Whales are the largest living organisms (生物) living on the surface of the earth. An adult blue whale weighs up to 173 tonnes with 30 meters in length. When a whale dies in the ocean, its body usually falls to the sea floor and a special deep-sea ecosystem will be formed in a long time. Scientists give a name to this: the whale fall.
Recently, some scientists on a Chinese research ship called Tansuo-1 found a whale fall at the depth of 1,600 meters in the South China Sea. Whale falls are seldom found by humans. This is the first time China has found this type of ecosystem. So far, less than 50 modem natural whale falls have been found by humans around the world.
The whale fall is really important to deep-sea animals, as it provides food for them. Usually, the whale fall goes through three stages. The first stage comes just after the whale dies. The body attracts lots of big sea animals such as shark and they come to eat the body. This stage lasts from months to years. At the second stage, smaller animals come for the whale's bones and leftovers. This stage can last one or two years. Bacteria (细菌) play a role at the third stage. They break down what has been left. This stage can last as long as 100 years.
The whale fall found in the South China Sea is 3 meters long. It is still at the first stage. The scientists said it would take them a long time to study the whale fall because they knew it would help them understand the deep-sea ecosystem better.
① Bacteria break down the rest of the whale. ② Smaller animals eat the whale's bones.
③ The whale dies in the ocean. ④ Big sea animals eat the whale's body.
