bluuebunny/crossref_metadata_2025 huggingface dataset:
A global perspective on forest decline
Authors: Mueller-Dombois Dieter
Published: March 2010

—,;Carbon dioxide, the major plant food, is on the rise, but forests on both sides of the Atlantic are known to be declining, and industrial pollution is widely suspected to be the principal cause. However, significant contemporary forest declines also are occurring in several Pacific forests, in areas completely unaffected by industrial pollution. This paper focuses on researched forest declines in the Pacific area (New Zealand, Japan, and the Hawaiian and Galápagos islands), where canopy dieback was found to be a natural aspect of forest dynamics. It then summarizes characteristics of forest decline in central Europe (Czechoslovakia and Germany), where decline relates mostly to anthropogenic causes. Commonalities among the natural causes in the Pacific and anthropogenic causes in the European forests are emphasized through recognition of a third factor complex, the demographic component, which so far has been largely neglected in the European forest decline research. The natural cause complexes identified as demographic, disturbance, and biotic components are placed into a causal hierarchy theory based on cohort senescence. It is suggested that this may serve as a framework for comparative ecosystem research of forest declines at the global level, which includes a consideration of ongoing biotic impoverishment and climate change.
Implications of physiological responses to chronic air pollution for forest decline in the southeastern United States
Authors: Richardson Curtis J. , Sasek Thomas W. , Fendick Edward A.
Published: March 2010

The effects of acidic precipitation and ozone on physiological processes in loblolly pine (Pinus taeda L.) were assessed over time to determine dose-response relationships of cumulative exposure to varying levels of ozone and acid rain in combination. Seedlings of known provenance were grown in open-top field chambers in a clear-cut forest site in Duke Forest in the Piedmont of North Carolina and were exposed to pH 5.2 or 3.5 precipitation and several proportional ozone treatments (0.5-3.0x ambient ozone). No direct effects of acid precipitation on gas exchange and carbon fixation were found. Elevated ozone exposures had strong negative effects on needle abscission and net photosynthesis. Exposure-response relationships for photosynthesis indicated that a threshold level of approximately 100 ppm·h of cumulative ozone exposure (12-h summation) had to be reached before significant inhibition occurred. Results suggest that chronic pollutant exposure over the growing season has direct negative effects on carbon fixation in loblolly pine that can significantly reduce long-term growth potential. Current ambient ozone levels in the southeastern United States could be responsible for an approximate 19% reduction in instantaneous carbon fixation rates in loblolly pine by the end of one growing season. An 80 to 90% decrease in net photosynthesis was found at 2.25 and 3.0x ambient ozone concentrations, levels often found in major cities and surrounding areas in the South.
Regional forest migrations and potential economic effects
Authors: Hodges Donald G. , Cubbage Frederick W. , Regens James L.
Published: March 2010

Increasing mean global temperatures due to rising levels of carbon dioxide and other “greenhouse” gases in the atmosphere could significantly affect the distribution of commercially important forests in North America. Warmer mean annual temperatures and changing precipitation patterns could cause the range of most temperate forests to shift northward. The temperature increases could outpace the ability of forests to adapt, causing considerable stress and mortality to trees in the southern part of their range without a commensurate increase in growth across the expanding range. If realized, these potential biological impacts on forest distribution and health would affect forest management decisions substantially and could adversely impact forest-based economies in the United States. Specific effects on forest management include changes in the methods and costs of fire, insect, and disease protection; greater demands on forest lands for conversion to food production; and uncertain changes in site quality. Such impacts could affect the economic feasibility of forest management substantially. Subsequent impacts of climate change on the forest products sector in the southern United States alone could total $300 million for declining timber volume and resulting pulp and paper yields, and more than $100 million for increased management costs.
Degradation of acetonitrile and biphenyl compounds by a mixed microbial culture
Authors: Chapatwala Kirit D. , Babu G.R.V. , Nawaz Mohamed S.
Published: March 2010

A mixed microbial culture was isolated from an environment contaminated with organic cyanides and polychlorinated biphenyls (PCBs). This mixed culture could utilize acetonitrile as the sole source of carbon and nitrogen, and biphenyl as the sole source of carbon. This mixed culture also utilized nitriles, their respective amides, and several PCBs as growth substrates. Studies involving the radiolabeled compounds indicated that nearly 70% of [14C]acetonitrile and 51% of [14C]biphenyl were recovered as 14CO2. The end products resulted during the degradation of acetonitrile and biphenyl were identified as ammonia and benzoate, respectively. It was also observed that the mixed culture that can degrade biphenyl loses its capability when transferred repeatedly into a medium supplemented with acetonitrile as growth substrate. The present study suggests that the application of mixed rather than pure microbial culture is more effective in bioremediation of toxic chemicals.
Adaptation of periphytic communities in model streams to a quaternary ammonium surfactantt
Authors: Schwab Burney S. , Maruscik Dorothy A. , Palmisano Anna C. , Ventullo Roy M.
Published: March 2010

The ability of periphytic communities to mineralize the quaternary ammonium surfactant dodecyltrimethylammonium chloride (C12TMAC) was studied in model streams receiving river water amended with 10% final effluent from a sewage treatment plant. In August 1989, clay substrata were placed in each streambed and allowed to colonize with periphyton for three weeks. Subsequently, three streams were continuously dosed with 50, 250, or 1,250 μg/L C12TMAC for an eight-week period, while a fourth stream served as an undosed control. Before dosing, half-lives for mineralization of radiolabeled C12TMAC by periphyton from the model streams were approximately 5 d, and C12TMAC turnover times were >3,000 h. After dosing with surfactant, mineralization half-lives for C12TMAC by periphyton decreased to 0.03 d within four weeks, and turnover times declined to 6 h within six weeks. By contrast, half-lives for mineralization of C12TMAC by periphyton in the untreated control stream increased from 5 to 29 d, and turnover times remained at >3,000 h during the eight-week test period. Results from a similar experiment conducted during the spring of 1990 confirmed a rapid adaptation of periphytic communities to C12TMAC. This study demonstrated that periphytic communities adapted to and mineralized C12TMAC upon exposure under simulated in situ conditions.
Variation in the bioavailability of polycyclic aromatic hydrocarbons to the Amphipod diporeia (SPP.) with sediment aging
Authors: Landrum Peter F. , Eadie Brian J. , Faust Warren R.
Published: March 2010

The accumulation kinetics of the amphipod Diporeia sp. for sediment-sorbed polycyclic aromatic hydrocarbon (PAH) congeners were measured where the contact time between the PAH congeners and the sediments varied between 3 and 150 d. Diporeia were exposed to a reference sediment dosed with two radiolabeled PAHs (phenanthrene and pyrene) and to sediments dosed with the two radiotracers and a mixture of PAHs at 272.3 ® 10.9 nmol g−1 dry sediment, as the sum of the nine nonlabeled PAHs. The sediments were prepared by dosing aliquots of a single collection of sediment with PAHs at different times, producing a series of contact times. The exposures were all performed at the same time from a single collection of organisms. Diporeia were sampled for mortality and toxicokinetics for up to 28 d. Some sediment avoidance was observed during the first 12 d of exposure. The partitioning between sediment particles and interstitial water increased significantly for both phenanthrene and pyrene as contact time increased. The uptake rate coefficient decreased for both phenanthrene and pyrene when the contact with the sediment was increased from 3 to 60 d. When the contaminant-sediment contact was increased from 60 to 150 d, the phenanthrene uptake rate coefficient remained constant whereas that for pyrene increased somewhat. Similar uptake results were observed with the nonradiolabeled compounds.
Surfactants at low concentrations stimulate biodegradation of sorbed hydrocarbons in samples of aquifer sands and soil slurries
Authors: Aronstein Boris N. , Alexander Martin
Published: March 2010

A study was conducted of the effect of two nonionic surfactants on the biodegradation of phenanthrene and biphenyl sorbed to aquifer material and soil. Alfonic 810–60 and Novel II 1412–56 at 10 and 100 μg/ml enhanced the extent of desorption of phenanthrene and biphenyl from aquifer solids, but concentrations of 1 μg/ml or lower were ineffective. The surfactants at 10 and 100 μg/g of aquifer solids enhanced the mineralization of phenanthrene sorbed to the solids, but the extent of mineralization was low. The addition of N and P to aquifer solids with the surfactants did not stimulate the biodegradation. Inoculation of aquifer solids with phenanthrene- or biphenyl-utilizing microorganisms stimulated the rate and extent of mineralization of the two compounds, and the rate was further increased by either surfactant. The rate and extent of phenanthrene and biphenyl mineralization in soil slurries was increased by either surfactant at 10 or 100 μg/g of soil. We suggest that surfactants at low concentrations may be useful for the bioremediation of sites contaminated with sorbed aromatic hydrocarbons.
Identification of surfactants as toxicants in a primary effluent
Authors: Ankley Gerald T. , Burkhard Lawrence P.
Published: March 2010

A partial toxicity identification evaluation (TIE) was conducted with a publicly owned treatment works (POTW) effluent that received no secondary treatment. The effluent was consistently acutely toxic to fathead minnow (Pimephales promelas) and the cladoceran Ceriodaphnia dubia. Initial Phase I toxicity characterization and Phase II identification work with Ceriodaphnia dubia suggested that surfactants were responsible for a significant portion of the toxicity of the effluent. Subsequent experiments concerning the behavior of various mixtures of surfactants in Phase I and Phase II TIE procedures provided additional evidence that these compounds were important determinants of toxicity of the POTW effluent. Finally, measurement of two general classes of surfactants in the test effluent (anionic, nonionic) indicated that there were sufficient concentrations of these compounds to be of toxicological concern. The identification of surfactants as potentially important toxicants in a primary effluent is not particularly surprising in light of their concentrations in untreated or inadequately treated wastewater.
The effect of wood species composition on the toxicity of simulated mechanical pulping effluents
Authors: O'Connor B. I. , Kovacs T. G. , Voss R. H.
Published: March 2010

A series of simulated mechanical pulping (SMP) effluents, prepared from wood species commonly employed in Canada, were analyzed for wood extractives and tested for acute toxicity to fathead minnows (Pimephales promelas) and acute/chronic toxicity to Ceriodaphnia affinis. The acute and chronic toxicities of the SMP effluents were found to vary substantially for the studied wood species. According to wood species, the acute lethal toxicity of the SMP effluents to both fathead minnows and Ceriodaphnia was found to follow the order white pine > balsam fir > hemlock > black spruce > aspen. The chronic effects of the various SMP effluents on Ceriodaphnia reproduction followed the order balsam fir > hemlock > white pine ˜ black spruce ˜ aspen. The effluent prepared from balsam fir exhibited the lowest chronic toxicity threshold, affecting Ceriodaphnia reproduction at concentrations as low as 0.005%. The compound primarily responsible for this effect was identified as dehydrojuvabione, a naturally occurring sesquiterpenoid ester known to be present in balsam fir. Dehydrojuvabione was found to affect Ceriodaphnia reproduction adversely at concentrations as low as 0.5 μg/L.
Effects of forest spraying with two application rates of cypermethrin on food supply and on breeding success of the blue tit (Parus caeruleus)
Authors: Pascual Juan Alberto , Peris Salvador J.
Published: March 2010

A field study was carried out in the springs of 1988 and 1989 in deciduous oak forests of west-central Spain to assess the effects of two aerial sprayings with two different application rates of Cypermethrin, a synthetic pyrethroid, on several reproductive parameters (nest abandonment, nest success, clutch size, hatching success, nestling mortality, daily survival rate, and nestling weight) of the blue tit (Parus caeruleus). These variables were analyzed according to reduction of arthropod density in canopy trees after treatments and results were compared with a control plot (plot A) without application. The plot sprayed in 1988, with a dust formulation of cypermethrin at 75 g active ingredient (a.i.) per hectare (plot B), showed a nearly 100% mortality of lepidopteran larvae, the most important food resource for breeding blue tits, as well as for other arthropods. The drop in food supply in this plot coincided with the hatching or early nestling stage of the blue tit population. There were statistically significant differences between the control plot and plot B in nestling mortality, daily survival rate, nest success, and nestling weight. In the treated plot, nestling mortality was 81%, 65% of nests were unsuccessful, and mean nestling weight was 1 g less than that in the control plot. In the control plot, nestling mortality was 6% and all nests were successful. A second plot was sprayed in 1989 with an ultra-low-volume formulation of cypermethrin at 3.75 g a.i. per hectare, reducing 90% of the caterpillars but not affecting the availability of other arthropods. Blue tit nestlings were older than one week at the moment of the spraying. In this plot, nestlings from late nests showed a higher mortality and a lower daily survival rate than those in the control plot, the only statistically significant differences in breeding parameters between the plots. We suggest that the negative effects of cypermethrin spraying on breeding success of the blue tit in both treated plots are due to indirect effects (shortage in prey availability) rather than to direct effects (toxicity).
Polychlorinated biphenyl residues and egg mortality in double-crested cormorants from the great lakes
Authors: Tillitt Donald E. , Ankley Gerald T. , Giesy John P. , Ludwig James P. , Kurita-Matsuba Hiroko , Weseloh D. Vaughn , Ross Peter S. , Bishop Christine A. , Sileo Lou , Stromborg Ken L. , Larson Jill , Kubiak Timothy J.
Published: March 2010

We evaluated the overall potency of polychlorinated biphenyl (PCB)-containing extracts from double-crested cormorant (Phalacrocorax auritis) eggs with an in vitro bioassay system, the H4IIE rat hepatoma cell bioassay. Results from the H4IIE bioassay were strongly correlated with the hatching success of eggs in the colonies, whereas conventional methods of PCB analysis correlated poorly with hatching success of eggs from the same colonies. These observations suggest that even though concentrations of total PCB residues have declined in almost all compartments of the environment, their effects are still being observed. The significance of this observation is that the adverse symptoms presently observed in certain Great Lakes fish-eating waterbird populations do not appear to be caused by some as yet unidentified industrial chemical or chemicals and seem not to be the result of pesticides, but rather to the dioxin-like activity of PCBs. Evidence is presented to suggest that the relative enrichment of the potency of PCBs in the environment may play a role in the persistence of the observed adverse symptoms.
Assessing the relationship between ambient toxicity and instream biological response
Authors: Dickson Kenneth L. , Waller William T. , Kennedy James H. , Ammann Larry P.
Published: March 2010

Robust canonical correlation and classification methods were used to evaluate relationships between ambient toxicity and instream biological response. Ten studies of freshwater aquatic systems were used in the analysis. These studies included eight site studies conducted by the U.S. Environmental Protection Agency's Complex Effluent Toxicity Testing Program, one study by the University of Kentucky and one study by the University of North Texas.

Results from ambient toxicity tests, including Ceriodaphnia neonate production and Pimephales promelas dry weight and survival, were used to predict impact at sampling stations. Instream biological response variables, including fish and benthic richness, were used to classify whether or not a station was impacted. The strength of the relationship between ambient toxicity and instream impact was determined by statistically evaluating agreement between the predicted and observed impacts. Results of the analysis showed that statistically significant relationships between ambient toxicity and instream impact were found in each of the studies.
Attraction of crayfishes Procambarus clarkii, Orconectes rusticus and Cambarus bartoni to a feeding stimulant and its suppression by a blend of metals
Authors: Steele Craig W. , Strickler-Shaw Shari , Taylor Douglas H.
Published: March 2010

Preference/avoidance responses and alterations in locomotor activity of adult intermolt crayfishes were examined in response to a blend of copper, chromium, arsenic, and selenium; to a feeding stimulant; and to mixtures of the feeding stimulant and the metals blend. The proportion of metals in the blend simulated that found in a typical fly ash slurry from a coal-fired electric plant (Cu:Cr:As:Se, 1.00:0.54:1.85:0.38). Two experimental series were used in the bioassay. In experimental series 1, preference/avoidance responses of crayfishes placed into an octagonal fluviarium were determined for the blend of metals infused into one octant of the arena at concentrations of either 20 or 2% of the average concentration found in the fly ash slurry. Preference/avoidance responses of the animals to the feeding stimulant, and to combined mixtures of the feeding stimulant and the metals blend, were similarly determined. All species exhibited a preference response to the feeding stimulant, but none of the species exhibited a preference or avoidance of either concentration of metals blend. Both concentrations of metals blend suppressed the preference response to the feeding stimulant in Procambarus clarkii and Orconectes rusticus; Cambarus bartoni exhibited a preference to the feeding stimulant in the presence of both concentrations of the metals blend. Experimental series 2 repeated the presentations of metals blend and feeding stimulant plus metals blend mixtures to the crayfishes, but with the metals blend infused into all octants of the fluviarium and the mixtures of feeding stimulant plus metals infused into one octant only. This second experimental protocol is believed to better simulate an encounter of chemical conditions by crayfishes in nature. Results indicated no preference for or avoidance of the feeding stimulant plus metals blend mixtures by any species at either concentration of metals blend.
Brain and bone aluminum: A comparison of aluminum intake in rats
Authors: Nicar Michael J. , McIntire Donald D. , Pak Laura K.
Published: March 2010

Serum and bone aluminum concentrations were significantly higher in young rats fed pharmacological doses of aluminum for 29 d than in control rats that did not receive extra aluminum. The control rats had a serum aluminum level of 18 ± 3 (SE) ppb and a bone aluminum level of 19.1 ± 1.0 ppm; the aluminum-exposed rats had a serum aluminum level of 44 ± 7 ppm and a bone aluminum level of 27.2 ± 2.4 ppm. Rats fed a diet analogous to aluminum-contaminated foods had control levels of serum and bone aluminum. Increases of approximately 1 ppm (over the control level) in brain aluminum concentrations of both dosed groups of rats were not statistically significant. The aluminum intake correlated with serum and bone aluminum concentrations, and the serum aluminum concentrations correlated with the bone aluminum concentrations. However, the concentrations of brain aluminum did not correlate with either aluminum intake or serum aluminum levels.
Vapor-phase partitioning of volatile organic compounds: A regression approach
Authors: Thoms Sharon R. , Lion Leonard W.
Published: March 2010

Partitioning of 15 volatile organic compounds (VOCs) between the vapor phase and dry and moist Al2O3 samples was measured using a headspace technique. The best predictors of partition coefficients (K′p) from the vapor phase varied with the three Al2O3 moisture contents (MCs) used; these variations may reflect alternate sorption mechanisms. For instance, sorption of chlorinated hydrocarbons at 1.9% MC was best explained by the hydrogen bond acceptor parameter β, suggesting hydrogen bonding between the —Cl group and surface groups or water films. However, sorption on humic acid-coated Al2O3 at approximately 45% MC was best explained by the log of the aqueous solubility and Henry's law constant. The importance of aqueous solubility and Henry's law constant suggested that dissolution of organic compounds in interstitial water is a primary sorption mechanism for VOCs at high Al2O3 MCs. Sorption of the relatively insoluble hydrocarbons such as n-alkanes occurred in excess of that explained by dissolution in the interstitial water and may reflect the importance of partitioning into the organic matter provided by the humic acid coating.
Ambient toxicity testing in the Chesapeake Bay watershed using freshwater and estuarine water column tests
Authors: Hall Lenwood W. , Ziegenfuss Michael C. , Fischer Steven A.
Published: March 2010

This study was designed to identify toxic ambient areas in the Chesapeake Bay watershed by using the following three estuarine and two freshwater 8-d water column toxicity tests: sheeps-head minnow, Cyprinodon variegatus, larval survival and growth test; grass shrimp, Palaemonetes pugio, larval survival and growth test; copepod, Eurytemora affinis, life cycle test; fathead minnow, Pimephales promelas, larval survival and growth test; and Ceriodaphnia dubia, survival and reproduction test. Ambient water was collected from the following locations and transported back to our laboratory for testing: Elizabeth River (VA), Patapsco River (MD), Wye River (MD), and Potomac River (three freshwater and two saltwater stations). The Potomac River stations were located at Indian Head (MD), Freestone Point (VA), Possum Point (VA), Morgantown (MD), and Dahlgren (VA). A suite of inorganic and organic contaminants and water quality conditions were evaluated in ambient water during the tests. Results from the water column tests demonstrated no significant ranking of sensitivity among the three saltwater tests, but rather supported the need for multispecies tests because different species displayed varying sensitivity to different types of contaminants. Biological effects were reported from at least one test species tested in ambient water from Elizabeth River, Patapsco River, Indian Head, Morgantown, and Dahlgren. These results demonstrate that selected ambient areas of the Chesapeake Bay watershed are toxic, based on various biological indicators.
Interclonal variation in the performance of Daphnia magna straus in chronic bioassays
Authors: Soares Amadeu M. V. M. , Baird Donald J. , Calow Peter
Published: March 2010

As an ecotoxicological test organism, Daphnia magna Straus has a long history and is now used extensively. Despite this, considerable variation in interlaboratory bioassays using the same reference toxicant has been reported. Using a standard quantitative genetics approach, the relative tolerance of different genotypes of Daphnia magna to two toxicants (sodium bromide and 3,4-dichloroaniline) was assessed. As expected, the environmental component of variability dominated the chronic response with a significant component of interaction. Differences between genotypes, although significant, were not large. It was concluded that genotype-environment interactions played a key role in determining chronic responses of Daphnia magna to both compounds. Some suggestions are given to improve the level of repeatability in Daphnia magna bioassays.
A statistical procedure for modeling continuous toxicity data
Authors: Bruce Robert D. , Versteeg Donald J.
Published: March 2010

Chronic aquatic toxicity test results are commonly analyzed with statistical hypothesis tests to generate summary statistics known as the no-observed-effect concentration (NOEC) and first-observed-effect concentration (FOEC). These procedures address statistical differences among treatments but suffer several critical limitations. Use of concentration-response statistics to estimate minimal effect concentrations (i.e., EC values) from quantal and continuous data has advantages over a hypothesis-testing approach for generating a biologically relevant end point and an estimate of variability from toxicity tests. Estimation of the concentration-response statistic (EC, effective concentration) for continuous data is not straightforward but is possible with a variety of approaches. A statistical method for estimating EC values described here is based on a nonlinear regression estimation procedure. The usefulness of this method is demonstrated with continuous data from chronic toxicity tests with algae, fish, and invertebrate populations.
Sediment bioassessment in Halifax Harbour
Authors: Tay Kok-Leng , Doe Kenneth G. , Wade Suzanne J. , Vaughan David A. , Berrigan Rita E. , Moore Michael J.
Published: March 2010

Halifax Harbour sediments contain heavy metals and organic contaminants. To assess the biological effects of these compounds in the sediment, seven sites spanning a range of known sediment types, water depths, metal levels, and organic contaminant levels were chosen for assessment by a series of tests. Sediment toxicity was measured by the reduction of microbial luminescence (Photobacterium phosphoreum) in three Microtoxr̀ tests (pore water, solvent extract, and solid phase), by the percentages of survival and reburial in two amphipod species (Rhepoxynius abronius and Corophium volutator), and by the survival and change in biomass of juvenile polychaete (Neanthes sp.). Uptake of contaminants from sediment was assessed by a bioaccumulation test, using a bivalve mollusc (Macoma balthica). The chronic effects of the sediment on bottom-dwelling fish were assessed by histopathological studies on winter flounder (Pseudopleuronectes americanus) collected from the harbor. The results of this study showed detectable biological effects of the Halifax sediments on two (Photobacterium phosphoreum and Rhepoxynius abronius) of the four species of tested organisms. These effects were associated with high concentrations of polynuclear aromatic hydrocarbons (PAHs) in the harbor sediments. The order of sensitivity for the various sediment toxicity tests was Microtox solvent extract = Microtox solid phase > Rhepoxynius abronius > Microtox pore water > Corophium volutator = Neanthes sp. Mortality in Macoma was increased, although no significant uptake of contaminants was detected in the bioaccumulation test. Hepatic lesions were observed in winter flounder collected from the harbor, suggesting a chronic effect of the contaminated harbor sediment.
Effects of fenitrothion on survival, behavior, and brain cholinesterase activity of white-throated sparrows (Zonotrichia albicollis)
Authors: Forsyth Douglas J. , Martin Pamela A.
Published: March 2010

White-throated sparrows (Zonotrichia albicollis) were fed six concentrations of dietary fenitrothion (0, 25, 40, 60, 90, and 200 ppm) for 5 d to determine effects on survival, behavior, and brain cholinesterase (ChE) activity. Each bird was observed for 5 min/d for 5 d before, during, and 3 d after exposure, and activities were categorized. Brain ChE activity of birds dying during exposure and of birds surviving 3 d after exposure was measured. The 5-d LC50 was 49.8 ppm, with 100% mortality occurring in the 90- and 200-ppm groups. All birds dying during the exposure period had brain ChE activities depressed more than 2 sd below control activity, and level of inhibition was positively related to dietary concentration (p = 0.04). ChE activities of birds surviving exposure were inhibited from 41 to 58% of control activity. The 25-, 40-, 60-, and 90-ppm groups increased time spent foraging during the exposure period over pretreatment rates, whereas the 200-ppm group showed a decrease. Birds that died during the 5-d treatment period weighed 30% less than survivors. There was also a trend for decreased time spent hopping in all fenitrothion-treated groups. Frequency of singing declined in all groups, including controls, throughout the exposure period and increased slightly during the recovery period. Fenitrothion residues available to birds in spruce bud-worm larvae were only 0.7 to 1.2 ppm wet weight 3 h after aerial application at 210 g active ingredient per hectare.
Use of the stream mayfly Cloeon triangulifer as a bioassay organism: Life history response and body burden following exposure to technical chlordane
Authors: Sweeney Bernard W. , Funk David H. , Standley Laurel J.
Published: March 2010

The stream mayfly Cloeon triangulifer is well suited as a bioassay organism because it has a relatively short egg and larval stage and can be readily cultured under laboratory conditions. Moreover, the species is widely distributed and reproduces as parthenogenetic clones. Nineteen distinct clones have been isolated from natural populations with Nei's genetic distance between clones ranging from 0.004 to 0.183. Clonal reproduction gives research scientists the option of including or excluding genetic variation from the experimental design. The present study involved exposing individuals from a single clone to initial technical chlordane levels ranging between 4.3 and 56.3 μg/L. No effect of chlordane was observed for the egg stage; eggs required 9 d to hatch at 20°C, and >95% of the eggs hatched in all controls and treatments. Egg hatch success was also tested at higher concentrations (89.0 and 158.3 μg/L), with no effect being observed. In contrast, larval survivorship decreased significantly from about 80% for control groups to 18.0 and <0.6% when larvae were exposed to initial chlordane levels of 4.3 μg/L and 9.4 μg/L, respectively. All larvae died when initial concentrations of chlordane were >15.4 μg/L. Sublethal effects on larvae exposed to 4.3 μg/L of chlordane included significantly longer developmental time (37 vs. 34.8 d) and larger adult size (1.5 vs. 1.1 mg) relative to controls. Body burdens of chlordane in adult tissue for individuals reared in the 4.3-μg/L treatment ranged from 51 to 140 ppb. Chlordane-related compounds found in adult mayfly tissue were cis-nonachlor (6%), trans-nonachlor (45%), cis-chlordane (4%), trans-chlordane (5%), oxychlordane (21%), and heptachlor epoxide (18%).
Tributyltin levels in bivalve mollusks from the east and west coasts of the United States: Results from the 1988–1990 national status and trends mussel watch project
Authors: Uhler A.D. , Durell G.S. , Steinhauer W.G. , Spellacy A.M.
Published: March 2010

Three years of extensive monitoring for tributyltin (TBT) and its degradation products in tissue of sentinel bivalve mollusks at 69 East Coast and 42 West Coast sites of the United States suggests that the tissue levels of organotins are decreasing systematically at some sites and remaining static or fluctuating at others. Local effects driving input of TBT and influencing the overall health of the organisms are suggested as responsible for these observations. The ratio of TBT to its principal degradation product dibutyltin (DBT) in bivalve mollusk tissues appears to be species specific and constant over a wide range of butyltin concentrations in the animals. The TBT/DBT ratios (mean ± one standard deviation) were determined for the blue mussel Mytilus edulis (2.6 ± 1.0), the California mussel Mytilus californianus (6.2 ± 4.0), and the Eastern oyster Crassostrea virginica (6.2 ± 3.4).
Determinants of the short-term dynamics of PCB uptake by plankton
Authors: Richer Guylaine , Peters Robert Henry
Published: March 2010

Many studies relate the ecological fate of a contaminant to its chemical structure, but few combine quantitative structure-activity relationships with environmental properties that may modulate those effects, so the modulating role of such properties remains unquantified. This study determines the effects of variations in suspended biomass, dissolved and colloidal organic carbon, and pH on the time course of 2,2′,4,4′,5,5′-hexachlorobiphenyl uptake by laboratory cultures of Selenastrum capricornutum Printz. Variations in pH had no effect, but uptake increased with biomass and decreased at higher levels of organic carbon, measured as absorbance at 440 nm (Abs, per meter). Coefficients for these effects combined with existing relations based on simple first-order molecular connectivity (χ) or capacity ratio (K′) yielded semi-empirical equations to predict the instantaneous rate of uptake and bioconcentration factor (BCF) of organic contaminants: log rate = −3.30 + 0.32χ + 1.1 log biomass - 0.42 log Abs; log BCF = 4.11 + 0.86 log K′ - 0.87 log biomass — 0.22 log Abs. These equations, entirely based on pure laboratory cultures, were assessed by comparing predicted uptake with the time courses of polychlorinated biphenyl (PCB) uptake by plankton in water from 11 Quebec lakes and proved to be more effective than predictions based on contaminant properties alone.
Monitoring organochlorines in blood of sharp-shinned hawks (Accipiter striatus) migrating through the great lakes
Authors: Elliott John E. , Shutt Laird
Published: March 2010

Blood samples from sharp-shinned hawks (Accipiter striatus) were collected from 1985 to 1989 during the fall migration at Hawk Cliff, Ontario, and during the spring migration at Whitefish Point, Michigan, and analyzed for organochlorine contaminants. The study was designed to investigate the potential of using blood samples from birds of prey trapped by banders as a means of estimating the organochlorine exposure of migrant birds on their breeding and wintering grounds. Mean plasma levels averaged over the entire sample were highest for p,p′-DDE (0.28 mg/kg, wet weight), followed by total polychlorinated biphenyls (PCBs) (0.08 mg/kg, wet weight). Mean levels of DDE, mirex, oxychlordane, heptachlor expoxide, dieldrin, hexachlorobenzene, and PCBs increased significantly in hatch-year birds from their first southward migration to their return flight the following spring as second-year birds. Thereafter, mean residue levels of the more persistent chemicals, including DDE, oxychlordane, and PCBs, did not change significantly between seasons in adult age classes. In contrast, dieldrin and heptachlor epoxide, which have a shorter half-time in the body, increased significantly in the blood of all age classes after each winter and decreased significantly after each breeding season. The results were interpreted in terms of the clearance rates of the compounds as well as the diet of the birds on the breeding grounds. The sharp-shinned hawk is a useful indicator species for contaminant-monitoring programs involving birds of prey.
Use of the aquatic oligochaete Lumbriculus variegatus for assessing the toxicity and bioaccumulation of sediment-associated contaminants
Authors: Phipps Gary L. , Ankley Gerald T. , Benoit Duane A. , Mattson Vincent R.
Published: March 2010

In this paper we describe test methods utilizing the aquatic oligochaete Lumbriculus variegatus to assess the acute and chronic toxicity and the presence of bioaccumulatable compounds in contaminated sediments. Lumbriculus variegatus was chosen as a test species because (a) it represents an ecologically relevant component of freshwater ecosystems (i.e., oligochaetes); (b) it is suitable for long-term testing and evaluation of chronic toxicity end points (e.g., growth, reproduction); (c) it is exposed via all important routes of concern, including ingestion of contaminated particles; and (d) it has sufficient biomass to assess bioaccumulation of contaminants. Also, Lumbriculus variegatus is easily cultured and handled. Described herein are culturing procedures and test protocols (e.g., test length, sample size, feeding, etc.) for Lumbriculus variegatus, as well as two examples of the types of experimental data generated when using the oligochaete in tests with contaminated sediments.
Effects of the organophosphate pesticide Counter® on laboratory deer mice (Peromyscus maniculatus)
Authors: Block Elizabeth K. , Kendall Ronald J. , Lacher Thomas E.
Published: March 2010

Laboratory deer mice (Peromyscus manniculatus) received a single oral dose of the organophosphate (OP) pesticide COUNTER® at four dose levels (2.48, 1.69, 0.92, and 0.0 mg active ingredient per kilogram body weight). The animals were sacrificed at 2, 4, 8, 16, 24, 48, and 96 h after dosing to determine brain cholinesterase inhibition and recovery over time. Brain cholinesterase of treated mice was depressed in a dose-dependent fashion but showed no detectable change over time and did not recover over 96 h. Brain cholinesterase measurement is probably not appropriate for determining COUNTER-induced death; mice that died did not have lower cholinesterase activity than sacrificed mice. Brain cholinesterase depression may not be a direct cause of death due to COUNTER exposure. Sublethal effects of exposure at the two highest doses included reduction in food consumption and body weight, and behavioral signs indicating intoxication for at least 24 h after dosing. Residue was detected in only one out of 67 brain tissue samples. Response of brain cholinesterase to COUNTER exposure is atypical relative to other OPs.
Herbicide dissipation studies in southern forest ecosystems
Authors: Michael Jerry L. , Neary Daniel G.
Published: March 2010

Results of research on the movement of hexazinone, imazapyr, picloram, and sulfometuron in first-order watersheds in the southern United States are presented. Herbicides contaminate surface waters to varying degrees, depending on application rate, method of application, product formulation, and site-specific characteristics. Highest concentrations are observed in streams in ephemeral pulses during the first three storm events after application. Streamside management zones greatly reduce the amount of herbicide entering streams from forestry applications. Soil persistence of herbicides is highly variable and a function of many site characteristics. Plant residues have been monitored and found to dissipate rapidly, with half-lives < 40 d.
Fate, dissipation and environmental effects of pesticides in southern forests: A review of a decade of research progress
Authors: Neary Daniel G. , Bush Parshall B. , Michael Jerry L.
Published: March 2010

Ten years of watershed-scale research has been conducted on the fate of forestry-use pesticides in forested catchments under mainly operational conditions throughout the southern United States. Studies have evaluated chemicals such as hexazinone, picloram, sulfometuron methyl, metsulfuron methyl, azinphosmethyl, triclopyr, carbofuran, lindane, malathion, fenvalerate, copper-chromium-arsenic, and pentachlorophenol. Off-site movement in stream flow, leaching to ground water, and thermal combustion have been examined. Model verifications of pesticide fate and dissipation and risk analyses have been conducted using simulation models such as GLEAMS, CREAMS, and PRZM. Field study data indicate that movement is controlled by the main hydrologic pathways (e.g., surface runoff, infiltration, interflow, and leaching below the root zone). Peak residue concentrations tend to be low (< 500 μg/L), except where direct applications are made to perennial streams or to ephemeral channels, and where buffer strips are not used and do not persist for extended periods of time. Indirect effects noted from the use of pesticides in forested watersheds include temporarily increased nitrate nitrogen losses, reduced sediment yields, temporal changes in terrestrial invertebrate abundance, reduced plant diversity, and changes in particulate organic matter transport in streams. Very limited cumulative effects research has been conducted. The effects of increasing watershed size on herbicide concentrations and the impact of nonforestry pesticides on fish have been examined. Analyses conducted in regional environmental impact statements indicate that the low concentrations and short persistence of forestry pesticides in surface and ground water do not pose a significant risk to water quality, aquatic biota, or human health.
FSCBG: An aerial spray dispersion model for predicting the fate of released material behind aircraft
Authors: Teske Milton E. , Bowers James F. , Rafferty James E. , Barry John W.
Published: March 2010

The development of the aerial spray dispersion model FSCBG (Forest Service, Cramer, Barry and Grim) by the USDA Forest Service and the U.S. Army is reviewed. FSCBG predicts the behavior of spray material released through nozzles into the wake of a spray aircraft (helicopter or fixed-wing), traveling through idealized atmospheric effects, penetrating a canopy and depositing on the ground. FSCBG contains simplified models for the complex flow structure behind aircraft and the mechanisms that affect the fate of aerially released material: downwind drift, evaporation, canopy penetration, and ground and canopy deposition. Model development efforts encompass the areas of spray behavior, aircraft wake effects, meteorological influences, canopy interaction, and deposition. These efforts are supplemented by model validation with field tests. The ability of the model to quantify off-target spray drift is particularly important.
Do aquatic effects or human health end points govern the development of sediment-quality criteria for nonionic organic chemicals?
Authors: Parkerton T.F. , Connolly J.P. , Thomann R.V. , Uchrin C.G.
Published: March 2010

The equilibrium partitioning theory may be used to describe the partitioning of nonionic organic chemicals between water, sediment, and aquatic biota. This paradigm was employed to compare the relative magnitudes of organic carbon-normalized sediment-quality criteria that are intended to protect either benthic organisms from the direct toxic effects of sediment-associated chemicals or humans from the indirect health effects posed by the ingestion of contaminated aquatic animals. Comparison of calculated sediment-quality criteria for a variety of hydrophobic chemicals suggests that human health-based end points often result in more restrictive criteria than aquatic effects-based values. Review of published field data indicates that the equilibrium partitioning paradigm may, depending on contaminant class, either over- or underestimate the extent to which sediment associated contaminations are bioaccumulated. Despite the limitations of adopting this simple theory for criteria development, calculations reveal that regulatory decisions involving sediments contaminated with such chemicals may be dictated by human health concerns if current risk assessment methodologies are applied.
Effect of dietary selenium on the reproductive success of bluegills (Lepomis macrochirus)
Authors: Coyle James J. , Buckler Denny R. , Ingersoll Christopher G. , Fairchild James F. , May Thomas W.
Published: March 2010

The effects of dietary and waterborne selenium on the reproductive success of adult bluegills were evaluated in a chronic toxicity study. Before spawning, two-year-old bluegills were exposed for 60 d to six combinations of dietary and waterborne selenium. Mean seleno-L-methionine (as selenium) concentrations measured in the diet were 0.8 (control), 4.6, 8.5, 16.8, and 33.3 μg/g (dry weight). Waterborne selenium was supplied as a 6:1 mixture of selenate and selenite. Nominal waterborne selenium exposure concentration was 10 μg/L in all exposures except the control. Morphological measurements of adult fish, including length, weight, condition factor, and Gonado Somatic Index, were measured at days 60 and 140 of exposure. Reproductive indicators, including spawning frequency, number of eggs per spawn, percentage of hatch, and survival of resulting fry for 30 d after hatch were monitored during the 11-week spawning period. Selenium concentrations were determined in adult fish, eggs, and 30-d-old fry.

Only fry were significantly affected. Survival was severely reduced in fry of parents exposed to 10 μg/L waterborne selenium in combination with dietary exposure of 33.3 μg/g (dry weight) seleno-L-methionine. These results support field observations that indicate food-chain accumulation of selenium can severely reduce reproductive success of bluegills.
Development of a chronic sublethal bioassay for evaluating contaminated sediment with the marine polychaete wormNereis (Neanthes) arenaceodentata
Authors: Dillon Tom M. , Moore David W. , Gibson Alfreda B.
Published: March 2010

Development of a chronic sublethal sediment bioassay with the polychaete Nereis (Neanthes) arenaceodentata is described. The sublethal test end point was estimated individual somatic growth rate (milligrams dry weight per day). The test was initiated with two- to three-week-old post-emergent juvenile worms and continued for 28 d. The potential bias due to selected nontreatment factors on polychaete survival and growth was evaluated. For example, grain size had no significant effect, whereas the number of worms placed in each exposure vessel was critical. Direct transfer from 30%0 seawater to salinites ≤15%0 had a highly significant and adverse effect on survival and growth. Both survival and growth of juvenile worms may be adversely affected if test conditions involve exposures to ≥ 0.7 mg/L un-ionized ammonia or ≥ 5 mg/L hydrogen sulfide. Survival of juvenile worms to concentrations of the reference toxicant, cadmium chloride, approximating the 96-h LC50 (5 mg/L) was used as a quality control measure. Results are expressed in control chart format analogous to methods used in analytical chemistry.