Japanese scientists recently found that the March 11 magitude-9 earthquake created fissures on the ocean floor across the region and destroyed the deep sea eco-system.
Researchers at Japan's Agency for Marine-Earth Science and Technology said they found a number of fissures, some of them as wide as one metre (3.3 feet) during their surveys at the 5,000-metre (3.1-mile) deep-sea banks near the quake-hit Sendai City, Miyagi Prefecture, earlier this month.
The team also found that the sea organism they used to observe across the region during their past researches were no longer there after the mega-earthquake and tsunami caused underwater mud-slides and changed the composition of the soil.
“The March 11 earthquake destroyed the ocean floor with fissures and mud slides. We discovered that the deep sea organisms which used to be there were totally eliminated or replaced by new species,” said ocean biologist Katsunori Fujikura.
What the team also found inside the fissure were white, gelatine-like deposits; clods of bacteria that react with methane gas to seep through the cracks of the ground.
Fujikura said the bacteria could irreversibly damage the deep sea eco-system as they produce toxic substances, making the sea bed inhabitable for other organisms.
“The bacteria produce hydrogen sulphite, which is toxic for other organisms, so, they can no longer live there,” said Fujikura.
He also said long-term research is needed to figure out whether the ocean floor's ecological system can be revived.
“We don't know yet whether the deep sea eco-system can recover, although I'm pretty sure that it will keep changing the way it looks. We may need to monitor this area for long time to say how it's actually changed,” he said.
Japan's Meteorological Agency marked the Richter scale 9.0 earthquake that jolted Northern Japan on March 11 as the largest to hit the country since records began in Japan 140 years ago.
It was also the fifth most powerful quake to hit the world in the past century.