Undersea Constellations: The Global Biology of an Endangered Marine Megavertebrate Further Informed through Citizen Science

Norman, Brad; Holmberg, Jason; Arzoumanian, Zaven; Reynolds, Samantha; Wilson, Rory P.; Rob, Dani; Pierce, Simon J.; Gleiss, Adrian C.; Parra, Rafael de la; Galvan, Beatriz Eugenia; Ramírez‐Macías, Dení; Robinson, David P.; Fox, Steve; Graham, Rachel T.; Rowat, David; Potenski, Matthew D.; Levine, Marie; McKinney, Jennifer A.; Hoffmayer, Eric R.; Dove, Alistair D. M.; Hueter, Robert E.; Ponzo, Alessandro; Araújo, Gonzalo; Aca, Elson; David, David; Rees, Richard; Duncan, Alan; Rohner, Christoph A.; Prebble, Clare E. M.; Hearn, Alex; Acuna, David; Berumen, Michael L.; Vázquez, Abraham; Green, Jonathan; Bach, Steffen; Schmidt, Jennifer V.; Beatty, S.J.; Morgan, David L.

doi:10.1093/biosci/bix127

Cited by 63 publications

(94 citation statements)

References 75 publications

(82 reference statements)

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“…Alternatively, the lack of mixing could indicate size/age segregation within the Philippines, which would be essential information for managing critical habitats for the species (e.g., foraging, developmental, migratory corridors). A recent global photo-ID study across multiple sites revealed little movement between aggregations (Norman et al, 2017), as did a separate study looking at multiple sites in the Indian Ocean where only 1 whale shark out of 1,724 was sighted between two countries (Andrzejaczek et al, 2016). Telemetry tracking studies might help elucidate the movement patterns and connectivity of whale sharks in the Philippines.…”

Section: Discussionmentioning

confidence: 95%

“…Whale sharks have unique spot patterns on their bodies that allow for minimally invasive mark-recapture studies through photo-ID (Arzoumanian et al, 2005). It is an effective research technique for population demographics, and has been successfully employed in all sites at which they aggregate (Norman et al, 2017). Given the slow, surface-dwelling nature of the whale shark, photos of individuals captured by tourists has made citizen science contributions an active part of their research and conservation (e.g., Araujo et al, 2016;Norman et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…It is an effective research technique for population demographics, and has been successfully employed in all sites at which they aggregate (Norman et al, 2017). Given the slow, surface-dwelling nature of the whale shark, photos of individuals captured by tourists has made citizen science contributions an active part of their research and conservation (e.g., Araujo et al, 2016;Norman et al, 2017). The use of an online-based tool, Wildbook for Whale Sharks (www.whaleshark.org), enables the comparison of identification data on a global scale.…”

Section: Introductionmentioning

confidence: 99%

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Long-Term Photo-Identification Reveals the Population Dynamics and Strong Site Fidelity of Adult Whale Sharks to the Coastal Waters of Donsol, Philippines

McCoy

Burce²,

David³

et al. 2018

Front. Mar. Sci.

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Donsol in the Philippines is the longest running community-based whale shark (Rhincodon typus) ecotourism site in Southeast Asia, with peak visitation in 2012 of over 27,000 tourists. In order to understand this aggregation and the importance of the area to whale sharks, dedicated photographic identification (photo-ID) research began in 2007. In-water photo-ID surveys were conducted from tourism boats, weather and operator permitting, from December to June between 2007 and 2016. Visual matches of the unique spot patterns of each individual shark were validated by the pattern-recognition software Interactive Individual Identification System (I 3 S), and on the online database Wildbook for Whale Sharks (www.whaleshark.org). A total of 1,985 photo-ID trips over 895 survey days resulted in 6,786 encounters with R. typus. Combined with encounters from both dedicated research and citizen science dating back to 1998, 479 individual whale sharks were identified, making up 44% of the known whale shark population in the Philippines (n = 1,095). Of these, photographs of the pelvic region confirmed the sex for 158 males and 22 females. Visual size estimates ranged from 2 to 10 m (mean ± SD = 6.5 ± 1.6 m). Maturity in males (LT 50 ) was estimated at 6.8 ± 0.2 m total length, with 53% of males considered mature. Annually, the total number of individuals sighted varied between 15 and 185 (mean ± SD = 104 ± 55.53), with a recruitment of 3-90 new individuals yearly (mean ± SD = 46.8 ± 36.29). Modeled residency using maximum likelihood methods suggested whale sharks spent 49.8 ± S.E. 14.5 [95% CI (32.3-78.6)] days in Donsol each season, with 47.1-60.8 whale sharks at any one time during the season. Twenty individuals were recorded through photo-ID at other sites across the Philippines. The extended residency of whale sharks at Donsol, paired with the presence of sexually mature animals and the economic value of the tourism industry, highlights the importance of Donsol for this endangered species.

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Section: Discussionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Long-Term Photo-Identification Reveals the Population Dynamics and Strong Site Fidelity of Adult Whale Sharks to the Coastal Waters of Donsol, Philippines

McCoy

Burce²,

David³

et al. 2018

Front. Mar. Sci.

Self Cite

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“…Photo-ID has been successfully employed to engage the general public in monitoring of marine animal populations (e.g. whale sharks; Norman et al 2017), although the implications of doing so are seldomly discussed. For turtles, in-water behavioural observations are limited and thus the design of accurate guidelines is not yet possible, although precautionary measures based on existing data are recommended (Griffin et al 2017).…”

Section: Discussionmentioning

confidence: 99%

In-water methods reveal population dynamics of a green turtle Chelonia mydas foraging aggregation in the Philippines

Araújo¹,

Legaspi²,

Ferber³

et al. 2019

Endang. Species. Res.

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The green turtle Chelonia mydas is an Endangered species that forms aggregations at neritic foraging sites where juveniles spend, in some cases, over a decade before moving to adult-or subadult-dominated foraging sites. Here, we used photographic identification, behavioural observations, paired-laser and stereo-photogrammetry to determine the population dynamics of a coastal aggregation of green turtles in Oslob, Philippines. We identified a total of 82 individual turtles between May 2012 and October 2018. We recorded behavioural observations during individual identification and found that turtles changed behaviour in 25% of instances. Some turtles were identified consistently throughout the study period, indicating strong site fidelity and residency. Modified maximum likelihood models suggest turtles spend the majority of their time within the study area (> 92%), although some (8%) excursions outside the area do occur. Markrecapture models suggest this foraging aggregation exhibits a pattern similar to that of a closed population. This is likely due to the extended residency periods of some individuals at the site, and the relatively low recruitment rate over time. We measured 18 turtles using paired-laser photogrammetry, with estimated straight carapace length of 55.3 cm, and mean growth rates of 3.4 cm yr −1 . Stereo-photogrammetry measurements were consistent and more accurate than visual or paired-laser photogrammetry estimates. Our results highlight the use of in-water methods to understand population dynamics of green turtles, and the importance of coastal, juvenile-dominated habitats for green turtles, as well as the need for effective conservation and management strategies to safeguard them.

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“…copepods, Motta et al, 2010;sergestids, Rohner et al, 2015;coral spawn, Holmberg et al, 2008). Most coastal aggregations are dominated by juvenile male sharks (Norman et al, 2017), although Cochran et al (2016) reported the first known juvenile 1:1 male to female aggregation in the Red Sea. Recent observations from the Galapagos, Qatar, St Helena and Baja California (Hearn et al, 2016;Robinson et al, 2017;Clingham et al, 2016;Ramirez-Macias et al, 2017) have highlighted that adult sharks are likely to have more pelagic habitat preferences than juveniles.…”

Section: Introductionmentioning

confidence: 99%

Peer Review #1 of "Satellite tracking of juvenile whale sharks in the Sulu and Bohol Seas, Philippines (v0.1)"

2018

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The whale shark Rhincodon typus was uplisted to 'Endangered' in the 2016 IUCN Red List due to >50% population decline, largely caused by continued exploitation in the Indo-Pacific. Though the Philippines protected the whale shark in 1998, concerns remain due to continued take in regional waters. In light of this, understanding the movements of whale sharks in the Philippines, one of the most important hotspots for the species, is vital. We tagged 17 juvenile whale sharks with towed SPOT5 tags from three general areas in the Sulu and Bohol Seas: Panaon Island in Southern Leyte, northern Mindanao, and Tubbataha Reefs Natural Park (TRNP). The sharks all remained in Philippine waters for the duration of tracking (6-126 days, mean 64). Individuals travelled 86-2,580 km (mean 887 km) at a mean horizontal speed of 15.5 ± 13.0 SD km day-1. Whale sharks tagged in Panaon Island and Mindanao remained close to shore but still spent significant time off the shelf (>200 m). Sharks tagged at TRNP spent most of their time offshore in the Sulu Sea. Three of twelve whale sharks tagged in the Bohol Sea moved through to the Sulu Sea, whilst two others moved east through the Surigao Strait to the eastern coast of Leyte. One individual tagged at TRNP moved to northern Palawan, and subsequently to the eastern coast of Mindanao in the Pacific Ocean. Based on inferred relationships with temperature histograms, whale sharks performed most deep dives (>200 m) during the night, in contrast to results from whale sharks elsewhere. While all sharks stayed in national waters, our results highlight the high mobility of juvenile whale sharks and demonstrate their connectivity across the Sulu and Bohol Seas, highlighting the importance of the area for this endangered species.

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Undersea Constellations: The Global Biology of an Endangered Marine Megavertebrate Further Informed through Citizen Science

Cited by 63 publications

References 75 publications

Long-Term Photo-Identification Reveals the Population Dynamics and Strong Site Fidelity of Adult Whale Sharks to the Coastal Waters of Donsol, Philippines

Long-Term Photo-Identification Reveals the Population Dynamics and Strong Site Fidelity of Adult Whale Sharks to the Coastal Waters of Donsol, Philippines

In-water methods reveal population dynamics of a green turtle Chelonia mydas foraging aggregation in the Philippines

Peer Review #1 of "Satellite tracking of juvenile whale sharks in the Sulu and Bohol Seas, Philippines (v0.1)"

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