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Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 10. The dusky shark Carcharhinus obscurus (Lesueur 1818)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SFJ Dudley G Cliff MP Zungu MJ SmaleBetween 1978 and 1999, a total of 5 626 dusky sharks Carcharhinus obscurus, constituting 20% of the total shark catch, was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 256 sharks (SD = 107.5,... -
Factors affecting recapture rates of raggedtooth sharks Carcharias taurus tagged off the east coast of South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: ML Dicken --- Department of Ichthyology and Fisheries Science, South Africa AJ Booth --- Department of Ichthyology and Fisheries Science, South Africa MJ Smale --- , South AfricaUnderstanding differences in the recapture rate between different tags (A-, B- and C-types), capture methods (rock-and-surf anglers, scientific divers and Natal Sharks Board protection nets) and life-history stages (juvenile and adult) is critical in evaluating the results obtained from cooperative... -
Movements and habitat utilization of nembwe, Serranochromis robustus (Günther, 1864), in the Upper Zambezi River
Item type: Journal Article • Journal: African Zoology • Authors: Eva B. Thorstad --- Norwegian Institute for Nature Research (NINA), Norway Clinton J. Hay --- Ministry of Fisheries and Marine Resources, Namibia Tor F. Næsje --- Norwegian Institute for Nature Research (NINA), Norway Ben Chanda --- Ministry of Agriculture and Co-operatives, Department of Research and Specialised Services, Zambia Finn Økland --- Norwegian Institute for Nature Research (NINA), NorwayFifteen adult nembwe Serranochromis robustus (Günther, 1864) were tagged with radio transmitters in the Zambezi River, Namibia, from 4–15 November 2000 to record behaviour and outline the implications for fisheries management. The fish were tracked on average every 3.7 days... -
Validation of growth zone deposition in otoliths of two large endemic cyprinids in Lake Gariep, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Henning Winker --- Department of Ichthyology and Fisheries Science, South Africa Bruce R. Ellender --- Department of Ichthyology and Fisheries Science, South Africa Olaf L.F. Weyl --- South African Institute for Aquatic Biodiversity, South Africa Anthony J. Booth --- Department of Ichthyology and Fisheries Science, South AfricaWe tested the hypothesis that growth zones in the astericus otoliths of smallmouth yellowfish (Labeobarbus aeneus) and Orange River mudfish (Labeo capensis) were deposited annually. Two methods, fluorochrome marking and edge analysis of otoliths were used. For fluorochrome marking, specimens... -
Growth rate of speckled snapper Lutjanus rivulatus (Teleostei: Lutjanidae) based on tag-recapture data from the iSimangaliso Wetland Park, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: BQ Mann --- Oceanographic Research Institute, South Africa B Lee --- Fisheries Department, Falkland Islands Government, Falkland Islands PD Cowley --- South African Institute for Aquatic Biodiversity, South AfricaThe growth rate of speckled snapper Lutjanus rivulatus was investigated using data from a long-term tag-recapture study conducted in the St Lucia Marine Reserve within the iSimangaliso Wetland Park, a World Heritage Site in northern KwaZulu-Natal, South Africa. A total... -
Retention of plastic-tipped dart tags in African tigerfish Hydrocynus vittatus
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: FJ Jacobs --- Ministry of Fisheries and Marine Resources, Namibia OLF Weyl --- DST/NRF Research Chair in Inland Fisheries and Freshwater Ecology, South Africa NS Libala --- Ministry of Fisheries and Marine Resources, Namibia GC O’Brien --- School of Life Sciences, South Africa CT Downs --- School of Life Sciences, South AfricaEstimates of tag retention and tagging-related mortality are essential for mark-recapture experiments. Mortality and tag loss were estimated from 15 tigerfish Hydrocynus vittatus marked using Hallmark model PDL plastic-tipped dart tags released into a 1 730 m2 pond at Kamutjonga... -
Movement patterns of an endangered fishery species, Lithognathus lithognathus (Sparidae), and the role of no-take marine protected areas as a management tool
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: RH Bennett --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa PD Cowley --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa A-R Childs --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa CG Attwood --- Department of Biological Sciences, South Africa L Swart --- Branch: Oceans and Coasts, Department of Environmental Affairs, South Africa TF Næsje --- South African Institute for Aquatic Biodiversity (SAIAB), South AfricaUnderstanding movement behaviour is essential for effective management of fishery species. Dart tags were used to study coastal movement patterns of white steenbras Lithognathus lithognathus, an overexploited seabream (Sparidae) in South Africa. In total, 6 962 fish (190–1 080 mm... -
Movement patterns and growth rate of the whitespotted wedgefish Rhynchobatus djiddensis in southern Africa based on tag-recapture data
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: GL Jordaan --- , South Africa BQ Mann --- , South Africa R Daly --- , South Africa SW Dunlop --- , South Africa PD Cowley --- , South AfricaInformation on the movement ecology of endangered species is critical for the implementation of effective conservation measures. This study made use of a long-term dart tagging dataset to reveal the movement patterns and growth rates of two size classes of... -
Bull shark Carcharhinus leucas recruitment into the St Lucia Estuary, South Africa, after prolonged mouth closure, and the first observation of a neonate bull shark preyed on by a Nile crocodile Crocodylus niloticus
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: R Daly --- , South Africa P Le Noury --- , United Kingdom TN Hempson --- , Mozambique M Ziembicki --- , Mozambique JM Olbers --- , South Africa GM Brokensha --- , South Africa BQ Mann --- , South AfricaEstuaries provide critical nursery habitat for juvenile bull sharks Carcharhinus leucas, as they have the ability to withstand a wide range of salinities. St Lucia is the largest estuarine lake in Africa and was once a key nursery for bull... -
Movement patterns and catch trends of the diamond ray Gymnura natalensis (Dasyatidae) in South African waters
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: R Daly --- , South Africa GL Jordaan --- , South Africa D Parker --- , South Africa G Cliff --- , South Africa N Nkabi --- , South Africa R Kyle --- , South Africa ST Fennessy --- , South Africa BQ Mann --- , South AfricaThe diamond ray Gymnura natalensis is endemic to southern Africa where its preference for shallow coastal habitats makes it vulnerable to recreational shore-based angling. Although it makes up approximately 1% of the shore-based tag numbers, little is known about its... -
Validation of growth zone formation in Oreochromis mossambicus otoliths collected from an irrigation pond in the Sundays River Valley, Eastern Cape, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: L Mofu --- Rhodes University, South Africa T Dalu --- University of Mpumalanga, South Africa RJ Wasserman --- South African Institute for Aquatic Biodiversity, South Africa DJ Woodford --- University of the Witwatersrand, South Africa OLF Weyl --- South African Institute for Aquatic Biodiversity (SAIAB), South AfricaIn fisheries science, life-history trait information is widely used to estimate fish population recruitment, growth, and mortality. The aging and growth of Oreochromis mossambicus from the Sundays River Valley irrigation pond in the Eastern Cape province of South Africa were... -
Movement patterns and underestimation of the maximum age of a Vulnerable endemic guitarfish species inferred from mark-recapture studies
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: TS Murray --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa C Elston --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa RH Bennett --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa A-R Childs --- Rhodes University, South Africa PD Cowley --- South African Institute for Aquatic Biodiversity (SAIAB), South AfricaData collected from mark-recapture programmes have proven invaluable in assessing the movements and growth of numerous fishery species along the South African coastline. This short note reports on tag and recapture information on the Vulnerable endemic lesser guitarfish Acroteriobatus annulatus... -
Acoustic telemetry reveals the drivers behind estuary–sea connectivity of an important estuarine-dependent fishery species, Pomadasys commersonnii, in the Breede Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: BA Ziko --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa TS Murray --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa TF Næsje --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa JD Filmalter --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa PD Cowley --- South African Institute for Aquatic Biodiversity (SAIAB), South AfricaThe spotted grunter Pomadasys commersonnii is an important estuarine-dependent fishery species known to spawn along the east coast (KwaZulu-Natal Province) of South Africa. However, recent evidence suggests that this species also spawns along the southwest coast in the Western Cape... -
Network analysis of the endemic spotted gully shark Triakis megalopterus reveals spatial vulnerability to exploitation in the Western Cape, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: E Cottrant --- , South Africa NJ Drobniewska --- , South Africa TL Johnson --- , South Africa LG Underhill --- University of Cape Town, South Africa TS Murray --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa N Hammerschlag --- University of Miami, United States PS Albano --- University of Miami, United States C Elston --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa ME McCord --- , South Africa PD Cowley --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa C Fallows --- , South Africa TG Paulet --- , South AfricaThe spotted gully shark Triakis megalopterus (Triakidae) is a mesopredatory species endemic to southern Africa. It is currently listed as Least Concern on the IUCN Red List in accordance with an estimated increase in population size, general release by recreational... -
Biology and ecology of the African blackspot shark Carcharhinus humani on the east coast of South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: G Cliff --- KwaZulu-Natal Sharks Board, South Africa NG Booyens --- School of Life Sciences, University of KwaZulu-Natal, South Africa R Daly --- Oceanographic Research Institute (ORI), South Africa GL Jordaan --- Oceanographic Research Institute (ORI), South Africa N Nkabi --- KwaZulu-Natal Sharks Board, South Africa D Parker --- Commonwealth Scientific and Industrial Research Organization, Australia BQ Mann --- Oceanographic Research Institute (ORI), South AfricaThe African blackspot shark Carcharhinus humani (until now commonly known as Human’s whaler shark) is a small-sized requiem shark (family Carcharhinidae) found in tropical coastal waters of the western Indian Ocean as far south as Port St Johns on the... -
Residency, site affinity and coastal movements of the southern African endemic spotted gully shark Triakis megalopterus
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: E Cottrant --- South African Shark Conservancy, South Africa JH Morrison --- South African Shark Conservancy, South Africa C Elston --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa TS Murray --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa NJ Drobniewska --- South African Shark Conservancy, South Africa LG Underhill --- Department of Biological Sciences, University of Cape Town, South Africa N Hammerschlag --- Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, United States PS Albano --- Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, United States ME McCord --- South African Shark Conservancy, South Africa PD Cowley --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa C Fallows --- Apex Shark Expeditions, South Africa TG Paulet --- South African Shark Conservancy, South AfricaRising global concern regarding the conservation and management of shark species makes it essential to identify key ecological species to guide conservation efforts, especially species with more restricted distributions such as endemic species. The southern African endemic spotted gully shark...