Rivers In Africa Research Articles

Filling in the knowledge gap: Observing MacroPlastic litter in South Africa's rivers

Only 12% of the world's published plastic research includes references to Africa despite it being a significant contributor to the global plastic waste and mismanagement problem (~88.5% of Africa's plastic waste is mismanaged). Ocean plastics are transported from land by rivers to the sea. However, source contextualization is complex. Many African rivers predominantly run alongside human settlements that host informal waste dumpsites. In this study a simple cost effective, easily deployed, consistent and replicable survey methodology was employed. The study quantified macroplastic in three rivers discharging into Algoa Bay, South Africa. The results indicated that industrial Swartkops and metropolitan Baakens Rivers both illustrate moderate plastic pollution (>3000 plastic particles/day), with the relatively natural Sundays River to showing minimal evidence of river macro plastic (<100 plastic particles/day). The types of plastic were noted using the RIMMEL app (premier African implementation), enabling proportional comparison of different plastic litter types to be completed.

MAKING RAIN, MAKING MAPS: COMPETING GEOGRAPHIES OF WATER AND POWER IN SOUTHWESTERN AFRICA

AbstractThis article explores the alchemy whereby ritual and political worlds invisible to Europeans were rendered visible on European maps. It begins with a puzzle: representations of southwestern Africa's rivers on those maps bear little resemblance to physical reality as the cartographers would have understood it. Using GIS technology to georeference a series of maps and highlight the placement of rivers on them illustrates the convergence of cartographers’ representations and regional political cosmologies linking power to control over water. Travelers’ accounts and colonial archives illuminate how knowledge was produced and why African ideas about geography were inadvertently embedded in those maps well into the twentieth century. This method opens a window into otherwise-obscured African intellectual history and demonstrates that even something as apparently and unambiguously ‘European’ as modern mapping was the result of on-the-ground negotiations well into the colonial period.

Urban effluent discharges as causes of public and environmental health concerns in South Africa's aquatic milieu.

The water quality in South Africa's river systems is rapidly deteriorating as a consequence of increased discharge of wastewater effluents. The natural ability of rivers and reservoirs to trap toxic chemicals and nutrients in their sediments enables these systems to accumulate contaminants, altering the natural balance in environmental water quality, thereby raising a plethora of public and environmental health concerns. Impaired water quality has been linked to an array of problems in South Africa including massive fish mortalities, altered habitat template leading to the thinning of riverine macroinvertebrate diversity, shifts in microbial community structures with drastic ecological consequences and evolvement of antibiotic resistance genes that, under natural conditions, can be transferred to waterborne pathogens. Urban wastewater discharge has also been implicated in increased bioaccumulation of metals in edible plant parts, elevated concentrations of endocrine-disrupting compounds (EDCs), which are blamed for reduced fertility and increased cancer risk, excessive growth of toxic cyanobacteria and an increase in concentrations of pathogenic microorganisms which constitute a potential health threat to humans. However, despite the ecotoxicological hazards posed by wastewater effluents, ecotoxicological studies are currently underutilised in South African aquatic ecosystem assessments, and where they have been done, the observation is that ecotoxicological studies are mostly experimental and restricted to small study areas. More research is still needed to fully assess especially the ecotoxicological consequences of surface water pollution by urban wastewater effluents in South Africa. A review of the effects of urban effluent discharges that include domestic effluent mixed with industrial effluent and/or urban stormwater run-off is hereby presented.

High levels of genetic structure and striking phenotypic variability in a sexually dimorphic suckermouth catfish from the African Highveld

© 2015 The Linnean Society of London. Uncovering biological diversity to more accurately understand diversity patterns, and ultimately the processes driving diversification, is important not only from an evolutionary perspective but also a conservation perspective. This is particularly pertinent in Africa's rivers in which overall diversity, as well as how it arose, is poorly understood in comparison with lacustrine environments. Here we investigate population divergence in the sexually dimorphic suckermouth catfish species Chiloglanis anoterus (Crass, 1960) from the African Highveld, in which we observe striking variability in exaggerated male caudal fins across its range. As this trait is likely to be indirect evidence for sexual selection by female choice, a mechanism that has been shown to increase species diversity in different taxa, we used an integrated approach to test if current diversity in this species is underestimated. Results based on phylogenetic inference, population genetics and geometric morphometrics indicate that the recognized species C. anoterus represents five distinct lineages that may be considered confirmed candidate species. We suggest that diversification in these highland catfish has been facilitated through geographical isolation in upper river catchments, and that sexual selection through female choice has probably driven variation in male caudal fin morphology. In contrast to the relatively large range size of the currently recognized species (C. anoterus), our findings highlight highly restricted ranges of the lineages identified here, indicating that these highland habitats may harbour higher levels of endemic diversity than previously thought.

Developing the rivers of East and West Africa: an environmental history

1. Introduction: Harnessing Africa's Waters Part One: From the river's edge 2. Unpredictable blessings: Life along the Rufiki River, Tanzania 3. Mapping a Continent: British exploration of the Niger River Part Two: Colonizing Africa's rivers 4. Greening the Fields: Agricultural development during the colonial period 5. Electrifying the Empire: Debates about power production in Africa Part Three: The changing value of rivers 6. The damming of Africa: Converting African water to hydropower 7. Thirsty cities: Urbanization and the changing values of African rivers Epilogue: Managing Africa's Rivers in the twenty-first century Historical glossary Bibliography Index

The not-so-Great Ruaha and hidden histories of an environmental panic in Tanzania

Water is one of the world's most contested resources, and Africa's river basins are no exception. In December 1993 the Great Ruaha River upstream of Tanzania's Mtera Dam stopped flowing for the first time in living memory. This became a matter of national concern in 1995 when electricity shortages and rationing in Dar es Salaam were blamed by the national power supply company (TANESCO) on the continuing drying-up of the Great Ruaha. Since then different institutions and interest groups have sought to explain the river's increasing seasonality, focusing on resource use in and around its immediate source, the Usangu wetland, and laying the blame on different groups of resource users. In 1998 the core of the wetland (Ihefu) was gazetted as part of a new game reserve, and fishermen and livestock keepers were forcibly removed. Increasing government concern over power shortages culminated in the mass expulsion in 2006–07 of livestock keepers and their cattle from Usangu and Mbarali District, large parts of which were to be incorporated in an expanded Ruaha National Park. This was the largest eviction of its kind in recent Tanzanian history, widely condemned by NGOs and in the national and international media. This article examines in detail the development of the environmental panic and events which led to this eviction, highlighting the behind-the-scenes role played by actors and interests in the public and private sectors in fostering the panic and its controversial outcome.

The Two River Narratives in Heart of Darkness

Joseph Conrad informed his readers that 'Youth' is a feat of memory and a record of experience, while 'Heart of Darkness' is experience (. . .);butitisexperiencepushedalittle(andaverylittle)beyondtheac- tual facts of (Author's,Youthxi). The facts of case we be- lieve are these: Conrad composed Heart of Darkness by stitching together two rather different stories.At point in narrative where Charlie Marlow begins his voyage upriver to meet Kurtz, Conrad pushed novel beyond his own remembered experiences by imagin- ing Marlow journeying to a particular region deep within heart of Africa to which author had never traveled. The narrative then be- comes both stylistically and thematically different from what Marlow tells us he experienced during hisfirst three months in Africa, since horror Kurtz confronts constitutes part of a rather different tale having no necessary connection to exploitation of Congo depicted ear- lierinthenovella. Readers have repeatedly sought to relate Marlow's upriver voyage to facts of Conrad's experience. We will challenge that approach by distinguishing Congo on which Conrad voyaged from another river inAfrica that he visited, never traveled on, but which he imagined to be theonethattookMarlowintotheheartofdarkness(Heart95).Only then can we begin to distinguish major themes within novella that readers have tended to confuse. Countless critics have contended that Heart of Darkness confronts evils of imperialism, but what ConradactuallywitnessedonhisjourneyuptheCongoandwhatheat- tackedinhisnovellawasnotwhatheunderstoodtobetheevilsofimpe- rialism. The following article should clarify many of these issues by providingreadersforthefirsttimewiththecorrectandmostrelevantin- formationregardingMarlow'svoyage. Seeking to disentangle fact from fiction in actual journey up- river, Norman Sherry has shown in considerable detail how Conrad apparently pushed his experience quite a lot: journey Conrad made on the Roi des Belges was very different (from Marlow's)(. . .). The

Patterns of alien plant distribution at multiple spatial scales in a large national park: implications for ecology, management and monitoring

ABSTRACTAim Spatial scale is critical for understanding and managing biological invasions. In providing direction to managing alien plant invasions, much emphasis is placed on collecting spatially explicit data. However, insufficient thought is often given to how the data are to be used, frequently resulting in the incompatibility of the data for different uses. This paper explores the role of spatial scale in interpreting, managing and monitoring alien plant invasions in a large protected area.Location Kruger National Park, South Africa.Methods Using 27,000 spatially‐explicit records of invasive alien plants for the Kruger National Park (&gt; 20,000 km2) we assessed alien plant species richness per cell at nine different scales of resolution.Results When assessing the patterns of alien plants at the various scales of resolution, almost identical results are obtained when working at scales of quarter‐degree grids and quaternary watersheds (the fourth level category in South Africa's river basin classification system). Likewise, insights gained from working at resolutions of 0.1–0.5 km and 1–5 km are similar. At a scale of 0.1 × 0.1 km cells, only 0.4% of the Kruger National Park is invaded, whereas &gt; 90% of the park is invaded when mapped at the quarter‐degree cell resolution.Main conclusions Selecting the appropriate scale of resolution is crucial when evaluating the distribution and abundance of alien plant invasions, understanding ecological processes, and operationalizing management applications and monitoring strategies. Quarter‐degree grids and quaternary watersheds are most useful at a regional or national scale. Grid cells of 1 to 25 km2 are generally useful for establishing priorities for and planning management interventions. Fine‐scale data are useful for informing management in areas which are small in extent; they also provide the detail appropriate for assessing patterns and rates of invasion.

Allopatric differentiation in the Marcusenius macrolepidotus species complex in southern and eastern Africa: the resurrection of M. pongolensis and M. angolensis, and the description of two new species (Mormyridae, Teleostei)

We critically compared local populations of the bulldog fish, Marcusenius macrolepidotus (Peters 1852), from different watersheds, from the furthest south (28° South, South Africa) to the Equator in Kenya. We ascertained allopatric differentiation from topotypical M. macrolepidotus from the Lower Zambezi River (Mozambique) in morphology, electric organ discharges, and molecular genetics for: (1) samples from the Okavango and Upper Zambezi Systems (Botswana and Namibia), (2) samples from South Africa's rivers draining into the Indian Ocean, and (3) samples from the East African Tana River (Kenya). Significant genetic distances in the mitochondrial cytochrome b gene and differing ISSR‐PCR profiles corroborate differentiation between the four taxa. We resurrect M. pongolensis (Fowler, 1934) for South Africa (sample 2), and M. angolensis (Boulenger, 1905) for the Quanza River/Angola. We recognize M. altisambesi sp. n. for the Upper Zambezi/Okavango specimens (sample 1), and M. devosi sp. n. for those from Kenya (sample 3).

Ian Parker. Jua Kali's Voyage on the Jade Sea. Moray, Scotland: Librario Publishing Ltd., 2004. xi + 228 pp. Maps. Photographs. Notes. Index. Appendix. £21.00. Cloth. - Kira Salak. The Cruelest Journey: 600 Miles to Timbuktu. Washington, D.C.: National Geographic, 2005. x + 230 pp. Map. $26.00. Cloth.

Ian Parker. Jua Kali's Voyage on the Jade Sea. Moray, Scotland: Librario Publishing Ltd., 2004. xi + 228 pp. Maps. Photographs. Notes. Index. Appendix. £21.00. Cloth. - Kira Salak. The Cruelest Journey: 600 Miles to Timbuktu. Washington, D.C.: National Geographic, 2005. x + 230 pp. Map. $26.00. Cloth. - Volume 50 Issue 1

THE DEVELOPMENT OF A GEOMORPHOLOGICAL CLASSIFICATION SYSTEM FOR THE LONGITUDINAL ZONATION OF SOUTH AFRICAN RIVERS

ABSTRACT The recognition of the Reserve by the new South African Water Law poses new challenges for river scientists. The ecological water requirement or environmental flow is recognised by that part of the Reserve known as the ecological Reserve. If the ecological Reserve is to be implemented, it must first be defined and quantified for all river systems subject to water related developments. Standard procedures are being developed through the Resource Directed Measures (RDM) of the Department of Water Affairs and Forestry while monitoring the health of South Africa's rivers is taking place through the National River Health Programme (NRHP). Cost effective methods of developing spatial frameworks for both the RDM and NRHP are required. Concepts of longitudinal river zonation were developed by river ecologists in the 1960s and 1970s to assist in the classification of ecologically uniform stretches of rivers. This paper reviews the different zonation concepts and presents a geomorphological classification of South African river zones that is being applied to the RDM and NRHP. The classification is tested on three rivers, the Sabie, Buffalo and Olifants.

Simple Words and Fuzzy Zones: Early Directions for Temporary River Research in South Africa

/ Although a large proportion of South Africa's rivers are nonperennial, ecological research into these systems has only recently been initiated. Consequently, we have little verified information about the ecological functioning of these rivers or knowledge of how best to manage them. High water demands in a semiarid region results in the flow of most perennial rivers being altered from permanent to temporary in sections, through impoundment, land-use changes, abstraction, etc. Conversely, sections of many temporary rivers are altered to perennial as a result of interbasin transfers or may be exploited for surface water. Effective and appropriate management of these modifications must be based on sound scientific information, which requires intensified, directed research. We anticipate that temporary river research in South Africa will, of necessity, be driven primarily by short-term collaborative efforts and secondarily by long-term ecological studies. At the outset, a simple conceptual framework is required to encourage an appreciation of current views of the spatial and temporal dynamics of nonperennial rivers and of the variability and unpredictability that characterize these systems. We adopt the view that perennial and episodic/ephemeral rivers represent either end of a continuum, separated by a suite of intermediate flow regimes. A conceptual diagram of this continuum is presented. In the absence of a functional classification for temporary rivers, a descriptive terminology has been systematically devised in an attempt to standardize definition of the different types of river regimes encountered in the country. Present terminology lacks structure and commonly accepted working definitions. KEY WORDS: Temporary rivers; Intermittent rivers; Continuum; Terminology; Classification; Ecosystem management; South Africa

The African experience with river basin development

The aim of this paper is, first, to examine the record to date for river basin development in tropical Africa; and second, to examine in more detail the role and performance of institutions in this record of African river basin development. The experience of institutions with river basin development are assessed against outcomes ‐ namely, the extent to which the resources of Africa's river basins have actually been developed in recent years and the role that institutions have played in that development.

Utilising South Africa's largest river: The physiographic background to the Orange River scheme

The Orange River, with an average annual runoff of 11 500 million m3, is the largest among South Africa's rivers, drains 48% of the total area of the country and provides for 22% of the total South African downflow. Not only does the average annual precipitation of the drainage basin vary from 2 000 mm in the upper reaches to 40 mm at the river's mouth in the Atlantic, but large deviations from the average are the rule rather than the exception over most of the area. The correspondingly low reliability in the discharge of the Orange master stream is demonstrated by a 0,6 coefficient of variability. For utilising the river's water efficiently, periodic and seasonal runoff deficits may be overcome by building large storage dams. This is the purpose of the H.F. Verwoerd Dam, near the confluence of the Caledon and the Orange Rivers, and the P.K. le Roux Dam 130 km lower downstream. They form part of the R490 million (1974 estimate) Orange River Project by which water is stored and distributed in canals and tunnels (one 82 km long) reaching beyond the basin boundaries to Bloemfontein in the north and Port Elizabeth in the south. The implementation of the Orange River and Tugela-Vaal Schemes shifted the spatial focus of water development upstream along the Orange, Caledon and Vaal Rivers towards the plateau blocks of Lesotho.