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The Landdroskop area in the Hottentots Holland Mountains as a refugium for melanistic lizard species : an analysis for conservationCostandius, Eloise 03 1900 (has links)
Thesis (MSc (Botany and Zoology))--University of Stellenbosch, 2005. / The Dwarf Crag Lizard, Pseudocordylus nebulosus, is one of several relict ectotherm species associated with the mistbelt of the Cape folded mountain belt. Prior to this study, it was only known from a single locality in the Hottentots Holland Mountains. In this study, the distribution range and microhabitat preferences of P. nebulosus were determined and resource partitioning among the three melanistic cordylids (C. oelofseni, P. capensis and P. nebulosus), co-occurring in this area, investigated. Using the locality where P. nebulosus was first discovered as centerpoint, surveys were conducted in all directions and the occurrence of all three melanistic species recorded. The previous known range of P. nebulosus, of only 0.04 km2, was extended to 11 km2. Of the three melanistic cordylids, P. nebulosus has by far the smallest range, completely overlapping with the ranges of both the other two melanistic cordylids. Pseudocordylus nebulosus was found to show a distinct affinity for water bodies such as mountain streams and seepage areas. Distinct differences in resource partitioning were found among the three species regarding crevice selection, which will prevent any significant competition during periods of environmental stress. Cordylus oelofseni preferred small crevices at ground level, P. capensis preferred large rock structures high above ground level and P. nebulosus utilized intermediate sized rock structures. Because of its relatively small range and melanistic colour, P. nebulosus could be a key indicator species of environmental change. Although the lack of objective fire management and global warming may be immediate threats to the survival of this species, possible illegal collection due to the easy access via the popular hiking trail in the area, is probably less significant a threat than was previously thought. Although its known range has been extended considerably, it is recommended that the Vulnerable status of P. nebulosus be maintained. This study provides baseline data that could be useful in future monitoring programmes to predict declines and fluctuations.
In the second part of this study, the aim is to provide information about sexual dimorphism in P. nebulosus and to discuss the observed variation in sexual size dimorphism among montane cordylids. Data were recorded for all P. nebulosus individuals encountered in the Landdroskop area (Hottentots Holland Mountains), irrespective of size and sex. The total sample of 87 lizards recorded, consisted of 26 adult males, 49 adult females and 12 indeterminates. Size at sexual maturity was determined at 60 mm snout-vent length (SVL) for both sexes. The highly female-biased adult sex ratio recorded for P. nebulosus, is considered to be due to sampling error, gravid females probably basking more than males, making them easier to locate during searches. Generation glands were found to be present in males only and the number present was significantly correlated to body size. Both adult males and adult females possessed active femoral glands, but males had significantly more than females. Females were found to reach larger body sizes than males, but adult males had relatively larger heads than females. No significant difference in scar frequency was found between the male and female samples. Variation in sexual size dimorphism among montane cordylids is discussed and the need for more comprehensive data pointed out. The female-biased sexual size dimorphism in P. nebulosus and its sister species, P. capensis, is tentatively ascribed to fecundity selection for offspring to be large at birth in order to survive in a predictable unfavourable environment at high altitudes. Sexual dimorphism in head size is ascribed to sexual selection, males probably being territorial as in many other cordylids.
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Evaluating success of an integrated control programme of Hakea sericea Schrader (Proteaceae) in the Western and Eastern Cape Provinces, South Africa through cartographic analysisTe Roller, Kerry Sharon 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: One of the most threatening factors to the biodiversity of the Cape Floristic Region is that of invasive alien
organisms. A contestant for the most noxious of these fynbos threatening organisms is
Hakea sericea. When left to grow uncontrolled, this small Australian tree forms impenetrable stands that out
compete the natural vegetation. Due to the threat this plant poses, an extensive and integrated control
programme was initiated to reduce its numbers to a level where it can no longer compete successfully with the
indigenous flora. This control programme consists of a carefully devised slash and burn method, chemical
herbicides and four biological control agents. Little literature surrounding the success of this control programme
is available. Two data sets, Fugler (1979) and Protea Atlas Project 2001, recording the distribution and density
of the plant at the height of its invasion and twenty two years later are compared to one another using
Geographical Information System techniques. Success of control measures is reflected by: (1) a reduction of
340 135 ha in total invaded by H sericea, (2) a reduction in density and (3) shifts in patterns of average rainfall,
altitude, slope and aspect of the areas associated with different density categories of this species. These data
provide reward for all those involved in the control programme by justifying efforts associated with the control
of the invader. Furthermore, the findings of this project also highlight the value of the control programme as
well as indicate how future research should be concentrated in order to perfect the programme. / AFRIKAANSE OPSOMMING: Uitheemse indringerplante is een van die enkele belangrikste faktore wat die Kaapse Fynbos biodiversiteit
bedreig. In hierdie geval is Hakea sericea een van die mees kompeterende spesies. Hierdie klein Australie
boompie ontwikkel, indien ongekontroleerd gelaat, tot 'n ondeurdringbare digte woud wat natuurlikke
plantegroei verdring. Dit is weens hierdie faktor dat ekstensiewe en geintegreerde kontroleringsprogramme
ontwikkel is om die getalle van bome na die vlakke te verlaag waar dit geen bedreiging vir inheemse flora sal
inhou nie. Die kontroleringsprogramme maak onder andere van chemiese onkruiddoders, vier biologiese
beheermiddels, ontbossing en beheerde brande gebruik. Min literatuur is beskikbaar oor die sukses wat verkry
word met die programme. Twee datastelle elk van Fugler (1979), bevattende data oor digtheid en verspreiding
van die plante 22 jaar tevore en die Protea Atlas Projek (2001) word vergelyk met behulp van Geografiese
Inligtingstelsel (GIS) tegnieke. Die sukses van die beheer maatreels word weerspieel in: (1) die totale afname
van 531 229 ha to 340 135 ha ingedring deur H. sericea, (2) afname in die digtheid en (3) verskuiwing in die
algemene reenval-, hoogte-, helling- en liggingspatrone wat geassosieer word met die verskillende
digtheidskatogoriee van die spesie. Die resultate bied regverdiging vir die kontroleringsprogramme van
indringerplante. Ook beklemtoon die projek die waarde van kontroleringsprogramme en dui aan waarop
toekomstige navorsing moet konsentreer om die programme te vervolmaak.
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Invasive perennial species in an agricultural area of the Western Cape Province : distribution and relationship with various land-use typesMidgley, John Claude 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: This project consists of two botanical investigations in an agricultural area of the Western Cape
Province. A farm known as De Rust, in the Elgin Valley, was used to sample the geographic location,
density, height and life stage of six prominent invasive plant species in various land-use categories.
In the first investigation, the density, height and age structures of the six invasive species populations
were analyzed. The density distribution of the six species was also displayed cartographically. Species
were then ranked according to the potential threat that they pose to the conservation of the remaining
natural areas on the farm. Results indicated that Acacia mearnsii and Acacia saligna are the major
invaders at De Rust and that Hakea sericea can be considered as an emerging invader.
The second investigation explores the statistical relationship between the various land-use categories
and density, height and age of the six prominent invaders identified in the first investigation. The loglikelihood
ratio analysis of observed frequencies resulted in statistically significant (P<0.01; P-values
range between 1.35 x 10-3 and 2.7 x 10-224) relationships between certain land-use types and certain
invasive species. A conclusion was reached that it could be useful to include land-use categories in
simulation models of invasive plant species distribution and spread. / AFRIKAANSE OPSOMMING: Hierdie projek behels twee botaniese ondersoeke in ‘n landbou gebied van die Weskaap. Die plaas
bekend as De Rust, in die Elgin Vallei, was gebruik vir die versameling van data te doen met die
geografiese ligging, plant digtheid, lengte en lewens stadium van ses prominente indringer plant
spesies in verskeie landgebruik kategorieë.
Die digtheid, lengte en ouderdomstruktuur van ses indringerspesies was in die eerste ondersoek
geanaliseer. Die verspreiding van digtheid was ook in kaarte uitgelê. Spesies was daarna volgens hulle
potentiële dreiging teen die bewaring van oorblywende natuurlike dele van die plaas in ‘n rangorde
geplaas. Resiltate dui aan dat Acacia mearnsii en Acacia saligna die belangrikste indringer plante op
De Rust is en dat Hakea sericea as ‘n opkomende indringer beskou kan word.
Die tweede ondersoek kyk na die verhouding tussen verskeie grondgebruik kategorië en die digtheid,
lengte en ouderdom van die ses prominente indringer spesies wat in die eerste ondersoek identifiseër
is. ‘n Log tipe ratios ontleding van bewaarde frekwensies het ‘n statisties belangrike uitkoms gehad
(P<0.01; P-waardes tussen 1.35 x 10-3 en 2.7 x 10-224) vir die verhoudings tussen sekere grondgebruik
tipes en sekere indringer spesies. Die gevolgtrekking was dat dit handig mag wees om grondgebruik
kategorieë in simulasies van indringer plant verspreiding te gebruik.
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The interaction between vegetation and near-surface water in a wetland system, Stellenbosch, South AfricaKareko, John K.(John Kariuki) 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Understanding the responses of individual plant communities to variations in
near-surface water levels and to water quality is a step towards determining the critical or
important factors applicable to a Rapid Wetland Assessment System.
This thesis describes and discusses factors associated with wetland plant
communities, with an attempt to predict changes in a wetland system. This study was
initiated with a primary aim of establishing the relationship between plant communities
and the variation in near-surface water levels in areas occupied by various plant
communities in the Middelvlei wetland system at Stellenbosch. A second aim was to
assess whether water quality had an influence on the plant communities.
Seven plant communities are identified and described from this particular wetland
system using standard Braun-Blanquet techniques (Typha capensis Reedswamp; Cyperus
textilis Sedgeland; Pennisetum macrourum Grassland; Juncus effusus Sedgeland;
Cyperus longus Sedgeland; Cliffortia strobilifera Shrubland and Populus canescens
Forest). The Typha capensis Reedswamp community is found in the wettest parts of the
wetlands, with a fluctuation in water table from 0.10 m above surface during the wet
season to 0.43 m below surface during the dry season. The Populus canescens Forest is
actively invading the wetland replacing the wetland species by modifying the wetland
hydrological condition. Water samples from 35 wells, collected on a monthly basis over
11 months, are used to assess sodium, magnesium, potassium, calcium, nitrate and
phosphate, pH, redoxs potencial and dissolved oxygen levels in each community, over
four seasons.
Both multivariate analysis (ANOVA) and regression tree analysis (CART) are
applied to evaluate differences between communities or groups of plant communities on a
seasonal basis. Direct gradient analysis (CCA) is used to determine the relationship
between plant communities and environmental variable gradients.
A wide variation in water quality condition between plant communities is present.
The Typha capensis Reedswamp community is associated with low nutrient levels
(phosphates and nitrates) in all seasons. The Cyperus textilis Sedgeland is associated with low levels of nitrates and high phosphate levels. The Juncus effusus Sedgeland displays
the highest phosphate concentration, occurring in summer, while low nitrate levels occur
in this community during all the seasons.
Dissolved oxygen in the near-surface water in this wetland is at very low
concentrations, and has no significant difference between communities. It plays no major
role in determining the occurrence and distribution of the plant communities.
Most of the water chemical constituents measured in this study are the result of
multiple complex relationships, with constituent variations occurring differently between
communities. A remarkable seasonal distinction in the chemical constituents in different
communities is present.
Despite the complex nature of the relationships between plant communities and
environmental factors, the low species diversity levels through the tendency for single
species dominance and the strong association of these communities with particular
environmental variables, the combination of these factors all add value to the use of
wetland vegetation as a good tool to indicate wetland condition. An effort to understand
wetland plant communities in relation to determining environmental factors would
promote the use of plant communities as user-friendly tools for wetland monitoring and
assessment. / AFRIKAANSE OPSOMMING: Om die reaksies van plantgemeenskappe teenoor variasies in naby-oppervlakte
watervlakke te verstaan, is die eerste krities-belangrike faktor die ontwikkeling van ‘n
sisteem om vleilande vinnig te assesseer. Hierdie studie se basiese mikpunt is om
verwantskappe te soek tussen plantgemeenskappe in die Middelvlei Vleilandsisteem en
wisseling in naby-oppervlak watervlakke. ‘n Sekondêre doel is om te bepaal of daar
enige korrelasie is tussen waterkwaliteit en die plantgemeenskappe teenwoordig in die
vleiland.
Sewe plantgemeenskappe is in hierdie vleilandsisteem geïdentifiseer en beskryf
deur gebruik te maak van standaard Braun-Blanquet tegnieke, naamlik die Typha
capensis Rietmoeras; Cyperus textilis Biesieveld; Pennisetum macrourum Grasveld;
Juncus effusus Biesieveld; Cyperus longus Biesieveld; Cliffortia strobilifera Struikveld
en ‘n Populus canescens Woud. Die Typha capensis Rietmoeras kom in die natste dele
van die vleilande voor, met vrywater wisselling vanaf 0.10 m bo grondoppervlakte,
tydens die nat-seisoen, tot 0.43 m onder grondoppervlakte tydens die droë seisoen. Die
Populus canescens Woud het die grootste wisseling in watervlak vanaf die
grondoppervlakte tot ten minste ‘n diepte van 1.0 m gehad. Dit blyk dat die Populus
canescens Woud besig is om die vleigemeenskappe aktief binne te dring deur die vleiland
uit te droog.
Water is maandeliks, oor 11 maande, uit 35 geperforeerde plastiek pype,
sogenaamde ‘putte’ onttrek, om natrium, magnesium, kalium, kalsium, nitrate en fosfate,
pH, redokspotensiaal en opgeloste suurstof vlakke se seisoenale wisseling te bepaal.
Beide veelvuldige analise (ANOVA) en regressie-analises (CART) is bereken om enige
betekenisvolle verskille tussen plantgemeenskappe te bepaal. Direkte Gradiëntanalise
(CCA) is gebruik om die verwantskap tussen plantgemeenskappe en gradiënte van
omgewingsveranderlikes te bepaal.
Groot variasies in waterkwaliteit tussen plantgemeenskappe is waargeneem. Die
Typha capensis Rietmoeras-gemeenskap is geassosieer met lae voedingstofvlakke (veral
van fosfate en nitrate) in alle seisoene. Die Cyperus textilis Biesieveld-gemeenskap is geassosieer met lae nitraat- en hoë fosfaatvlakke. Die Juncus effusus Biesieveldgemeenskap
vertoon die hoogste fosfaatvlakke, tydens die die somermaande, terwyl die
nitraatvlakke deur al die seisoene ook laag bly.
Opgeloste suurstof in die naby-oppervlakte water in die vleilandsisteem het
deurgaans ‘n lae konsentrasie vertoon met geen betekenisvolle verskille tussen
gemeenskappe nie. Dit speel dus geen belangrike rol in die voorkoms of verspreiding
van die plantgemeenskappe nie
Die meeste van hierdie faktore, gemeet om die waterkwaliteit te bepaal, het
veelvoudige, komplekse verhoudingsverskille, gebaseer veral op konsentrasieverskille,
tussen die gemeenskappe.
Ten spyte van die komplekse verwantskap tussen die plantgemeenskappe en
omgewingsfaktore, is die spesierykheid laag en kom die neiging tot eensoortigedominansie
algemeen in die vleiland-plantgemeenskappe voor. Die sterk assosiasie
tussen die plantgemeenskappe en bepaalde omgewingsveranderlikes voeg aansienlike
waarde daaraan toe om vleilandplantegroei te gebruik as indikator van vleilandtoestand.
‘n Poging om die verwantskappe tussen vleiland-plantgemeenskappe en
omgewingsveranderlikes algemeen te bepaal, sal die gebruikersvriendelike nut van
vleiland-plantgemeenskappe vir vleilandmonitering en assessering duidelik uitwys.
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Knowledge and use of traditional medicinal plants by the Setswana-speaking community of Kimberley, Northern Cape of South AfricaMonakisi, Charlotte M. 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The majority of South Africans still depend on the use of traditional remedies, as these
are sometimes the only types of health care systems available, especially within rural
communities. South Africa comprises approximately 400 000 traditional healers and an
estimated 60 to 80% of individuals consulting such traditional healers. As a result, the
over-harvesting of many traditional medicinal plants has become a threat to the country’s
species diversity and has resulted in the scarcity of certain medicinal plant species.
The non-sustainable use of traditional medicinal plants stems from their intense
harvesting from the wild to supply the high demands from urban and rural markets. As a
result of the escalating population growth rate; high rural unemployment; and
fundamental value attached to traditional medicinal plants (socio-economic factors), the
national and regional trade of traditional medicines is currently higher than it has ever
been. Another reason for the increased threat to traditional medicinal plants is the
degradation and weakening of customary laws that have previously regulated such
resources.
This study focuses on the use of traditional medicinal plants by the Setswana-speaking
community for self-medication and as a form of primary health care. Research was
conducted in Kimberley, Northern Cape of South Africa and focuses on the issue of the
sustainability of medicinal plant use in the area, specifically on use and users as well as
the acquisition of material sold by a single trader and harvesting techniques. This is to
determine whether harvesting of medicinal plants is a potential threat to plant
communities in the area. To address the shortcomings of medicinal anthropology the
study also investigates the impacts of relocation and resettlement of various communities
in the area, on plant use, methods of collection, the sustainability of the natural resource,
as well as the transmission of Setswana indigenous knowledge inter-generationally.
most abundant under high disturbances. Certain species reacted positively to disturbance
and were most abundant in disturbed habitats. These included Elephantorrhiza
elephantina and a Helichrysum sp.
To minimise destructive harvesting in the Kimberley area and to ensure the sustainable
harvesting of plant material, it is important that local harvesters are educated on proper
harvesting techniques and that local gatherers are educated on sustainability issues as
well as other ecologically fundamental issues. / AFRIKAANSE OPSOMMING: Die meeste Suid-Afrikaners is steeds afhanklik van tradisionele geneesmiddels aangesien
dit soms, veral in landelike gemeenskappe, die enigste beskikbare gesondheidsorg is.
Suid-Afrika het sowat 400 000 tradisionele geneeshere wat deur ’n geraamde 60% tot
80% van individue geraadpleeg word. As gevolg hiervan hou die oorontginning van talle
tradisionele medisinale-planthulpbronne ’n bedreiging vir die land se spesiediversiteit in
en het dit reeds tot ’n skaarste aan sekere medisinale plante gelei.
Tradisionele medisinale plante word tans nievolhoubaar aangewend aangesien dit op
groot skaal in die veld geoes word om in die groot vraag van stedelike en landelike
markte te voorsien. As gevolg van die stygende bevolkingsgroeikoers, hoë landelike
werkloosheidsyfer en die grondliggende waarde wat aan tradisionele medisinale plante
geheg word (sosio-ekonomiese faktore), is die nasionale en streekhandel in tradisionele
geneesmiddels tans groter as ooit tevore. Nog ’n rede vir die toenemende bedreiging van
tradisionele medisinale plante is die verslapping en versagting van gewoonteregwetgewing
wat voorheen sodanige hulpbronne gereguleer het.
Hierdie studie fokus op die gebruik van tradisionele medisinale plante deur die Setswanagemeenskap
vir selfbehandeling en as ’n vorm van primêre gesondheidsorg. Die
navorsing vir die studie is in Kimberley in die Noord-Kaapprovinsie van Suid-Afrika
gedoen en fokus op die kwessie van volhoubare medisinale-plantgebruik in die gebied,
met bepaalde klem op gebruik en gebruikers, die verkryging van middels wat deur ’n
enkele handelaar verkoop word, en oestegnieke. Die doel van die navorsing was om te
bepaal of die oes van medisinale plante ’n moontlike bedreiging vir plantgemeenskappe
in die gebied inhou. Om die tekortkominge van medisinale antropologie aan te pak,
ondersoek die studie ook die uitwerking van die verskuiwing en hervestiging van
verskeie gemeenskappe in die gebied op plantgebruik, oesmetodes, die volhoubaarheid
van die natuurlike hulpbronne, asook die oordrag van inheemse Setswana-kennis oor
geslagte heen. Selfbehandeling en die gebruik van tradisionele medisinale plante speel steeds ’n groot
rol in Kimberley, aangesien die meeste van die individue wat aan die navorsing
deelgeneem het steeds tradisionele geneesmiddels as deel van hulle kultuur en tradisie
gebruik. Daar word in ’n uiteenlopende verskeidenheid plantmateriaal handel gedryf.
Hoewel sommige van die middels plaaslik ingesamel word, word die meeste van ander
dele van die land, en in party gevalle van buurlande soos Lesotho en Swaziland,
ingevoer. Hoewel die meeste van die materiaal dus nie plaaslik ingesamel word en dus
nie bepaald op hierdie studie betrekking het nie, is dit steeds aanduidend van oes- en
volhoubaarheidskwessies in ander dele van die land.
Die kruiekenner dryf in sewentig tradisionele medisinale-plantsoorte handel, waarvan
party beskermd en erg bedreig is, waaronder Prunus africana en Warburgia salutaris wat
slegs in beskermde gebiede in die land voorkom. Prunus africana is ’n gelyste spesie in
CITES, aanhangsel 2. Ander bedreigde spesies sluit Ocotea bullata, Bersama lucens,
Curtisia dentata en ’n Eugenia-spesie in.
Die meeste van die plante wat (in Kimberley) geoes word, is in die vorm van
ondergrondse bergingsorgane (uitlopers en bolle). Hoewel hierdie plante van stingelskade
en die skade aan ondergrondse bergingsorgane kan herstel, vat hulle swak pos indien
hulle oorgebruik en oorontgin word, en kan hulle dus mettertyd al hoe minder voorkom.
In hierdie studie word die mettertydse afname in plantbevolkings deur die toename in
reisafstande na insamelingspunte aangetoon. Hierdie tendens is egter nie in die
handelsprys en -materiaalhoeveelhede oor die afgelope eeu weerspieël nie. Die meeste
van die studiedeelnemers het bevestig dat die prys en hoeveelheid van die
handelsmateriaal deurentyd betreklik stabiel gebly het.
Van die teikenspesies wat vir kwesbaarheid of sensitiwiteit vir ontwrigting ondersoek is,
het Withania somnifera, Boophane disticha, Dicoma anomala en Bulbine natalensis die
laagste oorlewingspotensiaal en die hoogste ontwrigtingsensitiwiteit getoon. Die meeste
van hierdie spesies het in baie klein hoeveelhede op die gekose terreine voorgekom. In
die geval van Withania somnifera kon die negatiewe resultate egter met die laereënvalseisoen gedurende daardie betrokke jaar in verband gebring word. Hierdie
spesie word oor die algemeen as ’n onkruid in ontwrigte gebiede geklassifiseer en kom
meestal onder erg ontwrigte toestande voor. Sekere spesies, soos Elephantorrhiza
elephantina en ’n Helichrysum-spesie, het positief op ontwrigting gereageer en het volop
in ontwrigte habitatte voorgekom.
Om vernietigende oestery in die Kimberley-omgewing te minimaliseer en die volhoubare
ontginning van planthulpbronne te verseker, is dit belangrik dat plaaslike plukkers in
gepaste oestegnieke, en plaaslike insamelaars oor volhoubaarheidskwessies en ander
ekologies belangrike sake opgelei word.
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An assessment of water quality and endocrine disruption activities in the Eerste/Kuils River catchment system, Western Cape, South AfricaFourie, Shani 04 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Water quality analysis forms the basis in assessing and monitoring catchments. As
urban development continuously increase, pollution sources increase in either point
source (wastewater treatment works, industrial effluents) and/or non-point source
origin (storm water discharge, domestic pollutants), accumulating pollutants in the
environment. It was only recently discovered that certain pollutants have subtle
disrupting effects on the endocrine system resulting in health related problems
associated with the reproductive system and thyroid system (growth and
development) of animals and potentially humans. Natural water resource
management proves to include limited biological assays measuring endpoints for
cytoxicity, inflammatory activity and endocrine disruption. The broad objective of
this study was therefore to include several bioassays, not normally used in municipal
(City of Cape Town) monitoring programmes, along with water quality data collected
by the City of Cape Town. The Eerste/Kuils River catchment system, Western Cape,
under the auspices of the City of Cape Town was chosen, and although this catchment
does not contribute to drinking water resources, is subjected to a range of
anthropogenic influences (industrial effluents, household wastewater, agricultural
runoff). Within the short time-frame available for this study (six months) two months,
July (following a dry summer and autumn season) and October (following a wet
winter and early spring season) were selected for water quality monitoring. Spatial
variation (with relevance to specific point and non-point contamination) among
sampling sites were also obtained by choosing several (n=10) along the catchment.
Specific aim of the study therefore included: Firstly (Chapter 2), the use of in vitro
bioassays, lactate-dehydrolises assay (LDH) for cytotoxic activity, pro-inflammatory
hormone Interleukin-6 (IL-6) secretion by human blood cells and a specific
Salmonella ELISA for faecal contamination, in conjunction with routine chemical and
biological (mostly microbiological) monitoring activities. The study indicated
significant variation among sites in all microbiological measures as well in IL-6
secretion and Salmonella presence. Between months, variations were also evident in
certain variables. Secondly (Chapter 3), two bioassays using the yolk precursor
protein, vitellogenin (Vtg) as endpoint was implemented in a) an in vitro Xenopus
laevis liver slice assay (five day exposure) and b) an in vivo Zebrafish (Danio rerio)
bioassay (seven day exposure) assessing estrogenic activity in the Eerste/Kuils River catchment. Although estrogen spiked positive control water samples stimulated Vtg
production in vitro as well as in vivo, no dramatic estrogenic activity was measured at
any of the selected sites. Thirdly (Chapter 4), a bioassay using the thyroid controlled
metamorphosis in Xenopus laevis tadpoles to assess effects on the thyroid hormonal
system was implemented. Thyroid stimulatory activity, compared with a negative
control sample, was measured at two sites along the catchment. Although the
practical implementation of the tadpole semi-static exposure protocol (water
replacement) proved to be labour intensive, all the added bioassays proved to be
valuable tools to add valuable information regarding water quality. It is clear that
more research related to anthropogenic influences along the Eerste/Kuils River
catchment system are needed, specifically in monitoring monthly variations to better
understand annual variation in several of the endpoints studied. / AFRIKAANSE OPSOMMING: Waterkwaliteit vorm die basis vir die evaluering en monitering van opvangsgebiede.
Voortdurende stedelike ontwikkeling gee aanleiding tot ‘n toename in die voorkoms
van besoedelstowwe in die natuurlike omgewing deur gelokaliseerde (punt) bronne
(rioolwerke/industriële uitvloeisel) en/of nie gelokaliseerde (nie punt) bronne (vloed
uitlaat/huishoudelike uitvloeisels) van besoedeling. Dit het onlangs aan die lig gekom
dat van hierdie chemise besoedelstowwe subtiel die endokriene sisteem versteur en so
aanleiding gee tot gesondheidsprobleme in terme van die voortplantingsisteem en
tiroied sisteem (groei en ontwikkeling) by diere en moontlik ook die mens. Daar is
beperkte gebruik van biologiese toetse wat inligting verskaf oor sitotoksiteit,
inflammatoriese aktiwiteit en endokriene versteuring. Die doel van hierdie studie was
dus om van hierdie biologiese toetse, wat normaalweg nie deel uitmaak van die
roetine munisipale (Stad van Kaapstad) opvangsgebied monitering nie, gebruik te
maak. Die Eerste-, Kuilsrivier, Wes Kaap, onder beheer van Stad Kaapstad is gekies
en alhoewel die opvangsgebied nie water bydra tot drinkwaterbronne nie, word die
opvangsgebied beïnvloed deur verskeie mensgemaakte bronne van besoedeling
(afloop vanuit omliggende lanbougebiede). Binne die kort tydsraamwerk van die
projek (ses maande) is besluit om twee maande, Julie (volg ‘n droë somer en herfs
seisoen) en Oktober (volg ‘n nat winter en vroeë lente seisoen) vir water kwaliteit
monitering te kies. Ruimtelike variasie langs die loop van die opvangsgebied is
ingesluit deur moniteringspunte (n=10), met in ag name van die potensiële
besoedelingsbronne. Spesifieke doelwitte van die projek sluit in: Eerstens (Hoofstuk
2), om die in vitro biotoetse, laktaat hidrolise (LDH) vir sitotoksisiteit, proinflammatoriese
hormoon Interleuikin-6 (IL-6) vir inflammatoriese aktiwiteit,
vrygestel deur menslike bloedselle en ‘n Salmonella ELISA vir ontlasting besoedeling
saam met bestaande chemise en biologiese (hoofsaaklik migrobiologiese)
veranderlikes te gebruik. Die studie het getoon dat beduidende variasie in alle
mikrobiologiese toetse asook IL-6 vrystelling en Salmonella voorkoms bestaan het
tussen versamelpunte. Maandelikse variasie in sekere van die veranderlikes het ook
voorgekom. Tweedens (Hoofstuk 3), is twee biotoetse wat die
dooiervoorloperproteïen, vitellogeen (Vtg) as eindpunt gebruik geimplimenteer in a)
‘n in vitro Xenopus laevis lewersnit biotoets (vyf dag blootstelling) en b) ‘n in vivo
Zebravis (Danio rerio) biotoets (sewe dag blootstelling) om estrogenisiteit in die Eerste-, Kuilsrivier opvangsgebied te evalueer. Alhoewel, die estrogeen behandelde
positiewe kontrole water monsters Vtg produksie veroorsaak het in beide die in vitro
lewer-kulture en in vivo vistoets, is geen dramatiess estrogeniese aktiwiteit by enige
van die moniteringspunte gevind nie. Derdens (Hoofstuk 4), is ‘n biotoets wat die
tiroïedbeheerde metamorfose in Xenopus laevis paddavisse gebruik om effekte op die
tiroïedsisteem te evalueer. Die differensiële stimulering (versnelling), in vergelyking
met ‘n negatiewe kontrole watermonster, van die tiroied sisteem is by twee
moniteringspunte in die opvangsgebied waargeneem. Alhoewel die praktiese
implementering van die paddavis semi-statiese (water word gereeld vervang) biotoets
arbeidsintensief is, het alle bykomstige biotoetse waardevolle bykomstige inligting
oor water kwaliteit verskaf wat ‘n belangrike bydrae tot ingeligte bestuursbesluite kan
verleen. Dit is duidelik dat meer navorsing int verband met die menslike invloed
langs die Eerste-, Kuilsrivier opvangsgebied nodig is, veral met maandlikse
monitering vir seisoenale veranderinge.
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