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Soils and the environment: the past 25 years
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.L. Schoeman --- , Republic of South Africa P.W. van Deventer --- , Republic of South AfricaLocal work on selected environmental impacts on soil quality and the role of soils in the attenuation of environmental pollution is reviewed. Examples of negative impacts from mining, industries, urbanization, agriculture and forestry abound. The safe and sustainable use of... -
OBSERVATTVNS ON THE UNDERWATER LIGHT FIELD OF TWO HWERTROPHIC, SOUTH AFRICAN IMPOUNDMENTS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: R.D. Robarts --- , South Africa T. Zohary --- , South Africa F. Ojeda --- , Chile C. C.E. Lovengreen --- , Chile R.D. Walmsley --- ,The spectral composition of the underwater light field was examined in two hypertrophic South African Impoundments (Hartbeespoort and Roodeplaat Dams) under a range of inorganic turbidities and chlorophyll α concentrations. The data indicated that inorganic turbidity and gilvin were dominant... -
OBSERVATIONS ON THE UNDERWATER LIGHT FIELD OF TWO HYPERTROPHIC SOUTH AFRICAN IMPOUNDMENTS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: R.D. Robarts --- National Institute for Water Research, South Africa T. Zohary --- National Institute for Water Research, South Africa F. Ojeda --- Institute of Physics, Chile C. C.E. Lovengreen --- Institute of Physics, Chile R.D. Walmsley --- Foundation for Research and Development,The spectral composition of the underwater light field was examined in two hypertrophic South African impoundments (Hartbeespoort and Roodeplaat Dams) under a range of inorganic turbidities and chlorophyll a concentrations. The data indicated that inorganic turbidity and gilvin were dominant... -
Refined estimates of South African pelagic fish biomass from hydro-acoustic surveys: quantifying the effects of target strength, signal attenuation and receiver saturation
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JC Coetzee D Merkle CL de Moor NM Twatwa M Barange DS ButterworthThe biomass of small pelagic fish species off the coast of South Africa has been monitored since 1984 using hydro-acoustic survey techniques. These time-series of spawner biomass and recruitment estimates form the basis for management of both the South African... -
Revised estimates of abundance of South African sardine and anchovy from acoustic surveys adjusting for echosounder saturation in earlier surveys and attenuation effects for sardine
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: CL de Moor DS Butterworth JC CoetzeeHydro-acoustic surveys have been used to provide annual estimates of May recruitment and November spawner biomass of the South African sardine Sardinops sagax and anchovy Engraulis encrasicolus resources since 1984. These time-series of abundance estimates form the backbone of the... -
Attenuation of the haemodynamic response to placement of the Mayfield skull pin head holder: alfentanil versus scalp block
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: FJ Smith --- Department of Anaesthesiology, Faculty of Medicine, South Africa CJ van der Merwe --- Department of Anaesthesiology, Faculty of Medicine, South Africa PJ Becker --- Unit for Biostatistics, South AfricaIntroduction: Application of the Mayfield clamp causes a significant haemodynamic response. Different methods have been used to attenuate this response. We compared two of these methods, namely alfentanil bolus (Group A) and nerve block of the scalp (Group B). METHOD:... -
Trophic state and nutrient limitation in Lake Baringo, Kenya
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: EO Okech --- Department of biological sciences, Kenya N Kitaka --- Department of biological sciences, Kenya SO Oduor --- Department of biological sciences, Kenya D Verschuren --- Department of Biology, BelgiumThe trophic state of Lake Baringo and factors that could be limiting the development of algal biomass in it were investigated during one wet/dry hydrological cycle in 2014–2015. Water samples were analysed for dissolved inorganic nutrients, including , and ,... -
The Elephant Marsh, Malawi – Part 2: two-dimensional hydrodynamic modelling in support of an eco-social assessment
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AL Birkhead --- , South Africa MK Reinecke --- , South Africa CA Brown --- , South Africa WO Mgoola --- , Malawi JK Nyirenda --- , MalawiThe Elephant Marsh lies on the floodplain of the lower Shire River, in southern Malawi. It is both a cultivated, seasonal floodplain and a wetland, characterised by a complex mosaic of meandering channels, marshland and shallow lakes. In 2016, the...