High incidence of deformity in aquatic turtles in the John Heinz National Wildlife Refuge

The John Heinz National Wildlife Refuge is subject to pollution from multiple sources. We studied development of snapping turtle (Chelydra serpentina) and painted turtle (Chrysemys picta) embryos from the refuge from 2000 through 2003. Mean annual deformity rate of pooled painted turtle clutches over four years ranged from 45 to 71%, while that of snapping turtle clutches ranged from 13 to 19%. Lethal deformities were more common than minor or moderate deformities in embryos of both species. Adult painted turtles had a higher deformity rate than adult snapping turtles. Snapping turtles at JHNWR had high levels of PAH contamination in their fat. This suggests that PAHs are involved in the high level of deformities. Other contaminants may also play a role. Although the refuge offers many advantages to resident turtle populations, pollution appears to place a developmental burden on the life history of these turtles.     

Environmental contamination and developmental abnormalities in eggs and hatchlings of the common snapping turtle (Chelydra serpentina serpentina) from the Great Lakes-St Lawrence River basin (1989-1991)

During 1989-1991, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (Chelydra serpentina serpentina). Eggs were collected and artificially incubated from eight sites in Ontario, Canada and Akwesasne/New York, USA. In eggs from the same clutches we measured 20 organochlorine pesticides, 48 polychlorinated biphenyl (PCBs) congeners including 6 non-ortho PCBs, 8 polychlorinated dibenzodioxins (PCDDs), 14 polychlorinated dibenzofurans (PCDFs) and total mercury. We found a significant increase in abnormal development with increasing polychlorinated aromatic hydrocarbon exposure in eggs, particularly PCDD and PCDF concentrations. In contrast, the risk of abnormality was not significantly higher as toxic equivalent concentrations increased in eggs. We also found significant 7-ethoxyresorufin O-deethylase and Cytochrome P4501A responses in livers of hatchling turtles from Lake Ontario relative to hatchlings from a clean, inland site whereas we did not find any evidence of porphyria in the hatchlings from either site.     

The fate of isoproturon in a freshwater microcosm with Lemna minor as a model organism

Degradation, bioaccumulation and volatile loss of the 14C-labeled phenylurea herbicide isoproturon (IPU) was examined in a freshwater microcosm with the free floating macrophyte species Lemna minor during a 21-day exposure time. Isoproturon volatilisation was very low with 0.13+/-0.01% of the initially applied herbicide. Only a minor amount of the herbicide was completely metabolised, presumably by rhizosphere microorganisms and released as 14CO2. In total, about 9% isoproturon was removed from the aquatic medium during 21 days. The major portion of the pesticide was removed by bioaccumulation of Lemna minor (5.0+/-0.8%) and the bioconcentration factor (BCF) based on freshweight was 15.8+/-0.2. However, this study indicated a high persistence of IPU in freshwater ecosystems and a potential hazard due to bioaccumulation in non-target species. The novel experimental system of this study, developed for easy use and multiple sampling abilities, enabled quantitatively studying the fate of isoproturon and showed high reproducibility with a mean average (14)C-recovery rate of 97.1+/-0.7%.     

Changes in the carbon and nitrogen status of forest soil organic horizons between 1949/50 and 1987

Forest soil organic horizons from 15 profiles in NE Scotland originally sampled in 1949/50, were resampled in 1987. Analyses of both sets of soils for organic C and N show that although concentrations of the two elements have decreased with time, there has been a large increase in storage due to an increase in O horizon thickness. In most cases surface organic horizons have become more acid between 1949/50 and 1987. Calculated mean accumulation rates for C and N are 353.4 kg ha(-1) year(-1) and 21.2 kg ha(-1) year(-1) respectively. Changes in the C/N ratio with time give no indication of progressive N saturation and suggest sudden breakthrough of N in drainage water is not imminent.     

Characterization of contaminants in snapping turtles (Chelydra serpentina) from Canadian Lake Erie Areas of Concern: St. Clair River, Detroit River, and Wheatley Harbour

PCBs, organochlorine pesticides and dioxins/furans in snapping turtle eggs and plasma (Chelydra serpentina) were evaluated at three Areas of Concern (AOCs) on Lake Erie and its connecting channels (St. Clair River, Detroit River, and Wheatley Harbour), as well as two inland reference sites (Algonquin Provincial Park and Tiny Marsh) in 2001-2002. Eggs from the Detroit River and Wheatley Harbour AOCs had the highest levels of p,p'-DDE (24.4 and 57.9 ng/g) and sum PCBs (928.6 and 491.0 ng/g) wet weight, respectively. Contaminant levels in eggs from St. Clair River AOC were generally higher than those from Algonquin Park, but similar to those from Tiny Marsh. Dioxins appeared highest from the Detroit River. The PCB congener pattern in eggs suggested that turtles from the Detroit River and Wheatley Harbour AOCs were exposed to Aroclor 1260. TEQs of sum PCBs in eggs from all AOCs and p,p'-DDE levels in eggs from the Wheatley Harbour and the Detroit River AOCs exceeded the Canadian Environmental Quality Guidelines. Furthermore, sum PCBs in eggs from Detroit River and Wheatley Harbour exceeded partial restriction guidelines for consumption. Although estimated PCB body burdens in muscle tissue of females were well below consumption guidelines, estimated residues in liver and adipose were above guidelines for most sites.     

Trace element (Cd, Cu, Hg, Se, Zn) accumulation and tissue distribution in loggerhead turtles (Caretta caretta) from the Western Mediterranean Sea (southern Italy)

Cadmium (Cd), copper (Cu), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the liver, kidney and muscle of 29 loggerhead turtles, Caretta caretta, from the South Tyrrhenian Sea (Western Mediterranean). No significant differences (p>0.05) were detected between males and females. Trace element concentrations were not influenced by the size of the specimen except Se in the liver, which was negatively correlated with the curved carapace length (p<0.001). Muscles generally displayed the lowest trace element burdens, with the exception of Zn which contained concentrations as high as 176 microgg-1dwt. Kidneys displayed the highest Cd and Se mean concentrations (57.2+/-34.6 and 15.5+/-9.1 microgg-1dwt, respectively), while liver exhibited the highest Cu and Hg levels (37.3+/-8.7 and 1.1+/-1.7 microgg-1dwt, respectively). Whichever tissue is considered, the toxic elements had elevated coefficients of variation (i.e. from 60% to 177%) compared to those of the essential ones (i.e. from 14% to 65%), which is a consequence of homeostatic processes for Cu, Se and Zn. Globally, the concentrations of Hg remained low in all the considered tissues, possibly the result of low trophic level in sea turtles. In contrast, the diet of loggerhead turtles would result in a significant exposure to Cd. Highly significant correlations between Cd and Cu and Zn in the liver and kidney suggest that efficient detoxification processes involving MT occur which prevent Cd toxicity in loggerhead turtles.     

Oxidative DNA damage estimated by urinary 8-hydroxydeoxyguanosine: influence of taxi driving,smoking and areca chewing

Nitrogen oxides (NOx) and polycyclic aromatic hydrocarbons are common air pollutants generated from automobile exhaust and cigarette smoke. This study was to investigate urinary 8-hydroxydeoxyguanosine (8-OHdG) as an effective biomarker on DNA damage from traffic exhaust and/or smoking in exposed and non-exposed individuals. With subject consents, the levels of plasma NOx, urinary 1-hydroxypyrene (1-OHP) and 8-OHdG were determined for 95 male taxi drivers and 75 male community residents as the reference group. After adjusting for associate variables, there was a significant correlation between the levels of urinary 8-OHdG and 1-OHP but not NOx. The average level of urinary 8-OHdG was significantly higher in drivers than in community men (13.4+/-4.7 vs. 11.5+/-4.7 microg/g creatinine in mean+/-standard deviation). Compared with non-smoking community men, the multivariate logistic regression showed that the odds ratios (OR) of having elevated levels of urinary 8-OHdG (greater than the overall median value, 12.1 microg/g creatinine) were 6.6 (95% confidence interval (CI)=2.1-20.8) for smoking community men, 5.0 (95% CI=1.7-14.7) for non-smoking taxi drivers and 4.6 (95% CI=1.4-15.0) for smoking taxi drivers. Higher risk was also observed for areca quid chewers compared with non-chewers (OR=1.6; 95% CI=1.1-3.6). In conclusion, taxi driving and smoking may contribute independently to elevated DNA damage using urinary 8-OHdG levels as a sensitive biomarker. This effect is most potent on heavy smokers.     

Toxicity of trichlorotoluene isomers: a 28-day feeding study in the rat

Groups of 10 male and 10 female rats were fed alpha,alpha,alpha-, alpha,2,6- or 2,3,6- trichlorotoluene (TCT) in their diet at 0, 0.5, 5.0, 50 or 500 ppm for 28 days. Growth rate and food consumption were not affected by treatment. No deaths occurred. Significant increases in liver weights were observed in male rats fed 5.0 and 500 ppm 2,3,6-TCT. Mild serum biochemical changes occurred in male rats. These included increased SDH activities in the groups fed 5.0 and 50 ppm alpha, alpha, alpha-TCT, and 5.0 ppm 2,3,6-TCT. Alpha, alpha, alpha-TCT at 500 ppm caused elevated LDH activities in male rats. Hepatic microsomal aminopyrine N-demethylase activities were increased in male rats fed 500 ppm alpha,2,6-TCT. Hematological parameters were not affected by treatment. Mild histological changes were seen in the liver, kidney and thyroid of treated rats. Data presented here suggest that alpha, alpha, alpha-, alpha,2,6- and 2,3,6-TCT possess a low order of oral toxicity in the rat.     

The effects of ozone-exposed sugar maple seedlings on the biological performance and the feeding preference of the forest tent caterpillar (Malacosoma disstria Hbn.)

The effects of exposure of sugar maple (Acer saccharum Marsh.) to ozone on the entire larval stage of a native insect have not been previously investigated. This study reports the effects of sugar maple seedlings exposed to different ozone concentrations on the relative performance and the feeding preference of the forest tent caterpillar (Malacosoma disstria Hbn.). Three-year-old seedlings were set in nine open-top field chambers in the spring of 1992 and 1993. Three ozone concentrations were generated: charcoal-filtered ambient air (0x), ambient air (1x) and three times ambient air (3x). In 1992, female and male larval development time did not differ among ozone treatments. In 1993, female larvae reared on 3x developed faster than those on 0x and 1x, while male larvae were not affected. Ozone treatments did not influence pupal weights except for males in 1993 where pupae reared on 0x were heavier than 1x but did not differ from 3x. Larval and pupal survival rates were not affected by ozone in either year. Finally, 4th and 5th instar larvae showed a significant feeding preference for 3x foliage in 1993 but not in 1992. The response of the forest tent caterpillar to ozone exposed seedlings varied between years and could be more sensitive to annual climatic variations than ozone.     

Effects of spent lubricating oil on the growth of Capsicum annum L. and Lycopersicon esculentum Miller

Susceptibility of the hot pepper (Capsicum annum L.) and the tomato (Lycopersicon esculentum Miller) to spent lubricating oil was investigated in soils supplemented with concentrations of oil ranging from 1-5% w/w. Treatment of soil with 4 and 5% spent oil consistently inhibited germination of both crops. Eighty-four days after sowing, the mean height and leaf area of C. annum in soil treated with 3% spent oil gave the lowest values. These were 3.14 +/- 0.6 cm and 0.24 +/- 0.01 cm(2) compared with respective values of 19.2 +/- 0.2 cm and 2.9 +/- 0.3 cm(2) for control plants. Premature death was observed in the case of L. esculentum plants treated with all tested strengths of spent lubricating oil.     

Effects of cold-dark storage on growth of Cylindrotheca closterium and its sensitivity to copper

Cylindrotheca closterium cells were maintained at low temperature (4+/-1 degrees C) and dark conditions up to 21 weeks to assess the effect on survival and physiological status. From a control culture under standard conditions, three densities were prepared: (A) 2 x 10(4), (B) 10 x 10(4), and (C) 25 x 10(4) cells ml(-1). Weekly, inoculums of each stored density were exposed to continuous light and at 20+/-1 degrees C. Sensitivity to copper for microalgal cultures was evaluated in order to assess possible changes in cells sensitivity due to storage. Concurrently, assays with a control culture were carried out in order to assess the sensitivity of C. closterium to copper and to be able to generate a standard sensitivity control chart with a mean value of EC50-72 h+/-2SD (standard deviation). Density-C presented higher cell yield values, between 40% and 80% relative to control culture. Cell density showed to be important feature that may be taken into account in cell storage experiments. There was an increase in sensitivity of cells submitted to storage; however results always kept in the range established as standard sensitivity with no statistically significant difference with regards to control culture. EC50-72 h mean value for the control culture was 29+/-10 mug Cul(-1), while for densities-A, B and C were 22+/-7; 23+/-9 and 23+/-8 microg Cul(-1), respectively. In spite of drastic changes in the environmental conditions due to storage, it is concluded that C. closterium cells stored during 5 months remained metabolically active and with no significant change in its sensitivity.     

Comparative study on the susceptibility of freshwater species to copper-based pesticides

Copper compounds have been intentionally introduced into water bodies as aquatic plant herbicides, algicides and molluscicides. Copper-based fertilizers and fungicides have been widely used in agriculture as well. Despite the fact that copper is an essential element for all biota, elevated concentrations of this metal have been shown to affect a variety of aquatic organisms. Nonetheless, comparative studies on the susceptibility of different freshwater species to copper compounds have seldom been performed. This study was conducted to compare toxicity of copper-based pesticides (copper oxychloride, cuprous oxide and copper sulfate) to different freshwater target (Raphidocelis subcapitata, a planktonic alga and Biomphalaria glabrata, a snail) and non-target (Daphnia similis, a planktonic crustacean and Danio rerio, a fish) organisms. Test water parameters were as follows: pH = 7.4 +/- 0.1; hardness 44 +/- 1 mg/l as CaCO3; DO 8-9 mg/l at the beginning and > 4 mg/l at the end; temperature, fish and snails 25 +/- 1 degrees C, Daphnia 20 +/- 2 degrees C, algae 24 +/- 1 degrees C. D. similis (immobilization), 48-h EC50s (95% CLs) ranging from 0.013 (0.011-0.016) to 0.043 (0.033-0.057) mg Cu/l, and R. subcapitata (growth inhibition), 96-h IC50s from 0.071 (0.045-0.099) to 0.137 (0.090-0.174) mg Cu/l, were the most susceptible species. B. glabrata (lethality), 48-h LC50s from 0.179 (0.102-0.270) to 0.854 (0.553-1.457) mg Cu/l, and D. rerio (lethality), 48-h LC50s 0.063 (0.045-0.089), 0.192 (0.133-0.272) and 0.714 (0.494-1.016) mg Cu/l, were less susceptible than Daphnia to copper-based pesticides. Findings from the present study therefore suggest that increased levels of copper in water bodies is likely to adversely affect a variety of aquatic species.     

Effects of chlornitrofen, a herbicide, on reproduction of Brachionus urceolaris (Rotatoria) through water and food (Chlorella)

Chronic effects of chlornitrofen (CNP) on the reproduction of Brachionus urceolaris (Rotatoria) were investigated by exposure of individuals to CNP from the egg stage, which had been attached to the adult. The survivors of 12 neonates, which had been exposed to CNP100, 70 or 40 microg liter(-1) decreased to 50% at the age of c. 2, 4 and 6 days, respectively, compared to c. 6.5 days for those exposed to 0, 10 and 20 microg liter(-1) CNP. Release of offspring (mostly two individuals per day) started at two days old. At the peak, four days old, a control female produced 8.1+/-0.9 offspring per day compared with 4.5+/-1.3 (mean+/-SD, n=12) at 40 microg liter(-1). The cumulative numbers of offspring produced by a female were 25.8+/-1.2, 24.2+/-2.9, 22.3+/-3.6 and 13.6+/-3.1 (mean+/-SD, n=12) at control, 10, 20 and 40 microg liter(-1) CNP exposure, respectively. The 50% reproductive impairment concentration was calculated to be 37 microg liter(-1). Growth of neonates was barely detectable at 70 microg liter(-1), and the rapid increase in the effect of CNP from 40 to 70 microg liter(-1) was attributed to an increase in tolerance with growth of the neonates. The effects of CNP on reproduction were also tested by CNP exposure through food (CNP-accumulated Chlorella). The 50% reproductive impairment concentration of CNP in the alga was calculated to be c.60 microg g(-1) (wet weight) by the same method used to assess the dissolved CNP, although the effect of CNP which may have been released from the alga to the water could not be estimated precisely.     

Genotypic variation of nitrogen use efficiency in Indian mustard

This experiment was conducted to investigate the variation of nitrogen efficiency (NE), nitrogen uptake efficiency (UE), physiological nitrogen use efficiency (PUE) among Indian mustard genotypes, grown under N-insufficient and N-sufficient conditions. Nitrogen efficiency varied from 52.7 to 92.8. Seed yield varied from 1.14 t ha(-1) to 3.21 t ha(-1) under N-insufficient condition, while 2.14 t ha(-1)-3.33 t ha(-1) under N-sufficient condition. Physiological basis of this difference was explained in terms of nitrogen uptake efficiency and physiological nitrogen use efficiency, and their relationship with the growth and yield characteristics. While nitrogen uptake efficiency was positively correlated with plant biomass (0.793**), leaf area index (0.664*), and leaf nitrogen content (0.783**), physiological nitrogen use efficiency is positively correlated with photosynthetic rate (0.689**) and yield (0.814**). This study suggests that genotype having high nitrogen uptake efficiency and high physiological nitrogen use efficiency might help in reducing the nitrogen load on soil without any penalty on the yield.     

Toxicity of the herbicide glyphosate to Chordodes nobilii (Gordiida, Nematomorpha)

Nematomorpha (horsehair worms) is a poorly known group of worm-like animals similar to nematodes. Adults are free-living and reproduction takes place in freshwater environments, where preparasitic larvae undergo development. All species have a parasitic juvenil stage and infection may result in the host's death, insects being the most frequent host. Most of the life cycle occurs in freshwater environments, which are often contaminated by different pollutants. Based on the lack of information on the toxicity of herbicides to horsehair worms, the objective of this study is to evaluate the effect of different concentrations of glyphosate (technical grade and formulated product) on Chordodes nobilii (Gordiida, Nematomorpha). Bioassays were performed with embryos and larvae (preparasitic stages), and adults (postparasitic stage). Test organisms were exposed for a short period of time to concentrations ranging between 0.1 and 8 mga.e.l(-1) of glyphosate (technical and formulated). Although embryo development was not inhibited, there was a significant decrease in the infective capacity of larvae derived from eggs that had been exposed to >or= 0.1mg/l. Similar results were obtained for directly exposed larvae. No differences in toxicity were detected between the active ingredient and formulated product. Adult exposed for 96 h to 1.76 mgl(-1) formulated Gly shown a mortality of 50%. Results indicate that C. nobilii is affected at glyphosate concentrations lower than those expected to be found in freshwater environments and those specified in the legislation.     

Soil carbon dynamics and potential carbon sequestration by rangelands

The USA has about 336 Mha of grazing lands of which rangelands account for 48%. Changes in rangeland soil C can occur in response to a wide range of management and environmental factors. Grazing, fire, and fertilization have been shown to affect soil C storage in rangelands, as has converting marginal croplands into grasslands. Carbon losses due to soil erosion can influence soil C storage on rangelands both by reducing soil productivity in source areas and potentially increasing it in depositional areas, and by redistributing the C to areas where soil organic matter mineralization rates are different. Proper grazing management has been estimated to increase soil C storage on US rangelands from 0.1 to 0.3 Mg C ha(-1)year(-1) and new grasslands have been shown to store as much as 0.6 Mg C ha(-1)year(-1). Grazing lands are estimated to contain 10-30% of the world's soil organic carbon. Given the size of the C pool in grazing lands we need to better understand the current and potential effects of management on soil C storage.     

Toxicity and tissue distribution of pentachlorophenol and permethrin in pipistrelle bats experimentally exposed to treated timber

The dependence of bats in Britain on houses as roosts may result in them being exposed to pesticides used in remedial timber treatments. Pentachlorophenol (PCP) and permethrin are used as a fungicide and an insecticide for timber treatment, respectively. The present study investigated toxicity and distribution in body tissues of these two pesticides in pipistrelle bats. Four groups of nine to ten bats were kept in separate outdoor flight enclosures and were provided with roost boxes treated with either PCP only, permethrin, PCP/permethrin mixture or solvent only (control). At the start of the experiment, mean (+/-SE) PCP and permethrin concentrations on the surface of wooden blocks that had been treated in the same way as roost boxes were 69.32+/-6.76 mg g(-1) (n=6) and 3.3+/-1.6 mg g(-1) (n=3), respectively. All bats exposed to PCP and PCP/permethrin treated boxes died within 24 and 120 h, respectively; nine out of the ten controls survived the 32 day experimental period (P<0.001; both groups compared with control). Bats exposed to permethrin treated boxes survived as well as controls. Mean (+/-SE) carcass PCP concentration (excluding deposits on fur) of bats exposed to PCP and PCP/permethrin treated boxes was 13.11+/-2.52 microg g(-1)BW (n=20). PCP burdens on fur were positively correlated with total weight of PCP in the carcass (P<0.001). PCP was present in fat depots, liver, kidney and the remainder of the body which, despite containing low PCP concentrations, was the main PCP reservoir (66.4+/-5.0% of carcass PCP load; n=20). Total PCP in the carcass was significantly correlated with lipid weight (P<0.005). Permethrin was not detectable in body washes and tissues of bats exposed to PCP/permethrin mixture or permethrin.     

Variation in the response of the invasive species Potamopyrgus antipodarum (Smith) to natural (cyanobacterial toxin) and anthropogenic (herbicide atrazine) stressors

In the context of increasing freshwater pollution, the impact on life-traits (survival, growth and fecundity) and locomotion of Potamopyrgus antipodarum of a 5-week field-concentration exposure to the cyanobacterial toxin microcystin-LR and the triazine herbicide, atrazine was studied. Whatever the age of exposed snails (juveniles, subadults, adults), microcystin-LR induced a decrease in survival, growth and fecundity but had no effect on locomotion. Atrazine induced a decrease in locomotory activity but had no significant effect on the life-traits. These results are discussed in terms of consequences to field populations.