7,000 humpback whales died in the North Pacific over 10 years — and ‘the blob’ is to blame

This is Frosty, a humpback whale known from the west coast of the United States and Mexico, named for the snowman – shaped barnacle scars on the tail. Humpback whale tails display unique pattern and shape allowing researchers to use AI image recognition to track thousands of whales (Image credit: Ted Cheeseman (happywhale))

Around 7,000 humpback whales in the North Pacific Ocean may have starved to death following the disastrous effects of a marine heat wave, a new study reveals.

From 20 years’ worth of data, researchers found that a 20% drop in the North Pacific humpback whale population coincided with a marine heat wave dubbed “the blob” — an event that was responsible for record-breaking mass mortalities of multiple seabird species around the world.

In the 20th century, global populations of humpback whales (Megaptera novaeangliae) were under threat from commercial whaling. An estimated 31,865 humpback whales were killed during the years between 1900 to 1976, dropping the population of humpback whales in the North Pacific to an estimated 1,200 to 1,600 individuals at the end of commercial catches in 1976.

In the new study, published Feb. 28 in the journal Royal Society Open Science, scientists used automated image recognition artificial intelligence (AI) created by Happywhale, a database with thousands of photographs of humpback whale tails sourced from researchers and the public to find out if populations have rebounded.

The AI identified 30,484 individual humpback whales over 132,684 encounters from the photographs of their tail flukes.