First insights into the population characteristics and seasonal occurrence of the great hammerhead shark, Sphyrna mokarran (Rüppell, 1837) in the Western Tuamotu archipelago, French Polynesia

Frontiers in Marine Science

Marine Science

Yannis P. Papastamatiou¹  Johann Mourier²  Marc Hayek³  Jean-Marie Jeandel³  Tatiana Boube³  Enzo Laurent³  Alexander Mataarere³  Audrey Lenormand³  Claire-Sophie Azam³  Andréa Kunovsky³  Manuella Burlot³  Béatrice Rigoreau³  Nastazia Femmami³  Laurent Rigoreau³  Jordan Bouyeure³  Alice Bousseyroux³  Farid Chalabi³  Florent Bersani³  Virginie Jeandel³  Antonin Guilbert⁴  Thomas Pavy⁴  José E. Trujillo⁵  Thibaut Thellier⁶  Yann Follin⁶  Pierre-Louis Stenger⁷  Charlie Huveneers⁸ 

[1] Florida International University, Institute of Environment, Department of Biological Sciences, Miami, FL, United States;MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Sète, France;Mokarran Protection Society, BP 245 Avatoru, Rangiroa, French Polynesia;Mokarran Protection Society, BP 245 Avatoru, Rangiroa, French Polynesia;Andromède Océanologie, Mauguio, France;Mokarran Protection Society, BP 245 Avatoru, Rangiroa, French Polynesia;Department of Marine Science, University of Otago, Dunedin, New Zealand;Mokarran Protection Society, BP 245 Avatoru, Rangiroa, French Polynesia;Direction des Ressources Marines, Papeete, French Polynesia;Mokarran Protection Society, BP 245 Avatoru, Rangiroa, French Polynesia;New Caledonian Agronomic Institute, Campus Anse Vata IRD, Nouméa, New Caledonia;Southern Shark Ecology Group, College of Science and Engineering, Flinders University, Adelaide, SA, Australia;

关键词: Central Pacific;    photo-identification;    laser-photogrammetry;    sexual segregation;    seasonal residency;    site fidelity;    environmental drivers;   

DOI  :  10.3389/fmars.2023.1234059

 received in 2023-06-03, accepted in 2023-08-04,  发布年份 2023

来源: Frontiers

【 摘 要 】

The occurrence and seasonality of the Critically Endangered great hammerhead shark, Sphyrna mokarran, is data deficient in the Central Pacific region. Using photo-identification and laser-photogrammetry, we describe the seasonal population of great hammerhead sharks in the Tiputa pass (Rangiroa atoll) and Tuheiava pass (Tikehau atoll) in the Tuamotu archipelago of French Polynesia. During the austral summer of 2020 and 2021, we recorded a female-biased aggregation of at least 55 individuals (54 females; 1 unknown sex), representing an unprecedented number of S. mokarran in one study. All measured sharks were likely mature with pre-caudal lengths ranging from 147 cm to 297 cm (n = 35). Videos from citizen scientists recorded over a 15-year period enable us to identify 30 additional individuals between 2006 and 2019, with strong evidence of sexual segregation during the year. Our findings revealed seasonal residency (n = 32) of up to 6 days/month and for up to 5 months at the study site during the austral summer. We also demonstrated site fidelity with 32 individuals returning to the same atoll for up to 12 years between the first and last sighting, and with limited evidence of connectivity between the two sites. Our analysis also provides preliminary insight into the environmental factors driving S. mokarran aggregation in the Tiputa pass, suggesting a marked influence of the lunar cycle and of ocellated eagle rays (Aetobatus ocellatus) abundance. This study, conducted in situ with non-invasive methods offers a unique opportunity to study a great hammerhead shark population in a near-pristine ecosystem and provides important life-history elements for the Central Pacific region.

【 授权许可】

Unknown   
Copyright © 2023 Boube, Azam, Guilbert, Huveneers, Papastamatiou, Mourier, Trujillo, Femmami, Kunovsky, Bersani, Laurent, Bousseyroux, Thellier, Follin, Pavy, Jeandel, Mataarere, Burlot, Bouyeure, Rigoreau, Rigoreau, Lenormand, Chalabi, Hayek, Jeandel and Stenger