Dissertations / Theses on the topic 'Water quality – KwaZulu-Natal – Umgeni River'

This study assessed the quality of the Umgeni River in Durban South Africa seasonally from March 2011 to January 2012, according to standard protocol. Water samples were collected from Inanda dam-U5, KrantzKloof Nature Reserve-U4, New Germany-U3, Reservoir Hills –U2 and River mouth – U1 areas of the Umgeni River. A two-step tangential flow filtration (TFF) process was setup for the concentration of viruses from water samples. Virus like particles (VLPs) was detected using electron microscopy. Canonical correspondence analysis (CCA) was used to statistically evaluate the data sets. All water samples had turbidity values which exceeded the South African water quality guideline value of 0.1 NTU for turbidity. Large seasonal variations in BOD5, COD and conductivity levels were observed. Chloride concentrations were extremely high at point U1 (19234 mg/ℓ) Cl during summer. Total heterotrophic bacterial (THB) population was highest at 13.67 x 106 cfu/100ml (U1 – summer). Enterococci (EC) concentrations were detected at points U1, U2, U3, and U4 during the autumn and spring period. pH, electrical conductivity, temperature, and turbidity positively correlated with the microbial communities, and were the key parameters responsible for water pollution according to CCA. Most water samples contained high populations of somatic (659 pfu/mℓ, U1 – summer) and F-RNA coliphages (550 pfu/mℓ, U2 – summer). VLPs were detected throughout all seasons, with point U1 (summer) having the highest population of 2086 VLP/mℓ. Several presumptive viruses including Adenoviridae, Picornaviridae, Poxviridae, and Reoviridae were detected based on their morphologies. Six cell culture lines were used to determine cytopathic effect (CPE) of the VLPs. VLP samples produced CPEs on the Vero, Hek 293, Hela and A549 cell lines. Integrated cell culture (ICC) - PCR confirmed the presence of infectious VLPs in the river water samples. Adenoviruses, Enteroviruses, rotaviruses and Hepatitis B viruses were detected and quantified in all water samples by nested PCR/RT-PCR and Real-Time PCR respectively, against positive control viruses. These results indicate the potential of viruses in the water samples especially from the lower catchment areas to infect the human hosts throughout the year. These observations have public health care implications and establish a need to monitor the viral population in addition to traditional water quality indicators.
Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2013.

Dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Environmental Health, Technikon Natal, 2001.
The debate surrounding mercury pollution of the river system below Thor Chemicals in Kwa Zulu Natal, South Africa has been of concern to the people of the region for several years. No scientific assessment of Mercury pollution has been carried out to date, other then a study conducted by Johnston et al. (1991) in 1990 in an area restricted to within 5 kilometres of the plant. Due to elevated levels being detected directly below the plant, Johnston et al. (1991) have expressed concern that this could result in the mobilisation of Mercury into the ecosystem and possibly threaten the Ecology of the Inanda Dam which is located approximately 20 kilometres south of Thor Chemicals which is a major reservoir for Durban. Added to this, the community residing in the area has expressed a great deal of concern and the matter was taken up in parliament in 1998. These factors provide impetus for a follow up study to determine the extent of mercury transformation into the higher trophic levels in the area surrounding Thor Chemicals. In order to quantify the extent to which mercury has become mobilised in the ecosystem and to identify possible pathways of exposure to the community, samples of sediment, algae, cattle hair and fish were taken at ten sample sites. These sample sites were selected at intervals along the Mngceweni and Umgeni River. The first sampling site was situated below Thor and the final sample site was located at the head of the Inanda Dam. Sediment, algae, cattle hair and fish were specifically chosen as they are considered to be reliable indicators of mercury pollution and mobilization. Fish,form an important part of the diet of the community residing in the study area. Mercury concentrations for the above parameters, were compared to mercury concentrations found in the control area, upstream from Thor, as well as to international and local standards. Composite sediment samples taken at the first sample site, within 500 metres of Thor Chemicals, revealed a mercury level of 54j.lg/gram. Mercury concentrations detected in the remainder of the composite sediment samples were significantly lower and revealed similar levels of magnitude throughout the rest of the study area. The higher concentration of mercury in the sediment at the site directly below Thor Chemicals may be attributed to a high
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The health and life expectancy of populations in developing countries is largely determined by the availability of good quality drinking water. Boreholes and springs generally provide water of better microbiological and physical quality than surface water sources, however, they may cause health and aesthetic problems due to chemical constituents dissolved out of the host rock. As part of a pilot study to assess the health-related quality of community water supplies, samples were taken from two Quaternary catchment areas in KwaZulu-Natal. The Umkomazi catchment area is located inland from Amanzimtoti, while the Umfolozi catchment area is located north-east of Ulundi. The geology in these areas is significantly different. The Umkomazi area is predominantly underlain by basement rocks of the Natal Structural and Metamorphic Province, while the Umfolozi area is underlain by sedimentary rocks of the Karoo Supergroup. Geographical information systems (GIS) were used to examine the influence of lithology, rainfall and landuse activities on groundwater quality. Major ion analysis of groundwater samples from the Umkomazi area revealed a linear relationship between borehole and spring concentrations. Dwyka Tillite was found to produce water with the highest concentrations of major ions, while Karoo dolerite produced water with the lowest concentrations of major ions. Samples from basement rocks and Natal Group contained intermediate concentrations of major ions. In the Umfolozi area Karoo dolerite samples showed the lowest concentrations of major ions, while the Vryheid Formation and Dwyka Tillite produced the highest borehole and spring concentrations, respectively. High salinity levels in sedimentary rocks may be due to marine influence during deposition. Piper diagrams show relative enrichment of major cations and anions and Stiff diagrams showed characteristic patterns. Fluoride is associated with siliceous basement rocks and related to calcium concentrations through the solubility of calcium fluoride. The trace metals, manganese, iron and zinc were found to cause significant aesthetic problems and possibly health problems in sensitive individuals. These constituents are derived from weathering of bedrock and possibly from the corrosion of metal pipes. There is an inverse relationship between mean annual rainfall (MAR) and electrical conductivity (EC), except near the coast where windblown salinity increases with rainfall. Nitrate, ammonium and E. Coli contamination are linked to landuse activities such as occurrence of human and animal excreta near the water source and the proximity of pit latrines. It is recommended that rural communities be educated about the nature and importance of groundwater quality.
Thesis (M.Sc.)-University of Natal, Durban, 1998.

This study represents an integrated and holistic assessment of the eziMbokodweni Estuary’s water and sediment quality. The estuary was once relatively un-impacted but now flows through a highly anthropogenically-modified catchment, comprising industrial and residential developments (formal and informal), and the eziMbokodweni Wastewater Treatment Works, furthermore the floodplain has been completely transformed to accommodate the Amanzimtoti golf course. Flow from the highly degraded Isipingo River and Estuary is occasionally diverted into the eziMbokodweni and the Southern Sewage Works Outfall, one of the largest deep sea sewage outfalls in the eThekwini Municipality, is located at sea, approximately 1.5 km south of the estuary mouth. Estuarine health can be studied on various fronts, in this study, the following variables were monitored in the water and sediment columns, seasonally for spring and neap tides: heavy metals, nutrients, bacteria and selected physico-chemical parameters. The results demonstrated that the eziMbokodweni catchment was a major contributor of heavy metals and nutrients to the estuarine system. The quantity of the majority of heavy metals and nutrients transported by the river at the upper estuary exceeded the amount exported to sea at the estuary mouth-nearshore interface, resulting in the estuary accruing large quantities of material seasonality. It was noted that the nearshore waters are enriched, as a variety of heavy metals and nutrients entered the estuary mouth during flood tide episodes. A range of heavy metals were detected within the sediment profiles obtained from the estuary, with fine to medium grained sediment exhibiting greater heavy metal content, in some cases, multi-fold higher than that detected in medium to coarse grained sediment. Geochemical indices were employed to ascertain the extent to which these metals constituted a pollution threat to the environment. The contamination factor calculated for all sediment layers and sampling sites implied low contamination. The enrichment factor calculated for the majority of heavy metals alluded to natural causes while some heavy metals exhibited significant to extremely high levels of enrichment thus implicating anthropogenic causes as likely sources of these heavy metals. The degree of contamination of the estuary was classified as low. Overall, the heavy metal and nutrient content detected in the sediments were low as compared to the large quantities detected from the budget. This indicates that natural mechanisms exist which facilitate the utilization or removal of these heavy metals and nutrients from the estuary. It is proposed that the most significant manner by which these heavy metals and nutrients are eliminated from the estuary is through episodic flood events that scour and strip fine grained sediment from the estuary bed. The pH assessment of the estuary revealed that this environment was slightly basic through most of the year with mildly acidic conditions noted during winter. The average Dissolved Oxygen levels were within acceptable levels, with the exception of winter when levels were very close to hypoxic conditions. The average Total Dissolved Solid content indicated that the estuary was compliant with the target water quality range for domestic use on selected seasonal-tidal cycles, and the average Electrical Conductivity levels were compliant with the ideal target water quality range for aquatic ecosystems and domestic use as per the South African water quality guidelines (DWAF, 1996a-e). A salinity gradient was evident in the estuary, as salinity levels decreased with distance from the estuary mouth. The saline nature of the lower estuary provided for the flocculation of material, which was alarming as large quantities of heavy metals and nutrients were detected in the estuary. The lower estuary is therefore susceptible to contamination due to the salinity regime and the dominance of fine grained sediment. The demand for oxygen in the estuary was high during summer, autumn and spring, and within acceptable levels for natural waters during winter. Extremely high levels of Chemical Oxygen Demand were recorded in the estuary which provides prime growth and survival opportunities for bacteria. This correlated with the results from microbiological investigations as high levels of bacteria were noted within the estuary, in both the sediment and water columns. The detected quantities of Total Coliforms, Faecal Coliforms and Escherichia Coliforms exceeded the target water quality thresholds for domestic and full contact recreational use. While at selected sites, the recorded Faecal Coliforms and Escherichia Coliforms levels were deemed compliant for intermediate contact recreational use. However, these sites were not compliant throughout the sampling period. Overall, the upper and mid-estuary exhibited greater counts of bacteria, in both the sediment and water column, than the estuary mouth and was attributed to factors such as flushing, sediment particle size, salinity and the ‘dilution effect’. Furthermore, the sediment of the eziMbokodweni Estuary is serving as a reservoir for bacteria. A number of options have been proposed to improve the degraded state of the eziMbokodweni Estuary and are ultimately aimed at curbing the anthropogenic input of these contaminants. The insight gained from this study provides the database from which more integrated and holistic estuarine management strategies can stem, that are applicable not just to the eziMbokodweni Estuary but estuaries in general.
M.Sc. University of KwaZulu-Natal, Durban 2013.

The Umdloti River is relatively small but very important system that is located northeast of central Durban. This river flows pass the coastal town of Verulam and finally into an open/closed estuary, the La Mercy estuary. This fluvial system has a concrete gravity dam that is built in the upper reaches, the Hazelmere Dam, which supplies water to the north local council and surrounding districts under the supervision of Umgeni Water. The river is characterized by human activities, especially urbanisation and industrialization in the middle reaches and intensive agriculture (vegetables, sugar cane and banana plantations) along the catchment. The influence of anthropogenic factors within this catchment results from the dam construction, informal settlements, both commercial and subsistence agriculture, intensive industrial activity, accelerated urban developments, and recreational uses. Consequently there has been considerable concern regarding the impacts of these factors together with natural influences on the water quality and health status of this fluvial system. In this study water samples were taken and analysed for the following variables: nitrites; nitrates; ammonia; pH; Escherichia coli; sulphate; phosphate; total dissolved solids; chemical oxygen demand; biological oxygen demand; calcium and magnesium. The results indicate that the middle and the lower reaches of the Umdloti River are most impacted. Further, results from a questionnaire survey indicate that natural and human induced impacts have impacted negatively on the health status of the Umdloti River. The questionnaire survey also revealed that respondents benefited positively from the construction of the dam whilst the expropriation of land for the construction of the dam itself created much resentment to the prior land owners. The water quality data and the questionnaire analysis indicate overall natural and human induced impacts have had negative effects on the Umdloti River and the La Mercy estuary. It is necessary that local municipal authorities introduce corrective catchment management practices (outlined in the final chapter of the study) to enhance the water quality and health status of the river.
Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

The Reserve concept, introduced in the National Water Act, has led to an increasing use of biomonitoring techniques to assess the current ecological status of rivers in South Africa. The ecological status of a river provides vital information necessary to establish the amount and quality of water needed by the aquatic ecosystem. If the amount and quality of water is inadequate, then the water resource will not be able to provide the necessary goods and services to their respective water users. The biomonitoring of rivers gained impetus with the establishment of the River Health Programme (RHP) and its various objectives. The RHP led to the development and refinement of a range of biomonitoring indices to assess various components of the aquatic ecosystem. The components used to assess the current ecological status of a river include the physical habitat, riparian vegetation, water quality, as well as the macro-invertebrate and fish communities. The Mvoti River, in the vicinity of Stanger, is subjected to extensive water abstraction, which is then utilised for irrigation, industrial use, urban water requirements and various domestic uses by informal settlements. Previous studies on the river indicated that it is in a severely degraded state, especially below the confluences of the Nchaweni and Mbozambo rivers. Thus, this assessment of the current ecological status of the Mvoti River was undertaken to possibly identify the main causes of the degraded state. The study was undertaken during the high (February) and low flow (August) periods in 2005. Selected monitoring sites included sites used in previous studies on the Mvoti River as well as sites on the Nchaweni and Mbozambo tributaries. The methodology for this study was to implement the various indices used in the RHP for the different ecosystem components. The habitat indices implemented in this study were the Habitat Quality Index (HQI) and Integrated Habitat Assessment System (IHAS). Physicochemical water analyses were done during each sampling period to assess the water quality against the South African Water Quality Guidelines. The biotic indices used included the South African Scoring System 5 (SASS5) index to assess the macro-invertebrate community and the Fish Assemblage Integrity Index (FAII) to assess the fish community. Additionally, the newly developed EcoStatus indices for the fish and macro-invertebrate communities were implemented on the available fish and macro-invertebrate data. These indices were developed mainly to be used in Reserve determination assessments, where the assessments are built around the integration of all ecosystem components into a single value for the ecological status. The fish index is termed the Fish Response Assessment Index (FRAI) and the macro-invertebrate index the Macro-invertebrate Assessment Index (MIRAI)…. Multivariate statistical analyses were performed on the water quality as well as the macroinvertebrate and fish communities to establish any temporal and spatial trends together with any dominating water quality variables responsible for species composition at the different sites. PRIMER and CANOCO computer software were used to construct hierarchical clusters and NMDS plots for the biotic communities, while RDA and PCA bi-plots were used to represent the water quality variables and their effects on the biotic community structure. The Mvoti River is in a seriously degraded state and this degradation was particularly evident during the low flow period below the Sappi Stanger mill and the Stanger Sewage works effluent discharge points. The degraded state of the river is caused by the multitude of impacts on the river, which includes the local land-use, upstream land-use and effluent discharges in the vicinity of Stanger. The water quality in the vicinity of Stanger was in a poor state during the low flow, while the high flow was only slightly better. The upstream site is in a fair condition but, after the Nchaweni and Mbozambo rivers enter the Mvoti River, the water quality decreases. The variables found to be problematic included microbiological variables, chlorides and electrical conductivity in the Mvoti River. High nutrient values were found together with very high electrical conductivity in especially the Nchaweni River tributary. The lower Mvoti River contains very little habitat of good quality to support the biotic communities. The habitat is generally degraded due to the destruction of the riparian zone and the dominance of alien vegetation in the form of reeds. This, together with land-use and water abstraction activities, has caused high sediment loads in the lower Mvoti River which are continually moving. The IHAS and HQI results indicated the habitat in the lower Mvoti River is in a modified condition. The statistical analysis of the macro-invertebrate data showed that a definite spatial variation existed while no significant temporal variation was identified. There is a difference in the community structure between the Mvoti River and its tributaries, with the tributaries containing a very poor diversity. This lowered species diversity was attributed to the effects of, specifically, chlorides on the community structure but the origin of the chlorides could not be linked specifically to the Sappi Stanger mill’s activities. The SASS5 was similar with the Mvoti River sites having slightly higher scores, placing it in either a B or C class while most of the tributaries had a Class D. The community structure in the tributaries responded to nutrients and chlorides and these variables reduced the numbers of sensitive species and allowed hardy taxa to flourish. The results of the MIRAI index provided the same categories as identified by the SASS5 index. The fish community structure showed the same spatial differences identified in the macroinvertebrate communities, with the tributary sites containing different community structures than those found in the Mvoti River. The Mvoti River fish community is in a modified state with the majority of fish sampled being tolerant with very few sensitive species present. The FAII scores for the Mvoti River was a Category C, while the tributary sites scored a Category D or lower. The fish community is affected by the poor water quality, habitat and flow modifications in the lower Mvoti River. The FRAI index provided the lower Mvoti River and its tributaries with the same categories as identified with FAII. Overall, the Mvoti River is in a seriously degraded state with even the reference site being subjected to impacts that could potentially be harmful to the ecosystem. The ecological state of the river decreases as it moves past Stanger and is subjected to the impacts from the Nchaweni and Mbozambo rivers in the form of nutrients and salinity concentrations. The impacts on the Mvoti River have a multitude of different sources and if the aquatic ecosystem is to improve, only a collective effort will be of any value.
Prof. V. Wepener

The Isipingo River and Estuary system located in the province of KwaZulu-Natal, although relatively small, has been subjected to the impacts of intense development within the catchment. The catchment is characterized by informal and formal dwellings and intensive industrial activities in the lower catchment and in close proximity to the estuary. Significant modifications to the hydrology of the system has occurred as a result of the diversion of the Umlazi River (which previously merged with the Isipingo River at the estuary mouth), canalization of the lower portion of the Isipingo River flowing through the Prospecton Industrial Area and the development of the Diversion Works system (to regulate flows to the lower Isipingo River), removal of riparian vegetation, encroachment onto the river and estuarine floodplain, and land reclamation through the infilling of wetlands all of which has culminated in a deterioration of the functionality and health of this system. The main aspects of this study focus on water and sediment quality, material flux between the estuary and the sea and the management of the system. The water quality variables covered as part of this dissertation include physical, chemical (nutrients and heavy metals) and microbiological (faecal coliforms) components. The water quality of the river and estuary presents a risk to human health and the concentrations of heavy metals generally exceeded the South African Water Quality Guidelines that prescribes target levels, implying potential negative impacts to aquatic health. The Isipingo system exhibited signs of eutrophication with phosphorus concentrations in excess of the target level to prevent eutrophication. Excessive water hyacinth growth was visible during most of the field surveys. A geochemical assessment of heavy metals in surface sediments of the river and estuary was also undertaken. The results indicate that although the presence of several metals were undetectable at certain river sites, the concentrations of those heavy metals present increased in a longitudinal direction from the river to the estuary. The contamination factor analysis for all metals indicated low contamination except for selenium. The riverine sites yielded moderate enrichment by some heavy metals in both seasons. The degree of contamination for each site with the exclusion of selenium was low. The inclusion of selenium in the assessment raises the estuary to a considerably contaminated status in the wet season. The analysis suggests that the enrichment of the system by selenium is due to an anthropogenic source. The Geo-accumulation Index places the sediment in an overall unpolluted category. The study conducted on the net exchange of heavy metals and nutrients between the Isipingo Estuary and the adjacent marine environment (i.e. Indian Ocean) demonstrates that significant quantities of the suite of heavy metal analysed are exported on an annual basis while copper, nickel and zinc are imported into the estuary. Significant quantities of ammonia and nitrates are exported annually from the Isipingo Estuary while a net annual import of phosphorous is observed. The variation in the quantity and concentration of nutrients exported during the seasons may be attributed to anthropogenic source. The import of nutrients from marine sources can accumulate in the estuary and contribute to eutrophication of the Isipingo Estuary. This study also demonstrated that although the ebb flow has a much longer duration than the flood flow, the flood velocities observed were generally greater than the ebb velocities. The final part of this research identifies other environmental problems experienced in the Isipingo catchment. The following issues are identified as directly or indirectly contributing to stress and deterioration of the water quality of the Isipingo system: reduction in water quantity, poor water quality, moderate enriched sediment, loss of habitat integrity, species diversity and invasive alien vegetation and uncontrolled solid waste. A Water Quality Management Plan including management objectives, strategies and action plans to address the direct and indirect factors influencing the system are proposed. A water quality monitoring program is also proposed for the Isipingo River and Estuary. The adoption and execution of the water quality management plan and monitoring program will assist in the prevention of further degradation of the system and will be a stepping stone toward improvement.
Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2013.

The inefficiency of South Africa’s previous legislation that regulated the operation and closure of mining activities, has resulted in too many mines being abandoned without adequate rehabilitation (Naidoo, 2017). Therefore, currently, the State has taken a responsibility to identify all these abandoned mines, assess and rehabilitate them in order to mitigate their environmental impacts, mainly the acid mine drainage (AMD) impacts. A defunct colliery in Glencoe, which ceased its operation in 1973, is one of the mines that was identified as an abandoned mine. This mine is located on the upper Wasbank catchment area in KwaZulu-Natal and study was conducted in order to determine whether this defunct colliery has any negative effects on the water quality of this catchment area. A zone above the mine shaft of the defunct colliery was identified and considered as a pristine zone, which was then used as a reference zone, and three more zones were identified, adjacent and below the mine shaft, named sampling zone B, C and D in order to assess the trend of water quality indicators and therefore to determine whether the defunct colliery is contaminating this catchment area or not. Each zone had distinct sampling points within the zone, ranging from one to four sample points per zone. Water quality of this catchment area was tested on a monthly basis during the wet season (December 2017 to March 2018) and the dry season (April 2018 to July 2018). The parameters that were tested in the field were pH, electrical conductivity, and temperature. Furthermore, once a season, water samples were collected from each sampling point in order to determine the concentration of dissolved ions. All results were analyzed against the results of the reference zone and furthermore, against the South African Water Quality Guidelines for livestock farming and domestic use. The conclusion drawn from these results is that this catchment area is altered by mine drainage from the defunct colliery. However, it seems that mitigation measures designed by previous miners are effectively treating the AMD generated which has resulted in the neutralization of this acidity such that any decant from old mine works into the Wasbank River is slightly alkaline. Furthermore, based on SAWQG, the study concluded that this catchment is within the water quality standards for livestock farming and domestic use. However, there are minor restrictions to certain specific uses because of its salty state. Subsequent to the findings of this study, the defunct colliery can be considered as low priority of future rehabilitation efforts due to the state of water quality of the surrounding drainage
MT 2019

Submitted in partial fulfillment for the Degree of Master of Applied Sciences in Biotechnology, Durban University of Technology, Durban, South Africa, 2017.
The study aims to assess and compare the concentration of microbial contaminants, their sources and distribution in surface water and sediment, and to determine the impact of seasonal variations and corresponding risks of faecal contamination using conventional and molecular methods. Historical data analysis was conducted using E. coli values from the eThekwini Water and Sanitation (EWS) department for 66 months (2009-2014). E. coli and Enterococci were analysed in surface water and sediment samples using the mFC/ spread plate and Colilert-18 (IDEXX) methods. The impact of seasonal variations was assessed using E. coli and Enterococci data collected during rainfall and no rainfall events, using an auto-sampler and sediment trap in parallel. Conventional standard membrane filtration methods using mFC agar, Slanetz & Bartley/ Bile Esculin and Brilliance E. coli selective agar were compared to the enzymatic Colilert-18 and Enterolert (IDEXX) test methods along the Isipingo and Palmiet Rivers. In addition, comparison of the analytical performance of droplet digital PCR (ddPCR) and qPCR for the detection of Salmonella targeting ttr gene in river sediment samples collected from the four sites of the Palmiet River in Durban, South Africa was done. In order to assess the public health risk associated with exposure of men, women and children to microbial pathogens in polluted surface water during recreational activities, the QMRA tool was employed in relation to the risk exposure to pathogenic E. coli, Campylobacter, Salmonella and Shigella. Also, the risk associated with crop irrigation (on farmers) as well as the consumption of crops irrigated with surface water from the Isipingo river was determined. Analysis of the historical data gave a baseline of the two rivers of interest, thus helps understand the current situation of the rivers enabling researchers to pick up potential gaps. In this study after the analysis of the historical data it was evident that at the Palmiet river, microbial analysis must be conducted around the QRI settlements which is a major pollution source. Also, from this study it was found that sampling points situated close to wastewater treatment plants, pump stations or informal settlements were of major concern, thus were considered for the study. It was found that sediment exhibited higher microbial concentrations than surface water, which was observed in both rivers. Also, rainfall had a significant impact on microbial variability. Higher microbial concentrations (indicator organisms) were observed in surface water after a heavy rainfall as appose to when there was no rainfall. This was due to contamination that is washed off into the river and sediment resuspension. Methodology comparison revealed that Colilert-18 and Brilliance E. coli were more selective compared to mFC agar. Brilliance E. coli /Coliform agar was comparable with Colilert-18 IDEXX, which was also observed with Slanetz & Bartley and Enterolert IDEXX. However, when mFC agar was compared with Colilert-18 IDEXX, significant difference was observed. In comparison of two Molecular methods, ddPCR were found to be fully amenable for the quantification of Salmonella and offer robust, accurate, high-throughput, affordable and more sensitive quantitation than qPCR in complex environmental samples like sediments. Quantitative Microbial Risk Assessment (QMRA) relating to recreational and occupational exposure showed that children were at the highest risk of getting infected. Also, it was observed that the probability of infection upon exposure to surface water from the Isipingo and Palmiet rivers was significantly high, hence exceeded the WHO guidelines values. Risk assessment on crops revealed that pathogenic bacteria may pose a risk to the consumer, however, a 9-log reduction may be achieved according to the WHO multi-barrier approach which involves proper washing and proper cooking of the crop before ingestion. Overall the sampling points that had the highest pollution level and constantly exceeded the WHO and DWAF guidelines at the Isipingo river were the points situated and named “Next to the WWTP”, and “Downstream of QRI” at the Palmiet River.
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Water, a fundamental and irreplaceable resource, is an all-pervasive issue that underpins the social fabric of every society. Rapid population growth and expansion of human activities increases the amount of waste and pollution generated and many local authorities are encountering serious water pollution problems, often concentrated in the lower reaches of catchments and adjacent coastal areas. This problem is predominantly acute in urbanized catchment areas, where waste is concentrated into localized areas, and the authorities are constantly under pressure to provide adequate management and mitigation measures. The Palmiet River system, located in the northern fringe of the city of Durban and draining the highly industrialized Pinetown region in KwaZulu-Natal, South Africa, illustrates a system that has been altered due to human impacts, particularly in its headwaters where the industrial sites are located and, in the lower catchment where a densely populated informal settlement occurs. A range of chemical and biotic indicators were monitored seasonally and these confirm the influence of the aforementioned human impacts on the quality of the Palmiet River system. Results from the present study were compared with studies conducted over a period of two decades and clearly demonstrate a pattern of increasing pollution loads for the upper and lower parts of the catchment. This study confirms that the Palmiet River is severely degraded in its lower reaches whilst the middle reaches of the catchment where a nature reserve is located is still in a fairly pristine condition. Additionally, the Palmiet River issues discussed in this thesis have direct impacts on the estuarine and adjacent marine ecosystems.
Thesis (M.A.)-University of KwaZulu-Natal, Durban,2005.

M.Sc. (Zoology)
The construction of the Pongolapoort Dam in 1974 has altered conditions downstream of the Phongolo River in terms of hydrology, geomorphology, water quality, and ecosystem services. Activities along the Phongolo River permit anthropogenic compounds such as pesticides used in disease control to enter the aquatic environment. This alteration of natural environmental conditions creates a need for a monitoring programme. This study aims to assess the use of Hydrocynus vittatus as an indicator organism of pollution in the Nyamithi Pan and Phongolo River. Water and sediment samples were analysed for a variety of metal elements. The physical characteristics of water samples were determined using a WTW Multi 340i multimeter. Nutrients in water were analysed using a Merck Spectroquant™ Pharo 100 Spectrophotometer. Sediment analysis was based on the standard protocols of the United States Environmental Protection Agency (2001). Physiological stress responses in Hydrocynus vittatus were determined using acetylcholine esterase, catalase, cellular energy allocation, 7-ethoxyresorufin-O-deethylase, malondialdehyde, metallothionein, superoxide dismutase, and protein carbonyls. Employing standard techniques H. vittatus was analysed for metals and organics using ICP-MS, ICP-GS and ICP-OES. Results for biological responses and bioaccumulation show significant differences between sites related to the environmental concentrations of elements. Organisms in the Phongolo River have elevated concentrations of DDT and the metabolites indicating recent exposure. Organisms from the Phongolo River are seen to be responding based on up or down regulated concentrations of biological markers. In particular, concentrations of CAT, MDA and PC are elevated in the Phongolo population with decreased AChE responses indicating toxicant exposure. Data accumulated in this study will contribute to the establishment of baseline chemical, physical and biological knowledge of the effects of contamination in South African waters.

M.Sc.
The Mvoti River is referred to as a ‘working river’ in that it is highly utilized and developed. It is also, however, in a severely degraded state according to recent ecological assessments that were carried out on the Lower Mvoti River in 2000 and 2005. Previously, this was mostly attributed to the specific activities related to a pulp and paper mill. However, findings of the abovementioned studies indicated that there are multiple stressors present in the system and to derive the combined effect of stressors in an environment affected by multiple activities, a characterization of the different contributing activities is required. Thus, this assessment was undertaken to determine the impact of one of the contributing stressors, i.e. sugar milling activities on the ecological integrity of the Mvoti River. The survey assessments, incorporating local and international accredited methods and techniques, were carried out over a high and low flow period during 2006. A BACI (before-after controlled impact)-research design was applied in this study. Four sites were selected on the Mvoti River, up and downstream of the Glendale Distillery (GDR and GDS) and the Ushukela Milling Company (USR and USS). The former sites were selected to assess the impact of a sugar mill alone and the latter to determine the combined effects of sugar milling and pulp and paper activities. Additionally, 2 sites were selected on the Amatikulu River, up and downstream of the Amatikulu Mill (AR and AS), to assess the effect of the sugar milling activities alone. This study consists of two components, namely the abiotic driver component and the biotic response component. The abiotic driver component involved the analysis of water quality, sediment and habitat quality in which physico-chemical variables of water and sediment were carried out during high and low flow periods and the habitat indices, Habitat Quality Index (HQI) and Integrated Habitat Assessment System (IHAS) were implemented. The biotic response component involved the assessment of the macroinvertebrate and fish community structures, as well as the determination of acute and chronic toxicity and mutagenicity resulting from exposure to mill effluent. The macroinvertebrate communities were assessed using the South African Scoring System Version 5 (SASS5) index and the fish communities were assessed using the Fish Assemblage Integrity Index (FAII). The toxicological assessments were carried out via the use of the Direct Estimation of Ecological Effect Potential, or DEEEP, methodology, and biomarkers.

This dissertation focussed on the Mvoti River system in KwaZulu-Natal, an important resource for the numerous towns and villages along its course. Catchment activities are varied with agriculture being the predominant activity, and industrial activities common in the lower catchment. The Mvoti River is intensively utilized, especially in its lower reaches, to the extent that it is referred to as a ‘working river’. Modifications of the chemical and physical characteristics of the system, and consequently the biological characteristics, have led to degradation of the system such that the functioning of the lower river has deteriorated in comparison to that of its pre-disturbance condition. There are three main aspects of the Mvoti system around which this dissertation is based, namely, water quality, geochemistry, and conservation of the system. The results of the water quality survey of the estuary revealed that the system is presently experiencing water which is of an inferior quality. Compared against the South African water quality standards, a majority of the parameters exceed acceptable limits and are likely to present negative impacts on aquatic health and potentially human health. Comparison of current results, and water quality data for the system dating back to 1964, revealed that this degradation is not new to the system, and the Mvoti Estuary has in fact been experiencing continued deterioration over the years. The second part of this study investigated heavy metal presence in the sediments of the lower system and elemental presence and distribution in the surface sediments of the middle and lower River respectively. Results indicated that even though selected heavy metals are present, they are of concentrations lower than those of two other South African and two other international systems they were compared with. Enrichment and contamination assessments reveal that contaminants are in all probability present as a result of anthropogenic sources. However, distribution patterns which show highest levels just after effluent disposal sites suggest that the contamination is presumably human-induced and, the predominance of larger grained sediments that do not have high adsorption capacities, suggest that contaminants are readily remobilized into the water column. The final part of this research investigates other environmental problems, and causes, both natural and anthropogenic, experienced by the estuary system. These stresses include poor water quality, reduced water quantity, sedimentation, alien vegetation invasions and loss of biodiversity. Strategies to address these issues are proposed, with the intention of improving the condition of the estuary. This is an attempt at ecological restoration, to restore the estuary to a condition as close to as possible, to its pre-disturbance condition. These strategies include controlling abstraction and discharge, eradicating alien vegetation, controlling sandmining, and improving the overall quality of the system. Also proposed is an estuary management plan (EMP) for the Mvoti system, as there is currently no plan of such a nature in place. The EMP will aid restoration attempts, increase public awareness, and via post-project monitoring and evaluation ensure the success and sustainability of any future projects. Significantly, the adoption of an EMP will be a major step towards the rehabilitation, conservation and protection of this already degraded system.
Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2010.

The South African National Water Act (NWA) (No. 36 of 1998) recognises that in order to sustain the goods and services that are provided by rivers and their associated biological communities, it is necessary to conserve the entire aquatic ecosystem. Conservation and maintenance of ecosystem functioning entails the protection of the biotic components (i.e. fish, macroinvertebrates, riparian vegetation, etc.) and ensuring that the abiotic driver aspects (i.e. required amount and variability of flow, water quality and fluvial geomorphology) are addressed and met (Malan and Day, 2003). According to the Reserve Determination methodology (DWAF, 2003), sustainable utilisation of the river resources requires proper, responsible management and that exploitation without understanding or limits, impacts negatively on the ecological processes, functions and communities, both in the present and the future. Manipulation of the flow regimes of rivers, to provide water when and where people need it, has resulted in a growing deterioration in the condition (health) of riverine ecosystems (King et al., 2000). Stressors on aquatic ecosystems originating from these anthropogenic activities, include point and non-point loadings, land use influences and changes, and stream modification. These are usually defined by the drivers of aquatic ecosystems namely the geomorphology, hydrology and water quality. In turn, the effects on the physical habitat and water quality have both direct and indirect effects on the biotic communities present and are usually defined by biological responses to these changes (Kleynhans et al., 2005). There is currently limited data available to formally propose a methodology to quantify the significance of altered flows in riverine ecosystems brought about by the abstraction or excessive release of water by industrial activities on a reach scale. The aim of this study was to determine the degree and magnitude of habitat-flow alterations caused by pulp and paper mill activities in the Elands and Mvoti Rivers and to link the related biological responses to them.
Prof. V. Wepener

M.Sc. (Zoology)
Concern has been shown by Ezemvelo KZN Wildlife for the state of the Lower Pongolo River and Floodplain due to the ever increasing urban and industrial development in the area. This increase in development poses a threat to the fish populations within the system and their ability to support the surrounding communities. Continued spraying of pesticides e.g. DDT within the area are adding to stresses placed on the fish populations through decreasing water quality. The effectiveness of environmental water flows suggested by White et al. (1984), have never been assessed by conservation authorities. This means that the authorities have been unable to fulfil their legislative obligations to establish management and conservation plans (Hughes et al., 2001). Work on the biological responses of fish to anthropogenic stressors such as organic pollutants and metals; have been conducted by a group of experts in the field of ecological health. This section of the project focusses on two fish species, Hydrocynus vittatus and Synodontis zambezensis, sampled within the study area and used for biomarkers and tissue chemical level determination. Standard techniques were applied for Organochlorine Pesticide (OCP) analysis according to Yohannes et al. (2013) and these results have been compared to biomarker responses which have also been completed following standard protocols. Results found within both fish species, show the relationship between accumulation of toxicants and biomarker responses. The highest levels of ΣOCPs where found within H. vittatus at (Mean ± SE) 1101.61 ± 610.97 ng/g lipid weight, the highest constituent being technical grade Dichlorodiphenyltrichloroethane (DDT). High levels of ΣDDT were also found in S. zambezensis, but were lower than levels in H. vittatus and these levels correspond with positioning of each species within the food web. H. vittatus occupies a much higher level in the food web as they are top predators and S. zambezensis falls lower down on the food web due to their reliance on detritus and only small invertebrate species for food. Biomarker responses are clearly affected by bioaccumulation levels and this is especially evident within H. vittatus as Achetylcholinesterase (AChE) is greatly inhibited by high levels of ΣDDT. Changes in the level of biomarker responses are not as apparent in S. zambezensis and this is believed to be food web linked, due to differences in bioconcentration. Data collected during this study will contribute to baseline data on S. zambezensis and add to already accumulated data on H. vittatus. This new data will also help with the improvement of or alteration to already present monitoring programmes in the study area.

M.Sc.
The lower Thukela River catchment supports the highly industrialised Mandini/Sundumbili Industrial Complex, which in turn supports Tugela Rail, a textile factory, a vegetable-oil factory, as well as the Sundumbili Sewerage Treatment works. All of these industries release their wastes into the Mandini River that leads into the lower Thukela River. Another major potential impacting factor on the lower Thukela River is the Sappi Tugela pulp and paper mill that has both abstraction and discharge points in the same region. In 2004 the Department of Water Affairs and Forestry completed a comprehensive Reserve Determination study for the Thukela River. Upon reviewing the results it was clear that many of the variables assessed were of low confidence or there was not sufficient data collected within the region of the Mandini and Thukela River confluence and further downstream (Resource Unit K). Therefore the previous studies were not able to determine the degree to which the industries in the lower Thukela system impacted upon the integrity of the system. The aim of this study was therefore to assess the contributing impacts of the Tugela pulp and paper mill and other industrial activities on the ecological integrity of the lower Thukela River. This was done by through a toxicity assessment of the potential impacts of effluent and wastewater using the Direct Estimation of Ecological Effect Potential (DEEEP) methodologies. The toxicity of pulp and paper effluent from the Thukela mill and the receiving water body was compared to effluents from two other mills (Stanger and Ngodwana), assessing the water quality in relation to the input of different industrial effluents in the lower Thukela River. The general integrity of the lower Thukela River in relation to the input of different industrial effluents was assessed using the Habitat Quality Index (HQI), Habitat Assessment Index (HAI), macroinvertebrate and fish population studies. These studies were integrated to derive the Ecostatus of the lower Thukela River using the Macro-invertebrate and Fish Response Assessment Indices (MIRAI and FAII respectively). The toxicity testing (DEEEP) showed the paper mill effluent in the Mandini River was the least hazardous whilst Ngodwana effluent showed the highest potential to elicit a harmful impact on the receiving water body. The latter effluent displayed the highest LC50 values for the fish and the Daphnia toxicity tests, as well as an extremely high base-pair substitution mutagen activity. Toxicity was also found in algae at 100% raw effluent exposure. Tugela and Stanger mill effluent samples were very similar in their toxicity, except that Stanger effluent showed greater mutagenicity potential with exceptionally high values of revertants. The Tugela effluent samples showed no concerning levels of mutagenicity. The fish showed lower levels of response to the Tugela sample when compared to the Stanger sample. Thus comparatively the Thukela system is regarded to be the least at risk with regards to effluent discharge into the receiving water body. The lower Thukela River integrity assessment showed a sharp increase in temperature below the discharge point of the pulp and paper mill effluent. This was attributed to the excessive temperatures recorded in the pulp and paper effluent itself. There was further decrease in dissolved oxygen, which was due a combination of the industrial waste water in the Mandini River and the pulp and paper effluent. The increased organic content in the sediments of the lowest site situated downstream (TR5) is a combination of both reduced velocity of the stream flow entering the upper reaches of the estuary as well as increased organic material entering the river via the pulp and paper effluent and the Mandini River above TR3-D. This was accompanied by increased contribution of fine particle size sediments to the overall sediment composition. Habitat conditions were near natural at sites upstream of the Mandini River and effluent discharge confluences with the Thukela River. The exception was at TR1 as the weir results in unnatural inundation of biotopes upstream. The habitat conditions around the confluences of the Mandini River and pulp and paper mill effluent discharge are diminished with a recovery noted further downstream at TR4 and TR5. Invertebrate assessment shows the upstream sites to be natural, while the impact sites were largely to seriously modified. Once again the downstream sites (TR4 and TR5) show an improvement to recover to a moderately modified state. The fish assessment also shows a decrease in the FAII score below the impacts when compared to the integrity above the impacts. However these results are of low confidence due to insufficient sampling effort as only electronarcosis, seine and cast nets were used. The Ecoclassification assessment indicated a clear decrease in Ecostatus between the sites that are upstream of the impacts caused by the industrial effluent from the Mandini River and the pulp and paper mill effluent from the effluent discharge stream. The MIRAI also clearly indicated that the major impacts are caused by the combination of the Mandini River and the pulp and paper effluent. However there was a recovery in the river further downstream from the impacts.