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This article discusses the use of citizen science to observe and document rare behaviors of the spotted eagle ray. The study highlights eight previously unreported resting behaviors of the species, collected from various locations including Australia, the Maldives, and Japan. The findings contribute to our understanding of the behavior and habitat use of this endangered species. The document also emphasizes the value of citizen science in documenting elasmobranch behavior and calls for further research in this area. Additionally, there is a list of references cited in a research article or document related to various species of rays and sharks, providing a comprehensive source for library patrons conducting research on these specific topics. [Extracted from the article]

Whale sharks (Rhincodon typus) are endangered fish with population numbers continuing to decline globally. Botubarani waters, Gorontalo is an aggregation area for whale sharks in Tomini Bay. The high number of tourist visits has created a persistent risk of injury of the whale sharks in the studied area. This research attempts to provide preliminary information regarding the external injury characteristics of Botubarani whale sharks in a descriptive manner, as well as photographic records of the development and rate of natural wound healing in cases of whale sharks suspected of having papilloma disease. Routine data collection during 2019–2023 using the Photographic Identification (Photo-ID) method accompanied by documentation of various types, positions, and severity of wounds on each individual have been carried out to determine the impact of tourism activities as ongoing efforts to protect and preserve whale sharks in Botubarani. The results revealed that 74% (n = 43) of the observed whale sharks had wounds characterized by abrasion nicks and lacerations, mainly located on the dorsal fin, mouth, and head. Although the 88% severity level was a minor injury, the high percentage of abrasion injuries (59.68%) indicated the high impact of friction on the bodies of whale sharks with tourists' boats during feeding. Routine monitoring for 7 months on the papilloma disease case at the Botubarani whale shark tourism site also showed that the healing process of non-anthropogenic wounds due to disease took longer than anthropogenic wounds. It also showed that the papilloma wound had not shown any signs of complete recovery. This research serves as a reference and consideration for Botubarani whale shark tourism managers to reduce the possibility of injury from tourism by creating guidelines for whale shark interactions and restricting tourism vessels from entering the Botubarani whale shark interaction zone. Further, the implementation of baiting techniques is needed to reduce the probability of injury to this endangered species in the future. [ABSTRACT FROM AUTHOR]

Rhincodon typus, or the whale shark, is the largest extant fish in the world and is classified as endangered on the IUCN's Red List. Due to their enormous size and conservation status, whale sharks are rarely housed in aquaria. Here we present a behavioral analysis culminating from a large effort by 89 observers from 2008-2012 to study four R. typus (ID codes: AL, TA, TR, YU) longitudinally in an aquarium setting. We found that relatively simple behavioral metrics such as swim speed, depth occupation, swimming direction, and lead-follow interactions demonstrated R. typus individual variation and responses to habitat changes. All sharks displayed increased swim speeds 30-minutes before regimented feed times, when there was scent of food being fed to other animals in the habitat. Consistently in the habitat, one male shark (YU) was recorded swimming more at depth, faster, almost exclusively clockwise, and engaged in fewer close proximity interactions with others than expected by chance. In contrast, a larger female shark (AL) was observed swimming the slowest, at the surface more than others, led other sharks more than she followed, and had strong lead-follow interactions with another shark of the opposite sex (TA). TA and TR did not differ from each other in depth profiles or speed, but did differ in their proclivity to lead or follow. Depth preferences and lead-follow interactions suggest some partitioning of the habitat and the possibility of social hierarchy in this species. These results represent the first longitudinal behavioral analysis of aquarium R. typus, offering meaningful similarities and contrasts to field observations. [ABSTRACT FROM AUTHOR]

Ultrasound imaging can be used as an effective tool to measure the reproductive status and condition of sharks. This usually requires restraint of the subject, which is not feasible in the wild when the target species is of conservation concern and very large, as is the case for whale sharks. Our study invoked a behavioral response in free-swimming whale sharks that allowed snorkelers to image internal organs and structures using a submersible ultrasound scanner linked to an iPhone in an underwater housing. We were able to reliably locate and monitor the heart and other internal organs inside the body cavity, structures inside the head, and image skin and muscle in the dorsal surface of the sharks. The technique is evaluated as a means for assessing the condition and reproductive status of free-swimming whale sharks. [ABSTRACT FROM AUTHOR]

This document provides a list of scientific articles that focus on the feeding behavior and diet of whale sharks. The articles cover a range of topics, including the prey of whale sharks, their foraging strategies, and their feeding behavior in different locations. The studies utilize techniques such as stable isotope analysis and fatty acid analysis to gain insights into the diet and feeding patterns of these animals. The information presented in these articles is valuable for researchers studying the ecology and conservation of whale sharks. Recently, a rare behavior was observed at Ningaloo Reef in Western Australia, where a whale shark was seen gulping close to the seabed in a vertical position, suggesting that it may be foraging on prey dispersed on the benthos. This observation highlights the flexibility of whale shark foraging behavior and the need for further research in understanding their feeding habits. [Extracted from the article]

Whale mortality and strandings have increased in recent years, with deceased whales often brought to landfill. However, the disposal of whale remains offshore holds significant ecological importance and can be a culturally and ethically sensitive approach. Moreover, offshore disposal mitigates potential risks associated with onshore whale remains disposal, such as the spread of diseases and the logistical challenges of managing large carcasses. A challenge with offshore disposal is defining the best release location to avoid the remains drifting ashore or into shipping channels. Here we compared the drift model outputs using a drift forecast model (SARMAP) for a 14 m whale carcass that was moved offshore in southeast Queensland, Australia, and fitted with a satellite tracker over an observation period of 150 h until positioning signal ceased. The modelling was conducted using different ocean products (BLUElink, HYCOM, and Copernicus), which showed a good agreement with the tracked whale carcass, albeit with changing wind conditions and contrasting currents flowing northward along the coast and, further offshore, flowing south. This case study illustrated that wind was the foremost driver of carcass drift due to the surface area above the water surface. The drift forecast simulations allowed for a reliable prediction of the floating whale drift that can assist authorities with decision making. Offshore disposal of whale carcasses is a sustainable practice but requires good planning and scientific assessment. [ABSTRACT FROM AUTHOR]

This report updates our understanding of whale shark occurrences in The Bahamas by drawing upon a variety of data sources. Our findings reveal previously unreported sighting locations, often associated with tourism activities, underscoring the pivotal role played by nontraditional data sources in addressing knowledge gaps. These revelations emphasize the ongoing necessity for monitoring efforts. Additionally, we have found cases that raise concerns related to unregulated human–shark interactions in the region, highlighting the pressing need for sustainable tourism practices within Bahamian waters. [ABSTRACT FROM AUTHOR]

The population of whale sharks (Rhincodon typus Smith, 1828), the world's largest endangered extant fish species, has declined in the last three decades. Their appearance in the Botubarani Waters has attracted much attention. This study aimed to determine the whale shark's appearance, their habitat constellation pattern during 2019-2022, and its oceanographic conditions. The Photographic Identification (Photo-ID) method is used to observe and determine whale shark individual's number and pattern of presence. Oceanographic data includes chlorophyll-a concentration using Ocean Color Image data and sea surface temperature (SST) using OSTIA image data processed with Interactive Data Language (IDL) software. The research showed there are 38 individuals with an estimated total length of 2.3-7.3 meters. All whale sharks appearing in Botubarani include juvenile male individuals with a composition of 53% new (N=20) and 47% (N=18) old individuals seen again with a rare seasonal and sporadic presence pattern mainly in the Eastern season (June). The average SST value ranged from 28.36-30.29℃ while chlorophyll-a ranged from 0.174-0.698 mg.m-3. Although the present findings show that the whale shark's appearance in Botubarani waters was not significantly influenced by SST and chlorophyll-a, it might be affected by other oceanography factors such as Sea Surface Height Distribution (SSHD) and depth (bathymetry). As the Botubarani aggregation site is the only whale shark emergence area with easy access throughout the year and is rapidly developing into a new ecotourism industry in Indonesia, the information on whale shark appearance provides useful support for their sustainable protection and conservation in the future. [ABSTRACT FROM AUTHOR]

This document provides a list of scientific articles that focus on the study of elasmobranchs (sharks and rays) in the Mediterranean Sea and surrounding areas. The articles cover various topics such as length-weight relationships, feeding ecology, reproduction biology, conservation action plans, data mining, population assessments, and the use of social media for research. These references offer valuable information for library patrons conducting research on elasmobranchs in this region, providing diverse perspectives and culturally sensitive approaches to the study of these species. [Extracted from the article]

Abstract Background To tag large marine vertebrates, without the need to catch them, avoiding using barbs for tag retention, and precisely controlling tag location, the remote Tag Attachment Device on a pole (TADpole) was developed. This allows single-pin tags (Finmount, Wildlife Computers) to be attached to the dorsal fins of free-swimming large marine vertebrates. Results TADpole comprises a pole-mounted holster that carries a tag. It uses compressed air, and a micro-controller, to rapidly insert a stainless-steel pin through a corrodible metal retaining ring in the first tag attachment wing, the animal’s dorsal fin, and then a press fit Delrin retaining ring in the tag wing on the other side of the fin. Tagging only occurs when the trailing edge of the dorsal fin touches a trigger bar in the holster, ensuring optimal pin placement. It was developed using fins from cadavers, then trialed on briefly restrained coastal dolphins that could be followed in successive days and weeks, and then on free-swimming animals in the field. The latter showed very short touch/response intervals and highlighted the need for several iterative revisions of the pneumatic system. This resulted in reducing the total time from triggering to tag application to ~ 20 ms. Subsequent efforts expanded the TADpole’s applicability to sharks. One free-swimming Atlantic spotted dolphin, two white sharks, and one whale shark were then tagged using the TADpole. Conclusions Being able to tag free-swimming dolphins and sharks remotely and precisely with satellite-linked telemetry devices may contribute to solving conservation challenges. Sharks were easier to tag than dolphins. Dolphin touch-to-response times were 28 ms or less. Delphinid skin has unique polymodal axon bundles that project into the epidermis, perhaps a factor in their uniquely fast response, which is 10 × faster than humans. Their primary reaction to tagging is to abduct the flippers and roll the fin out of the TADpole holster. This device has the potential to deliver high-quality tag data from large vertebrates with dorsal fins without the stress and logistics associated with catch-and-release, and without the trauma of tags that use barbs for retention. It also collects a dorsal fin biopsy core.

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This article explores the presence of site fidelity, or philopatry, in blue sharks. While blue sharks are typically known for their wide-ranging movements, this study documents the repeated sightings of two blue sharks at a specific location in the Azores archipelago. The sharks were attracted to the area by local dive operators who regularly provide food. These findings challenge the belief that blue sharks are strictly oceanic wanderers and suggest that they may exhibit some form of site fidelity to predictable feeding areas. The study emphasizes the importance of citizen science and collaboration between scientists and the diving industry in gathering valuable information for the management and conservation of marine migratory species. However, further research using longer-term satellite telemetry is necessary to gain a better understanding of the behavioral ecology of these sharks and its implications for their management and conservation. [Extracted from the article]

In recent years, new findings and new methods (stable isotopes of oxygen, zinc, and nitrogen; 2D and 3D modeling; and geometric morphometric analyses of the teeth) have enhanced our knowledge of the Neogene shark fauna and its paleobiology. Several papers deal with the large Otodus (Megaselachus) species, including the construction of a 3D model, as well as insights into its lifestyle and diet. In addition, the skeletal remains of Carcharias gustrowensis, Carcharodon hastalis, and Keasius parvus and a natural tooth set of Carcharodon hubbelli have been described in the last 13 years, and the dentition of the Neogene species Carcharoides catticus, Megachasma applegatei, and Parotodus benedenii has been reconstructed. Stable isotope analyses of the teeth from the Neogene species of Araloselachus, Carcharias, Carcharodon, Galeocerdo, Hemipristris, and Mitsukurina have given insights into the trophic positions of these genera during the Neogene, and shark teeth preserved near the skeletal remains of prey animals (mammals) and shark bite traces on these remains provide direct evidence of trophic interactions. The tooth shape, fossil locality, and paleoenvironment have been used to better understand the taxa Carcharhinus dicelmai, Megalolamna paradoxodon, Pachyscyllium dachiardii, and P. distans. Among extant species, Galeorhinus galeus can be traced back to the Eocene. Alopias superciliosus, Rhincodon typus, and possibly A. vulpinus can be traced back to the Oligocene. Species present by the Miocene include Alopias vulpinus, Carcharhinus amblyrhynchoides, C. amblyrhynchos, C. albimarginatus, C. amboinensis, C. brachyurus, C. brevipinna, C. falciformis, C. glaucus, C. leucas, C. limbatus, C. longimanus, C. macloti, C. obscurus, C. perezi, C. sealei, Centrophorus granulosus, Cetorhinus maximus, Dalatias licha, Deania calcea, Galeocerdo cuvier, Glyphis glyphis, Heptranchias perlo, Isurus paucus, Lamna nasus, Negaprion brevirostris, Odontaspis ferox, Pseudocarcharias kamoharai, Sphyrna media, S. mokarran, and possibly Carcharodon carcharias. First appearing in the Pliocene are Scymnodon ringens, Somniosus rostratus, and Zameus squamulosus. For some extant species (Carcharias taurus, Hexanchus griseus, Isurus oxyrinchus, Notorynchus cepedianus, and Sphyrna zygaena), it is not clear whether the assigned Neogene teeth represent the same species. The application of new methods to more fossil shark taxa, a detailed search for shark fossils, and better knowledge of the dentition of extant species (especially those with minute-sized teeth) will further enhance our knowledge of the evolution and paleobiology of sharks. [ABSTRACT FROM AUTHOR]

This study explored tourists' blogs to identify sustainability challenges and opportunities to inform best-practice management of the whale shark tourism industry worldwide. Few researchers have investigated blogs in the context of swim‐with whale shark experiences as recounted from the tourist perspective. This research was based on a content analysis of a sample of 58 tourist blogs, amounting to 31,509 words of content. The findings explored common sustainability themes within the whale shark tourist experience including proximity of the encounter, nature of the interaction, and whale shark tourist behavior. By comparing three whale shark tourism destinations–Mexico, the Philippines, and Australia–several sustainability challenges and opportunities were identified. The findings contribute to previous knowledge by advancing our understanding of whale shark tourists' perception of critical aspects during their swim-with whale shark experience, which guided recommendations for improved and sustainable management. [ABSTRACT FROM AUTHOR]

As the use of coastal and offshore environments expands, there is a need to better understand the exposure of marine megafauna to anthropogenic activities that potentially threaten their populations. Individual satellite telemetry studies are often hampered by small sample sizes, providing limited information on spatiotemporal distributions of migratory animals and their relationships to anthropogenic threats. We addressed this issue by synthesising satellite tracking data from 484 individuals of three taxonomic groups and six species; three marine turtle, two whale and one shark. The spatial overlap between taxa distributions and multiple anthropogenic activities was assessed as a proxy for the cumulative exposure of these taxa to anthropogenic threats (coastal modification, vessel strike, underwater noise, oil spill, bycatch, entanglement, and artificial light) across an area totalling 2,205,740 km2 off north-western Australia. Core exposure areas (top 50% of the distribution) encompassed ecologically important sites for all taxa, such as the Ningaloo and Pilbara regions, migratory routes for whales and sharks in offshore waters beyond Ningaloo Reef, and marine turtle nesting beaches at Barrow Island and Cape Lambert. Although areas of high exposure represented <14% of taxa distributions, we showed that no taxa occurred in the absence of threats and that even areas with existing spatial protections are experiencing high levels of exposure. Importantly, we developed a robust approach for documenting the potential exposure of marine species to a range of human activities at appropriate spatial scales to inform conservation management. [ABSTRACT FROM AUTHOR]

Context: Assessing the distribution and abundance of marine fauna and the ecological status of coastal and pelagic ecosystems is key to biodiversity conservation, but the monitoring of mobile marine species raises multiple logistical and financial challenges. Aims: The project describes the distribution, abundance and taxonomic assemblage of several marine megafauna taxa in three subregions of the western and central South Pacific Ocean (New Caledonia, Wallis and Futuna, and French Polynesia). Methods: Large-scale aerial surveys were conducted using a standardised multi-taxon protocol, to characterise the occurrence and abundance of marine megafauna over 2.5 million km2. Analysing more than 122 000 km of transects, the densities of 22 different taxa were estimated: seven taxonomic groups of marine mammals (Physeteridae, Kogiidae, Ziphiidae, Globicephalinae, Small Delphininae, Large Delphininae, and Dugongidae), a single group for hard-shelled sea turtles, three groups of elasmobranchs (including whale sharks), and 11 groups of seabirds (including Phaethontidae, Hydrobatidae, Fregatidae and Sulidae). Key results: Contrasting patterns of species distribution were found. Marine mammal diversity increases north and west, with a distinct species assemblage in New Caledonia, compared to other subregions. A strong latitudinal gradient was observed across French Polynesia, independent of taxa. Conclusions: This study provides the first comparison of marine species assemblages across the three oceanic subregions and sets a regional baseline for the biogeography of marine megafauna in the region. Implications: The taxonomic and spatial extension of the results opens up new perspectives for the development of local conservation measures, especially for taxa with already documented population declines. This study simultaneously describes the spatial distribution and densities of 22 distinct taxonomic groups of marine mammals, sea turtles, elasmobranchs and seabirds over three large oceanic subregions of the western and central South Pacific Ocean. It demonstrates the value of multi-taxa monitoring applied to aerial surveys of offshore marine megafauna, and provides a baseline for future conservation measures. This article belongs to the Collection Marine Mammals in the Pacific. [ABSTRACT FROM AUTHOR]

The Golden Trevally, Gnathanodon speciosus , is a large predatory fish with an extremely broad tropical Indo-Pacific distribution that crosses many biogeographical boundaries. Both published information and freely available imagery suggest that small juvenile G. speciosus are often associated with whale sharks, Rhincodon typus ; an association that could explain the unusually widespread distribution of G. speciosus , and suggests a novel nursery relationship. The possibility of such an association has the potential to reshape our understanding of the ecological roles played by long-range migrants such as R. typus and other megafauna, our understanding of the full extent of their conservation value, and how we manage both members of the relationship. The Golden Trevally, Gnathanodon speciosus , is a large predatory fish with an extremely broad tropical Indo-Pacific distribution crossing many biogeographical boundaries. Published information and freely available imagery suggest that small juvenile G. speciosus are often associated with whale sharks, Rhincodon typus ; an association that could explain their unusually wide-spread distribution, and suggests a novel nursery relationship. The occurrence of such an association reshapes our understanding of the ecological roles played by long-range migrants such as R. typus and other megafauna. [ABSTRACT FROM AUTHOR]

Rhincodon typus, or the whale shark, is the largest extant fish in the world and is classified as endangered on the IUCN’s Red List. Due to their enormous size and conservation status, whale sharks are rarely housed in aquaria. Here we present a behavioral analysis culminating from a large effort by 89 observers from 2008–2012 to study four R. typus (ID codes: AL, TA, TR, YU) longitudinally in an aquarium setting. We found that relatively simple behavioral metrics such as swim speed, depth occupation, swimming direction, and lead-follow interactions demonstrated R. typus individual variation and responses to habitat changes. All sharks displayed increased swim speeds 30-minutes before regimented feed times, when there was scent of food being fed to other animals in the habitat. Consistently in the habitat, one male shark (YU) was recorded swimming more at depth, faster, almost exclusively clockwise, and engaged in fewer close proximity interactions with others than expected by chance. In contrast, a larger female shark (AL) was observed swimming the slowest, at the surface more than others, led other sharks more than she followed, and had strong lead-follow interactions with another shark of the opposite sex (TA). TA and TR did not differ from each other in depth profiles or speed, but did differ in their proclivity to lead or follow. Depth preferences and lead-follow interactions suggest some partitioning of the habitat and the possibility of social hierarchy in this species. These results represent the first longitudinal behavioral analysis of aquarium R. typus, offering meaningful similarities and contrasts to field observations.

Background: Measuring coastal-pelagic prey fields at scales relevant to the movements of marine predators is challenging due to the dynamic and ephemeral nature of these environments. Whale sharks (Rhincodon typus) are thought to aggregate in nearshore tropical waters due to seasonally enhanced foraging opportunities. This implies that the three-dimensional movements of these animals may be associated with bio-physical properties that enhance prey availability. To date, few studies have tested this hypothesis. Methods: Here, we conducted ship-based acoustic surveys, net tows and water column profiling (salinity, temperature, chlorophyll fluorescence) to determine the volumetric density, distribution and community composition of mesozooplankton (predominantly euphausiids and copepods) and oceanographic properties of the water column in the vicinity of whale sharks that were tracked simultaneously using satellite-linked tags at Ningaloo Reef, Western Australia. Generalised linear mixed effect models were used to explore relationships between the 3-dimensional movement behaviours of tracked sharks and surrounding prey fields at a spatial scale of ~ 1 km. Results: We identified prey density as a significant driver of horizontal space use, with sharks occupying areas along the reef edge where densities were highest. These areas were characterised by complex bathymetry such as reef gutters and pinnacles. Temperature and salinity profiles revealed a well-mixed water column above the height of the bathymetry (top 40 m of the water column). Regions of stronger stratification were associated with reef gutters and pinnacles that concentrated prey near the seabed, and entrained productivity at local scales (~ 1 km). We found no quantitative relationship between the depth use of sharks and vertical distributions of horizontally averaged prey density. Whale sharks repeatedly dove to depths where spatially averaged prey concentration was highest but did not extend the time spent at these depth layers. Conclusions: Our work reveals previously unrecognized complexity in interactions between whale sharks and their zooplankton prey. [ABSTRACT FROM AUTHOR]

The presence of brominated flame retardants in Mexico is discussed and a prospective analysis is proposed. Through a bibliographic review of 16 scientific research articles, the presence of these compounds in coasts, soils, landfills, coastal lagoons and effluents from wastewater treatment plants, in the eggs of the aplomado falcon and in the skin of the whale shark has been reported. These compounds have also been found in the blood of Mexicans living in some states of the country. The presence of these contaminants in other Mexican environments and their effects on their biota are unknown. More studies are required to expand knowledge on this subject. [ABSTRACT FROM AUTHOR]

The whale shark (Rhincodon typus) is a filter-feeding organism that can be considered a sentinel species, and Bahía de los Ángeles (BLA) in the Gulf of California is an important sighting site for these elasmobranchs. This filter-feeding organism can be considered a pollutant sampler from the marine environment. Persistent organic pollutants are toxic compounds with high mobility and environmental persistence, bioaccumulation and trophic transfer. Among these are polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). The present work aimed to determine concentrations of PAHs and OCPs in whale shark skin biopsies, collected in 2021 at BLA. Mean detected levels of PAHs and OCPs were 279.4 ng/g dw (dry weight) and 1478.1 ng/g dw, respectively. Analysis of similarities between the ordered sizes (4.2–7.6 m) and the concentrations of PAHs and OCPs indicated no significant differences. Individual PAHs detected indicate pyrogenic and petrogenic sources; the presence of pesticides at levels higher than those of hydrocarbons may be related to agricultural activity in the areas surrounding the Baja California peninsula. This study is the first report of PAH levels in R. typus for the Gulf of California and Mexico. [ABSTRACT FROM AUTHOR]

As the use of coastal and offshore environments expands, there is a need to better understand the exposure of marine megafauna to anthropogenic activities that potentially threaten their populations. Individual satellite telemetry studies are often hampered by small sample sizes, providing limited information on spatiotemporal distributions of migratory animals and their relationships to anthropogenic threats. We addressed this issue by synthesising satellite tracking data from 484 individuals of three taxonomic groups and six species; three marine turtle, two whale and one shark. The spatial overlap between taxa distributions and multiple anthropogenic activities was assessed as a proxy for the cumulative exposure of these taxa to anthropogenic threats (coastal modification, vessel strike, underwater noise, oil spill, bycatch, entanglement, and artificial light) across an area totalling 2,205,740 km[sup 2] off north-western Australia. Core exposure areas (top 50% of the distribution) encompassed ecologically important sites for all taxa, such as the Ningaloo and Pilbara regions, migratory routes for whales and sharks in offshore waters beyond Ningaloo Reef, and marine turtle nesting beaches at Barrow Island and Cape Lambert. Although areas of high exposure represented <14% of taxa distributions, we showed that no taxa occurred in the absence of threats and that even areas with existing spatial protections are experiencing high levels of exposure. Importantly, we developed a robust approach for documenting the potential exposure of marine species to a range of human activities at appropriate spatial scales to inform conservation management. [ABSTRACT FROM AUTHOR]

Citizen science in coastal ecosystems often involve (eco-)tourists that actively monitor reefs, species and pollution. Data collected by tourists, passively, was used to gain insight into landings of the largest fish, the whale shark (Rhincodon typus), in Pangandaran Bay, Indonesia. Monitoring of illegal fishing was halted due to COVID-19 travel restrictions and lockdowns. With two million, mainly Indonesian, tourists visiting Pangandaran Bay in 2020 (30% less than in 2019) enough tourists were present to record landings of whale sharks. Monitoring social media revealed reports of 10 whale shark landings between August 2020 and August 2022. Seven were in July–August of immatures 6–7 m in length. The information passively provided by tourists since COVID-19 have given insights into the biology of whale sharks, landing risks and how communities interact with sharks. Feeding back this information to tourists is challenging, yet vital, to cement a sense of belonging, purpose and attachment to their holiday location. [ABSTRACT FROM AUTHOR]

Baitfishes may aggregate around megafauna such as whale sharks (Rhincodon typus) to gain protection from larger predatory fishes. Here, we used videos from deployments of animal-borne cameras on whale sharks and provided by tourism operators at Ningaloo Reef in Western Australia to document large schools of trevally (Carangidae spp.) consuming entire schools of baitfishes (Carangidae spp.) swimming with whale sharks within 2–45 s. These videos showed that small baitfishes are still very vulnerable to predatory fishes when accompanying whale sharks, refuting the hypothesis that whale sharks provide baitfishes shelter from predators. It thus seems more likely that the association between whale sharks and baitfishes may confer other advantages such as reduced costs of locomotion and/or enhanced feeding opportunities for baitfishes rather than protection from predation. [ABSTRACT FROM AUTHOR]

As the use of coastal and offshore environments expands, there is a need to better understand the exposure of marine megafauna to anthropogenic activities that potentially threaten their populations. Individual satellite telemetry studies are often hampered by small sample sizes, providing limited information on spatiotemporal distributions of migratory animals and their relationships to anthropogenic threats. We addressed this issue by synthesising satellite tracking data from 484 individuals of three taxonomic groups and six species; three marine turtle, two whale and one shark. The spatial overlap between taxa distributions and multiple anthropogenic activities was assessed as a proxy for the cumulative exposure of these taxa to anthropogenic threats (coastal modification, vessel strike, underwater noise, oil spill, bycatch, entanglement, and artificial light) across an area totalling 2,205,740 km2 off north-western Australia. Core exposure areas (top 50% of the distribution) encompassed ecologically important sites for all taxa, such as the Ningaloo and Pilbara regions, migratory routes for whales and sharks in offshore waters beyond Ningaloo Reef, and marine turtle nesting beaches at Barrow Island and Cape Lambert. Although areas of high exposure represented

Simple Summary: One of the least understood and most threatened groups of elasmobranchs is the Rhinopristiformes, the guitarfishes, wedgefishes, and sawfishes. Numbering more than 60 species, this order includes a high percentage of Critically Endangered and Endangered species, as designated by the International Union for the Conservation of Nature. There is a dearth of data on these species due to sightings being infrequent and unpredictable. Globally, Rhinopristiformes are both directly targeted for their meat and large fins and are caught as bycatch in their near-shore habitats. We report here a consistent and predictable long-term presence of the Critically Endangered bowmouth guitarfish (Rhina ancylostomus) in the Gulf of Tadjoura, Djibouti. This species has been reliably encountered during diving and whale shark research activities (November–February) over seven seasons, indicating long-term site fidelity of R. ancylostomus within the area. Currently receiving minimal legal protection and facing unknown fishing pressures and ecological risks, these animals and their habitat should be prioritized for research and conservation. The bowmouth guitarfish (Rhina ancylostomus) is among the most endangered of marine vertebrates, and evidence of severe declines and localized extinctions has been reported. Yet its life history and ecology suffer from a lack of scientific attention due to the scarcity and unpredictable movements of the species. By collecting opportunistic records from 2015 to 2023 during diving activities, this study describes for the first time the occurrence of a predictable aggregation of R. ancylostomus in the Gulf of Tadjoura (Djibouti). These data provide a key record of this species in the area, whose presence is strongly associated with sandy seabeds and corals at approximately 35 m depth. Based on the opportunistic sightings of R. ancylostomus during diving activity, Ras Eiro and Ras Korali appear to be the currently known core habitats for this species and may serve as breeding or feeding grounds. Overall, our data show that the Gulf of Tadjoura is a globally important conservation hotspot, and therefore its protection should be prioritized. [ABSTRACT FROM AUTHOR]

Shark populations globally are facing catastrophic declines. Ecotourism has been posited as a potential solution to many of the issues facing shark conservation, yet increasingly studies suggest that such activity may negatively influence aspects of shark ecology and so further pressure declining populations. Here we combine UAV videography with deep learning algorithms, multivariate statistics and hidden Markov models (HMM) to quantitatively investigate the behavioural consequences of ecotourism in the whale shark (Rhincodon typus). We find that ecotourism increases the probability of sharks being in a disturbed behavioural state, likely increasing energetic expenditure and potentially leading to downstream ecological effects. These results are only recovered when fitting models that account for individual variation in behavioural responses and past behavioural history. Our results demonstrate that behavioural responses to ecotourism are context dependent, as the initial behavioural state is important in determining responses to human activity. We argue that models incorporating individuality and context-dependence should, wherever possible, be incorporated into future studies investigating the ecological impacts of shark ecotourism, which are only likely to increase in importance given the expansion of the industry and the dire conservation status of many shark species. [ABSTRACT FROM AUTHOR]

Simple Summary: Illegal fishing, including that of sharks for meat and fins, is one of the larger threats to marine biodiversity conservation. Getting data on these illegal activities is challenging as there are few reliable official records. I use data from the media, tourists, and artisan fishermen to gain insight into the trade in the world's largest fish, the whale shark, in Indonesia. Whale sharks are typically caught in fishing nets, dragged alongside boats to the shallows, where they are butchered. The meat and oil are sold. In a popular tourist area, Pangandaran, whale sharks are landed and butchered on the beach in view of hundreds of people and local media; I report on 30 landings (2002–2022). Along the south coast of Java, part of which includes Pangandaran, I document 38 landings (2019–2022). Artisanal fishermen see the landings of whale sharks as fortuitous events, and the monetary gains are frequently shared with the community. However, artisanal fisheries pose a significant threat to whale sharks, and the legal protection that whale sharks receive in Indonesia is not sufficiently enforced. Furthermore, Indonesia is a signatory to various international agreements that preclude the fishing and trade in whale sharks, and greater adherence to these rules and regulations is needed. Illegal, unreported, and unregulated fishing, including that of sharks, poses a significant threat to marine ecosystems and individual species. I use data from the media, tourists, and artisan fishermen to gain insight into the trade in the world's largest fish, the whale shark (Rhincodon typus). I focus on the Indonesian island of Java where, along its south coast, whale sharks are landed and butchered on the beach in view of hundreds of people and local media. Whale sharks are typically caught in fishing nets and dragged alongside boats to the shallows, where they are butchered. The meat and oil (valued at ~USD 2000 per shark) are sold and distributed within the community. I document 58 landings of mainly immature whale sharks (2002–2022). Artisanal fishermen see the landing of whale sharks as a fortuitous event, but the species is protected, and Indonesia is a signatory to various international agreements that preclude the fishing of whale sharks. It is imperative for the conservation of whale sharks that the various parties in Indonesia adhere better to their own rules and regulations protecting this species. [ABSTRACT FROM AUTHOR]

Microbiomes confer beneficial physiological traits to their host, but microbial diversity is inherently variable, challenging the relationship between microbes and their contribution to host health. Here, we compare the diversity and architectural complexity of the epidermal microbiome from 74 individual whale sharks (Rhincodon typus) across five aggregations globally to determine if network properties may be more indicative of the microbiome-host relationship. On the premise that microbes are expected to exhibit biogeographic patterns globally and that distantly related microbial groups can perform similar functions, we hypothesized that microbiome co-occurrence patterns would occur independently of diversity trends and that keystone microbes would vary across locations. We found that whale shark aggregation was the most important factor in discriminating taxonomic diversity patterns. Further, microbiome network architecture was similar across all aggregations, with degree distributions matching Erdos–Renyi-type networks. The microbiome-derived networks, however, display modularity indicating a definitive microbiome structure on the epidermis of whale sharks. In addition, whale sharks hosted 35 high-quality metagenome assembled genomes (MAGs) of which 25 were present from all sample locations, termed the abundant 'core'. Two main MAG groups formed, defined here as Ecogroup 1 and 2, based on the number of genes present in metabolic pathways, suggesting there are at least two important metabolic niches within the whale shark microbiome. Therefore, while variability in microbiome diversity is high, network structure and core taxa are inherent characteristics of the epidermal microbiome in whale sharks. We suggest the host-microbiome and microbe-microbe interactions that drive the self-assembly of the microbiome help support a functionally redundant abundant core and that network characteristics should be considered when linking microbiomes with host health. [ABSTRACT FROM AUTHOR]

Despite being the world's largest fish, many questions remain regarding the ecology and behaviour of the whale shark (Rhincodon typus). We present the first direct evidence of whale sharks engaging in bottom‐feeding behaviour and provide potential explanations for this foraging strategy. We suggest that whale sharks actively feed on benthic prey, either predominantly in deepwater environments or where the abundance of such prey exceeds that of planktonic food sources. We also highlight the potential for ecotourism and citizen science projects to contribute to our understanding of marine megafauna behavioural ecology. [ABSTRACT FROM AUTHOR]

Seas and oceans are contaminated by persistent organic pollutants (POPs), which are released into the environment by human activities. The chemical-physical properties of POPs induce high persistence and toxicity in marine organisms from the lowest to the highest trophic levels. Phyto- and zooplankton are at the base of the food chain, and they can adsorb and accumulate these xenobiotic compounds. Therefore, all planktophagous species, including the whale shark (Rhincodon typus), are susceptible to ingesting these contaminants during feeding. From October to December, whale sharks migrate along the north-west coast of Madagascar in search of dense patches of plankton. During scientific expeditions to the whale sharks' foraging areas in the waters of the island of Nosy Be (which is in the north-west of Madagascar), plankton samples were taken. In these samples, the presence and levels of some chlorinated xenobiotics (HCB, DDT and its metabolites, and PCBs) were evaluated in order to estimate the possible impact of whale shark diet on organochlorine (OC) accumulation. The fresh plankton biomass sampled from this region did not seem to be sufficient for the sustenance of the animals, which suggests that the daily contamination input of Rhincodon typus individuals, depending on their plankton diet, is minimal. [ABSTRACT FROM AUTHOR]

Megamouth sharks Megachasma pelagios Taylor, Compagno, and Struhsaker, 1983, are a large-bodied, planktivorous, deep-sea species with peculiar morphology. Since their initial description in the late 20th century, many individuals of different sizes have been reported, but few studies examined ontogenetic changes in body shapes. Here, we assess the growth changes in their heads and fins based on length measurements from nine different-sized individuals (177–544 cm in total length). Bivariate analyses showed that the head becomes larger relative to body length with increasing body size (i.e., positive allometry), whereas the relative size of the caudal fin remains constant (i.e., isometric growth). This trend differs from basking sharks and apparently resembles whale sharks and some baleen whales, although they are all large-bodied filter feeders. Given that relative mouth size is linked to feeding modes, our results suggest that megamouth sharks have different feeding modes from ram-feeding basking sharks and may have some similarity with suction-feeding whale sharks and engulfment-feeding baleen whales. [ABSTRACT FROM AUTHOR]

Each year, whale sharks (Rhincodon typus) aggregate in the northern Gulf of California at Bahia de los Angeles, a small coastal village that recently developed whale shark swimming as economic activity during the summer and autumn. Since the number of animals using the bay fluctuates annually, we aimed to predict it 1 month before each whale shark season. We based our modelling approach on the hypothesis that interannual warming conditions would spatially restrict whale shark habitats, triggering larger aggregations in areas that remain productive.We photo‐identified whale sharks while surface feeding in Bahia de los Angeles during a 13‐year period, which allowed us to estimate a local abundance index per year through mark–recapture techniques. Then, we fitted these abundances as a function of several competing model structures, based on means of sea surface temperature and chlorophyll‐a, as well as their interannual anomalies from the linear trend, during spring, within the best‐known range of the species in the northern Gulf of California.The results of the ecological model showed that whale sharks visit Bahia de los Angeles in larger numbers during extreme warming conditions, with relatively high surface chlorophyll‐a concentrations, which was especially evident during the 2014–2016 northeast Pacific Marine Heatwave and El Niño. Presumably, the overall reduction in surface productivity associated with these events forced whale sharks to restrict their summer–autumn habitat to productivity hotspots, including Bahia de los Angeles.Our model allowed us to predict the number of animals visiting the site before each season starts, which has crucial proactive management implications, such as allowing authorities to regulate the ecotourism effort dynamically to reduce the probability of ship strikes and/or excessive stress to the animals. We propose an abundance baseline from the prediction for neutral interannual conditions.Synthesis and applications. We recommend local authorities apply the model described in this study during the late spring of each year to obtain predictions of the upcoming whale shark abundance and establish the maximum ecotourism effort allowed accordingly. [ABSTRACT FROM AUTHOR]

Understanding the diet of whale sharks (Rhincodon typus) is essential for the development of appropriate conservation strategies for the species. This study evaluated the use of the parasitic copepod (Pandarus rhincodonicus) as a proxy to infer short-term foraging habitats and trophic positions of whale shark hosts. To accomplish this, bulk stable carbon (δ13C) and nitrogen (δ15N) isotope compositions were analysed from 72 paired samples of whale shark skin (dermal) tissues and copepods collected across six years at the Ningaloo Reef aggregation site, Western Australia. This study found that δ15N from parasites and whale shark hosts were strongly correlated. As turn-over times of the parasite and whale shark differ (months vs. years, respectively), the ability of copepods to predict δ15N values indicates that the trophic positions of whale sharks remain consistent across these timeframes. Contrastingly, δ13C in the parasite and host were weakly correlated, likely reflecting differences in the physiology and lifecycle of the copepod parasite compared to the host. Our results suggest δ15N from parasitic copepods provides a reliable proxy of the trophic position of their whale shark hosts, but interpretation of δ13C values as a proxy for the host will require future studies on the lifecycle of P. rhincodonicus. [ABSTRACT FROM AUTHOR]