Post-nesting migrations of loggerhead sea turtles nesting in Japan-reference-data

Okuyama J, Watabe A, Takuma S, Tanaka K, Shirai K, Murakami-Sugihara N, Arita M, Fujita K, Nishizawa H, Narazaki T, Yamashita Y, Kameda K. 2022. Post-nesting migrations of loggerhead sea turtles nesting in Japan-reference-data. Movebank Data Repository. https://doi.org/10.5441/001/1.m3c90703/2

Abstract

Aim: Quantifying the importance of habitat areas for conservation of highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles (Caretta caretta) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify the proportions of turtles using these two contrasting habitats (foraging dichotomy) to suggest priority conservation areas. Location: North Pacific Ocean. Methods: We examined the occurrence of foraging dichotomy at three nesting sites (Ishigaki, Okinoerabu Islands and Ichinomiya) based on stable isotope analysis of the egg yolks for 82 turtles and satellite tracking of post-nesting migration for 12 turtles. Moreover, we used the data of three other sites from previous studies (Yakushima Island, Minabe and Omaezaki). Results: Two neritic foraging grounds (East China Sea and the coastal area of the Japanese archipelago), and an oceanic ground (North Pacific Ocean) were identified. We found a latitudinal cline with respect to the occurrence of foraging dichotomy; >84% of the females nesting at southern sites (Ishigaki and Okinoerabu Islands), 73% at middle sites (Yakushima Island and Minabe) and <46% at northern sites (Omaezaki and Ichinomiya) were neritic foragers; the proportion of oceanic foragers increased at northern sites. Based on the annual number of nests in the entire nesting region of Japan, satellite tracking and the latitudinal cline of foraging dichotomy, we estimated that 70% and 9% of annual nesting females in Japan utilize the neritic foraging habitat in the East China Sea and the coastal area of the Japanese archipelago, respectively, and that and 22% utilize the oceanic habitat of the North Pacific Ocean. Main conclusions: The East China Sea represents a critical foraging habitat for the North Pacific populations of endangered loggerhead sea turtles. Our findings emphasize the need for international management to ensure their protection.

Keywords

animal movement,animal tracking,Argos,Caretta caretta,conservation biology,loggerhead sea turtle,satellite telemetry

DOIs of related Publications

https://doi.org/10.1111/ddi.13531

URI

https://datarepository.movebank.org/handle/10255/move.1352

BibTex

@misc{001/1_m3c90703/2,
  title = {Post-nesting migrations of loggerhead sea turtles nesting in Japan-reference-data},
  author = {Okuyama, J and Watabe, A and Takuma, S and Tanaka, K and Shirai, K and Murakami-Sugihara, N and Arita, M and Fujita, K and Nishizawa, H and Narazaki, T and Yamashita, Y and Kameda, K},
  year = {2022},
  URL = {http://dx.doi.org/10.5441/001/1.m3c90703/2},
  doi = {doi:10.5441/001/1.m3c90703/2},
  publisher = {Movebank data repository}
}

RIS

TY  - DATA
ID  - doi:10.5441/001/1.m3c90703/2
T1  - Post-nesting migrations of loggerhead sea turtles nesting in Japan-reference-data
AU  - Okuyama, Junichi
AU  - Watabe, Akemi
AU  - Takuma, Shunichi
AU  - Tanaka, Kentaro
AU  - Shirai, Kotaro
AU  - Murakami-Sugihara, Naoko
AU  - Arita, Mamiko
AU  - Fujita, Kento
AU  - Nishizawa, Hideaki
AU  - Narazaki, Tomoko
AU  - Yamashita, Yoshiya
AU  - Kameda, Kazunari
Y1  - 2022/12/22
KW  - animal movement
KW  - animal tracking
KW  - Argos
KW  - Caretta caretta
KW  - conservation biology
KW  - loggerhead sea turtle
KW  - satellite telemetry
KW  - Caretta caretta
PB  - Movebank data repository
UR  - http://dx.doi.org/10.5441/001/1.m3c90703/2
DO  - doi:10.5441/001/1.m3c90703/2
ER  -

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