North Atlantic right whales shrink

Study says generation averages 3 feet shorter

One of the giants of the deep is shrinking before our eyes, a new study says.

The younger generation of critically endangered North Atlantic right whales are on average about three feet shorter than whales were 20 years ago, drone and aircraft data show in a study in Thursday’s journal Current Biology.

Entanglements with fishing gear, collisions with ships and climate change moving their food supply north are combining to stress and shrink these whales, the study says.

Diminishing size is a threat to the species’ overall survival because the whales aren’t having as many offspring. They aren’t big enough to nurse their young or even get pregnant, study authors said.

These marine mammals used to grow to 46 feet on average, but now the younger generation is on track to average not quite 43 feet, according to the study.

“This isn’t about ‘short’ right whales, it’s about a physical manifestation of a physiological problem. It’s the chest pain before the heart attack,” said Regina Asmutis-silvia, executive director of Whale and Dolphin Conservation North America,

who wasn’t part of the study. “Ignoring it only leads to an inevitable tragedy, while recognizing and treating it can literally save a life, or in this case, an entire species.”

There are only about 356 North Atlantic right whales left, down from 500 in 2010, said study co-author Amy Knowlton, a senior scientist at the New England Aquarium. Other estimates put the population around 400, though researchers agree the population is shrinking.

In the past, scientists and activists

have concentrated solely on whale deaths, but now they realize there’s a problem afflicting surviving whales that can still cause populations to further dwindle, said study co-author Michael Moore, marine mammals director at Woods Hole Oceanographic Institute. The authors were able to take pictures of 129 of the right whales and use a computer program to compare them to right whales of similar age 20 years ago.

The study authors said the No. 1 issue is entanglement in fishing gear.

Florida Fish and Wildlife Conservation Commission A female North Atlantic right whale, right, swims with another whale on Feb. 20, 2010. She died in February 2011. Only about 356 North Atlantic right whales remain.