ABOARD KEXUE - Chinese scientists aboard research vessel Kexue (Science) photographed several "seabed gardens" with colorful corals and sponges on Tuesday in a seamount of Mariana Trench, located in the western Pacific Ocean.

The coral gardens were discovered in the east ridge of the seamount in the south of the Mariana Trench, the deepest place of the earth, by a remote operated vehicle (ROV).

The western Pacific Ocean within 20 degrees of latitude is an oligotrophic sea area because it is far away from land and lacks supplement of nutrients. The upside and bottom seawater in these areas rarely exchange as the temperature is steady the whole year, therefore, the nutrients at the seafloor can not be brought up.

However, the ocean currents towards the east ridge of the investigated seamount are complicated and fast, so they can bring lots of organic matters to feed corals, Xu said.

The east ridge of the seamount has a steady geological environment and its bottom is made up of large rocks, which provides a stable base for the corals and sponges attached to them, he added.