Acute toxicity of triphenyltin hydroxide to three cladoceran species

The toxicity of an organotin pesticide, triphenyltin hydroxide, was assessed with several freshwater cladoceran species. Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia were exposed for 48 h to triphenyltin hydroxide in static acute toxicity tests. Values of the 48-h trimmed Spearman-Karber EC(50)s for the three species were found to be 14.5, 16.5, and 11.3 microg litre(-1), respectively. Analysis of variance performed on EC(50) values of replicates revealed no significant differences between the three species. Methods were employed which decrease animal handling stress and increase the accuracy and precision of the concentrations.     

Growth responses of birch and Sitka spruce exposed to acidified rain

Seedlings of birch and Sitka spruce were grown on a range of British soils for 2 years and exposed to simulated acid rainfall treatments of pHs 5.6, 4.5, 3.5 and 2.5. Both species developed visible leaf injury patterns when exposed to the pH 2.5 treatment. In Sitka spruce this leaf injury was followed by high needle loss during the first winter and greater mortality. Generally, height growth of Sitka spruce was unaffected by treatments, but acid rainfall at pH 2.5 increased the height of birch. Mean height of both species was strongly affected by soil type. Significant soils x treatment effects on the heights of both species indicated that on some soils plant growth responses to the treatments did not fit the general pattern. Hence, while the results indicate that generally ambient acidities of rainfall in the UK are unlikely to adversely affect the growth of birch or Sitka spruce, plants growing on some soils may be susceptible to injury.     

The effect of copper sulphate on some biochemical parameters of rainbow trout

Copper sulphate has an adverse effect on some biochemical parameters of trout Salmo gairdneri. The main targets of damage are: (a)Tissue necrosis as demonstrated by increased ASAT and ALAT levels in blood plasma. (b)Inhibition of acetylcholinesterase activity. There is also a general stress effect as reflected by an elevated blood glucose level.     

A new concept: the use of neutrally-buoyant microemulsions for DNAPL remediation

Even in the absence of mobilization of dense nonaqueous phase liquid (DNAPL), the microemulsion that forms when the surfactant solubilizes a dense contaminant such as trichloroethylene will be more dense than water and tends to migrate downward. This paper addresses the issue of migration with a new concept: surfactant enhanced aquifer remediation at neutral buoyancy. Laboratory results of surfactant remediation in two-dimensional model aquifers show that downward migration of microemulsion containing solubilized dense contaminants can be reduced to an acceptable level, even in the absence of capillary barriers in the aquifer. One model experiment was designed to exhibit a small degree of vertical migration and full capture of the microemulsion at the extraction well. The second experiment was designed to demonstrate the effect of large buoyancy forces that lead to excessive downward migration of the microemulsion. Density measurements of aqueous solutions containing sodium dihexyl sulfosuccinate surfactant, isopropanol, trichloroethylene, and sodium chloride are presented. A companion paper presents the results of the flow and transport calculations needed for this approach to surfactant flooding.     

Biochemical response of Norway spruce (Picea abies (L.) Karst.) towards 14-month exposure to ozone and acid mist: effects on amino acid, glutathione and polyamine titers

Two clones of Norway spruce were exposed to elevated ozone levels (100 microg m(-3) with episodes of 130-360 microg m(-3)) in combination with acidic mist (pH 3.0) for two vegetation periods. The plants did not exhibit any visible injury, but levels of several amino acids and polyamines were altered in comparison with control plants (50 microg m(-3) ozone, mist of pH 5.6), the changes being pronounced in clone 14. Total free amino acids as well as methionine titers were increased in clone 14. Asparagine was significantly increased in clone 11 and less so in clone 14. Arginine, which comprised more than 50% of the free amino acids in spruce needles, was not changed by the exposure regime applied. Reduced glutathione was significantly increased in all clones/soil/needle age combinations (average increase 50%). Free soluble putrescine was enhanced by 50-200% in clone 14, but remained unchanged in clone 11. Conjugated putrescine was significantly, and conjugated spermidime was slightly, increased in both clones, whereas other polyamines did not responde to the treatment.     

Mercury levels in the plumage of red-billed gulls Larus novaehollandiae scopulinus of known sex and age

Samples of 4-8 small body feathers were taken from 27 chicks and 35 adult red-billed gulls caught at their nests on the Kaikoura Peninsula, New Zealand, in December 1988. The adults had been ringed as chicks and were of known ages from 2 to 15 years old. Analysis of total mercury in the feather samples showed that levels were independent of sex and age in adults. Mean fresh weight concentration in adult body feathers was 2.4 microg g(-1). The lack of age accumulation of mercury in gull feathers contrasts with the well known age related accumulation of mercury in tissues of fish and marine mammals, but agrees with predictions of recent studies on mercury dynamics in birds. Mercury levels in chick feathers were about 80% of levels in adult feathers.     

Effects of ozone, acid mist and soil characteristics on clonal Norway spruce (Picea abies (L.) Karst.)--an introduction to the joint 14 month tree exposure experiment in closed chambers

This paper introduces a series of publications referring to a single 14-month laboratory study testing the hypothesis that the recent decline of Norway spruce (Picea abies (L.) Karst.) at higher elevations of the Bavarian Forest and comparable forests in medium-range mountains and in the calcareous Alps is caused by an interaction of elevated ozone concentrations, acid mist and site-specific soil (nutritional) characteristics. The effect of climatic extremes, a further important factor, was not included as an experimental variable but was considered by testing of the frost resistance of the experimental plants. Results of these individual studies are presented and discussed in the following 14 papers. Plants from six pre-selected clones of 3-year-old Norway spruce (Picea abies (L.) Karst.) were planted in April 1985 in an acidic soil from the Bavarian Forest, or a calcareous soil from the Bavarian Alps. After a transition period, plants were transferred, in July 1986, into four large environmental chambers and exposed for 14 months to an artificial climate and air pollutant regime based on long-term monitoring in the Inner Bavarian Forest. The climatic exposure protocol followed realistic seasonal and diurnal cycles (summer maximum temperature, 26 degrees C; total mean temperature, 9.8 degrees C; winter minimum, -14 degrees C; mean relative humidity, 70%; maximum irradiance, 500 W m(-2); daylength summer maximum, 17 h; winter minimum, 8 h). Plants were fumigated with ozone, generated from pure oxygen (control: annual mean of 50 microg m(-3); pollution treatment: annual mean of 100 microg m(-3) with 68 episodes of 130-360 microg m(-3) lasting 4-24 h), and background concentrations of SO(2) (22 microg m(-3)) and NO(2) (20 microg m(-3)); windspeed was set at a constant 0.6 m s(-1). Plants were additionally exposed to prolonged episodes of misting at pH 5.6 (control) and pH 3.0 (treatment). Simulation of the target climatic and fumigation conditions was highly reliable and reproducible (temperature +/-0.5 degrees C; rh+/-10%; ozone+/-10 microg m(-3);SO(2) and NO(2)+/-15 microg m(-3)).     

Nutrient accumulation in trees and soil following irrigation with municipal effluent in Australia

Irrigation of tree crops is being evaluated as a method of land disposal of municipal effluent in Australia. A study was carried out from 1980-84 in which seven tree species were sprinkler-irrigated with effluent at an annual rate of 1191-1752 mm. Effective weed control and frequent irrigation resulted in good survival of all species (range 83-100%) at 12 months. Total productivity was estimated at age 4 years by measuring biomass of each species inclusive of litter and roots to a soil depth of 80 cm. Biomass production of the high-yielding species, flooded gum (Eucalyptus grandis) and Sydney blue gum (E. saligna), was around 10 kg m(-2). Percentage leaf mass of these species was small (8-9%) compared with 25% and 29% for the relatively slow-growing river she-oak (Casuarina cunninghamiana) and radiata pine (Pinus radiata). Accumulation of nutrients in the total biomass differed significantly between species and ranged from 34-54 g m(-2) for nitrogen, 4.0-10.4 g m(-2) for phosphorus, 2.1-12.2 g m(-2) for sodium, 22-34 g m(-2) for potassium, 12-61 g m(-2) for calcium and 4.7-9.3 g m(-2) for magnesium. River she-oak and river red gum (E. camaldulensis), because of their relatively large crown and litter masses, accumulated more nitrogen, phosphorus, potassium and calcium than flooded gum or Sydney blue gum. Chemical properties of soils (0-150 cm) were measured in 1980 and again in 1984. Irrigation significantly increased pH (by around 1 unit), throughout the profile. Concentrations of total phosphorus, and exchangeable sodium, calcium and magnesium were increased in the upper profile. Overall, soil chemical properties were not adversely affected by effluent irrigation over the 4-year period, though there was a trend towards more sodic conditions in the soil profile. Nutrient accumulation in soil occurred mainly in the 0-35 cm depth, coinciding with the main root zone of the trees. Renovation of the effluent was therefore estimated as the amount of each nutrient accumulated in the biomass (averaged over the seven species) plus soil (0-35 cm), expressed as a percentage of amount applied in irrigation over the 4 years; that is, nitrogen, 29%; phosphorus, 78%; sodium, 15%; potassium, 26%; calcium, 98% and magnesium, 54%.