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Science & Nature • Marine Mammals

Dolphin

Dolphins are a widely distributed group of toothed marine mammals in the order Cetacea, found in oceans and, for some species, rivers and estuaries.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Dolphins are a widely distributed group of toothed marine mammals in the order Cetacea, found in oceans and, for some species, rivers and estuaries. They are carnivores that mainly eat fish and squid, and many species are known for complex social behaviour and echolocation.

Characteristics

Dolphins are toothed whales and therefore marine mammals, not fish. They breathe air, give birth to live young, and nurse their offspring with milk. They use echolocation and are widely recognized for complex social behaviour.

Diet and feeding

Dolphins are active predators that primarily feed on fish and squid, with crustaceans and other prey also common depending on species and habitat. They are carnivorous mammals that eat mostly fish, squid, and crustaceans.

Habitat and distribution

Dolphins occur worldwide in oceans, coastal waters, estuaries, and for some species, rivers and other freshwater or brackish environments. Dolphin species live in a wide range of aquatic habitats, including marine, brackish, and freshwater environments.

Conservation

Dolphin species face different threats and are not all equally at risk; conservation status ranges from Least Concern to Critically Endangered depending on the species. Some dolphins are not threatened, while others are endangered or critically endangered.

Key facts

  • Dolphins are carnivorous mammals that eat mostly fish, squid, and crustaceans.
  • Dolphin species live in a wide range of aquatic habitats, including marine, brackish, and freshwater environments.
  • Conservation status differs by species; some dolphins are not threatened, while others are endangered or critically endangered.
  • Dolphins use echolocation and are widely recognized for complex social behaviour.
  • Most dolphins live in warm or temperate waters, though some species occur in colder regions.
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Canadian context

Canada has several dolphin species in its marine waters, including coastal and offshore Atlantic and Pacific habitats, and Canadian conservation efforts address marine mammal protection and bycatch risks.

Frequently asked questions

What do dolphins eat?
Dolphins are carnivores that mainly eat fish and squid, and many species also eat crustaceans such as shrimp and crabs.
How long do dolphins live?
Lifespan varies by species. Many dolphins live several decades, but exact life expectancy depends on the species and conditions; some sources do not give a single universal number.
How fast can dolphins swim?
Swimming speed varies by species. Dolphins are fast swimmers, but a single universal speed does not apply to all species; published sources in the provided results do not give one consistent figure.
Are dolphins endangered?
Some dolphin species are endangered or critically endangered, but others are not threatened. Conservation status varies widely by species.
Where do dolphins live?
Dolphins live in oceans, coastal waters, estuaries, and, for some species, rivers and other freshwater or brackish habitats.
How intelligent are dolphins?
Dolphins are generally regarded as highly intelligent animals with complex social behaviour and advanced communication abilities, including echolocation.

References

  1. Dolphin World — https://dolphinworld.org/dolphin-diet/
    Supports: Dolphins are carnivores; diet includes fish, squid, jellyfish, shrimp, octopus; habitat range includes rivers, estuaries, coastal waters, and open ocean.
  2. Wild Dolphin Project — https://www.wilddolphinproject.org/diets-of-dolphins-whales-and-more/
    Supports: Dolphins primarily feed on fish, squid, and crustaceans; dolphins are intelligent and social.
  3. A-Z Animals — https://a-z-animals.com/blog/what-do-dolphins-eat/
    Supports: Dolphins are carnivores; diet includes fish, squid, crustaceans, jellyfish; some larger species may prey on larger marine animals.
  4. SeaWorld — https://www.seaworld.org/animals/all-about/bottlenose-dolphin/diet
    Supports: Bottlenose dolphin diet includes fish, squids, crustaceans; adults eat about 4% to 6% of body weight daily.
  5. IFAW — https://www.ifaw.org/animals/dolphins
    Supports: Dolphins are carnivorous apex predators; habitat range includes saltwater and freshwater; conservation status varies from Least Concern to Critically Endangered; dolphins are mammals.
  6. Wikipedia — https://en.wikipedia.org/wiki/Dolphin
    Supports: Dolphins are widespread in marine, brackish, and freshwater bodies; diet largely fish and squid; some large-bodied dolphins prey on larger marine animals.