Japan currently has only four unmanned and manned submersibles
for deep-sea research. Only ten or so such vessels are available
globally, and all are fully booked. Vessel observations so far
have focused on the seafloor. Few observations have been made
on mid- and deep-sea areas that constitute over 90% of the ocean
by volume.
In recent years, it has gradually become clear that mid- and
deep-sea organisms are deeply involved in the material flux between
the deep seafloor and the surface through food chains, or through
vertical migration. Through repeated observations using nets
and cameras lowered from ocean investigation ships, it has become
clear that the mid- and deep sea is rich both in biodiversity
and biomass.
Not only JAMSTEC but also marine research institutions in various
countries are currently carrying out research on mid-and deep-sea
organisms. Using the manned submersibles Shinkai 2000 and Shinkai
6500, and the ROV Dolphin 3K, JAMSTEC has also begun research
on mid- and deep-sea organisms. We performed survey dives from
May to June 1997 in Sagami Bay (depth 1,200 m), Japan trench
(depth 6,500 m), and the Suiyo seamount in Ogasawara (depth 1,400
m), discovering and videotaping many new species. We have also
created a special device for sampling new organisms that are
too delicate for collection with a net. These observations, which
demonstrate that the mid- and deep sea area around Japan is rich
in biodiversity and biomass, could only be made using manned
and unmanned submersibles capable of moving freely through the
deep sea.
A
species of polychaete. This organism swims by using its glass-tube-like
legs as oars in a dance-like motion. Photographed on June 3,
1997, during a dive survey by the Shinkai 6500 in the Japan trench
at a depth of about 6,500 meters.
 A species of polychaete. This organism swims by using its glass-tube-like legs as oars in a dance-like motion. Photographed on June 3, 1997, during a dive survey by the Shinkai 6500 in the Japan trench at a depth of about 6,500 meters. |
A
cranchid squid. The body of this squid is transparent, like a jellyfish.
It controls the amount of a mmonium chloride in its body to adjust
its density, and without moving its fins, can rise in the water
column. It was discovered on June 9, 1997, during the dive survey
of the Shinkai 2000, at depths of 600 to 1,400 meters in the Suiyo
seamount in the Ogasawara Islands.
 A cranchid squid. The body of this squid is transparent, like a jellyfish. It controls the amount of a mmonium chloride in its body to adjust its density, and without moving its fins, can rise in the water column. It was discovered on June 9, 1997, during the dive survey of the Shinkai 2000, at depths of 600 to 1,400 meters in the Suiyo seamount in the Ogasawara Islands. |
Using manned
and unmanned submersibles for observing the mid- and deep sea,
we have discovered many new and previously-unknown organisms.
Such observations are important in resolving the missing link
in the carbon dioxide flux, a significant factor in global warming.
| The discovery of a chemosyntheticecosystem | Mid-and Deep-sea organisms |
| The Effect of a Giant Earthquake |