title: Population structure of a whale shark Rhincodon typus aggregation in the Red Sea.
abstract: The presence of whale sharks Rhincodon typus were recorded around Shib Habil, a small, coastal reef off the Red Sea coast of Saudi Arabia, from 2010 to 2015. A total of 267 suitable photographs resulting in the identification of 136 individuals, were documented from 305 encounters. Sharks were divided evenly between the sexes with no evidence of temporal or spatial segregation. All individuals were immature based on size estimates and, for males, juvenile clasper morphology. Scars were reported for 57% of R. typus with 15% showing evidence of propeller trauma. Estimates of population size and patterns of residency were calculated by modelling the lagged identification rate. Multiple models were run simultaneously and compared using the Akaike information criterion. An open population model was found to best represent the data and estimates a daily abundance between 15 and 34 R. typus during the aggregation season, with local residence times ranging from 4 to 44 days. Residence times away from Shib Habil range from 15 to 156 days with a permanent emigration-death rate between 0·07 and 0·58 individuals year(-1) . These results are broadly similar to those from other aggregations of R. typus, although the observed sexual parity and integration found at this site is unique for the species and needs further study.
authors.affiliation: Red Sea Research Centre, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia.
authors.forename: J E M
authors.initials: JE
authors.lastname: Cochran
authors.affiliation: Red Sea Research Centre, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia.
authors.forename: R S
authors.initials: RS
authors.lastname: Hardenstine
authors.affiliation: MIT-WHOI Joint Program in Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA, 02540, U.S.A.
authors.forename: C D
authors.initials: CD
authors.lastname: Braun
authors.affiliation: Massachusetts Division of Marine Fisheries, New Bedford, MA, U.S.A.
authors.forename: G B
authors.initials: GB
authors.lastname: Skomal
authors.affiliation: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, U.S.A.
authors.forename: S R
authors.initials: SR
authors.lastname: Thorrold
authors.affiliation: Department of Management Science, University of Miami, Miami, FL, 33124, U.S.A.
authors.forename: K
authors.initials: K
authors.lastname: Xu
authors.affiliation: CEMSE Division, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia.
authors.forename: M G
authors.initials: MG
authors.lastname: Genton
authors.affiliation: Red Sea Research Centre, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Kingdom of Saudi Arabia.
authors.forename: M L
authors.initials: ML
authors.lastname: Berumen
mesh_terms: D000818:Animals; D017753:Ecosystem; D005260:Female; D019156:Indian Ocean; D008297:Male; D011156:Population Density; D011157:Population Dynamics; D012529:Saudi Arabia; D012621:Seasons; D012754:Sharks
keywords: 13S; Saudi Arabia; interactive individual identification system; lagged identification rate; photo-identification; population modelling