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Managing bite risk for divers in the context of shark feeding ecotourism: A case study from French Polynesia (Eastern Pacific)

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... The motivations for shark bites may include foraging (6,15) but many other motivations exist such as exploration, defense, territoriality, competition (15)(16)(17)(18), or confusion (19). From a forensic point of view, foraging aggressions would involve a loss of ingested tissues whereas other motivations would result in more superficial wounds (7). ...
... In addition, the sicklefin lemon shark is a piscivore and, as such, it would be highly unusual that this species would have intentionally fed on a human prey. Defense (by fear or following a human aggression, [15]), competition (for a food source, [16,17]), and confusion (19) may also lead to superficial wounds but rather involve spearfishes and scuba divers in underwater interactions with sharks carrying out provoked bites that hardly concern the surfing activity. ...
... The sicklefin lemon shark is very common in French Polynesia and is one of the most common shark species involved in underwater shark-based ecotourism activities, mainly those located in the Society islands such as Tahiti, Moorea or Bora-Bora (19). This species is present in the Tuamotu archipelago, including Makemo atoll as indicated by local fishermen. ...
Article
Identifying the species and size of sharks responsible for biting humans is essential for developing strategies to prevent these incidents. Here, we use bite wound characteristics and genetic analysis of a tooth fragment extracted from the wounds to identify a sicklefin lemon shark Negaprion acutidens as the perpetrator of nonfatal bites on the legs of an adult male surfer at Makemo atoll (French Polynesia) in January 2018. The bite was superficial, and N. acutidens are fish predators not known to feed on large prey; hence, foraging is an unlikely explanation for this incident rather linked to territoriality. Lemon sharks are occasionally aggressive toward humans and are site attached with relatively small home ranges; hence, avoiding surfing in the area of a previous bite incident is recommended to decrease the risk of future injuries.
... However, other studies did not show any significant negative impacts on ecology and behavior of targeted elasmobranchs species including white sharks (Carcharodon carcharias) (Laroche et al., 2007), Caribbean reef sharks (Carcharhinus perezii) (Maljković & Côté, 2011), tiger sharks (Galeocerdo cuvier) (Hammerschlag et al., 2012), bull sharks (Carcharhinus leucas) (Abrantes et al., 2018;Brunnschweiler & Barnett, 2013), and juvenile lemon sharks (Negaprion brevirostris) (Heinrich et al., 2021). Thus, shark provisioning appears to have differential effects depending upon practices, with hand or surface feeding facilitating the development of agonistic behavior in sharks for instance (Clua, 2018), and species, with resident species potentially more affected than highly mobile species (Mourier et al., 2021). ...
... Indeed, fishing and habitat loss remain the main causes of elasmobranch declines, and addressing these threats should remain the priority of conservation efforts for these species (Dulvy et al., 2014;Healy et al., 2020). Furthermore, the use of codes of conduct standardizing ways to bait animals and to behave in the water during provisioning should help to minimize the potential impacts of this tourism activity on wildlife and on the safety of participants (Abrantes et al., 2018;Clua, 2018;Clua & Torrente, 2015;Gallagher et al., 2015;Healy et al., 2020;Newsome et al., 2004;Zimmerhackel et al., 2019) while increasing the ecological and economic benefits (Semeniuk et al., 2009;Zimmerhackel et al., 2018). Evidence in the wild, including from this study, reveals strong levels of conditioning in sharks and rays strengthens the need for these codes of conduct to be adopted, implemented, and enforced in every provisioning site around the world. ...
Article
The tourism activities linked to artificial provisioning of blacktip reef sharks (Carcharhinus melanopterus) and pink whiprays (Pateobatis fai) on a specific site in French Polynesia were suddenly and completely stopped due to a COVID-19 lockdown that lasted 6 weeks from March 20 until April 30, 2020. Using both drone footage and underwater counting, we were able to track the abundance of those two species before, during, and after reopening and thus investigate the impact of provisioning on wild shark populations. The absence of any stimulus during this long period resulted in almost total desertion of the site by the elasmobranchs. However, 1 day prior to reopening, some individuals of both species positively reacted to the single acoustic stimulus of an engine boat, showing the resilience of conditioning, and some elasmobranchs reacted to acoustic and olfactive stimuli linked to the provisioning practice from the first day after reopening. During the first 2 weeks after reopening, the abundance of both species remained at reduced levels comparable to those observed between 2008 and 2010 for sharks; i.e., around 9 animals in the presence of local tourists. Pre-lockdown abundance levels, reaching approximatively 15 individuals for sharks and 10 for rays, were considered restored 1 and 2 months after reopening for blacktip reef sharks and pink whiprays, respectively. These findings improve our capacity to better understand the potential effects of artificial provisioning tourism on the abundance of elasmobranchs by showing that conditioning is resilient for several weeks, suggesting that intermittent interruption of elasmobranchs feeding would not really help to decrease its impact on animal welfare.
... They are two of the very few bites about which it was possible to gather reliable data in order to conduct this analysis. Bites (whatever their severity) in the context of shark diving definitely happen regularly [11,18], but diving operators are very reluctant to communicate and report them, due to the risk of a strong negative impact on ecotourism activity and subsequent economic impacts [1]. ...
... We strongly believe that for the two documented bites, the visual stimulus was dominant and facilitated by uncovered skin, which can easily be confounded with any fish flesh, as no clear evidence of anything other than monochromatic vision has been shown for the Lemon shark [24]. In the context of the second accident, the movements of the arm and the hand on the strobe were probably a determining factor for stimulating the accidental bite, by incidentally simulating a hand-feeding stimulus, as described for a similar bite in February 2013 on a diver's hand in Bora-Bora [18]. ...
Article
Introduction: Shark-based ecotourism is significantly developping around the world, often without appropriate management of risk. This activity involves a risk of accidental bites on divers that can be quite severe or even fatal. Objectives: To determine if ecotourism companies’ liability can be engaged in the context of bites on scuba divers in presence of hand-feeding practices, supporting the legitimacy of financial compensation for the victims. Methods: We analyzed the development from the mid-eighties to 2010 of shark-based ecotourism through artificial provisioning practices in Moorea island (French Polynesia) and more specifically the features and motivation of two bites on divers by Sicklefin Lemon sharks. Results: The specific practice of hand-feeding can be considered as a facilitating factor for accidental bites on divers, potentially involving the diving operator’s responsability. Conclusions: Our findings should support the technical work of experts that might be called in such cases.
... Efficient portfolio is of the portfolio that they generate a level of certain benefits with the risk of the lowest, or certain risks to the level of the highest profit. (Clua, 2018;Fletcher, 2010;Tan, 2001) Own portfolio are defined as a collection of documents from someone, the group , institutions , organization , the company , and the like to document the development of a process in accomplish its intended purpose, but the term it differs from one parcel of two other sectors. (Borekci, Rofcanin, & Sahin, 2014;Rouibah, Lowry, & Hwang, 2016) For instance in the field of art , portfolios are defined as a collection of has the best from an artist who deliberately held for the purpose of the exhibition , while in educational world to the portfolio is a collection of the results of the work of a students as the results of the execution of a task on the performance of which determined teacher or by students with teachers. ...
... In these cases, different methods of supplying either bait or attractants may be employed, which mainly entail chumming, baiting, or feeding. Chumming consists of releasing fish fluids and tissues into the water to attract sharks over large areas, whereas baiting consists of using real or artificial bait to attract sharks passively or actively either visually or by smell [10,14,15]. ...
Article
Cabo Pulmo National Park was established in 1995 and has since seen a large increase in fish biomass. An unoccupied aerial vehicle (UAV) was used to survey shallow coastal habitat in which lemon sharks (Negaprion brevirostris), bull sharks (Carcharhinus leucas) and Pacific nurse sharks (Ginglymostoma unami) were recorded. Sharks were more common in the afternoon, potentially utilising warmer shallow areas to behaviourally thermoregulate. This study highlights UAV surveying to be a viable tool for species identification, a limitation of previous terrestrial surveys conducted in the area. This article is protected by copyright. All rights reserved.
... In these cases, different methods of supplying either bait or attractants may be employed, which mainly entail chumming, baiting, or feeding. Chumming consists of releasing fish fluids and tissues into the water to attract sharks over large areas, whereas baiting consists of using real or artificial bait to attract sharks passively or actively either visually or by smell [10,14,15]. ...
Article
The Guadalupe Island Biosphere Reserve is one of the main aggregation sites for the white shark Carcharodon carcharias and is considered to be the best place in the world for white shark cage diving. From 2014 to 2019, the number of cage diving vessels in Guadalupe Island grew from 6 to 10, with an estimated 2800 tourists participating in white shark cage diving during the 2019 season. In 2016, the National Commission of Protected Natural Areas of Mexico requested a carrying capacity in which current regulations, white shark behavior, and the management capacity of the reserve were considered. To characterize the movement patterns of the white shark, 12 individuals were acoustically tracked. Based on the critical habitat of the white shark determined by an analysis of kernel densities, three carrying capacity scenarios (i.e., critical, optimal, and expanded) were calculated in which 1, 6 or 12 vessels, respectively, could operate simultaneously. It is important to consider that as the number of simultaneously operating cage diving vessels increases, the probability of sighting a white shark decreases [> 0.9 (critical scenario), > 0.5 (optimal scenario), and > 0.1 expanded scenario]. The results of this study may act as a baseline for the management of other white shark tourism and aggregation sites in the world. However, future studies should also include other variables, such as the energy budget, due to the use of attractants in cage diving that may potentially affect individual behavior.
... Compared to the very few fatal bites, on a global basis there are hundreds of non-lethal shark bites on humans, most of them unreported, perpetrated by many shark species potentially driven by many different motivations including self-defense (Balbridge, 1988;Gruber, 1988), territoriality, hunger or competition (Johnson and Nelson, 1973;Gruber, 1988;Jublier and Clua, 2018) or misidentification of prey (Clua, 2018). However, these agonistic behaviours usually only cause non-fatal superficial wounds and do not trigger the initiation of unselective culling campaigns and are therefore not the priority focus of our discussion. ...
Article
Selective removal of problem individuals following shark bite incidents would be consistent with current management practices for terrestrial predators, and would be more effective and more environmentally responsible than current mass-culling programs. In parallel, and in addition to traditional forensics analysis, we recommend the routine collection of shark DNA from wounds or devices following shark bite incidents in order to genetically identify the individual responsible. This approach would require creating an extensive database of shark identities in high-risk areas against which to compare DNA forensically recovered from shark bite incidents. At a local and regional scale, we propose utilizing existing shark tagging programs and artificial shark aggregation sites to collect DNA, behavioural and morphological data for the database, and to facilitate removal of problem individuals. In several places around the world, selective removal of problem individuals would not be significantly more expensive and definitely less environmentally-destructive than traditional approaches and would also help reconcile people and sharks by underlining individuality in shark behaviour.
... Given the uncertainty of some industry impacts and likely underreporting of elasmobranch tourism incidents (e.g. bites, 'troublesome behaviour' [38]), the precautionary principal was applied [56]. Calculations are therefore likely to have a bias to overestimating risk but this was deemed appropriate, as doing so reduces the likelihood of assigning a lower risk rating that might actually be present for the given context. ...
Article
Elasmobranch tourism is a rapidly expanding global industry. While this industry can provide community and conservation benefits, it presents risks to target species, environments and humans when inappropriately managed. To ensure appropriate management is implemented, there is a need to identify the prevalence of elasmobranch tourism globally, the types of operations occurring and the controls used to mitigate risk. This study undertook a global literature review to develop an industry activity typology and establish the types of management controls present across elasmobranch tourism operations. In total, 151 unique species-activity-location conditions were identified, with four broad activity types categorised: diving, snorkelling, provisioning and cage diving. Spanning 42 countries and 49 different species, 32% of conditions identified lacked evidence of management. Further to this, many of the prevailing management controls in place (e.g. MPAs, shark sanctuaries, protected species status), were secondary in nature, having not been designed or implemented to manage elasmobranch tourism explicitly. Therefore, avoidable risks are likely widespread throughout the industry. Encouragingly, the application of activity specific management controls is likely to be effective at reducing risks across activity types. The theoretical case studies and management tools investigated herein provide operators and industry managers with guidance on how to reduce risk and safeguard industry benefits. With the elasmobranch tourism industry likely to continue expanding, it is important that appropriate management and regulatory frameworks are in place so that marine wildlife tourism can continue in a beneficial and sustainable manner.
... At the same time, special attention is also paid to minimizing the risks of tourists when watching sharks. It is proposed that regulatory guidelines be established to develop an adequate legal framework that will support any sustainable shark feeding operation [23]. The legal regulation of tourism in Antarctica is actively developing. ...
... The controversy for shark provisioning has been existed since the practice were introduced in 1980-1990s, most notably due to its animal welfare critics, fitness and bioenergetics factors, and shark watcher safety [7]. Despite its potential bite risks [8] during shark diving or watching, behavior shifting on a specific reefshark -e.g. Carcharhinus perezithat has been affected by prolonged provisioning were considered as 'no evidence" [9]. ...
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Ecotourism represents a highly popularised activity which has exhibited global growth in recent years. In the present paper, we examine the distribution, frequency, and economic value of shark-based ecotourism operations worldwide. A total of 376 shark ecotour operations across 83 locations and 8 geographic regions were identified. Here we describe the global and regional scope of the industry; determine the species utilised in shark ecotourism activities; and examine the recreational usage values of sharks. Further, we conducted a case study of a shark tourism operation based in South Africa by analysing 12 years of demographical and economical data, revealing increasing trends in the total number of customers served and cost per trip over the sampling period. We also compare consumptive and non-consumptive values of shark resources and discuss the potential research and conservation implications of the industry to sharks worldwide.
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Coral reefs in French Polynesia, just like many others throughout the world, have been subjected to several natural disturbances including 15 cyclones, seven major bleaching events, and several Acanthaster planci outbreaks since the 1980s. In order to document the effects of these perturbations on coral assemblages, we initiated a long-term monitoring program that extended over both local and regional scales. Coral cover was quantified at 20 sites situated on the outer reef slope of 13 islands. The results from the first decade (1992-2002) are analyzed and the adequacy of our approach is discussed in the context of identifying potential indicators of coral reef health. Among 13 islands in French Polynesia, only two were unaffected by natural disturbances. We found important local and regional variation in the impacts of coral bleaching and cyclones, and three major temporal trends were distinguished: 1) 10 sites where coral cover decreased in relation to the occurrence of major disturbances; 2) nine sites where coral cover increased, despite the occurrence of disturbances affecting seven of them; and 3) a site where no significant variation in coral cover was found. The responses to perturbations were different among coral genera: Acropora species were particularly susceptible to bleaching events, whereas physical damages induced by cyclones concerned mainly branching species of Acropora and Pocillopora. Thus, monitoring surveys could be improved by selecting different and complementary indicators (one on the variation in diversity, one estimating changes in the abundance/cover, and one estimating the potential for recovery), by integrating several spatial scales, and by including at least the most informative species. High frequency recordings of environmental parameters (e.g. sea surface temperature) may be also a complementary tools for identifying causal relationships between changes in coral reef community structure and the factors causing the changes.
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Little is known about the sensory abilities of elasmobranchs (sharks, skates and rays) compared with other fishes. Despite their role as apex predators in most marine and some freshwater habitats, interspecific variations in visual function are especially poorly studied. Of particular interest is whether they possess colour vision and, if so, the role(s) that colour may play in elasmobranch visual ecology. The recent discovery of three spectrally distinct cone types in three different species of ray suggests that at least some elasmobranchs have the potential for functional trichromatic colour vision. However, in order to confirm that these species possess colour vision, behavioural experiments are required. Here, we present evidence for the presence of colour vision in the giant shovelnose ray (Glaucostegus typus) through the use of a series of behavioural experiments based on visual discrimination tasks. Our results show that these rays are capable of discriminating coloured reward stimuli from other coloured (unrewarded) distracter stimuli of variable brightness with a success rate significantly different from chance. This study represents the first behavioural evidence for colour vision in any elasmobranch, using a paradigm that incorporates extensive controls for relative stimulus brightness. The ability to discriminate colours may have a strong selective advantage for animals living in an aquatic ecosystem, such as rays, as a means of filtering out surface-wave-induced flicker.
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Humans can dive with critically endangered grey nurse sharks (Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.
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Introduction: Shark-based ecotourism is significantly developping around the world, often without appropriate management of risk. This activity involves a risk of accidental bites on divers that can be quite severe or even fatal. Objectives: To determine if ecotourism companies’ liability can be engaged in the context of bites on scuba divers in presence of hand-feeding practices, supporting the legitimacy of financial compensation for the victims. Methods: We analyzed the development from the mid-eighties to 2010 of shark-based ecotourism through artificial provisioning practices in Moorea island (French Polynesia) and more specifically the features and motivation of two bites on divers by Sicklefin Lemon sharks. Results: The specific practice of hand-feeding can be considered as a facilitating factor for accidental bites on divers, potentially involving the diving operator’s responsability. Conclusions: Our findings should support the technical work of experts that might be called in such cases.
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We report several shark attacks and bites which occurred in French Polynesia. This kind of accident seems to be more common in this country than in other French Indo-Pacific islands. In most of the cases we recorded, injuries were not major, and no death occured. Sharks involved in these accidents were small or medium-sized fisheaters. Fish blood or flesh close to the victim while performing scuba diving with shark feeding or spearfishing appears to have worked as a stimulus on sharks, and according to our data should be considered as a major factor of such accidents.
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Lemon sharks 3 months old can be conditioned to press a target for food. They show a greater ability to accomplish this in our testing situation than do bull sharks of the same age. Young bull and lemon sharks respond more readily to this type of experiment than do the adults.
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Tiger Sharks, Galeocerdo cuvier, are large top-level predators usually solitary as adults. Observation of their scavenging activity on the carcass of a dead whale offered a rare opportunity for better understanding the pattern of intra-specific behaviour within the aggregations of these large predators. In January 2002, the stranding, subsequent death and consumption of a 17.4m total length (TL) blue whale, Balaenoptera musculus, was observed and filmed in Prony Bay, southern New Caledonia. After three weeks of confinement in the bay, the cetacean was killed by adult bullsharks Carcharhinus leucas. The first adult Tiger Shark was subsequently observed around the carcass after 36h. The fat slicks from the carcass attracted further Tiger Sharks which arrived after an additional 24h. The use of photo-identification on video footage collected during four observation sessions over an eight-day period identified 46 individual Tiger Sharks (primarily adult females between 3.3 and 4m TL) participating in the feeding aggregation. Only four animals were identified in two seperate observation sessions (over two consecutive days), suggesting a short-term residency pattern of several hours (<36h) around the carcass. As the arrival time of Tiger Sharks to the carcass differed, most arrivals of a new participant were followed by a frenzied period of intense intra-specific interaction. Different biting and agonistic behaviours were demonstrated by the Tiger Sharks on the carcass, including three new behaviours previously undescribed for this species. Size and level of aggressiveness appeared to be the determining factors of dominance amongst Tiger Sharks. These observations and analysis demonstrate that systematic study of feeding aggregations supported by photo-identification could contribute to knowledge of large shark ecology when coupled with capture-recapture, genetic fingerprinting and tagging techniques.
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Marine-based tourism offers opportunities for economic, educational and environmental benefits but is not without risks to people, animals and the environment. If the benefits of this sector are to be harnessed it will require an increasing focus upon law and policy governing the industry. This is particularly the case for shark eco-tourism, which can be an important conservation tool for these species. Australia has a longstanding history of tourism involving whale sharks and great white sharks and an examination of Australian law and policy in shark eco-tourism provides a powerful case study. This article identifies lessons that may be learnt from Australian shark eco-tourism as a first step towards identification of best practice legal strategies that both support the industry and ensure environmental integrity.
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Most arguments invoked so far by the scientific community in favour of shark conservation rely on the ecological importance of sharks, and have little impact on management policies. During a 57-month study, we were able to individually recognise 39 sicklefin lemon sharks that support a shark-feeding ecotourism activity in Moorea Island, French Polynesia. We calculated the direct global revenue generated by the provisioning site, based on the expenses of local and international divers. The total yearly revenue was around USD5.4 million and the 13 sharks most often observed at the site had an average contribution each of around USD316 699. Any one of these sharks represents a potential contribution of USD2.64 million during its life span. We argue that publicising economic values per individual will be more effective than general declarations about their ecological importance for convincing policy makers and fishers that a live shark is more valuable than a dead shark for the local economy. Studies monitoring the potential negative ecological effects of long-term feeding of sharks should, however, be conducted to ensure these are also considered. Besides declarations about the non-consumptive direct-use value of sharks, as promoted by ecotourism, the calculation of their other economic values should also benefit shark conservation.
Ten species of shark belonging to three families were recorded from Aldabra Atoll. Carcharhinus melanopterus and Negaprion acutidens were the most abundant species in the lagoon, while Carcharhinus albimarginatus was the most common shark outside the reef. Twelve hundred sharks of six species were tagged and individual recapture rates varied from 15 to 34%. Some specimens of C. melanopterus were caught up to seven times. All five species for which recapture data were available are restricted in their movements at Aldabra. C. melanopterus in particular is very localized, normally remaining in an area of a few square kilometres. Length increment data obtained from tagging demonstrated a slow growth rate for C. melanopterus, averaging 3.5 cm a-1, with no detectable difference between the growth rates of small and large individuals. Limited data for juvenile Negaprion and C. albimarginatus indicated average growth rates of 12.5 and 8.8 cm a-1 respectively. Population densities calculated for several areas in the lagoon varied from 19 to 198 C. melanopterus per square kilometre. It is suggested that C. melanopterus may be food-limited at Aldabra owing to the intensity of intra- and inter-species competition. C. melanopterus and Negaprion have restricted and almost identical reproductive cycles at Aldabra. C. melanopterus females mature at 110 cm total length and breed every second year giving birth to about four pups after a 10-11 month gestation period. Stomach contents of the more abundant species indicate that fish are the most important item in the diet, except for Nebrius concolor which feeds principally on octopus.
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Flexibility is an important adaptive feature of the foraging behavior of fishes, because most natural environments vary both spatially and temporally. Fish should respond to low levels of food availability by altering their behavior in ways which ensure higher feeding rates, larger feeding territories, and broader diets. It is shown that the gastric sensation of hunger and its rate of change may act as appropriate cues to food availability, and observed hunger-motivated changes in feeding behavior can produce all of these predicted effects. Data are presented to show that juvenile coho salmon (Oncorhynchus kisutch) alter their behavior in an adaptive manner when faced with variable degrees of threat of competition from territorial intruders, and of risk of predation. A review of similar studies on other species supports the generality of these results. Learning is an important mechanism providing behavioral flexibility, and changes in fish feeding behavior with experience are summarized. A graphical model is developed to show that these changes can result in training biases and food specialization. Learning also results in increased feeding rates. The consequences of these observations for the development of refined models of foraging are discussed.
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Research on the development of marine wildlife tourism has tended to focus on the growth and economic importance of the whale-watching industry and its management via self-regulation. However, a number of other species are also utilized as attractions by the marine wildlife tourism industry. There has been increased targeting of a range of, potentially aggressive, shark species as attractions. Areas, such as South Africa [the Great White Shark (Carcharodon carcharias)], Florida and the Caribbean [Tiger sharks (Galeocerdo cuvier), Bull sharks (Carcharhinus leucas), and Caribbean reef sharks (Carcharhinus perezi)] have developed shark-based tourism. This has raised numerous ethical objections, both anthropocentric and biocentric in nature, leading to the intervention by the state in the form of various regulatory frameworks. This article utilizes a case study approach to assess the issues that surround the introduction of state regulation in South Africa and Florida in order to manage the shark-based tourism located there. The article highlights the complex issues facing those tasked with implementing state regulatory frameworks. It concludes that the difficult task of attempting to integrate issues of stakeholder involvement, enforcement, and the balancing of anthropocentric and biocentric concerns results in any framework only being able to be seen as a "best fit" solution for managing shark-based tourism.
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Food handouts to Macaca thibetαnα at Mt. Emei have had dramatic consequences for both man and monkey as tourism has increased over the last decade. Food handouts and human submissive behaviour facilitate beg-robbing by the monkeys, which can be regarded as a mixed conditioning chain. Because of their lack of understanding of primate behaviour and resulting inappropriate responses, many visitors have lost possessions and have been severely frightened or even injured; in fact there have been 10 deaths as an indirect result over that past 8 years. The appropriate human response proved to be the display of dominance to maintain a distance from a beg-robbing monkey. Road-ranging macaques have also been injured or killed by visitors to obtain meat or bones or merely for amusement. Attempts should be made to eliminate the negative effects of food handouts by increasing visitors’ awareness of behavioural and ecological aspects and through aversive conditioning of the macaques.
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Shark feeding is a controversial recreational activity that may alter shark behaviour. In order to investigate possible behavioural changes at the level of the individual, it is necessary to recognise each shark underwater and in a nonintrusive way. In this study, we tested a protocol based on natural marks on fins, and coloured spots and scars on the body to differentiate individual sicklefin lemon sharks. We found that a feeding group, aggregated for 26 months at a northern location off Moorea Island, comprised 32 animals (19 females and 13 males), identified from 2589 observations made over 541 dives. Post-dive photo-identification of individual sharks was a reliable technique, whereas a high level of skill was required to ensure an instantaneous identification underwater. However, direct underwater identification of individual sharks can be of potential use in shark behavioural studies.
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The role of learning in behaviour is well known for many animal taxa, including teleost fishes, insects, birds and mammals. However, its importance to sharks in everyday behavioural processes has rarely been considered. Almost 50 years ago the first learning experiments on sharks were conducted; our first section discusses these studies and places them in a framework of associative and non-associative learning. These experiments showed that sharks were capable of different forms of learning, such as operant and classical conditioning and habituation. Sharks could learn associations as rapidly as other vertebrates and also remember training regimes for several months. However, much of this experimental evidence was based on small sample sizes and few shark orders, such as Carcharhiniformes and Orectobliformes, leaving large gaps in our knowledge of the general learning capabilities of other shark orders. We also examine recent research that has tested for, or inferred learning in behavioural processes. This section reveals that sharks, like teleost fishes use learning to improve prey search and capture to potentially navigate and orientate in their home range and recognize conspecifics, heterospecifics and mates. Learning is also discussed in relation to ecotourism and fisheries. Findings indicated that these activities may lead to conditioning of sharks and that considerable effort should go into investigating what impact this could have on the shark species involved. Finally, we discuss the importance of combining laboratory experiments with field studies, the use of new experimental techniques, the role of model species and research priorities for future work.
Article
The intact ear of the lemon shark,Negaprion brevirostris, is sensitive to sound at low frequencies by electrophysiological criteria. The click-evoked compound action potential of the eighth nerve has a dynamic range of at least 30 dB, with a latency shortening of 120 to 170 μs/dB and an amplitude increase of 4 to 11%/dB relative to a nearly saturated response. The shape of the potential is dependent on the click phase and with the top of the head out of water these potentials are evoked by clicks with air sound pressure levels as low as 19.5 dB re 1 μbar and velocity levels in the water as low as 23 dB re 1 μvar. The calculated displacement thresholds range from 5×10−8 to 4×10−7 cm for this response, overlapping and extending slightly below the thresholds previously reported for whole animals. The frequency sensitivity for this measure of the ear's response also agrees with behavioral data, suggesting that the ear is the primary site for sound detection. Units in the eighth nerve fall into three classes: regularly spontaneous and non-acoustic, irregularly spontaneous and acoustic, and nonspontaneous and acoustic. The best excitatory frequencies for the acoustic units range from 375 Hz down to 31 Hz if not lower, with the majority below 200 Hz. There are two maculae in this ear that are capable of detecting sound. One, the macula neglecta, is a non-otolithic detector composed of two large patches of sensory epithelium that line the walls of the posterior canal duct and extend cilia complexes toward a gelatinous cupula that fills the lumen of the duct. Units in the branch of the eighth nerve that serves this macula are responsive to sound that appears to be transmitted through parietal fossa connective tissue and a dorsal opening in the otic capsule wall. The other sound detector is the macula of the otolithic sacculus. In juvenile lemon sharks this epithelium contains an estimated 300,000 hair cells that extend their cilia toward a large mass of otoconia. It is proposed that these two maculae may detect sound by dissimilar mechanisms that provide different directional responses and possibly different frequency responses and might allow unambiguous sound localization.
Article
The feeding of wildlife has become a popular means by which tourists and tourism operators can facilitate close observation and interaction with wildlife in the wild. These practices are widespread and have a variety of impacts on the wildlife—and on the tourists. Deliberate and long-term provision of food to wildlife has been shown to alter natural behaviour patterns and population levels. It has also resulted in the dependency of animals on the human provided food and their habituation to human contact. Intra- and inter-species aggression has also occurred where wildlife, in their efforts to obtain food, have harmed one another and harmed tourists. There are also important health implications arising from artificial food sources where injury and disease have resulted. While the great majority of cases show negative impacts arising from supplemental feeding of wildlife, this is not always the case. Certainly there are psychological, social and economic benefits that are experienced on the human side of the interaction and, in a limited number of cases, the wildlife can be shown to have benefited as well. The issue of feeding wildlife for tourism is a controversial one with little consensus regarding how it should be managed. Approaches range from complete prohibition, to active promotion and management, to simply ignoring the practices. Little empirical research, inconsistent management and differing views of the role of animals in humans’ lives ensure that this issue will remain a contentious one worthy of further examination and consideration.
Article
Sharks, skates, and rays receive electrical information about the positions of their prey, the drift of ocean currents, and their magnetic compass headings. At sea, dogfish and blue sharks were observed to execute apparent feeding responses to dipole electric fields designed to mimic prey. In training experiments, stingrays showed the ability to orient relative to uniform electric fields similar to those produced by ocean currents. Voltage gradients of only 5 nanovolts per centimeter would elicit either behavior.
Article
The sedimentation constant of an infectious component in ribonucleic acid preparations from foot-and-mouth disease virus has been determined by density-gradient centrifugation. A sedimentation constant of 37 Svedberg units (St) was obtained. On the assumption that the relation between the molecular weight and the sedimentation constant found by Gierer is applicable to our system as well, a value of 3.1 x 106 was calculated for the molecular weight of the infectious component.
Article
Recent studies document unprecedented declines in marine top predators that can initiate trophic cascades. Predicting the wider ecological consequences of these declines requires understanding how predators influence communities by inflicting mortality on prey and inducing behavioral modifications (risk effects). Both mechanisms are important in marine communities, and a sole focus on the effects of predator-inflicted mortality might severely underestimate the importance of predators. We outline direct and indirect consequences of marine predator declines and propose an integrated predictive framework that includes risk effects, which appear to be strongest for long-lived prey species and when resources are abundant. We conclude that marine predators should be managed for the maintenance of both density- and risk-driven ecological processes, and not demographic persistence alone.
Shark attack and the international shark attack file
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Burgess, G. H. (1991). Shark attack and the international shark attack file. In S. H. Gruber (Ed.). Discovering sharks. American littoral society (pp. 101-105). New Jersey: Highlands.
Visual discrimination learning in normal and E
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IEOM (Institut d'Emission d'Outre-Mer) (2016). La Polynésie française en 2013. Papeete, Polynésie française: Institut d'Emission d'Outre-Mer.
Too close for comfort : Contentious issues in human-wildlife encounters
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Shark Feeding is Related to Shark Attacks
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Releasers of attack behaviour pattern in shark and barracuda
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