Researchers have cultivated certain fry in normal seawater and seawater containing twice the concentration of carbon dioxide. The fry grows up and are placed in a maze. Whenever they encounter obstacles, fish hatched in normal seawater will choose the right direction to avoid the obstacles. However, the fish that hatched under high carbon dioxide concentration will randomly choose to turn left or right, so that this fish has a reduced chance of survival when encountering natural enemies. 
The juvenile clownfish were raised in seawater with a high carbon dioxide concentration and played the sounds of natural enemies. As a result, this group of small fish could not hear the sound.
 the researchers believe that the ability of fish to survive in a high carbon dioxide environment will be weakened.