Carcharias Taurus Research Articles

Habitat selection of a coastal shark species estimated from an autonomous underwater vehicle

Quantifying habitat selection in marine organisms is challenging because it is diffi- cult to obtain species location information with multiple corresponding habitat measurements. In the ocean, habitat conditions vary on many spatiotemporal scales, which have important conse- quences for habitat selection. While macroscale biotic and abiotic features influence seasonal movements (spatial scales of 100�1000 km), selectivity of conditions on mesoscales (1�100 km) reflects an animal's response to the local environment. In this study, we examined habitat selec- tivity by pairing acoustic telemetry with environmental habitat parameters measured by an autonomous underwater vehicle (AUV), and demonstrate that migrating sand tiger sharks Carcharias taurus along the East Coast of the USA did not randomly use the coastal environment. Of the variables examined, we found evidence to suggest that sand tigers were selecting their habitat based on distance to shore, salinity, and colored dissolved organic matter (CDOM). Notably, temperature was not predictive of habitat use in our study. We posit that during their coastal migration, sand tigers select for specific mesoscale coastal habitats that may inform navi- gation or feeding behaviors. To our knowledge, this is the first empirical measure of mesoscale habitat selection by a coastal marine organism using an AUV. The applications of this method extend beyond the habitat selectivity of sand tigers, and will prove useful for future studies com- bining in situ observations of marine habitats and animal observations.

Structure and mechanical properties of normal and anomalous teeth in the sand tiger shark Carcharias taurus.

This study reports and characterises an anomalous condition in teeth of captive sand tiger sharks Carcharias taurus . Abnormal shed teeth from captive sand tiger sharks which were soft to the touch were structurally and chemically characterised and compared to the structure and composition of normal teeth of the species. Normal specimens exhibited the expected tooth morphology with a well-developed tooth crown consisting of a central cusp and two lateral cusplets with smooth and sharp margins, while in the anomalous specimens the crown height was much reduced and the overall shape did not follow this pattern. Lateral cusplets were also considerably reduced in size and with blunt margins. Scanning electron images showed a distinct absence of crystalline structures in the anomalous specimens. Raman microscopy analysis confirmed the low volume of fluoroapatite in the outer layers of the anomalous teeth, while the composition of the inner layers corresponding to dentine was comparable to the normal tooth specimens. Nanoindentation-derived mechanical properties showed significant differences between the anomalous and normal teeth. The mean values for enameloid elastic modulus and hardness of all three normal teeth were 75.92±3.4 GPa and 3.27±0.41 GPa, respectively. On the other hand, mean values of elastic modulus and hardness for anomalous teeth were 7.81±3.27 GPa and 0.39±0.25 GPa, respectively. However, mechanical property values of the dentine of normal and anomalous teeth were similar. The mean values of dentine elastic modulus and hardness of the normal teeth were 25.66±2.14 GPa and 0.89±0.01 GPa, respectively, while mean values for the anomalous teeth were 25.34±1.54 GPa and 0.83±0.03 GPa. Although the morphological, mechanical and chemical differences between the normal and anomalous teeth are quite evident, establishing the causes of this condition are not possible at this stage.

Serum biochemical reference intervals for free‐living Sand Tiger sharks (Carcharias taurus) from east Australian waters

Sharks are top-order predators in ocean food chains and the star attractions in aquaria worldwide. Unfortunately, blood biochemistry reference intervals (RI) have been determined for few species. The study aims to establish serum biochemical RI for free-living Sand Tiger sharks (Carcharias taurus) off eastern Australia. Thirty-seven sharks were captured and their sex, length, weight, reproductive maturity, and health status were recorded. After blood collection, serum analytes were quantified using standard analytical and statistical methods. Reference intervals, means, medians, and 90% confidence intervals were generated. Physiologic data from live and necropsied sharks were used to enhance the study results. Thirty healthy sharks were included in the study. Albumin could not be detected. With the exception of ALP activity, values were unaffected by sex, length, weight, age, and life-history stage. The means (RI) were: sodium 258 (249-267) mmol/L, potassium 5.0 (4.3-5.7) mmol/L, chloride 242 (227-257) mmol/L, inorganic phosphate 1.8 (1.7-2.0) mmol/L, total calcium 3.9 (3.3-4.4) mmol/L, magnesium 1.9 (1.6-2.2) mmol/L, glucose 2.7 (2.2-3.2) mmol/L, urea 377 (360-394) mmol/L, ALP 20 (8-31) U/L, ALT 3U/L (no RI), AST 29 (13-45) U/L, CK 42 (5-79) U/L, total protein 30 (24-36) g/L, triglyceride 0.3 (0.1-0.6) mmol/L, cholesterol 1.4 (0.9-2.1) mmol/L, creatinine 32μmol/L (no RI), total bilirubin 1.5μmol/L (no RI), and osmolarity 1082 (1027-1136) mmol/L. These preliminary RI will assist with the clinical evaluation and treatment of captive and free-living Sand Tiger sharks worldwide. Studies with more animals will increase the precision of upper and lower reference limits.

The current status and management of South Africa's chondrichthyan fisheries

Chondrichthyans (sharks, skates, rays and chimaeras) are captured in many marine fisheries. Management and research efforts directed at chondrichthyan fishing are often neglected because of low product value, taxonomic uncertainty, low capture rates, and harvesting by multiple fisheries. In South Africa's diverse fishery sectors, which include artisanal as well as highly industrialised fisheries, 99 (49%) of 204 chondrichthyan species that occur in southern Africa are targeted regularly or taken as bycatch. Total reported dressed catch for 2010, 2011 and 2012 was estimated to be 3 375 t, 3 241 t and 2 527 t, respectively. Two‑thirds of the reported catch was bycatch. Regulations aimed at limiting chondrichthyan catches, coupled with species‑specific permit conditions, currently exist in the following fisheries: demersal shark longline, pelagic longline, recreational line, and beach‑seine and gillnet. Limited management measures are currently in place for chondrichthyans captured in other South African fisheries. Catch and effort dataseries suitable for stock assessments exist for fewer than 10 species. Stock assessments have been attempted for five shark species: soupfin Galeorhinus galeus, smoothhound Mustelus mustelus, white Carcharodon carcharias, spotted ragged‑tooth Carcharias taurus, and spotted gully Triakis megalopterus. Fishery‑independent surveys and fishery observer data, which can be used as a measure of relative abundance, exist for 67 species. Compared with most developing countries, South African shark fishing is relatively well controlled and managed. As elsewhere, incidental capture and bycatch remain challenges to the appropriate management of shark species. In 2013, South Africa's National Plan of Action for the Conservation and Management of Sharks (NPOA‑Sharks) was published. Implementation of the NPOA‑Sharks should help to improve chondrichthyan management in the near future.

Seasonality, behaviour and philopatry of spotted ragged‑tooth sharks Carcharias taurus in Eastern Cape nursery areas, South Africa

Spotted ragged‑tooth sharks Carcharias taurus occur along the southern and eastern coasts of South Africa. We report on movements of juveniles and adults within a known nursery area on the Eastern Cape coast using acoustic telemetry. The focus area of the study was Algoa Bay, where six VEMCO VR2 ultrasonic receivers were placed at known shark aggregation sites. An additional receiver was placed at Thunderbolt Reef, approximately 2 km south‑ west of Cape Recife, the south‑western tip of Algoa Bay. Single receivers were also deployed at Port Alfred and East London, some 45 and 170 km north‑east of Algoa Bay, respectively. VEMCO acoustic V16 tags were either surgically implanted (n = 37) or attached externally using dart heads (n = 6) between January 2003 and March 2006. Surgically implanted tags were recorded over multiple months and years, whereas external tags were probably lost shortly after tagging because they were detected for very short periods. Sharks moved extensively between the sites and revisited monitored reefs over time‑periods of months and years, demonstrating philopatry. Departures from and arrivals at reefs were more frequently recorded at sunset and sunrise, respectively. Sharks were detected throughout the year but they spent more time at aggregation sites during summer and autumn, indicating seasonal abundance in agreement with previous findings. Movements away from study reefs were attributed to either foraging or movements to other reefs. Despite extensive movements around the bay and beyond, both juveniles and adults exhibited philopatry to the study area over multiple years.

Behaviour of aggregated grey nurse sharks Carcharias taurus off eastern Australia: similarities and differences among life-history stages and sites

Stereo-video photogrammetry was used to document swimming and non-swimming behaviours of various life-history stages of the grey nurse shark Carcharias taurus at 8 east Aus- tralian aggregation sites (during daylight) in the absence of scuba diving tourism and fishers. Swimming behaviours included hovering, milling, and active swimming with significantly greater milling. Rates of movement were least during milling and greatest for active swimming. Pectoral fins were held 20 to 24° below horizontal, which was consistent with holding positions reported in shark swimming studies. Significantly lower caudal fin positions during hovering probably minimised forward propulsion. Tail-beat frequency decreased significantly with increasing total length and was likely due to greater propulsion from larger caudal fins. Low activity indicated that sharks minimised energy expenditure when aggregated, which was associated with migratory and reproductive behaviours. Significantly different pectoral fin positions among sites likely resulted from differing navigational requirements. Non-swimming behaviours were infrequent. Chafing, gill puff, head snapping and palatoquadrate protrusion were generally categorised as grooming behaviour. One gill puff sequence and all but one rapid withdrawal event were cate- gorised as 'flight'-response agonistic behaviour. The remaining rapid withdrawal and stand back were to avoid collision and categorised as swimming behaviour. The absence of 'fight'-response agonistic behaviour was consistent with previous descriptions of the species as docile. This partial ethogram will enhance ecological understanding, assist assessment and management of diving tourism, and contribute to the recovery and long-term conservation of this critically endangered species.

Migratory patterns and habitat use of the sand tiger shark (Carcharias taurus) in the western North Atlantic

Globally, population declines for the sand tiger shark (Carcharias taurus) have resulted in calls for informed management of populations, including in the western North Atlantic, where they have been listed as a Species of Concern by NOAA Fisheries. However, information on movements and habitat use, critical for informed management of this sand tiger population, is limited. We investigated horizontal and vertical movements of sand tigers along the US east coast using pop-up archival satellite transmitters, supplemented by acoustic telemetry. Thirteen sand tiger sharks were tagged with satellite and acoustic transmitters in Delaware Bay in late August and early September 2008. Ten of these provided satellite data for horizontal tracks using a Kalman filter. Males left Delaware Bay in autumn and moved south along the continental shelf until reaching waters off North Carolina. Females moved east to waters near the edge of the continental slope. Average depth of males was positively correlated with shark size. All individuals spent at least 95% of their time in waters of 17–23°C. Sand tiger sharks appear most susceptible to fisheries in November and December. Slight expansion of the boundaries and timing of an existing shark-directed bottom longline area closure would likely reduce by-catch of sand tiger sharks and enhance recovery of the stock.

First records of the grey nurse shark Carcharias taurus (Lamniformes: Odontaspididae) from oceanic coral reefs in the Timor Sea

The threatened grey nurse shark (Carcharias taurus) is reported for the first time from oceanic coral reefs in the Timor Sea. Generally known from temperate and subtropical coastal reef habitats, this species was encountered by Indonesian traditional fishers on oceanic coral reefs in an area of the Australian Exclusive Economic Zone known as the 1974 MoU Box, some 200 km from the Australian mainland. The presence ofC. tauruson these remote tropical reefs bears important management implications, including the species’ protected status in Australian waters and the challenges of regulating catches in areas permitted for traditional Indonesian fishing.

Multiple paternity in captive grey nurse sharks (Carcharias taurus): implications for the captive breeding of this critically endangered species

The grey nurse shark (Carcharius taurus) is listed as threatened throughout much of its global distribution, and as critically endangered in eastern Australia. Captive breeding programs have thus far been largely unsuccessful and little is known of its mating system in this context. Here we carry out a paternity analysis to determine if the mating system in captivity is characterised by multiple mating, and whether poor offspring survival is associated with a particular male. Tissue samples from grey nurse sharks were collected from three potential sires, the two dams and nine pups housed at Manly SEA LIFE Sanctuary in eastern Australia. Each individual was genotyped at seven microsatellite markers and three cases of multiple paternity were inferred. No paternal link to stillborn (5), or scoliotic (2) pups was indicated. For the first time, we show the natural wild phenomenon of multiple paternity occurring in a captive environment.

Migratory patterns and habitat use of the sand tiger shark (Carcharias taurus) in the western North Atlantic

Globally, population declines for the sand tiger shark (Carcharias taurus) have resulted in calls for informed management of populations, including in the western North Atlantic, where they have been listed as a Species of Concern by NOAA Fisheries. However, information on movements and habitat use, critical for informed management of this sand tiger population, is limited. We investigated horizontal and vertical movements of sand tigers along the US east coast using pop-up archival satellite transmitters, supplemented by acoustic telemetry. Thirteen sand tiger sharks were tagged with satellite and acoustic transmitters in Delaware Bay in late August and early September 2008. Ten of these provided satellite data for horizontal tracks using a Kalman filter. Males left Delaware Bay in autumn and moved south along the continental shelf until reaching waters off North Carolina. Females moved east to waters near the edge of the continental slope. Average depth of males was positively correlated with shark size. All individuals spent at least 95% of their time in waters of 17–23°C. Sand tiger sharks appear most susceptible to fisheries in November and December. Slight expansion of the boundaries and timing of an existing shark-directed bottom longline area closure would likely reduce by-catch of sand tiger sharks and enhance recovery of the stock.

Temporal hooking variability among sharks on south-eastern Australian demersal longlines and implications for their management

An experiment was done to quantify species-specific variation in temporal hooking rates from demersal longlines targeting various carcharhinids off south eastern Australia, with a view to reducing the incidental catches of protected species, including the scalloped hammerhead Sphyrna lewini, great hammerhead Sphyrna mokarran and grey nurse Carcharias taurus. The longline comprised a 9600 m mainline, separated into four sections (termed lines) each with 120 gangions (20 m apart) rigged with hook timers and 16/0 circle hooks baited with either sea mullet Mugil cephalus or eastern Australian salmon Arripis trutta. The mainline was deployed on each of 17 nights (between 19:30 and 23:30 h), with two lines retrieved after 7 and 14 h respectively. From a total of 8160 hooks, 246 timers were activated without hooking fish. Twenty-two species comprising 684 individuals were caught, including 52 S. lewini, 12 C. taurus, 11 S. mokarran and 1 loggerhead turtle Caretta caretta. Several environmental factors, including water temperature, moon phase and depth had mostly homogeneous, positive effects on catches. The only identified variables that might be used to considerably reduce the catches of Sphyrna were soak time and/or diurnal gear retrieval, with most individuals hooked during daylight. Simply mandating shorter deployments and within nocturnal retrieval might limit exploitation, especially among juveniles (<150cm total length). For the studied fishery to approach sustainability, future research is required to investigate other gear modifications for improving size and species selectivity, and/or operational procedures for mitigating discard and escape mortalities.

A sand tiger shark–dominated fauna from the Eocene Arctic greenhouse

ABSTRACTWe describe a new shark fauna from Canada's westernmost Arctic island, Banks Island, Northwest Territories, based upon thousands of shark teeth recovered from lower–middle Eocene sediments of the Cyclic Member (Eureka Sound Formation) on northern Banks Island, Northwest Territories (∼74°N latitude). Based upon palynology, the sediments preserving the shark teeth are late early to middle Eocene in age and likely span the Early Eocene Climatic Optimum (EECO). The low-diversity faunal assemblage is dominated by the sand tiger sharks Striatolamia and Carcharias, but also includes relatively rare teeth of the carcharhinid Physogaleus (extinct relative of sharpnose and tiger sharks) and very rare teeth of the odontaspidid Odontaspis winkleri. We also report the occurrence of the ray Myliobatis. Based upon analogy with extant Carcharias taurus and Myliobatis, the presence of Carcharias and Myliobatis on northern Banks Island corroborates the relatively warm sea surface temperatures estimated by others for the Eocene Arctic Ocean. We hypothesize that the low diversity of the Banks Island shark fauna, in comparison with other early Eocene brackish, shallow-marine chondrichthyan assemblages such as the Abbey Wood (U.K.) fauna, is probably due to environmental factors, including reduced salinity.

Scuba diving tourism with critically endangered grey nurse sharks (Carcharias taurus) off eastern Australia: Tourist demographics, shark behaviour and diver compliance

Guidelines and a national code of conduct were implemented to manage scuba diving tourism with the critically endangered grey nurse shark (Carcharias taurus) along the Australian east coast. The demographics of diving tourists, swimming behaviour of grey nurse sharks at various life-history stages and compliance of divers to the guidelines/code of conduct were simultaneously assessed during diver–shark interactions at four sites from March 2011 to February 2012. Milling was the most frequent swimming behaviour observed and no significant changes occurred with the number of divers or distance to sharks. Divers exhibited 100% compliance with all guidelines investigated. Satisfactory compliance may have been attributable to guideline clarity, the ease of establishing diver–shark interactions, stakeholder involvement in management processes and diver perceptions of sharks. Similar sampling of group and individual shark behaviour should be done to further enhance the understanding of the beneficial and adverse impacts of this marine wildlife tourism sector.

Impacts of recreational fishing in Australia: historical declines, self-regulation and evidence of an early warning system

SUMMARYOverfishing is a mounting threat to marine ecosystems and food security worldwide. Recreational fisheries are poorly understood and pose governance challenges due to the scarcity of monitoring data. The impact of recreational spearfishing on eastern blue groper (Achoerodus viridis) and grey nurse shark (Carcharias taurus) in Australia was analysed by assessing a chronology of spearfishing publications for historical, ecological and social data. Reported captures of blue groper declined by 90% from 1952–1967. Grey nurse shark captures also declined. Interestingly, early warnings of declines for both species emerged from the spearfishing community 17 and 19 years, respectively, before protection. While recreational fishers may have serious impacts on vulnerable fish species, they could also play a vital role in conservation and advocacy. This highlights the importance of reciprocal communication between fishers, scientists and governments for managing and detecting declines in vulnerable species.

Ecological importance of sharks and rays in a structural foodweb analysis in southern Brazil

AbstractUnderstanding the trophic interactions and the position of species within a foodweb is crucial if we want to understand the dynamics of marine communities and the impact individual components of the community have on trophic network compartments. Recent studies have indicated sharks and rays are important elements within foodwebs. In this study, we evaluated the ecological importance of sharks and rays in a subtropical ecosystem off the coast of southern Brazil by using topological analyses. We tested the hypotheses that some elasmobranchs can be considered key elements within the foodweb, and that large predators have topological importance (act as keystones), so that, when large predators are excluded, mesopredator elasmobranchs occupy higher topological positions. Our results indicate that Galeocerdo cuvier, Carcharhinus obscurus, Carcharias taurus, Sphyrna lewini and S. zygaena are species with large ecological function values and may exert a powerful influence over lower levels. These issues need to be considered by conservation and fishery management groups since it appears that ecosystem integrity may be compromised by reductions in the populations of large predators. Carcharhinus obscurus, S. zygaena and Zapteryx brevirostris were found to be the elasmobranchs with largest values of centrality, and can, therefore, be considered key elements in the topological structure.

Movement patterns of juvenile sand tigers (Carcharias taurus) along the east coast of the USA

To date, movement patterns of juvenile sand tigers (Carcharias taurus) along the east coast of the USA have been loosely defined. Given the magnitude of the purported decline in the sand tiger population in the western North Atlantic (WNA), characterization of the species’ movement patterns throughout this broad area is essential for the effective management and recovery of this population. Using passive acoustic telemetry, pop-up satellite archival transmitting tags, and conventional fishery-dependent tag/recapture data, seasonal movements of juvenile sand tigers (ages 0–2 years; <125 cm fork length) were monitored between Maine and Florida along the US east coast from 2007 to 2013. Collectively, tag data indicated that juvenile sand tigers undergo extensive seasonal coastal migrations moving between summer (June–October) habitat (Maine to Delaware Bay) and winter (December–April) habitat (Cape Hatteras to central Florida) during the spring (April–June) and fall/early winter (October–December). Juvenile sand tigers occurred in a wide range of temperatures (9.8–26.9 °C) throughout the year, but spent the majority of their time in water from 12 to 20 °C. Given the extensive movements and continuous utilization of relatively shallow (<80 m) nearshore waters exhibited by these relatively small individuals throughout their first years of life, it is imperative that precautions be taken to limit negative effects of anthropogenic interactions on this species (i.e., fisheries bycatch, coastal degradation) in an effort to rebuild and sustain the WNA population.

Amino acid 15N trophic enrichment factors of four large carnivorous fishes

Ecosystem-based fisheries management strategies require knowledge of trophic relationships. Trophic position (TP) estimates from compound specific nitrogen isotopic analysis of amino acids (AA-CSIA) show promise as the method can disentangle confounding factors associated with changing δ15N values at the base of the food web, but it has yet to be tested in many organisms. This novel technique requires two empirically determined biological parameters: 1) β, the difference in δ15N values between glutamic acid (glu) and phenylalanine (phe) in primary producers and 2) trophic enrichment factor (TEF), the 15N enrichment of glu and phe at each trophic step. Values of β (3.4‰) and TEF (7.6‰) have been suggested for animals in aquatic environments; however recent observations indicate that TEF values may be variable, particularly among elasmobranchs where urea retention may alter nitrogen isotope fractionation between glu and phe. To test these uncertainties, we determined TEF values for three species of sharks, sand tiger (Carcharias taurus), lemon (Negaprion brevirostris), and leopard sharks (Triakis semifasciata), and one teleost species, opakapaka (Pristipomoides filamentosus) grown on controlled and well characterized diets for durations ranging from three (T. semifasciata) to over five years (P. filamentosus). TEF values for both elasmobranchs and opakapaka were ~2‰, significantly lower than TEFs previously reported. These results do not support the hypothesis that urea retention lowers 15N trophic enrichment between glu and phe in elasmobranchs. Rather, isotopic enrichment factors may be primarily driven by differences in dietary protein quality, leading to distinct TEFs for herbivores (~7.6‰) and carnivores (<7.6‰). We propose a method to calculate TP which integrates different TEF values for herbivores and carnivores.

The complete mitochondrial genome of the sand tiger shark, Carcharias taurus (Chondrichthyes, Odontaspididae)

The complete mitochondrial genome of the sand tiger shark consists of 16,773 bp and including 13 protein-coding genes, 2 ribosomal RNA, 22 transfer RNA genes, 1 replication origin region and 1 control region. The mitochondrial gene arrangement of the sand tiger shark is the same as the one observed in most vertebrates. Base composition of the genome is A (31.8%), T (28.7%), C (26.3%) and G (13.2%).

Effect of sample preparation techniques for carbon and nitrogen stable isotope analysis of hydroxyapatite structures in the form of elasmobranch vertebral centra

Bulk stable isotope analysis (SIA) provides an important tool for the study of animal ecology. Elasmobranch vertebral centra can be serially sampled to obtain an isotopic history of an individual over ontogeny. The measured total δ(13)C value, however, may be misinterpreted due to the inclusion of the (13)C-rich inorganic portion. Hydrochloric acid (HCl) is commonly used to remove the inorganic portion of hydroxyapatite structures before undertaking SIA, but more recently ethylenediaminetetraacetic acid (EDTA) has been recommended for elasmobranch vertebrae. These acid treatments may introduce uncertainty on measured δ(13)C and δ(15)N values above instrument precision and the effect of small sample size remains untested for elasmobranch vertebrae. Using a non-dilution program on an isotope ratio mass spectrometer the minimum sample weight of vertebrae required to obtain accurate isotopic values was determined for three shark species: white (Carcharodon carcharias), tiger (Galeocerdo cuvier), and sand tiger (Carcharias taurus). To examine if acid treatment completely removes the inorganic component of the vertebrae or whether the technique introduces its own uncertainty on measured δ(13)C and δ(15)N values, vertebrae samples were analyzed untreated and following EDTA treatment. The minimum sample weight required for accurate stable isotope values and the percentage sample yield following EDTA treatment varied within and among species. After EDTA treatment, white shark vertebrae were all enriched in (13)C and depleted in (15) N, tiger shark vertebrae showed both enrichment and depletion of (13)C and (15)N, and sand tiger shark vertebrae were all depleted in (13)C and (15)N. EDTA treatment of elasmobranch vertebrae produces unpredictable effects (i.e. non-linear and non-correctable) among species in both the percentage sample yield and the measured δ(13)C and δ(15)N values. Prior to initiating a large-scale study, we strongly recommend investigating (i) the minimum weight of vertebral material required to obtain consistent isotopic values and (ii) the effects of EDTA treatment, specific to the study species and the isotope ratio mass spectrometer employed.

Scuba diving with the grey nurse shark (Carcharias taurus): an application of the theory of planned behaviour to identify divers beliefs

Abstract Scuba diving with the critically endangered grey nurse shark (Carcharias taurus) is a popular attraction for divers on the east coast of Australia. As the popularity of shark diving develops globally, research is required to evaluate how diving with sharks affects the behaviour and ecology of the species. Understanding participant's behaviour when diving with C. taurus can provide valuable information for researchers and policy makers trying to conserve this species. An elicitation procedure based on the theory of planned behaviour was applied to determine divers’ beliefs pertinent to approaching C. taurus when scuba diving at two sites on Australia's east coast. A content analysis of responses revealed preliminary insights into the salient beliefs of divers. This initial step is an essential foundation for subsequent phases of research and communication aimed at improving shark and diver interactions and experiences. Copyright © 2014 John Wiley &amp; Sons, Ltd.