Avoidance and toxicity responses of fish to intermittent chlorination

The ability of fish to actively avoid concentrations of chlorine in a steep, horizontal, laboratory-controlled gradient was found to be species-specific and dependent upon the acclimation temperature, water quality conditions, and the type of chlorine residual tested. Comparison of behavioral avoidances with the results from bioassays using some form of intermittent chlorination, as reported in the literature, indicated that LC₅₀ concentrations (levels that cause the mortality of half the test individuals in a designated time period) usually exceeded avoidance threshold concentrations.This chlorine avoidance study, which was carried out in a field laboratory that utilized New River water for holding and testing procedures, was located at the Glen Lyn power plant in southwestern Virginia. Two basic types of avoidance trials were employed, TRC (total residual chlorine) and chloramine (CRC) exposures. The TRC trials contained variable amounts of free (FRC) and combined residual chlorine (CRC) depending upon water quality, while in chloramine trials, the TRC exposure was mainly comprised of monochloramine with little or no FRC. The first significant avoidance in TRC trials for several fish species tested, varied from 0.05 mg/1 for coho salmon (Oncorhynchus kisutch) to 0.40 for channel catfish (Ictalurus punctatus). Low levels of hypochlorous acid (HOCl), which are considered to be a potentially toxic constituent of FRC, appeared to consistently influence the avoidance response. Initial avoidance concentrations to HOCl ranged from 0.01–0.02 mg/1 for coho salmon to 0.04–0.12 mg/1 for channel catfish, depending upon acclimation temperatures tested. The pH in river water was more influential than temperature in controlling the amount of HOCl present within the FRC at each TRC exposure. Avoidance responses by fish to CRC concentrations were either equal to or greater than TRC exposures and were dependent upon the ammonia-N content. Chloramine and FRC (specifically the HOCl fraction) have been reported to have different mechanisms of toxicity, which offered possible explanations for the differences observed in avoidance behavior. Chlorine residuals discharged from the Glen Lyn power plant in previous years have exceeded the LC₅₀ values reported for many species, although no major fish kills from chlorine have been documented. Behavioral avoidance responses by fish to potentially lethal chlorinated discharges in aquatic receiving systems may be a major mechanism of these populations in adapting to or interacting within these industrially influenced environments.     

A FIELD EVALUATION OF THE EFFECTS OF HEATED DISCHARGES ON FISH DISTRIBUTION1

ABSTRACT. Studies were conducted to determine the distribution of fish in the New and East Rivers in relation to thermal discharges from Appalachian Power Company's fossil fuel plant at Glen Lyn, Virginia. Over 15,300 specimens representing 41 species were collected with seines, electrogear and rotenone at six sampling locations from February, 1973 to October 1973. Sampling frequency was designed to evaluate the effects of ambient temperature upon preferred temperature. Diversity indices were calculated for each location. There was a slight decrease in the diversity indices for those stations located in the thermal discharge. Condition coefficients calculated for Notropis albeolus Jordan, Notropis rubellus Aqasaiz, Notropis spilopterus Cope, Ictalurus punctatus Rafinesque, and Etheostoma blennioides Rafuesque were found to be significantly (p =.05) lower in the thermal discharge for all species tested except E. blennioides. Temperatures were plotted against frequency of capture to determine a particular species temperature selection from field data and indicated that: (1) Some species avoided high temperatures (i.e., Curnpostoma anomalum Rafuesque). (2) Some species were attracted to high temperatures (i.e., Ictalurus punctatus). (3) Some species distribution was not effected by temperatures (i.e., Notropis spilopterus).     

ENVIRONMENTAL IMPACTS OF APPLYING MANURE,FERTILIZER, AND SEWAGE BIOSOLIDS ON A DAIRY FARM1

ABSTRACT: Farms that once spread only manures are now also applying sewage biosolids (sludge) and/or other wastes such as those from food processing. The objective of this study was to monitor environmental impacts at a dairy farm applying these materials. Fields were selected representing recent waste applications of manure (M1, M2), sewage biosolids (B1, B2), or fertilizer only control (F1, F2), although most fields had historical biosolids applications. Fields representing each treatment were not experimental replicates because of varying applications and soil characteristics. Septage and food processing wastes were also applied. Soil percolates were collected with wick lysimeters. Runoff was sampled at seven stream sites. Test field soils and alfalfa (Medicago sativa) were analyzed for trace elements. Cumulative trace metal loadings were low, at most only 1 percent of USEPA Part 503 limits. Surface soil enrichment was most evident for Mo, P, and S. Alfalfa tissue showed no trends of concern. The B2 site had the greatest percolate concentrations for 6 of 13 elements. Percolate Cu was somewhat elevated at Sites M1, M2, B2, and Fl. Percolate sodium was elevated on all M and B fields and sulfur was greatest at M2, B1, and B2. Soluble orthophosphate correlated with stream discharge during intensive monitoring of Stream Sites S1 (fertilizer) and S2 (biosolids). Peaks in S2 streamwater Mo lagged large runoff events by five days. Total streamwater export of Cu, Na, Mo, and soluble P were greater from the S2 biosolids subwatershed than from the S1 fertilizer subwatershed. Percolate concentrations exceeded corresponding streamwater concentrations in most cases.     

A STATISTICAL APPROACH TO ASSESS FACTORS AFFECTING WATER CHEMISTRY USING MONITORING DATA1

ABSTRACT: A method to partition the variation in concentrations of water chemistry parameters in a river is described. The approach consists of fitting a family of curves for each chemical parameter. Each curve indicates the response of the parameter to river flow for a particular time period or location. An analysis of covariance is then used to identify statistically significant differences between curves. Such differences result largely from two factors: (1) the discharge of effluents and (2) river flow-concentration relationships. The deviations from the fitted curves indicate month-to-month variations unrelated to river flow that are controlled by factors such as temperature-related seasonal patterns. Underlying statistical assumptions are discussed with respect to water chemistry data. The technique is applied to a data set consisting of monthly samples of 22 water chemistry parameters from the Sulphur River of Texas and Arkansas. Several patterns of response to river flow and to two effluent discharges were revealed.     

Comparison of surface emissions and subsurface distribution of cis- and trans-1,3-dichloropropne and chloropicrin in sandy field beds covered with four different plastic films

The purpose of this study was to conduct a field study at a Florida field site on surface emissions and subsurface distribution of cis-and trans-1,3-dichloropropene (1,3-D) and chloropicrin (CP) in raised beds injected with Telone C35 with four replications. A total of 16 beds were applied with Telone C35 by chisel injection and covered with four different plastic films, 4 beds for each film. Each bed was installed with five 20-cm long soil pore air probes and a surface air collection pan at arbitrarily locations along the length of each bed for sampling soil pore air and surface air, respectively, for analysis of the three biologically active compounds, cis- and trans-1,3-D and CP. We found that average concentrations of the three compounds at 20-cm depth among the beds covered with four different plastic films generally were not statistically different. Among the four beds covered with the same plastic film, average concentrations of the three compounds were statistically different only in the four metallic PE covered beds at 5 and 24 hours after injection. Volatilization rates of the three compounds among the beds covered with four different plastic films, with the exception of CP at 48 hours after injection, were not statistically different. It appeared that initial upward diffusion and volatilization flux were influenced by solar radiation. Initial subsurface concentrations of the three compounds and volatilization flux, especially cis-1,3-D, were greater in the beds on the east side of the field than that in the beds on the west side of the field. Whether or not difference in initial subsurface concentrations of the compounds between east side beds and west side beds may influence fumigant efficacy remains to be determined.     

Grassland Plant Composition Alters Vehicular Disturbance Effects in Kansas,USA

Many “natural” areas are exposed to military or recreational off-road vehicles. The interactive effects of different types of vehicular disturbance on vegetation have rarely been examined, and it has been proposed that some vegetation types are less susceptible to vehicular disturbance than others. At Fort Riley, Kansas, we experimentally tested how different plant community types changed after disturbance from an M1A1 Abrams tank driven at different speeds and turning angles during different seasons. The greatest vegetation change was observed because of driving in the spring in wet soils and the interaction of turning while driving fast (vegetation change was measured with Bray-Curtis dissimilarity). We found that less vegetation change occurred in communities with high amounts of native prairie vegetation than in communities with high amounts of introduced C₃ grasses, which is the first experimental evidence we are aware of that suggests plant communities dominated by introduced C₃ grasses changed more because of vehicular disturbance than communities dominated by native prairie grasses. We also found that vegetation changed linearly with vehicular disturbance intensity, suggesting that at least initially there was no catastrophic shift in vegetation beyond a certain disturbance intensity threshold. Overall, the intensity of vehicular disturbance appeared to play the greatest role in vegetation change, but the plant community type also played a strong role and this should be considered in land use planning. The reasons for greater vegetation change in introduced C₃ grass dominated areas deserve further study.     

Recent advances in aerial gamma-ray surveying

Aerial gamma-ray surveying uses NaI(Tl) detectors mounted in small aircraft to measure gamma radiation, emitted from the earth's surface. The data are collected as gamma-ray spectra, typically with 1 s counting times, from which are derived K, U and Th concentrations in the ground. Applications of aerial surveying include geological mapping for mineral exploration, soil mapping for agriculture, pollution studies and location of lost sources. Recent advances in applying statistical methods to the spectral data have resulted in large reductions in the noise levels in the surveys. Some of the methods available to do this include noise adjusted singular value decomposition (NASVD) [Proceedings of Exploration 97: Fourth Decennial International Conference on Mineral Exploration (1997) 753] and maximum noise fraction (MNF) and enhanced MNF (eMNF) [Explor. Geophys. 31 (2000) 73]. These methods, in general, apply normalization for variance to the spectra, use a principal component method to obtain the "significant" components of the data and reconstruct cleaned spectra, which are then processed in a standard manner to get radionuclide concentrations. However, they differ in the detail of the application and thus give slightly different results. In this paper, the application of noise reduction methods to various synthetic surveys is used to examine the strengths and weaknesses of the methods. In tests where there are high correlations between U and Th, the eMNF method performs best although the results are improved by prior clustering of the data by the Th/U ratio. If the data show no correlations, then the effectiveness of all the noise removal methods is reduced. If a data set is small (<1500 spectra), then MNF appears to be the better method. Consideration of the various tests suggests an optimum process whereby spectra are sorted into groups by the Th/U ratio of areas identified in a standard processing and then cleaned by eMNF or MNF, depending on the number of spectra in each group.     

Assessment of rainwater volatile organic carbon in southeastern North Carolina,USA

Extensive production of ethanol and vehicular use of this biofuel have recently been suggested as possible sources of elevated volatile organic carbon (VOC) in rain in Brazil (Campos, M.L.A.M., Nogueira, R.F.P., Dametto, P.R., Francisco, J.G., Coelho, C.H., 2007. Dissolved organic carbon in rainwater: glassware decontamination and sample preservation and volatile organic carbon. Atmos. Environ. 41, 8924–8931; Coelho, C.H., Francisco, J.G., Nogueira, R.F.P., Campos, M.L.A.M., 2008. Dissolved organic carbon in rainwater from areas heavily impacted by sugar cane burning. Atmos. Environ. 42, 7115–7121). Furthermore, these studies suggested that the global flux of rainwater dissolved organic carbon (DOC) may be underestimated since most DOC analytical methods do not measure VOC. The current study examined rain VOC in Wilmington, North Carolina USA in order to assess the importance of rain VOC in a location that does not have the unique conditions of ethanol production and usage found in Brazil. VOC was observed in one of six whole rain events analyzed in the current study. This event had an air mass back trajectory that originated over the Midwestern USA, the primary region where ethanol is produced and used as fuel. The other five storms which had no influence from the central US prior to arrival at the rain collection site had non-detectable VOC suggesting that air mass back trajectory has a dramatic impact on the VOC content of rainwater. VOC was also observed in the initial 1 mm of rain from two of these events but was not detectable in the whole event samples suggesting VOC is efficiently washed out of the atmosphere and is not rapidly resupplied in rainwater at this location. Considering the results of the previous Brazilian studies and the current study, and the likelihood of increased global production and consumption of ethanol based biofuels, it is imperative that future measurements of rainwater DOC include measurement of VOC. Monitoring changes in the VOC contribution to rain DOC will provide an assessment of the impact of increased ethanol biofuel usage on rainwater composition and allow for future refinements of global rainwater DOC flux estimates.     

Enhanced multi-metal extraction with EDDS of deficient and excess dosages under the influence of dissolved and soil organic matter

This study investigated the influence of dissolved and soil organic matter on metal extraction from an artificially contaminated soil. With high concentration of DOM, the extraction of Cu, Zn and Pb was enhanced by forming additional metal-EDDS complexes under EDDS deficiency. However, the enhancement of metal extraction under EDDS excess was probably due to the soil structure being disrupted owing to humic acid enhanced Al and Fe dissolution, which induced more metals dissolving from the soils. Fulvic acid was found to enhance metal extraction to a greater extent compared with humic acid because of its high content of the carboxylic functional group. Cu extraction from the soil with high organic matter content using EDDS was the lowest due to the high binding affinity of Cu to SOM, whereas Zn extraction became the highest because of a preference for EDDS to extract Zn due to the high stability constant of ZnEDDS.