It helps them streamline through the water more easily and prevents heat loss. Furthermore, they have a slippery secretion that covers their eyes, protecting the eyes from incoming objects and water friction. Dolphins feed on a diet of fish and they are very efficient in catching these fish. Their powerful tails and sleek bodies allow for them to glide quickly after their prey, and their small but sharp teeth clamp onto whatever they catch. Although they are large, powerful, and fast, they are also preyed on by other animals such as killer whales and large sharks.
Humans are another species of animal that affect dolphins greatly.
Fishing and direct hunting of dolphins have diminished their populations all around the world. Sometimes, dolphins can get caught in the large nets of commercial fishing boats. You may have also seen dolphins at the zoo or the aquarium, but those places take good care of dolphins and keep them healthy. A small fact about zoos and aquariums is that they always use Atlantic bottle-nosed dolphins for their exhibits, even though there are about 36 different species around the world, including some that live in freshwater. In dolphin shows that you see at zoos and aquariums, you always see the dolphins walk on their tales, swim upside down, and other tricks.