SPECIES
Sei whale
Balaenoptera borealis Lesson, 1828
One of the fastest of the great whales, it can travel at more than 48 km an hour.
How big is a sei whale?
12–18 m
How long does a sei whale live?
50–70 years
A fast, solitary filter-feeder
Sei whales usually travel alone or in groups of two to five, and occasionally gather in aggregations of 30 to 50.
They feed on copepods, krill, small schooling fish and squid, in dives of 5 to 20 minutes, and prefer to feed at dawn.
Every ocean, away from the tropics and the ice
Sei whales occur in all the world's oceans, excluding tropical and extreme polar seas, and mostly keep to deeper offshore water.
Scars like small moons
Its body is often marked with oval scars, thought to come from lamprey and cookie-cutter shark bites.
Ships, gear, noise and a moving food supply
Vessel strikes, entanglement in fishing gear, ocean noise and climate change are named threats; climate change is shifting where its prey concentrates.
The worldwide population is estimated at about 80,000 since whaling was banned, while Southern Ocean populations remain severely depleted.
Sources
Records of where it has been seen come live from GBIF; observed interactions from GloBI. Draft — not yet reviewed by a person.