Stock composition of green turtles Chelonia mydas foraging in the Ryukyu Archipelago differs with size class

Natal Origin Identification of Green Turtles in the North Pacific by Genome-Wide Population Analysis With Limited DNA Samples

“…In addition, within Japanese nesting sites, the haplotype CmP39.1, CmP50.1, CmP53.1, CmP54.1, and CmP121.1 (and their shorter haplotypes) were widely detected in females nesting on the Ryukyus and in Ogasawara Islands ( Supplementary Table S3). Turtles with these seven mtDNA haplotypes are often captured in coastal set nets or stranded along the Ryukyus (Nishizawa et al, 2013;Hamabata et al, 2018). To explore whether the candidate natal region of foraging turtles with those haplotypes can be narrowed down, we included samples of foraging turtles with these widespread (n = 20) and common Japanese haplotypes (n = 36).…”

“…To explore whether the candidate natal region of foraging turtles with those haplotypes can be narrowed down, we included samples of foraging turtles with these widespread (n = 20) and common Japanese haplotypes (n = 36). These 56 samples were the same specimens used in the previous MSA study by Hamabata et al (2018).…”

“…To identify the mtDNA haplotypes of the newly collected samples, 820-bp fragments of the mtDNA control region were amplified by PCR and sequenced using an Applied Biosystems 3730xl DNA Analyzer using the primers LCM15382 and H950g (Abreu-Grobois et al, 2006) and the same procedure as described by Hamabata et al (2018). All sequences were confirmed to have been registered on GenBank by a nucleotide-nucleotide basic local alignment search tool (BLASTn) search on the NCBI website.…”

“…Like other marine megafauna, marine turtles have longevity, and thus it is difficult to track their movements during their lifetime. The data on identification of the natal origins of individuals in foraging sites are applied to estimate the patterns of developmental migration (Hamabata et al, 2018), and those on habitat connections are utilized to define the distinct population segments (DPS) for conservation and management (Seminoff et al, 2015).…”

“…In addition to rookery distribution, the coastal waters of the Ryukyus and the Japanese main islands provide foraging grounds for green turtles (Nishizawa et al, 2013(Nishizawa et al, , 2014Fukuoka et al, 2015Fukuoka et al, , 2019Hamabata et al, 2015;Kameda et al, 2017). Previous studies using MSA have revealed that the coasts of the Ryukyus provide foraging habitats to turtles from the southern tropical rookeries, such as islands in the Federated States of Micronesia (FSM), the Republic Marshall Islands (RMI), and Southeast Asia, as well as those from Japan (Nishizawa et al, 2013;Hamabata et al, 2018). However, the accuracy of MSA in the Western Pacific is low, because some haplotypes are often detected from multiple geographically remote nesting populations (called widespread haplotypes), impeding the identification of the origins of the turtles.…”