Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae

dc.contributor.advisorBolton, John Jen_ZA
dc.contributor.advisorHoffmann, Timmen_ZA
dc.contributor.authorMuhl, Saraen_ZA
dc.date.accessioned2017-10-23T06:28:29Z
dc.date.available2017-10-23T06:28:29Z
dc.date.issued2003en_ZA
dc.date.updated2017-02-22T12:51:41Z
dc.description.abstractZandvlei is a system that has been highly modified by the urban environment of Cape Town. Salinity is a major driver determining the physical environment of estuaries. The macroalgal community of estuaries forms an important part of the ecology of these systems as primary producers. The salinity of this environment is an important parameter determining the composition, abundance and diversity of these communities. Patterns of salinity fluctuations in the long term (1978-2003) and annually are described in order to establish how communities may vary. Zandvlei is in a Mediterranean climate and salinity was found to vary seasonally and monthly with fluctuations in rainfall. Historical records of macroalgae identified in the estuary were summarized and no record of the Polysiphonia sp., now dominant in the estuary, was found. Dominant macroalgae in the estuary were identified and grown under a range of salinities (0, 1, 5, 10, 20, 29 ppt). Dominant macroalgae included Cladophora sp., Polysiphonia sp. and Enteromorpha prolifera. None of these algae survived at O ppt. In 1 ppt E. prolifera survived but growth was retarded, Polysiphonia sp. survived but did not grow and Cladophora sp. grew successfully at this salinity. All three species have different optimum ranges for growth with E. prolifera preferring higher salinities, Cladophora sp. grew similarly across the range from 1 to 29 ppt and Polysiphonia sp. grew most rapidly at 5 ppt. Depending on the salinity range in the estuary different macroalgae will be dominant. This makes the macroalgae community quite resilient to fluctuating salinities. There should therefore always be estuarine macroalgae present in the estuary provided salinity does not drop below 1 ppt for an extended period. If salinities did drop below 1 ppt there could be an increase in freshwater algae.en_ZA
dc.identifier.apacitationMuhl, S. (2003). <i>Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/25721en_ZA
dc.identifier.chicagocitationMuhl, Sara. <i>"Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2003. http://hdl.handle.net/11427/25721en_ZA
dc.identifier.citationMuhl, S. 2003. Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Muhl, Sara AB - Zandvlei is a system that has been highly modified by the urban environment of Cape Town. Salinity is a major driver determining the physical environment of estuaries. The macroalgal community of estuaries forms an important part of the ecology of these systems as primary producers. The salinity of this environment is an important parameter determining the composition, abundance and diversity of these communities. Patterns of salinity fluctuations in the long term (1978-2003) and annually are described in order to establish how communities may vary. Zandvlei is in a Mediterranean climate and salinity was found to vary seasonally and monthly with fluctuations in rainfall. Historical records of macroalgae identified in the estuary were summarized and no record of the Polysiphonia sp., now dominant in the estuary, was found. Dominant macroalgae in the estuary were identified and grown under a range of salinities (0, 1, 5, 10, 20, 29 ppt). Dominant macroalgae included Cladophora sp., Polysiphonia sp. and Enteromorpha prolifera. None of these algae survived at O ppt. In 1 ppt E. prolifera survived but growth was retarded, Polysiphonia sp. survived but did not grow and Cladophora sp. grew successfully at this salinity. All three species have different optimum ranges for growth with E. prolifera preferring higher salinities, Cladophora sp. grew similarly across the range from 1 to 29 ppt and Polysiphonia sp. grew most rapidly at 5 ppt. Depending on the salinity range in the estuary different macroalgae will be dominant. This makes the macroalgae community quite resilient to fluctuating salinities. There should therefore always be estuarine macroalgae present in the estuary provided salinity does not drop below 1 ppt for an extended period. If salinities did drop below 1 ppt there could be an increase in freshwater algae. DA - 2003 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2003 T1 - Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae TI - Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae UR - http://hdl.handle.net/11427/25721 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/25721
dc.identifier.vancouvercitationMuhl S. Long-term salinity trends in Zandvlei estuary and implications for dominant macroalgae. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2003 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/25721en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherSystematics and Biodiversity Sciencesen_ZA
dc.subject.otherPlant Ecologyen_ZA
dc.titleLong-term salinity trends in Zandvlei estuary and implications for dominant macroalgaeen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetype
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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