About sei whale

The sei whale (/ˈseɪ/ or /ˈsaɪ/) (Balaenoptera borealis) is a baleen whale, the third-largest rorqual after the blue whale and the fin whale. It inhabits most oceans and adjoining seas, and prefers deep offshore waters. It avoids polar and tropical waters and semienclosed bodies of water. The sei whale migrates annually from cool and subpolar waters in summer to winter in temperate and subtropical waters, with a lifespan of 70 years.
Following large-scale commercial whaling during the late 19th and 20th centuries, when over 255,000 whales were killed, the sei whale is now internationally protected, although limited hunting occurs under a controversial research program conducted by Japan. As of 2008, its worldwide population was about 80,000, less than a third of its prewhaling population

Additional info

Salinity Marine
Depth Up to 342 meters
Length 1800 cm
Max Weight 30 cm
Red List Crit. Endangered
Threat to Human Not Evaluated

Known names


Balena rostrata, Balaenoptera alba, Balaenoptera arctica, Balaenoptera iwasi, Balaenoptera laticeps, Balaenoptera schlegelii, Balaenoptera schlegellii, Belaenoptera schlegeli, Pterobalaena alba, Pterobalaena schlegeli, Sibbaldius schlegelii

Local names
Australia Sei whale
Red List Status

The cause of the population reduction in Sei Whales (commercial whaling) that occurred in the 20th century is reversible and is understood and has been brought under control.
Following the end of large-scale whaling in the late 1970s, some recovery of the population is inferred based on standard assumptions about the population dynamics.
The species has been listed as Endangered, but plausible projections of the population size indicate that the global population of mature animals may have recovered to around 30% of the 1948 level by 2018.

Related Species

See Also...