South China Sea Is Home To World’s Deepest ‘Blue Hole’, New Study Finds [VIDEO]

A new study conducted by a team of Chinese researchers has found that "blue hole" in the South China Sea is currently the world's deepest underwater sinkhole.

The "blue hole" also referred to as the Dragon Hole or Longdong measures almost 300 metres deep. The Dragon Hole entrance measures 130 meters wide, reported CBSNews. Dean's Blue Hole located on Long Island in the Bahamas previously hold the record of being the world's deepest underwater sinkhole, at a depth of 202 metres.

Get to know newly-confirmed world deepest blue hole! Locals call it "eye" of #SouthChinaSea https://t.co/tmk5mQyItw pic.twitter.com/LL3WE2lehB

— China Xinhua News (@XHNews) July 23, 2016

It was in August last year when the research team from the Sansha Ship Course Research Institute for Coral Protection began exploring the "Dragon Hole" and finished the project only last month, China Topix reported. They used an underwater robot named VideoRay Pro 4, which was equipped with a depth sensor, sonar scanners, underwater cameras and deep-sea current metres to calculate the size of the sinkhole. The research project was supported by the Sansha City Government in the Chinese island province of Hainan.

The researchers detected more than 20 fish species and other marine organisms in the upper levels of the blue hole. However, they found that there was almost no oxygen at a depth of 100 meters in the sinkhole, and thus no life, reported Daily Mail.

According to the researchers, studying more about blue holes is very crucial for marine research as well as developing projects aimed at providing benefits to the marine environment.

A blue hole is a large sinkhole in the ocean which is formed over thousands of years when large deposits of limestone and other carbonate rocks dissolve. It begins as a cave hidden beneath the ocean floor. The name "blue hole" reflects the color contrast between the dark blue inside the hole and the light blue waters surrounding it.

In wake of the recent discovery, the Sansha city government has officially named the sinkhole as the Sansha Yongle Blue Hole on July 24, 2016. In fact, the government has also drafted plans to continue to protect and study the blue hole.

Xu Zhifei, vice mayor of Sansha City, told Xinhua News that the government will do its best to protect the natural legacy left by the Earth.