34 research outputs found
Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)
No full textInternational audienceShark-based ecotourism has been recently expanding around the world. Provisioning sharks, however, is notwithout risk and accidental bites on humans are regularly reported. Such events may jeopardise the sharkecotourism industry and local economies. Through a case study from French Polynesia, I investigated whetherchanges in feeding practices of lemon sharks between the early 1990s and 2013 are related to recent accidentalbites of divers. Hand-feeding, ‘smelling’ and surface feeding facilitated the development of agonistic behaviourin sharks, which resulted in accidental bites. The level of interaction between sharks and humans appears to bethe most important driver for analysing bite-risk. This paper presents the very first framework for risk-analysisand will allow managers to better manage the risk associated with current practices in shark-feeding around theworld. The paper also provides technical guidelines for the design of adequate legal frameworks that will supportany sustainable shark feeding operation
Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)
No full textInternational audienceShark-based ecotourism has been recently expanding around the world. Provisioning sharks, however, is notwithout risk and accidental bites on humans are regularly reported. Such events may jeopardise the sharkecotourism industry and local economies. Through a case study from French Polynesia, I investigated whetherchanges in feeding practices of lemon sharks between the early 1990s and 2013 are related to recent accidentalbites of divers. Hand-feeding, ‘smelling’ and surface feeding facilitated the development of agonistic behaviourin sharks, which resulted in accidental bites. The level of interaction between sharks and humans appears to bethe most important driver for analysing bite-risk. This paper presents the very first framework for risk-analysisand will allow managers to better manage the risk associated with current practices in shark-feeding around theworld. The paper also provides technical guidelines for the design of adequate legal frameworks that will supportany sustainable shark feeding operation
Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)
No full textInternational audienceShark-based ecotourism has been recently expanding around the world. Provisioning sharks, however, is notwithout risk and accidental bites on humans are regularly reported. Such events may jeopardise the sharkecotourism industry and local economies. Through a case study from French Polynesia, I investigated whetherchanges in feeding practices of lemon sharks between the early 1990s and 2013 are related to recent accidentalbites of divers. Hand-feeding, ‘smelling’ and surface feeding facilitated the development of agonistic behaviourin sharks, which resulted in accidental bites. The level of interaction between sharks and humans appears to bethe most important driver for analysing bite-risk. This paper presents the very first framework for risk-analysisand will allow managers to better manage the risk associated with current practices in shark-feeding around theworld. The paper also provides technical guidelines for the design of adequate legal frameworks that will supportany sustainable shark feeding operation
Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)
No full textInternational audienceShark-based ecotourism has been recently expanding around the world. Provisioning sharks, however, is notwithout risk and accidental bites on humans are regularly reported. Such events may jeopardise the sharkecotourism industry and local economies. Through a case study from French Polynesia, I investigated whetherchanges in feeding practices of lemon sharks between the early 1990s and 2013 are related to recent accidentalbites of divers. Hand-feeding, ‘smelling’ and surface feeding facilitated the development of agonistic behaviourin sharks, which resulted in accidental bites. The level of interaction between sharks and humans appears to bethe most important driver for analysing bite-risk. This paper presents the very first framework for risk-analysisand will allow managers to better manage the risk associated with current practices in shark-feeding around theworld. The paper also provides technical guidelines for the design of adequate legal frameworks that will supportany sustainable shark feeding operation
Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)
No full textInternational audienceShark-based ecotourism has been recently expanding around the world. Provisioning sharks, however, is notwithout risk and accidental bites on humans are regularly reported. Such events may jeopardise the sharkecotourism industry and local economies. Through a case study from French Polynesia, I investigated whetherchanges in feeding practices of lemon sharks between the early 1990s and 2013 are related to recent accidentalbites of divers. Hand-feeding, ‘smelling’ and surface feeding facilitated the development of agonistic behaviourin sharks, which resulted in accidental bites. The level of interaction between sharks and humans appears to bethe most important driver for analysing bite-risk. This paper presents the very first framework for risk-analysisand will allow managers to better manage the risk associated with current practices in shark-feeding around theworld. The paper also provides technical guidelines for the design of adequate legal frameworks that will supportany sustainable shark feeding operation
Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)
No full textIndividual shark profiling: An innovative and environmentally
Get PDFMost shark-induced human fatalities are followed by widespread and unselective
culling campaigns that have limited effectiveness and may have high ecological costs
for threatened species. The blanket culling strategy implicitly assumes that incident
risk is directly correlated with shark density, an assumption that has yet to be demonstrated.
We present the alternative hypothesis that incidents are more likely to be
caused by behavioral variability among individual sharks than due to shark density.
Throughout their ontogenetic development, large species of sharks opportunistically
establish a diet that is rarely, if ever, inclusive of humans as a food source. We propose
that, some animals with specific behaviors (including boldness) may potentially
pose a higher risk than conspecifics. Under this scenario, the risk of a shark attack in
a given area would relate to the presence of a limited number of high-risk individuals
rather than shark density.
In terms of management of human fatalities, such a hypothesis would favor abandoning
general culling campaigns and replacing them with approaches that profile
and selectively remove the potential problem individuals, as is done in the terrestrial
realm when managing predators that attack humans or livestock.publishedVersio
Marine Science and Engineering A Time-Extended (24 h) Baited Remote Underwater Video (BRUV) for Monitoring Pelagic and Nocturnal Marine Species
No full textInternational audienceBaited remote underwater video systems (BRUVs) are efficient devices for remotely characterising the assemblage and relative density of fishes and other marine organisms. However, technological constraints (e.g., battery life and limited storage memory) typically limit deployment times to <2 h making it very difficult to capture the presence of marine species, including rare and elusive ones. We developed an extended duration (24 h) BRUV to enable fisheries-independent surveying of a pelagic shark population in the western Mediterranean. Video data revealed seven visits (three nocturnal, four diurnal) by blue sharks (Prionace glauca) over a period of 1355 h. In the future, this cost-effective device could be fitted with a wireless video transmitter to provide real-time observations of marine animals for scientific or ecotourism purposes
The ‘Mistaken Identity Hypothesis’ for shark bites on humans is an anthropomorphic fallacy
No full textInternational audienceThe Mistaken Identity Hypothesis (MIH) interprets shark bites on surfers, swimmers and snorkelers as 'mistakes' stemming primarily from similarities in the visual appearance of ocean users and the sharks typical prey. MIH is now widely accepted as fact by the general public and some sections of the scientific community despite remaining unproven. This hypothesis assumes that 'mistaken' shark bites on humans result primarily from confusing visual cues and ignores the important role of other senses (e.g. hearing) in discriminating potential prey. A far simpler 'natural exploration' hypothesis can reasonably explain not only shark bites that have been characterized as 'mistaken identity' events but also those that cannot be reasonably explained by MIH (e.g. shark bites that occur in very clear water). Simply stated, sharks don't make 'mistakes' but instead continually explore their environments and routinely investigate novel objects as potential prey by biting them
The role of social transmission in the use of a new behaviour by killer whales in response to fisheries
No full textHuman exploitation profoundly impacts ecosystems but can also provide novel feeding opportunities to which animals may respond by learning new foraging behaviours. Among these, feeding on fisheries catch or byproduct, a behaviour termed ‘depredation’, has been observed in many large marine predator species globally. However, for social species, how social transmission influences both the acquisition of and the level of engagement in such behaviour by individuals within populations remains poorly understood. In this study, we analysed 18 years (2005–2022) of photo-identification data, with a combination of both social and diffusion models, to assess the role of social transmission in the acquisition of depredation by social units of the killer whale population of the Crozet Islands, as well as the extent to which social units engaged in this behaviour once acquired. We found that an increasing number of social units acquired depredation behaviour over time and that they did so through learning from other units and independent learning. We also demonstrate that during the years following this acquisition, their level of engagement in depredation was influenced by social preferences, with closely associated units showing similar levels of depredation and certain units acting as structural key nodes facilitating the transmission of depredation within the network. However, past the year when the entire population had acquired depredation, we found that factors other than social transmission came into play to explain heterogeneity in depredation levels observed across social units. Together, these findings highlight the role of social dynamics in shaping species' response to human-induced changes in their environment and in leading to intrapopulation behavioural heterogeneity that can have major implications for the long-term conservation of top marine predator populations
