Alison A Kock

Alison A Kock
South African National Parks · Cape Research Centre, Tokai

PhD

About

55
Publications
34,990
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1,011
Citations
Citations since 2017
25 Research Items
754 Citations
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2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150

Publications

Publications (55)
Article
Full-text available
Human activities in the oceans increase the extinction risk of marine megafauna. Interventions require an understanding of movement patterns and the spatiotemporal overlap with threats. We analysed the movement patterns of 33 white sharks ( Carcharodon carcharias ) satellite-tagged in South Africa between 2012 and 2014 to investigate the influence...
Article
Full-text available
Risk-induced fear effects exerted by top predators are pervasive in terrestrial and marine systems, with lasting impacts on ecosystem structure and function. The loss of top predators can disrupt ecosystems and trigger trophic cascades, but the introduction of novel apex predators into ecosystems is not well understood. We documented the emigration...
Article
Full-text available
106,107 ✉ replying to A. V. Harry & J. M. Braccini Nature https://doi.org/10.1038/s41586-021-03463-w (2021) Our global analysis 1 estimated the overlap and fishing exposure risk (FEI) using the space use of satellite-tracked sharks and longline fishing effort monitored by the automatic identification system (AIS). In the accompanying Comment, Harry...
Article
This article is a response to Murua et al.'s Matters Arising article in Nature, "Shark mortality cannot be assessed by fishery overlap alone," which arose from arising from N. Queiroz et al. Nature https://doi.org/10.1038/s41586-019-1444-4 (2019).
Article
Wildlife tourism uses various stimuli to attract species and facilitate close encounters. Such activities are often referred to as provisioning, however the term is used interchangeably, and sometimes erroneously, with attracting, feeding, luring, and chumming, all of which lack consistent definitions. Here, we review the current use of provisionin...
Article
Top predators are important components of healthy ecosystems but are at risk of overexploitation due to insufficient data on life-history characteristics and population dynamics to guide management. We investigated the movements and growth rates of the broadnose sevengill shark Notorynchus cepedianus in southern Africa, using data from the Oceanogr...
Article
Full-text available
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 2...
Article
Full-text available
Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of...
Article
Full-text available
Over the past three decades, marine resource management has shifted conceptually from top-down sectoral approaches towards the more systems-oriented multi-stakeholder frameworks of integrated coastal management and ecosystem-based conservation. However, the successful implementation of such frameworks is commonly hindered by a lack of cross-discipl...
Article
Full-text available
In comparison to other behaviours, large predators expend relatively large amounts of energy foraging for prey, based on expected high return. Documenting how they manage costs and benefits of feeding is difficult, particularly for marine predators. In July and August of 2004 and 2005, we combined animal-borne video, accelerometry and depth sensors...
Article
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Apex predators play an important role in structuring food webs and are thus key components of healthy, stable ecosystems. While the loss of apex predators has been shown to disrupt ecosystems and trigger trophic cascades, the introduction of novel apex predators to functionally intact systems is less well understood. False Bay, South Africa, is an...
Article
Full-text available
White sharks, Carcharodon carcharias, are often described as elusive, with little information available due to the logistical difficulties of studying large marine predators that make long-distance migrations across ocean basins. Increased understanding of aggregation patterns, combined with recent advances in technology have, however, facilitated...
Article
Full-text available
The fast swimming and associated breaching behaviour of endothermic mackerel sharks is well suited to the capture of agile prey. In contrast, the observed but rarely documented breaching capability of basking sharks is incongruous to their famously languid lifestyle as filter-feeding planktivores. Indeed, by analysing video footage and an animal-in...
Article
Full-text available
Background Understanding white shark (Carcharodon carcharias) habitat use in coastal areas adjacent to large cities, is an important step when formulating potential solutions to the conservation conflict that exists between humans and large predatory sharks. In this study, we present the findings of a 2.5-year study of white shark occurrence and mo...
Article
Full-text available
A long-term sightings and photographic identification (photo-ID) database documented the inter-annual and monthly trends in white shark (Carcharodon carcharias) sightings, sex ratios and life-history stages at Seal Island, False Bay, South Africa, over the period 2004–2012. A total of 1105 sightings were recorded during 171 scientific surveys incor...
Technical Report
Full-text available
9. THE STATE OF INDIGENOUS SPECIES van der Bank MG, Adams R, Raimondo DC, Sink KJ, van der Colff D, Makhado A, Kock A, Porter S, Seakamela M, Louw S, Mann BQ, Bürgener M. 2019. Chapter 9: Indigenous Species. In: Sink KJ, van der Bank MG, Majiedt PA, Harris LR, Atkinson LJ, Kirkman SP, Karenyi N (eds). 2019. South African National Biodiversity Asses...
Article
Full-text available
White sharks (Carcharodon carcharias) are apex predators that play an important role in the structure and stability of marine ecosystems. Despite their ecological importance and protected status, white sharks are still subject to lethal control to reduce the risk of shark bites for recreational water users. The Shark Spotters program, pioneered in...
Article
Full-text available
Andreotti et al. (2016; Mar Ecol Prog Ser 552:241-253) estimate an abundance (N) of 438 white sharks Carcharodon carcharias and a contemporary effective population size (CNe) of 333 individuals along the South African coast. N was estimated by using a mark-recapture analysis of photographic identification records from a single aggregation site (Gan...
Article
Full-text available
Foraging and predation risk are often separated at rookeries of marine central place foragers, thus offering an opportunity to gain insight into how predator-avoidance shapes the behavior of prey. Here we compare the behavior of Cape fur seals (Arctocephalus pusillus pusillus) at two island rookeries with and without white shark (Carcharodon carcha...
Article
Full-text available
The marked differences in predation risk posed by white sharks (Carcarodon carcarias) at island rookeries of Cape fur seals (Arctocephalus pusillus pusillus) offer a quasi-experimental design within a natural system for exploring how prey adjust their behavior in response to temporal variation in predation risk. Here we compare movement of juvenile...
Article
Full-text available
Direct observations of sharks attacking mysticetes are rare. The present study provides the first direct observation of dusky sharks (Carcharhinus obscurus) attacking a humpback whale (Megaptera novaeangliae) calf. The event was witnessed on 16 July 2014 within the Pondoland Marine Protected Area, South Africa, during the annual sardine run. The ev...
Article
Full-text available
Shark attacks on humans are high profile events which can significantly influence policies related to the coastal zone. A shark warning system in South Africa, Shark Spotters, recorded 378 white shark (Carcharodon carcharias) sightings at two popular beaches, Fish Hoek and Muizenberg, during 3690 six-hour long spotting shifts, during the months Sep...
Article
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Elasmobranchs can detect minute electromagnetic fields, <1 nVcm(-1), using their ampullae of Lorenzini. Behavioural responses to electric fields have been investigated in various species, sometimes with the aim to develop shark deterrents to improve human safety. The present study tested the effects of the Shark Shield Freedom7™ electric deterrent...
Data
Example of interaction during which a shark approached within 0.5 m of an activated electric deterrent. (AVI)
Data
Example of interaction categorised as a breach. (MPG)
Data
Example of interaction categorised as an underwater interaction. (AVI)
Data
Example of interaction categorised as an investigation. (MPG)
Data
Example of a white shark taking the bait preceded by one approach and one interaction. (AVI)
Data
Example of a white shark taking the bait preceded by one approach and six interactions. (AVI)
Data
Example of interaction categorised as a surface interaction. (AVI)
Data
Example of interaction with a change of direction (proxy for a reaction to the electric deterrent). (WMV)
Data
Example of interaction categorised as a breach. (AVI)
Data
Example of interaction categorised as an aborted breach. (MPG)
Article
Full-text available
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...
Data
Results from the Generalized Linear Mixed Effects Model (GLMM) (with year) showing the likelihood of white sharks being at the Island versus Inshore. (DOCX)
Technical Report
Full-text available
http://pir.sa.gov.au/__data/assets/pdf_file/0017/232235/Risk_Assessment_of_the_Shark_Shield_Report_-_FINAL_19_06_2012.pdf
Article
Full-text available
We present both an empirical study and a behavioural game model exploring a predator–prey game between white sharks, Carcharodon carcharias, and Cape fur seals, Arctocephalus pusillus pusillus, around a small island colony in South Africa. Behavioural tactics used by adult seals appear to account for the variance in risk from sharks, while shark ta...
Technical Report
Full-text available
Print versions of presentations given by practitioners of animal-borne imaging research at the ABI Symposium held at National Geographic in 2007.
Article
Full-text available
Ecotourism operations which provide food to large predators have the potential to negatively affect their target species, by conditioning them to associate humans with food, or by generally altering their behavioural patterns, This latter effect could have potentially detrimental consequences for the ecosystem inhabited by the predator, because any...
Chapter
Full-text available
AUGUST 2006 White shark conservation and recreational safety in the inshore waters of Cape Town, South Africa P r o c e e d i n g s A u g u s t 2 0 0 6 Foreword The contents of these proceedings are the result of over a year's foresight and planning by the City of Cape Town, the Department of Environmental Affairs and Tourism (DEAT) and the World W...

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