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Magson K, Monacella E, Scott C, Buffat N, Arunrugstichai S, Chuangcharoendee M, Pierce SJ, Holmberg J, Araujo G. Citizen science reveals the population structure and seasonal presence of whale sharks in the Gulf of Thailand. JOURNAL OF FISH BIOLOGY 2022; 101:540-549. [PMID: 35638311 DOI: 10.1111/jfb.15121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
The whale shark Rhincodon typus is a broadly distributed and highly mobile planktivorous shark species. The sharks form predictable aggregations in many areas, providing the opportunity for cost-effective scientific monitoring through divers and other marine resource users. Sightings of individuals outside of these aggregate zones elsewhere in their range are typically rare. We used a citizen science-based approach to shed light on occurrence and seasonality in the waters around Koh Tao, Thailand and neighbouring islands in the Gulf of Thailand. Although there is a paucity of quantitative data, anecdotal reports suggest substantial declines in sightings in the early 2000s. We identified a total of 178 individual whale sharks (from 249 sightings) between 2004 and 2019, with most of these (84%) from the 2015-2019 time period due to an increase in sighting reports facilitated by social media and direct marketing. Size estimates were reported for 102 of the sightings, with a range of 2-6 m and mean of 3.7 m overall. Sex was reported for 27% of sightings, with a 2:1 female-to-male ratio. Modified maximum likelihood methods suggest whale sharks are transient to Koh Tao and surrounding areas, with whale shark sightings following the regional monsoon cycle. One international resighting was obtained from Malaysian waters (~700 km away). Encouraging citizen science participation is particularly useful in data-poor regions like the Gulf of Thailand, despite limitations in size and sex estimation reliability, which can play an important complementary role in dedicated research programs.
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Affiliation(s)
- Kirsty Magson
- Thai Whale Sharks, Surat Thani, Thailand
- New Heaven Reef Conservation Program, Surat Thani, Thailand
- Conservation Diver, Evergreen, Colorado, USA
| | - Emily Monacella
- Thai Whale Sharks, Surat Thani, Thailand
- New Heaven Reef Conservation Program, Surat Thani, Thailand
| | - Chad Scott
- Conservation Diver, Evergreen, Colorado, USA
| | - Noémie Buffat
- Thai Whale Sharks, Surat Thani, Thailand
- New Heaven Reef Conservation Program, Surat Thani, Thailand
| | | | | | | | | | - Gonzalo Araujo
- Marine Research and Conservation Foundation, Somerset, UK
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Hardenstine RS, He S, Cochran JEM, Braun CD, Cagua EF, Pierce SJ, Prebble CEM, Rohner CA, Saenz‐Angudelo P, Sinclair‐Taylor TH, Skomal GB, Thorrold SR, Watts AM, Zakroff CJ, Berumen ML. Pieces in a global puzzle: Population genetics at two whale shark aggregations in the western Indian Ocean. Ecol Evol 2022; 12:e8492. [PMID: 35127024 PMCID: PMC8796955 DOI: 10.1002/ece3.8492] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 10/30/2021] [Accepted: 11/10/2021] [Indexed: 02/01/2023] Open
Abstract
The whale shark Rhincodon typus is found throughout the world's tropical and warm-temperate ocean basins. Despite their broad physical distribution, research on the species has been concentrated at a few aggregation sites. Comparing DNA sequences from sharks at different sites can provide a demographically neutral understanding of the whale shark's global ecology. Here, we created genetic profiles for 84 whale sharks from the Saudi Arabian Red Sea and 72 individuals from the coast of Tanzania using a combination of microsatellite and mitochondrial sequences. These two sites, separated by approximately 4500 km (shortest over-water distance), exhibit markedly different population demographics and behavioral ecologies. Eleven microsatellite DNA markers revealed that the two aggregation sites have similar levels of allelic richness and appear to be derived from the same source population. We sequenced the mitochondrial control region to produce multiple global haplotype networks (based on different alignment methodologies) that were broadly similar to each other in terms of population structure but suggested different demographic histories. Data from both microsatellite and mitochondrial markers demonstrated the stability of genetic diversity within the Saudi Arabian aggregation site throughout the sampling period. These results contrast previously measured declines in diversity at Ningaloo Reef, Western Australia. Mapping the geographic distribution of whale shark lineages provides insight into the species' connectivity and can be used to direct management efforts at both local and global scales. Similarly, understanding historical fluctuations in whale shark abundance provides a baseline by which to assess current trends. Continued development of new sequencing methods and the incorporation of genomic data could lead to considerable advances in the scientific understanding of whale shark population ecology and corresponding improvements to conservation policy.
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Affiliation(s)
- Royale S. Hardenstine
- Division of Biological and Environmental Science and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Song He
- Division of Biological and Environmental Science and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Jesse E. M. Cochran
- Division of Biological and Environmental Science and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Camrin D. Braun
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Edgar Fernando Cagua
- School of Biological SciencesCentre for Integrative EcologyUniversity of CanterburyChristchurchNew Zealand
- WorldFishBayan LepasMalaysia
| | | | - Clare E. M. Prebble
- Marine Megafauna FoundationTruckeeCaliforniaUSA
- National Oceanography CentreUniversity of South HamptonSouth HamtonUK
| | | | - Pablo Saenz‐Angudelo
- Facultad de CienciasInstituo de Ciencias Ambientales y EvolutivasUniversidad Austral de ChileValdiviaChile
| | | | - Gregory B. Skomal
- Massachusetts Division of Marine FisheriesNew BedfordMassachusettsUSA
| | - Simon R. Thorrold
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Alexandra M. Watts
- Marine Megafauna FoundationTruckeeCaliforniaUSA
- Ecological Genetics and Conservation LaboratoryManchester Metropolitan UniversityManchesterUK
| | - Casey J. Zakroff
- Division of Biological and Environmental Science and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Michael L. Berumen
- Division of Biological and Environmental Science and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
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Guillaume MMM, Séret B. Observations of sharks (Elasmobranchii) at Europa Island, a remote marine protected area important for shark conservation in the southern Mozambique Channel. PLoS One 2021; 16:e0253867. [PMID: 34610033 PMCID: PMC8491881 DOI: 10.1371/journal.pone.0253867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 06/15/2021] [Indexed: 11/19/2022] Open
Abstract
Sharks have declined worldwide and remote sanctuaries are becoming crucial for shark conservation. The southwest Indian Ocean is a hotspot of both terrestrial and marine biodiversity mostly impacted by anthropogenic damage. Sharks were observed during surveys performed from April to June 2013 in the virtually pristine coral reefs around Europa Island, a remote Marine Protected Area located in the southern Mozambique Channel. Observation events comprised 67 1-hour scientific dives between 5 – 35m depth and 7 snorkeling inspections, as well as 4 dinghy-based observations in the shallow lagoon. In a period of 24 days, 475 sharks were tallied. Carcharhinus galapagensis was most encountered and contributed 20% of the abundance during diving, followed by C. albimarginatus (10%). Both species were more abundant between 11-14h, and on the exposed sides of the island. Numbers of Sphyrna lewini were highest with 370 individuals windward and leeward, mostly schooling. S. lewini aggregations in the area are hypothesized to be attracted to the seamount archipelago offering favorable conditions for deep incursions and of which Europa Island forms part. C. amblyrhynchos, Galeocerdo cuvier and S. mokarran were uncommon, while there was an additional observation of Rhincodon typus. The lagoon of Europa was a nursery ground for C. melanopterus where it was the only species present. A total of 8 species was recorded, contributing to the shark diversity of 15 species reported from Europa since 1952 in the scientific and gray literature. Overall, with the occurrence of several species of apex predators in addition to that of R. typus, large schools of S. lewini, fair numbers of reef sharks and a nursery of C. melanopterus, Europa’s sharks constitute a significant reservoir of biodiversity, which contributes to preserve the functioning of the ecosystem. Our observations highlight the relevance of Europa Island for shark conservation and the need for shark-targeted management in the EEZ of both Europa and Bassas da India.
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Affiliation(s)
- Mireille M. M. Guillaume
- Laboratoire BOrEA MNHN-SU-CNRS-IRD-UCN-UA EcoFunc, Aviv, Muséum National d’Histoire Naturelle, Paris, France
- Laboratoire d’Excellence CORAIL, Perpignan, France
- * E-mail:
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Andrzejaczek S, Vély M, Jouannet D, Rowat D, Fossette S. Regional movements of satellite-tagged whale sharks Rhincodon typus in the Gulf of Aden. Ecol Evol 2021; 11:4920-4934. [PMID: 33976859 PMCID: PMC8093710 DOI: 10.1002/ece3.7400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 11/06/2022] Open
Abstract
To gain insight into whale shark (Rhincodon typus) movement patterns in the Western Indian Ocean, we deployed eight pop-up satellite tags at an aggregation site in the Arta Bay region of the Gulf of Tadjoura, Djibouti in the winter months of 2012, 2016, and 2017. Tags revealed movements ranging from local-scale around the Djibouti aggregation site, regional movements along the coastline of Somaliland, movements north into the Red Sea, and a large-scale (>1,000 km) movement to the east coast of Somalia, outside of the Gulf of Aden. Vertical movement data revealed high occupation of the top ten meters of the water column, diel vertical movement patterns, and deep diving behavior. Long-distance movements recorded both here and in previous studies suggest that connectivity between the whale sharks tagged at the Djibouti aggregation and other documented aggregations in the region are likely within annual timeframes. In addition, wide-ranging movements through multiple nations, as well as the high use of surface waters recorded, likely exposes whale sharks in this region to several anthropogenic threats, including targeted and bycatch fisheries and ship-strikes. Area-based management approaches focusing on seasonal hotspots offer a way forward in the conservation of whale sharks in the Western Indian Ocean.
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Affiliation(s)
| | | | | | - David Rowat
- Marine Conservation Society SeychellesMaheSeychelles
| | - Sabrina Fossette
- MegapteraParisFrance
- Biodiversity and Conservation ScienceDepartment of Biodiversity, Conservation and AttractionsKensingtonWAAustralia
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Callaghan CT, Poore AGB, Mesaglio T, Moles AT, Nakagawa S, Roberts C, Rowley JJL, VergÉs A, Wilshire JH, Cornwell WK. Three Frontiers for the Future of Biodiversity Research Using Citizen Science Data. Bioscience 2020. [DOI: 10.1093/biosci/biaa131] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AbstractCitizen science is fundamentally shifting the future of biodiversity research. But although citizen science observations are contributing an increasingly large proportion of biodiversity data, they only feature in a relatively small percentage of research papers on biodiversity. We provide our perspective on three frontiers of citizen science research, areas that we feel to date have had minimal scientific exploration but that we believe deserve greater attention as they present substantial opportunities for the future of biodiversity research: sampling the undersampled, capitalizing on citizen science's unique ability to sample poorly sampled taxa and regions of the world, reducing taxonomic and spatial biases in global biodiversity data sets; estimating abundance and density in space and time, develop techniques to derive taxon-specific densities from presence or absence and presence-only data; and capitalizing on secondary data collection, moving beyond data on the occurrence of single species and gain further understanding of ecological interactions among species or habitats. The contribution of citizen science to understanding the important biodiversity questions of our time should be more fully realized.
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Affiliation(s)
- Corey T Callaghan
- Centre for Ecosystem Science, School of Biological, Earth, and Environmental Sciences, University of New South Wales
- Ecology and Evolution Research Centre, School of Biological, Earth, and Environmental Sciences, also at the University of New South Wales
| | - Alistair G B Poore
- Ecology and Evolution Research Centre, School of Biological, Earth, and Environmental Sciences, also at the University of New South Wales
| | - Thomas Mesaglio
- Centre for Ecosystem Science, School of Biological, Earth, and Environmental Sciences, University of New South Wales
| | - Angela T Moles
- Ecology and Evolution Research Centre, School of Biological, Earth, and Environmental Sciences, also at the University of New South Wales
| | - Shinichi Nakagawa
- Ecology and Evolution Research Centre, School of Biological, Earth, and Environmental Sciences, also at the University of New South Wales
| | - Christopher Roberts
- Centre for Ecosystem Science, School of Biological, Earth, and Environmental Sciences, University of New South Wales
| | - Jodi J L Rowley
- Australian Museum Research Institute, part of the Australian Museum, Sydney, New South Wales, Australia
| | - Adriana VergÉs
- Ecology and Evolution Research Centre, School of Biological, Earth, and Environmental Sciences, also at the University of New South Wales
| | - John H Wilshire
- Centre for Ecosystem Science, School of Biological, Earth, and Environmental Sciences, University of New South Wales
| | - William K Cornwell
- Centre for Ecosystem Science, School of Biological, Earth, and Environmental Sciences, University of New South Wales
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Changes in diving behaviour and habitat use of provisioned whale sharks: implications for management. Sci Rep 2020; 10:16951. [PMID: 33046780 PMCID: PMC7550605 DOI: 10.1038/s41598-020-73416-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 09/15/2020] [Indexed: 12/14/2022] Open
Abstract
Whale shark (Rhincodon typus) tourism is increasingly popular at predictable aggregations around the world, but only a few use provisioning to ensure close interactions. Understanding the effects of provisioning on the behaviour of this endangered species is critical to manage this growing industry. We recorded the diving behaviour and habitat use of juvenile whale sharks (n = 4) for a mean of 49.5 provisioned and 33.8 non-provisioned days using temperature-depth-recorders. We found that time spent at the surface (< 2 m) between 6 am and 1 pm increased ~ sixfold, while timing of deep dives shifted from 4–10 am to 10 am–2 pm, i.e. near or at the end of the provisioning activities. The shift might be related to a need to thermoregulate following a prolonged period of time in warmer water. These changes could have fitness implications for individuals frequently visiting the provisioning site. Based on recorded amount of time spent in warm waters and published Q10 values for ectotherms, we estimate a 7.2 ± 3.7% (range 1.3–17.8%) higher metabolic rate when sharks frequent the provisioning site. The observed behavioural, habitat use, and potential fitness shifts should be considered when developing guidelines for sustainable tourism, particularly in light of new provisioning sites developing elsewhere.
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Araujo G, Agustines A, Tracey B, Snow S, Labaja J, Ponzo A. Photo-ID and telemetry highlight a global whale shark hotspot in Palawan, Philippines. Sci Rep 2019; 9:17209. [PMID: 31748588 PMCID: PMC6868279 DOI: 10.1038/s41598-019-53718-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/05/2019] [Indexed: 02/07/2023] Open
Abstract
The Philippines is home to the second largest known population of whale sharks in the world. The species is listed as endangered due to continued population declines in the Indo-Pacific. Knowledge about the connectivity within Southeast Asia remains poor, and thus international management is difficult. Here, we employed pop-up archival tags, data mining and dedicated effort to understand an aggregation of whale sharks at Honda Bay, Palawan, Philippines, and its role in the species' conservation. Between Apr and Oct 2018, we conducted 159 surveys identifying 117 individual whale sharks through their unique spot patterns (96.5% male, mean 4.5 m). A further 66 individual whale sharks were identified from local operators, and data mined on social media platforms. The satellite telemetry data showed that the whale sharks moved broadly, with one individual moving to Sabah, Malaysia, before returning to the site <1 year later. Similarly, another tagged whale shark returned to the site at a similar periodicity after reaching the Malay-Filipino border. One individual whale shark first identified in East Kalimantan, Indonesia by a citizen scientist was resighted in Honda Bay ~3.5 years later. Honda Bay is a globally important site for the endangered whale shark with connectivity to two neighbouring countries, highlighting the need for international cooperation to manage the species.
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Affiliation(s)
- Gonzalo Araujo
- Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Jagna, 6308, Bohol, Philippines.
| | - Ariana Agustines
- Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Jagna, 6308, Bohol, Philippines
| | - Brian Tracey
- Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Jagna, 6308, Bohol, Philippines
| | - Sally Snow
- Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Jagna, 6308, Bohol, Philippines
| | - Jessica Labaja
- Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Jagna, 6308, Bohol, Philippines
| | - Alessandro Ponzo
- Large Marine Vertebrates Research Institute Philippines, Cagulada Compound, Jagna, 6308, Bohol, Philippines
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Cochran JEM, Braun CD, Cagua EF, Campbell MF, Hardenstine RS, Kattan A, Priest MA, Sinclair-Taylor TH, Skomal GB, Sultan S, Sun L, Thorrold SR, Berumen ML. Multi-method assessment of whale shark (Rhincodon typus) residency, distribution, and dispersal behavior at an aggregation site in the Red Sea. PLoS One 2019; 14:e0222285. [PMID: 31498848 PMCID: PMC6733483 DOI: 10.1371/journal.pone.0222285] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 08/25/2019] [Indexed: 11/29/2022] Open
Abstract
Whale sharks (Rhincodon typus) are typically dispersed throughout their circumtropical range, but the species is also known to aggregate in specific coastal areas. Accurate site descriptions associated with these aggregations are essential for the conservation of R. typus, an Endangered species. Although aggregations have become valuable hubs for research, most site descriptions rely heavily on sightings data. In the present study, visual census, passive acoustic monitoring, and long range satellite telemetry were combined to track the movements of R. typus from Shib Habil, a reef-associated aggregation site in the Red Sea. An array of 63 receiver stations was used to record the presence of 84 acoustically tagged sharks (35 females, 37 males, 12 undetermined) from April 2010 to May 2016. Over the same period, identification photos were taken for 76 of these tagged individuals and 38 were fitted with satellite transmitters. In total of 37,461 acoustic detections, 210 visual encounters, and 33 satellite tracks were analyzed to describe the sharks’ movement ecology. The results demonstrate that the aggregation is seasonal, mostly concentrated on the exposed side of Shib Habil, and seems to attract sharks of both sexes in roughly equal numbers. The combined methodologies also tracked 15 interannual homing-migrations, demonstrating that many sharks leave the area before returning in later years. When compared to acoustic studies from other aggregations, these results demonstrate that R. typus exhibits diverse, site-specific ecologies across its range. Sightings-independent data from acoustic telemetry and other sources are an effective means of validating more common visual surveys.
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Affiliation(s)
- Jesse E. M. Cochran
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- * E-mail:
| | - Camrin D. Braun
- Massachusetts Institute of Technology–Woods Hole Oceanographic Institution Joint Program in Oceanography/Applied Ocean Science and Engineering, Cambridge, MA, United States of America
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - E. Fernando Cagua
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag, Christchurch, New Zealand
| | - Michael F. Campbell
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Royale S. Hardenstine
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Alexander Kattan
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Mark A. Priest
- Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, St. Lucia, Queensland, Australia
| | - Tane H. Sinclair-Taylor
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Gregory B. Skomal
- Massachusetts Division of Marine Fisheries, New Bedford, MA, United States of America
| | - Sahar Sultan
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- School of Biology, University of St Andrews, St Andrews, Scotland, United Kingdom
| | - Lu Sun
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
- Key Laboratory of Science and Engineering for Marine Ecology and Environment, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, China
| | - Simon R. Thorrold
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Michael L. Berumen
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
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