Pollution shapes the microbial communities in river water and sediments from the Olifants River catchment,South Africa

Archives of Microbiology - Human activities such as agriculture and mining are leading causes of water pollution worldwide. Individual contaminants are known to negatively affect microbial...     

Concentrations of zinc in Barbus marequensis from the lower Olifants River, Mpumalanga, South Africa

Zinc was detected in all the tissues examined, but in variable concentrations. The highest zinc concentrations were detected in the skin and ovaries. These zinc concentrations also differed significantly from the concentrations in the other tissues. The bioaccumulation pattern of zinc in the fish was determined as: skin >ovaries>liver>gills>vertebrae>testes>hindgut>foregut contents >kidney=foregut>hindgut contents>muscle>blood>fat>bile.Although significant differences (P<0.05) between localities were detected no clear trend as to where the highest bioaccumulation had occurred, could be established. Significant seasonal differences were detected, but it was not always the same tissue that indicates these seasonal differences. The zinc concentrations detected in the fish suggest no serious zinc pollution in the lower Olifants River. Zinc levels detected in some of the tissues might indicate chronic exposure, causing possible sub-lethal effects. However, this should be investigated before final conclusions can be made.     

Bioaccumulation of selected metals in the gill,liver and muscle tissue of rednose labeo Labeo rosae from two impoundments on the Olifants River,Limpopo river system,South Africa

Metal concentrations in the gill, muscle and liver tissues of Labeo rosae from two impoundments, Loskop and Flag Boshielo dams on the Olifants River, were evaluated in 2011 to detect patterns in metal associations between tissues and impoundments. Elevated concentrations of Ba, Zn, B, Al, Si and Fe, relative to a pristine site in the catchment, were found in the muscle, liver and gill tissues at both impoundments. Molybdenum concentrations were exceptionally high in all tissues at Loskop Dam and in liver at Flag Boshielo Dam. No definite pattern in the ratio metal concentrations within, or between, fish tissues was identified. The expected trend, liver > gills > muscle, was found at both impoundments, but was less prominent at Loskop Dam. Metal concentrations in muscle of Loskop Dam fish were significantly higher than in those at Flag Boshielo Dam. The inverse was true for liver. The long-term impact of elevated metal concentrations on fish health at both impoundments raises concern.     

Application of multivariate statistics and toxicity indices to evaluate the water quality suitability for fish of three rivers in the Kruger National Park,South Africa

The water quality of the Olifants, Letaba and Luvuvhu rivers within the Kruger National Park was assessed for their suitability to sustain fish populations. Since water quality assessments result in huge datasets, principal component analysis and an aquatic toxicity index (ATI) were employed to reduce these to more manageable indices. Water quality changed over time, with metal concentrations decreasing, and high flows resulted in increased concentrations of suspended metals. The ATI indicated that metals had no major effect on lowering index values in any of the rivers, and that these values were affected by turbidity in both the Olifants and Letaba rivers, whilst nutrients such as ammonium and orthophosphates negatively affected index scores in the Luvuvhu River. Water quality has improved from the 1990s to 2011.     

Phytoplankton Distribution in the Coastal Area Subject to the Impact with the Tiber River Outfall

The taxonomic composition and geographical distribution of phytoplankton in the coastal zone surrounding the River Tiber mouth were investigated in twelve surveys from April 1978 to September 1979. Ninety phytoplankton species were identified from 168 samples. Diatoms were clearly the dominating species, accounting for more than 95 per cent of total phytoplankton.— Principal Component Analysis was utilized to analyse the total information obtained.—The direct impact on the coastal environment of River Tiber water and its considerable nutrient load were seen as providing a permanent potential for the development of less structured phytoplankton communities. Heterogeneity of local hydrological conditions and fluctuations in the river's impact, lead to a virtually constant instability in the neritic environment near the Tiber River outfall.     

Fractionation,mobility and multivariate statistical evaluation of metals in marine sediments of Cape Town Harbour,South Africa

Abstract

Distribution of possible chemical forms of Al, Si, Sn, Pb, Zn, Fe, Hg, Cd and Cu in marine sediments of Cape Town harbour was investigated using a modified Tessier’s sequential extraction procedure and ICP-MS and ICP-AES for heavy metals determination. The mean fractions for all metals at all locations were: 1.5–7196 mg kg^-1 for Si, 7.79–7266 mg kg^-1 for Al, 161-639 mg kg^-1 for Cu, 19–41978 mg kg^-1 for Fe, 2.83–5864 mg kg^-1 for Zn, 1.45–13.26 mg kg^-1for Cd, 9.87–223 mg kg^-1 for Sn, 11.98-979 mg kg^-1 for Pb and 0.13–5.93 mg kg^-1 for Hg. Si, Al and Zn were mostly associated with Fe–Mn oxides, whereas Sn and Hg were mainly bound to residual and organic matter. Pb existed mainly in the residual and iron/manganese oxide phases while Cd was evenly distributed in all the five phases. The loading plots of heavy metals bound to the various chemical forms, as well as Pearson correlation coefficients, enabled the determination binding relationship. Pb, Sn and Hg exhibited similar binding behaviour which indicated an anthropogenic point source from wastes from the ship maintenance workshop, and the presence of Sn in the organic phase can be identified with the use of anti-fouling paints at the harbour, whereas Al, Fe, Si, Cu and Zn would probably be of natural origin. Lastly Cd probably came from a diffuse pollution sources in the harbour due to its unique binding characteristic. The mobility of heavy metals varied depending on location and the heavy metal type. The mobility of metals followed the order: Si > Zn > Fe > Cu> Al> Cd> Pb > Sn > Hg. The high percentage of Cd and Pb in the bioavailable forms suggested the need to keep close surveillance on these metals because of their high toxicity.     

Heavy metal contamination of water and fish in peri-urban dams around Bulawayo,Zimbabwe

Urban effluents are significant sources of heavy metal pollution in fresh water. Metal contamination in dams around the city of Bulawayo, Zimbabwe, were monitored during October 2014 to assess ecological and public health risks. Heavy metals were measured in water, sediment and fish in dams located downstream of effluent discharge zones in Bulawayo and were compared to those in a pristine upstream dam. Water conductivity indicated pollution of downstream dams. Levels of lead (0.13–0.28 ppm) and cadmium (0.02–0.06 ppm) in water from downstream dams exceeded WHO safe limits for drinking water. Cadmium levels in polluted dams also exceeded the safe limit for agricultural use. Sediments of effluent-polluted dams had metal contamination factors ranging from 8.8 to 31.2 relative to the control, and fish from the dams had higher metal content and were unfit for human consumption. Metal levels were also measured along an urban stream to establish the sources of metals. The city’s industrial zone had the highest levels of metals, suggesting that industrial effluents were major sources of contamination. The environmental consequences and human health risks of the pollution of peri-urban water bodies from urban effluents are discussed.     

浑河水系着生藻类的群落结构与生物完整性

以辽宁省浑河水系为研究范例,调查了全流域范围内62个样点的着生藻类群落和水环境理化特征,并应用着生藻类生物完整性评价指数(P-IBI),结合栖息地环境质量评价指数(QHEI),对浑河流域水生态系统进行健康评价.结果表明:浑河水系着生藻类群落结构具有明显的空间异质性,浑河水系的采样点可划分为4组(Group),不同组间的着生藻类群落结构、物种多度、密度和香农多样性指数均存在明显差异.典范对应分析(CCA)结果显示,驱动浑河着生藻类群落结构形成的水环境因子为铵氮( NH4+-N)和活性磷(PO43--P).P-IBI和QHEI在浑河水系某些河段上的评价结果有较大出入,但从全流域尺度上看,P-IBI和QHEI的评价结果基本一致,表现为浑河上游的苏子河健康状况较好,而上游的浑河以及中下游的浑河干流健康状况较差.     

Occurrence,distribution and possible sources of organochlorine pesticides in peri-urban vegetable soils of Changchun,Northeast China

The characterizations of residue levels and sources of organochlorine pesticides (OCPs) in soils are necessary to evaluate the potential pollution and risks of OCPs to the ecosystems and human health. A total of 51 surface soil samples were collected from peri-urban vegetable fields of Changchun and 13 OCPs were analyzed to learn the composition, spatial distribution and sources. The concentrations were in the ranges of 0.94–107.8 ng g^?1 for DDTs, 0.89–98.3 ng g^?1 for HCHs, 0.22–18.20 ng g^?1 for Chlordanes, nd–4.49 ng g^?1 for aldrin and nd–9.66 ng g^?1 for dieldrin, respectively. The total OCPs concentrations ranged from 2.44 to 177.1 ng g^?1 and the higher residues were mainly distributed in northeast and southwest sites, as well as sites along the Yitong River. According to the concentrations and detection frequencies, DDTs and HCHs were the most dominant compounds. Compositional analysis and principal component analysis suggested that DDT, HCH and chlordane in most soil samples derived from historical application except the slight fresh introduction at some locations. There exist a variety of OCPs residues in peri-urban vegetable soils of Changchun, but it is still safe and suitable for agricultural production for the most part, and some specific locations with high OCPs residues ought to be a cause for concern.     

Chemical analyses of water, sediment and biota in two small streams in southwest Germany

As a component of the VALIMAR project a comprehensive chemicalanalysis study was conducted in two small streams, the Körsch andthe Krähenbach, in southern Germany. The investigated pollutantswere heavy metals (HM), polycyclic aromatic hydrocarbons (PAHs),polychlorinated biphenyl's (PCBs) and a set of 33 pesticides.Samples from stream water, sewage treatment plant effluents,stream sediment and fish were analyzed. In the stream water, HMand PAHs showed slightly higher concentrations in the Körsch thanin the Krähenbach, whereas the pesticide concentrations (mainlyplant protective agents) were significantly higher in the Körschthan in the Krähenbach. Because of their similar occurrence andconcentrations in the Körsch water and in the sewage treatmentplant effluent, it appears that most of the pesticides wereintroduced into the river via the sewage treatment plant. Only inthe cases of terbuthylazine, triallate, chlorfenvinfos,metazachlor and mecoprop were the occurrence and concentrationsin the Körsch higher suggesting that run-off was the mostimportant route for these five compounds in this stream.The sediments of the two streams clearly differed in terms ofpollutant concentration. Polycyclic aromatic hydrocarbons, PCBsand HM were found in slightly higher concentrations in the Körschthan in the Krähenbach whereas pesticide concentrations weresignificantly higher in the Körsch. Results of each samplingdemonstrated extreme variations, due to frequent high-watersituations that led to high turnover and wash out of thesediment. In the sediment samples, most of the detected compoundswere more lipophilic than were those detected in water.Brown trout (Salmo trutta f. fario) and loach (Barbatulabarbatula) were sampled directly from the natural streams, from astream water fed bypass exposure system, and from a controlsystem in the laboratory. In the case of PAHs, PCBs andpesticides, concentrations were higher in fish exposed to theKörsch water than to the Krähenbach water. Heavy metals did notdifferentiate between the two streams. Polychlorinated biphenylsand pesticides showed higher concentrations in fish from thefield, which can be explained by longer exposure periods. Incontrast, PAHs showed the lowest concentrations under fieldconditions. Polycyclic aromatic hydrocarbons were possiblydisplaced by other compounds of high concentration. The pesticidepatterns in trout were quite similar in the different exposuretypes with primarily lindane, PCP and trifluraline contributingto these pattern changes. In loach, larger variations in allcontaminant concentrations were found but the same threecompounds also contributed most to the observed pattern changes.The analytical results were compared with various internationalobjective values for a good water quality as well as with valuesfrom other studies concerning the pollutant concentrations ofsediment and fish. All collected chemical data form a basis forthe biomarker investigations conducted by the other participantsof the VALIMAR project in order to find correlations betweenbiomarker responses and chemical pollution data of the twostreams.     

Metal concentrations in water,sediment and sharptooth catfish Clarias gariepinus from three peri-urban rivers in the upper Manyame catchment,Zimbabwe

Concentrations of zinc, cadmium, chromium, nickel, lead, copper and iron were measured in flowing water, riverbed sediments and tissues of sharptooth catfish Clarias gariepinus from three rivers in the upper Manyame catchment over seven months in 2008–2009. The Manyame and Mukuvisi rivers are severely polluted by industrial and domestic effluent, whilst the Gwebi River is not influenced by urban effluent. Key water quality parameters, including dissolved oxygen and conductivity, clearly showed a pollution gradient in the Mukuvisi and Manyame rivers, but water quality in the Gwebi River was good. Levels of zinc, iron, copper, nickel and lead in fish tissues from the three rivers sampled were unusually high, with zinc and iron concentrations being the highest in all the tissues. This was also positively correlated with the concentrations of these metals in water and sediments. Notable differences existed between the water (zinc and copper) and sediments (iron and zinc) of each river. The relatively high metal concentrations in the Gwebi River, as well as conductivity and dissolved ions, were explained by the geological influence of the Great Dyke in its subcatchment. Metals are bound in the sediment but these can be rapidly mobilised into water if environmental changes occur, therefore efforts to monitor and prevent further water quality deterioration are required. The results of this study may have significant negative implications for aquatic organisms and for human health through fish consumption and therefore risk assessment investigations are imperative.     

Distribution of Heavy Metals and Arsenic in Soils of Belgrade (Serbia and Montenegro) 1

Soils of the urban and suburban area of Belgrade have been hardly studied, especially concerning their concentrations of potentially toxic metals. The present paper is aimed at determining the possible pollution in soils. The total acid soluble concentrations of heavy metals and As in the samples were determined. It was found that they were arranged in the order Zn > Ni > Pb > Cr > Cu > As > Hg > Cd in samples collected in the examined area (the order of the elements is based on their arithmetic mean concentrations). In all the samples collected at 0–10 and 40–50 cm depths from 46 selected sites, the contents of Pb and Zn were lower at the depth 40-50 cm. Using target values given by the Dutch Ministry of Housing, Spatial Planning and Environment, it may be concluded that Belgrade soil can, for the most part, be regarded as unpolluted. Traffic seems to be one of the main sources of these metals, but the influence of other factors cannot be excluded.     

Heavy Metals (Cd,Cu, Ni,Pb, and Zn) Fractionation in River Sediments,Hamedan, Western Iran

Five heavy metals (Cd, Cu, Ni, Pb, and Zn) in river sediments from Abshineh River, Hamedan, western Iran, were fractionated by a sequential extraction procedure. Cu, Ni, Pb, and Zn existed in sediments mainly in residual fraction (mean 92%, 86%, 77%, and 65%, respectively), whereas Cd occurred mostly as organic matter (mean 41%) and exchangeable (mean 25%) fractions. The mean percent of mobile fraction of Cd, Cu, Ni, Pb, and Zn in contaminated sediments was 25, 13, 4, 24, and 10, respectively, which suggests that the mobility and bioavailability of the five metals in sediments probably decline in the following order: Cd = Pb > Cu > Zn > Ni. The metal levels were also evaluated according to the contamination factor, which revealed significant anthropogenic pollution of Cd and Pb.     

Heavy metals in Lake George, Uganda, with relation to metal concentrations in tissues of common fish species

The northern end of Lake George, Uganda, and its associated wetlands receive localized metal pollution from a former copper mine and tailings left after metal extraction. The aim of this study was to determine (i) whether the heavy metals are a threat to the biology of the major commercial fish species and (ii) whether consumption of the fish threatens human health. Concentrations of copper, zinc, cobalt and nickel in detrital sediments, plankton, and five fish species from sites in Lake George, the Kazinga Channel and Lake Edward (which are inter-connected) were determined using atomic absorption spectroscopy. The detrital sediments of Hamukungu Bay, Lake George, had average concentrations (g/g dry weight) of 96.3 zinc, 270.4 copper, 57.4 cobalt and 42.8 nickel. There were no significant differences between the Hamukungu Bay and the North Lake George site of Bushatu: both receive inflows from the mining activities. Concentrations of copper and zinc were significantly higher than background values from unpolluted freshwater ecosystems. Plankton samples showed a metal concentration gradient consistent with a gradient from the source of pollution in northern Lake George, along the Kazinga Channel to Lake Edward. The liver tissues of fish had markedly higher concentrations of copper and zinc than flesh. Concentrations of cobalt and nickel were relatively low. The highest mean concentrations of metals in liver tissue occurred in Oreochromis leucostictus (189.0 g/g Cu) and Bagrus docmac (187.5 g/g Zn) whilst the lowest occurred in Oreochromis niloticus (15.3 g/g and 78.2 g/g dry weight copper and zinc, respectively). However, O. niloticus contained the highest concentrations of cobalt (11.2 g/g) and nickel (3.8 g/g). Liver Somatic Indices (LSI) of the fish species from the different sites indicated a reduction of LSI in those fish from the most contaminated zones of northern Lake George compared with all other sites. This suggests there could be anatomical and physiological abnormalities linked to the heavy metal pollution. The flesh had only low concentrations of metals; well within international guidelines for consumption. A person would have to consume 9 kg of fresh flesh of Clarias sp. and 65 kg of O. leucostictus daily to exceed the WHO recommended intake for copper, and even more for other metals. This implies that currently metal pollution in Lake George presents an ecological rather than a human health concern.     

Assessment of Heavy Metal Contamination in the Sediments of the Shuangtaizi Estuary Using Multivariate Statistical Techniques

In order to assess heavy metal pollution of sediment samples collected from Shuangtaizi estuary, contamination factor (CF) and multivariate statistical analyses, including principal component analysis (PCA), cluster analysis (CA) and correlation analysis, are carried out in this paper. CF confirms that Pb, Cu and Hg concentrations are very low and all fall within the range of background, while Zn and Cd demonstrate moderate contamination (in A10, A13, A15, A16 and A17 sites) and very high contamination (in A10, A13, A15 and A17 sites), respectively. The PCA indicates that four significant principal components (PCs) are extracted, explaining 88.959% of total variance, which suggests that Pb, Cu and Zn are mainly associated with organic carbon (OC). The result from CA is consistent with that obtained from PCA, classifying that the heavy metals in two clusters derive from different sources. Correlation analysis supports the conclusions from PCA and CA, elucidating the relationships between heavy metals and particle sizes of the sediments.     

Oligochaeta of the middle Po River (Italy): principal component analysis of the benthic data

The application of principal component analysis to two types of habitat (the benthos of macrophytes and of central river bed) enabled us to single out some of the factors that affect the dynamics and the structure of the oligochaete population and its various reactions to environmental conditions. As regards macrophytes, the distribution of the variables on the basis of the first component is correlated, to a certain extent, with a seasonal factor without any significant differences among sites. The largest population is most closely correlated with the summer months. In fact, we found that the Naididae and Tubificidae species generally develop in larger numbers at higher temperatures. For the Tubificidae, we could detect a precise seasonal cycle. In the central river bed habitat, the first component was correlated with the river discharge, which determines the granulometric characteristics of the sediment; we noticed a correlation among the sites that have the same characteristics, regardless of sampling site or date. The species which correlate most closely among themselves are the Tubificidae Limnodrilus hoffmeisteri, Tubifex tubifex, L. udekemianus and L. profundicola, which are very characteristic of environments that contain abundant organic matter. The second component is correlated with temperature, and hence with the availability of oxygen, which determines the presence and the abundance of more sensitive species.     

Response to nutrient additions by the plant growth forms of sand-plain lowland fynbos,South Africa

The growth response (foliage projective cover: FPC) of the plant growth forms of lowland fynbos, South Africa to a complete factorial fertilizer addition of nitrogen (N), phosphorus (P) and a mixture of all essential nutrients excluding N and P (M) was monitored for two years. Ordination by correspondence analysis revealed a successional trend as the vegetation aged, with increases in proteoid, and to a lesser extent restioid, and decreases in reseeding ericoid, graminoid, geophyte and annual plant FPC but no discernible effects due to fertilizer application. Analysis of covariance revealed significant increases in restioid, graminoid and annual plant FPC with N-addition, 1 and 2 yr after fertilizer addition and of total FPC with N-addition for only one year. Of the other nutrient treatments, only an increase in annuals with P-addition and a reduction in the rate of decline of reseeding ericoid with M-addition were found, both after two years. Thus nitrogen may often limit vegetative growth of at least the herbaceous species. The herbaceous growth forms are more plastic in their morphological growth responses to nutrient additions than the slow-growing, stress tolerant, evergreen shrub species. The vegetation appears to be resilient, at least in the short-term, to a disturbance of this magnitude. However, chronic nutrient applications and those of larger magnitude will probably result in long-term changes in species composition, with an increase in ephemeral, nutrient demanding species.Abbreviations FPC = Foliage Projective Cover     

Changes in the algal composition and water quality of the Sundays River,Karoo, South Africa,from source to estuary

A 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 downstream with peaks in algal abundance being ascribed to peaks in nutrient concentrations. Cyanobacteria and euglenoids were present in the upper and middle reaches of the river, but were absent downstream. Dinoflagellates became more important downstream, especially in the estuary. Dominant species, reaching high concentrations along the river, included Nitzschia frustulum, Nitzschia capitellata, Carteria klebsii, Chlorella vulgaris and Anabaena species. The presence of the diatom Eolimna comperei is a first record of its occurrence in South Africa. The Sundays River can be described as a brackish, hard water system with high nutrient concentrations in certain sections. The most important contributors to high nutrient concentrations were point sources in the vicinity of towns along the river banks, as well as diffuse sources contributing to high nitrogen concentrations in the fertile Sundays River valley. Increasing salinities were due to pollution, evaporation and agricultural activities in the valley.     

Diatoms as water quality indicators in the upper reaches of the Great Fish River,Eastern Cape,South Africa

This study focused on the spring-fed upper reaches of the economically important Great Fish River with the aim of determining if diatoms could be used for biomonitoring in semi-arid conditions in southern Africa. Five sites were monitored monthly from 2010 to 2012. Of the 269 diatom taxa belonging to 51 genera identified, the dominant taxa were mostly those considered to be pollution-tolerant: Amphora pediculus, Craticula buderi, Fragilaria biceps, Nitzschia frustulum, Nitzschia paleacea, Planothidium lanceolatum and Rhopalodia gibba. A number of diatom-based numerical indices were used to infer water quality, including the generic diatom index, the specific pollution sensitivity index, the biological diatom index, and percentage pollution-tolerant valves, which forms part of the UK trophic diatom index. All index scores showed the Great Fish River to be impacted, and showed significant correlations of diatom species abundance with pH, NO₃-N, electrical conductivity, NH4-N and CaCO_3. Analysis revealed EC and NO3-N as the main environmental drivers affecting diatom community composition, followed by pH and PO4-P. The percentage of diatom deformities at all sites was high, at 3.5%. Diatom indices showed the river to be impacted by decades of agricultural activity, which was confirmed by chemical water analysis. Thus diatom indices can be used for biomonitoring in semi-arid areas.