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Home > What Happens When a Whale Dies

What happens when a whale dies?

When a whale dies in the ocean, its body sinks to the sea floor. It becomes a huge source of food for the animals that live there.  

A whale’s body can provide food for 100 years or more!

Illustration of animals feeding on a dead whale on the ocean floor.A plus sign that links to a larger version of the illustration.

This illustration shows the first animals to feed on a whale carcass that has fallen to the ocean floor. Illustration by Michael Rothman.

Three groups of animals feed on the whale's body, each in turn:

  • Animals that can swim easily arrive first. Among them are hagfishes and sleeper sharks. These animals eat most of the meat off of the whale’s body. They are known as scavengers, which means they eat animals that are already dead.
  • The next groups of animals are smaller and eat the bits of meat left over by the first group. They are marine worms, called polychaetes, and other invertebrates. There can be billions of individual animals on the whale in this stage.
  • Bacteria make up the third group. They feed on the fat that remains in the whale’s bones after all the meat is gone. This stage can last decades.
  • In total, a whale’s body can produce food for more than 100 years!

Food for the Depths on page 2

Can You Guess My Secret Weapon?

A hagfish. Hagfishes are one of the animals that feed on a whale’s body. Sometimes the hagfishes are attacked by other animals.

How does the hagfish defend itself from these attacks?

It bites the attacking animal
It poisons the attacking animal
It suffocates the attacking animal

More about hagfishes on page 3

See Whales in the Wild

A boy looks at the St. Lawrence River through binoculars. The Saguenay–Saint Lawrence Marine Park protects and presents the marine environment of a section of the St. Lawrence Estuary and the Saguenay Fjord. Five whale species inhabit the waters of the marine park, including the beluga (Delphinapterus leucas), which is a protected species. In all, more than 15 species of marine mammals have been reported—evidence of the marine park's ecological significance.

Protected natural areas (such as national parks and national marine conservation areas) provide the places where natural processes—such as decomposition of a whale on the ocean floor—keep occurring. These processes are important components of any ecosystem; many elements of the ecosystem and many species depend on them.

An image from a video showing hagfishes feeding on a dead whale on an ocean floor.

Watch This Video!

Hagfishes Feeding on a Dead Whale

Video (1 min. 18 sec.)

Food for the Depths

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