Spatio-temporal patterns of mitochondrial DNA variation in hawksbill turtles (Eretmochelys imbricata) in Southeast Asia Hideaki Nishizawa a , Juanita Joseph b, ⁎, Yee Kuen Chong b a Graduate School of Informatics, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan b Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia abstract article info Article history: Received 1 June 2015 Received in revised form 23 October 2015 Accepted 24 October 2015 Available online 31 October 2015 Keywords: Haplotype Malaysia Natal philopatry Polymorphism Rookery Sea turtle Mitochondrial DNA (mtDNA) polymorphisms provide useful information that can be used to estimate the phylogeographic relationships, historical demography, and migratory events of widely distributed animals. In this study, the spatio-temporal patterns of mtDNA polymorphisms were assessed in Indo-Pacific hawksbill turtles from Malaysian nesting rookeries and foraging aggregations sampled during 1996–2014. Clear genetic differences were observed between turtles from the Sabah Turtle Islands rookery in the Sulu Sea, and the rookeries of Melaka and Redang Island in the South China Sea off the Malay Peninsula; however, no temporal genetic changes were found to have occurred on a decadal time scale. Despite the descriptive evalua- tion of a few samples, Johor nesting turtles possessed different haplotypes from those at the proximate Melaka rookery, indicating the importance of conserving this small nesting population. Although continuous sampling efforts are needed to determine the relationships between specific rookeries and foraging aggregations, the presence of multiple haplotypes in Malaysian foraging aggregations, in combination with Lagrangian drifter buoy data, suggests that there have been migrations to foraging grounds in Southeast Asia from various rookeries. This study provides basic information for the conservation and management of hawksbill turtles in Southeast Asia. © 2015 Elsevier B.V. All rights reserved. 1. Introduction The hawksbill turtle [Eretmochelys imbricata (L.)] is a marine reptile globally distributed in tropical areas including Southeast Asia. Because of the exploitation of shells used in the bekko industry and eggs for food, in addition to bycatch, and the loss of nesting and foraging grounds, the number of hawksbill turtles has declined globally (Meylan and Donnelly, 1999). As a result, the hawksbill turtle is listed as Critically Endangered on the International Union for Conservation of Nature (IUCN) Red List (IUCN, 2014). Southeast Asian hawksbill tur- tles are no exception and populations have declined (Shanker and Pilcher, 2003). Egg collection is one of the major threats to hawksbill turtles in Southeast Asian rookeries (Chan, 2006; Shanker and Pilcher, 2003); however, legislation banning or regulating the commercial sale of hawksbill turtle eggs is insufficient. For example, in Malaysia there are legislations in the sates of Sabah and Sarawak, but not in Peninsular Malaysia (WWF—Malaysia, 2009). As a result, conservation efforts, in- cluding the establishment of sanctuaries at nesting sites in Southeast Asia, have recently commenced (Chan, 2006, 2010). To provide an important basis for conservation and management, it is necessary to investigate migration patterns and population genetic structures of hawksbill turtles. Due to the relatively wide distribution and abundance of rookeries (i.e., nesting grounds), studies of sea turtles have primarily focused on species such as green turtles [Chelonia mydas (L.)] and loggerhead turtles [Caretta caretta (L.)] (e.g., Boyle et al., 2009; Dethmers et al., 2006; Encalada et al., 1996, 1998; Hatase et al., 2002; Nishizawa et al., 2013; Shamblin et al., 2014). Hawksbill turtles have been studied mainly in the Caribbean and Atlantic, and previous studies demonstrated the genetic differentiation among hawksbill tur- tles in rookeries that reflects natal philopatry (Bass et al., 1996; Monzón-Argüello et al., 2010a), contemporary migration from rooker- ies to foraging grounds (Blumenthal et al., 2009; Bowen et al., 2007; Monzón-Argüello et al., 2011; Vilaça et al., 2013), and phylogeography (LeRoux et al., 2012). However, there have been only a few studies on Southeast Asian hawksbill turtles; therefore, filling these geographic and interspecific gaps in knowledge is required. Mitochondrial DNA (mtDNA) haplotypes of Indo-Pacific hawksbill turtle foraging aggregations in the western Pacific indicates the pres- ence of multiple clades (Nishizawa et al., 2010; Okayama et al., 1999), and the recently reported haplotypes found in nesting hawksbill turtle populations in Southeast Asia supports the existence of distinct clades (Wahidah and Syed Abdullah, 2009). However, the limited number of Journal of Experimental Marine Biology and Ecology 474 (2016) 164–170 ⁎ Corresponding author. E-mail address: juanita@umt.edu.my (J. Joseph). http://dx.doi.org/10.1016/j.jembe.2015.10.015 0022-0981/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Journal of Experimental Marine Biology and Ecology journal homepage: www.elsevier.com/locate/jembe