“Intense industrial whaling during the 20th Century virtually wiped humpbacks out, leaving less than 5% of pre-whaling numbers in the ocean. But 40 years ago, a global whaling moratorium came into force and populations began to recover.

Today, while some humpback populations remain endangered and for others the rate of recovery is uncertain, globally humpbacks are on the rise. In the southern hemisphere, humpbacks have shown a strong recovery, with an increase in numbers of up to 12% per year. Now, South Africa’s recent humpback super-group bonanza could indicate a turning point in the resurgence of the humpback whale.

Sightings of super-groups – defined as groups of 20 or more humpback whales that are within five body-lengths of their nearest neighbour – are also skyrocketing.

Experts aren’t yet sure why we’re seeing this sudden surge in these gatherings. It could be a change in prey availability, or an increase in the numbers of whales elsewhere prompting exploration of new feeding strategies or areas. Or perhaps this is something they’ve always done, but only now are we witnessing it as populations recover.”

From BBC.