Many ocean-dwelling animals can use sound waves to communicate with other animals and locate food and obstacles over longer distances than can land-dwelling animals. how is this possible

Well, this is called echolocation. It is possible because the animals make noise, and it bounces off objects and plants. Their brain takes the sound waves that bounce off objects and register it into their brain at another way of seeing. They can see up to 200 miles away with this, and other animals can hear these noises from far away. I hope this answer cam to your desired help.