Why Do Over 75 Percent of Hawaii’s Humpback Whales Have What Looks Like Acne?

It’s not at all unusual for humpback whales to have large bumps all over their skin. Those fist-sized bumps (tubercles) on their heads are hair follicles. Tubercles are unique to humpbacks and contain whiskers that may detect underwater vibrations to help the whales determine the number of prey swimming nearby.

But marine biologists are concerned about smaller bumps that look like a bad acne breakout and are appearing on more than 75 percent of humpback whales in Hawaii.

Known as nodular dermatitis, these bumps were only on a few humpbacks in the 1970s. That the majority of humpbacks near the Hawaiian islands have them now is very strange.

The humpbacks are also worryingly thin. “You can see their shoulder blades,” Christine Gabriele, a marine biologist with the Hawaii Marine Mammal Consortium (HMMC) who has studied the whales for nearly 30 years, told Science News, “They look angular rather than round.”

Gabriele and some of her colleagues at HMMC are trying to find out what’s causing the acne. To do so, they’re comparing tissue samples from humpbacks with the bumps to whales that don’t have them.

Obtaining the samples is a bit of a challenge.

During their frequent excursions, when a small team of researchers spots a whale pod from their boat, they take photos and enlarge them on an iPad to see whether the humpbacks appear to have the bumps. Then they sail closer to the pod, and marine biologist Suzanne Yin uses a crossbow to shoot a biopsy dart at the whale.

The dart removes a small sample of skin and blubber that’s similar in size to a pencil eraser, Gabriele told Science News. The dart floats in the water until the researchers can pick it up.

Is this process painful for the humpbacks? Gabriele said some whales dive underwater when the dart hits them, while others don’t react at all.

The skin samples then go to the National Institute of Standards and Technology’s Hollings Marine Laboratory in South Carolina, where they’re being analyzed for trace elements. The National Marine Fisheries Service lab is testing the blubber for flame retardants, PCBs and other pollutants.

PCBs, or polychorinated biphenyls, are highly toxic industrial compounds that were banned in the U.S. 40 years ago but still found worldwide.

The results so far show different levels of manganese, a chemical element usually found with iron in minerals, in the whales with the acne, but Gabriele didn’t say what this difference could mean. She told Science News she’s eagerly awaiting the results of the full analyses to get a better understanding of what’s causing those bumps.

Whales already face life-threatening challenges created by humans, like entrapment in fishing lines and collisions with ships and boats. It’s disturbing that manmade pollution could be causing the humpbacks’ acne.

Yet it’s not surprising, since garbage in Pacific Ocean has been growing exponentially. The Great Pacific Garbage Patch between Hawaii and California is now estimated to be twice as large as Texas. All that trash and the contaminants it contains breaks down into microparticles that marine life can mistake for food.

Humpbacks are known to empathize with other species and even risk their lives to save them. It’s the least we humans can do to follow their lead and reduce pollution to help save their lives and the lives of other marine animals in return.

Photo credit: skeeze


Marie W
Marie W3 months ago

Thank you for posting.

Past Member
Past Member 4 months ago

It is sad to note that another species could be at risk.

Danuta W
Danuta W5 months ago

Thank you for sharing

Anna R
Past Member 5 months ago

Thanks for posting

Peggy B
Peggy B6 months ago


Peggy B
Peggy B6 months ago


Renata B
Renata B6 months ago

I agree with Sue H: we all hope to be informed when the full results are available. Very sad state of things, really.

hELEN h6 months ago


Sue H
Sue H6 months ago

An update on the analyses would be nice.

Ruth S
Ruth S6 months ago