Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2017 / In this study data was collected to establish if the water and sediment quality of the
Steelpoort River has any effects on macro-invertebrate species. The Steelpoort River
is a tributary of the Olifants River system but not much data about the water quality is
available. The Steelpoort River is a perennial river (Ashton et al. 2001) situated west
of Burgersfort and from there it flows in a north- easterly direction and converges
with the Olifants River in the Drakensberg near Kromellenboog. High silt levels in the
river, increases the risk of flooding and leads to the smothering of in-stream habitats
resulting in loss of some invertebrate and fish species.
Sampling of the water, sediment and macroinvertebrates was conducted quarterly at
the Steelpoort River at five sites. One site was above the impoundment (De Hoop
Dam) and the rest were below the impoundment. A handheld YSI 556™ Multi Probe
System (MPS instrument and a Mettler Toledo SevenGo™ conductivity meter were
used to measure the physico-chemical characteristics at the sites. The
macroinvertebrates were sampled using the SASS 5 bio-assessment protocol
(Goodyear & McNeill 1999, Dickens & Graham 2002). Macro-invertebrate samples
were collected using a 400 mm x 400 mm SASS net with a 250 μm mesh size. The
substrate was disturbed for a period of two minutes to free macro-invertebrates from
the substrate. The SASS score for each site was evaluated in the field for three of
the five samples. The macro-invertebrate samples were preserved in 70% ethanol
and sorted to family level in the University of Limpopo’s Biodiversity laboratory.
For the majority of the physico-chemical parameters the most elevated were
detected downstream and lowest concentrations were detected upstream. Analysis
of variance (ANOVA) indicated that there were no significant differences for electrical
conductivity, salinity, and TDS, between the sites (p>0.05). There were however
significant differences in the temperature, dissolved oxygen, turbidity, and pH
concentrations (p<0.05). The majority of the metals and metalloids in the water (Fe,
Mn, V, Co, Zn, Ba, and Cu) were highest at Tiershoek (Site1) and lowest at
Steelpoort (Site 4) and Burgersfort Bridge (Site 5).The mean metal concentrations
collected showed elevated levels for chromium, copper and zinc, which were above
the CCME sediment guidelines.
The most abundant macroinvertebrates were from the family Ephemeroptera which
are pollution sensitive and good indicators of pollution in aquatic ecosystems. When
using the interpretation of the SASS 5 results from Chutter 1995, the mean Average
Score Per Taxa (ASPT) scores show that the water quality for Tiershoek (Site 1) and
Polopark (Site 3) is natural but the habitat diversity has been reduced. For De Hoop
(Site 2) and Steelpoort (Site 4), the mean ASPT score shows that there is some
deterioration in the water quality. Finally, for Burgersfort Bridge (Site 5), the mean
ASPT score indicates that there is major deterioration in the water quality.
Primer statistical analysis indicated that the average dissimilarity between sites
showed that the highest dissimilarity was between Tiershoek (Site 1) and Burgersfort
Bridge (Site 5) which was conclusive with the results from the macro-invertebrate
count and SASS, indicating that there is diverse difference from upstream to
downstream.
CCA indicated positive correlations between nutrients detected at Steelpoort with
Athericidae, Tabanidae, Gomphidae, Baetidae, Elmidae, Planaria, Psephenidae, and
Libellulidae which was indicated that water chemistry characteristics exert influence
on macroinvertebrates. The results showed that there is degradation of the water
quality in river from upstream to downstream with more pollution tolerant species
being abundant at Steelpoort (Site 4) and Burgersfort Bridge (Site 5). The most
favourable season was autumn and the least summer/spring and this may be
attributed to the life cycle of the macro-invertebrate communities / NRF
VLIR
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ul/oai:ulspace.ul.ac.za:10386/4268 |
| Date | January 2017 |
| Creators | Matlou, Katlego Shirley |
| Contributors | Addo-Bediako, A., Jooste, A. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | xiii, 148 leaves |
| Relation |
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