Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation

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dc.contributor.advisorLucas, Michael Ien_ZA
dc.contributor.advisorRawlings , Douglas Een_ZA
dc.contributor.advisorBranch, George Men_ZA
dc.contributor.authorTibbles, Brian Jonathanen_ZA
dc.date.accessioned2016-08-24T12:59:20Z
dc.date.available2016-08-24T12:59:20Z
dc.date.issued1994en_ZA
dc.description.abstractHeterotrophic bacterial activity and nitrogen fixation are fundamental to nutrient regeneration and nitrogen cycling in saltmarsh ecosystems. Ecological and physiological aspects of bacterial production and nitrogenase activity in marine sediments and water were examined in Langebaan Lagoon, a temperate saltmarsh ecosystem. Emphasis was placed on factors modulating rates and patterns of nitrogen fixation. Nitrogen fixation appeared to be dominated by heterotrophic bacteria. Rates of nitrogen fixation (estimated by the acetylene reduction technique), and bacterial production (estimated by tritiated thymidine incorporation, Tri) were higher in fine, muddy sediments near the head of the lagoon (Geelbek) than in coarser, sandy sediments near the mouth of the lagoon (Oesterwal). These comparisons (between sites) reflected the higher bacterial abundance and organic content of sediments from Geelbek. Examinations of five sedimentary microhabitats at each site (including those associated with beds of the seagrass Zostera capensis, burrows of the sandprawn Callianassa kraussi at Oesterwal, and burrows of the mudprawn Upogebia africana at Geelbek) showed that bacterial activity was higher in surface sediments than in subsurface sediments. Highest rates of nitrogen fixation (annual mean, 0.28 + 0.07 nmol C2H4 g-1 dry sediment h-1) were measured in Zostera bed sediments at Geelbek. Thymidine incorporation activity and nitrogenase activity were higher in burrow linings than in adjacent subsurface sediments, suggesting that burrow linings provided an improved subsurface environment for bacterial activity. Burrow linings also had a higher organic content than subsurface sediments away from burrows. Nitrogenase activity was not detected in lagoon water.en_ZA
dc.identifier.apacitationTibbles, B. J. (1994). <i>Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/21512en_ZA
dc.identifier.chicagocitationTibbles, Brian Jonathan. <i>"Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1994. http://hdl.handle.net/11427/21512en_ZA
dc.identifier.citationTibbles, B. 1994. Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Tibbles, Brian Jonathan AB - Heterotrophic bacterial activity and nitrogen fixation are fundamental to nutrient regeneration and nitrogen cycling in saltmarsh ecosystems. Ecological and physiological aspects of bacterial production and nitrogenase activity in marine sediments and water were examined in Langebaan Lagoon, a temperate saltmarsh ecosystem. Emphasis was placed on factors modulating rates and patterns of nitrogen fixation. Nitrogen fixation appeared to be dominated by heterotrophic bacteria. Rates of nitrogen fixation (estimated by the acetylene reduction technique), and bacterial production (estimated by tritiated thymidine incorporation, Tri) were higher in fine, muddy sediments near the head of the lagoon (Geelbek) than in coarser, sandy sediments near the mouth of the lagoon (Oesterwal). These comparisons (between sites) reflected the higher bacterial abundance and organic content of sediments from Geelbek. Examinations of five sedimentary microhabitats at each site (including those associated with beds of the seagrass Zostera capensis, burrows of the sandprawn Callianassa kraussi at Oesterwal, and burrows of the mudprawn Upogebia africana at Geelbek) showed that bacterial activity was higher in surface sediments than in subsurface sediments. Highest rates of nitrogen fixation (annual mean, 0.28 + 0.07 nmol C2H4 g-1 dry sediment h-1) were measured in Zostera bed sediments at Geelbek. Thymidine incorporation activity and nitrogenase activity were higher in burrow linings than in adjacent subsurface sediments, suggesting that burrow linings provided an improved subsurface environment for bacterial activity. Burrow linings also had a higher organic content than subsurface sediments away from burrows. Nitrogenase activity was not detected in lagoon water. DA - 1994 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1994 T1 - Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation TI - Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation UR - http://hdl.handle.net/11427/21512 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21512
dc.identifier.vancouvercitationTibbles BJ. Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1994 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/21512en_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.otherZoologyen_ZA
dc.titleEcology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixationen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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