must await comparative studies based on test results for other compounds, test results for other microcosms containing diverse species, and results of field experiments, it is suggested that this small-scale repeatable microcosm can be used as a tool for screening tests on generic ecosystem-level toxicity.
Groundwater modeling for an NPL risk assessment
Authors: Schuller Teresa A. , Sayko Steven P. , Desalvo Nicholas 
Published: March 2010

Abstract
A risk assessment for this National Priority List (NPL) site evaluated the magnitude of the public health impact, assuming that no remediation had or would occur at a landfill. The purpose of the groundwater modeling effort was to predict future groundwater concentrations after liner failure at a residential well currently using the ground water. A two-dimensional, transient, instantaneous-release, multipoint-source model was used to estimate the groundwater concentration at the residential well for 120 years after the release. A worst-case concentration in ground water was calculated by assuming that no retardation or degradation (chemical or biological) would occur. A more realistic concentration was determined by developing a retardation factor. The modeled groundwater concentrations that were simulated did not exceed standards. If no remediation were to occur and worst-case liner failure did occur, then the population would still not be at an unacceptable risk from consuming impacted ground water as a potable water supply. In reality, the predicted worst-case exposure concentrations are unlikely to be reached, and the population (i.e., few individuals) might not be exposed.
The octanol/water distribution coefficients of methylmercuric species: The role of aqueous-phase chemical speciation
Authors: Faust Bruce C. 
Published: March 2010

Abstract
A model is proposed that quantitatively describes the 1-octanol/water distribution coefficients of methylmercuric species in terms of the 1-octanol/water partition coefficients of each individual methylmercuric species (i.e., CH3HgCl0, CH3HgOH0, and CH3Hg+) and the aqueousphase equilibrium speciation of the methylmercuric species CH3HgCl0, CH3HgOH0, and CH3Hg+.
Response of hepatic mfo activity and plasma sex steroids to secondary treatment of bleached kraft pulp mill effluent and mill shutdown
Authors: Munkttrick K. R. M. , Van Der Kraak G. J. , McMaster M. E. , Portt C. B. 
Published: March 2010

Abstract
The discharge of bleached kraft mill effluent (BKME) into Jackfish Bay, Lake Superior, Canada, has been associated with a number of changes in the physiology and whole organism responses of four fish species. Current studies have been following physiological indicators of BKME impact for evidence of improvement after the installation of a secondary treatment system. Secondary treatment has not been successful in eliminating BKME impacts on hepatic mixed-function oxygenase (MFO) activity in white sucker (Catostomus commersoni) because fish collected from Jackfish Bay after initiation of secondary treatment exhibited similar MFO activity as recorded in samples collected during two previous years. Hepatic MFO activity was also induced in long-nose sucker (Catostomus catostomus), lake whitefish (Coregonus clupeaformis), and lake trout (Salvelinus namaycush) after secondary treatment. However, samples collected two weeks after a planned mill maintenance shutdown showed no MFO induction in long-nose sucker, reduced MFO activity in white sucker, and a reduced impact zone for MFO induction in lake whitefish. A reduction in circulating levels of gonadal sex steroids has also been recorded in fish exposed to primary-treated BKME in Jackfish Bay. In contrast, neither secondary treatment nor mill shutdown was sucessful in eliminating impacts of BKME exposur on levels of testosterone and 17β-estradiol in female white sucker and long-nose sucker. The short duration of MFO induction after shutdown and the peristence of steroid reductions suggest that (a) secondary treatment has not been successful in removing “MFO-active” compounds from BKME, (b) induction is not related to sediment contamination with persistent compounds, (c) the inducing agents are rapidly cleared by fish, and (d) effects on steroids may not be directly related to MFO induction.
DNA adducts detected in muskrats by 32P-postlabeling analysis
Authors: Halbrook Richard S. , Kirkpatrick Roy L. , Bevan David R. , Dunn Bruce P. 
Published: March 2010

Abstract
Bottom-dwelling fish from the southern branch of the Elizabeth River, Virginia, have lesions associated with exposure to environmental contaminants (primarily polycyclic aromatic hydrocarbons [PAHs]) known to be present in that reach of the river. There is concern that other wild species such as the muskrat (Ondatra zibethicus) living in the southern branch may be adversely exposed to these contaminants. DNA adducts were detected by 32P-postlabeling methods in liver tissue of muskrats collected from the southern branch of the Elizabeth River and the Nansemond River, a nearby reference river. There was no significant difference in DNA adduct concentrations in muskrats collected from the two rivers. Ten surface sediment samples collected from the southern branch of the Elizabeth River contained concentrations of 14 PAHs ranging from 1.50 to 4,233.0 ppm dry weight (total PAHs). These concentrations were significantly greater than those detected in five surface sediment samples collected from the Nansemond River (total PAHs ranged from 0.34–0.95 ppm dry weight). This is the first known study utilizing this technique to detect DNA adducts in situ in a wild terrestrial (semiaquatic) mammalian species and the first time that muskrats have been used in 32P-postlabeling analysis.