Why do sharks not hibernate?

Sharks are active year-round and do not hibernate. This is because they are ectothermic, which means that they rely on external sources of heat to regulate their body temperature. When the water temperature drops, sharks will move to warmer waters to maintain their body temperature. Some species of sharks, such as the great white shark, will travel long distances to find warmer waters. Other species of sharks, such as the nurse shark, will stay in the same area but will find sheltered spots to hide in during the colder months.