Commercial whaling has driven species such as the right and gray whales to the brink of extinction. But for other whales, decades of protection are bearing fruit.

The number of humpback whales in the north Pacific has risen to more than 20,000, up from 8,000 in the 1990s and a mere fourteen-hundred in the mid-20th century. The most recent estimate comes after a three-year international study in which scientists catalogued the distinctive tail fin patterns of individual whales.

What’s more, this cheery new tally is probably an underestimate because whales in currently unknown breeding areas escaped the tail count.

So if you ever see a humpback mother and calf leap out of the water off the coast of Alaska, California or Hawaii, thank those dedicated individuals who’ve helped protect these stately giants of the sea.