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Integrated analysis of the vertical and horizontal movements of epipelagic fishes requires high-resolution data from tags that have been attached to animals for long periods. The recovery of a SPLASH tag deployed on a whale shark Rhincodon typus for 3 mo enabled access to archival data of horizontal and vertical movements of the shark that travelled 5380 km from Christmas Island to the Banda Sea. We examined water temperature and bathymetry to compare movements of the shark with key oceanographic features. Over 89 d, we identified 1931 dives and grouped these into 5 broad categories depending on dive shape. To investigate the potential for these dives to reflect behavioural thermoregulation, we used boosted regression trees to model the relationship between pre- and post-dive surface durations and dive characteristics. The movements of the shark were correlated with water temperatures, with the animal following frontal systems while remaining in a sea surface temperature (SST) range of 24-29°C. Across the continental shelf off north-western Australia, the shark mostly remained near the seafloor, likely avoiding very warm SSTs and strong currents at the surface. U- (foraging) and V- (searching) shaped dives accounted for ~78% of dives. Foraging dives during the day descended to 200-500 m and were preceded and followed by extended periods at the surface, whereas at night, the shark rarely dived below 200 m, likely foraging near the thermocline. Our results show how water temperatures influence the movement of this whale shark, with ‘basking’ at the surface during the day likely to gather environmental heat for thermoregulation, aiding to maintain body temperatures.

Declines in abundance of sea snakes have been observed on reefs throughout the Indo-Pacific, although the reasons are unknown. To date, surveys have occurred on shallow reefs, despite sea snakes occurring over a large depth range. It is not known if populations of sea snakes in deep habitats have undergone similar declines. To address this, we analysed deep-water video data from a historical hotspot of sea snake diversity, Ashmore Reef, in 2004, 2016, and 2021. We collected 288 hours of video using baited remote underwater videos and a remotely operated vehicle at depths between 13 and 112 m. We observed 80 individuals of seven species with Aipysurus laevis (n = 30), Hydrophis peronii (n = 8), and H. ocellatus (n = 6) being the most abundant. Five of the species (A. duboisii, A. apraefrontalis, H. ocellatus, H. kingii, and Emydocephalus orarius) had not been reported in shallow waters for a decade prior to our study. We found no evidence of a decline in sea snakes across years in deep-water surveys, although abundances were lower than those in early shallow-water surveys. A comparison of BRUVS data from 2004 and 2016 was consistent with the hypothesis that predation by sharks may have contributed to the loss of sea snakes in shallow habitats. Our study highlights the use of underwater video to collect information on sea snakes in the mesophotic zone and also suggests that future monitoring should include these depths in order to capture a more complete representation of habitats occupied.

Monitoring the demographics and movement patterns of mobile marine species underpins appropriate management and conservation strategies. Photographic identification of whale sharks Rhincodon typus based on individual variations in spot patterns is a widely used technique for monitoring of populations, but relies on the untested assumptions that these variations in spot patterns are unique to each shark and can be reliably detected using photo-matching software. This study validated the accuracy of photo-identification technique by manually determining the number of photo-identified individuals showing mismatched genetic profiles created for the individuals using 12 microsatellite markers. Results from 154 photographic and genetic identifications of whale sharks were 100% concordant, showing the uniqueness of spot patterns to each shark and high accuracy of the photo-identification technique. Based on these techniques, we observed an annual resighting rate of approximately 10% at Ningaloo Reef, Western Australia, between 2016 and 2018, showing evidence that variations in spot patterns did not change over a time scale of years. Our study shows that the photographic identification technique provides a reliable means to recognise individuals and monitor whale sharks through time.

Predatory fishes are a major component of many tropical fisheries, although little is known about their diet and trophic structure, which can hinder effective management. We used stable isotopes δ15N and δ13C in conjunction with dietary prey items of five fishes (Lutjanus sebae, Lethrinus punctulatus, Epinephelus areolatus, Epinephelus multinotatus, and Plectropomus maculatus) to describe the diet and trophic structure across this assemblage. A total of 153 isotope and 87 stomach content samples were collected at two locations that were ≈30 km apart, over two sampling trips, separated by three months. There was clear separation of species’ mean δ15N and δ13C values in isotopic space; the highest mean δ15N was exhibited by E. multinotatus (13.50 ± 0.11 SE) and the lowest was L. punctulatus (11.05 ± 0.13). These two species had the lowest overlap of isotopic niche space, whereas the highest overlap occurred between L. sebae and P. maculatus. δ15N increased with fish body size for all species. However, body size was not significantly related to δ13C values for any species. There was a notable shift in both δ15N and δ13C between sampling trips, with δ13C being more depleted in the second trip. There was also a difference in δ13C between locations for all species, suggesting localised foraging. A multiple tissue comparison for L. sebae indicated positive relationships for both δ15N and δ13C between dorsal fin and muscle tissue. Mean δ15N values were the same for both fin (12.1 ± 0.10 SE) and muscle tissue (12.1 ± 0.09 SE), although δ13C was more enriched in fin (-15.6 ± 0.14 SE) compared to muscle tissue (-17.3 ± 0.11 SE). The most common dietary items across species were teleosts and crustaceans, which was consistent with isotope data indicating a reliance on a demersal food web (δ13C values ranging from -18 to -15‰). The results from our study indicate a dynamic spatio-temporal trophic structure and diet for commercially important demersal species and highlight the benefits of a multi-facetted sampling approach.

Identification of latitudinal trends in growth and maximum ages provides important insights into the vulnerability of coral reef fishes to human exploitation. Here, we sampled three species of unharvested tropical snappers from 4 locations along the tropical Western Australian coast and from the Chagos Archipelago in the central Indian Ocean. Interpretation of sectioned sagittal otoliths identified 2 species as the longest-lived tropical reef-associated fishes recorded to date, with a combined eleven specimens aged > 60 yrs, a single Lutjanus bohar aged 79 yrs and a single Macolor macularis aged 81 yrs (both from Rowley Shoals, Western Australia). These maximum ages are two decades greater than previous estimates of maximum age for reef fishes. Lifetimes of such long durations confirm the low rates of natural mortality for these species, their associated low production potential, and the need for effective systems of governance to enable sustainable harvests across the distributions of these species.

Individual growth rate is one of the key traits that determine the productivity of populations. Chronological approaches that relate time series of growth and climate information present the opportunity to identify important climatic drivers of demography and thereby understand the likely impact of climate change. We constructed otolith chronologies (a proxy for somatic growth) to examine synchrony of growth patterns within and between two mesopredatory fishes (Lutjanus bohar and L. gibbus) in the remote Chagos Archipelago, Indian Ocean. We then used mixed-model and pathway analysis to relate growth responses to a suite of climatic and environmental factors to determine the extent to which variation in inter-annual growth could be predicted at individual and population levels. Our models explained up to half the variance associated with annual growth at the level of populations. Significant environmental drivers of growth differed between species, as did the spatial scale of these drivers: L. gibbus exhibited a strong relationship with regional ocean temperature, whereas growth of L. bohar was correlated with the Pacific Decadal Oscillation, suggesting influential teleconnections between ocean basins as an underlying predictor of productivity of fish populations. Our results demonstrate that (1) synchronous growth stemming from relationships with climate factors may be suppressed at very low latitudes; (2) closely related species may respond to very different environmental stimuli; and (3) within the same environment, the scale of influential drivers may be local in nature or reflect oceanographic processes stretching across entire ocean basins. We demonstrate that biochronological approaches are effective tools for reconstructing relationships between climate variability and fish growth even in tropical regions where seasonality is low, and these methods can be valuable for forecasting population-level responses to projected climate change.

Major aggregations of nesting green turtles (Chelonia mydas) occur in the northern Red Sea, although little is known about the reproductive ecology of this endangered species in the region. To address this issue, we satellite-tracked 30 female green turtles to document their movements and to identify factors driving habitat use at two major rookeries in the Red Sea, Jazirat Mashabah (Mashabah Island) and Ras Al Baridi in Saudi Arabia. Between successive nesting events, turtles displayed high fidelity to nesting beaches and adjacent in-water habitats (inter-nesting habitats). Using generalized linear mixed models, we estimated the mean probability of nesting per beach emergence (nesting success rate) to be 0.628, and the mean duration between a successful nesting event and the successive emergence onto the beach (re-nesting interval) to be 10.8 days at each site. The nesting success rate was relatively high (>0.8) when the preceding daytime land surface temperature (LST) was lower than 37°C but decreased with elevated daytime LST (47°C). Re-nesting interval was longer at lower water temperatures and towards the end of the nesting season of individuals. Our study improves the robustness of abundance estimates from census data (e.g., track counts) and shows that the protection of nesting and inter-nesting habitats during a breeding season would be an effective conservation strategy for the species. We discuss how global warming could increase energy expenditure due to lowered nesting success, ultimately compromising the reproductive fitness of these populations.

Whale sharks off the western coast of India have suffered high levels of fishing pressure in the past, and today continue to be caught in small-scale fisheries as by-catch. Additionally, coastlines in this region host very large and growing human populations that are undergoing rapid development. This exacerbates ongoing anthropogenic threats to this species such as pollution, habitat loss, and ship traffic. For these reasons, there is an urgent need for data on movement patterns of whale sharks in this region of the Indian Ocean. Here, we address this issue by providing the first data on the horizontal movements of whale sharks tagged in the northern Arabian Sea off the western coast of the Indian state of Gujarat. From 2011 to 2017, eight individuals, ranging from 5.4 to 8 m were tagged and monitored using satellite telemetry. Tag retention varied from 1 to 137 days, with the sharks traveling distances of 34 – ∼2,230 km. Six of the eight individuals remained close to their tagging locations, although two sharks displayed wide ranging movements into the Arabian Sea, following frontal zones between water masses of different sea surface temperatures. We explore the relationship between the movement patterns of these whale sharks and the physical and biological processes of the region.

Large epipelagic fishes (> 30 kg maximum size) are known to display a variety of patterns of vertical movement. Although advances in the affordability and sophistication of electronic tags now allows researchers to routinely document these patterns, there is no standardised approach to classify these behaviours and investigate their physical and biological drivers. This paper reviews the existing knowledge of the vertical movements of large, epipelagic fishes and the evidence for the underlying factors that structure this behaviour. The review focuses on behaviours occurring at a range of temporal scales, from seconds to years. We propose that patterns of vertical movement in gill-breathing animals of the epipelagic are best characterised by the need to move continuously in a three-dimensional environment while optimising food encounter and energy expenditure, avoiding predators, searching for mates and remaining within the limits imposed by the physical environment on their physiology (notably water temperature and oxygen). Modern biologging technologies that record both the internal (body temperature, heart rate) and external physical environment coupled with direct recording of behaviour from tri-axial sensors and animal-borne cameras offer a new approach to the analysis of drivers of vertical movement. Ultimately, this can provide insights into the evolution of the behaviour and morphology of these animals.

Shark-diving tourism is a fast-growing industry that provides socio-economic benefits to local communities. This study estimated the economic contribution of the shark-diving tourism in the Maldives by using surveys with dive tourists and dive operators. Direct business revenue from shark divers was estimated to be US$14.4 million. Revenues to local businesses associated with travel expenses of shark divers were estimated to be US$51.4 million. Further economic benefits from shark-diving occurred in form of annual business tax revenues of US$7.2 million and annual salaries to employees working in the diving industry of US$4.1 million. These values were compared with the business revenues from shark-diving in the Maldives in 1992 to assess how the shark-diving industry has changed over time. The results of this study indicate that the business revenues of this industry have almost doubled (when inflation adjusted) over the last 24 years confirming its economic growth and importance for the Maldives. Effective management of shark dive operations is crucial for maintaining the value and sustainability of this tourism industry to improve ongoing conservation efforts for shark populations.

Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fish abundance, at least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of green turtle clutches (Chelonia mydas) is ~ 20,500 and increasing and the number of seabirds is ~ 1 million. Animal tracking studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fishes, elasmobranchs and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats to this MPA have been identified, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fishing activity, which considerably impact both reef and pelagic fishes.

Age and growth data are central to management or conservation strategies for any species. Circumstantial evidence suggests that male whale sharks (Rhincodon typus) grow to asymptotic sizes much smaller than those predicted by age and growth studies and consequently, there may be sex-specific size and growth patterns in the species. We tested this hypothesis by using stereo-video and photo-identification studies to estimate the growth rates of 54 whale sharks that were resighted over a period of up to a decade at Ningaloo Reef. We found that male growth patterns were consistent with an average asymptotic total length (TL) of approximately 8–9 m, a size similar to direct observations of size at maturity at aggregation sites world-wide and much smaller than the sizes predicted by earlier modeling studies. Females were predicted to grow to an average asymptotic length of around 14.5 m. Males had growth coefficients of K = 0.088 year–1, whereas limited resighting data suggested a growth coefficient of K = 0.035 year–1 for females. Other data including re-sightings of an individual male over two decades, records of sex-specific maximum sizes of individuals captured in fisheries and data from juveniles growing in aquaria were also consistent with the suggestion of sex-specific growth profiles for the species. We argue that selection for sex-specific growth patterns could explain many of the otherwise enigmatic patterns in the ecology of this species including the tendency of the species to form aggregations of juvenile males in coastal waters.

Publisher's version (útgefin grein), Conservation and management strategies for endangered and threatened species require accurate estimates of demographic parameters such as age and growth. The whale shark, Rhincodon typus, is the largest fish in the world and is highly valued in the eco-tourism sector. Despite conservation concerns and advances in our understanding of their life history, basic demographic parameters for growth, longevity and mortality are of questionable accuracy; previous growth studies could not agree whether the vertebral growth bands were formed annually or biannually. Here, we provide the first validation of the annual formation of growth bands within the vertebrae of the whale shark using bomb radiocarbon assays. Ages of up to 50 years were estimated from sectioned vertebrae of sharks collected in Taiwan and Pakistan. There was no cessation of the formation of growth bands in the vertebrae of older sharks and our study provides the oldest observed longevity for this species. Initial estimates of growth (k = 0.01–0.12) and natural mortality rates (M = 0.09–0.14) are consistent with those expected of long-lived sharks, which highlights their sensitivity to fishing pressure and conservation concerns., This work was supported by the Fisheries and Oceans Canada, US National Science Foundation Grant OCE-9985884, and the University of Iceland. Travel funding was provided by the Australian Institute of Marine Science.

International audience; Coastal populations of maritime countries in eastern Africa rely on fish as a primary source of protein, but baseline information on the abundance of fish communities on these coastlines is often lacking. We used baited remote underwater video stations to compare the abundance and diversity of reef fishes targeted by fishing at two sites in southern Mozambique, one at Lighthouse Reef within the Bazaruto Archipelago National Park and the other to the south at San Sebastian Reef on the San Sebastian Peninsula. Fish that are known targets of fisheries (mostly small-scale and artisanal) had an abundance that was almost three-times greater at San Sebastian Reef (80.22 ind. h–1 [SE 18.00]) than at Lighthouse Reef (29.70 ind. h–1 [SE 8.91]). Similarly, there was greater mean species richness at San Sebastian Reef (38.74 species h–1 [SE 2.79]) than at Lighthouse Reef (25.37 species h–1 [SE 3.66]). The main drivers of targeted fish abundance were habitat and depth, with shallow (

This study estimated the economic value of the shark-diving industry in Semporna, the most popular diving destination of Malaysia, by surveying the expenditures of diving tourists and dive operators through the region. A willingness-to-pay survey was also used to estimate the potential of the industry as a financing mechanism for enforcement and management of a hypothetical Marine Protected Area (MPA) to conserve shark populations. The study showed that in 2012, shark-diving tourism provided direct revenues in excess of USD 9.8 million to the Semporna region. These economic benefits had a flow-on effect, generating more than USD 2 million in direct taxes to the government and USD 1.4 million in salaries to the community. A contingent valuation analysis indicated that implementation of a fee paid by divers could generate over USD 2 million for management and enforcement of the MPA each year. These findings suggest that shark diving is an important contributor to the economy of the Semporna region that could be used as a mechanism to assist financial resourcing for management and conservation strategies.

Special thanks to the staff of Mackerel Island, Dennis Stanley and Dr Suzanne Long for their assistance in field experiments and to Dr Vinay Udyawer for providing R code for track animations. The Department of Biodiversity, Conservation and Attractions (formerly Department of Parks and Wildlife), the Australian Institute of Marine Science and the University of Western Australia provided financial support. All procedures were approved by the University of Western Australia Animal Ethics Committee (RA/3/100/1423) and Department of Biodiversity, Conservation and Attractions licenses SF010696.

We thank the Western Australian Departments of Fisheries, Parks and Wildlife (DPaW), the Commonwealth Department of Sustainability, Environment, Water, Population and Communities for arranging permits to conduct research at the Scott Reefs and the Rowley Shoals. We acknowledge the crew on board the RV 'Solander,' Kim Brooks, Paul Tinkler and numerous volunteers for aid in the field. Thanks also to Paddy Ryan who provided images for the figures. Special thanks to Sarah Hirth, Gammon Koval, Rachel Skubel and Marcelo Costa Lopez for help with some figures. This research was funded in part by the Australian Institute of Marine Science, an International Postgraduate Research Scholarship to S.C.B., the Save our Seas Foundation and the University of Western Australia, Perth, under UWA Ethics Approvals: RA3/100/1279, RA3/100/1172. We thank Ashley Frisch and several reviewers who provided valuable comments that improved our manuscript.

Many marine fish populations have declined due to the individual or cumulative impacts of increasing water temperatures, ocean acidification, overfishing and other human-induced impacts such as land run-off, dredging and habitat alteration. Some solutions may be offered by ecosystem-based fisheries and conservation management. However, understanding their effectiveness relies on the availability of good quality data on the size distributions and abundance of fish populations and assemblages, collected at appropriate temporal and spatial scales. Since the early 2000s, baited remote underwater video systems (BRUVs) have become a popular tool for collecting data on fish assemblages across a range of depths and habitats. In Australia, this technique has been adopted by many different agencies and institutions, creating a unique opportunity to compile a continental-scale synthesis of fish data using a standardised sampling technique. Key Australian researchers and managers were invited to contribute to a synthesis workshop on baited underwater video in Albany, Western Australia between the 4th and 8th of February 2018. Data from 19,939 BRUVs deployments, collected between 2000 and 2017 around Australia, were compiled using GlobalArchive (globalarchive.org). The workshop identified and prioritised several key research themes that would contribute to the conservation and sustainable management of focal species and broad assemblages. Our goal is to describe where and when the data were collected, the type of equipment used and how the imagery was analysed. We also discuss the types of questions that can be addressed by analysing these standardised datasets and the potential benefits to conservation and fisheries management.

Mutualisms are pivotal in shaping ecological communities. Iconic images of cleaner fish entering the mouths of predatory fish clients to remove ectoparasites epitomize their mutual benefit. Experimental manipulations of cleaner wrasse reveal declines in fish size and growth, and population abundance and diversity of client fishes in the absence of cleaner wrasse. Fishes grow more slowly and are less abundant and diverse on reefs without cleaner wrasse, both for larger species that are regularly cleaned and have high ectoparasite loads (“attractive species”), and for those smaller species that are rarely cleaned and are rarely infested with parasites (“unattractive species”). We therefore considered whether these previously observed declines in individual and population parameters on reefs without cleaners were related to increased ectoparasite infestation using an attractive species (Hemigymnus melapterus, Labridae) and an unattractive species (Pomacentrus amboinensis, Pomacentridae). Traps with these fish as a form of bait were deployed to sample blood-sucking gnathiid ectoparasites (Gnathiidae: Isopoda) on reefs from which cleaners (Labroides dimidiatus, Labridae) have been removed for 13 yr. Cleaner fish could not enter traps to access the clients/hosts, but gnathiids could enter the traps to infest hosts; thus, this method sampled the indirect effect of cleaners on gnathiid infestation of fish. Infestation was higher on reefs without cleaners than on those with them. The effect was only detected during the daytime when cleaners are active and only on the attractive species (H. melapterus). Thus, cleaner presence indirectly reduced fish exposure to parasites in a species that is highly susceptible to parasites, but not in one that is rarely infested with parasites. This suggests that cleaner presence indirectly reduces exposure of a common fish species to harmful parasites, which may explain some observed benefits in fishes at this location.

Shark-diving is part of a rapidly growing industry focused on marine wildlife tourism. Our study aimed to provide an estimate of the economic value of shark-diving tourism across Australia by comprehensively surveying the whale shark (Rhincodon typus), white shark (Carcharodon carcharias), grey nurse shark (Carcharias taurus), and reef shark (mostly Carcharhinus amblyrhynchos and Triaenodon obesus) diving industries using a standardised approach. A socio-economic survey targeted tourist divers between March 2013 and June 2014 and collected information on expenditures related to diving, accommodation, transport, living costs, and other related activities during divers’ trips. A total of 711 tourist surveys were completed across the four industries, with the total annual direct expenditure by shark divers in Australia estimated conservatively at $25.5 M. Additional expenditure provided by the white-shark and whale-shark-diving industries totalled $8.1 and $12.5 M for the Port Lincoln and Ningaloo Reef regions respectively. International tourists diving with white sharks also expended another $0.9 M in airfares and other activities while in Australia. These additional revenues show that the economic value of this type of tourism do not flow solely to the industry, but are also spread across the region where it is hosted. This highlights the need to ensure a sustainable dive-tourism industry through adequate management of both shark-diver interactions and biological management of the species on which it is based. Our study also provides standardised estimates which allow for future comparison of the scale of other wildlife tourism industries (not limited to sharks) within or among countries.

We thank the University of Western Australia (UWA), Perth, which partly funded this research via an International Postgraduate Research Scholarship and the Australian Institute of Marine Science. We also thank the Department of Fisheries, the Department of Parks and Wildlife (DPaW) and the Department of Sustainability, Environment, Water, Population and Communities for arranging permits to conduct research at the Scott Reefs and the Rowley Shoals. Thank you also to the crew on board the RV 'Solander'. This research was permitted under UWA Ethics Approvals: RA3/100/1279, RA3/100/1172.

Chemoreception cues potentially influence intraspecific interactions of cephalopods, including mate choice. However, at present there is limited empirical evidence demonstrating whether cephalopods can use olfaction to identify the sex or identity of conspecifics. This study examined the responses of the southern blueringed octopus, Hapalochlaena maculosa (Hoyle, 1883), to conspecific odours during controlled laboratory trials. The ventilation rates in aquaria of 25 wild-sourced animals were measured during four treatments: baseline, sea water, sea water containing male conspecific odour and sea water containing female conspecific odour. When used as 'receivers' in trials, female H. maculosa significantly increased their ventilation rates in response to male odours, but not to female odours. However, female response decreased significantly with the receiver's size during female-odour treatments. The ventilation rates of male H. maculosa were statistically similar in all treatments. However, their ventilation rates showed a significant progressive increase over the observation period during male and female-odour treatments. Eighteen of these animals (nine females and nine males) were used in focal-animal trials 1 week after odour-cue experiments. Of these individuals, females were significantly more receptive to copulation attempts, and spent significantly more time per day in copulation, with males whose odours had elicited a weaker ventilation response in prior trials. These results suggest that female H. maculosa can use chemosensory cues to discriminate the sex, and possibly identity, of conspecifics and that this information might influence their mate choice. However, the mechanisms underlying these responses and subsequent copulatory access to females by males remain unknown.

Biochronologies provide important insights into the growth responses of fishes to past variability in physical and biological environments and, in so doing, allow modelling of likely responses to climate change in the future. We examined spatial variability in the key drivers of inter-annual growth patterns of a widespread, tropical snapper, Lutjanus bohar, at similar tropical latitudes on the north-western and north-eastern coasts of the continent of Australia. For this study, we developed biochronologies from otoliths that provided proxies of somatic growth and these were analysed using mixed-effects models to examine the historical drivers of growth. Our analyses demonstrated that growth patterns of fish were driven by different climatic and biological factors in each region, including Pacific Ocean climate indices, regional sea level and the size structure of the fish community. Our results showed that the local oceanographic and biological context of reef systems strongly influenced the growth of L. bohar and that a single age-related growth trend cannot be assumed for separate populations of this species that are likely to experience different environmental conditions. Generalised predictions about the growth response of fishes to climate change will thus require adequate characterisation of the spatial variability in growth determinants likely to be found throughout the range of species that have cosmopolitan distributions.

In order to examine the foraging behavior of whale sharks at Ningaloo Reef in Western Australia, stable isotope analysis of the dermis was used to estimate 13C and 15N values. These were compared to isotope values obtained from likely species of local prey. Ontogenetic and sex-related variations in the isotopic composition of dermis were also examined. The 13C values of zooplankton and nektonic taxa at Ningaloo ranged from -18.9‰ to -16.5‰ reflecting the different carbon sources entering the food web (from a pelagic to a more inshore and benthic productivity). The isotopic composition suggests that whale sharks had greater reliance on pelagic primary and secondary productivity over a period of ~3 years. Whale shark isospace matched some of the potential prey at Ningaloo Reef including krill, zooplankton and polychaetes. Consistency on 13C values indicated regional foraging ranges across the Ningaloo Reef area and the western Australian coast. More variability in 15N values showed, however, the different patterns of foraging among whale sharks. There was evidence of enrichment in 15N occurring with increasing size in male and female whale sharks, a pattern that could have been due to changes in growth rate and trophic level with age and/or an ontogenetic shift in feeding grounds. Our study brings new insights into the diet and feeding habits of an important whale shark population over large temporal and spatial scales in the eastern Indian Ocean. Such temporal and spatial information is essential for a better conservation management of this highly migratory and elusive species.

An understanding of the role that large marine predators play in structuring trophic flow and nutrient cycling in marine ecosystems requires knowledge of their fine-scale (m-km) movement behaviours. In this study, biologging tags were used to reveal new insights into the three-dimensional fine-scale movement ecology of tiger sharks (Galeocerdo cuvier) at Ningaloo Reef, Western Australia. Tags deployed on 21 sharks in April-May 2017 for durations of 5-48 hours recorded both physical parameters such as depth and temperature, and, through the use of accelerometers, gyroscopes and compasses, in-situ measurements of animal trajectory and locomotion. Animal-borne-video enabled the validation of behavioural signatures, mapping of habitat, and recording of interactions with prey. Collectively, these data were used to examine the link between vertical (oscillations) and horizontal (tortuosity) movements, and link sensor data to prey interactions recorded by the video. This biologging approach revealed complex movements that would otherwise be invisible within the time-depth records provided by traditional tagging techniques. The rate of horizontal turning was not related to vertical oscillations, suggesting that vertical movements occur independently of searching behaviours in tiger sharks. These animals displayed tortuous movements possibly associated with prey searching for 27% of their tracks, and interactions with prey elicited varied responses including highly tortuous paths and burst movements. Accurate speed measurements and GPS anchor points will considerably enhance the value of magnetometer data in future studies by facilitating more accurate dead-reckoning and geo-referencing of area-restricted search behaviours.

Tracking data have led to evidence-based conservation of marine megafauna, but a disconnect remains between the many 1000s of individual animals that have been tracked and the use of these data in conservation and management actions. Furthermore, the focus of most conservation efforts is within Exclusive Economic Zones despite the ability of these species to move 1000s of kilometers across multiple national jurisdictions. To assist the goal of the United Nations General Assembly’s recent effort to negotiate a global treaty to conserve biodiversity on the high seas, we propose the development of a new frontier in dynamic marine spatial management. We argue that a global approach combining tracked movements of marine megafauna and human activities at-sea, and using existing and emerging technologies (e.g., through new tracking devices and big data approaches) can be applied to deliver near real-time diagnostics on existing risks and threats to mitigate global risks for marine megafauna. With technology developments over the next decade expected to catalyze the potential to survey marine animals and human activities in ever more detail and at global scales, the development of dynamic predictive tools based on near real-time tracking and environmental data will become crucial to address increasing risks. Such global tools for dynamic spatial and temporal management will, however, require extensive synoptic data updates and will be dependent on a shift to a culture of data sharing and open access. We propose a global mechanism to store and make such data available in near real-time, enabling a holistic view of space use by marine megafauna and humans that would significantly accelerate efforts to mitigate impacts and improve conservation and management of marine megafauna., Workshop funding and support granted by ARC Grant No. DE170100841, AIMS, KAUST, and UWA Oceans Institute through a Research Impact Grant. AS was supported by an ARC Grant No. DE170100841 and AIMS. DS was supported by the UK Natural Environment Research Council (NE/R00997X/1) and the Save Our Seas Foundation. NQ was supported by FCT (Portugal). HC was supported by an Australian Government RTP scholarship at UWA.

The expanding use of biologging tags in studies of shark movement provides an opportunity to elucidate the context and drivers of fine-scale movement patterns of these predators. In May 2017, we deployed high-resolution biologging tags on four mature female sandbar sharks Carcharhinus plumbeus at Ningaloo Reef for durations ranging between 13 and 25.5 h. Pressure and tri-axial motion sensors within these tags enabled the calculation of dive geometry, swimming kinematics and path tortuosity at fine spatial scales (m-km) and concurrent validation of these behaviors from video recordings. Sandbar sharks oscillated through the water column at shallow dive angles, with gliding behavior observed in the descent phase for all sharks. Continual V-shaped oscillatory movements were occasionally interspersed by U-shaped dives that predominately occurred around dusk. The bottom phase of these U-shaped dives likely occurred on the seabed, with dead-reckoning revealing a highly tortuous, circling track. By combining these fine-scale behavioral observations with existing ecological knowledge of sandbar habitat and diet, we argue that these U-shaped dives are likely to be a strategy for bentho-pelagic foraging. Comparing the diving geometry of sandbar sharks with those of other shark species reveals common patterns in oscillatory swimming. Collectively, the fine-scale movement patterns of sandbar sharks reported here are consistent with results of previous biologging studies that emphasize the role of cost-efficient foraging in sharks.

Waves are thought to provide an important directional cue for hatchlings of marine turtles to navigate through the nearshore zone and to facilitate dispersal to oceanic waters. As the flatback turtle (Natator depressus) is the only species of marine turtle that lacks an oceanic juvenile stage and remains on the continental shelf throughout the entire life cycle, it is possible that hatchlings of this species do not use wave cues for early dispersal. Here, we used a wave flume to examine the response of flatback turtle hatchlings to waves as a cue for nearshore dispersal. We exposed hatchlings to two types of waves (sea and swell waves) differing in height and period commonly experienced at nesting locations and monitored swimming direction (orientation). Hatchlings oriented towards shorter period (3 s) sea waves with both small (6 cm peak to trough) and large (12 cm peak to trough) wave heights. Orientation of hatchlings to longer period (8 s) swell waves only occurred with large (16 cm peak to trough) and not with small (7 cm peak to trough) wave heights. Acceleration generated by waves was the strongest predictor of directional preference in hatchling bearings. There was a positive relationship between maximum acceleration and directional preference, with hatchling bearings more concentrated (r-value 0.98) towards the oncoming wave direction with waves that produced the highest acceleration (sea waves with largest wave heights). These waves were similar to sea waves generated from onshore winds, which was the most common type of wave we measured at a flatback turtle nesting beach. Our study has confirmed that despite lacking an oceanic development stage, flatback hatchlings, like other species of sea turtles, can detect and respond to wave cues, and that the accelerations generated by waves may be a key characteristic of waves that drives orientation.

We are grateful to people who contributed to field-work, including Captain Terry Maxwell and his crew on board of 'Osso Blu', as well as all the scientific team from the Australian Institute of Marine Science with special mention to Kim Brooks and the WA Department of Parks and Wildlife. We also thank Peter Mansour at CSIRO for his help with lipid and fatty acid analysis and Ella Clausius for her work in identifying zooplankton samples. Janet A. Ley and 3 anonymous reviewers are thanked for their helpful comments that improved the final manuscript. This research was funded by the Save Our Seas Foundation, Winifred Violet Scott Charitable Trust and Holsworth Wild-life Research Endowment Grants.

The authors acknowledge the Save Our Seas Foundation and a private donor for financial support.

Marine protected areas (MPA) are one management tool that can potentially reduce declining shark populations. Protected-area design should be based on detailed movements of target animals; however, such data are lacking for most species. To address this, 25 sharks from three species were tagged with acoustic transmitters and monitored with a network of 103 receivers to determine the use of a protected area at Mangrove Bay, Western Australia. Movements of a subset of 12 individuals ( Carcharhinus melanopterus [ n = 7 ]), C. amblyrhynchos [ n = 2 ], and Negaprion acutidens [ n = 3 ]) were analysed over two years. Residency for all species ranged between 12 and 96%. Carcharhinus amblyrhynchos had C. melanopterus adults that ranged between 0 and 99%. Juvenile sharks had high percentages of position estimates in the MPA (84–99%). Kernel density activity centres for C. melanopterus and C. amblyrhynchos were largely outside the MPA and mean activity space estimates for adults were 12.8 km 2 (±3.12 SE) and 19.6 km 2 (±2.26), respectively. Juveniles had smaller activity spaces: C. melanopterus , 7.2 ±1.33 km 2 ; N. acutidens , 0.6 km 2 (±0.04). Both C. melanopterus and C. amblyrhynchos had peaks in detections during daylight hours (1200 and 0900 h, respectively), whereas N. acutidens had a peak in detections at 0200 h. Long-distance movements were observed for adult C. melanopterus and C. amblyrhynchos , the longest being approximately 275 km. These migrations of C. melanopterus might be related to reproductive behaviours, because they were all observed in adult females during the summer months and provide links between known in-shore aggregation and possible nursery areas. The MPA at Mangrove Bay provided some protection for juvenile and adult reef sharks, although protection is likely greater for juveniles due to their more restricted movements.

The presence of bluestreak cleaner wrasse, Labroides dimidiatus, on coral reefs increases total abundance and biodiversity of reef fishes. The mechanism(s) that cause such shifts in population structure are unclear, but it is possible that young fish preferentially settle into microhabitats where cleaner wrasse are present. As a first step to investigate this possibility, we conducted aquarium experiments to examine whether settlement-stage and young juveniles of ambon damselfish, Pomacentrus amboinensis, selected a microhabitat near a cleaner wrasse (adult or juvenile). Both settlement-stage (0 d post-settlement) and juvenile (~5 weeks post-settlement) fish spent a greater proportion of time in a microhabitat adjacent to L. dimidiatus than in one next to a control fish (a non-cleaner wrasse, Halichoeres melanurus) or one where no fish was present. This suggests that cleaner wrasse may serve as a positive cue during microhabitat selection. We also conducted focal observations of cleaner wrasse and counts of nearby damselfishes (1 m radius) to examine whether newly settled fish obtained direct benefits, in the form of cleaning services, from being near a cleaner wrasse. Although abundant, newly settled recruits (

To demonstrate conservation effects resulting from marine protected areas, many studies rely on spatial comparisons between areas afforded different levels of protection. These spatial comparisons can be confounded if the habitat and reef size are dissimilar and not accounted for in the statistical analysis. Taking into account reef size (obtained from multibeam sonar data) and benthic habitat structure, this research tested the effect of management zonation (No-take Sanctuary Zone = NTSZ; Controlled Pelagic Zone = CPZ) on the population structure (relative abundance and average biomass) of six fish species in the iSimangaliso Wetland Park, South Africa. Furthermore, this study tested the effect of ignoring reef size in spatial comparisons. Our results showed that reef size had a significant positive effect on the relative abundance and average biomass of most, but not all species. When reef size was included in the models, the results showed that two of the six species presented no effect of management zone; two appeared to be directly affected by the permitted (past and present) fishing activity in the CPZ; and the last two species appeared to be affected by the disturbance caused by the diving and/or boating activity in the CPZ. Excluding reef size from the analysis consistently resulted in the predicted relative abundance and average biomass decreasing in the CPZ and increasing in the NTSZ. This effect was most marked in the average biomass data, as the management zone effect changed from negligible to significant for five of the six species. Our results highlight the importance of accounting for the reef size, or area of suitable habitat, when conducting spatial comparisons among species and illustrate the potential impact of the trade-off required to accommodate human needs within protected spaces.

The coastline of northern Australia may be a refuge for elasmobranchs threatened or extirpated from much of their former ranges across South-East Asia. In this study, we used baited remote underwater video stations to survey the abundance, size and assemblage of elasmobranchs in the Cobourg Marine Park in northern Australia. Two sites were sampled inside the park and one site was sampled outside the park, covering two management zones: open and partially protected. During the austral summer, 85 individuals of 12 species of elasmobranch were observed over 12 days. No significant differences were observed among sites in either size or abundance for common species. Videos were dominated by Carcharhinus melanopterus (relative abundance±s.d., 0.29±0.90h–1), Nebrius ferrugineus (0.03±0.24h–1) and Urogymnus granulatus (0.08±0.28h–1), which comprised >81% of all individuals. Environmental variables had no measurable effect on the abundance of elasmobranchs. The abundance and diversity of elasmobranchs in Cobourg Marine Park is high compared with other similar turbid, inshore areas of northern Australia. The large number of juveniles observed in our surveys also suggests the possibility of a nursery area.

The rise of the internet coupled with technological innovations such as smartphones have generated massive volumes of geo-referenced data (big data) on human mobility. This has allowed the number of studies of human mobility to rapidly overtake those of animal movement. Today, telemetry studies of animals are also approaching big data status. Here, we review recent advances in studies of human mobility and identify the opportunities they present for advancing our understanding of animal movement. We describe key analytical techniques, potential bottlenecks and a roadmap for progress toward a synthesis of movement patterns of wild animals.

Stable isotope analysis is often used to investigate the trophic ecology of marine systems. However, a lack of standardization of the treatment of samples prior to analysis, hampers comparisons of results within and among studies. This study examined the effects of lipid extraction (LE), acidification for the removal of inorganic carbonate (RIC) and rinsing with deionized water (DIW) on δ13C and δ15N values and C:N ratios in sub-dermal tissue of whale sharks (Rhincodon typus), zooplankton (>200–1000 μm) and a wide range of micronekton (>1000 μm) taxa collected in 2013 and 2014 at Ningaloo Reef (Western Australia). For whale shark tissue, lipid extraction (LE and LE + DIW) increased values of δ13C, whereas LE, LE + DIW and DIW treatments increased values of δ5N and C:N ratios. These results confirm the need to remove lipids and 15N-depleted nitrogenous waste from elasmobranch tissues. The LE + DIW treatment was the most efficient at achieving this goal. For zooplankton and micronekton, LE and RIC treatments had consistent effects on δ13C values, however, effects on δ15N values were more unpredictable. Therefore, zooplankton and micronekton samples should be split into two portions, one subjected to LE or LE + RIC treatments to standardize δ13C values, and a second untreated portion used for analysis of δ15N values. For these taxa, the RIC + DIW treatment resulted in the greatest change in δ15N values, which may confound results. Mathematical normalization models used to predict outcomes of treatments on values of δ13C and δ15N were not found to be suitable for all the taxa in this study.

P.P.andD.R.contributedequallytothisstudyandothershavecontributedequally.Authorshavebeenlistedinalphabeticalorderforeachcontributionlevel.Pepin, P., Robert, D., Bouchard, C., Dower, J. F., Falardeau, M., Fortier, L., Jenkins, G. P., Leclerc, V., Levesque, K., Llopiz, J. K.Meekan, M. G., Murphy, H. M., Ringuette, M., Sirois, P., and Sponaugle, S. Once upon a larva: revisiting the relationshipbetween feeding success and growth in fish larvae. – ICES Journal of Marine Science, doi: 10.1093/icesjms/fsu201.Received7 July 2014; revised 29 September 2014; accepted 18 October 2014.Variationsinlarvalfishgrowthratesarelargelytheresultofvariabilityinbioticandabioticcharacteristicsofthefeedingenvironmentexperiencedbyeachindividual.Anassessmentofanindividual’soverallfeedingsuccess(i.e.accumulationofutilizableorganicmatter)canbestbeachievedatthe time of capture when the relationships among environment, short-term feeding success as defined by gut content and long-term feedingsuccess as defined by accumulated growth can be contrasted. Here, we investigated the relationships between average growth, feeding success,and variability in individual growth and feeding rates across a range of taxa based on a synthesis of studies in which stomach content andotolithgrowthweremeasuredinthesameindividuals.Instantaneousmeasuresoffeedingsuccesswerehighlyvariableanddemonstratedapositiveyetsomewhatlimitedassociationwithgrowthratesacrossalltaxa.Thestrengthofthefeeding-growthrelationshipsamongtaxa,andcohortswithintaxa,wasreflectedintheautocorrelationofindividualgrowthrates,suggestingthatstablegrowthwasachievedthroughconsistentfeedingsuccess.However, when viewed atthe individual level, fastergrowth was achieved in individuals with morevariable growth rates, and by inference morevariablepastfeedingsuccess.Thedichotomyintheseunderlyingrelationshipsmaypointtotheimportanceofstochasticeventsinthedevelop-mentofexceptionalindividualsinapopulation,andmaybelinkedtohowsurplusenergyisallocatedtoindividualgrowthrates.Thepositivecor-relationfoundbetweenfeedingsuccessandgrowthinalltaxaisconsistentwiththegrowth-survivalparadigmforthelarvalstageoffish.However,boththecorrelationbetweenfeedingsuccessandgrowthandtheserialcorrelationofgrowthtime-serieswasgreatestinfast-growingspecies,sug-gesting thatthe potential foran early “critical period” regulatingsurvival varies amongspecies, reaching a maximumin fast-growing fish.Keywords: early life history, gut content, otolith microstructure, recruitment, survival, trophodynamics.

Alternative livelihood projects are criticised as having minimal effect on biodiversity conservation. Studies are rare and where success is claimed, outcomes and reasons why projects work, have not been documented. Livelihoods are an essential element of sustainable integrated coastal management, an accepted framework for conserving coral reefs and marine resources in the tropics. It is not known whether alternative livelihood projects contribute to the goal of improving biodiversity conservation through sustainable integrated coastal management. Here, we examine Oslob Whale Sharks, an alternate livelihoods project in the Philippines built on provisioning whale sharks for community based dive tourism. We investigate how Oslob Whale Sharks contributes to sustainable integrated coastal management and whether it has any effect on biodiversity conservation. Using key stakeholder interviews with artisanal fishers, their community, local politicians and government, we found that Oslob Whale Sharks contributes to all nine factors required for sustainable integrated coastal management. Fishers and local authorities report their perception that whale sharks are protected from poaching and finning and destructive fishing has decreased, while fish abundance, pelagic fish species and catch have increased. Our findings further suggest that as there is little evidence that this type of tourism has any negative impacts on the biology or behaviour of whale sharks, Oslob Whale Sharks provides sustainable livelihoods and a delivery mechanism for sustainable integrated coastal management.

We report observations of a novel feeding behaviour in the moray eel Gymnothorax favagineus (Bloch & Schneider, 1801) and a previously undocumented application of “knotting” behaviour in G. fimbriatus (Bennett, 1832). Moray eels were filmed by baited remote underwater video systems (BRUVS) at the Scott Reefs, a remote group of atoll-like reefs on the edge of the continental shelf in tropical, northwestern Australia. Two behaviours were observed as the moray eels tried to dislodge food from a bait bag: (1) G. favagineus used its tail as a “paddle” to gain leverage on the bag, and (2) G. fimbriatus tied a knot in its tail in order to extract food from the bag. Our observations suggest that morays have an extensive behavioural repertoire for manipulating and extracting large prey items from the interstices of the reefs where they typically hunt.

Little information is available on the movements and behaviour of tropical rays despite their potential ecological roles and economic value as a fishery and a tourism resource. A description of the movement patterns and site fidelity of juvenile rays within a coral reef environment is provided in this study. Acoustic telemetry was used to focus on the use of potential nursery areas and describe movement patterns of 16 individuals of four species monitored for 1–21 months within an array of 51 listening stations deployed across a lagoon, reef crest, and reef slope at Mangrove Bay, Ningaloo Reef, Western Australia. Juveniles used a small (< 1 km2), shallow (1–2 m depth) embayment where three receivers recorded 60–80 % of total detections of tagged animals, although individuals of all species moved throughout the array and beyond the lagoon to the open reef slope. Detections at these primary sites were more frequent during winter and when water temperatures were highest during the day. Long-term use of coastal lagoons by juvenile rays suggests that they provide an important habitat for this life stage. Current marine park zoning appears to provide an effective protection for juveniles within this area.

We thank all the fishers and research staff involved in the CSIRO Northern Pelagics tagging study, Fisheries Research Development Corporation project 2002/064, and the Northern Territory Shark Tagging study for their assistance during tagging and data collection, in particular C. Tarca. The Northern Territory Tagging Study was funded by an Australian Research Council Linkage Grant (LP0667702) to C.J.A.B. and M.G.M., and permitted by the Charles Darwin University Animal Ethics Committee. Additional financial contributions and support were provided by the Northern Territory (NT) Fishing Industry Research and Development Trust Fund, and the Department of Resources (NT). We are especially grateful for the financial and logistic support of R. Lowden, Managing Director of Seafresh Australia, the Northern Territory Seafood Council and W. Mounsey and B. LeMar.

Dietary characteristics and the degree of dietary partitioning by five species of sympatric stingray were assessed using stomach content and sediment analyses within a coral reef lagoon at Ningaloo Reef, Western Australia (the cowtail Pastinachus atrus, blue-spotted fantail Taeniura lymma, blue-spotted mask Neotrygon kuhlii, porcupine Urogymnus asperrimus rays and the reticulate whipray Himantura uarnak). A total of 2804 items were recovered from the stomachs of 170 rays and 3215 individual taxa from the environment, which were used in selectivity analyses. Twenty-four prey taxa were identified from stomach contents and pooled into 10 taxonomic categories for analysis, of which annelids, prawns, brachyurans and bivalves were the most abundant, together accounting for 96% of the diet. Himantura uarnak had the greatest interspecific dissimilarity in diet, consuming a larger proportion of crustaceans, notably penaeids (41% of total diet) than the other four species of rays, all of which had diets dominated by annelids (71-82% of total diet). Crustacean specialization by H. uarnak may exist to maximize resources and reduce competition among sympatric species. The remaining species may partition resources on the basis of space, rather than diet.

We thank the purse-seine vessel owners for access to log-book data and to the Indian Ocean Tuna Commission and the Institut de Recherche pour le Developpement (France), in particular A. Fonteneau, M. Herrera and R. Pianet for data extraction and D. Rowat for data availability and help with interpretation. Our study was funded by Fundacao para a Ciencia e Tecnologia and European Social Funds through A.M.M.S.'s PhD scholarship (SFRH/BD/47465/2008), The University of Adelaide, Australian Institute of Marine Science, Flying Sharks and the Portuguese Association for the Study and Conservation of Elasmobranchs.

Understanding the movements of turtle hatchings is essential for improved understanding of dispersal behaviour and ultimately survivorship, life history strategies and population connectivity. Yet investigation of in-water movement has been hampered by the small size of hatchlings relative to the size of available tracking technologies. This has resulted in the use of labour intensive visual tracking methods, or active tracking methods with high transmitter to body weight ratios. These methods are confounded by the presence of the observer, the size of the tag, usual small treatment sample sizes and studies that are constrained to daylight hours when turtles hatch predominantly at night. Passive acoustic monitoring using new miniature tags can overcome these limitations. We tested the effectiveness of active and passive acoustic tracking in monitoring turtle hatchling movement in order to measure the influence of artificial light on newly hatched turtles once they enter the water. A Vemco VR2W Positioning System (VPS) comprising an array of 18 VR2W receivers was deployed in the surf zone to detect signals from acoustic-coded transmitters (1.14 ± 0.06% of body mass) attached to 26 flatback turtle hatchlings released into the array. A total of 1328 detections were recorded for 22 hatchlings with turtles spending a mean of 16.63 ± 5.89 min in the array. The test detection range for this technology in the surf-zone was 50–100 m and was influenced by wave noise and shallow deployment. Cyclonic conditions hampered the experiment and resulted in an inconclusive test of light effects. Three additional instrumented flatback hatchlings were followed in a small boat using a mobile acoustic receiver and directional hydrophone up to 2 km from shore. Passive acoustic monitoring is a viable technology for tracking small marine animals and removes many of the confounding effects of other telemetry methods. It has great potential to examine natural and anthropogenic factors influencing orientation and behaviour during a crucial stage in turtle life history — their initial movement from the beach through predator-rich, near shore waters. While the data obtained by passive acoustic monitoring is limited in its spatio-temporal coverage, being constrained by the size of the array, active acoustic tracking can be applied over larger scales. Such studies will be particularly important for assessing the impacts of anthropogenic pressures that have changed the natural light, noise or wave environments and for providing behavioural data to improve and validate bio-physical models of the migration and dispersal of young turtles.

Ten years have passed since the last synopsis of whale shark Rhincodon typus biogeography. While a recent review of the species' biology and ecology summarized the vast data collected since then, it is clear that information on population geographic connectivity, migration and demography of R. typus is still limited and scattered. Understanding R. typus migratory behaviour is central to its conservation management considering the genetic evidence suggesting local aggregations are connected at the generational scale over entire ocean basins. By collating available data on sightings, tracked movements and distribution information, this review provides evidence for the hypothesis of broad-scale connectivity among populations, and generates a model describing how the world's R. typus are part of a single, global meta-population. Rhincodon typus occurrence timings and distribution patterns make possible a connection between several aggregation sites in the Indian Ocean. The present conceptual model and validating data lend support to the hypothesis that R. typus are able to move among the three largest ocean basins with a minimum total travelling time of around 2-4 years. The model provides a worldwide perspective of possible R. typus migration routes, and suggests a modified focus for additional research to test its predictions. The framework can be used to trim the hypotheses for R. typus movements and aggregation timings, thereby isolating possible mating and breeding areas that are currently unknown. This will assist endeavours to predict the longer-term response of the species to ocean warming and changing patterns of human-induced mortality.

This study details a simple and cost-effective means of attaching acoustic transmitters to coral reef sharks and stingrays, which potentially allows for retrieval and reuse on completion of tracks. Between 2008 and 2011, galvanised timed releases were trialled in both static field tests and on blacktip reef sharks Carcharhinus melanopterus, cowtail Pastinachus atrus, and porcupine Urogymnus asperrimus rays in Coral Bay (−23°08′41″, 113°45′53″), Western Australia. The timed releases remained attached to animals for the duration required for tracking and in four out of five deployments transmitters were recovered after release from the animals. The use of modified Rototags for sharks and stainless steel darts for stingrays allowed rapid and effective attachment to animals, with limited impact on their welfare in the short term. External attachment for short-term tracking of coral reef-associated elasmobranchs should be considered as a complementary option to internal placement of transmitters in animals either by surgery or by ingestion.