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On the concept of leaching requirement for salinity control
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H.M. du Plessis --- ,The concept of irrigating in excess of plant water requirement to restrict soil profile salinity to acceptable limits is well established. The tolerable upper salinity limit is used to calculate the leaching requirement. This upper limit is determined mainly by... -
Interaction of nitrogen fertilization and irrigation water salinity on growth of maize (Zea mays L.) in a two-way line-source sprinkler system
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: R.E. Steynberg --- Department of Plant Production, Republic of South Africa D. Magnusson --- , Israel Y. Ben-Asher --- , Israel M. Silberbush --- , IsraelMaize was planted in a line-source sprinkler experiment in the Negev Desert in Israel. A double line-source system was used with one line source at right angles to the other. It was possible to create a gradient of salt concentration... -
Influence of intensive irrigation and cultivation on selected soil properties: Arid southern Namibia
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: E. Verster --- Department of Geography, Republic of South Africa T.H. van Rooyen --- Department of Geography, Republic of South AfricaThe effect of long-term (25 years) intensive irrigation on selected soil properties of the Hardap Irrigation Scheme was determined by comparing soil profiles in irrigated and adjacent non-irrigated areas. The major differences detected between five soil pairs were rubification of... -
Calibration models for interpretation of soil salinity measurements using an electromagnetic induction technique
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.A. Johnston --- Department of Agronomy, Republic of South Africa M.J. Savage --- Department of Agronomy, Republic of South Africa J.H. Moolman --- Department of Soil and Agricultural Water Science, Republic of South Africa H.M. du Plessis --- , Republic of South AfricaA commercially available salinity sensor (model EM-38 of Geonics Ltd., Canada) has been developed for diagnosing and quantifying soil salinity in the field. There is a need, however, to calibrate the instrument reading against a more commonly used measure of... -
Tolerance of six Namaqualand pioneer species to saline soil conditions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.J. de Villiers --- Department of Botany (Soil Science), Republic of South Africa M.W. van Rooyen --- Department of Botany (Soil Science), Republic of South Africa G.K. Theron --- Department of Botany (Soil Science), Republic of South Africa A.S. Claassens --- Department of Botany (Soil Science), Republic of South AfricaSaline soils pose a great problem to reclamation of mined areas in arid regions. Experiments were carried out in order to determine the tolerance of six Namaqualand pioneer species to varying levels of salinity. Both perennial and ephemeral species were... -
Effects of Casuarina-amended soil on selected soil and citrus properties
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.W. Mashela --- Department of Plant Production, Republic of South AfricaEffects of beefwood (Casuarina cunninghamiana Miq.) leaf residues were evaluated on soil pH, soil electrical. conductivity, growth and foliar nutrient ions of rough lemon (Citrus jambhiri Hush) seedlings in two greenhouse experiments. Casuarina- amended soil reduced soil pH, root weight,... -
Acidic iron oxide waste as a conditioner for calcareous soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: R. Campbell --- Department of Soil Science, Republic of South Africa R.D. O'Brien --- Department of Soil Science, Republic of South Africa M.V. Fey --- Department of Soil Science, Republic of South AfricaA fine-grained iron oxide (hematite, (α-Fe2O3), containing 1.2% hydrochloric acid by mass, is the main by-product of an acid recovery plant at Saldanha Bay. The alkalinity of calcareous soils in this semi-arid region causes plant deficiencies in many trace elements,... -
Effects of sodium sulphate, sodium chloride and manganese sulphate on kikuyu (Pennisetum clandestinum) growth and ion uptake
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.J. Mills --- Department of Soil Science, South Africa M.V. Fey --- Department of Soil Science, South Africa C.E. Johnson --- Department of Civil and Environmental Engineering, USAIrrigation with saline water is increasingly practised yet an understanding of plant response to different salt types remains largely elusive. Our study investigated the effects of irrigation with simulated effluent containing three salts on the growth and composition of a... -
Amaranthus tricolor L. leaf yields affected by salinity, harvesting stage and harvesting methods
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. E.M.M. Ribeiro --- Department of Agronomy, South Africa N. J.J. Combrink --- Department of Agronomy, South AfricaSingle Amaranthus tricolor seedlings were transplanted into containers filled with 5 I river sand and were fertigated with a ‘drain to waste’ system. Plants were grown in the open under warm summer conditions. Four to six daily applications of nutrient... -
Regional sustainability in table grape production on saline soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: W. P. de Clercq --- Department of Soil Science, South Africa M. Van Meirvenne --- Department of Soil Management and Soil Care, BelgiumA study was done in South Africa to investigate the state of the soil salt content and its effect on plant growth on a regional rather than a point basis. The study site went through a development phase since 1996... -
Ameliorative effects of calcium on growth and mineral uptake of salt-stressed amaranth
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: E.N. Ornami --- Department of Plant Production and Soil Sciences, South Africa P.S. Hammes --- Department of Plant Production and Soil Sciences, South AfricaThe detrimental effects of salinity stress in plants may be ameliorated by calcium. However, little is known concerning the efficacy of different calcium sources, especially in amaranth. Two amaranth genotypes (Amaranthus tricolor and A. cruentus) were grown in a greenhouse... -
A NOTE ON SALINITY AND OXYGEN STRATIFICATION IN THE MARINA DA GAMA, ZANDVLEI
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: B.R. Davies --- Zoology Department, Republic of South Africa B.A. Stewart --- Zoology Department, Republic of South AfricaTen months data (March to December, 1983), on temperature, salinity and dissolved oxygen are reported for two canals within the Marina Da Gama, Zandvlei, a coastal lake periodically open to the sea. They show that although there was minimal temperature... -
FUTURE CHALLENGES IN WATER QUALITY MODELLING WITH PARTICULAR REFERENCE TO OPERATIONALLY CLOSED CATCHMENTS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: S.F. Forster --- Department of Water Affairs, South Africa F.A. Stoffberg --- Department of Water Affairs, South Africa J.A. van Rooyen --- Department of Water Affairs, South AfricaAs a result of the declining quality of many water sources, the use of water quality models in planning is increasing. To date applications have involved the simulation of total dissolved salts and nutrients, largely in catchments affected by urban... -
Pitfalls in the Presentation of Chemical Data
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: J.A. Day --- Zoology Dept, South AfricaBiologists in the aquatic sciences are often guilty of numerous errors in the presentation of their chemical data. This paper reviews the use of units in the representation of the inorganic constituents of aquatic solutions for their benefit. It explains... -
A CHARACTERIZATION OF SOUTHERN AFRICAN ESTUARINE SYSTEMS
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: A.K. Whitfield --- , South AfricaModifications to the structure and functioning of southern African estuarine systems can be placed into two major categories; those changes that have been driven by global forces such as climatic and sea-level fluctuations, and those that have resulted from direct... -
MASS MORTALITY OF MARINE AND ESTUARINE FISH IN THE SWARTVLEI AND WILDERNESS LAKE SYSTEMS, SOUTHERN CAPE.
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: I.A. Russell --- National Parks Board, South AfricaTwo incidences of mass mortality of fish were recorded in two saline waterbodies (Swartvlei estuary and Rondevlei) in the Wilderness National Park. Species affected were the Knysna seahorse (Hippocampus capensis) and longsnout pipefish (Syngnathus acus) in the Swartvlei estuary, and... -
MASS MORTALITIES OF FISH IN SOUTH AFRICAN ESTUARIES
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: A.K. Whitfield --- , South AfricaChanges to the physico-chemical environment have been identified as the cause of fish mass mortalities in South African estuaries. Most published accounts have linked these mortalities to a single dominant factor such as low salinity, low or high temperature, low... -
INFLUENCE OF FRESHWATER FLOW REGIME ON FISH ASSEMBLAGES IN THE GREAT FISH RIVER AND ESTUARY
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: L.D. Ter Morshuizen --- , South Africa A.K. Whitfield --- , South Africa A.W. Paterson --- , South AfricaTwo and a half years of data were collected from the lower Great Fish River, head region and estuary to determine the fish species composition within these areas. Gilchristella aestuaria, Liza dumerilii, Rhabdosargus holubi and Pomadasys commersonnii were the four... -
WATER TEMPERATURE AND THE 1987 FISH KILL AT LAKE ST LUCIA ON THE SOUTH EASTERN COAST OF AFRICA
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: D.P. Cyrus --- Coastal Research Unit of Zululand, Department of Zoology, South Africa S. McLean --- Coastal Research Unit of Zululand, Department of Zoology, South AfricaAn unusually cold spell during the winter of 1987 caused a drop in water temperature at Lake St Lucia. This coupled with typical estuarine salinities in the lake resulted in a fish kill. The kill was one of the largest... -
SALINITY, FLOODS AND THE INFAUNAL MACROBENTHIC COMMUNITY OF THE ST LUCIA ESTUARY, KWAZULU-NATAL, SOUTH AFRICA
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: R. K. Owen --- , , South Africa A. T. Forbes --- , , South AfricaThe St Lucia estuary and lake comprise some 80 % of the estuarine area of KwaZulu-Natal. The system is subject to floods and hypersaline conditions, the latter twice exceeding 100 since 1970. The lake is connected to the sea by... -
MANAGING THE ST. LUCIA ESTUARY—MESSAGES FROM THE MUD
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: R. K. Owen --- , , South Africa A. T. Forbes --- , , South AfricaThe infaunal macrobenthic community of the St Lucia estuary has been exposed to natural disturbance in the form of salinity fluctuations arising from floods and hypersaline conditions, and human-induced interference arising from dredging and beam trawling. The responses of the... -
Effects of the 2000 southern Mozambique floods on a marginal coral community: the case at Xai-Xai
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: MarcosAM Pereira Paulo MiguelB GonçalvesIn early 2000 the southern part of Mozambique suffered the worst flooding in 50 years, causing fatalities and considerable material loss. This study aimed to investigate the impact of this flood on the coral communities in Xai-Xai lagoon. Benthic cover... -
The distribution and habitat in the Knysna Estuary of the endemic South African mudsnail Hydrobia knysnaensis and the influence of intraspecific competition and ambient salinity on its abundance
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Rsk BarnesThe typical habitat of the rare, endemic South African mudsnail Hydrobia knysnaensis is the leaves of upper-shore Zostera capensis within high-salinity salt-marsh pools and channels. In the Knysna estuarine system, it is the numerically dominant member of a guild of... -
Primary habitats of the St Lucia Estuarine System, South Africa, and their responses to mouth management
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Ricky Taylor JanineB Adams Sylvi HaldorsenFour primary habitats have been identified in the St Lucia estuarine system, each having a suite of characteristic vegetation types. These can be described as follows: (1) open water; (2) intertidal shoreline; (3) 'dry' shoreline and island (i.e. those habitats... -
Status of the estuarine fish fauna in the St Lucia Estuarine System, South Africa, after 30 months of mouth closure
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Digby Cyrus Leon VivierThe Lake St Lucia Estuarine System, South Africa, has been under pressure due to recent drought conditions, which led to extreme low lake levels, hypersaline conditions and closure of the mouth. The estuary mouth closed in June 2002 and has... -
Salinity tolerance of the burrowing ocypodid crab, Paratylodiplax blephariskios, in the St. Lucia and Mhlathuze estuaries, KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: RK Owen --- Department of Zoology, South Africa AT Forbes --- , South AfricaThe ocypodid crab, Paratylodiplax blephariskios, is endemic to the southeast coast of southern Africa where it forms an important component of the estuarine benthic fauna in muddy substrata. The St. Lucia and Mhlathuze estuaries are two of the largest estuaries... -
Initial characterisation of the mesozooplankton community of the Mfolozi– Msunduzi estuarine system, KwaZulu-Natal, South Africa, during a low-flow period
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HL Jerling --- Coastal Research Unit of Zululand, Department of Zoology, South Africa L Vivier --- Coastal Research Unit of Zululand, Department of Zoology, South Africa DP Cyrus --- Coastal Research Unit of Zululand, Department of Zoology, South Africa RK Owen --- Coastal Research Unit of Zululand, Department of Zoology, South AfricaThe mesozooplankton of the Mfolozi and Msunduzi estuaries, which share a combined mouth, was sampled twice per year during a two-year period of relatively low river flow. Samples were collected during March, after the rainy season when the estuary mouth... -
The potential for zoobenthic fauna dispersal into the St Lucia Estuary from the Mfolozi–Msunduzi estuarine system, KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: RK Owen --- Coastal Research Unit of Zululand, Department of Zoology, South Africa DP Cyrus --- Coastal Research Unit of Zululand, Department of Zoology, South Africa L Vivier --- Coastal Research Unit of Zululand, Department of Zoology, South Africa HL Jerling --- Coastal Research Unit of Zululand, Department of Zoology, South AfricaThe onset of a prolonged drought in the St Lucia catchment in 2002 and subsequent mouth closure raised concern for the biota of the estuary. Ezemvelo KZN Wildlife proposed a scheme whereby the Mfolozi–Msunduzi mouth would be closed, causing fresh... -
Spatio-temporal variability of surface water quality parameters in a South African estuarine lake system
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: IA Russell --- , South AfricaLong-term (20+ years) water quality datasets for estuaries are rare, especially for smaller systems. Monitoring of salinity, temperature, pH, dissolved oxygen and turbidity has been undertaken since 1991 in the intensively utilised, modified, and managed temporarily open/closed Touw Estuary and... -
Response of mangroves to drought and non-tidal conditions in St Lucia Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: SCL Hoppe-Speer --- Botany Department, South Africa JB Adams --- Botany Department, South Africa A Rajkaran --- Botany Department, South AfricaThe effect of a prolonged closed-mouth state on the condition of mangrove habitats was studied in May 2010 at St Lucia Estuary, KwaZulu-Natal. The mouth had been closed to the sea since 2002 as a result of artificial mouth closure... -
FUTURE CHALLENGES IN WATER QUALITY MODELLING WITH PARTICULAR REFERENCE TO OPERATIONALLY CLOSED CATCHMENTS
Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: S.F. Forster --- Department of Water Affairs, South Africa F.A. Stoffberg --- Department of Water Affairs, South Africa J.A. van Rooyen --- Department of Water Affairs, South AfricaAs a result of the declining quality of many water sources, the use of water quality models in planning is increasing. To date applications have involved the simulation of total dissolved salts and nutrients, largely in catchments affected by urban... -
A test of an autonomous underwater vehicle as a monitoring tool in shallow water
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PA Tester SR Kibler B Hobson RW LitakerThe utility of micro-autonomous underwater vehicles (AUVs) to detect hydrographic features that concentrate phytoplankton cells was evaluated during a study in a shallow tidal estuary. This study represented the first field test of Ranger™, a micro-AUV adapted for environmental applications... -
Composition, abundance, distribution and seasonality of larval fishes in the Mngazi Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: P Pattrick NA Strydom TH WooldridgeWe investigated the larval fish assemblage in the intermittently-open Mngazi Estuary, in the subtropical/warm-temperate biogeographic boundary region of South Africa. Larvae were collected by means of boat-based plankton tows in summer and winter for a period of three years between... -
The response of the diatom flora of St Lucia Lake and estuary, South Africa, to a severe drought
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: GC Bate PA SmailesLake St. Lucia, South Africa's largest estuarine system, was isolated from the sea by a beach berm throughout a severe drought from 2002 to 2007, with the lake water level being extremely low over much of its total area. A... -
Effect of salinity on growth of juvenile silver kob, Argyrosomus inodorus (Teleostei: Sciaenidae)
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HL Ferreira NG Vine CL Griffiths H KaiserAs part of the evaluation of new aquaculture species, the effect of environmental factors on growth, food conversion ratio and survival should be tested. In this study silver kob, Argyrosomus inodorus, were reared for 98 days at three salinities, of... -
Fish community response to increased river flow in the Kariega Estuary, a freshwater-deprived, permanently open southern African system
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: PD Vorwerk PW Froneman AW Paterson AK WhitfieldThe littoral and demersal ichthyofaunal community structure in the freshwater-deprived, permanently open Kariega Estuary was investigated following heavy rain in November 2006 and was compared to low-flow condition data from 1991 and 1996. All surveys took place during the spring... -
Composition and abundance of the zooplankton community in the Bitter Lakes, Egypt, in relation to environmental factors
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: RA El-BassatThe taxonomic composition of the zooplankton community of the Bitter Lakes, Egypt, was examined in 2003–2004 in relation to the spatial and temporal distribution of environmental factors. Copepoda were dominant, forming 49% of the zooplankton, followed by Protista at 37%... -
Comparison of, and the effects of altered freshwater inflow on, fish assemblages of two contrasting South African estuaries: the cool-temperate Olifants and the warm-temperate Breede
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SJ Lamberth L van Niekerk K HutchingsThis study compares the fish assemblages of the permanently open cool-temperate Olifants and warm-temperate Breede estuaries on the west and south coasts of South Africa respectively, and their responses to altered freshwater flows. Both estuaries have experienced a >35% reduction... -
A multidisciplinary study of a small, temporarily open/closed South African estuary, with particular emphasis on the influence of mouth state on the ecology of the system
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: AK Whitfield JB Adams GC Bate K Bezuidenhout TG Bornman PD Cowley PW Froneman PT Gama NC James B Mackenzie T Riddin GC Snow NA Strydom S Taljaard AI Terörde AK Theron JK Turpie L van Niekerk PD Vorwerk TH WooldridgeIn 2005/2006 a multidisciplinary research programme that included studies on the hydrodynamics, sediment dynamics, macronutrients, microalgae, macrophytes, zoobenthos, hyperbenthos, zooplankton, ichthyoplankton, fish and birds of the temporarily open/closed East Kleinemonde Estuary was conducted. Particular attention was given to the responses... -
Comparative salinity tolerances of four siphonariid limpets in relation to habitat restriction of the rare and endangered Siphonaria compressa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: G Wilson --- Marine Biology Research Centre, Department of Zoology, South Africa GM Branch --- Marine Biology Research Centre, Department of Zoology, South Africa P de Coito --- Marine Biology Research Centre, Department of Zoology, South AfricaThe salinity tolerances of four South African species of limpet in the genus Siphonaria were experimentally tested, in the context that one of them, S. compressa, is South Africa's most endangered marine mollusc and is restricted to two lagoonal localities... -
Nitrogen uptake dynamics of a persistent cyanobacterium Cyanothece sp. bloom in Lake St Lucia, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SJ du Plooy --- DST/NRF Research Chair in Shallow Water Ecosystems, South Africa AJ Smit --- School of Life Sciences, South Africa R Perissinotto --- DST/NRF Research Chair in Shallow Water Ecosystems, South Africa DG Muir --- Department of Biology, Medgar Evers College, USAWorldwide, persistent cyanobacterial blooms are becoming more frequent and are often associated with effects of global climate change. In June 2009, a widespread bloom of the unicellular cyanobacterium, Cyanothece sp., appeared in North Lake and False Bay of Lake St... -
Temporal and spatial variability in the abundance, biomass and distribution of Palaemon peringueyi (Decapoda: Crustacea) are influenced by biological but not physico-chemical factors in the permanently open Kariega Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: NP Nyalungu --- South African National Parks, Cape Research Centre, South Africa AN Hodgson --- Department of Zoology and Entomology, South Africa PW Froneman --- Department of Zoology and Entomology, South Africa M Dopolo --- South African National Parks, Cape Research Centre, South Africa M Masubelele --- South African National Parks, Cape Research Centre, South AfricaBiological and physico-chemical factors affecting abundance and biomass of shrimp Palaemon peringueyi were investigated in 2010–2011 in the lower, middle and upper reaches of the freshwater-deprived permanently open Kariega Estuary. Shrimp abundance and biomass ranged from 0 to 88 ind... -
The influence of selected environmental parameters on the distribution of the dominant demersal fishes in the Kariega Estuary channel, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Naomi Richardson --- Department of Ichthyology and Fisheries Science, South Africa Alan K. Whitfield --- South African Institute for Aquatic Biodiversity, South Africa Angus W. Paterson --- South African Institute for Aquatic Biodiversity, South AfricaThe Kariega Estuary channel was sampled using an otter trawl and the demersal fish catch analysed using the PRIMER statistical package. A biological-environmental (BIOENV) analysis was undertaken using the catch per unit effort ichthyofaunal data from the spring/summer period of... -
Aspects of the biology and ecology of the estuarine cirolanid isopod, Cirolana fluviatilis
Item type: Journal Article • Journal: African Zoology • Authors: Brent K. Newman --- Department of Zoology, South Africa Tristram H. Wooldridge --- Department of Zoology, South Africa Andy C. Cockcroft --- Department of Environmental Affairs and Tourism, Marine and Coastal Management Branch, South AfricaTrends in the distribution, population dynamics and reproductive biology of the estuarine cirolanid isopod, Cirolana fluviatilis, were investigated over a 12-month period in the warm–temperate Gamtoos River Estuary, by means of baited traps. Tolerance of adult isopods to combinations of... -
Effects of temperature and salinity on resting metabolism in two South African rock pool fish: the resident gobiid Caffrogobius caffer and the transient sparid Diplodus sargus capensis
Item type: Journal Article • Journal: African Zoology • Authors: J. O. G. Kemp [AN0001]Intertidal rock pools are inherently dynamic environments that experience marked changes in physico-chemical parameters over diel, tidal and seasonal time scales. Fish that inhabit the intertidal zone can generally be characterized as either permanent residents or transients/visitors. This study investigates... -
Composition, abundance, distribution and seasonality of larval fishes in the Sundays Estuary, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: K. Sutherland --- Department of Zoology, South Africa N.A. Strydom --- Department of Zoology, South Africa T.H. Wooldridge --- Department of Zoology, South AfricaThe larval fish assemblage was studied in the permanently open Sundays Estuary on the southeast coast of South Africa. Seasonal samples were collected between winter 2007 and autumn 2009 at eight sites along the estuary by means of boat-based plankton... -
Spatial distribution and community structure of phytoplankton, ciliates and zooplankton coupled to environmental factors in the Sousse saltern (Sahel of Tunisia)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: S Ghannay --- Faculté des Sciences de Sfax, Tunisia H Khemakhem --- Faculté des Sciences de Sfax, Tunisia H Ayadi --- Faculté des Sciences de Sfax, Tunisia J Elloumi --- Faculté des Sciences de Sfax, TunisiaThe composition and distribution of the main planktonic halophilic microorganisms were studied in 12 ponds of different salinity levels, ranging from 38 to 328, in the saltern of Sousse, Tunisia, in relation to environmental factors. Nutrient concentrations increased with decreasing... -
Spatio-temporal variability of five surface water quality parameters in the Swartvlei estuarine lake system, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: IA Russell --- South African National Parks, South AfricaVariability of salinity, temperature, pH, dissolved oxygen and turbidity in the temporarily open/closed Swartvlei estuarine system, measured from 1991 to 2013, was investigated at various temporal (seasonal, estuarine open/closed phase, long-term) and spatial (inter- and intra-waterbody) scales. Longitudinal pH and... -
Affinities of some common estuarine macroinvertebrates to salinity and sediment type: empirical data from Eastern Cape estuaries, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Peter R. Teske --- Department of Zoology, South Africa Tris H. Wooldridge --- Department of Zoology, South AfricaFourteen species of subtidal macrobenthos present in thirteen Eastern Cape estuaries, South Africa, were compared with regard to correlations with two important environmental variables (salinity and sediment mud content). Species were divided into five different faunal components based on their... -
Growth and longevity of Exosphaeroma hylocoetes (Isopoda) under varying conditions of salinity and temperature
Item type: Journal Article • Journal: African Zoology • Authors: T.O. Henninger --- Department of Zoology and Entomology, South Africa P.W. Froneman --- Department of Zoology and Entomology, South Africa A.J. Booth --- Department of Ichthyology and Fisheries Science, South Africa A.N. Hodgson --- Department of Zoology and Entomology, South AfricaThe effect of temperature (15 and 25°C) and salinity (15 and 35 practical salinity units) combinations on the growth and longevity of the South African estuarine isopod Exosphaeroma hylocoetes was investigated and data analysed using the logistic growth model. No... -
Changes in the algal composition and water quality of the Sundays River, Karoo, South Africa, from source to estuary
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: S Janse van Vuuren --- Unit for Environmental Sciences and Management, South Africa JC Taylor --- Unit for Environmental Sciences and Management, South AfricaA first survey was done on algae present in the Sundays River from its source to its confluence with the sea. Species found in the upstream sections of the river included indicators of good water quality, but the quality deteriorated... -
Subtidal macrozoobenthic community resilience to change following natural mouth breaching of the temporarily open/closed East Kleinemonde Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: TH Wooldridge --- Department of Zoology, South Africa K Bezuidenhout --- Department of Zoology, South AfricaThe East Kleinemonde Estuary, on the south-east coast of South Africa, typically opens for only short periods, usually <10 days. During a nine-month study in 2006, marine influence persisted for a near-continuous period of three months. This provided an opportunity... -
Past and present fish species recorded in the estuarine Lake Ichkeul, northern Tunisia
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: M Shaiek --- Research Unit Ecosystems and Aquatic Resources (UR13AGRO1), National Agronomy Institute of Tunisia (INAT), Tunisia C Fassatoui --- Research Unit Ecosystems and Aquatic Resources (UR13AGRO1), National Agronomy Institute of Tunisia (INAT), Tunisia MS Romdhane --- Research Unit Ecosystems and Aquatic Resources (UR13AGRO1), National Agronomy Institute of Tunisia (INAT), TunisiaLake Ichkeul in northern Tunisia is a Ramsar site, a MAB Biosphere Reserve and a UNESCO World Heritage Site. The system is one of the most important coastal wetlands in North Africa, especially as an over-wintering area for migratory birds,... -
Suspended silt and salinity tolerances of the first zoeal stage of the fiddler crab Uca annulipes (Decapoda: Brachyura) and why marine connectivity is essential to the survival of the species
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: N Peer --- DST/NRF Research Chair in Shallow Water Ecosystems, South Africa NAF Miranda --- DST/NRF Research Chair in Shallow Water Ecosystems, South Africa R Perissinotto --- DST/NRF Research Chair in Shallow Water Ecosystems, South AfricaFiddler crabs (Uca spp.) undergo the zoeal stage of development in open-ocean waters, where they experience stable salinity levels, low turbidity and reduced predation. The St Lucia estuarine system has undergone many geomorphological changes, both natural and anthropogenic, and the... -
Agronomic performance of early segregating generations of rice under salt stress in Niger
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Oumarou Souleymane --- Institut National de la recherche Agronomique du Niger, culture irriguée, Niger Baboucarr Manneh --- Africa Rice Center, Senegal Eric Nartey --- University of Ghana, Ghana Kwadwo Ofori --- University of Ghana, Ghana Eric Danquah --- University of Ghana, GhanaSalinity is a major abiotic constraint that retrains rice production worldwide. The development and release of rice cultivars with improved performance in saline environments is essential to fight against this scourge. Hence this study was carried out to evaluate segregating... -
Subfossil diatoms from Hann Park pond, Dakar, Senegal: floristic inventory and palaeoenvironmental reconstruction
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: I Badiane --- Département de Géologie, Faculté des Sciences et Techniques, E Sow --- Département de Géologie, Faculté des Sciences et Techniques, CAK Fofana --- Département de Géologie, Faculté des Sciences et Techniques, C Aw --- Département de Géologie, Faculté des Sciences et Techniques,Diatoms in a 100 cm-long core from a pond in Hann Forest Park, western Senegal, were studied with the aim of reconstituting this interdune depression’s history, particularly the human influence, during the last century. Sixty-three species and varieties of diatoms... -
Mesozooplankton community structure changes in the Mfolozi–Msunduzi estuarine system, South Africa, during contrasting river flow conditions
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HL Jerling --- Coastal Research Unit of Zululand, Department of Zoology, South Africa DP Cyrus --- Coastal Research Unit of Zululand, Department of Zoology, South AfricaThe Mfolozi–Msunduzi estuarine system is subject to periodic dry and wet cycles, with subsequent changes in the abiotic and biotic characteristics of the system. The aim of the current study was to compare its mesozooplankton composition during relatively dry and... -
Quantification of primary salinity, sodicity and alkalinity in South African soils using climate regions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J Piet Nell --- Agricultural Research Council–Institute for Soil, South Africa Cornelius W van Huyssteen --- Department of Soil, Crop and Climate Science, South AfricaNo reliable primarily salinity, sodicity and alkalinity information is available for South Africa, nor are there monitoring programs in place to track the salt-affected status of South African soils. Such information is, however, needed for various agricultural and environmental studies... -
Microfossils in surface sediments of brackish waters on the west coast of South Africa and their palaeoecological implications
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: S Fürstenberg --- Institute of Geosciences, Friedrich Schiller University Jena, Germany N Gründler --- Institute of Geosciences, Friedrich Schiller University Jena, Germany S Meschner --- Institute of Geosciences, Friedrich Schiller University Jena, Germany P Frenzel --- Institute of Geosciences, Friedrich Schiller University Jena, GermanyA faunistic survey covering 25 sites in estuaries, coastal lakes and ponds along the west coast of South Africa between the Cape of Good Hope in the south and the Olifants River in the north was carried out in May... -
The impact of river flooding and high flow on the demersal fish assemblages of the freshwater-dominated Great Fish Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: P Nodo --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa NC James --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa A-R Childs --- Department of Ichthyology and Fisheries Science, South Africa MDV Nakin --- Department of Biological and Environmental Sciences, South AfricaFreshwater 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 climatic variability associated with climate change is predicated to modify precipitation patterns, which... -
Mesozooplankton of the Kosi Bay lakes, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HL Jerling --- Department of Zoology and Coastal Research Unit of Zululand, South Africa SP Weerts --- Department of Zoology and Coastal Research Unit of Zululand, South AfricaThe Kosi coastal lake system, a chain of four interconnected basins, is located in the subtropical north-eastern corner of South Africa. Little information is available on zooplankton of the system and the main aim of this study is to report... -
Derivation of scenario-specific water quality guidelines for acid mine drainage in South Africa, using a risk-based approach
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: EC Vellemu --- Unilever Centre for Environmental Water Quality, South Africa PK Mensah --- Unilever Centre for Environmental Water Quality, South Africa N Griffin --- Unilever Centre for Environmental Water Quality, South Africa ON Odume --- Unilever Centre for Environmental Water Quality, South AfricaAcid mine drainage (AMD) continues to threaten water quality in many mining regions globally. Data paucity renders it challenging to inform appropriate water quality management strategies for a succinct scientific understanding of the effects of AMD on freshwater ecosystems. The... -
The effect of Cymbopogon citratus aqueous leaf extract on Solanum lycopersicum seed germination and seedling growth under saline conditions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Taofik Sunmonu --- Department of Biological Sciences, Nigeria Aishat Mohammed Naibi --- Department of Biological Sciences, Nigeria Suaib Osineye --- Department of Chemical Sciences, Nigeria Hussein Oloyede --- Department of Biochemistry, NigeriaThe allelopathic potential of Cymbopogon citratus aqueous leaf extract on the germination of Solanum lycopersicum seeds under saline conditions was investigated in a laboratory bioassay. At the end of the eight-day trial, the seeds were evaluated for germination parameters and... -
Remediation of salt-affected soil by natural and chemical amendments to improve berseem clover yield and nutritive quality
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Zainab Mohamed Abd El-Naby --- Forage Research Department, Egypt Wafaa Abd El-Karim Hafez --- Soil, Water and Environment Research Institute, Agriculture Research Center, Egypt Hanan Ahmed Hashem --- Botany Department, Faculty of Science, EgyptSalinity is a major problem affecting crop production worldwide. The potential of different soil amendments (sulphur, gypsum, compost, and combination of gypsum, compost and sulphur) and two plant-growth stimulators (potassium silicate and calcium carbonate nanoparticles) to alleviate the harmful effects... -
Seasonal cycle of the salinity barrier layer revealed in the northeastern Gulf of Guinea
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: AN Dossa --- International Chair in Mathematical Physics and Applications (ICPMA-UNESCO Chair), Benin CY Da-Allada --- International Chair in Mathematical Physics and Applications (ICPMA-UNESCO Chair), Benin G Herbert --- Institut de Recherche pour le Développement (IRD), Instrumentation, Moyens Analytiques, France B Bourlès --- Institut de Recherche pour le Développement (IRD), Instrumentation, Moyens Analytiques, FranceThe region located in the far northeast of the Gulf of Guinea (NEGG), eastern tropical Atlantic, remains poorly documented due to a lack of available in situ ocean data. Heavy rainfall and intense river discharges observed in this region induce... -
The development and implementation of a management plan for the Seekoei Estuary, South Africa: a case study guided by socio-economic issues
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: TH Wooldridge --- Department of Zoology and Institute for Coastal and Marine Research, South Africa JB Adams --- Department of Botany and Institute for Coastal and Marine Research, South AfricaThe large Temporarily Closed Seekoei Estuary has a long history of poor management. In 1969, a swimming pool complex was built in a position impinging on the mouth. The construction of a 500 m causeway across the lagoon connecting the... -
Biomass partitioning in an endemic southern African salt marsh species Salicornia tegetaria (Chenopodiaceae)
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: CE Brown --- Department of Biodiversity and Conservation Biology, South Africa A Rajkaran --- Department of Biodiversity and Conservation Biology, South AfricaThe below ground biomass of salt marsh species accounts for more than half of the total plant biomass in salt marsh systems, yet no biomass data exist for salt marsh species in South Africa. The aims of the current study... -
Effects of prolonged mouth closure in a temporarily open/closed estuary: a summary of the responses of invertebrate communities in the uMdloti Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: UM Scharler --- School of Life Sciences, South Africa K Lechman --- School of Life Sciences, South Africa T Radebe --- School of Life Sciences, South Africa HL Jerling --- Department of Zoology, South AfricaProlonged mouth closure in estuaries is often associated with hypersalinity, mainly as a result of reduced freshwater inflow. However, on the KwaZulu-Natal coast, South Africa, temporarily open/closed estuaries have a tendency towards hyposalinity during closed mouth conditions, primarily because of... -
Revegetation of marginal saline rangelands of southern Tunisia using pastoral halophytes
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Abderrazak Tlili --- , Tunisia Emna Ghanmi --- , Tunisia Naziha Ayeb --- , Tunisia Mounir Louhaichi --- , Jordan Mohamed Neffati --- , Tunisia Mohamed Tarhouni --- , TunisiaRevegetation of marginalised rangelands using pastoral halophytes is considered an appropriate scientific and environmental approach to rehabilitation. Atriplex halimus L. (Amaranthaceae), A. mollis Desf. (Amaranthaceae), Cenchrus ciliaris L. (Poaceae) and Lotus creticus L. (Fabaceae) are promising species for arid rangeland... -
Response of malt barley grain quality characteristics to increasing irrigation water salinity
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: VN Mathinya --- , South Africa JH Barnard --- , South Africa ZA Bello --- , South Africa E van der Watt --- , South AfricaPremiums are offered for high quality grain, but producers of malting barley are often confronted with marginal soils and water scarcity. Irrigation water quality is often low, primarily due to high salt loads. This study determined the effect of irrigation... -
Phytoplankton community structure in relation to physico-chemical factors in a tropical soda lake, Lake Shala (Ethiopia)
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Solomon Wagaw --- , Ethiopia Seyoum Mengistou --- , Ethiopia Abebe Getahun --- , EthiopiaPhytoplankton communities responses to physico-chemical factors were studied in Lake Shala from January to December 2018. Distinct spatial and seasonal variations were observed for all physico-chemical parameters, except DO (ANOVA: p < 0.05). In total, 72 taxa, Bacillariophyta (55 taxa),... -
The ecology of coastal wetland ponds created by diamond mining in southern Namibia. 1. Physical conditions
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L Maritz --- , South Africa D Pillay --- , South Africa GM Branch --- , South AfricaCoastal diamond mining in southern Namibia involves constructing seawalls to hold the sea at bay, and seaward accretion of the shoreline by up to 800 m opens what was previously the surf zone for excavation and extraction of bedrock alluvial... -
The ecology of coastal wetland ponds created by diamond mining in southern Namibia. 2. Saltmarsh vegetation
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L Maritz --- , South Africa D Pillay --- , South Africa GM Branch --- , South AfricaDiamond mining on the southern Namibian coastline has created multiple large coastal ponds of up to 380 000 m2 adjacent to the coastline, as the sea overtops erected seawalls or seeps into excavated areas. These ponds span ages of 1–38... -
The application of Bayesian networks to evaluate risks from multiple stressors to water quality of freshwater ecosystems
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: V Wepener --- , South Africa GC O’Brien --- , South AfricaIt is difficult to predict and manage the ecological consequences of multiple water quality stressors on our freshwater systems. This is due to the dynamism of the source-stressor-response relationships and multiple factors including lack of data, complex impact pathways and... -
Spatial patterns and environmental drivers of demersal fish assemblages in the Swartkops and Sundays estuarine to marine seascapes, South Africa
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: P Nodo --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa AR Childs --- Rhodes University, South Africa P Pattrick --- Nelson Mandela University, South Africa NC James --- South African Institute for Aquatic Biodiversity (SAIAB), South AfricaEstuaries are often observed as the boundary between the ocean and the river, separating coastal environments, rather than being seen as a continuum. Owing to insufficient research on demersal fish communities across nearshore marine to estuarine habitats, particularly in South... -
Benthic macrofaunal changes in response to restoration efforts in the St Lucia estuarine lake, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PC Moloi --- School of Agriculture and Science, University of KwaZulu-Natal, South Africa GM Rishworth --- Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, South Africa MS Bird --- Department of Zoology, University of Johannesburg, South Africa NK Carrasco --- School of Agriculture and Science, University of KwaZulu-Natal, South AfricaThe St Lucia estuarine lake and Mfolozi River mouth on the Indian Ocean coast of South Africa were once a single, connected system but were artificially separated in 1952 to prevent siltation from the Mfolozi River catchment which risked shallowing...