Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape

dc.contributor.advisorAnderson, Robert Jen_ZA
dc.contributor.authorDrummond, Hazelen_ZA
dc.date.accessioned2017-10-11T10:47:12Z
dc.date.available2017-10-11T10:47:12Z
dc.date.created2001
dc.date.issued2001en_ZA
dc.date.updated2017-02-08T08:47:14Z
dc.description.abstractThe demand for freshly harvested kelp, Ecklonia maxima, in the Western Cape, has greatly increased due to the need for fodder to supply the growing abalone industry. There is evidence suggesting that the present demand may exceed the amount of E. maxima available, if the traditional method of harvesting continues (cutting the whole kelp plant off, just above the holdfast). There is also evidence that, although the kelp beds recover in 2 - 3 years, and are ready for the next harvesting event, the epiphytic seaweed populations have not recovered even 5 years after harvesting. A new method of harvesting has been proposed, where the secondary blades of the E. maxima are cut 30cm from the primary blade. This method would increase the amount of kelp that can be harvested sustainably. This study investigated whether this new method of harvesting would have less impact on the epiphytic seaweed populations, particularly the three obligate epiphyte species; Carpoblepharis flaccida, Polysiphonia virgata and Suhria vittata, and whether there is pattern of distribution of epiphyte populations around the Cape Peninsula. The distribution of the epiphytes on the different portions (stipe; primary blade and first 30cm of secondary blades; rest of the secondary blades) of kelp was investigated. E.maxima was sampled at five sites around the Cape Peninsula, and the epiphytes on each portion were identified and weighed. All the epiphytes except Carpoblepharis flaccida were found predominantly on the portion of kelp that would be left after the new method of harvesting, and would therefore be unaffected. It was found that the mass of C.flaccida removed in the new method was not significantly different from the mass remaining; therefore a large proportion is left untouched. There was no geographic pattern of distribution of C.flaccida in relation to water temperature around the Cape Peninsula. The results suggest that this new method of harvesting would have little impact on the epiphyte populations, which is an added incentive for changing the method of harvesting.en_ZA
dc.identifier.apacitationDrummond, H. (2001). <i>Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/25563en_ZA
dc.identifier.chicagocitationDrummond, Hazel. <i>"Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2001. http://hdl.handle.net/11427/25563en_ZA
dc.identifier.citationDrummond, H. 2001. Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Drummond, Hazel AB - The demand for freshly harvested kelp, Ecklonia maxima, in the Western Cape, has greatly increased due to the need for fodder to supply the growing abalone industry. There is evidence suggesting that the present demand may exceed the amount of E. maxima available, if the traditional method of harvesting continues (cutting the whole kelp plant off, just above the holdfast). There is also evidence that, although the kelp beds recover in 2 - 3 years, and are ready for the next harvesting event, the epiphytic seaweed populations have not recovered even 5 years after harvesting. A new method of harvesting has been proposed, where the secondary blades of the E. maxima are cut 30cm from the primary blade. This method would increase the amount of kelp that can be harvested sustainably. This study investigated whether this new method of harvesting would have less impact on the epiphytic seaweed populations, particularly the three obligate epiphyte species; Carpoblepharis flaccida, Polysiphonia virgata and Suhria vittata, and whether there is pattern of distribution of epiphyte populations around the Cape Peninsula. The distribution of the epiphytes on the different portions (stipe; primary blade and first 30cm of secondary blades; rest of the secondary blades) of kelp was investigated. E.maxima was sampled at five sites around the Cape Peninsula, and the epiphytes on each portion were identified and weighed. All the epiphytes except Carpoblepharis flaccida were found predominantly on the portion of kelp that would be left after the new method of harvesting, and would therefore be unaffected. It was found that the mass of C.flaccida removed in the new method was not significantly different from the mass remaining; therefore a large proportion is left untouched. There was no geographic pattern of distribution of C.flaccida in relation to water temperature around the Cape Peninsula. The results suggest that this new method of harvesting would have little impact on the epiphyte populations, which is an added incentive for changing the method of harvesting. DA - 2001 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2001 T1 - Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape TI - Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape UR - http://hdl.handle.net/11427/25563 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/25563
dc.identifier.vancouvercitationDrummond H. Distribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Cape. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2001 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/25563en_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.otherBotanyen_ZA
dc.titleDistribution and biomass of epiphytic seaweeds on the kelp Ecklonia maxima (Osbeck) Papenfuss, and the potential effects of two kelp-harvesting methods in the Western Capeen_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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