Browsing by Subject "Southern Africa"
Now showing items 1-20 of 20
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Mnjama, N. (Library Management; Emerald Group Publishing Ltd.; www.emeraldinsight.com/researchregister; www.emeraldinsight.com/0143-5124.htm, NaN, 2005)[more][less]
Abstract: This article seeks to answer one basic question: “Are archival institutions in the Eastern and Southern African region developing, stagnating or receding backwards?” Design/methodology/approach – This article reviews the state of archives and records management in the Eastern and Southern African region. It argues that many archival services in the region have gone through a period of retardation and are in dire need of revitalization. Findings – The article indicates that the challenges of managing electronic records are enormous and that unless measures are taken the region stands to lose much of its valuable historical and cultural heritage. Originality/value – The article suggests various ways of revitalizing archival services in the Eastern and Southern African region. URI: http://hdl.handle.net/10311/57 Files in this item: 2
license.txt (1.998Kb)mnjama_archival_landscape.pdf (4.734Mb) -
Mapeo, R.B.M.; Armstrong, R.A.; Kampunzu, A.B.; Modisi, M.P.; Ramokate, L.V.; Modie, B.N.J. (Elsevier www.elsevier.com/locate/epsl, NaN, 2006)[more][less]
Abstract: The Segwagwa Group of southeastern Botswana, a correlate of the Pretoria Group of the Transvaal Supergroup of South Africa, consists of a major sequence of siliciclastic sedimentary rocks, minor carbonates and basaltic to andesitic lavas and tuffs straddling the Western and Central Domains of the Kaapvaal Craton. The Segwagwa Group unconformably overlies the Taupone Dolomite Group, a correlative of the South African Chuniespoort/Ghaap Groups of the Transvaal Supergroup. SHRIMP U–Pb analyses of 123 detrital zircons from the top, middle and bottom of the Segwagwa Group sedimentary rocks include 96 concordant to nearconcordant zircons defining three main age groups: >3.0–2.9 Ga (n=12), 2.8–2.5 Ga (n=27) and 2.45–2.20 Ga (n=57). The ≥2.90 Ga zircons were sourced from granitoids emplaced before and around 2915±12 Ma and are related to the amalgamation of the Western, Northern and Central Domains of the Kaapvaal Craton. Concordant zircons with a mean age of 2781±8 Ma originate from the Gaborone Igneous Complex. The detrital zircons in the range 2.7–2.5 Ga were likely sourced from the Kalahari continental fragment made up of the Kaapvaal Craton, Limpopo Belt and the Zimbabwe Craton, specifically from the Limpopo Belt and/or the Zimbabwe Craton where igneous rocks in this age range are widespread. The igneous sources for the Palaeoproterozoic (ca. 2.45–2.20 Ga) zircons are difficult to identify since igneous rocks in that age are not widely known or documented by reliable dates in the Kalahari Craton. The youngest zircons of ca. 2.2 Ga occur in all the sandstones and form the main group (N90%) in the sample from the top of the Segwagwa Group. The youngest detrital zircon of 2193±20 Ma sets the maximum time of deposition of the Segwagwa Group. Published data suggest that the minimum deposition age of Chuniespoort/Ghaap Group sedimentary rocks is 2431±31 Ma [D.R. Nelson, Compilation of SHRIMP U-Pb zircon Geochronological Data, 1996 Record 1997/2, pp. 189, Western Australia Geological Survey, 1997.]. Therefore, the unconformity between the Lower and Upper Transvaal represents a ∼200 Ma hiatus, and the lithostratigraphic units on the two sides of the unconformity should not be grouped in the same supergroup. Detrital zircon ages suggest that the time of deposition of the Segwagwa/Pretoria Group which ranges from ca. 2.40 to 2.20 Ga is coeval with the Palaeoproterozoic global glacial deposits in North America, Australia and Fennoscandia; and with sedimentary rocks from the Palaeoproterozoic Magondi Belt. Therefore, the Segwagwa/Pretoria Group and the Magondi metasedimentary succession were deposited during the first global glacial period, are possibly related to the same geodynamic cycle, and should be part of the same supergroup. URI: http://hdl.handle.net/10311/742 Files in this item: 1
Mapeo2006Transvaal Groups.pdf (1.993Mb) -
Fako, T.T. (Taylor & Francis, www.taylorandfrancis.com, NaN, 1997)[more][less]
Abstract: The 1990s began with a commitment to children through the adoption, by the United Nations General Assembly, of the Convention on the Rights of the Child. This Convention set the minimum standards of protection for children's survival, health and education; protection against exploitation at work; protection against the degradations of war; and protection against physical and sexual abuse. By 20th July, 1994, 163 countries had ratified the Convention and 11 other countries had signed but not yet ratified the convention (World Health Organization, 1994:1). URI: http://hdl.handle.net/10311/1119 Files in this item: 1
Fako_ST_1997.pdf (535.5Kb) -
Alemaw, B.F.; Chaoka, T.R. (Pergamon www.elsevier.com/locate/pce, NaN, 2003)[more][less]
Abstract: A distributed GIS-based hydrological model is developed using GIS and computational hydrology techniques. The model is based on water balance consideration of the surface and subsurface processes. The surface water balance processes include precipitation infiltration, overland runoff, evapo-transpiration and canopy surface interception losses on daily time steps; The subsurface process considers soil moisture accounting on a monthly basis. The model was used to estimate generated runoff from matrix of specific geo-referenced grids representing Southern Africa. All regional and seasonal dispensation of water balances have been based on standard GIS formats for storage, spatial display and interpretation of results. Considering the 1961–1990 climatic period, we have mapped the regional variation of the mean annual soil moisture (SM), actual evapo-transpiration (AET), and generated runoff (ROF) across Southern Africa or known as the SADC region. The model estimates the mean SM of the region to be about 148 mm/year. There is a wide spatial range in the distribution of SM over the region due to the fact that the absolute soil moisture is dependent on the water retention properties of the soils considered across the region. The model prediction of the mean annual AET in the region reaches a maximum of 1500 mm, with mean 420 mm. The mean annual generated runoff from the land catchment in the region is about 151 mm/year although there is a significant inter-regional variation among the SADC countries, which is a function of the variation in the vegetation cover, soil and climate variation. Lower runoff regimes are dominant in arid areas in Botswana, Namibia and south-western part of the Republic of South Africa. Higher runoff regimes are the Northern and Western Tanzania, along the east coastal portions of Mozambique, central Mozambique, western Zambia and Malawi. URI: http://hdl.handle.net/10311/494 Files in this item: 1
ALEMAW2003CONTINENTAL SCALE.pdf (623.4Kb) -
Alemaw, B.F.; Chaoka, T.R. (Pergamon www.elsevier.com/locate/pce, NaN, 2003)[more][less]
Abstract: A distributed GIS-based hydrological model is developed using GIS and computational hydrology techniques. The model is based on water balance consideration of the surface and subsurface processes. The surface water balance processes include precipitation infiltration, overland runoff, evapo-transpiration and canopy surface interception losses on daily time steps; The subsurface process considers soil moisture accounting on a monthly basis. The model was used to estimate generated runoff from matrix of specific geo-referenced grids representing Southern Africa. All regional and seasonal dispensation of water balances have been based on standard GIS formats for storage, spatial display and interpretation of results. Considering the 1961–1990 climatic period, we have mapped the regional variation of the mean annual soil moisture (SM), actual evapo-transpiration (AET), and generated runoff (ROF) across Southern Africa or known as the SADC region. The model estimates the mean SM of the region to be about 148 mm/year. There is a wide spatial range in the distribution of SM over the region due to the fact that the absolute soil moisture is dependent on the water retention properties of the soils considered across the region. The model prediction of the mean annual AET in the region reaches a maximum of 1500 mm, with mean 420 mm. The mean annual generated runoff from the land catchment in the region is about 151 mm/year although there is a significant inter-regional variation among the SADC countries, which is a function of the variation in the vegetation cover, soil and climate variation. Lower runoff regimes are dominant in arid areas in Botswana, Namibia and south-western part of the Republic of South Africa. Higher runoff regimes are the Northern and Western Tanzania, along the east coastal portions of Mozambique, central Mozambique, western Zambia and Malawi. URI: http://hdl.handle.net/10311/492 Files in this item: 1
ALEMAW2003CONTINENTAL SCALE.pdf (623.4Kb) -
Ojedokun, A.A.; Lumande, E. (Sage Publications, http://www.sagepublications.com, NaN, 2005)[more][less]
Abstract: The development of cooperative electronic networks and consortia by academic libraries in Southern Africa allows them to provide seamless access to electronic information resources while sharing the cost of access. URI: http://hdl.handle.net/10311/925 Files in this item: 1
Ojedokun_ID_2005.pdf (858.6Kb) -
Haron, M. (Journal of Muslim Minority Affairs; Carfax Publishing; Taylor & Francis; http://www.tandf.co.uk/journals/titles/13602004.asp, August NaN, 2005)[more][less]
Abstract: This paper provides a brief survey of the contemporary da'wah movements and Sufi orders (tariqah) that have redefined and reformulated some of the social institutions among the Muslim community in southern Africa. After a theoretical discussion of the definition of movements and orders, the paper provides a brief overview of Islam's presence in contemporary southern Africa. This is followed by a historical review of the various Sufi tariqahs and Muslim movements in the region, focusing on the Tabligh Jama'at at and including the Chistiyyah, Murabitun, Qadriyyah, Alawiyyah and Naqshbandi tariqahs. In the final section of the paper comparisons are made between the growth of da'wah movements and Sufi tariqahs and the reasons for their relative influences and successes are analysed. URI: http://hdl.handle.net/10311/34 Files in this item: 2
haron_jmma_2005.pdf (2.699Mb)license.txt (1.998Kb) -
Mnjama, N. (SAGE Publications, http://idv.sagepub.com/, NaN, 2006)[more][less]
Abstract: Discusses the problems associated with managing semi-current and non-current in many archival institutions in eastern and southern Africa. The article seeks to answer some basic questions such as: Why do archival institutions in the region have backlog accumulations? What is the level of awareness of the problems associated with backlog accumulations? What is the capacity of archives to handle records created by governments? What mechanisms need to be put in place to avoid backlog accumulations ever becoming a problem again in the region? Finally the article proposes a strategy for dealing with backlog accumulations. URI: http://hdl.handle.net/10311/600 Files in this item: 1
Mnjama_ID_2006.pdf (1.317Mb) -
Heinl, M.; Frost, P.; Vanderpost, C.; Sliva, J. (Elsevier; http://www.elsevier.com/wps/find/journaldescription.cws_home/622855/description#description, May 8, 2006)[more][less]
Abstract: Satellite imagery derived fire history data for the southern Okavango Delta, Botswana from 1989 to 2003 were used to analyse the temporal and spatial distribution of fires and to assess changes in fire activity. Maximum fire activity was encountered for 1997 with 24.1% of the study area burned. The annual extent of the burned area fluctuated considerably, but there appeared to be a regular oscillation apparently induced by floodplain fires. The main fire activity on drylands is in September at the end of the dry season, while most floodplains burn earlier in the year. Both burning of floodplains and drylands appear to peak prior to floods and rainfall-events, respectively. Areas with highest fire frequency were outlined and spatial analyses showed that fires on the drylands are largely due to burning of adjacent floodplains. The floodplains were therefore identified as the centres of fire activity, being the regions with the highest fire frequency and serving as source of fires spreading into drylands. Floodplains showed higher fire frequencies compared to drylands, but no increase in fire activity was detected over the study period for both floodplains and drylands. Description: The study was part of the project 'Fire regime and vegetation response in the Okavango Delta, Botswana' funded by the Volkswagen Foundation, Germany and carried out by the Chair of Vegetation Ecology, Technische Universitaet Muenchen, Germany in collaboration with the Harry Oppenheimer Okavango Research Center (HOORC, University of Botswana) and University of Pretoria, South Africa. Financial support was also given by Conservation International Botswana and the German Academic Exchange Service (DAAD). URI: http://hdl.handle.net/10311/151 Files in this item: 2
heinl_j_arid_env.pdf (392.9Kb)license.txt (1.998Kb) -
Haron, M. (Faculty of Theology, University of Stellenbosch, http://academic.sun.ac.za/tsv/Scriptura/scriptura.htm, NaN, 2006)[more][less]
Abstract: Southern Africa's Muslim minorities have been growing at a steady pace through procreation, conversion and migration. These Muslim communities have rooted and embedded themselves onto the Southern African soil and have contributed in varied ways to the respective countries where they reside and live. Apart from South Africa's well documented Muslim community, very little attention has been given by scholars to the Muslim communities in its neighbouring states. When one surveys the region, it becomes evident that nothing substantial has been written about the Muslims in Namibia, Swaziland and Lesotho except for a few popular journalistic articles, and that few attempts have been made by scholars to write about the Muslim communities in Zimbabwe, Mozambique and Botswana. This article will therefore try to look at the last mentioned country with specific focus on the Gaborone Muslim community. This article complements the academic studies that have been produced in 1989 and 1998/2000 respectively. This article mainly focuses itself upon the contemporary developments that have taken place in Botswana's capital city where most of the Muslims reside and work. It intends to pinpoint, describe and briefly analyse all the major role players and institutions that are around and that have contributed towards creating a unique Gaborone Muslim community. URI: http://hdl.handle.net/10311/150 Files in this item: 2
haron_gaborone_muslimcommunity2006.pdf (214.9Kb)license.txt (1.998Kb) -
Ranganai, R.T.; Kampunzu, A.B.; Atekwana, E.A.; Paya, B.K.; King, J.G.; Koosimile, D.I.; Stettler, E.H. (Royal Astronomical Society. http://www.wiley.com/bw/journal.asp?ref=0956-540X&site=1, NaN, 2002)[more][less]
Abstract: The Limpopo Belt of southern Africa is a Neoarchean orogenic belt located between two older Archean provinces, the Zimbabwe craton to the north and the Kaapvaal craton to the south. Previous studies considered the Limpopo Belt to be a linearly trending east-northeast belt with a width of ~250 km and ~600 km long. We provide evidence from gravity data constrained by seismic and geochronologic data suggesting that the Limpopo Belt is much larger than previously assumed and includes the Shashe Belt in Botswana, thus defining a southward convex orogenic arc sandwiched between the two cratons. The 2 Ga Magondi orogenic belt truncates the Limpopo–Shahse Belt to the west. The northern marginal, central and southern marginal tectonic zones define a single gravity anomaly on upward continued maps, indicating that they had the same exhumation history. This interpretation requires a tectonic model involving convergence between the Kaapvaal and Zimbabwe cratons during a Neoarchean orogeny that preserved the thick cratonic keel that has been imaged in tomographic models. URI: http://hdl.handle.net/10311/326 Files in this item: 1
Ranganai_GJI_2002.pdf (1.361Mb) -
Molefi, R.K.K. (University of Botswana, Research and Development Unit / http://digital.lib.msu.edu/projects/africanjournals/browse.cfm?colid=12, NaN, 2001)[more][less]
Abstract: This paper examines the responses of colonial governments to outbreaks of bubonic plague in the interior, particularly that of the Bechuanaland Protectorate (Botswana) administration. Bubonic plague first reached Southern Africa through the seaports of Cape Town, Port Elizabeth, East London, and Durban in 1900 at the height of the Anglo-Boer war of 1899- 1902. The dread disease found Southern Africa's ports, harbours and railway stations bursting at the seams with wartime commerce, and with an influx of refugees from the interior and large numbers of migrant labourers. From the ports, the plague spread to towns close to railway stations and finally into the interior where it caused havoc for the political economy of rural Southern Africa. Bubonic plague normally spreads as a disease among rodent populations living in the vicinity of human habitation. Fleas from dead rats if unable to find another rodent host begin to infest people instead. Bubonic plague became endemic in Southern Africa, and natural reservoirs of the malady still exist in the region. URI: http://hdl.handle.net/10311/736 Files in this item: 1
Molefi_PBJAS_2001.pdf (1.105Mb) -
Morapedi, W.G. (Routledge (Taylor and Francis) www.routledge.com, NaN, 2007)[more][less]
Abstract: For the last two decades, Botswana has had a reputation as a ‘country of immigration’, based on the large-scale import of skilled expatriates from Africa, Asia, and the West. This policy has been accompanied by a general acceptance, and even openness, on the part of Batswana towards non-citizens. In the late 1990s, however, these attitudes began to change, with intolerance towards non-citizens growing in a country where it was unknown only a few years earlier. (Crush 2003:1-2) The underlying reason for the growth in intolerance seems to be related to actual changes in immigration patterns in Botswana. The economic and political problems in Zimbabwe in particular have led to a significant increase in unauthorised migration to and through Botswana. The Botswana authorities have become considerably more active in arresting and deporting unauthorised migrants. Further adding to the visibility of the issue, the media and politicians have begun to identify the presence of ‘illegal immigrants’ as a problem. URI: http://hdl.handle.net/10311/723 Files in this item: 1
Morapedi_JCAS_2007.pdf (1.902Mb) -
Voss, J.; Sukati, N.; Seboni, N.; Makoae, L.; Moleko, M.; Human, S.; Molosiwa, K.; Holzemer, W. (Elsevier; http://www.elsevier.com/wps/find/journaldescription.cws_home/704632/description#description; Association of Nurses in AIDS Care. http://www.nursesinaidscare.org/i4a/pages/index.cfm?pageid=3277, NaN, 2007)[more][less]
Abstract: HIV-related fatigue is a debilitating and disabling symptom that persists for months and years. In 743 HIV/AIDS patients from Southern Africa, the authors found ratings of HIV-related fatigue to be highly prevalent. The authors conducted a secondary data analysis within the theoretical context of the University of California, San Francisco Symptom Management Model. The analysis focused on 538 patients who reported fatigue to investigate correlates and predictors of fatigue severity in relationship to demographic and HIV/AIDS illness indicators, as well as HIV-specific physical and psychological symptoms. A hierarchical regression model explored the contributions of those five blocks on fatigue severity. Of the 47% of the total variance in fatigue severity, a combination of variables within the health and illness block (6%), the physical symptoms block (7%) and the psychological symptom block (2%) contributed significantly to the increase in fatigue severity scores. Fatigue severity in Southern Africa was moderate, and the factors contributing to the perceived fatigue were most likely related to symptoms of acute HIV disease (such as fever and gastrointestinal problems). In conclusion, fatigue severity is less impacted by demographic or environmental variables but much more by co-occurring symptoms and HIV disease severity. The results of this study imply the need for more research to understand if improvements in water quality and access to food would prevent infection and diarrhea and whether sufficient access to antiretroviral treatments to manage the HIV infection would improve fatigue and co-occurring symptom profiles. URI: http://hdl.handle.net/10311/263 Files in this item: 2
license.txt (1.998Kb)Symptom Burden of Fatigue.pdf (5.279Mb) -
Voss, J.G.; Sukati, N.A.; Seboni, N.M.; Makoae, L.N.; Moleko, M.; Human, S.; Molosiwa, K.; Holzemer, W.L. (Association of Nurses in AIDS Care. http://www.elsevier.com/wps/find/journaldescription.cws_home/704632/description#description, NaN, 2005)[more][less]
Abstract: HIV-related fatigue is a debilitating and disabling symptom that persists for months and years. In 743 HIV/AIDS patients from Southern Africa, the authors found ratings of HIV-related fatigue to be highly prevalent. The authors conducted a secondary data analysis within the theoretical context of the University of California, San Francisco Symptom Management Model. The analysis focused on 538 patients who reported fatigue to investigate correlates and predictors of fatigue severity in relationship to demographic and HIV/AIDS illness indicators, as well as HIV-specific physical and psychological symptoms. A hierarchical regression model explored the contributions of those five blocks on fatigue severity. Of the 47% of the total variance in fatigue severity, a combination of variables within the health and illness block (6%), the physical symptoms block (7%) and the psychological symptom block (2%) contributed significantly to the increase in fatigue severity scores. Fatigue severity in Southern Africa was moderate, and the factors contributing to the perceived fatigue were most likely related to symptoms of acute HIV disease (such as fever and gastrointestinal problems). In conclusion, fatigue severity is less impacted by demographic or environmental variables but much more by co-occurring symptoms and HIV disease severity. The results of this study imply the need for more research to understand if improvements in water quality and access to food would prevent infection and diarrhea and whether sufficient access to antiretroviral treatments to manage the HIV infection would improve fatigue and co-occurring symptom profiles. URI: http://hdl.handle.net/10311/538 Files in this item: 1
The symptom experience.pdf (1.131Mb) -
Makoae, L.C.; Seboni, N.M.; Molosiwa, K.; Moleko, M.; Human, S.; Sukati, N.A.; Holzemer, W.L. (Association of Nurses in AIDS Care. http://www.elsevier.com/wps/find/journaldescription.cws_home/704632/authorinstructions, NaN, 2005)[more][less]
Abstract: This study describes the symptom experience of 743 men and women living with HIV/AIDS in Botswana, Lesotho, South Africa, and Swaziland. Data were obtained in 2002 by using a cross-sectional design. A survey of participants included 17 sociodemographic items and the 64-item Revised Sign and Symptom Checklist for Persons with HIV Disease. Results indicate a strong correlation between the frequency of reported symptoms and their intensity (r .84, p .00). Participants who reported having enough money for daily expenses also reported significantly fewer symptoms. There were no significant differences in symptom frequency between men and women or by location of residence. The study showed a complex picture of HIV-related symptoms in all four countries. Because of the high levels of symptoms reported, the results imply an urgent need for effective home- and community-based symptom management in countries where antiretroviral therapy is unavailable to help patients and their families manage and control AIDS symptoms and improve quality of life. URI: http://hdl.handle.net/10311/558 Files in this item: 1
Symptom experience.pdf (1.693Mb) -
Makgala, C.J. (Cambridge University Press, NaN, 2004)[more][less]
Abstract: This essay examines, through taxation, the relationship between British colonial administrators, Tswana Dikgosi (chiefs) and their subjects in the Bechuanaland Protectorate from 1899 to 1957. It argues that since Bechuanaland became a British territory through negotiations the Tswana rulers were able to protect their interests aggressively but with little risk of being deposed. Moreover, the Tswana succession system by primogeniture worked to their advantage whenever the British sought to replace them. Taxation was one arena where this was demonstrated. Although consultation between the Dikgosi, their subjects and the British was common, subordinate tribes sometimes fared badly under Tswana rule. URI: http://hdl.handle.net/10311/512 Files in this item: 1
makgala_JAH_2004.pdf (198.6Kb) -
Rwelamila, P. D.; Talukhaba, A .A.; Ngowi, A.B. (Emerald http://www.emeraldinsight.com, NaN, 1999)[more][less]
Abstract: The lack of 'ubuntu'(African group solidarity) between project stakeholders in the Southern Africa Development Community (SADC) public building sector has been surrounded by controversy and strongly held opinions. The work reported in this paper attempts to indicate some salient issues affecting the relationshps between project stakeholders. The Botswana public building sector is used as a main case study and follwo-up studies are carried out involving another eight SADC countries. The paper addresses two propositions.First, that the lack of 'ubuntu' between project stakeholders is primarily due to an inappropriate project organizational structure.Second, that a default traditional construction procurement system (TCPS) provides a poor relationship management system. Information is obtained on the research areas through questionnaires to confirm executives, contract managers, site managers, trade foremen and skilled tradeperson on the dominant procurement system used in Botswana. Furthermore, senior technical officers of Public Works Ministries of another eight SADC countries are interviewed as a follow-up to the Botswana study. The primary conclusion to be drawn is that the building procurement system purported to be in use in the SADC public building sector differs significantly from that recommended in the theory, resulting in poor relationships between project stakeholders. This is primarily due to the use of inappropriate building procurement systems. In general, the TCPS in the SADC public buiding sector is used as a 'default system.' This has led to a situation where project management is a 'firefighting' activity, where group solidarity between project stakeholders is out of reach. Salient steps are proposed with proviso that the SADC public building sector should establish appropriate methods of selecting building procurement systems as a prerequisite in formulating appropriate project organizational structures which will bring the spirit of real co-operation between project stakeholders towards project success. URI: http://hdl.handle.net/10311/612 Files in this item: 1
Rwelamila_ECAM_1999.pdf (1.580Mb) -
Black, F.J.; Bokhutlo, T.; Somoxa, A.; Maethamako, M.; Modisaemang, O.; Kemosedile, T.; Cobb-Adams, C.; Mosepele, K. (Elsevier, February 20, 2011)[more][less]
Abstract: Mercury is a neurotoxin and global pollutant, and wetlands and newly flooded areas are known to be sites of enhanced production of monomethylmercury, the form of mercury that is readily biomagnified in aquatic food chains to potentially toxic levels. The Okavango Delta in Botswana, Southern Africa, is the largest inland delta in the world and a wetland ecosystem that experiences dramatic annual flooding of large tracts of seasonal floodplains. The Delta was, therefore, expected to be home to high mercury levels in fish and to be an area where local subsistence fishing communities would be at substantial risk of mercury toxicity from fish consumption. Total mercury concentrations measured in 27 species of fish from the Okavango Delta averaged (mean±s.d., wet weight) 19±19 ng g−1 in non-piscivorous fish, and 59±53 ng g−1 in piscivorous fish. These mercury concentrations are similar to those reported for fish from lakes in other areas of tropical Africa, demonstrating that not all wetlands are sites of elevated mercury concentrations in biota. Even more intriguing is that concentrations of mercury in fish from across tropical Africa are systematically and substantially lower than those typically reported for fish from freshwater ecosystems elsewhere globally. The reasons for this apparent “African mercury anomaly” are unclear, but this finding poses a unique opportunity to improve our understanding of mercury's biogeochemical cycling in the environment. Mercury concentrations measured in human hair collected in subsistence fishing communities in the Okavango Delta were similarly low (0.21±0.22 μg g−1 dry weight) despite high levels of fish consumption, and reflect the low mercury concentrations in the fish here. URI: http://hdl.handle.net/10311/806 Files in this item: 1
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Black, F.J.; Bokhutlo, T.; Somoxa, A.; Maethamako, M.; Modisaemang, O.; Kemosedile, T.; Cobb-Adams, C.; Mosepele, K.; Chimbari, M. (Elsevier, NaN, 2011)[more][less]
Abstract: Mercury is a neurotoxin and global pollutant, and wetlands and newly flooded areas are known to be sites of enhanced production of monomethylmercury, the form of mercury that is readily biomagnified in aquatic food chains to potentially toxic levels. The Okavango Delta in Botswana, Southern Africa, is the largest inland delta in the world and a wetland ecosystem that experiences dramatic annual flooding of large tracts of seasonal floodplains. The Delta was, therefore, expected to be home to high mercury levels in fish and to be an area where local subsistence fishing communities would be at substantial risk of mercury toxicity from fish consumption. Total mercury concentrations measured in 27 species of fish from the Okavango Delta averaged (mean ± s.d., wet weight) 19 ± 19 ng g−1 in non-piscivorous fish, and 59 ± 53 ng g−1 in piscivorous fish. These mercury concentrations are similar to those reported for fish from lakes in other areas of tropical Africa, demonstrating that not all wetlands are sites of elevated mercury concentrations in biota. Even more intriguing is that concentrations of mercury in fish from across tropical Africa are systematically and substantially lower than those typically reported for fish from freshwater ecosystems elsewhere globally. The reasons for this apparent “African mercury anomaly” are unclear, but this finding poses a unique opportunity to improve our understanding of mercury's biogeochemical cycling in the environment.Mercury concentrations measured in human hair collected in subsistence fishing communities in the Okavango Delta were similarly low (0.21 ± 0.22 μg g−1 dry weight) despite high levels of fish consumption, and reflect the low mercury concentrations in the fish here. URI: http://hdl.handle.net/10311/782 Files in this item: 1
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