Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa

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dc.contributor.authorKock, Alisonen_ZA
dc.contributor.authorO'Riain, M Justinen_ZA
dc.contributor.authorMauff, Katyaen_ZA
dc.contributor.authorMeÿer, Michaelen_ZA
dc.contributor.authorKotze, Deonen_ZA
dc.contributor.authorGriffiths, Charlesen_ZA
dc.date.accessioned2015-11-16T04:14:17Z
dc.date.available2015-11-16T04:14:17Z
dc.date.issued2013en_ZA
dc.description.abstractWhite sharks ( Carcharodon carcharias ) are threatened apex predators and identification of their critical habitats and how these are used are essential to ensuring improved local and ultimately global white shark protection. In this study we investigated habitat use by white sharks in False Bay, South Africa, using acoustic telemetry. 56 sharks (39 female, 17 male), ranging in size from 1.7-5 m TL, were tagged with acoustic transmitters and monitored on an array of 30 receivers for 975 days. To investigate the effects of season, sex and size on habitat use we used a generalized linear mixed effects model. Tagged sharks were detected in the Bay in all months and across all years, but their use of the Bay varied significantly with the season and the sex of the shark. In autumn and winter males and females aggregated around the Cape fur seal colony at Seal Island, where they fed predominantly on young of the year seals. In spring and summer there was marked sexual segregation, with females frequenting the Inshore areas and males seldom being detected. The shift from the Island in autumn and winter to the Inshore region in spring and summer by females mirrors the seasonal peak in abundance of juvenile seals and of migratory teleost and elasmobranch species respectively. This study provides the first evidence of sexual segregation at a fine spatial scale and demonstrates that sexual segregation in white sharks is not restricted to adults, but is apparent for juveniles and sub-adults too. Overall, the results confirm False Bay as a critical area for white shark conservation as both sexes, across a range of sizes, frequent the Bay on an annual basis. The finding that female sharks aggregate in the Inshore regions when recreational use peaks highlights the need for ongoing shark-human conflict mitigation strategies.en_ZA
dc.identifier.apacitationKock, A., O'Riain, M. J., Mauff, K., Meÿer, M., Kotze, D., & Griffiths, C. (2013). Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa. <i>PLoS One</i>, http://hdl.handle.net/11427/15036en_ZA
dc.identifier.chicagocitationKock, Alison, M Justin O'Riain, Katya Mauff, Michael Meÿer, Deon Kotze, and Charles Griffiths "Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa." <i>PLoS One</i> (2013) http://hdl.handle.net/11427/15036en_ZA
dc.identifier.citationKock, A., O’Riain, M. J., Mauff, K., Meÿer, M., Kotze, D., & Griffiths, C. (2013). Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa. PLoS One, 8(1), e55048. doi:10.1371/journal.pone.0055048en_ZA
dc.identifier.ris TY - Journal Article AU - Kock, Alison AU - O'Riain, M Justin AU - Mauff, Katya AU - Meÿer, Michael AU - Kotze, Deon AU - Griffiths, Charles AB - White sharks ( Carcharodon carcharias ) are threatened apex predators and identification of their critical habitats and how these are used are essential to ensuring improved local and ultimately global white shark protection. In this study we investigated habitat use by white sharks in False Bay, South Africa, using acoustic telemetry. 56 sharks (39 female, 17 male), ranging in size from 1.7-5 m TL, were tagged with acoustic transmitters and monitored on an array of 30 receivers for 975 days. To investigate the effects of season, sex and size on habitat use we used a generalized linear mixed effects model. Tagged sharks were detected in the Bay in all months and across all years, but their use of the Bay varied significantly with the season and the sex of the shark. In autumn and winter males and females aggregated around the Cape fur seal colony at Seal Island, where they fed predominantly on young of the year seals. In spring and summer there was marked sexual segregation, with females frequenting the Inshore areas and males seldom being detected. The shift from the Island in autumn and winter to the Inshore region in spring and summer by females mirrors the seasonal peak in abundance of juvenile seals and of migratory teleost and elasmobranch species respectively. This study provides the first evidence of sexual segregation at a fine spatial scale and demonstrates that sexual segregation in white sharks is not restricted to adults, but is apparent for juveniles and sub-adults too. Overall, the results confirm False Bay as a critical area for white shark conservation as both sexes, across a range of sizes, frequent the Bay on an annual basis. The finding that female sharks aggregate in the Inshore regions when recreational use peaks highlights the need for ongoing shark-human conflict mitigation strategies. DA - 2013 DB - OpenUCT DO - 10.1371/journal.pone.0055048 DP - University of Cape Town J1 - PLoS One LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa TI - Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa UR - http://hdl.handle.net/11427/15036 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/15036
dc.identifier.urihttp://dx.doi.org/10.1371/journal.pone.0055048
dc.identifier.vancouvercitationKock A, O'Riain MJ, Mauff K, Meÿer M, Kotze D, Griffiths C. Residency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africa. PLoS One. 2013; http://hdl.handle.net/11427/15036.en_ZA
dc.language.isoengen_ZA
dc.publisherPublic Library of Scienceen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en_ZA
dc.rights.holder© 2013 Kock et alen_ZA
dc.rights.urihttp://creativecommons.org/licenses/by/4.0en_ZA
dc.sourcePLoS Oneen_ZA
dc.source.urihttp://journals.plos.org/plosoneen_ZA
dc.subject.otherSharksen_ZA
dc.subject.otherAcousticsen_ZA
dc.subject.otherHabitatsen_ZA
dc.subject.otherSealsen_ZA
dc.subject.otherSouth Africaen_ZA
dc.subject.otherAnimal migrationen_ZA
dc.subject.otherCoastal regionsen_ZA
dc.subject.otherPredationen_ZA
dc.titleResidency, habitat use and sexual segregation of white sharks, Carcharodon carcharias in False Bay, South Africaen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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