Pic Dr. Hideaki Nishizawa

INOS is having a visiting scholar from University Kyoto, Dr. Hideaki Nishizawa from 20 May – 8 June 2015. He is also the research collaborator for the INOS Turtle Group.

27 May 2015 (Wednesday)

3.00pm.

Venue: Auditorium INOS.

Presentation title: Migration and habitat shift of green turtles in Japan: Insights through multiple approaches.

ABSTRACT

In Japan, there are mainlythree species of sea turtles, loggerhead turtle (Carettacaretta), green turtle (Cheloniamydas), and hawksbill turtle (Eretmochelysimbricata). Most popular species is loggerhead turtle that has been intensively researchedin the north Pacific in previous studies. On the other hand, secondly popular green turtle has less been investigated, although there are some nesting rookeries and foraging grounds of this endangered species. Understanding sea turtle behavior and migration is a big challenge because of cryptic migratory features. When they enter the sea, it is difficult to track and observe them directly. Therefore, it is necessary to integrate information about sea turtles via multiple approaches, using genetics, size data, morphological data, and telemetry and bio-logging data. I introduce some studies of Japanese green turtles investigated with my collaborators: 1)natal philopatry and linkage between foraging grounds and rookeries estimated by DNA haplotypes, 2) habitat shift from oceanic to neritic habitat and flexibility of foraging habitat use indicated by body size distribution and morphology, and3) post-nesting migration and inter-nesting behaviors indicated by telemetry and bio-logging techniques.

 

 

Abstract

While the sinking formation of Antarctic Bottom Water (AABW) is well understood, how this bottom water "returns home" through upwelling within ocean basins, particularly the Indo-Pacific, remains shrouded in uncertainty. In the 1960s, Munk’s classic "Abyssal Recipes" theory sought to explain these abyssal flows, yet later observations exposed two significant conflicts with real-world data. In 2016, Ferrari, McDougall, and colleagues proposed the "Towards a New Abyssal Recipe" framework, introducing bottom boundary layer (BBL) upwelling to address Munk’s inconsistencies. Drawing on recent evidence of a potential cooling trend in the deep ocean, this talk revisits these debates, offering a fresh interpretation of Munk’s discrepancies and proposing a new mechanism for abyssal upwelling in the Indo-Pacific. It contributes to the ongoing quest to unravel how bottom waters complete their global journey.

Presented by: Prof. Dr. HAN Lei
Affiliation: China-ASEAN College of Marine Science, Xiamen University, Malaysia
Address: Sepang, Selangor, Malaysia

 

 

 

 

 

 

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