Metal concentrations in <i>Clarias gariepinus</i> and <i>Labeo umbratus</i> from the Olifants and Klein Olifants River, Mpumalanga, South Africa: zinc, copper, manganese, lead, chromium, nickel, aluminium and iron

Abstract

The upper catchment of the Olifants River, from its origin near Bethal to its confluence with the Wilge River, north of Witbank, and its tributaries are being subjected to increasing afforestation, mining, power generation, irrigation, domestic and industrial activities. These activities have a profound effect on the water quality. The major point sources of pollution in the study area include mines, industries and very importantly, combined sewage purification works that are located alongside the river. In addition to oxidizable material, these sources contain detergents, nutrients and metals. It was therefore necessary to determine the extent to which these activities affect the water quality of the system. The bioaccumulation of zinc (Zn), copper(Cu), manganese (Mn), lead (Pb), chromium (Cr), nickel (Ni), aluminium (Al) and iron (Fe) in the skin, muscle, liver and gill tissues of Clarias gariepinus and Labeo umbratus from the Upper Olifants River and Klein Olifants River was investigated over the period February 1994 to May 1995. The highest concentrations of these metals were found in the gill and liver tissues of both species, with lower concentrations in the skin and muscle tissues. Bioaccumulation patterns were found to vary according to the species of the fish, mainly according to their different feeding habits and the routes of metal uptake. It also varied as a function of the different localities. Accumulation was size specific, with higher concentrations of metals found in smaller fish. 434 Available on website http://www.wrc.org.za thermal power stations in the country are located (six of the eight). These power stations receive imported water, with the Komati-, Hendrina-, Arnot-and Duhva Power Stations receiving water from the Komati system and the Kriel-and Matla Power Stations from the Usutu system. The operating mines in this region comprise of 37 coal, 6 brick, 17 sand, 4 felsite and 7 clay mines. Irrigation is a major water use sector in the upper catchment and at the time of the study, 4 760 ha of land was irrigated. Seven towns are situated in the upper catchment. The Witbank/Middelburg complex is a major industrial area with smaller towns Davel, Kinross, Trichardt, Hendrina and Ogies. Several magisterial districts fall partly inside the catchment boundaries, namely Bethal, Belfast, Ermelo, Highveld Ridge, Middelburg and Witbank.

Impacts of alum residues from Morton Jaffray Water Works on water quality and fish, Harare, Zimbabwe

“…Kotze et al (1999) showed that bioaccumulation of metals in the fish studied occurred in the following order of decreasing intensity: liver>gills>skin>muscle. Further studies have confirmed these findings but in different fish such as Oreochromis niloticus, Cyprinus carpio and Labeo umbratus, Tilapia nilotica, Tilapia zilli, Clarias anguillaris, Protoptenus, Eutropius niloticus and Synodentis budgetti (Rashed, 2001;Coetzee et al, 2002;Vinodhini and Narayanan, 2008;Akan, 2009;Rauf et al, 2009). Rauf et al (2009) also obtained the same results as Kotze et al (1999) and established that the metal concentrations in the liver and gills were significantly different (p<0.01) and the minimum concentrations in the liver (4.26±1.57 and 6.23±1.14 µg/g) were higher than for gills (1.10±0.53 and 1.46±0.52 µg/g) for cadmium and chromium, respectively.…”

“…The gills, skeleton, kidneys, liver and muscles are the main target organs for Al toxicity in fish while the first three are the most susceptible organs to Al bioaccumulation in fish (Sharma, 2003). In contrast, Coetzee et al (2002) had shown that Al is accumulated mostly in the gill and liver tissue, followed by the muscle and skin tissues and that this uptake occurred primarily through the gills just as with any other heavy metal. These studies on Al accumulation agree that the gills are among the most susceptible to Al accumulation while the muscle accumulates the least but disagree in terms of the liver as Sharma reported that the liver and the muscle are the least susceptible.…”

“…No study has been carried out in the country concerning the residues from Morton Jaffray and their effect on fish as well as quality of the receiving water bodies. It has been shown elsewhere, however, that Al accumulates in sediments and water and that Al bioaccumulates in fish and its toxic effects in fish have been reported in literature (Abdullah et al, 1995;Giller and Malmquist, 1998;PBC, 1998;Coetzee et al, 2002;Sharma, 2003;Kegley et al, 2009) as well as in humans (Prolo et al, 2007).…”

“…Aluminium is one of the metals that forms insoluble precipitates in this pH range such that sediments will most likely contain significant amounts of this metal in surface waters. Abdullah et al (1995) and Coetzee et al (2002) observed that the concentrations of total Al significantly increased in the sediments compared to the water media. This basically shows the remarkable efficiency of the settling, adsorbing, scavenging and assimilating particles.…”

Bioaccumulation of aluminium and iron in the food chain of Lake Loskop, South Africa

“…These mines contribute large volumes of AMD to the upper reaches of the Olifant's River catchment upstream of Lake Loskop, which acts as a repository for pollutants from the upper catchment (Oberholster et al, 2010). To the authors' knowledge, only one earlier study has been carried out on the upper Olifant's River to determine metal bioaccumulation in fish, and which included Aluminium (Al) as a toxic agent of AMD (Coetzee et al, 2002). The authors found in their study that Zn, Cu, Mn, Pb, Cr, Ni, Al and Fe preferentially accumulated in the skin, muscle, liver and gill tissues of fish with the highest metal concentrations localized to the liver and gill tissues of Clarias gariepinus and Labeo Umbratus.…”