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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.

Understanding why sharks bite humans is essential for developing strategies to prevent these incidents. Here, we use bite wound characteristics and eye witness descriptions of shark behavior to determine the likely motivation for several bites perpetrated by an oceanic whitetip (OWT) shark Carcharhinus longimanus on an adult female snorkeler off Moorea island (French Polynesia) in October 2019. The victim was snorkeling with others in pelagic waters as part of an organized whale-watching tour when the shark-without any warning behavior-bit her at least three times resulting in severe injuries with substantial loss of soft tissue from the chest and both forearms. The victim survived these injuries thanks to rapid and effective first aid provided by her companions. The sudden, unprovoked and repeated bites with substantial tissue removal are consistent with predatory behavior although the dominance hypothesis cannot be fully ruled out. This would be the first case of a predatory shark bite ever documented in French Polynesia in over 70 years of data collection. Given the routine association of OWT sharks with cetaceans, in-water whale watching activities should adopt appropriate risk management strategies in regions hosting this species of shark.

International audience; Teleost fish that form predictable spawning aggregations and undertake reproductive migrations can be particularly vulnerable to overexploitation. To support community-based management of an artisanal fishery that targets bonefish (Albula glossodonta) spawning aggregations, we used a combination of acoustic telemetry, biological sampling, and remote imagery to reveal the spatiotemporal spawning migrations of bonefish on Anaa Atoll in the Tuamotu Archipelago, French Polynesia. The spawning migrations of bonefish tracked with acoustic telemetry were restricted to the northern section of the atoll, with 99.6% of all detections at offshore spawning habitats occurring on fixed acoustic receivers adjacent to the atoll’s artisanal fish trap complex. Male bonefish undertook spawning migrations more frequently than females and these spawning migrations were common during the Austral winter and fall. The movements of bonefish spawning aggregations coincided with the lunar cycle, as a network analysis revealed an increase in network size and the diversity of habitat use within our acoustic array throughout the duration of the waning moon. Our results highlighted the need for the management of the artisanal trap fishery to prevent the overharvest of bonefish during their peak spawning periods. In response to the spatiotemporal management recommendations derived from this research, the local government established an Educational Managed Marine Area that includes the atoll’s bonefish spawning migratory corridor adjacent to Tukuhora village and a Rahui (i.e., seasonal closure) to improve the sustainability of the fishery.

Data-limited fisheries assessment methods have great potential to help inform small island communities on the status of their fisheries resources. In this paper, we provide a length-based assessment of an artisanal fishery that primarily targets spawning aggregations of Shortjaw Bonefish Albula glossodonta at Anaa Atoll in the Tuamotu Archipelago of French Polynesia. We assessed the length-frequency distribution of the spawning stock across a 3-year period (2016–2018). During this time, male and female Shortjaw Bonefish were fully recruited to the fishery at age 4 and age 5, respectively. Fishing mortality was over two times the range of natural mortality for this species (i.e., 0.21–0.32), and based on these estimates of natural mortality, the annual spawning potential ratio of the population was between 7% and 20% across the sampling years. The majority of the catch was sexually mature, with 78, 95, and 95% of the annual female catch in 2016, 2017, and 2018, respectively, being equal to or greater than the length of first maturity (i.e., 48 cm FL). However, every fisheries indicator and biological reference point suggested that the fishery was overexploited and in need of management intervention. To this aim, the community of Anaa (1) established an Educational Managed Marine Area, which overlaps with the Shortjaw Bonefish migratory corridor adjacent to Tukuhora village and (2) instated a temporal rahui (a traditional conservation method) inside the Educational Managed Marine Area during the peak months of the spawning season.

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.

Although relatively rare, adoptions have been reported in a number of mammals, involving almost exclusively individuals of the same species, and hardly ever between species or across genera. Adoption remains poorly documented and its proximate causes are controversial. Here, we describe a unique case of a cross‐genus adoption within a small community of common bottlenose dolphins (Tursiops truncatus) at Rangiroa Atoll in French Polynesia. It involves a foster female adopting a presumed melon‐headed whale (Peponocephala electra) calf while already mothering its presumed biological offspring. While the inclusive fitness hypothesis can be rejected for this adult female mother, acquisition of parental skills is also unlikely to have driven adoption in parallel to natural motherhood. We argue that the primiparous foster mother’s inexperience and personality may have contributed to factors driving such non‐adaptive behavior. We also propose that the adoptee’s persistence in initiating and maintaining an association with the adult female bottlenose dolphin could have played a major role in the adoption’s ultimate success, as well as the persistence of this cross‐genus adoption after the disappearance of the biological offspring. A brief discussion of adoption and hybridization within the Delphinidae taxon is included to identify how this cross‐genus adoption fits into context of marine mammal parental care.

DNA evidence is routinely used to identify individual predators responsible for attacks on people and livestock in terrestrial settings. However, the use of transfer DNA techniques in aquatic environments20 for similar purposes is a recent development. To date, DNA barcoding has been used successfully to identify shark species depredating fish catches and biting surfboards and neoprene surfaces. In this study we demonstrate the successful DNA barcoding and fingerprinting of individual sharks from transfer DNA collected directly from the wounds of two shark bite victims. The successful use of DNA techniques to identify both species and specific individuals responsible for shark bites opens the door to selective removal of these individuals as an innovative shark bite risk management strategy. This selective approach would be a more effective, eco-responsible, cost-effective and ethical solution for vulnerable taxa than ongoing non-selective culling campaigns.

Identifying the species involved in shark bite incidents is an ongoing challenge but is important to mitigate risk. We developed a sampling protocol to identify shark species from DNA transferred to inanimate objects during bite incidents. To develop and refine the technique, we swabbed shark bite impressions on surfboards and wetsuit neoprene collected under semicontrolled conditions. Methods were tested experimentally and then successfully used to identify the species involved in a real-world shark bite incident. Thirty-two of 33 bite impressions yielded sufficient DNA sequences for species identification, producing barcodes from five test species, including dusky, Galapagos, bull, tiger, and white shark. The latter three species collectively account for a majority of shark bites worldwide. Our method successfully identified the species (Galeocerdo cuvier) responsible for a fatal shark bite on December 8th, 2020 on the island of Maui, from swab samples collected from the victim's surfboard 49 h after the bite incident. Our experimental results demonstrate that shark species can be accurately identified from transfer DNA recovered from bite impressions on surfboards and wetsuit neoprene. The successful use of our method in the real-world incident shows great potential for the practicality of this tool. We recommend DNA swabbing as a routine part of the forensic analysis of shark bites to help identify the species involved in human-shark interactions.

International audience; We used long-term observations of 55 individually identified tiger sharks (Galeocerdo cuvier) at a shark eco-tourism site off Tahiti to estimate the prevalence, retention times and impacts of residual hooks and trailing line resulting from fisheries interactions. Thirty-eight percent of tiger sharks had at least one fisheries interaction resulting in retained hooks during the 8-year observation period. Both stainless-steel and corrodible hooks had a retention half-life of less than 1year, and all corrodible hooks were shed within 2.5 years whereas firmly embedded stainless-steel hooks persisted for at least 7.6 years and are potentially retained for the lifetime of the shark. The presence of residual hooks and trailing line did not impact tiger shark growth suggesting that sharks were able to feed normally despite trailing gear. However, only a single internally-hooked sharks trailing line was observed suggesting their survival may perhaps be lower than externally-hooked individuals. Hook-retention data obtained from this study could be extrapolated to other warm water shark species that are difficult to observe in their natural habitats (e.g. oceanic whitetip shark, Carcharhinus longimanus).

Long-distance movements of sharks within and between islands pose substantial challenges for resource managers working with highly migratory species. When no-take zones do not cover the critical areas that sharks use as part of their lifecycle, exposure to fishing activities can be significant. Shark movements between the Marine Protected Areas (MPAs) of the Eastern Tropical Pacific (ETP) have been studied for several years, however little is known about the strength of connectivity between these islands. We analyzed the extensive MigraMar ultrasonic telemetry dataset to assess how Galapagos sharks (Carcharhinus galapagensis) and silky sharks (Carcharhinus falciformis) use different islands as stepping-stones during their migrations within the Revillagigedo National Park and other ETP islands. Of the 66 sharks monitored, 63.5% moved within the same island, 25.4% between two islands or more and only 10.1% across different MPAs. A C. falciformis tagged in Roca Partida Island, Revillagigedo, travelled to Clipperton Atoll and another one tagged in Darwin Island travelled to the atoll on two different years. The largest movement of C. galapagensis was accomplished by a shark tagged at Socorro Island, Revillagigedo, later detected at Clipperton and finally recorded in Darwin Island, Galapagos. This last path was in fact, one of the longest movements ever recorded for the species. Although long-distance dispersion was not common, our results highlight the need for co-operation between different countries to ensure adequate protection for sharks in the form of swimways and other conservation tools in the ETP.

An accurate assessment of the biting shark size is paramount for better understanding the agonistic behavior of a species toward humans. The gray reef shark is involved in many accidental bites. Based on the capture of 35 gray sharks, we calculated the algorithm that allows the assessment of the shark size, through the interdental distance (IDD) inferred from teeth marks on human wounds. Our results show a negative allometric relationship and that IDD calculated from imprints perpetrated by the upper jaw are globally similar with those from the lower jaw, in spite of heterodonty. We applied our findings to two cases of accidental bites by this species. Both of the victims had declared that the shark length was “at least 2 m”. Based on our algorithm, the assessment of the shark TL was approx. 180 and 160 cm, respectively, which correspond to an overestimation of ≥20% by the victims.

International audience; Fisheries management requires knowledge on the population dynamics of exploited stocks. To that end, the present study used a mark–recapture approach to characterise the population demographics of roundjaw bonefish Albula glossodonta (Forsskål) and their interaction with a data-limited fishery on Anaa Atoll in the Tuamotu Archipelago of French Polynesia. Over the course of the study, 2,509 bonefish were tagged and12.3% were recaptured. The L ∞ of bonefish was estimated at 71 cm fork length (FL) with a K of 0.17, based on changes in FL between capture events. Artisanal fish traps located in the migratory corridors of the atoll accounted for 94% of recaptures and these movements occurred during the waning moon. Fishing mortality increased as bonefish reach sexual maturity, recruiting to the trap fishery at age 4 with the onsetof spawning behaviour. Bonefish abundance between ages 3 and 5 was estimated to be 29,079 individuals. This case study demonstrated the utility of mark–recapture in filling knowledge gaps that impede the management of data-limited fisheries. Ultimately, these results supported the creation of an Educational Managed Marine Area and the resurgence of rahui (seasonal closure) to manage this fishery.

Bonefishes Albula spp. are important components of subsistence fisheries and lucrative sport fishing industries throughout their circumtropical distribution. In Oceania, however, Albula spp. have historically been overexploited and there is a growing need to balance the demands of competing fishing sectors, making the description of their life history a regional priority. To this aim, we collected biological samples from Albula spp. of Anaa atoll, French Polynesia, to identify the species that compose the stock and estimate their life-history parameters including age, growth, reproduction and natural mortality. Our results indicate that Albula glossodonta is the species of bonefish present, with a maximum age that is below the, 20 year longevity of the genus (8 years in males and 10 years in females). Differential growth patterns existed between the two sexes (L∞ = 58, 78 cm fork length (LF ) and K = 0.38, 0.21 for males and females, respectively). Males attained sexual maturity at 43 cm LF (c. 3 years) whereas females matured at 48 cm LF (c. 4 years) and oocyte production was significantly related to body mass, with a maximum batch fecundity of 1,133,767 oocytes in a 4406 g (70 cm LF ) female. The gonado-somatic index of harvested fishes indicated that the spawning season extends from March through September. Based on the observation of a, 20 year bonefish at the proximate Tetiaroa Atoll and several empirical models, estimates of natural mortality ranged from 0.21 to 0.68; however, an estimate of 0.21 was deemed most appropriate. This information facilitated the resurgence of a Rahui (temporary fishing closure) and community-based management to protect A. glossodonta during a critical portion of their spawning season and in this context our results provide an important demographic baseline in evaluating the recovery of this fishery.

International audience; Coral reef fisheries provide important ecosystem services to coastal communities, yet in the Pacific Islands, many of these contemporary fisheries are threatened by overexploitation. Historically, Pacific Island societies successfully utilized community-based management and spatial temporal closures to regulate the harvest of marine resources. In recognition of their past success these actions are currently being reemployed throughout the region. However, in many communities, innovative approaches may be needed to revitalize such practices and adapt traditional management to contemporary societal needs and expectations. This study presents the case of Anaa Atoll, a remote Pacific Island in the Tuamotu Archipelago of French Polynesia, and the community’s efforts to conserve a culturally important but overexploited bonefish (Albula glossodonta) fishery. Ultimately, fisheries research, education, and the creation of Aire Marine Educative (a marine area that is managed by a local primary school) were successful in building social cohesion and supporting the renaissance of rahui (a traditional form of restricting access to resources and or territories) to manage this fishery. On March 1st, 2019, the community of Anaa reinitiated this tradition for the first time in centuries. Based on these experiences, and an ensuing increase in the Spawning Potential Ratio of the bonefish stock, it is proposed that nationally recognized local management systems that incorporate fisheries research, youth education, and the cultural practices of communities should be supported in the marine policies of the Pacific Islands and beyond.

In French Polynesia, both currently recognized manta ray species, Mobula alfredi and M. birostris, are observed. Despite being an important cultural asset and generating significant economic benefits through manta ray watching tourism, published data on the ecology and threats to these species in the region are scarce. Based on an 18-year dataset of sighting records collected by citizen scientists and during two scientific expeditions, this study provides the first insights into the population characteristics and regional distribution of the two manta ray species in French Polynesia. A total of 1347 manta ray photographs (1337 for M. alfredi and 10 for M. birostris) were examined for the period January 2001–December 2017, with photo-identification techniques leading to the successful identification of 317 individual M. alfredi and 10 individual M. birostris throughout the Society, Tuamotu and Marquesas Islands. We provide the first confirmation of sympatric distribution of both species in the Society Islands. Our results highlight strong and long-term site fidelity of M. alfredi individuals to certain aggregation sites (> 9 years for 16 individuals) and reveal some degree of connectivity between populations, with 10 individuals recorded moving between islands located up to 50 km apart. Analysis of photographs of individuals bearing sub-lethal injuries (n = 68) suggests that M. alfredi are more likely to be injured at inhabited islands (Maupiti or Bora Bora; 75% of all injured individuals) than at uninhabited islands, with 75% of injuries related to boat propeller strikes and fishing gear entanglements. Our findings emphasize the need for further research to allow for a comprehensive evaluation of population structure, size and threats to manta rays in this region.

Baited 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

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content., Workshop funding was granted by the University of Western Australia (UWA) Oceans Institute, the Australian Institute of Marine Science (AIMS), and King Abdullah University of Science and Technology (KAUST). A.M.M.S. was supported by Australian Research Council Grant DE170100841 and an Indian Ocean Ocean Marine Research Centre (UWA, AIMS, Commonwealth of Scientific and Industrial Research Organisation) fellowship. J.P.R., V.M.E., and J.F.G. were supported by Agencia Estatal de Investigación (AEI, Spain) and Fondo Europeo de Desarrollo Regional (FEDER) through project Spatiotemporality in Sociobological Interactions, Models and Methods (SPASIMM) (FIS2016-80067-P AEI/FEDER, European Union), and by research funding from KAUST. J.P.R. was supported by Ministerio de Educación, Cultura y Deporte (Formación de Profesorado Universitario Grant, Spain). D.W.S. was supported by the UK Natural Environment Research Council and Save Our Seas Foundation. N.Q. was supported by Fundação para a Ciência e Tecnologia (Portugal). M.M.C.M. was supported by a Coordenação de Aperfeiçoamento de pessoal de Nível Superior fellowship (Ministry of Education).

We present a case of a non-provoked fatal shark attack on a 15-year old male kitesurfer in New Caledonia. The victim lost his board and was pulled by the sail along the water surface in a reef passage when a shark attacked. The shark inflicted at least two bites on the left leg, including a severe one around the knee, resulting in a quick hypovolemic shock that was fatal. The analysis of one of these bites indicated that a 2.8 m TL (est. length) tiger shark was responsible for this attack. The features of the attack are consistent with those of a predator response to a surface feeding stimulus.

Artisanal fisheries are critically important to food security and economic opportunity in coastal communities throughout the developing world. However, the dynamics of these fisheries are poorly understood, and a basic understanding of the gear types and species harvested, is required to promote effective fisheries management. To this aim, we surveyed artisanal fishers at Anaa atoll from May 14th, 2016 to May 19th, 2017 and described the selectivity and exploitation of the fishery's dominant species. The harvested marine life included 98 species from 31 families, which were captured with seven gear types including artisanal fish traps, monofilament nets, spear guns, handlines, pole and line, hand, and harpoons. Bonefish (Albula glossodonta) were the most abundant species and comprised 25% of the overall catch, followed by Chaetodon auriga, Kuhlia sandvicensis, Lutjanus fulvus, and Chanos chanos. Artisanal fish traps and spearguns harvested a higher proportion of overexploited fishes, captured a more diverse range of species, and removed the most biomass from the atoll. An analysis of the size distribution of harvested fishes, with length-based catch curves, indicates that species with high natural mortality rates such as Chanos chanos and Selar crumenophthalmus were underexploited. While in contrast, slow growing, late maturing, and long-lived species such as Naso lituratus and Epinephelus polyphekadion were overexploited. The results of this research provided the community with the basis for making local management decisions regarding their fisheries resources, including the development of an Educational Managed Marine Area and a seasonal closure of the artisanal trap fishery to allow for movement, predominantly A. glossodonta during their offshore spawning migrations.

Conservation of threatened large sharks and management of shark-human interactions requires an under- standing of shark occurrence and movement patterns. Here, we present the first catch, movement and behaviour data of adult bull sharks, Carcharhinus leucas, in New Caledonia. Amongst six adult C. leucas tagged with passive acous- tic tags, four females were caught in coastal waters while males were only found at an isolated oceanic barrier coral reef over 100 km from the nearest river mouth. Two females were monitored in the southern New Caledonia lagoon for 707 and 208 days respectively and displayed classical transient behaviour and sporadic short-term residency around a coastal reef bay, with movements in and out a river detected prior to spring. Adult C. leucas in New Caledonia may develop a sex-based spatial segregation with an atypical presence of adult males in oceanic environments, probably influenced by the unique estuarine-marine continuum of the New Caledonian great lagoon.

We present the case of a non provoked fatal shark attack on a 19-year old male surfer in New Caledonia. Several severe bites removed the right arm and all flesh from the right thigh, provoking a quick hypovolemic shock that was fatal. The information provided by a witness and the analysis of a partial bite on the right calf allowed us to identify a 2.7 m TL (est. length) white shark as responsible for this attack. The features of the attack are consistent with a young predator motivated by hunger and the development of its predatory skills.

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 17.4 m 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 36 h. The fat slicks from the carcass attracted further Tiger Sharks which arrived after an additional 24 h. 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 4 m TL) participating in the ...

International audience; The extent of the global human footprint [ 1 ] limits our understanding of what is natural in the marine environment. Remote, near-pristine areas provide some baseline expectations for biomass [ 2, 3 ] and suggest that predators dominate, producing an inverted biomass pyramid. The southern pass of Fakarava atoll—a biosphere reserve in French Polynesia—hosts an average of 600 reef sharks, two to three times the biomass per hectare documented for any other reef shark aggregations [ 4 ]. This huge biomass of predators makes the trophic pyramid inverted. Bioenergetics models indicate that the sharks require ∼90 tons of fish per year, whereas the total fish production in the pass is ∼17 tons per year. Energetic theory shows that such trophic structure is maintained through subsidies [ 5–9 ], and empirical evidence suggests that sharks must engage in wide-ranging foraging excursions to meet energy needs [ 9, 10 ]. We used underwater surveys and acoustic telemetry to assess shark residency in the pass and feeding behavior and used bioenergetics models to understand energy flow. Contrary to previous findings, our results highlight that sharks may overcome low local energy availability by feeding on fish spawning aggregations, which concentrate energy from other local trophic pyramids. Fish spawning aggregations are known to be targeted by sharks, but they were previously believed to play a minor role representing occasional opportunistic supplements. This research demonstrates that fish spawning aggregations can play a significant role in the maintenance of local inverted pyramids in pristine marine areas. Conservation of fish spawning aggregations can help conserve shark populations, especially if combined with shark fishing bans.

International audience; Based on new photographs of the wound, Tirard et al. (2015) tried to demonstrate that the shark involved in a fatal attack on a human in Lifou in 2007 had homodont teeth and that it sawed the femur instead of directly cutting it, promoting the hypothesis that it was a tiger shark instead of a white shark. They also contested the data provided by the direct witness of the attack about the behaviour of the shark, specific to this former species. The evidences they provide are not convincing and, based on the absence of tissue loss and description of a jumping behaviour, we still believe that it was a single bite-and-spit attack by a white shark.

Ciguatera fish poisoning (CFP) is a common intoxication associated with the consumption of reef fish, which constitutes a critical issue for public health in many countries. The complexity of its epidemiology is responsible for the poor management of the risk in tropical fish markets. We used the example of the Noumea fish market in New Caledonia to develop a cost-effective methodology of assessing the CFP risk. We first used published reports and the knowledge of local experts to define a list of potentially poisonous local species, ranked by their ciguatoxic potential. Based on two 1-month surveys in the market, conducted in winters 2008 and 2009, we then calculated the consolidated ratio of biomass of potentially poisonous species vs. total biomass of fish sold on the market. The prevalence of high CFP-risk species in the market was 16.1% and 18.9% in 2008 and 2009, respectively. The most common high CFP risk species were groupers (serranids), king mackerels (scombrids), snappers (lutjanids), barracudas (sphyaraenids), emperors (lethrinids) and wrasses (labrids). The size (age) of the fish also plays a critical role in the potential ciguatoxic risk. According to proposals of average size thresholds provided by experts for high-risk species, we were also able to assess the additional risk induced by the sale of some large fish on the market. The data collected both from experts and from the market allowed us to develop a cost-effective proposal for improving the management of the CFP risk in this market. However, the successful implementation of any regulation aiming to ban some specific species and sizes from the market, with an acceptable economical impact, will require the improvement of the expertise in fish identification by public health officers and, ideally, the commitment of retailers.

International audience; The feeding of marine predators is a popular means by which tourists and tour operators can facilitate close observation and interaction with wildlife. Shark-feeding has become the most developed provisioning activity around the world, despite its controversial nature. Amongst other detrimental effects, the long-term aggregation of sharks can modify the natural behaviour of the animals, potentially increase their aggression toward humans, and favour inbreeding. During 949 diving surveys conducted over 44 mo, we investigated the ecology and residence patterns of 36 photo-identified adult sicklefin lemon sharks Negaprion acutidens. The group contained 20 females and 16 males. From this long-term survey, we identified 5 different behavioural groups that we described as 'new sharks' (7), 'missing sharks' (4), 'resident sharks' (13), 'unpredictable sharks' (5) and 'ghost sharks' (7). In spite of movements in and out of the area by some males and females, which were probably related to mating, the general trend was that residency significantly increased during the study, particularly in males, showing a risk of inbreeding due to the reduction of shark mobility. Intra- and interspecific aggression was also witnessed, leading to an increased risk of potentially severe bites to humans. Our findings suggest the need for a revision of the legal framework of the provisioning activity in French Polynesia, which could include a yearly closure period to decrease shark behavioural modifications due to long-term shark-feeding activities.

Governments, non-government organizations, and other stakeholders are striving to develop practices, policies, and vehicles to make the tropical marine ornamental trade sustainable. Small-scale fisheries based on post-larval capture and culture (PCC) promise to contribute to this goal by (1) removing the risk of damaging corals (inherent in harvesting adults of target species established on reefs) by collecting post-larvae with light traps, nets, and purpose-built temporary shelters as they settle from the plankton to the substrate; and (2) translating the high mortality of post-larvae at settlement into high rates of survival in culture. Possible concerns about overfishing of post-larvae, harvesting the juveniles after they have run the gauntlet of predation at settlement, and the large proportion of bycatch can be eliminated or greatly alleviated by restricting the size and quantity of fishing gear, designing it to retain bycatch alive, and releasing bycatch at times and places that minimize predation. ...

The present paper analyzes data collected between 2001 and 2002 on 81 reef fish species targeted by fishers at 5 sites in the Kingdom of Tonga (South Pacific). We first ranked the sites with respect to fishing pressure using two independent methods: (i) Tongan demography and reef surfaces available for fishing, and (ii) the differential effects of fishing on the whole set of 81 species grouped by their life history traits (LHT). We then focused on Parrotfish (Scaridae), which are heavily targeted in coral reef fisheries. We used the identified gradient of fishing pressure to study the effect of fishing on the community structure and test the hypothesis of "shifting dominance" amongst the 20 Scarid species present in the surveys. In addition to the classical effect of decreasing fish size in a family strongly targeted by fishers, the shifting dominance phenomenon includes a decrease in the abundance of the large-bodied and highly targeted species, favouring their replacement by smaller-bodied species from the same family, which are less impacted by fishing. In a context of interspecific competition amongst Scarids, the stress of fishing appears as a factor favouring the replacement of species with large maximum size, and LHT promoting low resilience, by smaller species with the opposite attributes. The discussion focuses on the various processes that can explain the shifting dominance phenomenon. The total density of resilient species, which increased along the gradient of increasing fishing pressure, can be used as an indicator of the over-exploitation of fish communities for reef fisheries management.

International audience

The use of olfactory stimuli and the provision of food are a common practice to prompt artificial aggregations of emblematic wild species and ensure the economic viability of the wildlife-watching industry. Several elasmobranch species have been targeted by such operations in a variety of locations for over 4 decades. A recent review succinctly addressed the potential effects of shark diving tourism, including shark provisioning, on shark individual behavior and ecology, but the paucity of data on the ecology of elasmobranchs precluded general statements. By using a functional framework, we reviewed the findings of the 22 available studies that investigated the behavioral, physiological, and ecological response of 14 shark and 3 ray species targeted by artificial provisioning. Focusing on the underlying processes that rule the response of targeted elasmobranch species, we report further effects acting beyond the individual scale. We suggest that the most commonly described alterations of individual movement patterns have cascading effects through the group and community scales, ultimately resulting in altered health condition and individual behavior toward humans. We conclude by stressing the potential for provisioning activities to support the investigation of complex ecological and behavioral processes in elasmobranchs.

Habitat characteristics play a critical role in structuring reef fish communities subjected to fishing pressure. The line intercept transect (LIT) method provides an accurate quantitative description of the habitat, but in a very narrow corridor less than 1 m wide. Such a scale is poorly adapted to the wide-ranging species that account for a significant part of these assemblages. We developed an easy-to-use medium scale approach (MSA), based on a semi-quantitative description of 20 quadrats of 25 m 2 (500 m 2 in total). We then simulated virtual reef landscapes of different complexities in a computer, on which we computed MSA using different methods of calculation. These simulations allowed us to select the best method of calculation, obtaining quantitative estimates with acceptable accuracy (comparison with the original simulated landscapes: R 2 ranging from 0.986 to 0.997); they also showed that MSA is a more efficient estimator than LIT, generating percentage coverage estimates that are less variable. A mensurative experiment based on thirty 50-m transects, conducted by three teams of two divers, was used to empirically compare the two estimators and assess their ability to predict fish–habitat relationships. Three-factor multivariate ANOVAs (Teams, Reef, Methods) revealed again that LIT produced habitat composition estimates that were more variable than MSA. Canonical analyses conducted on fish biomass data successively aggregated by mobility patterns, trophic groups, and size classes, showed the higher predictive power of MSA habitat data over LIT. The MSA enriches the toolbox of methods available for reef habitat description at intermediate scale (b1000 m 2 ), between the scale where LIT is appropriate (b100 m 2 ) and the landscape approach (N1000 m 2 ).

International audience; This study determined the movements of a Giant Grouper, Epinephelus lanceolatus, in which an acoustictag was surgically implanted and monitored by an array of six VR2W acoustic receiver units from August 2010 toJanuary 2013 in the remote, uninhabited Chesterfield Islands, Coral Sea (800 km West of New Caledonia). Our datarevealed a home reef area (residency rate of 44.9%) with an increased activity revealed by movements at dawn anddusk toward and between two adjacent reef passages, probably for foraging. The fish was absent from its residentreef between October and December 2010 and 2012, corresponding to the time known for spawning aggregationsof this species in New Caledonia. A skipped spawning seems to have occurred in 2011. We hope these data will becomplemented in the future by locating the spawning site or sites and thus provide adequate conservation measures.The Coral Sea links two World Heritage Sites, the Australian Great Barrier Reefs and the New Caledonian coral reefs.It would be fitting to create a Marine Protected Area for the Chesterfield Islands between these two major conservationareas of the sea.

Times Cited: 0 0; International audience; For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics of blacktip reef sharks, Carcharhinus melanopterus; one of the most abundant reef-associated sharks and the apex predator of many shallow water reefs of the Indian and Pacific Oceans. Our sampling includes 4 widely separated locations in the Indo-Pacific and 11 islands in French Polynesia with different levels of coastal development. Four-teen microsatellite loci were analysed for samples from all locations and two mitochondrial DNA fragments, the control region and cytochrome b, were examined for 10 locations. For microsatellites, genetic diversity is higher for the locations in the large open systems of the Red Sea and Australia than for the fragmented habitat of the smaller islands of French Polynesia. Strong significant structure was found for distant locations with F-ST values as high as similar to 0.3, and a smaller but still significant structure is found within French Polynesia. Both mitochondrial genes show only a few mutations across the sequences with a dominant shared haplotype in French Polynesia and New Caledonia suggesting a common lineage different to that of East Australia. Demographic history analyses indicate population expansions in the Red Sea and Australia that may coincide with sea level changes after climatic events. Expansions and flat signals are indicated for French Polynesia as well as a significant recent bottleneck for Moorea, the most human-impacted lagoon of the locations in French Polynesia.

Each summer the presence of large concentrations of bait fish in the area of the central Azores Islands gives rise to mixed-species feeding aggregations usually at dawn and dusk. The encircling of prey initiated by common dolphins (Delphinus delphis), often mixed with spotted dolphins (Stenella frontalis), results in the formation of a compact ‘ball’ of several thousands prey fish close to the surface. Other dolphins, in particular the bottlenose (Tursiops truncatus), also eat the prey fish, whose high concentration makes them easy to capture. Large tunas (Thunnus thynnus, Thunnus albacares) sometimes participate in the phenomenon. Seabirds (mainly cory’s sheawaters, Calonectris diomedea borealis) are always present throughout the few minutes during which the entire collective food hunt takes place. A model of the phenomenon, based on 15 observations, is proposed. It comprises 4 stages: a preparation phase, an intensification phase, a mature phase, and a dispersion phase. These observations allow a better understanding of the tuna-dolphin aggregation process. They show that it is the tunas that generate and beneficiate from the aggregation with dolphins, rather than the contrary.

Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark–human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a priority for future research.

The population dynamics of shark species are generally poorly described because highly mobile marine life is challenging to investigate. Here we investigate the genetic population structure of the blacktip reef shark (Carcharhinus melanopterus) in French Polynesia. Five demes were sampled from five islands with different inter-island distances (50-1500 km). Whether dispersal occurs between islands frequently enough to prevent moderate genetic structure is unknown. We used 11 microsatellites loci from 165 individuals and a strong genetic structure was found among demes with both F-statistics and Bayesian approaches. This differentiation is correlated with the geographic distance between islands. It is likely that the genetic structure seen is the result of all or some combination of the following: low gene flow, time since divergence, small effective population sizes, and the standard issues with the extent to which mutation models actually fit reality. We suggest low levels of gene flow as at least a partial explanation of the level of genetic structure seen among the sampled blacktip demes. This explanation is consistent with the ecological traits of blacktip reef sharks, and that the suitable habitat for blacktips in French Polynesia is highly fragmented. Evidence for spatial genetic structure of the blacktip demes we studied highlights that similar species may have populations with as yet undetected or underestimated structure. Shark biology and the market for their fins make them highly vulnerable and many species are in rapid decline. Our results add weight to the case that total bans on shark fishing are a better conservation approach for sharks than marine protected area networks.

The case of a fatal, unprovoked shark attack is reported and analyzed. The incident took place on the 30th of September 2007, in the lagoon of Luengoni Bay, Lifou Island (Loyalty Islands, New Caledonia). A young French woman who was snorkeling was severely bitten on the right thigh and died of hemorrhage. An analysis based in particular on the size and color of the shark, the characteristics of the wounds, and the behavior of the shark before and after the bite suggests that the aggressor was a great white shark, Carcharodon carcharias.

Human pressures have put many top predator populations at risk of extinction. Recent years have seen alarming declines in sharks worldwide, while their resilience remains poorly understood. Studying the ecology of small populations of marine predators is a priority to better understand their ability to withstand anthropogenic and environmental stressors. In the present study, we monitored a naturally small island population of 40 adult sicklefin lemon sharks in Moorea, French Polynesia over 5 years. We reconstructed the genetic relationships among individuals and determined the population's mating system. The genetic network illustrates that all individuals, except one, are interconnected at least through one first order genetic relationship. While this species developed a clear inbreeding avoidance strategy involving dispersal and migration, the small population size, low number of breeders, and the fragmented environment characterizing these tropical islands, limits its complete effectiveness.