Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys

 

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dc.contributor.advisor Field, John G en_ZA
dc.contributor.advisor Champion, Harold en_ZA
dc.contributor.author Coetzee, Janet Claire en_ZA
dc.date.accessioned 2016-05-24T09:15:19Z
dc.date.available 2016-05-24T09:15:19Z
dc.date.issued 1997 en_ZA
dc.identifier.citation Coetzee, J. 1997. Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/19818
dc.description Bibliography: pages 113-117. en_ZA
dc.description.abstract The total allowable catches (TA Cs) of both anchovy and sardine in South Africa are determined by assessment methods which rely on absolute estimates of recruitment and spawner biomass each year. The validity of the TAC set for each species each year is heavily dependent on the accuracy and precision of the biomass estimates. The method used for both anchovy and sardine has been acoustic surveys on a random stratified grid covering the known range of the species. These surveys have, however, been designed according to the life history patterns of anchovy, which result in a particular occupation of the pelagic environment. This study investigated the shoaling dynamics of sardine at various scales in both the horizontal and vertical dimension in an attempt to ascertain whether these surveys are adequate to characterise the occupation of space by sardine. Hydro-acoustic data collected during 5 meso-scale surveys in 1994 and 1995 was used to study the shoaling dynamics of sardine, Sardinops sagax on the western Agulhas Bank of South Africa. Results of this study indicate the presence of spatial structure in sardine aggregations at both the shoal and meso-scale level. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Biological Sciences en_ZA
dc.title Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys en_ZA
dc.type Master 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 Masters
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Coetzee, J. C. (1997). <i>Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/19818 en_ZA
dc.identifier.chicagocitation Coetzee, Janet Claire. <i>"Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1997. http://hdl.handle.net/11427/19818 en_ZA
dc.identifier.vancouvercitation Coetzee JC. Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 1997 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/19818 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Coetzee, Janet Claire AB - The total allowable catches (TA Cs) of both anchovy and sardine in South Africa are determined by assessment methods which rely on absolute estimates of recruitment and spawner biomass each year. The validity of the TAC set for each species each year is heavily dependent on the accuracy and precision of the biomass estimates. The method used for both anchovy and sardine has been acoustic surveys on a random stratified grid covering the known range of the species. These surveys have, however, been designed according to the life history patterns of anchovy, which result in a particular occupation of the pelagic environment. This study investigated the shoaling dynamics of sardine at various scales in both the horizontal and vertical dimension in an attempt to ascertain whether these surveys are adequate to characterise the occupation of space by sardine. Hydro-acoustic data collected during 5 meso-scale surveys in 1994 and 1995 was used to study the shoaling dynamics of sardine, Sardinops sagax on the western Agulhas Bank of South Africa. Results of this study indicate the presence of spatial structure in sardine aggregations at both the shoal and meso-scale level. DA - 1997 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1997 T1 - Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys TI - Acoustic investigation of the shoaling dynamics of sardine sardinops sagax populations : implications for acoustic surveys UR - http://hdl.handle.net/11427/19818 ER - en_ZA


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