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This study used a survey questionnaire to investigate the state and determinants of household food security in South Africa and Botswana. In South Africa, 1557 households in two District Municipalities within Eastern Cape Province participated in the study. In Botswana, data was collected from 506 in Southern Kanye, southeast District, and Gaborone households. The paper employed Household Food Insecurity Access Scale and Prevalence to investigate the state food security across the sample population. The Household Food Insecurity Access Prevalence was used to determine the characteristics of and changes in household food insecurity of the sample households. The linear and ordinal regression analyses were carried out to outline determinants of food insecurity in the region. Findings emanating from the current study show a high prevalence of food insecurity in both countries. Meanwhile, geographical location, household size, and socio-economic infrastructure emerged as common determinants of food security for Botswana and South Africa. The paper recommends state-mediated intervention to improve access to basic socio-economic infrastructure and address unemployment rates in both countries as key areas to improve food security status.

Heavy metal pollution is an increasing threat to the marine environment and is a major health concern. Both marine limpets and algae have been employed as biomonitors elsewhere in the world, but there are few or no data for these taxa along the South African coast. We investigated heavy metal concentrations in the tissues of selected limpet and algae species sampled at four sites on the southeast coast of South Africa (Silaka, Hluleka, Mthatha and Mbhashe), and determined whether there was any relationship between heavy metal concentrations in the limpets and their algae food sources as evidenced by the trophic transfer factor (TTF). Samples were collected in July 2019 and the tissues were digested following normal protocols. Heavy metals were detected using inductively coupled plasma optical emission spectrometry (ICP-OES). Significant differences in metal concentrations were observed among the algae species. The soft tissues of limpets from Silaka had the highest heavy metal concentrations, and samples from Mthatha had the lowest, with only mercury (Hg) occurring in high concentrations. Metal concentrations in soft tissues were generally 10-times higher than in shell tissues and differed between lower- and upper-shore species. Cadmium (Cd) biomagnified (TTF > 1) in all limpet species at all sites. Cd, arsenic (As), lead (Pb) and Hg measured in our study were above the maximum limits set by the South African Department of Health. This study suggests that the use of limpet and algae species as bioindicators is feasible since they are widely distributed and can accumulate a wide range of heavy metals.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XLIV-4/W3-2020, 2020 5th International Conference on Smart City Applications, 7–8 October 2020, Virtual Safranbolu, Turkey (online) Water shortages are a chronic and severe problem in South Africa. Allocation of this limited water resources, environmental quality, and policies for sustainable water use are issues of increasing concern that require accurate and timely information to evolve strategies for dynamic natural resources management. Specifically, this paper is aimed to assist the planning, restoring and to rationally allocate the water resources in any river basin in resolving the current water stresses in many parts of South Africa, by using integrated knowledge from simulation and integrated river basin management approach. The developed system dynamic (SD) allocation system was used to investigates the extent to which the framework is ‘sustainable’ in the medium and long terms in evaluating existing and future water allocation among conflicting users at Mkomazi River Basin (MRB), KwaZulu-Natal Province, South Africa The invented SD framework confirms agricultural water use as the highest demand when compared with other users. The optimal sustainability performance index (0.25) of the system at 70% dependable flow shows an integrated scenario that combines rainfall variation with improved irrigation water use efficiency as a suitable framework plan. The study uses integrated knowledge from simulation and integrated river basin management approach as a feasible method to assist the planning, restoring and to rationally allocate the water resources in any river basin with similar attributes to the study area in resolving the current water stresses in many parts of the country. Water resources managers would find these tools beneficial in understanding the complex nature of water resources allocation and in determining priorities area which required prompt attention and intervention

This study investigates potential changes to hydropower generation using diverse efficiency indexes (EIs) under climate change scenarios of different water year types including “dry” defined as the lower 20 percentile, “normal” as the middle 60 percentile, and “wet” as the upper 20 percentile from the low flow frequency analysis (LFFA) in retrofitting the hydropower description relative to the current conditions. For this study, the multiple linear regression model was fitted to the annual minimum 1 of 7-day average flows with recurrence intervals of 1, 3, 7, 15, or 30 years which were computed using the log-Pearson Type III mathematical technique (LPIII). The climatic impacts’ scenarios results of different water year types’ likelihoods of exceedance give the total annual hydropower as 0.631 MW, 0.550 MW, and 0.392 MW respectively for the lower 20 percentile while the equivalent reservoir inflows result shows an upwards trend in total amounts of runoff, though the patterns of possible changes are both temporally and spatially complex. It is thus important to understand stream and catchment behaviors during the period of limited flow in both natural and under various anthropogenic events. This will provide useful information for long-term river basin management under climate-change conditions which is also necessary for supporting aquatic lives.

Freshwater inflow has a strong impact on the biological, chemical and physical characteristics of estuaries, which in turn affect the distribution and abundance of estuarine organisms. Increased cl...

We tested the effects of marine reserve status on the reproductive biology and recruitment rates of two commonly exploited (Helcion concolor, Scutellastra longicosta) and two rarely exploited (Cellana capensis, Scutellastra granularis) limpet species using two reserve and two non-reserve sites on the south coast of South Africa. Because densities of commonly exploited species are lower outside reserves, we hypothesised that limpets outside reserves will: (i) mature earlier; and (ii) show higher individual reproductive output. Rarely exploited species should show no such effects. For recruitment, we hypothesised that if recruits are attracted to adults or survive better where there are more adults, then commonly exploited (but not rarely exploited) species should show higher recruitment inside reserves. Analyses of gonadosomatic indices produced significant Month × Reserve interactions for all species (ANCOVA, p < 0.05), indicating inconsistent reserve effects even for exploited species, although months wi...

The rising prevalence of the failure of fast-growing cities’ waste authorities to account for solid waste service function and provide effective solid waste systems poses serious environmental hazards and health risks. Household solid waste mismanagement in Mthatha, a fast-growing city in South Africa with a rapid population increase, is emerging as a major environmental hazard. An effective solid waste audit system could reduce the extent of this problem. This study aimed at categorising and quantifying household solid waste generation and determining the drivers of waste generation and mismanagement that have the potential to increase risk and/or vulnerability to household solid waste-related environmental hazards. Stratified random sampling was used to select 248 sample households and to categorise them according to upgraded high-density informal residential settlements (64), high-density formal residential settlements (62), middle-density residential settlements (61) and low-density residential settlements (61). The results revealed that the waste generation rate increased one moves from informal settlements (1.84 bags of waste per household per week) to low-density, low socio-economic statuses (2.26 bags), middle-density settlements (2.39 bags) and low-density residential settlements (2.84 bags). Food waste was the most commonly generated type of waste for more than 50% of the respondents. Approximately 89% of the most common types of waste reported across all settlements had the potential to be recycled, reused or composted. Only four factors emerged as significant determinants (p < 0.05) of the volume of solid waste generated per household per week: household socio-economic status, household size, knowledge of waste management and household participation in waste separation. Results on drivers of household solid waste generation and variations across residential settlements could be utilised when designing growing cities’ waste management plans, with the objective of reducing the volume of solid waste sent to landfill sites, illegal dumping and open burning of waste, thus reducing the associated negative impacts that mismanaged waste poses to the environment. Enforcing waste separation at the household level could promote reuse and recycling, which in turn would reduce waste volumes. Keywords household waste generation; socio-economic drivers; residential density; refuse removal; waste types.

Identification of fungal species based on morphological characteristics is tedious, complex, prone to errors, and thus cannot be completely relied upon. In this study, internal transcribed spacers (ITS 1 and 4)—polymerase chain reaction was employed to amplify DNA of 19 mushroom isolates collected at Environmental Pollution Science and Technology farm, Ilesa, Southwest Nigeria. The PCR amplification of ITS1 and 4 of the mushrooms isolates yielded approximately 850 bp. Amplicons obtained were sequenced and identified using BLASTn in the NCBI. The BLASTn results revealed that Termitomyces aurantiacus (3), Tricholoma matsutake (8), Tricholoma robustum (2), P. ostreatus (4), Schizophyllum commune (1) and Pleurotus pulmonarius (1) were fully represented. Only Tricholoma matsutake (KT273371), Pleurotus pulmonarius (KY962469) and Tricholoma matsutake (AF438605) had 100% similarity with reference strain. However, the phylogenetic analysis of the isolates showed low genetic relatedness with reference strains. This study revealed the novelty of the mushroom strains and thus advocating the need for strict conservation measures and further investigations on their potential benefits to mankind.

Dry spells and climatic hazards are responsible for maize output decline, sometimes to levels below potential yield levels. There is a pressing need to reduce the gap between actual and potential maize yield/ha, especially among farmers in semi-arid regions. This present study examines the potential role of supplemental irrigation and its differential impact on maize yield in the Eastern Cape Province of South Africa. In this study, maize yield data were generated from information recorded over a period of 20 years by farmers in Ntabankulu through cross-sectional interviews with 124 randomly-selected farming households. Maize yields for interviewed farmers were analysed for each of the experienced climatic hazards, for yield decline per ha and preferable adaptation strategies. Maize yield analyses show a maximum ceiling/attainable yield of 0.234 t/ha and average farm yield of 0.146 t/ha. Floods or hailstorms cause 75% decline in maize yield/ha and there was no significant difference between farmers practising irrigation and those practising dryland farming ( P > 0.05). Low/no rains throughout the season; delay or low onset of rainfall and a rain-break for a week or more in a season results in 75%; 54% and 50.5% decline in maize yield/ha, respectively. On a scale of 1 to 10, farmers highly rank practicing supplementary irrigation (8.4) and change of planting date (7.8) as important adaptation strategies. Rescheduling planting date from the traditional planting times to earlier or later planting dates, assisted by use of weather reports and forecasting, to some extent curbs the impact of delays or slow onset of rainfall on yield. Supplemental irrigation is instrumental in reducing the impact of mid-season drought (rains break for a week) and light rainfall throughout the season. Analyses of actual yields and yield decline against each of the experienced climatic hazards provided insight into management possibilities to stabilize maize output. Keywords: agronomic practices, climatic hazards, supplemental irrigation, semi-arid areas

Source-sink theory has contributed to our understanding of the function of protected areas, particularly due to their role as population sources. Marine reserves are a preferred management tool for the conservation of natural populations, creating areas of good quality habitat and thus improving population connectivity by enhancing larval supply and recruitment among shores. Despite recent advances in the study of protected areas in the context of the source-sink theory, rigorous and empirical testing of marine reserves as metapopulation sources for the adjacent areas remain largely unexplored. We investigated the role of marine reserves as population sources, whether there was spill-over beyond the reserve boundaries and if so, whether spill-over was directional. We measured percentage cover and recruitment of mussels (Perna perna) at two reserves and two comparably sized exploited control areas on the south-east coast of South Africa where unprotected populations are severely affected by artisanal exploitation. Adult abundances were enhanced within reserves, but decreased towards their edges. We predicted that recruitment would mirror adult abundances and show directionality, with northern shores having greater recruitment following the prevalent northward flow of near-shore currents. There were, however, no correlations between adult abundances and recruitment for any months or shores, and no clear spatial patterns in recruitment (i.e. similar patterns occurred at reserves and controls). The results emphasise that, while reserves may act as important refuges by protecting adult abundances, their influence on promoting recovery of near-by exploited shores through larval spill-over may be overestimated.

The effects of marine reserves on the growth and mortality rates of 2 commonly exploited (Helcion concolor and Scutellastra longicosta) and 2 rarely exploited (Cellana capensis and Scutellastra granularis) limpets were investigated at 2 reserve and 2 non-reserve sites in South Africa. Two hypotheses were tested: (1) growth of commonly exploited species would be reduced in reserves due to higher densities and stronger intraspecific competition, with no effect for rarely exploited species; (2) commonly exploited species would show higher mortality rates outside than inside reserves, with no effect for rarely exploited species. Both the exploited H. con- color and C. capensis (sometimes mistaken for H. concolor by harvesters) exhibited faster growth at non-reserve sites where their densities were generally lower. No effect of reserve status was detected for the growth rates of S. granularis (rarely exploited) or S. longicosta (commonly exploited). S. longicosta showed no reserve effect on growth because it is territorial, and density has no effect on territory size. Reserve effects were only observed for the survival probability of S. longicosta, the most commonly exploited species, and the probability of capture (but not sur- vival) of the 2 rarely exploited species. The results indicate that the effects of reserves on growth and mortality are species-specific and are difficult to generalize even within the categories of commonly and rarely exploited limpets.

Populations of organisms that create habitat can often be fragmented throughout landscapes by anthropogenic disturbances such as harvesting and loss or change to the identity of such bioengineers may lead to large changes in biodiversity. Using the fauna associated with a bioengineer, the intertidal mussel Perna perna, we tested hypotheses about the relative importance of larval export from protected populations in marine reserves. Harvesting led to the replacement of P. perna and the domination of shores outside reserves by turf-forming coralline algae, mostly Corallina spp. We determined whether the diverse fauna recruiting onto artificial units of habitat placed within mussel beds differed between reserves and non-reserve areas or whether shores outside reserves, and open to harvesting, received recruits through larval export from reserves. Furthermore, we determined whether this was affected by the distance away from reserves and whether colonisation was achieved by movement of adults from surrounding biogenic habitats or via the plankton. Overall, we found no effect of increasing distance away from a reserve on the cover of adult mussels or associated fauna. We found strong effects of the presence of marine reserves on abundances of molluscs and polychaetes but not crustaceans. There were greater densities of molluscs in sites with a reserve (i.e. inside reserves, and up to 5 km outside reserve boundaries), but more polychaetes in exploited sites. For molluscs, this pattern was driven by gastropods rather than bivalves. Furthermore, although reserves had greater cover of adult mussels than non-reserve areas, recruitment of mussels was not greater inside or near to reserves. Our study illustrates the effectiveness of these reserves in protecting stocks of adult mussels, and although there was no evidence that reserves provided export of the larvae of mussels (the target species), they did provide larval export of non-targeted associated species. By protecting a harvested bioengineer and through export of the larvae of its associated fauna, these reserves fulfil some, but not all the conservation aims of a marine protected area.

The Kariega Estuary in South Africa, is an example of a freshwater-deprived estuary. Large-scale water abstraction and droughts have resulted in this estuary either being uniformly marine or hypersaline. A major episodic flood event in October 2012, the largest ever recorded in this system, provided us with an opportunity to investigate the prolonged effect of an episodic flood on the demersal fish assemblage of a freshwater-deprived estuary. A beam trawl net was used for sampling the fish assemblages from December 2013 to November 2014. The flood event before the sampling period ‘reset’ the system, such that there was a longitudinal salinity gradient from the head to the mouth, which resulted in ‘normal’ estuarine conditions, typical of most estuaries. There was an increase in the abundance of benthopelagic marine migrant species, particularly early juveniles of important fishery species, in the middle and upper reaches during the present study relative to previous studies conducted in this freshwater-deprived system. This suggests increased recruitment of these species into their estuarine nursery habitat. The present study highlights the importance of understanding the effect of freshwater inflow on the demersal estuarine fish assemblage and the nursery role of this and other estuarine systems and their management.

Increasing urbanization trends have seen natural ecosystems increasingly being replaced by urban development. Rapid rate of urban growth is causing social and environmental strains. The magnitude of the problem is partially reflected by the higher amount of solid waste generated. Consequently, common features of urban areas are stinking heaps of uncollected waste, waste disposed haphazardly by roadsides, open spaces, valleys, drains and rivers, non-compliance by waste disposal facilities. Spatial planning and environmental protection through rapidly growing population had influenced changes in ways at which waste was managed. The aim of this study was to identify the impact of waste management to the environment and communities in OR Tambo District Municipality. To achieve this, field observations and visits to local municipalities were conducted, water quality parameters (pH, Temperature, and Dissolved Oxygen) were measured on site using the Eutech Cyberscan series 600 portable water quality meter and water samples were taken to test for the concentration of nitrates and phosphates. A two-way analysis of variance (ANOVA) was used for statistical analyses. Questionnaire surveys and interviews were conducted in schools and clinics adjacent to landfill sites to investigate community impacts and analysed using SPSS statistics 21. There were significant differences in dissolved oxygen and pH among sites in municipalities. There were challenges identified in communities with negative implications ranging from socially, environmentally and on health. These results highlight the need for waste minimisation, community-based waste management, environmental education, law enforcement and safe disposal in local municipalities.

Background: In South African traditional medicine, some are plants known to combat pediatric diseases and are commonly used by traditionalhealers. The aim was to evaluate cytotoxicity effects of plants.Materials and methods: The ground plant material was exhaustively extracted using methanol, acetone and water separately for 72 hrs. Theseorganic solvents were removed from filtrates using a rotavapour. Stock solutions were prepared at 40 mg/ml Dimethyl sulfoxide (DMSO) and testsolutions were transferred into vials and 10 brine shrimps introduced in each. The number of dead shrimps was counted to ascertain toxicity. Ten A. salina nauplii (larva) were transferred into each sample vial and filtered brine solution was added to make 5 ml. The nauplii were counted macroscopically in the stem of the pipette against a lighted background. A drop of dry yeast suspension was added as food to each vial. Probit analysis was used to determine the concentration at which lethality to brine shrimp represents 50 % (LC50).Results: All the tested extracts showed that the concentration is directly proportional to death of brine shrimps. Fifty percent lethality (LC50) of thetested crude extract ranged between 4.1 and 4.6 µg/ml with methanol extract of B. abyssinica being the lowest and T. acutiloba the highest.Conclusion: This study revealed that 100% of plant crude extracts screened for activity against Artemisia salina larvae showed strong cytotoxicitybelow 10 µg/ml and plant species with LC50 values < 1000 µg/ml may not make good paediatric remedies due to their inherent toxicity.Key words: Medicinal plants, traditional pediatrics, cytotoxicity