Gynecology Obstetrics & Reproductive Medicine

Hook-and-line fishing is commonly used in South African inland fisheries; however, very little quantitative information on catch and effort exists, even though it is essential to advise management of the sector. To provide information towards management of South Africa’s largest impoundment, the Gariep Dam, roving creel surveys were conducted to quantify annual fish harvest and to identify changes in fisher catch, effort and harvest data in comparison to historic data. The surveys were also conducted during the Covid-19 pandemic which presented an additional opportunity to describe fishery dynamics during the pandemic. Randomly stratified sampling was conducted from November 2020 to October 2021, in which catch and effort data of hook-and-line fishers were collected. Two fishery user groups were encountered: recreational and subsistence users were present, but the fishery was dominated by subsistence fishers. There was a more skewed dominance between these fisher groups than what was found during similar surveys in 2007/2008. Catch per unit effort was similar to previous estimates, at 0.51 kg·fisher-1·h-1 (95% CI:0.47-0.54). There was, however, a significant reduction in fishing effort during the sampling period when compared to historic data, and estimated annual total harvest was only one third of what was previously reported. It was also noted that recreational fishers avoided fishing during the Covid-19 pandemic, whereas the subsistence fishers could not avoid fishing as it is their primary means of livelihood. The results of the study suggested that subsistence fisheries provide valuable livelihood support to communities, and serve as an example on what impacts a crisis such as a global pandemic may have on inland fisheries.

Water scarcity is a global problem exacerbated by the ever-increasing population and climate change, especially in arid and semi-arid regions. Different water resource management strategies, such as rainwater harvesting, have been proposed and implemented worldwide to combat water shortage. Mapping of the optimum sites where these rainwater harvesting structures can be constructed is very important. The main objective of this study was to map and identify, using GIS, optimum sites for the construction of rainwater harvesting structures (farm ponds, check dams and percolation ponds) for agricultural and peri-urban purposes in Eswatini. The optimum sites were identified by overlaying various thematic layers including land use and cover, slope, runoff potential, soil texture and depth and drainage density using ArcGIS 10.8. A general rainwater harvesting suitability map was produced for Eswatini, then potential sites for different rainwater harvesting structures were identified. The results of the study indicated that all three rainwater harvesting structures have suitable sites where they can be constructed. Check dams have potential sites which cover 22.7% of the suitable area in Eswatini, while farm pond and percolation pond sites covers 19.7% and 65%, respectively. Information on existing structures such as dams and earth dams for water storage may need to be gathered to verify the proposed sites of the rainwater harvesting structures. This study was able to identify new sites where structures can be constructed for rainwater harvesting which can improve water availability during dry seasons. Further evaluation may need to be done before implementation of these structures. Moreover, implementing this is subject to a number of other factors, such as the economy, feasibility studies as well as social implications. However, the results of this study will assist policy and decision makers in planning for potential sites for water storage as an adaptation to drought and climate change.

The focus of the paper is to address the temporal discrepancies in long-term rainfall trend results in South Africa, by evaluating a systematic range of observation periods over the century-long analysis period of 1921–2022. Available long-term climate projections show that significant parts of South Africa are expected to experience progressively drier conditions, mainly in the west. To assess long-term rainfall trends over the country, historical trends should be determined – the results of published studies for which are not consistent. Arguably the most significant reason for these inconsistencies is the length of analysis period. This study investigates this effect on the magnitude and statistical significance of historical annual rainfall trends over hydrological years, with the data of 94 homogeneous rainfall districts. Trends of annual rainfall were determined for all periods up to 2022, from the 1921–2022 period up to the last 30 years, i.e. 1993–2022. The annual rainfall trends over the longest analysis period show significantly positive trends over most of the central and western parts and significant drying over extensive parts of mainly the far north-east. However, the most recent period (1993–2022) shows significantly drying trends over extensive parts of the west, south and east. Among the main findings is that the change in trends shows a consistent spatial pattern of significant negative change over most of the south-western half, and mostly significantly positive trends over the north-eastern sector. These results are in large agreement with future rainfall projections, particularly for the western half. Ultimately, the study emphasizes the wide range of long-term trends in South Africa, both spatially and temporally, and the importance of considering a range of historical analysis periods in the detection of long-term rainfall changes. In effect, the eventual results provide increased confidence to predicted future rainfall scenarios.

In the present era, polymeric pipes have emerged as the replacement for metallic alternatives in constructing water distribution networks within cities or homes, due to their notable flexibility and durability. Nevertheless, there have been increased concerns over the safety of consuming water that has come into contact with polymeric materials. This issue arises from the possible leaching of organic contaminants, either due to plastic deterioration or from biofilms that typically develop within polymeric pipes. These biofilms may act as a source of disinfection byproducts during water and/or system disinfection. The objective of the study was to investigate the presence of volatile organic compounds (VOCs) that could migrate from plastic plumbing pipes into tap water. For this purpose, 50 tap water samples from different houses within the Al-Madinah Al-Munawwarah residential area (Saudi Arabia) were collected and analysed for the occurrence of VOCs; trichloromethane (1,1,1-TCA), dichloropropane (1,2-DCP), 1,2,3-trichloropropane (1,2,3-TCP) benzyl chloride (BC) 2-nitropropane (2-NP) 2,4-dichlorophenol (2,4-DCP), 4-ethylphenol (4-EP), benzene and 2-butanone using CG-MS. The most prevalent compounds were benzene, 2-butanone, 1,1,1-TCA, 1,2-DCP, BC, and 1,2,3-TCP. These were identified in 78%, 76%, 68%, 58%, 50%, and 42% of the samples assessed, respectively. The levels of 1,2,3-TCP, benzene, 2,4-DCP and BC exceeded the allowable limit in 43%, 10%, 8% and 6% of the samples, respectively. The remaining VOCs were within the WHO standards. The analysis of water source samples revealed the presence of BC, 1,2-DCP, and 4-EP in 40%, 40%, and 30% of samples, respectively, with no other VOCs detected. This suggests that these contaminants primarily originate from polymeric pipes used in household plumbing systems.

In this novel study, the efficacy of metakaolinite for the treatment of acid mine drainage (AMD) was evaluated. The optimized parameters included the feedstock dosage and contact time. Experimental results were further explored using inductively coupled plasma–mass spectrometry (ICP–MS), ICP–OES (inductively coupled plasma–optical emission spectroscopy), Fourier transform infrared spectroscopy (FTIR), high-resolution–focused ion beam/scanning electron microscopy (HR–FIB/SEM), energy-dispersive x-ray spectroscopy (EDS), x-ray fluorescence (XRF) and x-ray diffraction (XRD). Optimum conditions were observed to be 45 min of mixing time, ≥10 gꞏL−1 of feedstock dosage, i.e., metakaolinite, and ambient temperature and pH. The metal content (Fe, Mn, Cr, Cu, Ni, Pb, Al, and Zn) embedded in AMD matrices were partially removed whilst the level of sulphate was significantly reduced. Chemical species removal efficacies were observed to occur in the following sequence; Cr ≥ Zn ≥ Cu ≥ Pb ≥ Mn ≥ Ni ≥ sulphate ≥ Mg ≥ Fe, with the following removal percentages: 100, 91.7, 74.6, 65, 38.8, 37.5, 32.3, 13.8, and 8.3%, respectively. Thus metakaolinite proved to be partially effective in the treatment of AMD emanating from coal-mining processes. Furthermore, to enhance the performance of this technology, a polishing technique needs to be coupled or integrated to further remove residual inorganic contaminants, as well as other forms of modification such as the addition of alkaline agents to synthesize the nanocomposite and increase its alkalinizing capabilities. 

The global Covid-19 pandemic resulted in an economic downturn that influenced behavioural and participation patterns of fishing sectors around the world. Monitoring changes in fisheries is essential for understanding their human dimension and informing decision-making for development, conservation and management of fish resources. This study documented and described fishery patterns and participation during the Covid-19 pandemic through roving creel surveys. In addition, due to historic surveys of the recreational and subsistence fishery, it was possible to compare the current patterns to previous results and to show the potential Covid-19 related impacts. Subsistence fishing dominated the fishery, with 94% of 431 regular fishers utilising the resources for home consumption or sale. Compared to historic surveys, a marked decline in estimated recreational fishing was observed, but no significant change was identified in participation patterns of subsistence fishers. This downturn in recreational fishing affected the socio-demographic characteristics of the fishery, where changes in ethnic participation were noted; there was also an increase in the number of unemployed fishers during the pandemic. Utilisation of the fish resources was dominated by subsistence users and 97% of fish caught was for self-consumption or sale. This underlines the importance of fish for subsistence users, who rely on the resource for food or income and could not avoid fishing during the pandemic, as they had no alternative. This study highlights the importance of socio-demographic and participation data on fisheries, to provide scientific advice to policymakers on ideal responses to events such as a pandemic. This evidence of temporal changes in hook-and-line fisheries provides inland fishery authorities the opportunity to develop mitigation measures with greater resilience to cope with future global crises. Lastly, the study emphasises the importance of access to fisheries, especially during times of high regional economic and societal stress.

Knowledge of the dynamics of groundwater storage is essential in understanding its driving processes and for informed decision-making. This requires data with adequate precision, which can be obtained from in-situ observations and remote sensing products. While field-based methods are expensive to conduct in low-income countries, satellite products are relatively cheap and provide near real-time data to monitor groundwater resources. This study analyses the seasonal dynamics of groundwater storage anomalies in Zimbabwe. The study utilised the Gravity Recovery and Climate Experiment (GRACE) satellite groundwater monthly point data spanning January 2011 to July 2017. Ordinary kriging was performed to show the spatial variations of groundwater anomaly levels for individual months. Maps for the dry season from April to October were merged together as well as for the wet season from November to March. The final raster maps showed long-term average groundwater level anomalies for each season. Findings show significant variations in groundwater storage level anomalies within and between seasons. The general pattern is that groundwater storage levels increased from the south to north of Zimbabwe. During the wet and dry seasons of 2015, almost 75% of the country had an increase in groundwater storage. This rapid approach using satellite-derived groundwater data, in comparison to other optical remote sensing techniques, is useful for rapid groundwater assessment and management.

Groundwater is an essential part of food and water security. This critical resource must be managed appropriately and used sustainably. This study aimed to assess groundwater quality, suitability for domestic and irrigation purposes, and factors contributing to the groundwater chemistry, in the Breede Water Management Area (WMA), Western Cape, South Africa. Groundwater samples were collected and analysed for major ions such as K+, Mg2+, Na+, Ca2+, Cl-, HCO3-, NO3-, F-, SO42− and physical variables like pH, electrical conductivity (EC), total dissolved solids (TDS), and temperature. Water quality index (WQI), total hardness (TH), South African Water Quality Guidelines (SAWQG) and World Health Organisation (WHO) drinking water quality guidelines were used to assess suitability for drinking purposes. Permeability index (PI), magnesium hardness (MH), sodium adsorption ratio (SAR), sodium percentage (Na%) and graphical representations such as Wilcox and United States Salinity Laboratory (USSL) diagram were used to assess suitability for irrigation purposes. Multivariate statistical analysis and the Piper diagram were used to determine the geochemical processes influencing the groundwater quality. TH and WQI revealed that, overall, groundwater in Breede WMA is soft and suitable for drinking. The irrigation suitability indices showed that groundwater is suitable for irrigation, with the exception of a few sites that are doubtful. The dominating water type in the area is Na-Cl, followed by mixed Ca-Mg-Cl. Multivariate statistical methods revealed that the groundwater is affected by the dissolution of rock salts, calcite dissolution, cation exchange and agricultural activities.  The overall groundwater in the Breede Water Management Area is suitable for domestic purposes.  Water in the boreholes along the coastal area and Borehole W1 must be treated before domestic and irrigation use. There must be consistent groundwater quality monitoring in Breede to identify changes in groundwater quality.

The Zandvlei Estuary is the only functioning estuary along the False Bay coastline of Cape Town and is therefore of extreme local ecological importance. The most significant problems are eutrophication and siltation caused by the increased total inorganic nitrogen (TIN) and soluble ready phosphorus (SRP) levels due to urban development and the associated increased impervious surface area in the catchment that drains into it. In South Africa, stormwater drainage systems conventionally channel everything they collect into receiving water bodies without significant treatment. Sustainable drainage systems (SuDS) provide an alternative approach to managing stormwater runoff. They are designed to manage both stormwater quality and quantity while potentially improving biodiversity and amenity. This project modelled the potential improvement in the quality of the water entering Zandvlei Estuary resulting from the implementation of selected SuDS control measures in Zandvlei’s Diep River catchment using the software program, PCSWMM. SRP, TIN, total phosphorus (TP) and total suspended solids (TSS) were selected as pollutant indicators. Treatment trains that included a large, constructed wetland at the bottom of the catchment will likely provide the greatest improvements to the water quality entering Zandvlei – potentially reducing SRP, TIN, TP and TSS by approximately 59%, 53%, 53%, and 66%, respectively – as well as potentially reducing the runoff by 48%. 

Saline water resources are more abundant than freshwater. Bringing these resources into sustainable, productive use will offer opportunities to reduce competition for freshwater resources, especially in arid and semi-arid areas where freshwater is scarce. Hence, the primary objective of this study was to elucidate the dynamics of salt ions in saline profiles of various soil types (sandy Clovelly and sandy loam Bainsvlei) under malt barley cultivation across 2 seasons where no leaching between the seasons took place. Results of this lysimeter study investigating increasing irrigation salinity (ECi) set at 1.5, 4.5, 6, 9, and 12 dSꞏm−1 over 2 seasons were used to explore ion dynamics of a saline environment. The lysimeter set-up included a saline constant (1.2 m) groundwater table with its salinity corresponding to ECi. Findings showed that ion concentrations are higher closer to the water source only in the Bainsvlei soil and remain variable in the Clovelly soil. Salt dynamics were more predictable in sandy loam soil than in sandy soil, making management of saline sandy soils far more challenging when leaching is not possible. Therefore, our hypothesis that the absence of leaching between seasons will lead to a differentiated progressive accumulation of salt ions in the soil profile, with variable effects on the soil depending on soil texture, was true. We conclude that the desalinized zone, which we determined to be at a depth of 600 mm, should be used to guide crop selection. Furthermore, in addition to the apparent provision for leaching of saline profiles, fertilization should target restoring ion balances, especially provisioning for calcium deficiencies. Both soils were prone to nutritional disorders, most especially calcium deficiency. Therefore, in addition to provision for leaching saline profiles, fertilization should target calcium provisioning for crop production in arid saline environments.

Recently, the use of nanoparticles as photocatalysts has gained great importance. However, nanoparticles exhibit some drawbacks for this application and there is a need for new particle technologies to mitigate these drawbacks. A novel particle technology called MicNo based on ZnO has been designed and manufactured, which exhibits the advantages and properties of both micron and nano size. Although performance of MicNo-ZnO has been tested in various applications, it has not been tested as a photocatalyst in any photocatalytic degradation process. In this study, novel designed ZnO was used as a catalyst for methylene blue (MB) degradation in the presence of UV irradiation.  The MicNo-ZnO particles were characterized by structural and morphological properties by XRD, BET and SEM analyses. The effects of catalyst amount, pH, temperature and initial concentration on the degradation process were investigated.  In addition, a reusability study was carried out with 4 cycles under optimum conditions. The MicNo-ZnO particles showed excellent photocatalytic activity with a degradation rate of 96% for methylene blue in 180 min. The pseudo-first-order rate constant for the photocatalytic degradation of MB by MicNo-ZnO was as high as 0.0236 min−1, confirming that MicNo-ZnO particles can be effectively utilized as an alternative catalyst material.

Cholera is an acute infectious disease caused by two toxin-producing strains, namely Vibrio cholerae O1, and Vibrio cholerae O139. Its recorded history stretches as far back as 1817, in Bengal, India, yet it continues to be a public health threat to this present day. Although cholera epidemics are now a relatively rare phenomenon in developed countries, frequent epidemics continue to be experienced in sub-Saharan Africa. Africa accounted for 63.33% of the 223 370 cases of and 4 159 deaths from cholera that were reported globally in 2020. Furthermore, of the 342 900 cholera cases and 3 304 cholera deaths reported globally in 2022, 40.28% of the cases and 77.85% of the deaths were in Africa. Inadequate sanitation infrastructure as well as inadequate provision of quality, safe drinking water in South Africa still creates conducive conditions for the transmission of cholera. In addition, climate change is increasingly becoming a risk factor towards the spread of V. cholerae pathogens in inland regions. To make recommendations on how South Africa, and potentially the Southern African region as a whole, can minimise the resurgence of cholera, this review addressed the following questions: Does South Africa have adequate sanitation infrastructure to curb the spread of cholera? Is there enough intentional surveillance of environmental water sources for vibrios as a cholera outbreak predictive tool? What is the impact of climate change on the resurgence of cholera in South Africa? And, what needs to be done to curb the resurgence of cholera in South Africa?

Highest and percentile values determined for daily, hourly and 5-min rainfall data (July 1994 to June 2021) from 64 automatic weather stations across South Africa were used to define extreme hourly and 5-min rainfall intensity. Internationally, 99.9th and 99.99th percentiles are typically considered as thresholds for hourly and sub-hourly extreme rainfall when forecasting for disaster risk reduction assessments. In South Africa (SA), the average of the 99.9th percentile for hourly rainfall values is 29.9 mm/h. This represents a good indicator of extreme hourly rainfall in SA and is a useful threshold for forecasting flash floods. The average highest of the hourly rainfalls for SA, 53.9 mm/h, should be a good indicator of more extreme hourly rainfalls for the country. The average of the 99.99th percentile for 5-min rainfall values is 12.8 mm/5 min, which equates to 2.6 mm/min. Significantly, the 5-min rainfall data is used to establish South African categories based on rainfall intensity and total rainfall, whereby an event can be classified as a cloudburst, downpour or shower. Using the newly established local categories, the severe thunderstorm of 4 April 2000 at Hoedspruit that produced 132.2 mm in 25 min from an intensifying upper air trough system was classified as a cloudburst. Interestingly, the 66.2 mm recorded in 5 min during this event makes it the world record holder for all-time highest 5-min rainfall, passing the previous world 5-min rainfall record of 63.0 mm in 5 min recorded at Porto Bello, Panama, on 29 November 1911. Return periods of expected maximum daily, hourly and 5-min rainfall, based on yearly highest values, were also calculated for South Africa. This study presents expected maximums for 5-min rainfall in return periods of 10, 25, 50 and 100 years, a first for South Africa, which can inform strategies for disaster risk reduction.

Invasive fungal infections pose a serious risk to human health; therefore, it is important to study the dissemination and proliferation of pathogenic fungal species in the environment. This could prove useful in preventing infections in susceptible individuals, such as those who are immune-compromised or suppressed. Pathogenic yeasts belonging to the genera Candida, Cryptococcus and Rhodotorula are commonly found in various water sources that are used for daily activities and are included in the World Health Organization fungal priority pathogens list, further warranting investigation into the possibility that infections may occur through contact with yeast-contaminated water. In addition, the close association between antifungal pollutants and yeast in water may induce acquired antifungal resistance development, further complicating the effective treatment of these infections. Thus, investigating the presence and antifungal susceptibility of yeast found in water and identifying ways to monitor potential fungal pathogens may prove useful in combating invasive fungal infections. This review deals with the occurrence and infection risks posed by pathogenic yeasts in water as well as the possibility of these yeasts acquiring antifungal resistance due to the simultaneous presence of antifungal compounds from medical and agricultural runoff. 

In South Africa, as in other semi-arid countries, sustainable production of high-value crops  requires precise management of limited water resources. We investigated daily and seasonal changes in stem and fruit growth as indicators of water stress in pear (Pyrus communis L.) trees, in the Western Cape Province. Stem and fruit growth data were collected hourly throughout the 2022–2023 growing season on 2 cultivars commonly planted in South Africa –  Packham’s Triumph and Forelle. Soil water content, tree sap flow, and orchard microclimate were also monitored. Fruit maximum daily shrinkage (MDS) was highly sensitive to soil water deficit and more sensitive than stem size changes. However, the patterns of fruit MDS for both cultivars changed as the season progressed. Early in the season (October–December), there was a strong correlation between fruit MDS and soil water deficit (R2 ~ 0.72). The fruit shrunk with increasing soil water deficit as water loss through transpiration exceeded gains through xylem and phloem inflows. In contrast, daytime fruit size swelled from late December until harvest (February/March), likely because of the dominance of phloem inflows and decreased peel transpiration as the fruit matured. Correlation between fruit expansion and soil water deficit was weaker (R2 ~ 0.32) during the later stage even though fruit growth continued until harvest. Stem MDS consistently showed midday shrinkage throughout the season in response to soil water deficit, but with more scatter (R2~ 0.37). Seasonal total transpiration was greater for Forelle (733 mm) than Packham’s Triumph (539 mm) because of the higher leaf area index of the Forelle and the longer growing season. This study suggests that pear fruit growth data can provide accurate estimates of tree water status, but only during the early stages of growth. Towards maturity, fruit size changes respond indirectly to water deficit, possibly through reductions in photosynthesis.