FaunaHub
ENEndangeredPartial review

Blue Whale

Balaenoptera musculus

Blue whale (Balaenoptera musculus) surfacing and blowing a tall spout at sea.

Blue whale (Balaenoptera musculus) surfacing in the Arctic.

Image: AWeith, CC BY-SA 4.0, via Wikimedia Commons.

At a glance

IUCN category
EN · Endangered
Animal group
Mammals
Population trend
Increasing
Last verified

Conservation overview

The blue whale is the largest animal known to have ever lived, reaching around 30 metres. It is assessed as Endangered.

It feeds almost entirely on tiny krill, filtering vast amounts of seawater through baleen plates.

Range & habitat

Found in oceans worldwide, migrating between cold feeding waters and warmer breeding areas.

Major threats

Threats below are drawn from the authoritative sources listed on this page. For the current, complete assessment, see the IUCN Red List.

  • Ship strikes
  • Entanglement in fishing gear
  • Past commercial whaling (now recovering)

Why it matters

As the largest animal ever, the blue whale's slow recovery from industrial whaling is one of conservation's most important tests, and the species helps cycle nutrients through the oceans.

The largest animal known to have lived.

Gallery

A mounted blue whale skeleton on display, showing its enormous size.

Blue whale (Balaenoptera musculus) skeleton on museum display.

Image: Xicotencatl, CC BY-SA 3.0, via Wikimedia Commons.

Sources

Sources for Blue Whale

Frequently Asked Questions

How big is a blue whale?
It is the largest animal known to have lived, reaching roughly 30 metres long and weighing well over 100 tonnes — larger than any dinosaur for which we have good evidence.
Why is the blue whale Endangered?
Industrial whaling drastically reduced blue whale numbers in the 20th century. Although now protected and slowly recovering, they remain threatened by ship strikes and entanglement. See the IUCN Red List.

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