August 1, 2013
JAMSTEC
1. Overview
As a part of its scientific survey and investigation of diverse communities of marine organisms inhabiting and evolving in extreme environments of the oceans, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC: Asahiko Taira, President) is conducting a global research expedition for the scientific survey and investigation of ecosystems established in areas with extreme marine environments, as has already been reported on December 13, 2012. The expedition is named "QUELLE 2013," and the research will be conducted in high-temperature hydrothermal vent areas and other unique and extreme environments in the Indian, Atlantic, and Pacific Oceans; the manned research submersible, SHINKAI 6500, and its support ship, the Yokosuka, embarked on this expedition in January 2013.
Investigations in the Caribbean Sea around the British Cayman Islands have been completed and we present an overview of the research.
The SHINKAI 6500 temporarily returned to Japan on August 2 for maintenance work including exchanging its main batteries. After this, it is scheduled to conduct investigations in the Tonga and Kermadec trenches during October and November.
* The research findings from this expedition will be released when the reports are completed.
1. Objectives of Investigations in the Caribbean Sea off the British Cayman Islands
JAMSTEC is conducting comprehensive research on chemosynthetic ecosystems in deep-sea extreme environments; organisms there on the seafloor and in sub-seafloor sediments, some of which use chemical substances as energy sources. As part of this research, investigations off the Cayman Islands on the Mid-Cayman Rise, mainly in the world’s deepest seafloor hydrothermal zones at depths greater than 5000 m, were conducted with the following objectives.
We note that this was the first investigation in this hydrothermal zone by a manned submersible.
2. Overview of Investigations (refer to attached map)
Mid-Cayman Rise (Depth 2200 to 5200 m) in the Caribbean Sea off the British Cayman Islands
The investigations in the Caribbean Sea were conducted jointly with collaborators including the University of Southampton (UK).
* Deep underground in the upper mantle, the main structural rock is peridotite, which is composed of olivine (a structural mineral) and other minerals. Olivine is converted at relatively high temperatures by reaction with water into serpentine (a structural mineral), which is the main component of serpentinite rock. Hydrogen is known to evolve as a-product of this reaction.
A community of Rimicaris hybisae on a chimney in the Beebe hydrothermal vent field seen live by three hundred thousand viewers.
Tubeworm in the Von Damm hydrothermal vent field. It does not appear to be an immigrant species from the Pacific Ocean.
Emerald shrimp with green-colored backs in the Von Damm hydrothermal vent field
Black smoker in the Beebe hydrothermal vent field with high temperatures of about 400 °C
Collection of high-temperature hydrothermal water from a hydrothermal vent named "Hole to Hell" in the Von Damm hydrothermal vent field
Map of study area for this research expedition (Mid-Cayman Rise in the Caribbean Sea off the British Cayman Islands) adapted from Connelly, D. P., et al. (2012) Nature Communication, 3:620 DOI: 10.1038/ncomms1636