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Aim Understanding the spatial and temporal variation in the distribution of migratory species is critical for management and conservation efforts. However, challenges in observing mobile marine species throughout their migratory pathways can impede the identification of critical habitat, linkages between these habitats and threat-mitigation strategies. This study aimed to gain insight into the long-term residency and movement patterns of the whale shark (Rhincodon typus) and to reveal important habitat in the context of R. typus usage of existing Marine Protected Areas (MPAs). Location South-eastern Indian Ocean. Methods Satellite telemetry was used to remotely track the long-term movements of 29 R. typus, and to quantify shark usage of the existing MPA network. From the tracking data and environmental predictors, nonlinear models were developed to predict suitable R. typus habitat throughout the south-eastern Indian Ocean. Results This study includes the first documented complete return migrations by R. typus to Ningaloo Marine Park, which was found to be an important area for R. typus all year-round. We found that while existing MPAs along Australia's west coast do afford some protection to R. typus, telemetry-based habitat models revealed large areas of suitable habitat not currently protected, particularly along the Western Australian coast, in the Timor Sea, and in Indonesian and international waters. Main conclusions Animal-borne telemetric devices allowed the gathering of long-term spatial information from the elusive and highly mobile R. typus, revealing the spatial scale of their migration in the south-eastern Indian Ocean. Suitable habitat was predicted to occur inside conservation areas, but our findings indicate that the current MPA network may not sufficiently protect R. typus throughout the year. We suggest that telemetry-based habitat models can be an important tool to inform conservation planning and spatial management efforts for migratory species.

Background Whale sharks (Rhincodon typus) are generally sighted during daytime. In the southern atolls of Maldives they are instead sighted primarily at night inside the atoll. Tuna fishermen attract baitfish with a strong halogen lamp, creating substantial plankton concentrations. Whale sharks opportunistically feed near the surface under fishing boats anchored in a 40 m deep lagoon, often disturbing bait collection. This unique occurrence is well known locally but not internationally and it has yet to be the focus of a targeted research program, due in part to the remoteness of the area. This study aims to provide preliminary answers for the following question: Are whale sharks simply moving through Thaa Atoll or do they remain inside for an extended period? Approach Two sharks were tagged in December 2015, while feeding at night under the light of fishing boats inside Thaa Atoll. Wildlife Computers SPOT 5 satellite tags, secured via non-invasive fin clamps, were deployed on the first dorsal fin of two sharks to monitor their geographic movements. This pilot tagging project was undertaken in conjunction with a photo identification study (using Wildbook for Whale Sharks), to compare to other photo ID data collected during other sighting events before and after tagging. Results The first shark (M-109) retained the tag for a period of 25 days, and appeared to remain inside the atoll during this period. Frequent movements within the atoll were recorded, up to 20 km over a 24 h period. M-109 was regularly recorded at the northeast area within the atoll, near a consistent baitfish collection ground where this individual was originally tagged. However, on occasion, M-109 was recorded far from bait collection areas and/or during rough nights with no fishing activity, suggesting natural surface feeding behavior. Despite no data forthcoming from the second tagged shark (likely because of tag dislodgement through interaction with fishers nets), this individual was resighted (confirmed through photo-identification) feeding under fishing nets, at a similar location to the first sighting, 22 days later. Conclusions 1) Satellite data, for M-109, and photo-identification data, for the second shark, confirmed both sharks inside the atoll over a 25 and 22 day period respectively, leading to the possibility of an extended stay throughout the Maldivian dry season. 2) Tagged whale shark M-109 was confirmed via satellite uplinks inside Thaa Atoll on 24 of 25 days for which we have data, suggesting it did not leave the atoll during the 25 day monitoring period. M-109 showed extensive movement within the atoll, far from bait collection areas, suggesting that local fisheries may not be the only source of food exploited by whale sharks. While the results are preliminary, the next phase of research in this potential seasonal whale shark sanctuary will focus on: establishing the frequency of fisher/shark interactions within Thaa Atoll; productivity/plankton studies inside the atoll; an increased number of whale sharks satellite-tagged; expansion of photo-identification work. This study represents the first whale shark tagging study officially recognized and permitted by the Maldivian government and it was performed under governmental supervision. It represents a milestone for the future of whale shark tracking research in the country.

Background Prior to 1999, the conservation status of the biggest fish in the sea was listed by the World Conservation Union (IUCN) as ‘Indeterminate – Data Deficient’ in its Red List of Threatened Species publication. A Species Report was commissioned in 1999 and the Whale Shark's status was subsequently upgraded to ‘Vulnerable’ in 2000. Much attention has been afforded this species since 2000, with various protective measures implemented at the local, national and international scale. But has it had any effect? Approach Literature Review and discussions with stakeholders from across the globe was used to investigate the current state of play. A recent updated IUCN Red List Report was also consulted. Areas of concern are highlighted and suggested ways forward discussed. Results Whale Sharks are listed under many international conventions e.g. the United Nations Convention on the Law of the Sea (UNCLOS); the Bonn Convention for the Conservation of Migratory Species of Wild Animals (CMS); the Convention on International Trade in Endangered Species (CITES). There is however little evidence of actions under these Conventions. The Whale Shark is known to occur in the waters of more than 100 countries – yet it receives protection in less than 50% of these. One country that lists protection for this species is China – the location of the largest active commercial whale shark fishery. Yet enforcement of existing laws is lacking. A review of the conservation status for the Whale Shark was undertaken in 2015 resulting in no change to its ‘Vulnerable’ assessment in the IUCN's 2016 Red List. The main threats are fisheries catches, bycatch in nets, vessel strikes, whale shark tourism, marine pollution, and the inability for implementation/actions under current laws and Conventions. Conclusions Where are we failing – and what needs to be done? For a start, we need better information, starting with regional and global population assessments to establish population trends globally (at present ‘unknown’ in the latest Red List Assessment). We need improved monitoring of threats and the means to implement adjustments as required (including tourism activities) to minimise impacts. We must have an increased level of data sharing: greater collaboration between researchers, especially to maximise the use of limited available resources to achieve tangible outcomes (which can then be reviewed by relevant authorities when implementing conservation measures). And then an increased level of public education on a local, national and global scale – to help minimise threats (esp. fin trade/habitat destruction e.g. various marine industries; development etc.). Perhaps consumer-driven pressure to make it unviable for stocking/sourcing of whale shark products? And then could it be possible to have a fisheries quota – and benefit the global conservation of this species? Discussions need to be had.

Between 1995 and 1997, 360 observations of whale sharks at Ningaloo Reef revealed that approximately 85% were males (4-12 m TL). Based on the external morphology of claspers, all males 9 m were considered mature. A logistic equation fitted to the percentage of mature males in each size class predicted a length at first maturity (L50) of ∼8.0 m TL, while 95% (L95) of males were mature by ∼9.0 m TL. Female whale sharks at Ningaloo Reef during this study were generally smaller and ranged in length from 4 to 8 m TL. The small size and general absence of female whale sharks from Ningaloo Reef suggest that the region may be important for feeding rather than breeding.

The formulation of conservation policy for species that are rare and migratory requires broad cooperation to ensure that adequate levels of standardized data collection are achieved and that the results of local analyses are comparable. Estimates of apparent survival rate, relative change in abundance, and proportions of newly marked and returning individuals can inform local management decisions while highlighting corresponding changes at other linked research stations. We have applied computer-assisted photo-identification and mark-recapture population modeling to whale sharks Rhincodon typus at Ningaloo Marine Park (NMP), Western Australia, to create a baseline trend for comparison with other regional aggregations of the species. We estimate several ecological parameters of interest, including an average apparent survival rate of 0.55 yr(-1) for sharks newly marked (new) and 0.83 yr(-1) for sharks captured in multiple seasons (philopatric). The average proportion of philopatric sharks is found to be 0.65 of the total population, and we derive an average population growth rate of 1.12 yr(-1) for them. Our analysis uncovered significant heterogeneity in capture and survival probabilities in this study population; our chosen model structures and data analysis account for these influences and demonstrate a good overall fit to the time-series data. The results show good correspondence between capture probability and an available measure of recapture effort, suggesting that unmodeled systematic effects contribute insignificantly to the model fits. We find no evidence of a decline in the whale shark population at NMP, and our results provide metrics of value to their future management. Overall, our study suggests an effective approach to analyzing and modeling mark-recapture data for a rare species using computer-assisted photo-identification and opportunistic data collection from ecotourism to ensure the quality and volume of data required for population analysis.

Whale sharks (Rhincodon typus) seasonally aggregate at Western Australia’s Ningaloo Reef in the austral autumn and winter, but their occurrence beyond this region during spring and summer remains elusive. The aggregation at Ningaloo Reef coincides with a pulse of productivity following mass coral spawning in early autumn, with the population during this period dominated by juveniles that amass for feeding purposes. To investigate their movement patterns beyond Ningaloo Reef, whale sharks were fitted with SPOT (n = 13) or SPLASH (n = 1) tags between April and September (2010–14). Tagged whale sharks ranged in total length from 3 to 9 m. Each whale shark was also photographed for its subsequent identification using Wildbook for Whale Sharks, and their years of residency at Ningaloo Reef determined. Temporal and spatial observations of whale shark sightings were also determined through the conducting of interviews with people throughout 14 coastal towns along the Western Australian coastline, as well as through historical sightings and the Wildbook database. Satellite tracking revealed that all sharks remained relatively close to the Western Australian coast, travelling a mean minimum distance of 1667 (±316, s.e.) km. Public reports, coupled with satellite tracking, demonstrated that whale sharks inhabit most of the Western Australian coast (from 35°S to 12°S), and that seasonal migrations beyond Ningaloo Reef may be to the north or south and may similarly be associated with areas of increased productivity.