Marine Mammal Science & Conservation

Blue whale

Blue whale (Balaenoptera musculus)

Group formation: Solitary (mother-calf pair)

Size: males 29 m, females 33 m, calf 7 m

Weight: males 150 t, females 180 t, calf 2.7 t

Spout: 12 m

Age: 60-120 yrs

Sexual maturity: unknown ca 5-15 yrs

Physical maturity: ca. 20 yrs

Gestation: 10-12 mths, with 2-3 yrs in between

Weaning: 6-8 mths

Diet: Krill (euphausiids)

Distribution: Worldwide in all oceans, blue whales in the northern hemisphere are smaller than in the southern hemisphere, north-south migrations

Chile: seen along the coast of Chile (feeding grounds in the Gulf of Corcovado) on their migrations to their breeding grounds at the equator

Population size: global 10.000-25.000, heavily exploited (70-90% reduced)

Conservation Status: Endangered A1abd ver 3.1, Pop. trend: increasing

Threats: Vessel collisions, chemical and plastic pollution, man-made noise impacts (seismic surveys, military sonar), entanglement in fishing gear, over fishing