No description available.

No description available.

No description available.

nÃo hà / A preocupaÃÃo com processos que causam degradaÃÃo da qualidade dos recursos hÃdricos e dos ecossistemas aquÃticos tem se acentuado, principalmente, devido a enorme quantidade de poluentes e novas substÃncias que adentram nesse meio. Objetivou-se, com este trabalho, ampliar o conhecimento sobre a comunidade de macroinvertebrados aquÃticos do reservatÃrio GaviÃo em Itaitinga (CE), onde ocorre a captaÃÃo das Ãguas para o sistema de abastecimento de Ãgua da regiÃo metropolitana de Fortaleza e avaliar como os organismos respondem à disposiÃÃo dos resÃduos da ETA GaviÃo, utilizando o Ãndice BMWPâ. As coletas foram realizadas mensalmente, empregando um coletor do tipo Surber (500 Âm de abertura de malha) no perÃodo de outubro 2012 a maio de 2013. Foi coletado um total de 1.621 espÃcimes, distribuÃdos em 23 taxa. Mollusca foi o grupo dominante e frequente e Insecta apresentou maior riqueza. Segundo o Ãndice BMWPâ, verificou-se que o reservatÃrio GaviÃo encontra-se com suas Ãguas em qualidade duvidosa. / Concerns with the processes that cause water resources and ecosystem degradation are on the rise, especially because of large amounts of pollutants and substances that enter this medium. This study aimed to evaluate water macroinvertebrate communities in tanks used for water collection for urban use and to assess how organisms respond to waste generated in the water treatment plant. We collected a total of 1,621 specimens, distributed into 23 taxa. Mollusca was the dominant and frequent group and insecta was the most abundant. Based on feeding mode, there are more predatory organisms in relation to scrapers. We found no eudominant families. By using the BMWPâ score we verified that water quality in the âGaviÃoâ reservoir is questionable.

No description available.

South Africa produces large amounts of solid mine waste, covering vast areas of land in the form of tailings dam facilities (TDF). Tailings material contains high levels of elements which poses potential risk for the environment and human health due to their potential toxic character. Agricultural practices such as tilling and chemical additions can also cause leaching of potentially harmful toxins into the surrounding environment. Both these soils are disturbed on a physical level, influencing the soil structure, chemical composition and soil biota present. This study analyzed in a comparative manner the chemical and physical properties of soils collected from gold mine tailings, agricultural areas and natural areas, and the consequences for soil life. Soil samples for the different land use types were taken in duplicate from the KwaZulu- Natal and North West provinces in South Africa. Topsoil layer formation was analyzed for all sites by sampling at depths of 0-5cm, 5-15cm and 15-25cm. Soil element content was assessed by means of metal indices. The physical and chemical characteristics of the soil were further analyzed by life cycle parameters of the oligochaete species Eisenia andrei and Enchytraeus doerjesi in gold mine tailings and agricultural soils. Ants were collected from all the land use types for species identification and analysis of element content. Soil layering regarding the vertical distribution of elements was observed in concentrations analyzed for the different land use types. Mining sites, especially in KwaZulu-Natal, indicated a decrease in element concentrations with increased depth. The opposite tendency was observed for the agricultural and natural soils, indicating increased concentrations with increased depth. Analysis of the elements indicated high levels of pollution in the mining sites which according to the metal indices were Co, Cd, and Ni. It was determined that tailings material from KwaZulu- Natal was more polluted than the tailings material from the mine in North West province, according to soil indices. Tailings material from both mining sites resulted in negative impacts on E. andrei and E. doerjesi, based on growth, hatching success, mortality and reproduction rate. A unique approach was taken during this study by exposing cocoons of E. andrei to soil samples. The negative effects of the mining samples on test species could be a result of the low organic matter, poor structure and high element content of the mining waste, compared to the agricultural and natural soil. Species numbers of ants were higher on the tailings material than agricultural and natural soils. Element analysis of ants collected, indicated high accumulation of elements such as Fe, Al, Cr, Cd, Pb, Cu and Zn in total body element content of one or more species, reflecting the combination of elements found in the different land use types. Accumulation levels were highest in Pheidole sp. compared to other species investigated. Ants are potential indicators of soil pollutants within a South African context. Risk assessment is necessary for analyzed soils to determine steps for sustainable re-use. A key system with regards to soil pollutant analyses should be incorporated in government policy for protection of South African soil. / PhD (Environmental Sciences), North-West University, Potchefstroom Campus, 2014

South Africa produces large amounts of solid mine waste, covering vast areas of land in the form of tailings dam facilities (TDF). Tailings material contains high levels of elements which poses potential risk for the environment and human health due to their potential toxic character. Agricultural practices such as tilling and chemical additions can also cause leaching of potentially harmful toxins into the surrounding environment. Both these soils are disturbed on a physical level, influencing the soil structure, chemical composition and soil biota present. This study analyzed in a comparative manner the chemical and physical properties of soils collected from gold mine tailings, agricultural areas and natural areas, and the consequences for soil life. Soil samples for the different land use types were taken in duplicate from the KwaZulu- Natal and North West provinces in South Africa. Topsoil layer formation was analyzed for all sites by sampling at depths of 0-5cm, 5-15cm and 15-25cm. Soil element content was assessed by means of metal indices. The physical and chemical characteristics of the soil were further analyzed by life cycle parameters of the oligochaete species Eisenia andrei and Enchytraeus doerjesi in gold mine tailings and agricultural soils. Ants were collected from all the land use types for species identification and analysis of element content. Soil layering regarding the vertical distribution of elements was observed in concentrations analyzed for the different land use types. Mining sites, especially in KwaZulu-Natal, indicated a decrease in element concentrations with increased depth. The opposite tendency was observed for the agricultural and natural soils, indicating increased concentrations with increased depth. Analysis of the elements indicated high levels of pollution in the mining sites which according to the metal indices were Co, Cd, and Ni. It was determined that tailings material from KwaZulu- Natal was more polluted than the tailings material from the mine in North West province, according to soil indices. Tailings material from both mining sites resulted in negative impacts on E. andrei and E. doerjesi, based on growth, hatching success, mortality and reproduction rate. A unique approach was taken during this study by exposing cocoons of E. andrei to soil samples. The negative effects of the mining samples on test species could be a result of the low organic matter, poor structure and high element content of the mining waste, compared to the agricultural and natural soil. Species numbers of ants were higher on the tailings material than agricultural and natural soils. Element analysis of ants collected, indicated high accumulation of elements such as Fe, Al, Cr, Cd, Pb, Cu and Zn in total body element content of one or more species, reflecting the combination of elements found in the different land use types. Accumulation levels were highest in Pheidole sp. compared to other species investigated. Ants are potential indicators of soil pollutants within a South African context. Risk assessment is necessary for analyzed soils to determine steps for sustainable re-use. A key system with regards to soil pollutant analyses should be incorporated in government policy for protection of South African soil. / PhD (Environmental Sciences), North-West University, Potchefstroom Campus, 2014

Most environmental studies concerning the environmental health of the Swan- Canning River system have focussed on nutrient inputs from both rural and urban catchments that are the cause of algal blooms. On occasions these algal blooms have resulted in fish deaths attributed to oxygen starvation. Relatively few studies have examined whether non-nutrient contamination is affecting the health of the riverine environment. Those studies that have, have concentrated on measuring the levels of heavy metals, organochlorines, organophosphates, and hydrocarbons in the sediments and water of the river system, and in the flesh of the biota. However, chemical analysis often fails to detect chemicals of concern due to high laboratory detection limits. In addition, analysis of the body burden of contaminants within biota does not necessarily convey if exposure is inducing adverse effects at the individual or ecosystem levels. The use of biochemical markers as a tool for the assessment of the health of the Swan-Canning River system was examined under a collaborative research project with the Waters and Rivers Commission, established in response to the recognition of the paucity of information from chemical analyses. The present study focussed on the estuarine portion of the Swan-Canning River system, using the black bream (Acanthopagrus butcheri), an estuarine dependent fish species, as a biomonitoring tool. Prior to the commencement of this study it had been determined that the black bream was a suitable fish species for use as a biomonitoring tool when using mixed function oxygenase (MFO) activity induction under laboratory conditions. / Biopsies taken from feral black bream collected from eight sites during the period 2000 to 2002 from the estuary confirmed that the use of MFO induction in this fish species as a biomarker of exposure to organic contaminants is a reliable biomarker. Fish gender was a confounding factor in the interpretation of MFO induction when using the enzyme ethoxyresorufin-O-deethylase (EROD) as EROD activity was suppressed in both pre- and post-spawning female black bream. No such suppression was identified when using the MFO enzyme ethoxycoumarin-O-deethylase (ECOD). However, due to differences in the pattern and intensity of the induction of EROD and ECOD activities it was concluded that ECOD activity was not a substitute for EROD activity to detect certain chemical as ECOD activity represents a different cytochrome P450 pattern to EROD activity. No spatial, seasonal or interannual differences in the level of the enzyme sorbitol dehydrogenase (SDH) in the blood of the black bream were measured indicating that the interpretation of MFO activity induction was not compromised by hepatocellular damage. This study has shown that the black bream in the Swan-Canning Estuary are exposed to, and are metabolising polycyclic aromatic hydrocarbons (PAHs), notwithstanding that the chemical analysis of the contaminant load of these substances in the estuarine waters is consistently below laboratory detection limits. In addition, biomarker responses such as ECOD activity indicate that various other organic pollutants are present and are being metabolised by the black bream. / The measurement of biliary metabolites clearly show that, under winter conditions, the comprehensive drainage system of the Swan Coastal Plain contributes PAHs from pyrogenic sources such as burnt fuels into the estuary although the onset and intensity of rainfall events notably impacts on the volume of stormwater inflow. During the summer months, when freshwater flow is minimal, petrogenic sources of PAHs are dominant. Metabolic enzyme analysis points to the black bream being challenged in their aerobic capacities during summer, and that gill tissue was the most suitable tissue to evaluate the aerobic and anaerobic capacity of this fish species. Furthermore, there was a significant negative correlation between stress protein (hsp70) expression and DNA integrity in field-collected fish suggesting that the black bream within the estuary are highly stressed. No gradient of response in biomarker levels was identified in the Swan-Canning Estuary under either winter or summer conditions indicating there are multiple sources of inputs of potential pollutants along the length of the estuary. Stormwater and road runoff are the primary source of pollutant input into the estuary in the winter months, while summer biomarker levels, particularly PAH, appear to reflect the high usage of the estuary for recreational purposes and runoff from poorly irrigated parks and gardens. Significant rainfall events at any time of the year have the potential to adversely impact the biota of the estuary, particularly when these events result in a flush of water from the drains following long dry periods. / The study shows that the black bream is a suitable fish species to use under field conditions to detect the presence of bioavailable non-nutrient contamination within the Swan-Canning Estuary. A suite of biomarkers in black bream have been tested seasonally and annually but only a small number of biomarkers have proven suitable for routine monitoring of the health of the Swan-Canning Estuary. This treatise concludes with several recommendations for further investigations into biomarkers of fish health for the purpose of increasing our understanding on the sources and type of contamination entering the estuary, and potential effects on the aquatic biota of the Swan-Canning River system. These recommendations include, but are not limited to: (1) the need to determine baseline levels for the different biomarkers investigated in this study, (2) the examination of the Moore River or the Warren River estuaries as potential reference sites for biomarker studies in the Swan- Canning Estuary, (3) the advantage of identifying a second estuarine-dependent indigenous fish as a biomonitoring tool, (4) the requirement for a targeted study aimed at clarifying the relationship between major drain discharges, biomarker levels and impacts on river biota, and (5) a study of estuarine waters utilising SPMDs be undertaken in tandem with biomarker analysis of field captured fish would be beneficial.

Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.

Currently there are three companies producing bitumen from the Athabasca Oil Sands Region located near Fort McMurray, Alberta, Canada. Extraction of bitumen produces solid (sand) and liquid (water with suspended fine particles) tailings material, called oil sands process affected-materials (OSPM). These waste materials are stored on site due to a zero discharge policy and must be reclaimed when operations end. The OSPM is known to contain naphthenic acids (NAs) and polycyclic aromatic hydrocarbons (PAHs) and has high pH and salinity. A possible method of reclamation is the wet landscape approach, which involves using OSPM to form wetlands that would mimic natural wetland ecological functioning. This study investigated the effects of wetlands formed with OSPM on wood frog larvae (<i>Rana sylvatica</i>), using endpoints including survival, growth, time to metamorphosis, hormonal status, and detoxification enzyme induction [ethoxyresorufin-o-dealkylase (EROD) activity].<p> <i>In-situ</i> caging studies were completed in 2006 and 2007. Four wetlands were studied in 2006 and 14 wetlands were studied in 2007. The 2006 season saw a host of problems that were resolved for the 2007 season. In 2006, tadpole survival did not differ among reference wetlands and old OSPM-affected wetlands but there was 100% mortality of tadpoles in the young OSPM-affected sites that contain the highest concentration of toxic components. Results were similar in 2007, with tadpoles raised in young OSPM-affected wetlands having 41.5%, 62.6%, and 54.7% higher tadpole mortality than old OSPM-affected, young reference, and old reference wetlands, respectively. In 2007, tadpoles from young OSPM-affected sites had delayed metamorphosis (12 days longer than tadpoles from old reference wetlands and 18 days longer than tadpoles in old OSPM-affected wetlands). The thyroid hormone ratios of tadpoles in young OSPM-affected wetlands were between 25% and 42% lower than tadpoles in all other wetlands groups. The EROD activity of tadpoles in young OSPM-affected wetlands was an average 223% higher than those in old OSPM-affected wetlands, showing us that tadpoles were responding to higher levels of contaminants in young OSPM-affected wetlands. Size differences were only noted in 2007, most likely not as a result of exposure to OSPM, but due to differences in population density. The results of this study lead us to believe that toxicity due to OSPM decreases as wetlands get older and OSPM-affected wetlands could support native amphibian populations if they are allowed to mature. Since we considered wetlands to be old if they were seven years or older and the fact that old-OSPM wetlands showed effects on tadpoles similar to those of reference wetlands and showed much less toxicity than young OSPM-affected wetlands, we believe wetlands that are at least seven years old would sustain amphibian life.