Residency, Habitat Use and Sexual Segregation of White Sharks, Carcharodon carcharias in False Bay, South Africa

AbstractThe seasonal occurrence and temporal sexual segregation of great white sharks Carcharodon carcharias have been widely documented in various temperate and sub-tropical waters across the globe. Yet, there is limited understanding of the relationship between the life stages and habitat use of C. carcharias, particularly in the Southern Cape. In this study, we investigated the population dynamics of C. carcharias in Mossel Bay, South Africa, between 2009 and 2013, using skipper logbooks and citizen research data obtained by a cage-diving vessel. A total of 3064 sharks, ranging in life history stages from young-of-the-year to subadult, were sighted during 573 trips. Juveniles dominated the sightings throughout the study, and there was marked sexual segregation, with females dominating the total sightings of sharks. C. carcharias were most abundant during the cooler, winter season, with females differing in abundance seasonally and males maintaining a low abundance throughout the year but peaking in the winter. In addition, sea surface temperature was the best indicator of C. carcharias presence. Abundance was greatest when vertical water visibility exceeded 3 m, with cloud cover influencing overall abundance negatively. Likely reasoning for the aggregation of C. carcharias in Mossel Bay includes the favourable conditions and abundance of food. Juvenile sharks may also utilise this area as a training ground to learn from larger conspecifics. This research demonstrates that information on population size and structure of C. carcharias can be obtained effectively through a compilation of logbook and citizen science data to assess and identify potential critical habitats in the quest to develop appropriate management strategies. This research also shows value in commercial cage-diving operations deriving international data sets needed to assess global populations of C. carcharias.

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Habitat Use by Nile Crocodiles in Ndumo Game Reserve, South Africa: A Naturally Patchy Environment

Herpetologica ◽

10.1655/herpetologica-d-13-00088 ◽

2014 ◽

Vol 70 (4) ◽

pp. 426-438 ◽

Cited By ~ 14

Author(s):

Peter M. Calverley ◽

Colleen T. Downs

Keyword(s):

South Africa ◽

Habitat Use ◽

Patchy Environment ◽

Game Reserve

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Spatial ecology and habitat use of giraffe ( Giraffa camelopardalis ) in South Africa

Basic and Applied Ecology ◽

10.1016/j.baae.2017.04.003 ◽

2017 ◽

Vol 21 ◽

pp. 55-65 ◽

Cited By ~ 5

Author(s):

Francois Deacon ◽

Nico Smit

Keyword(s):

South Africa ◽

Habitat Use ◽

Spatial Ecology ◽

Giraffa Camelopardalis

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Integrating field data

Remote Sensing for Ecology and Conservation ◽

10.1093/oso/9780199219940.003.0021 ◽

2010 ◽

Author(s):

Ned Horning ◽

Julie A. Robinson ◽

Eleanor J. Sterling ◽

Woody Turner ◽

Sacha Spector

Keyword(s):

South Africa ◽

Habitat Use ◽

Vegetation Type ◽

Remotely Sensed ◽

Battery Life ◽

Clear Understanding ◽

Remotely Sensed Data ◽

Human Settlements ◽

Ecological Gradient ◽

Landsat 7

While the savannah elephant (Loxodonta africana) is listed by the International Union for Conservation of Nature (IUCN) as “vulnerable” because of declining abundance in some regions of Africa (Blanc 2008), populations in some protected areas of South Africa are growing rapidly (van Aarde and Jackson 2007). These populations can cause extensive modification of vegetation structure when their density increases (Owen-Smith 1996; Whyte et al. 2003; Guldemond and van Aarde 2007). Management methods such as culling, translocation, and birth control have not reduced density in some cases (van Aarde et al. 1999; Pimm and van Aarde 2001). Providing more space for elephants is one alternative management strategy, yet fundamental to this strategy is a clear understanding of habitat and landscape use by elephants. Harris et al. (2008) combined remotely sensed data with Global Positioning System (GPS) and traditional ethological observations to assess elephant habitat use across three areas that span the ecological gradient of historical elephant distribution. They explored influences on habitat use across arid savannahs (Etosha National Park in Namibia) and woodlands (Tembe Elephant Park in South Africa and Maputo Elephant Reserve in Mozambique). The researchers focused on three main variables—distance to human settlements, distance to water, and vegetation type. The authors used Landsat 7 ETMþ imagery to create vegetation maps for each location, employing supervised classification and maximum likelihood estimation. Across all sites, they recorded the coordinates of patches with different vegetation and of vegetation transitions to develop signatures for the maps. Elephants do not use all vegetation types, and it can be expedient to focus on presence rather than both presence and absence. Accordingly, the researchers used GPS to record the locations of elephants with the aim of identifying important land cover types for vegetation mapping. The authors mapped water locations in the wet and dry seasons using remotely sensed data and mapped human settlements using GPS, aerial surveys, and regional maps. They tracked elephants with radiotelemetry collars that communicated with the ARGOS satellite system, sending location data for most of the elephants over 24 h, and then remaining quiescent for the next 48 h to extend battery life.

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Shark–Cetacean trophic interaction, Duinefontein, Koeberg, (5 Ma), South Africa

South African Journal of Science ◽

10.17159/sajs.2015/20140453 ◽

2015 ◽

Vol Volume 111 (Number 11/12) ◽

Cited By ~ 3

Author(s):

Romala Govender ◽

Keyword(s):

South Africa ◽

Cause Of Death ◽

West Coast ◽

Trophic Interaction ◽

The West ◽

Carcharodon Carcharias ◽

Inverted Position ◽

Bite Marks ◽

Shark Teeth ◽

Long Time

Abstract This study forms part of a larger project to reconstruct the Mio-Pliocene marine palaeoenvironment along South Africa’s west coast. It documents the shark–cetacean trophic interaction during the Zanclean (5 Ma) at Duinefontein (Koeberg). The damage described on the fragmentary cetacean bones was compared with similar damage observed on fossils from Langebaanweg, a Mio-Pliocene site on the west coast of South Africa, and data present in the literature. This comparison showed that the damage was the result of shark bites. The state of preservation makes it difficult to determine if the shark bite marks were the cause of death or as a result of scavenging. The presence of the bite marks on the bone would, however, indicate some degree of skeletonisation. Bite marks on some cranial fragments would suggest that the cetacean’s body was in an inverted position typical of a floating carcass. The preservation of the material suggests that the bones were exposed to wave action resulting in their fragmentation as well as abrasion, polishing and rolling. It also suggests that the cetacean skeletons were exposed for a long time prior to burial. The morphology of the bites suggests that the damage was inflicted by sharks with serrated and unserrated teeth. Shark teeth collected from the deposit include megalodon (Carcharodon megalodon), white (Carcharodon carcharias) as well as mako (Isurus sp. and Cosmopolitodus hastalis) sharks, making these sharks the most likely predators/scavengers.

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Coastal swimming patterns of white sharks (Carcharodon carcharias) at Mossel Bay, South Africa

Environmental Biology of Fishes ◽

10.1007/s10641-009-9477-4 ◽

2009 ◽

Vol 85 (3) ◽

pp. 189-200 ◽

Cited By ~ 28

Author(s):

Ryan Johnson ◽

Marthán N. Bester ◽

Sheldon F. J. Dudley ◽

W. Herman Oosthuizen ◽

Michael Meÿer ◽

...

Keyword(s):

South Africa ◽

Carcharodon Carcharias

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Forage, Habitat use, and Sexual Segregation by a Tropical Deer (Cervus Eldi Thamin) in a Dipterocarp Forest

Journal of Mammalogy ◽

10.1093/jmammal/82.3.848 ◽

2001 ◽

Vol 82 (3) ◽

pp. 848-857 ◽

Cited By ~ 5

Author(s):

W. J. McShea ◽

M. Aung ◽

D. Poszig ◽

C. Wemmer ◽

S. Monfort

Keyword(s):

Habitat Use ◽

Sexual Segregation ◽

Dipterocarp Forest

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Antibiotic sensitivity of bacteria isolated from the oral cavities of live white sharks (Carcharodon carcharias) in South African waters

South African Journal of Science ◽

10.17159/sajs.2019/5972 ◽

2019 ◽

Vol 115 (11/12) ◽

Author(s):

Enrico Gennari ◽

Alison A. Kock ◽

Malcolm J. Smale ◽

Alison Towner ◽

Nasreen Khan ◽

...

Keyword(s):

South Africa ◽

Antibiotic Resistance ◽

South African ◽

Antibiotic Sensitivity ◽

White Shark ◽

Shark Species ◽

Apex Predators ◽

Carcharodon Carcharias ◽

Bacterial Microbiota ◽

Carbapenem Antibiotic

The white shark (Carcharodon carcharias) is responsible for 49% of shark-related injuries in South Africa, yet no information currently exists on the composition or antibiotic resistance of bacteria hosted by these apex predators in South African waters. This study aimed to address this gap by sampling the bacteria present in the oral cavities of 28 live C. carcharias along South Africa’s southern coastline. The antibiotic resistance of the range of microbiota was also assessed using antibiotic disc diffusion tests. A total of 51 strains from at least 20 species of bacteria were isolated from the oral cavities of C. carcharias. Of these strains, the most common bacteria present were Serratia spp., Proteus vulgaris and Vibrio alginolyticus. The overall antibiotic resistance was relatively higher in this study than that reported for bacterial microbiota sampled from other shark species. Results indicate that the combination therapy of imipenem (carbapenem antibiotic) and vancomycin (glycopeptide antibiotic) might be the most parsimonious option to effectively treat infections resulting from white shark bites, particularly in South Africa. It is hoped that, in addition to assisting medical professionals to treat shark bite victims, these findings enhance the understanding of the microbial communities present in large coastal predators and their surrounding environments.

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