Princess Vlei : what diatoms can tell us about spatial and temporal heterogeneity in an urban wetland

Content Provider	Semantic Scholar
Author	Cowan, Oliver
Copyright Year	2010
Abstract	Globally, wetlands are being degraded and destroyed largely as a result of anthropogenic activity. Monitoring and assessment are required to maintain functional ecosystems and the valuable services they provide. Surface sediment cores were taken from 4 points around an urban wetland (Princess Vlei) on the Cape Flats, Cape Town, South Africa. Diatoms were and used as a proxy for water quality variables to determine whether the diatom flora preserved in organic sediments accumulating in and around an urban wetland is a useful tool in determining the changes in water quality over time. In addition, the project attempts to establish whether there are spatial patterns in diatom flora within a small lake. Diatoms from three depths from each of the four sites were identified, counted and analyzed according to their trophic preferences and pollution tolerances which were acquired from a variety of resources. Results showed clear spatial differences between sites as a result of positioning in relation to effluent input, output and specific site characteristics such as reed stands. Differences between depths were evident although no significant trends were observed. In summation; spatial heterogeneity in the diatom assemblage of an urban wetland reveal that diatoms are suitable indicators of water quality, even within a small system, due to their niche specificity. The project also shows that Princess Vlei remains a eutrophic and polluted wetland, although not uniformly so. Continual monitoring is required to prevent the vlei from becoming a health hazard for the surrounding community and to maintain its ability to act as a buffering zone to protect the Rondevlei nature reserve, as well as acting as a functional ecosystem in an area threatened by urbanization.
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://open.uct.ac.za/bitstream/handle/11427/24854/thesis_sci_2010_cowan_oliver.pdf?sequence=1
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article