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SCIENCE-JAPAN: The Underwater Wonders Revealed by Kaiko

Suvendrini Kakuchi - Tierramérica*

TOKYO, Jul 24 2003 (IPS) - The Japanese research submarine known as the Kaiko is lost forever, but its legacy lives on. The amazing information it collected from the previously unexplored ocean depths spurred important research in medicine, geology, genetics, biology and even telecommunications.

The small, canary-yellow submersible, which could dive deeper than any other submarine, conducted more than 250 probes resulting in the discovery of 180 bacteria and 350 biological species, some of which could be instrumental in new medical and industrial applications.

So great was the Kaiko’s contribution toward solving the mysteries of the deep, that despite economic obstacles scientists are doing what they can to replace it.

”Kaiko solved many scientific puzzles that contribute to the betterment of mankind, as seen already in studies underway by teams of international scientists. Something must be done (to replace it),” Satoshi Furuta, supervisor of the Japan Marine Science and Technology Centre (JMSTC), the government body in charge of operating the Kaiko.

Lost during a particularly vicious typhoon in the Pacific Ocean in May, the unmanned vehicle was operated by remote control. It measured just three metres long and weighed 10.6 tons.

Kaiko entered the record books in 1995 when it dived almost 11,000 metres to the bottom of Challenger Deep – the world’s deepest stretch of ocean – in the Maruyama Trench, near Guam, in the western Pacific.

Using cylinders inserted by robot arms into the seabed, the Kaiko screened bacteria, leading to the discovery of enzymes, microbes, and genes.

For example, scientist Yuichi Nogi discovered a unique bacterium, moritella yayanosii, during a probe in the Marianna Trench.

Studies of the cream-coloured, sausage-shaped bacteria colony are focusing on developing more potent medicines for hypertension, cancer treatment, and a blood-cleansing agent, says Nogi.

Research has also shown that the bacteria hold proteins such as DHA and EPA, which are widely used in medical treatments.

”This is the first time these proteins were extracted from bacteria rather than fish oil as has been the case previously. This discovery has opened up a whole new world of possibilities in medicine,” Nogi told Tierramérica.

Another exciting discovery was a brilliant violet-coloured dye in the bacteria shewanella violacea, taken during a 6,500-metre dive in the Ryukyu Trench, near the Japanese island of Okinawa.

Research is already underway to develop new cosmetics from the bacteria, which is particularly effective as a skin-whitening agent.

But the shewanella violacea is also being tested for use in semiconductor technology. Scientists like Nogi believe some crystal structures found in the bacteria can be used in developing chemicals to be used in semiconductor production.

Kaiko dives also collected detailed photos of the topography of the seabed, notably details of shifts of tectonic plates and faults, and are expected to contribute to understanding how earthquakes occur, say the scientists involved in the project.

The Kaiko disappeared when the steel cable attaching it to the mother ship, the Kairei, snapped during the May typhoon.

Officials at JMSTC acknowledge Kaiko is lost forever. Furuta explained that the search for the little sub, which was designed to float to the surface and emit a tracking signal, is over.

”Initially there was some hope, but not anymore. The next step will be decided as soon as the report on how the attached cable broke is completed this summer,” he said.

JMSTC estimates the building of a new Kaiko will not cost much more than the original, but the current economic recession makes it difficult to take a decision in that direction.

During its useful life, Kaiko contributed to solving some of the oceans puzzles, such as how life is able to proliferate in the harsh conditions of high pressure, low temperatures and lack of sunlight.

Susumo Ito, director of the Bio-Venture Centre for Extremophiles, commented to Tierramérica that there is a great need for a new Kaiko because the loss of the original has halted studies that were producing important results.

The species found at thousands of metres underwater are known as extremophiles, for their capacity to develop in extreme environments.

In order to be viable at a depth of 6,000 metres, sea life requires a special physiological and biological adaptation, says Nogi.

The discovery of these unique forms of sea life has put an end to the notion that survival in such extreme conditions is impossible, says Shinji Tsuchida, a marine biologist and participant in several probes in the Mariana Trench.

Tsuchida’s exploration in the Indian Ocean in 2000, also found sea life around the so-called ”black smokers”, points at which hot water is released from the ocean floor.

He explains that these species thrive in high concentrations of hydrogen sulphide and methane and a pressure that is a thousand times greater than air pressure at sea level.

”The common theory was nothing could survive in such extreme environments where sunbeams never penetrate. But Kaiko has proved otherwise,” he said.

Kaiko’s probes uncovered several species of marine life, such as the small white bythograeid crab, the long black tubeworm, several species of whitish shrimp and mussels.

The tube worm is particularly interesting as it has no mouth or digestive track and feeds on hydrogen sulphur and sulphide found in the waters off Okinawa that are as hot as 360 degrees at depths of 2,500 metres or more.

An enzyme in their bodies dissolves hydrogen sulphide, a mechanism that holds potential for use in purifying polluted waters, Tsuchida explained.

The Kaiko’s discoveries spurred the creation of a gene library to facilitate the work of genome sequencing and information on microbial evolution.

The library is preparing gene stock taken from more than 1,000 species collected in the ocean’s deepest points, and from species collected by other submarines at shallower depths.

The studies are aimed at looking for identical genes to those in the human genome. If such genes are found, it would potentially contribute to medical treatment through gene therapy, says Nogi.

”The intermediate and deep sea is equivalent to a mountain of treasure,” says extremophile expert Ito. ”We have only begun exploring and there is a lot more to do and discover. Kaiko is thus indispensable for mankind.”

* Originally published July 19 by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme and the United Nations Environment Programme: www.tierramerica.net