Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa

 

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dc.contributor.advisor Branch, George M en_ZA
dc.contributor.advisor Pillay, Deena en_ZA
dc.contributor.advisor Von der Heyden, Sophie en_ZA
dc.contributor.author Zeeman, Susanna Catharina Franzina en_ZA
dc.date.accessioned 2016-07-20T12:35:00Z
dc.date.available 2016-07-20T12:35:00Z
dc.date.issued 2016 en_ZA
dc.identifier.citation Zeeman, S. 2016. Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/20542
dc.description.abstract Invasive species can radically affect community composition and ecosystem processes, and human traffic has accelerated their spread. On the South African coast, 86 invasive species have been recorded, although until recently only the Mediterranean mussel Mytilus galloprovincialis and the barnacle Balanus glandula have had significant ecosystem effects on a large geographic scale. Semimytilus algosus was first detected at Elands Bay in 2009 and by 2010 it occupied 500 km of the West Coast of South Africa from Groenriviermond to Bloubergstrand. Given the fact that it is an ecosystem engineer forming dense beds, it is likely to have marked community effects. My study aimed to determine: (A) the identity, genetic composition and origin of the population, and (B) potential interactions between M. galloprovincialis and S. algosus and their effects on community composition. I conducted surveys to assess the abundance and zonation of S. algosus, analysed its competitive abilities by comparing its life-history strategies to other mussel species on the West Coast, and conducted field experiments to examine survival and interactions between S. algosus and M. galloprovincialis at different shore heights. I confirmed the identity of this species and found that the South African population has comparable genetic variation to the Chilean and Namibian populations. It spread to South Africa, seemingly through larval dispersal from Namibia, and now ranges from Groenriviermond in the north to Hout Bay in the south, spreading southward. It is most abundant on the low shore, with M. galloprovincialis on the mid shore. Mixed beds co-exist in the transition zone. Biodiversity in S. algosus beds is similar to that in M. galloprovincialis beds. High recruitment rates of S. algosus on the low shore, and its high genetic variation at all sites, enable it to colonise rock quickly and become established in new areas. The competitive ability of Semimytilus algosus is strongly related to shore height. It cannot survive on the high shore due to intolerance to desiccation. On the low shore its high recruitment rate offsets its high mortality due to wave action and predation. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Biological Sciences en_ZA
dc.title Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa en_ZA
dc.type Doctoral Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Biological Sciences en_ZA
dc.type.qualificationlevel Doctoral
dc.type.qualificationname PhD en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Zeeman, S. C. F. (2016). <i>Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/20542 en_ZA
dc.identifier.chicagocitation Zeeman, Susanna Catharina Franzina. <i>"Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2016. http://hdl.handle.net/11427/20542 en_ZA
dc.identifier.vancouvercitation Zeeman SCF. Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/20542 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Zeeman, Susanna Catharina Franzina AB - Invasive species can radically affect community composition and ecosystem processes, and human traffic has accelerated their spread. On the South African coast, 86 invasive species have been recorded, although until recently only the Mediterranean mussel Mytilus galloprovincialis and the barnacle Balanus glandula have had significant ecosystem effects on a large geographic scale. Semimytilus algosus was first detected at Elands Bay in 2009 and by 2010 it occupied 500 km of the West Coast of South Africa from Groenriviermond to Bloubergstrand. Given the fact that it is an ecosystem engineer forming dense beds, it is likely to have marked community effects. My study aimed to determine: (A) the identity, genetic composition and origin of the population, and (B) potential interactions between M. galloprovincialis and S. algosus and their effects on community composition. I conducted surveys to assess the abundance and zonation of S. algosus, analysed its competitive abilities by comparing its life-history strategies to other mussel species on the West Coast, and conducted field experiments to examine survival and interactions between S. algosus and M. galloprovincialis at different shore heights. I confirmed the identity of this species and found that the South African population has comparable genetic variation to the Chilean and Namibian populations. It spread to South Africa, seemingly through larval dispersal from Namibia, and now ranges from Groenriviermond in the north to Hout Bay in the south, spreading southward. It is most abundant on the low shore, with M. galloprovincialis on the mid shore. Mixed beds co-exist in the transition zone. Biodiversity in S. algosus beds is similar to that in M. galloprovincialis beds. High recruitment rates of S. algosus on the low shore, and its high genetic variation at all sites, enable it to colonise rock quickly and become established in new areas. The competitive ability of Semimytilus algosus is strongly related to shore height. It cannot survive on the high shore due to intolerance to desiccation. On the low shore its high recruitment rate offsets its high mortality due to wave action and predation. DA - 2016 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa TI - Genetics and ecosystem effects of the invasive mussel Semimytilus algosus, on the West Coast of South Africa UR - http://hdl.handle.net/11427/20542 ER - en_ZA


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