Search

Biological monitoring tools are largely lacking for many countries, resulting in adoption of tools developed from other countries/regions, but in many instances, their applicability to the new system has not been explicitly evaluated. The objective of the study was to test the applicability of the South African Scoring Systems Version 5 (SASS5) to urban streams in Zimbabwe. The study evaluated the relationship between water quality variables and SASS5 indices/metrics [(SASS and average score per taxon (ASPT)] and found high degree of concordance between water chemistry parameters and SASS5 metrics, indicating that both SASS and ASPT scores are sensitive to detect environmental changes. This result can be attributed to occurrence of ubiquitous macroinvertebrate taxa sharing similar environmental tolerances with those recorded for South African systems. The applicability of SASS5 metrics need to be tested across different geographical and climatic regions in the country (taking into consideration seasonal variations that are important drivers of benthic faunal assemblages in lotic systems) and disparities among the regions compared for the adoption of the index in the entire country. The SASS5 metrics can also be further strengthened by (a) taking into account the relative abundance of taxa and (b) also improving on its ability to reflect other forms of perturbations besides eutrophication and organic pollution such heavy metal pollution. [ABSTRACT FROM AUTHOR]

The focus of this study was to determine whether coastal wetlands in lowland settings could be dependent on groundwater from the deep circulating confined Table Mountain Group (TMG) aquifer. Groundwater interactions with wetlands are normally perceived to be limited to primary aquifers. A comparative study was done between two endorheic coastal wetlands in the southern Cape. Earlier reports stated that these groundwater dependent wetlands were fed by discharges from the fixed dunes surrounding them. On the basis of a three-dimensional electrical conductivity (EC) interpolation for Groenvlei, a hydrological link between the TMG aquifer and Groenvlei and Van Kervelsvlei was investigated by measuring water level and quality of groundwater and surface water. Water quality parameters used were EC, pH, Na+, Fe2+ and Cl−. The results from this, and an accompanying study, on the basis of water quality and plant nutrient cycling assessments, indicated direct groundwater discharges from the TMG to at least Van Kervelsvlei, with Groenvlei receiving secondary discharges from the TMG via Van Kervelslvlei. These findings significantly affect the current knowledge on which water balance models are based for the determination of groundwater availability for the area. [ABSTRACT FROM AUTHOR]

The inclusion of diatoms into the current suite of biomonitoring tools in use in South Africa, as well as the use of European and other diatom indices in South Africa, and in particular the Crocodile and West Marico water management area, is discussed. The indices, when compared to chemical analyses, proved useful in providing an indication of the quality of the investigated waters. Several widely distributed diatom species were shown to have similar ecological tolerances in South Africa when compared to Europe. Although most of the diatoms encountered in the study were cosmopolitan, several possibly endemic species were recorded. The occurrence of endemic species, not included in existing diatom indices may lead to miscalculations of diatom indices. It is concluded that although diatom indices developed in Europe and elsewhere are useful at the present to indicate water quality, a diatom index unique to South Africa including endemic species will have to be formulated. [ABSTRACT FROM AUTHOR]