published_or_final_version / Geography and Geology / Master / Master of Philosophy

by Lau Wai Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1981. / Bibliography: leaves 189-205.

University of Macau / Institute of Chinese Medical Sciences

Metal-contamination of lakes simplifies food webs and reduces the efficiency of energy transfer to top trophic organisms, such as yellow perch (Perca flavescens). Benthic invertebrate community composition and yellow perch diet, growth and activity levels from lakes along a metal-contamination gradient were used to assess the importance of a naturally diverse prey base for maintaining energy transfer to growing fish, and how this is disrupted by metal-contamination. As perch grow larger, they shift their diet to larger prey; otherwise, the activity costs of foraging for many, small prey, instead of a few large prey, become too high and the fish stop growing. Metal contaminated lakes have less diverse zoobenthic communities, particularly the lack of large bodied invertebrate taxa, forcing perch to rely on smaller benthic prey. Perch from metal-contaminated lakes display slow growth and poor condition during benthivory. Estimates of fish activity, using the activity of the glycolytic enzyme Lactate dehydrogenase in perch white muscle tissue as a proxy, suggest that diet shifts to larger prey lower activity costs and may explain how diet shifts maintain growth efficiency as perch grow larger. Perch from metal-contaminated lakes cannot benefit from the energetic advantages of switching to larger prey and thus exhibit poor growth.

D.Phil. / The entire Olifants . River Catchment is subjected to increasing afforestation, agricultural, domestic, mining, industrial, irrigation and urbanisation activities. These activities have a profound effect on the water quality of the river and its tributaries. This is cause for concern for the water users in the upper catchment, and because the Kruger National Park, one of its downstream water users, is extremely dependent on water of a satisfactory quality to sustain its various ecosystems. It is therefore vitally important to determine to what extent activities in the Upper Catchment of the Olifants River (Mpumalanga), especially in the Witbank and Middelburg areas, influence the water quality of the river. Point sources of pollution in the upper reaches include mining and industrial activities as well as water care works located at various points along the river. These were addressed in a Water Research Commission Project (No. 608/1/97) titled "Lethal and sublethal effects of metals on the physiology of fish: An experimental approach with monitoring support". Although sixteen localities were chosen for the initial project, this study only focussed around the metal ecotoxicology at two localities (Steenkool Spruit and Witbank Dam) in the upper catchment and the effect of metals (copper and zinc) on fish blood physiology. In aquatic ecosystems water quality is an important variable and full assessment of water quality, of Steenkool Spruit (locality 3) and Witbank Dam (locality 7), included evaluation of the chemical, physical and biological characteristics at each of the localities. Water and sediment samples were collected seasonally during the study period, February 1994 to May 1995, and the chemical and physical water quality variables were measured. During the study period three metal bioaccumulation indicator species, Labeo umbratus, Clarias gariepinus and Labeo capensis, were captured from which tissue (gills, liver, muscle and skin) samples were collected. These samples as well as water and sediment samples, were analysed for aluminium, chromium, copper, iron, manganese, nickel, lead and zinc concentrations, using atomic absorption spectrophotometry. In the past routine monitoring of chemical and physical water quality characteristics left scientists and managers with a sizeable pool of data which is often difficult but not impossible to interpret. To standardise and summarise this collection of data an aquatic toxicity index (ATI), WATER2 was developed by Wepener et at (1992). The present study attempted to expand and refine WATER2, which has resulted in the establishment of a new ATI, RAUWater.

M.Sc. / The catchment area of the Olifants River has, over a number of years, been exposed to extensive mining, agriculture and urbanisation activities in the Witbank-Middelburg and Phalaborwa regions which has largely contributed to the deterioration of water quality. Of major concern is the influence anthropogenic activities have on the aquatic ecosystem of the Olifants River within the Kruger National Park and how me health of fish residing In these waters is affected. To determine fish health, a biological monitoring method, the Health Assessment Index (H41), was tested for the first time In South Africa. Four surveys were conducted at Mamba and Balule In the Olifants River, Kruger National Park during 1994 (February, May, July and November). An additional survey was conducted in February 1995 at Loskop Dam. Samples of water and sediment were taken for analysis of metals and physical and chemical water parameters. A maximum of 20 Clarias gariepinus fish were sampled at each location. Evaluation of the fish was done according to guidelines set in the HAI and parasite population composition (prevalence, abundance, mean intensity) was determined. Organ and tissue samples including gills, liver, muscle and skin were analysed for the bioaccumulation of chromium, copper, Iron, manganese, nickel, lead, strontium and zinc, using atomic absorption spectrophotomeby. Metal concentrations in the water at Mamba and Balule were within guideline limits, whereas concentrations at Loskop Dam were above guidelines. As reflected by the application of the Aquatic toxicity Index, Loskop Dam presented with the poorest water quality followed by Mamba then Balule. It was found that certain physical and chemical variables namely fluoride, potassium, sulphate and total dissolved solids concentrations at Mamba and Balule were relatively high, particularly during drier months. Metals accumulated in organs and tissues, with the highest concentrations In the gills followed by the liver, skin and muscle. The discriminant analysis, utilising metal bloaccumulation, discriminates between water quality at Mamba and Balule, revealing a 100 % classification probability for each survey. Values obtained In the application of the HAI indicated that variables with good predictor accuracy were plasma protein, all parasites, endoparasites, liver, white blood cell counts, ectoparasites, skin, fins and gills. The discriminant function for the HAI generally Indicated variables similar to those exhibiting high predictor accuracy. The discriminant function showed relatively low classification probability for each survey. In case 1, where separate endo- and ectoparasite variables were Included in the determination of me discriminant function, probability for me entire study ranged between 47.5 % and 84.2 %. In case 2, where endo- and ectoparasite variables were given a refined score rating system, probability ranged between 62.5 % and 100 %. The low classification probability Indicates either the Importance of repetitive testing for this technique or a total departure from it. Results showed that fish populations with higher HAI values are found in water of poorer quality (Mamba), while healthier fish populations i.e. with lower RAI values are found In water of better quality (Balule). Parasite data shows a similar tendency by indicating that ectoparasites are abundant in water of higher quality, while endoparasftes increase in water of poorer quality. The HAI reflects the condition of fish populations in relation to their aquatic environment, therefore, the HA/ gives an indication of water quality and should be used as a first level screening tool. If complemented by a parasite survey, distinguishing between endoand ectoparasites, the results from the HAI will be enhanced.

No description available.

Thesis (PhD) -- Stellenbosch University, 2004. / ENGLISH ABSTRACT:Heavy metals are persistent environmental contaminants whose sources of inputs into the environment are both natural and anthropogenic. The levels of heavy metals (cadmium, copper, nickel, lead and zinc) in the False Bay intertidal zone were measured in the water, sediments and invertebrate species between August 2000 and August 2001. The results of the water and sediment analyses revealed that most pollution was associated with the northern shore of the bay between Strand and Muizenberg, where the most populated and industrial catchments occur. Significant spatial variations occurred, indicating the presence of localised contamination, while seasonal variations may be related to changes in precipitation and runoff at different times of the year. The concentrations of cadmium, nickel and lead were occasionally higher than the levels recommended by the South African Water Quality Standards. The possible sources of pollution at the different sites are also discussed. The concentrations of the five metals in the different invertebrate species (Oxystele tigrina, 0. sinensis, Choromytilus meridionalis, Patella oculus, Patiriella exigua and Tetraclita serrata) also revealed significant seasonal and spatial variations, with both the soft tissues and shells accumulating heavy metals. The barnacle T serrata from Rooiels had the highest cadmium concentration (70.67 J.lg/g dry weight), which may be related to historic pollution inputs from the military activities which took place at a weapons testing site at this site between 1987 and 1994, although no evidence was found to confirm this. The periwinkle 0. tigrina from Strand had the highest copper concentration (70.25 J.lg/g) while the limpet P. oculus from the same site had the highest nickel concentration (35.75 J.lg/g). The shells of the mussel C. meridionalis from Muizenberg had the highest concentration of lead (25.75 J.lg/g). Since cadmium occurs as a constituent of phosphate fertilisers used widely in the False Bay catchments, the effects of cadmium exposure on the different species were investigated during 14-day laboratory exposures to 200 and 400 J.lg/LCdCh. The results revealed a general pattern of tissue metal increase in the exposed organisms, followed by slight reductions after decontamination in clean seawater. The viscera and kidneys of C. meridionalis accumulated most of the dissolved cadmium. The shells of the mussels also accumulated cadmium, indicating the possible use of shells as a detoxification matrix. / AFRIKAANSE OPSOMMING:Swaarmetale is persisterende omgewingskontaminante waarvan die insetbronne beide natuurlik of van menslike oorsprong kan wees. Die kontaminasievlakke van swaarmetale (kadmium, koper, nikkel, lood en sink) in die Valsbaai tussengetysone is in die water, sedimente en invertebraatspesies bepaal vanaf Augustus 2000 tot Augustus 2001. Voorlopige resultate van die water- en sedimentontledings het getoon dat die meeste besoedeling by die noordelikke oewer van die baai voorgekom het tussen Strand and Muizenberg, waar die mees digbewoonde en ge-industrialiseerde opvangsgebiede is. Betekenisvolle ruimtelike en seisoenale variasie het in die konsentrasies van swaarmetale voorgekom, met die ruimtelike variasie wat moontlik gelokaliseerde kontaminasie aandui terwyl die seisoenale variasies weer verband mag hou met veranderings in die neerslag en afloop gedurende verskillende tye van die jaar. Die konsentrasie van kadmium, nikkel en lood was somtyds hoer as die vlakke wat deur die Suid-Afrikaanse Waterkwaliteitsstandaarde voorgestel word. Die moontlike bronne van besoedeling in die verskillende areas is ook in bespreking genoem. Die konsentrasies van die vyf swaametale in die verskillende invertebraatspesies (Oxystele tigrina, 0. sinensis, Choromytilus meridionalis, Patella oculus, Patiriella exigua and Tetraclita serrata) het ook seisoenale en ruimtelike variasies vertoon, die swaarmetale het in die sagte weefsel en skulpe van die invertebrate geakkumuleer. Die hoogste gemiddelde konsentrasie van kadmium (70.67 ).lg/g droe massa) is in die heel-liggaam monsters van die eendemossel T serrata gemeet wat by Rooiels versamel is. Die vlakke mag verband hou met die oprigting en aktiwiteite van die wapentoetsingsaanleg in die opvanggebied van die Rooiels lokaliteit tussen 1987 en 1994, maar geen bewyse daarvan is gevind nie. Die tolletjie, 0. tigrina wat in die 10kaliteit by Strand versamel is het die hoogste gemiddelde konsentrasie koper gehad 70.25 pig droe massa), terwyl die klipmossel P. oculus by dieselfde versamelpunt die hoogste konsentrasie nikkel (35.75 ).lg/gdroe massa) gehad het. Eksperimentele studies is ook uitgevoer op vier invertebraat spesies wat vir 14 dae in akwaria blootgestel is aan see-water met 200 en 400 p,g/L CdCh, en daama gedekontamineer is in skoon seewater. / The NRF and the University of Stellenbosch, for funding this study.

Szeto Tsz Kwan Leo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 112-120). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.v / Table of Contents --- p.vi / List of Tables --- p.ix / List of Figures --- p.x / Abbreviations --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Heavy metals contaminations in Shing Mun River --- p.1 / Chapter 1.1 --- Importance of copper regulation and role of liverin copper metabolism --- p.6 / Chapter 1.1.1 --- Role of copper --- p.6 / Chapter 1.1.2 --- Toxicity due to unbalanced copper regulation --- p.7 / Chapter 1.1.3 --- Function of liver in copper detoxification --- p.9 / Chapter 1.2 --- Aims and rationale of this research --- p.11 / Chapter Chapter 2 --- Heavy metal concentrations of tilapia samples collected from Shing Mun River --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.1.1 --- Sampling sites - Fo Tan and Siu Lek Yuen Nullah --- p.12 / Chapter 2.1.2 --- Tilapia samples collected from the sites --- p.16 / Chapter 2.1.3 --- Tilapia as a study model --- p.18 / Chapter 2.1.4 --- Bioavailability of heavy metals in water --- p.19 / Chapter 2.1.5 --- Metal content in liver --- p.20 / Chapter 2.1.6 --- Aim of this chapter --- p.20 / Chapter 2.2 --- Materials and Methods --- p.22 / Chapter 2.2.1 --- Collection of control and field samples --- p.22 / Chapter 2.2.2 --- Heavy metal concentrations determination --- p.23 / Chapter 2.2.3 --- Homogenization of liver cells --- p.24 / Chapter 2.2.4 --- Subcellular fractionation --- p.24 / Chapter 2.2.5 --- Determination of copper and zinc content in each subcellular fraction --- p.253 / Chapter 2.3 --- Results --- p.27 / Chapter 2.3.1 --- Physical data --- p.27 / Chapter 2.3.2 --- Metal concentrations in liver and muscle --- p.27 / Chapter 2.3.3 --- Copper and zinc subcellular distribution in liver cell --- p.33 / Chapter 2.4 --- Discussion --- p.36 / Chapter 2.4.1 --- Difference in metal concentration between sites --- p.36 / Chapter 2.4.2 --- Copper contamination in water and fish organ (muscle and liver) from the Shing Mun River --- p.36 / Chapter 2.4.3 --- Comparison of metal content in muscle and liver at Fo Tan site with previous studies --- p.39 / Chapter 2.4.4 --- Copper and zinc concentrations in the liver of tilapia --- p.42 / Chapter 2.4.5 --- Copper and zinc sebcellular distribution in the liver of tilapia --- p.43 / Chapter Chapter 3 --- Column chromatography of hepatic proteins from tilapias --- p.44 / Chapter 3.1 --- Transport of metals from circulatory system to liver --- p.44 / Chapter 3.1.1 --- Copper transporting plasma proteins in vertebrates --- p.44 / Chapter 3.1.2 --- Copper uptake into hepatocytes --- p.45 / Chapter 3.1.3 --- Intracellular metabolism of copper --- p.48 / Chapter 3.1.4 --- Mechanism of copper toxicity following excess accumulation --- p.49 / Chapter 3.1.5 --- Aim of this chapter --- p.50 / Chapter 3.2 --- Materials and Methods --- p.51 / Chapter 3.2.1 --- Purification of liver cytosolic proteins by gel-filtration column chromatography --- p.51 / Chapter 3.2.2 --- Copper content detection in elution --- p.52 / Chapter 3.2.3 --- Analysis of peaks from elution profile using tricine gel SDS PAGE --- p.53 / Chapter 3.3 --- Results --- p.55 / Chapter 3.3.1 --- Gel-filtration liquid chromatography elution profiles --- p.55 / Chapter 3.3.2 --- SDS PAGE analysis of peaks in elution profiles --- p.51 / Chapter 3.4 --- Discussion --- p.54 / Chapter 3.4.1 --- Comparison of gel filtration profiles of sample liver cytosol between sites and sexes --- p.64 / Chapter 3.4.2 --- Possible proteins in peaks found in the gel filtration profiles --- p.64 / Chapter 3.4.3 --- Common copper-indeced proteins --- p.67 / Chapter 3.5 --- Conclusion --- p.70 / Chapter Chapter 4 --- Two-dimensional electrophoresis of hepatic cutosol of tilapias caught from Shing Mun River and copper-treated HEPA T1 cell --- p.72 / Chapter 4.1 --- Introduction --- p.72 / Chapter 4.1.1 --- The need of ´بin vitro' experiment --- p.72 / Chapter 4.1.2 --- Choice of cell line --- p.73 / Chapter 4.1.3 --- Aim of this chapter --- p.74 / Chapter 4.2 --- Materials and Methods --- p.76 / Chapter 4.2.1 --- HEPA T1 cell cultivation --- p.76 / Chapter 4.2.2 --- Copper exposure of HEPA T1 cell --- p.77 / Chapter 4.2.3 --- Subcellular protein extraction of the copper-treated HEPA T1 cells --- p.77 / Chapter 4.2.4 --- Bicinchoninic Acidic (BCA) Protein Assay --- p.79 / Chapter 4.2.5 --- Two-dimensional gel electrophoresis --- p.79 / Chapter 4.3 --- Results --- p.83 / Chapter 4.3.1 --- Graphical presentation of spots observed on 2-dimensional gel of field samples and copper-injected samples --- p.33 / Chapter 4.3.2 --- Graphical presentation of spots detected on 2-dimensional gel of HEPAT1 cells --- p.84 / Chapter 4.3.3 --- Comparison of matched spots on 2-dimensional gels among control and copper-treated HEPAT1 cells --- p.97 / Chapter 4.4 --- Discussion --- p.105 / Chapter 4.4.1 --- Comparison of the spot patterns between field sample and copperOtreated HEPA T1 cells --- p.105 / Chapter 4.5 --- Conclusion --- p.107 / Chapter Chapter 5 --- General Discussions --- p.108 / Chapter 5.2 --- Research Overview --- p.108 / Chapter 5.2 --- Characterization of metal binding proteins from the cytosol of liver of tilapia --- p.109 / REFERENCES --- p.112

published_or_final_version / abstract / toc / Ecology and Biodiversity / Master / Master of Philosophy