Chase the ghost of the ocean

More at 60 miles off the coast of Baja, California, the crew of the Pacific storm transported an underwater microphone behind their boat while scanning the horizon with twins for signs of life.

For years, researchers have sought the source of an acute click frequently detected in these waters. They had given him a name: BW43. BW for beak whale and 43 for the frequency of tone, which peaks at 43 kilohertz. Modified for perception by human hearing, noise sounds like a series of fast clicks, such as operating a nail along the teeth of a plastic comb. In 2024, a team of scientists from the United States and Mexico embarked on a special research expedition to resolve the mysterious source of sound.

The tenth morning of their trip, an observer on the boat has seen a dark and spindle -shaped shape emerge from depths at a distance. Two whales struck and jostled on the surface of the water around the boat. Scientists rushed to prepare their cameras and acoustic recorders. Suddenly, a whale emerged less than 65 feet from the stern, and Robert Pitman, a whale researcher at the University of Oregon, targeted a flagship of whale biopsy, cutting a precious sample of skin and grease, which has plugged into the water. A hungry albatrosses stabbed the dart containing the piece of fabric, but scientists managed to grasp the device before the bird flies with it.

All these beak whales have their own unique acoustic signals. They are like birds.

“We were all ecstatic, that was what we had worked for the whole trip and we finally got it,” explains Elizabeth Henderson, bioacoustician at the Naval Information Warfare Center in California.

The research team also picked up a sample of water in the wake of whales in the hope of glean DNA spots, and their hydrophones continued to record many clicks while the whales disappeared in the depths of the ocean. A few weeks later, the analysis of the DNA of the biopsy revealed that the whales were with gingko toothbooks. This June morning marked the first live -confirmed live observation of the species at sea. And because the researchers managed to obtain a DNA sample and an acoustic recording in one go, they were finally able to confirm that it was indeed the animal that made the BW43 call. Their results were recently shared in a new study published in Science of marine mammals.

According to the Society for Marine Mammology, 94 species of cetaceans roam the rivers and the oceans of the world, and about a quarter of them are beaks. Marine mammals can reach the length of a bus and are fleshy and tubular, with heads shrinking towards a pointed beak. Of the 24 species of beak whales, 16 and counting belong to a genus called MesoplodonThe most special of all kinds of whale. To date, scientists know almost nothing about this diverse whale group. “These are the least well -known big animals on this planet,” explains Pitman. “We don’t even know how many species there are.”

Historically, the beak whales were almost impossible to study. They live far offshore, plunged deeply and generally do not surface for a few minutes before disappearing again. They are defenseless against the killers and, as such, are tight in nature and plunge into the depths of the ocean to hide. What scientists know about different species of beak whales come largely from drying – specimens have raised the specimens that taxomists study to say definitively one species of another.

Identifying a mesoplodon in nature is rare, it is almost impossible to determine a free swimming animal. The most distinctive characteristic of all known species of the Mesoplodon is a defense -shaped snaggletooth which protrudes from each side of the jaw on males, mainly used for display and combat. In some cases, these teeth make it difficult for creatures to open their mouths. Often, the best way for observers to recognize a mesoplodon is to catch an adult male bare teeth.

“I never thought we would know anything on the beak whales,” says Pitman, who has been studying marine mammals for almost 50 years. Studies from the 1980s, he said, have adopted a fairly pessimistic vision of the possibility that scientists are able to learn anything about these creatures.

But with the help of modern acoustic and genetic technologies, it changes quickly. “It turns out that all these beak whales have their own unique acoustic signals. They are like birds, ”explains Pitman. Once the researchers can match an echolocation impulse to a specific species, they can passively monitor oceanic sounds to listen to the different species of beak whales rather than rely on the serendipity and a lively eye. Hydrophones at high frequency can be towed behind ships, he says, or anchored at the seabed. Microphones can also be fixed to buoys and deposited in areas of interest to collect later.

They are the least known large animals on this planet.

All of these methods are much cheaper than Manning a team specializing in sea, adds Sasha Hooker, whale researcher at the University of St. Andrews in the United Kingdom who was not involved in the study. Certain acoustic signals have not yet been linked to specific species and vice versa. “Assort them then makes everything much more powerful.”

The Gingko teeth beak whale is only the last of a series of live observations genetically confirmed genetically associated with acoustic signals: in 2021, Pitman and his colleagues equaled hubbs beaks to a call known as BW37V off the coast of Oregon, and the same year, the researchers spotted the northern rales of the northern ship. In 2023, the researchers confirmed the first live observation of the deraniyagala beak in the Southern China Sea.

However, the mysteries abound. Perrin’s beak whales are probably the most elusive of the group. They were only seen by drying, six of which were recorded. Pitman pulls to see these whales live in nature and associate them with an acoustic signal. Similarly, the Hector beak whales and the spade must still be identified live in the wild. The most mysterious of all – if it even exists – is the beak whale of the cross. Scientists first recorded a distinctive impulse near Hawaii 20 years ago, but no one could correspond to the sound with a known species, so they named it from the Mount Sousmarin where they first recorded the call.

“At this stage, I think it is very important to learn to distinguish these species, because we can then go into the following mode, which discovers where they are and how they go,” explains Pitman. Thanks to passive surveillance, scientists could determine where species and abundance live.

These efforts have a certain urgency. Pitman and Hooker fear that already rare beak whales can disappear before learning anything about them. More and more images of beak whales show scars from fishing lines, and the military sonar can frighten the whales, sometimes causing net mass. The anthropogenic aggressions on the ocean – overfishing, climate change, the shipping of traffic – accumulate. Who knows what effect they might have on these elusive whales.

“It is incredible that there is something in the ocean that we know nothing,” explains Pitman. “Technology arrives at the rescue. I just hope it is not too late. ”

To find out more about whales in the pages of NautilusDiscover these stories:

The whales failed by the sun: is the flaw of whales partially in the stars?
Who speaks for whales? The rights of cetaceans are not enough. They also deserve a representation.
The large rolling carpet of whales: the loss of whales has weakened the longest food chain in the planet

Image of lead: Craig Hayslip

• Marina Wang

  Published on September 23, 2025

  Marina Wang is a multimedia journalist in Calgary, Alberta. His work appeared in Hakai, atlas obscuraCBC, Scientific magazine, Canadian geographicand many other publications.