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Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal
Includes bibliographical references.
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Department of Biological Sciences
2015
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| _version_ | 1867614479375663104 |
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| access_status_str | Open Access |
| author | Labinjoh, Lisa |
| author2 | Attwood, Colin |
| author_browse | Attwood, Colin Labinjoh, Lisa |
| author_facet | Attwood, Colin Labinjoh, Lisa |
| author_sort | Labinjoh, Lisa |
| collection | Thesis |
| description | Includes bibliographical references. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/13359 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:52:41.929Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | Department of Biological Sciences |
| publisherStr | Department of Biological Sciences |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/13359 Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal Labinjoh, Lisa Attwood, Colin Applied Marine Science Includes bibliographical references. This study estimates rates of shark depredation in the charter boat fishery on Protea Banks, KwaZulu-Natal. Previous estimates based on fisher surveys suggested that shark depredation is a concern locally and may distort fishing mortality estimates. Methods involved quantitative data collection by an onboard observer from November 2013 to January 2014. Catch composition data were collected to enable comparisons with the commercial and recreational catch returns used in monitoring and assessment. Results revealed an average depredation rate of 8.4% that varied depending on the species fishers targeted. Depredation was highest when catching pelagic species (18.6%) and lowest when catching reef species (1.9%). Depredation rates were highest in November (19.6%) and lowest in January (5.3%). Observed rates were highest on the Banks itself and immediately offshore (9.9%), but no depredation was observed inshore of the Banks. The most commonly identified sharks involved in depredation incidents were the dusky shark (Carcharhinus obscurus) and the blacktip shark (Carcharhinus limbatus). Multi-dimensional scaling showed commercial catch composition to be significantly different from recreational and charter catch composition, mainly due to abundance of tuna in the recreational and charter sectors. No significant relationship was found between catch composition and shark depredation. Depredation is estimated to cost charter fishing operators 8% of their revenue. Depredation rates are at a level that could impact effective stock assessment and should be considered when making management decisions. 2015-07-03T08:35:07Z 2015-07-03T08:35:07Z 2014 Master Thesis Masters MSc http://hdl.handle.net/11427/13359 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Applied Marine Science Labinjoh, Lisa Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal |
| thesis_degree_str | Master's |
| title | Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal |
| title_full | Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal |
| title_fullStr | Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal |
| title_full_unstemmed | Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal |
| title_short | Rates of shark depredation of line-caught fish on the Protea Banks, KwaZulu-Natal |
| title_sort | rates of shark depredation of line caught fish on the protea banks kwazulu natal |
| topic | Applied Marine Science |
| url | http://hdl.handle.net/11427/13359 |
| work_keys_str_mv | AT labinjohlisa ratesofsharkdepredationoflinecaughtfishontheproteabankskwazulunatal |