Here's a breakdown:
Dolphins:
* Worldwide: Found in all oceans, both warm and cold.
* Coastal and open ocean: They prefer coastal areas, but also inhabit the open ocean.
* Freshwater: Some species, like the Amazon River dolphin, live in freshwater rivers.
Sharks:
* Worldwide: Found in all oceans, but some species prefer specific climates.
* Various depths: From shallow coastal waters to the deep ocean.
* Freshwater: A few shark species, like the bull shark, can tolerate freshwater for short periods.
Both dolphins and sharks are rarely found in freshwater environments. The majority of both species reside in saltwater oceans.