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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Spatial and temporal changes of macroinvertebrate community structure in two UK lowland river systems

Cao, Yong January 1995 (has links)
No description available.
2

Determining attainable ecological quality requirements for the Upper Wonderfonteinspruit Catchment, based on human community requirements : the case of Bekkersdal / Simone Laila Liefferink

Liefferink, Simone Laila January 2015 (has links)
In order for an economy to survive and thrive it requires resources. Water is a resource that not only the economy is dependent on but also ecological and human communities. The deteriorated state of South African rivers suggests the intensive use of the country’s freshwater reserves by the population and industry. Such a source of freshwater is the Wonderfonteinspruit. It flows through an area that requires water for gold mining that has taken place in the area for more than 120 years. Furthermore, the Wonderfonteinspruit runs past communities such as Bekkersdal and eventually forms part of the source waters for the Boskop Dam, the main drinking water reservoir for Potchefstroom. Literature suggests that the Wonderfonteinspruit is impacted by anthropogenic activities, in particular impacts associated with both historical and current gold mining activities. The Wonderfonteinspruit has its origin in the Tudor Dam in Krugersdorp (now Mogale City), and then flows into Donaldson Dam from where it is piped in a 32 km long pipeline, before its confluence with the Mooi River which subsequently flows into the Boskop Dam. The study area specifically focuses on the Upper Wonderfonteinspruit from just downstream of the Donaldson Dam to just upstream of the dam. The study area was selected due to the close proximity of the Donaldson Dam to the community of Bekkersdal which formed the second part of the investigation for this thesis. Bekkersdal is primarily a mining community that has historically faced issues with sufficient land provision, housing, unemployment and service delivery. It is located in the Gauteng Province and falls under the jurisdiction of Westonaria Local Municipality. Recent protests by community members have occurred due to the lack of service delivery and inappropriate development of infrastructure with regards to water services. Due to the close proximity of Bekkersdal to the Wonderfonteinspruit (as it is situated on the border of the Donaldson Dam) the community provided an ideal study area to explore the use of the river by the community. In order to determine the relationship between the Wonderfonteinspruit and the community of Bekkersdal the study comprised two parts: during the first part of the study, the ecological state of the Wonderfonteinspruit was determined through the evaluation of the quality of water, sediment and biota within the river; while in the second part an assessment of Bekkersdal (both formal and informal sections) was undertaken through the use of questionnaires in order to determine past, current and future water use of both municipal water and water sourced from the Wonderfonteinspruit. The final outcomes of both the environmental and social assessments were then compared with national and international standards. Water quality assessment of the Wonderfonteinspruit was done by assessing the following: - in situ water quality parameters (such as pH, total dissolved solids and dissolved oxygen) - metal and ionic composition analysis of water samples using inductively coupled plasma mass spectrophotometry (ICP-MS) - nutrient loads using a spectrophotometer and Spectroquant® test kits - bacteriological quality by determining presence of total coliforms and faecal coliforms through the growth of bacterial cultures on M-ENDO and m-FC agar plates - the Physico-chemical Driver Assessment Index (PAI) was applied according to DWAF 2008 - statistical relevance between sites and results through principal component analysis (PCA) Finally, these results, where applicable, were compared to both national and international standards for human and ecological use. The results indicated that the water quality levels exceeded the guideline values of national and international standards for the following uses: drinking water, certain industrial activities, watering of certain livestock and crop types as well as aquaculture. It was also found that the water quality was acceptable for certain activities (e.g. recreation) only if precautions and further analysis are performed. The guideline values of national water quality standards for ecological status were also exceeded, while the PAI results indicated that the ecological category (EC) for the Wonderfonteinspruit is a D which indicates that the state of the water quality in terms of the ecology is fair. The sediment quality of the Wonderfonteinspruit was determined by ICP-MS. The metal composition of the sediment was compared to that of other rivers and the following indices were applied: enrichment factor (EF), contamination factor (CF), pollution load index (PLI) and geo-accumulation index (Igeo). It was found that the sediment composition is comparable to that of other rivers impacted by gold mining and that uranium, cobalt and nickel enriched the sediment according to the indices. Biotic indicators that were assessed included fish, diatoms and invertebrates. The fish health assessment index (HAI) was applied to fish caught in the Donaldson Dam. The muscle tissue was also removed and its metal concentration was determined by ICP-MS. Thereafter, the edibility of the fish muscle tissue was determined and the following indices were applied: condition factor (CF), hepatosomatic index (HSI), gonadosomatic index (GSI) and spleen somatic index (SSI). The diatom community composition was assessed by applying the Biological Diatom Index (BDI), Specific Pollution Sensitivity Index (SPI) and the percentage pollution tolerant valves (%PTV). The Macroinvertebrate Response Assessment Index (MIRAI) was applied in order to determine the state of the macroinvertebrate community. The fish assessment indicated that arsenic contamination may negatively impact the health of consumers. Diatom indices indicated that the EC of the Wonderfonteinspruit is a D/E which indicates poor water quality; likewise, this is supported by the MIRAI results as the EC for MIRAI was a D which indicates that the river is largely modified. The investigation into the water use of the Bekkersdal community, with a special focus on the use of the Wonderfonteinspruit, was achieved through the use of questionnaires that were distributed in both formal and informal sections in Bekkersdal. The research forms part of a larger Integrative Multidisciplinary study and was given ethical clearance under the NRF Community Engagement Project (see Ethical Clearance: no. FH-BE-2013-0014. The National Research Fund (NRF) provided the funding for the research, the views expressed is that of the author and not those of the NRF. The aim of the questionnaire was to determine the following aspects in terms of the community of Bekkersdal: - Demographic details, such as language preference, employment status and age distribution. - Current water use practices . - Use of the Wonderfonteinspruit. - Future water use of the Wonderfonteinspruit. - Water quality perceptions of the Wonderfonteinspruit. - Field notes that included any relevant observations of the fieldworkers. The unemployment rate of the Bekkersdal community was found to be high (78.20%) and 86.40% of the residents are South African citizens. The community relies heavily on municipal provision of sources of water with 100% of the respondents indicating that it is their primary source of water. However, several issues were identified in terms of municipal water supply in the community. Some 10.14% of the residents indicated that they make regular use of the Wonderfonteinspruit (in particular the Donaldson Dam) most often for drinking water, laundry and washing of cars, etc. Regarding the state of the Wonderfonteinspruit, the overall viewpoint of the Bekkersdal community was that it is largely polluted with sewage, litter and mining waste. However, some 87.80% of the residents expressed their willingness to participate in environmental clean-up initiatives in their area. The link between the ecological state of the Wonderfonteinspruit and human health and wellbeing was explored through the use of spider diagrams where rank scores were assigned to both index results and human water quality use categories. These were compared and it was found that ecological indicators are more sensitive than human water quality use scores and therefore can aid in acting as early detection indicators of possible negative impacts on human health and wellbeing. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
3

Determining attainable ecological quality requirements for the Upper Wonderfonteinspruit Catchment, based on human community requirements : the case of Bekkersdal / Simone Laila Liefferink

Liefferink, Simone Laila January 2015 (has links)
In order for an economy to survive and thrive it requires resources. Water is a resource that not only the economy is dependent on but also ecological and human communities. The deteriorated state of South African rivers suggests the intensive use of the country’s freshwater reserves by the population and industry. Such a source of freshwater is the Wonderfonteinspruit. It flows through an area that requires water for gold mining that has taken place in the area for more than 120 years. Furthermore, the Wonderfonteinspruit runs past communities such as Bekkersdal and eventually forms part of the source waters for the Boskop Dam, the main drinking water reservoir for Potchefstroom. Literature suggests that the Wonderfonteinspruit is impacted by anthropogenic activities, in particular impacts associated with both historical and current gold mining activities. The Wonderfonteinspruit has its origin in the Tudor Dam in Krugersdorp (now Mogale City), and then flows into Donaldson Dam from where it is piped in a 32 km long pipeline, before its confluence with the Mooi River which subsequently flows into the Boskop Dam. The study area specifically focuses on the Upper Wonderfonteinspruit from just downstream of the Donaldson Dam to just upstream of the dam. The study area was selected due to the close proximity of the Donaldson Dam to the community of Bekkersdal which formed the second part of the investigation for this thesis. Bekkersdal is primarily a mining community that has historically faced issues with sufficient land provision, housing, unemployment and service delivery. It is located in the Gauteng Province and falls under the jurisdiction of Westonaria Local Municipality. Recent protests by community members have occurred due to the lack of service delivery and inappropriate development of infrastructure with regards to water services. Due to the close proximity of Bekkersdal to the Wonderfonteinspruit (as it is situated on the border of the Donaldson Dam) the community provided an ideal study area to explore the use of the river by the community. In order to determine the relationship between the Wonderfonteinspruit and the community of Bekkersdal the study comprised two parts: during the first part of the study, the ecological state of the Wonderfonteinspruit was determined through the evaluation of the quality of water, sediment and biota within the river; while in the second part an assessment of Bekkersdal (both formal and informal sections) was undertaken through the use of questionnaires in order to determine past, current and future water use of both municipal water and water sourced from the Wonderfonteinspruit. The final outcomes of both the environmental and social assessments were then compared with national and international standards. Water quality assessment of the Wonderfonteinspruit was done by assessing the following: - in situ water quality parameters (such as pH, total dissolved solids and dissolved oxygen) - metal and ionic composition analysis of water samples using inductively coupled plasma mass spectrophotometry (ICP-MS) - nutrient loads using a spectrophotometer and Spectroquant® test kits - bacteriological quality by determining presence of total coliforms and faecal coliforms through the growth of bacterial cultures on M-ENDO and m-FC agar plates - the Physico-chemical Driver Assessment Index (PAI) was applied according to DWAF 2008 - statistical relevance between sites and results through principal component analysis (PCA) Finally, these results, where applicable, were compared to both national and international standards for human and ecological use. The results indicated that the water quality levels exceeded the guideline values of national and international standards for the following uses: drinking water, certain industrial activities, watering of certain livestock and crop types as well as aquaculture. It was also found that the water quality was acceptable for certain activities (e.g. recreation) only if precautions and further analysis are performed. The guideline values of national water quality standards for ecological status were also exceeded, while the PAI results indicated that the ecological category (EC) for the Wonderfonteinspruit is a D which indicates that the state of the water quality in terms of the ecology is fair. The sediment quality of the Wonderfonteinspruit was determined by ICP-MS. The metal composition of the sediment was compared to that of other rivers and the following indices were applied: enrichment factor (EF), contamination factor (CF), pollution load index (PLI) and geo-accumulation index (Igeo). It was found that the sediment composition is comparable to that of other rivers impacted by gold mining and that uranium, cobalt and nickel enriched the sediment according to the indices. Biotic indicators that were assessed included fish, diatoms and invertebrates. The fish health assessment index (HAI) was applied to fish caught in the Donaldson Dam. The muscle tissue was also removed and its metal concentration was determined by ICP-MS. Thereafter, the edibility of the fish muscle tissue was determined and the following indices were applied: condition factor (CF), hepatosomatic index (HSI), gonadosomatic index (GSI) and spleen somatic index (SSI). The diatom community composition was assessed by applying the Biological Diatom Index (BDI), Specific Pollution Sensitivity Index (SPI) and the percentage pollution tolerant valves (%PTV). The Macroinvertebrate Response Assessment Index (MIRAI) was applied in order to determine the state of the macroinvertebrate community. The fish assessment indicated that arsenic contamination may negatively impact the health of consumers. Diatom indices indicated that the EC of the Wonderfonteinspruit is a D/E which indicates poor water quality; likewise, this is supported by the MIRAI results as the EC for MIRAI was a D which indicates that the river is largely modified. The investigation into the water use of the Bekkersdal community, with a special focus on the use of the Wonderfonteinspruit, was achieved through the use of questionnaires that were distributed in both formal and informal sections in Bekkersdal. The research forms part of a larger Integrative Multidisciplinary study and was given ethical clearance under the NRF Community Engagement Project (see Ethical Clearance: no. FH-BE-2013-0014. The National Research Fund (NRF) provided the funding for the research, the views expressed is that of the author and not those of the NRF. The aim of the questionnaire was to determine the following aspects in terms of the community of Bekkersdal: - Demographic details, such as language preference, employment status and age distribution. - Current water use practices . - Use of the Wonderfonteinspruit. - Future water use of the Wonderfonteinspruit. - Water quality perceptions of the Wonderfonteinspruit. - Field notes that included any relevant observations of the fieldworkers. The unemployment rate of the Bekkersdal community was found to be high (78.20%) and 86.40% of the residents are South African citizens. The community relies heavily on municipal provision of sources of water with 100% of the respondents indicating that it is their primary source of water. However, several issues were identified in terms of municipal water supply in the community. Some 10.14% of the residents indicated that they make regular use of the Wonderfonteinspruit (in particular the Donaldson Dam) most often for drinking water, laundry and washing of cars, etc. Regarding the state of the Wonderfonteinspruit, the overall viewpoint of the Bekkersdal community was that it is largely polluted with sewage, litter and mining waste. However, some 87.80% of the residents expressed their willingness to participate in environmental clean-up initiatives in their area. The link between the ecological state of the Wonderfonteinspruit and human health and wellbeing was explored through the use of spider diagrams where rank scores were assigned to both index results and human water quality use categories. These were compared and it was found that ecological indicators are more sensitive than human water quality use scores and therefore can aid in acting as early detection indicators of possible negative impacts on human health and wellbeing. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
4

Assessing sewage disposals in soft-bottom habitats / Evaluación del vertido de aguas residuales urbanas sobre hábitats de fondos blandos

de-la-Ossa-Carretero, Jose Antonio 02 December 2011 (has links)
No description available.
5

Using macroinvertebrate community composition to distinguish between natural and anthropogenic sedimentation

Schutt, Amanda E. 07 September 2012 (has links)
Excess fine sediment from human activity is a major pollutant to streams across the U.S.; however, distinguishing human-induced sedimentation from natural fine sediment is complex. The U.S. Environmental Protection Agency recently implemented a protocol for the quantitative field assessment of human-induced sedimentation using measurements of stream geomorphology. Macroinvertebrate community composition, streambed sediment stability, and sediment composition were studied at 49 sites in the James River watershed in central Virginia. Sediment composition was found to be a stronger driver of community composition than sediment stability. Although I was not able to show that macroinvertebrate metrics were related to sediment stability independently of actual fine sediment composition, some metrics, including percent Ephemeridae, a family of burrowing mayflies (order = Ephemeroptera) show promise as valuable tools for regional biologists and resource managers to discriminate among streams considered impaired for sediment pollution.
6

Évolution et santé des herbiers à Zostera noltii dans le bassin d'Arcachon à travers la dynamique de la macrofaune benthique associée / Evolution and health of seagrass Zostera noltii in Arcachon bay through the dynamics of associated benthic macrofauna

Do, Van Tu 17 September 2012 (has links)
L’objectif général était d’évaluer la réponse du macrobenthos à la dynamique d’un herbier marin à Zostera noltii (colonisation, maturation, destruction, restauration), dans le Bassin d’Arcachon, une lagune du sud-ouest de la France. Quand l’herbier commence à se développer, la structure de la macrofaune diverge immédiatement entre habitats d’herbier et de sables nus, sans cependant que les indice biotiques testés (BENTIX, BOPA, AMBI) varient. De même, la population du bivalve dominant, la coque (Cerastoderma edule), souffre du développement de l’herbier. Sa communauté parasitaire (trématodes) est modifiée, sans que cela n’influe sur la dynamique des coques. A l’échelle du Bassin, le développement de l’herbier (considéré comme un signe de “bonne santé”) a été comparé à la santé de deux bivalves endogés dominants, la palourde japonaise (Ruditapes philippinarum) et la coque (C. edule), évaluée en termes de prévalence de maladie. Aucune corrélation n’existe entre le taux de recouvrement d’herbier et la prévalence de trois maladies (trématodiase, perkinsose, maladie du muscle marron). Entre 2002 et 2010, la surface d’herbier a diminué de 1/3. En termes de structure de communautés et d’espèces dominantes, peu de différences sont notées au sein de chaque année (entre les 12 stations) et entre années, indépendamment du déclin de l’herbier. Parmi les indicateurs biotiques, l’indice multivarié MISS est en adéquation avec la relative similarité de la structure de la macrofaune benthique entre les groupes discriminés par l’analyse MDS. En 2005, des activités de dragage dans le Bassin d’Arcachon ont abouti à l’enfouissement de 0,32 km2 d’herbier à Z. noltii. La structure du macrobenthos a été immédiatement modifiée sans retour à l’état initial sur les zones couvertes de sable. En revanche, le macrobenthos (endofaune) s’est rapidement rétabli dans les zones couvertes de vase alors que l’herbier n’a commencé à se développer qu’au bout de 5 ans après les travaux. Le dernier chapitre de cette thèse donne un bref aperçu des connaissances actuelles sur les herbiers vietnamiens et des possibles travaux scientifiques à mener. / The overall objective was to assess macrobenthos response to marine Zostera noltii seagrass dynamics (colonization, maturation, destruction, restoration), in Arcachon Bay, a French Southwestern lagoon.When seagrass starts to develop, the structure of macrofauna community immediately diverges between sand and seagrass habitats, without however modifying tested biotic indices (BENTIX, BOPA, AMBI). As well, population of the dominant bivalve, the cockle (Cerastoderma edule), suffers from seagrass development. Their parasite (trematode) community are impacted, but not sufficiently to explain cockle deficit in seagrass.At the scale of the Bay, seagrass development (considered as a sign of “good health”) is compared to the fitness of the two dominant infaunal bivalves, the Manila clam (Ruditapes philippinarum) and the cockle (Cerastoderma edule), measured in terms of disease prevalence. There was no correlation among seagrass cover rate and the prevalence of three diseases: trematodiosis, perkinsosis and Brown Muscle Disease.Between 2002 and 2010, seagrass cover decreased by 1/3. When looking at community structure and dominant species, there were moderate differences within (among 12 stations) and among years, independently of seagrass decline. Among biotic indicators, multivariate index MISS was in adequation with the relative similarity of macrofauna structure among groups discriminated by MISS analysis.In 2005, dredging activities in Arcachon Bay led in burying 0.32 km2 of Z. noltii. Macrobenthos structure was immediately modified and did not recover in places buried by sand. Conversely, macrobenthos (infauna) recovered rapidly in areas cover by mud, while seagrass began to develop again five years after work. The last chapter of the thesis provides a brief insight of the seagrass in Vietnam, the actual knowledge and what could be investigated.

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