Vaal River Barrage Research Articles

Aspects of the pathology induced by Spinitectus petterae Boomker, 1993 in the stomach of Clarias gariepinus (Burchell, 1822) using light and scanning electron microscopy.

Spinitectus spp. (Rhabdochonidae) are enteric nematodes characterized by annular spines. At the anterior end, these spines assist attachment and aid penetration into the host tissue. During parasitological surveys of the Vaal River system from three localities, below the Vaal River Barrage in the Vaal Dam surrounding UJ island and below the Grootdraai Dam, Spinitectus specimens were collected from the stomach lining of the sharptooth catfish, Clarias gariepinus (Burchell, 1822). Histopathological effects induced by Spinitectus petterae Boomker, 1993 on C. gariepinus has not been studied. Thus, the aim of this study was to describe the histopathology induced by S. petterae. For light microscopic examination, tissue samples with attached S. petterae were sectioned and stained with haematoxylin and eosin. Additionally, attached nematodes were also studied using scanning electron microscopy. Leukocytes were counted with the Disector principle. Standard infection parameters (prevalence, mean intensity and abundance) were calculated and compared to host parameters. Prevalence varied greatly (11.77% to 100%) between localities. Histopathology induced by S. petterae to C. gariepinus stomach (cardiac region) consisted of significant leukocyte infiltration, acute ulcerations and chronic granuloma formation. This was similar to the pathology of other Spinitectus occurring in host anterior intestine and stomach, but granuloma formation had not been previously reported and this suggests chronic infection in wild caught fish.

METALLOTHIONEIN EXPRESSION IN A PARASITIC CRUSTACEAN, LAMPROGLENA CLARIAE (CRUSTACEA: COPEPODA), ON CLARIAS GARIEPINUS (TELOESTEI: CLARIIDAE) CORRESPONDS TO WATER QUALITY.

Globally, parasites are sensitive toward environmental changes, and, in some cases, they are even more sensitive than their hosts. However, there is limited knowledge on the physiological responses of parasites and their effects on their hosts in relation to environmental degradation. In this study, metallothioneins (MTs) were isolated and compared between the ectoparasite Lamproglena clariae and its host fish Clarias gariepinus. Differences in the levels of MTs in the parasite and host were compared to physicochemical water quality variables and metals to determine if MT expression was linked with changes in water quality. Clarias gariepinus individuals were sampled from 2 sites of differing water quality along the Vaal River using gill nets and assessed for L. clariae. Gill, muscle, and liver tissue of the host and L. clariae were collected and stored in liquid nitrogen for analysis of MT. Water and sediment samples were collected for metal analysis by inductively coupled plasma-optical emission spectrometry and inductively coupled plasma-mass spectrometry. Nutrient levels and water hardness in water samples were assessed using spectrophotometry. MTs were quantified using spectrophotometry and size exclusion chromatography in the host and parasite, respectively. Infections by L. clariae differed between sites, with higher parasite intensity at the unpolluted Vaal Dam site. Concentrations of MT in host tissues and L. clariae were significantly higher at the polluted site, below the Vaal River Barrage, compared to the Vaal Dam site. Parasite MT concentrations were significantly lower compared to concentrations in the liver and gill tissue of C. gariepinus individuals. In conclusion, differences in the concentrations of MT and infection biology of L. clariae reflected the state of the environment and support the usefulness of this parasite and other Lamproglena spp. as bioindicators.

Emfuleni’s wastewater crisis, 2018-2021: The history of a Vaal sub-catchment problem

In 2018 the collapse of the wastewater infrastructure of Gauteng’s Emfuleni Local Municipality was responsible for a severe fish-kill in the Vaal River Barrage. Even communities downstream of the Barrage were affected. The disaster was most evident at the riverside holiday town of Parys, tourism operations on the riverbank in the Vredefort Dome World Heritage Site and the Bloemhof Dam. Emfuleni’s crisis was the result of almost two decades of delays and underinvestment in the maintenance and upgrade of a local wastewater system earmarked for regional service delivery.Today’s Emfuleni has an illustrious history, dating back to the founding of the industrial towns of Vereeniging (1891) and Vanderbijlpark (1943). Both are situated downstream of where the Klip, Blesbokspruit and Suikerbos rivers fork into the Vaal River. Thanks to local coal mining, electricity generation and copious water supplies, industrial development thrived in the twentieth century.The 1994 demise of South Africa’s white-ruled governance system paved the way for a post-apartheid non-racial democracy. At this time there were significant changes in governance, demographics and economic development. Local population growth and the concomitant regional post-industrial development continue to have a profound impact on the Vaal River Barrage and the downstream communities.This study highlights the Integrated Vaal River system, the historical origins of today’s Emfuleni, and culminates with a discussion on the disaster of 2018 and its aftermath up until 2021.

Host selection and notes on the distribution of Chonopeltis australis Boxshall, 1976 in southern Africa

The parasite Chonopeltis australis Boxshall, 1976 has been recorded from tributaries of the Orange-Vaal River System. It is host-specific, preferring the cyprinids Labeo capensis (Smith, 1841) and Labeo umbratus (Smith, 1841). Sampling was conducted between spring 2016 and autumn 2019 at various sites on the main stream of the Vaal River. The current study considers current ecological data and compares these to historic data. The species produces a single cohort, with overwintering eggs and adults. The infection of L. capensis peaks in autumn. Parasites aggregate on larger hosts that occur in riverine habitats, but can succeed in shallow impoundments with suitable hard surfaces for egg deposition. This parasite exploits changes in ecological conditions and host biology in order to survive, but will only choose between these two host species where they aggregate on larger hosts. The increased pollution in the Vaal River Barrage and downstream has had an impact on the occurrence of C. australis and it is possibly extirpated in polluted parts of the river.

Parasites and pollution: the effectiveness of tiny organisms in assessing the quality of aquatic ecosystems, with a focus on Africa.

The aquatic environment represents the final repository for many human-generated pollutants associated with anthropogenic activities. The quality of natural freshwater systems is easily disrupted by the introduction of pollutants from urban, industrial and agricultural processes. To assess the extent of chemical perturbation and associated environmental degradation, physico-chemical parameters have been monitored in conjunction with biota in numerous biological monitoring protocols. Most studies incorporating organisms into such approaches have focussed on fish and macroinvertebrates. More recently, interest in the ecology of parasites in relation to environmental monitoring has indicated that these organisms are sensitive towards the quality of the macroenvironment. Variable responses towards exposure to pollution have been identified at the population and component community level of a number of parasites. Furthermore, such responses have been found to differ with the type of pollutant and the lifestyle of the parasite. Generally, endoparasite infection levels have been shown to become elevated in relation to poorer water quality conditions, while ectoparasites are more sensitive, and exposure to contaminated environments resulted in a decline in ectoparasite infections. Furthermore, endoparasites have been found to be suitable accumulation indicators for monitoring levels of several trace elements and metals in the environment. The ability of these organisms to accumulate metals has further been observed to be of benefit to the host, resulting in decreased somatic metal levels in infected hosts. These trends have similarly been found for host-parasite models in African freshwater environments, but such analyses are comparatively sparse compared to other countries. Recently, studies on diplozoids from two freshwater systems have indicated that exposure to poorer water quality resulted in decreased infections. In the Vaal River, the poor water quality resulted in the extinction of the parasite from a site below the Vaal River Barrage. Laboratory exposures have further indicated that oncomiracidia of Paradiplozoon ichthyoxanthon are sensitive to exposure to dissolved aluminium. Overall, parasites from African freshwater and marine ecosystems have merit as effect and accumulation indicators; however, more research is required to detail the effects of exposure on sensitive biological processes within these organisms.

First record of a spiral form of Aulacoseira, A. ambigua f. japonica (F.Meister) Tuji & D.M.Williams, in South African fresh waters

Water quality and algal populations in the Vaal River Barrage Reservoir have been monitored extensively for many decades, because of its importance as a water source for the most densely populated area in South Africa. Although Aulacoseira granulata (Ehrenberg) Simonsen is frequently found and at it times dominates algal assemblages in the Barrage, Aulacoseira ambigua (F.Meister) Tuji & D.M.Williams has never before been recorded at this locality. During a countrywide proficiency-testing scheme for algae counting, coordinated by Rand Water, spiral-shaped diatom colonies with distinctly curved cells were detected during May 2015. Upon investigation, it was found that the spiral colonies were Aulacoseira ambigua f. japonica, its presence in the fresh waters of South Africa being recorded for the first time. Since their first appearance during May 2015, colonies of Aulacoseira ambigua f. japonica have been constantly present in the surface waters of the Barrage. Their presence at this site can be linked to increasing eutrophication in the Vaal River, because the spiral form is known to prefer eutrophic conditions. Centric diatoms rarely form spiral colonies and there is some confusion in the literature as to the identity of this particular form, therefore in this paper we discuss this taxon, its nomenclature and ecological significance.

Long-term changes in the algal composition of the Vaal River, South Africa – did the Lesotho Highlands Water Project play a role?

The Vaal River has become so nutrient-enriched that algal blooms pose problems. A unique opportunity arose to determine if there were changes in the chemistry en algal composition of the Vaal River after oligomesotrophic Katse Dam (Lesotho) water was imported to augment supplies in the light of growing water demands in the Vaal River catchment area. Algal concentration and composition in the Vaal River during three periods (between 1992 and 1994, 1998 and 2000, as well as 2004 and 2006) were compared to those in the Katse Dam (1998–2006). Some algal species, initially absent from the Vaal River, appeared in the river during and after transfer. Mixed algal assemblages found in the Vaal River before transfer of Katse Dam water gradually changed after transfer to assemblages mainly composed of cyanobacteria. The total algal concentration in the Vaal River Barrage doubled from the period between 1992 and 1994 to that between 2004 and 2006, indicating that the transfer of clear, oligomesotrophic Katse Dam water did not dilute the eutrophic Vaal River water sufficiently in order to reduce algal concentrations. Results showed that continuous downstream pollution and eutrophication of the Vaal River system eliminated the diluting effect of Katse imports. This resulted in changes in algal composition and concentration in the Vaal, characteristic of those associated with increasing eutrophication.

Notes on the occurrence of <i>Trypanosoma</i> sp. (Kinetoplastida: Trypanosomatidae) in freshwater fishes from South Africa

A total of 257 fishes from four families, Clariidae, Cichlidae, Cyprinidae and Schilbeidae were collected from three localities: the Sand River Dam, Swaziland; the Nylsvlei Nature Reserve, South Africa and the Vaal Dam and Vaal River Barrage, South Africa. Only fishes (n= 154) from Clariidae and Cichlidae were found to be infected with trypanosomes. A total of 221 Clarias gariepinus (Burchell 1822) were collected from the Vaal Dam and Vaal Barrage area, South Africa. Of these, 74%(89/121) were infected with trypanosomes from the Vaal Dam and 63%(63/100) from the Vaal River Barrage, with no seasonal infection pattern. A prevalence of 25%(1/4) was found in C. gariepinus from the Sand River Dam, Swaziland, and a 50% (1/2) prevalence was found in Tilapia sparrmanii from the Nylsvlei Nature Reserve, South Africa. Standard measurements conformed closely to the morphometric and morphological descriptions of Trypanosoma mukasai. This article provides new locality records for T. mukasai from the Vaal Dam, Vaal River Barrage and Nylsvlei Nature Reserve (South Africa) and the Sand River Dam (Swaziland). Tilapia sparrmanii collected in the Sand River Dam in Swaziland is also noted as a new host record.

Paradiplozoon ichthyoxanthon n. sp. (Monogenea: Diplozoidae) from Labeobarbus aeneus (Cyprinidae) in the Vaal River, South Africa

A new species, Paradiplozoon ichthyoxanthon (Monogenea: Diplozoidae) is described from the gills of Labeobarbus aeneus (Cyprinidae) in the Vaal Dam and Vaal River Barrage in the Vaal River, South Africa. This species is the first in this genus from southern Africa; Paradiplozoon aegtyptense and Paradiplozoon ghanense have been described from northern Africa. The new species differs from all other Paradiplozoon species on the basis of the combination of morphological characteristics, namely disk-like haptor, eggs without filaments, clamp and central hook morphology and size of specimens. The species description is accompanied by a description of the reproductive organs. The internal transcribed spacer of the ribosomal gene (ITS2) was studied and the South African individuals formed a distinct clade, supporting the establishment of a new species.

Uptake of selected metals in tissues and organs of <i>Clarias gariepinus</i> (sharptooth catfish) from the Vaal River System – Chromium, copper, iron, manganese and zinc

This paper discusses concentrations of 5 essential trace metals (chromium, copper, iron, manganese and zinc) in water, sediment and various fish (C. gariepinus) tissues. With the exception of high Zn concentrations in skin, the highest essential element metal concentrations were generally recorded in liver and gill arch tissues, followed by gill filaments and lastly skin and muscle. This general trend is in agreement with trends reported by other workers. Fe concentrations were found to be significantly higher at the Vaal Dam more often than at the Vaal Barrage. In comparison, Mn concentrations were higher at the Vaal River Barrage more often than at the Vaal Dam. No clear trends emerged with regard to differences between localities for the other metals, or between surveys/seasons for all essential trace metals examined. The likely reason for the lack of distinct trends is the amount of variability observed in tissue metal concentrations within localities and seasons in this study. Such variability is also reflected in current literature and accentuates the importance of both abiotic (e.g. physical water quality variables) and biotic (e.g. host physiological status, general biology and life history traits) factors influencing the concentrations and bioavailability of trace metals.

An assessment of the influence of multiple stressors on the Vaal River, South Africa

The Vaal River is situated in the mining and industrial heartland of South Africa. It is regarded as a “work horse” river in South Africa and as a consequence it receives treated waste water from the largest metropolitain area in South Africa. It is only with the more frequent occurance of fish kills in the Vaal Barrage area during the past few years that public attention has been drawn towards the decreasing water quality and subsequent deterioration in the aquatic health of the Vaal River system. The aim of this study was to apply a multi-metric approach to assessing the risk of the multiple stressors to fish populations of the Vaal River system. A relative risk assessment approach was applied to divide the Vaal River Barrage into four risk regions. Field sampling was undertaken to validate the predicted risks in each region. The sampling included abiotic (i.e. water and sediment quality) and biotic (fish components) assessment. General water quality parameters (pH, conductivity, dissolved oxygen) together with nutrient, bacteriological and metal concentrations were measured in the four regions. Sediment quality was determined through physical (particle size distribution) and chemical (metal and organic pollutant) analyses. The fish assessment was undertaken at different levels of biological organisation ranging from biomarkers at subcellular levels (cytochrome P450-EROD, metallothionein, acetycholine esterase, antioxidant enzymes, cellular energy), tissue (histopathology), whole organism (fish health index), population and community level. These biological responses were related to environmental exposure through bioaccumulation analyses of metals and organic pollutants in fish tissues. Multivariate statistical analyses were applied to integrate the environmental exposure and effects. The results indicated that those regions that were predicted to be at greatest risk to exposure of multiple stressors did indeed display the greatest disturbance in fish community structures. This was related to decreased fish health as demonstrated by increased oxidative stress due to exposure to metals such as copper and nickel as well as organic pollutants such as PCBs, HCHs and bromated flame retardants. This study clearly demonstrates the importance of the inclusion of higher tier assessment endpoints to elucidate the effects of multiple stressors in aquatic ecosystems. The study further allowed for the identification of specific effect endpoints that need to be included in future monitoring programmes such as viral immunoassays.

Bioaccumulation of non-essential trace metals in tissues and organs of <i>Clarias gariepinus</i> (sharptooth catfish) from the Vaal River system – strontium, aluminium, lead and nickel

This is the first paper reporting on results obtained in a metal bioaccumulation study in the Vaal River system. It discusses concentrations of four non-essential elements (strontium, aluminium, lead and nickel) in water, sediment and various fishtissues. A second paper will report on concentration levels of the remaining five essential trace metals (chrome, copper, iron, manganese and zinc) studied. While heavy metals did accumulate in C. gariepinus tissues, no clear trends emerged with regard to differences between localities (Vaal Dam and Vaal River Barrage) or surveys. The highest non-essential element metal concentrations were generally recorded in gill (filaments and arches), followed by muscle, liver and lastly skin. This general trend appears to be in agreement with trends observed by other workers and reported in the literature. Variability in tissue metal concentrations in C. gariepinus within locality and seasons observed in this study is also reflected in results from available literature. This accentuates the importance of factors that influence the concentrations and bioavailability of trace metals.Keywords: Heavy metal pollution, bioaccumulation, Clarias gariepinus, Vaal River Barrage, Vaal Dam, strontium, aluminium, lead, nickel

Application of a fish health assessment index and associated parasite index to Clarias gariepinus (Teleostei: Clariidae) in the Vaal River system, South Africa

The aim of this study was to determine if the fish health assessment index (HAI) developed in the USA and associated parasite index (PI), when applied to Clarias gariepinus at two localities in the upper and middle Vaal River system, could distinguish between localities on the grounds of water quality. Elevated HAI values, correlating with poorer chemical and physical water quality, were recorded from the Vaal River Barrage site. Parasite data were congruent with the main PI premise that prevalence and intensity of endoparasite infection would be higher at the more polluted locality, with the converse being recorded for ectoparasites. It was therefore possible to distinguish between localities with different water quality, based on parasites present on the hosts.

Civil society and sanitation hydropolitics: A case study of South Africa’s Vaal River Barrage

The Vaal River Barrage, situated on the south-eastern border of the Gauteng Province, has been part of the hydrological landscape of South Africa’s most populous and economically active region for more than eight decades. After its completion in 1923 the Barrage was compromised by the construction, upstream, of the Vaal Dam (1930–1933). Today the Vaal River Barrage is primarily a storage facility of sewage and industrial waste water. South Africa’s transition to a multi-racial democracy in 1994 saw a number of socio-economic and political transformations that affected the water infrastructure. In the field of sanitation infrastructure in particular, conditions have deteriorated to the extent that the health of people in many parts of the country is being compromised. Using the Vaal River Barrage as a case study, this article outlines the efforts by civil society to make the relevant government sectors aware of this hazardous state of affairs. particular attention is given to save our Vaal environment (SAVE), a non-governmental organisation, at the helm of an active campaign to reduce pollution in the Vaal River Barrage.

The Vaal River Barrage, South Africa’s hardest working water way: an historical contemplation·

South Africa’s Vaal River is the country’s hardest working rivers. It has been instrumental in securing valuable water supplies in the development of the country’s economic hub – the Gauteng Province. Since the mid-twentieth century there have been increasing indications of water pollution threatening the storage facility of the Vaal River Barrage, built by the water utility, Rand Water, at the start of the twentieth century. Currently, as a result of a variety of factors, untreated wastewater is posing a severe environmental threat in the Vaal River Barrage Catchment area. In the article attention is given to the origins of pollution and recent events that had the effect of mobilising grassroots anger in civil society with the state of affairs. The article forms part of a transdisciplinary research project that is currently conducted at North-West University’s Vaal Triangle campus in Vanderbijlpark.

Aspects of the Ecology of Lamproglena Clariae (Copepoda: Lernaeidae) from the Vaal River System, South Africa

Abstract This study refers to the ecology of Lamproglena clariae. Specimens were collected from the Vaal Dam and Vaal River Barrage in the Gauteng Province, South Africa, for a two-year period. Data were analysed statistically. There was a positive correlation between the host's physical dimensions and the size of the parasite. Larger fish had larger parasites than smaller ones. Parasites from both sites preferred the fourth gill and the median part of the gill arch for attachment. There was no significant host gender preference by parasites. A similar seasonal pattern was observed in the prevalence, abundance, and mean intensity at both localities. This study shows that some aspects of the ecology of the parasite are influenced by the host to which it attaches. Its attachment-site preference was also determined by the position of the gill on the gill chamber. The parasite abundance and prevalence were neither dependent on the size of the host nor influenced by the water quality.

The implications of point source phosphorus management to potable water treatment

The Vaal River Barrage reservoir is an important source of raw water for Rand Water which supplies at least 10 million people with drinking water daily. Return effluents from waste water treatment works, industries and informal urban settlements in the catchment has resulted in algal problems in the raw water and treatment process. In order to attempt to reduce the effect of eutrophication of South African inland water quality the Department of Water Affairs implemented in 1985 a 1 mg/l ortho-phosphate standard for waste water treatment works effluents. The amount of phosphate originating from the waste treatment works decreased significantly over the 10 years after the standard was implemented even though 40% of the time the works do not comply to the standard. This has resulted in no significant change in the chlorophyll values at Rand Water Intake No. 1. The algal species composition has changed with blue-greens becoming more dominant which has resulted in a higher incidence of algal related problems. The stabilizing of the chlorophyll values is not only as a result of lower ortho-phosphate levels but also due to residence times, turbidity and conductivity. To further reduce the algal concentrations at Rand Water Intake No. 1 the 1 mg/l ortho-phosphate standard will have to be enforced, the standard possibly reduced and diffuse sources managed on a catchment basis.

The implications of point source phosphorus management to potable water treatment

The Vaal River Barrage reservoir is an important source of raw water for Rand Water which supplies at least 10 million people with drinking water daily. Return effluents from waste water treatment works, industries and informal urban settlements in the catchment has resulted in algal problems in the raw water and treatment process. In order to attempt to reduce the effect of eutrophication of South African inland water quality the Department of Water Affairs implemented in 1985 a 1 mg/l ortho-phosphate standard for waste water treatment works effluents. The amount of phosphate originating from the waste treatment works decreased significantly over the 10 years after the standard was implemented even though 40% of the time the works do not comply to the standard. This has resulted in no significant change in the chlorophyll values at Rand Water Intake No. 1. The algal species composition has changed with blue-greens becoming more dominant which has resulted in a higher incidence of algal related problems. The stabilizing of the chlorophyll values is not only as a result of lower ortho-phosphate levels but also due to residence times, turbidity and conductivity. To further reduce the algal concentrations at Rand Water Intake No. 1 the 1 mg/l ortho-phosphate standard will have to be enforced, the standard possibly reduced and diffuse sources managed on a catchment basis.

A FLOOD PLAIN DEVELOPMENT POLICY FOR THE VAAL BARRAGE.

Keywords WITWATERSRAND UNIVERSITY, RAND WATER WATER, FLOOD PLAINS, BARRAGES, DEVELOPMENT, POLICIES, RIVERS, CATCHMENTS, CONTROL, FLOODS, RISKS, ANALYSIS, URBANISATION, ROUTING, DAMS, UPSTREAM, LEVELS, BANKS, HYDROLOGY, ESTIMATION, WATERWAYS, HAZARDS, METHODS, CALCULATIONS, ESTIMATES VAAL RIVER, VAAL BARRAGE, VAAL DAM SOUTH AFRICA, AFRICA... Show All

Point Source Phosphorus Management, a Five Year Southern African Experience

The Vaal River Barrage reservoir is an important source of raw water for the Rand Water Board. Activities in the catchment of this reservoir resulted in enrichment of this water with concomitant eutrophication related water quality problems being experienced by the Rand Water Board. In order to limit enrichment of raw water a standard of 1 mg PO4−P/ℓ for waste water treatment plant effluent was imposed and the effects of this standard on the algal concentrations at the No. 1 intake in the Vaal River Barrage reservoir was investigated. Although only 24 per cent of waste water treatment plants in the catchment of the Vaal River Barrage reservoir complied with the phosphate standard for more than 75 per cent of the time, the amount of phosphate emanating from the treatment plants in general decreased significantly. This resulted in a lower orthophosphate concentration at the Board's No. 1 intake. The associated lower chlorophyll concentrations at No. 1 intake was, however, not only due to the lower orthophosphate concentrations, but also to the residence time and chemical/physical factors. To limit the algal concentrations at No. 1 intake, the 1 mg/ℓ orthophosphate standard will have to be enforced strictly and diffuse source management will have to be implemented.