A population of blue whales has reached pre-whaling levels and is no longer endangered.

Cole Monnahan at the University of Washington in Seattle and his colleagues modelled a population of blue whales (Balaenoptera musculus) in the eastern North Pacific along with the number of ships and their collisions with the mammals between 1905 and 2050. They found that whale numbers in this region were at their lowest in 1931 and have since increased to about 2,200 — nearly the maximum population size that the ecosystem can sustain.

The team also estimates that ship strikes are unlikely to threaten the population in the near future, but says that collision numbers are currently above legal US levels.

Mar. Mammal Sci. http://doi.org/vh8 (2014)