BY THE NUMBERS

Keeping tabs on our southern right whales

The Whale Unit of the University of Pretoria’s Mammal Research Institute (MRI) will be conducting their annual aerial survey of southern right whales from 30 September to mid-October. Last year celebrated the 50th anniversary of the surveys. It is one of the longest running data sets on any marine mammal worldwide. Here’s what they’ve learnt over the years.

15 000

The estimated global population of southern right whales.

6 000

The estimated regional abundance of southern right whales in South African waters.

2 300

The number of recognisable adult whales added to the MRI database over the past 39 annual surveys.

131

The number of females with calves spotted between Hawston and Witsand in August 2019.

60

The estimated number of reproductive females left when whaling of this species was terminated in 1935.

6,5

The percentage at which southern right whale numbers have been increasing globally per annum, thanks to protection efforts off the coasts of South Africa, Australia and South America.