Quiet on the set

(This post was originally published September 30, 2021. Posts have been manually reordered for more logical storytelling. To go to the next post in the sequence, click “Previous Post” at bottom.)

Part of the reason so little is known about the 23 recognized species of beaked whales is because they are so skittish at the surface. Vessels rarely approach within a few hundred meters before the whales slip under the waves, never to be seen again. Depending on the species, individual beaked whales can weigh anywhere from 1 to 12 tons, leaving them with seemingly little to fear in the ocean, but killer whales are nevertheless known to prey on them. Not surprisingly, beaked whales have evolved various behaviors that help them minimize contact with killer whales.

As deep divers — some to almost 3000 meters — beaked whales use echolocation to detect their prey (mainly squid and fish). Although beaked whales can out-dive them, killer whales have the benefit of superior hearing abilities. Consequently, when beaked whales surface to breathe, they quit vocalizing several minutes and several hundred meters below the surface. Then instead of coming straight up, they veer off in random directions to avoid detection by eavesdropping killer whales. At the surface, the beaked whales take a few quick gulps of air and then descend to several hundred meters for 10 minutes or more, before surfacing again. They do a series of these relatively shallow breathing dives before they make their deep foraging dive — the less time they spend at the surface and the less noise they make there, the less likely they are to attract bad company.

A Baird’s beaked whale spotted by the GyreX team near Heceta Bank, Oregon, shows visible tooth rake marks from a killer whale attack.

Beaked whales also have some physical features that make them harder to capture. Their pectoral flippers tuck into “pockets,” making them flush with the body and difficult for a killer whale to bite onto. The dorsal fin, instead of being mid-body like fast-swimming dolphins, is positioned back toward the flukes so that when the tail is pumping up and down, it is also going to be very difficult for a killer whale to grab ahold of.

At 35 feet in length, Baird’s beaked whale (Berardius bairdii) is the largest species of beaked whale, but it is still vulnerable to attacks by packs of killer whales. The photo above shows one of the Baird’s beaked whales that we encountered near Heceta Bank, Oregon; the enlargement reveals tooth rake scars on its dorsal fin left by an attacking killer whale. This whale got away, but Baird’s beaked whales often have killer whale tooth rake marks on them, and it can be assumed that others aren’t so lucky. Little wonder they are wary of their time spent at the surface.

~Bob Pitman


A mystery beaked whale trifecta

(This post was originally published October 6, 2021. Posts have been manually reordered for more logical storytelling. To go to the next post in the sequence, click “Previous Post” at bottom.)

Maps of beaked whale distribution are usually filled with question marks — often more question marks than confirmed sighting locations. These are not small animals (imagine a dolphin that weighs as much as a Clydesdale horse), so what is the problem?

Beaked whales are incredibly difficult to see. They spend mere minutes at the surface and then can disappear for an hour or more. They typically occur in small groups. They become almost invisible in rough seas. And the diagnostic characteristic used to visually identify them to species — the location, size, and shape of teeth in the lower jaw — can only be used for males.

Imagine if we could detect them in any sea conditions and identify them to species just by listening for their distinctive echolocation signals. Our expedition has brought us one step closer to making that hope a reality.

On September 22, Annamaria was monitoring the sounds coming in from our hydrophone towed behind Pacific Storm. Software was translating the inaudible, ultrasonic signals into visual representations, and her computer screen showed a type of beaked whale signal she had never seen before. When, after just three minutes, the mystery whales stopped vocalizing, she knew they would soon be surfacing, so she directed the vessel toward where she thought they were. Despite high winds and heavy seas, making for poor sighting conditions, all aboard were called to join the search with the faint hope of finding the whales before their next dive. After 80 minutes of searching, the two whales found us! They repeatedly approached our research vessel during the next 40 minutes, allowing us to take thousands of photographs and video recordings!

The mystery beaked whale. Photo by Todd Pusser.

Amazingly, despite these close looks, we were unable to identify them to species (once again highlighting how little we know about this group of whales)! But our expedition team does not give up easily. Standing on the bow with crossbow in hand, Bob took aim and fired a two foot-long, lightweight dart at one of the whales. It bounced off the back and landed in the water, floating with the definitive prize: a pencil eraser–sized piece of skin and blubber of our mystery whale caught in the dart tip! This biopsy sample held the key to this species identification in the DNA the tissue contained!

The biopsy dart retrieves a valuable skin sample of the mystery beaked whale. Photo by Todd Pusser.

But the tension would not be relieved until that sample was safely aboard. Two oranges offered up by our cook were thrown to help us keep the floating dart in view while we retrieved our hydrophone (requiring 20 minutes of hand-hauling in heavy seas with the vessel in full stop as the dart and oranges slowly drifted farther and farther away). Pressure mounted as Yogi expertly maneuvered our vessel alongside the bobbing dart. Craig dipped a salmon net into the water and landed our prize on the deck as we all cheered. We had achieved a mystery beaked whale trifecta: acoustic recordings, photographs, and a biopsy sample!

The mystery beaked whale in action. Video by Jay Barlow.

Watch this space for the DNA results!

~Jay Barlow


And the answer is…

(This post was originally published October 14, 2021. Posts have been manually reordered for more logical storytelling. You’ve reached the end. Thank you for reading!)

We are home. Our research equipment is cleaned, packed, crated off the Pacific Storm, and stored locally or shipped to our various colleagues around the country who collaborated with us on this project. GYREX team members have all scattered to their respective winds (some on the other side of the country), and the Storm is already off on other adventures.

But the science continues. Remember that critical biopsy sample we collected from one of our pair of mystery beaked whales? That was the first thing we took from our vessel. It went straight to our Cetacean Conservation and Genomics laboratory at Hatfield Marine Science Center, and Scott Baker and Debbie Steel immediately went to work. Five days later we had our answer. Our mystery whales are Mesoplodon carlhubbsi. This is the Latin name; the common name is Hubbs’ beaked whale. And our biopsied whale is a female.

Our now-identified mystery whale: A female Mesoplodon carlhubbsi. Photo by Todd Pusser.

Let’s put this into perspective.

In 1945, Carl Leavitt Hubbs, a preeminent American ichthyologist, described a beaked whale found alive in the surf near his office in La Jolla, California. Although misidentified originally, the skull and color pattern were different from any whale previously known to science and it ultimately became recognized as a new species — Hubbs’ beaked whale. But for the next 50 years, it would be known only from specimens found dead on beaches.

Fast forward to 1994. The NOAA research vessel Surveyor was conducting a marine mammal survey off the coast of Oregon, when the science team (including Robert Pitman, GYREX visual survey lead) spotted a group of Hubbs’ beaked whales, identified by the unique color pattern of the adult male. It was the first and only time this species had ever been identified alive in the wild. And it would not be identified alive again — until GYREX.

Meanwhile, acousticians, including GYREX acoustics lead, Jay Barlow, were busy listening to the oceans and recording beaked whale signals. One of these, a distinctive and unique signal previously recorded in 2016 and 2018, was named “BW37V” in a paper published in 2019. And it was on the day of our extraordinary encounter with that pair of mystery beaked whales that our GYREX acoustics team recorded it again! BW37V is Hubbs’ Beaked Whale!

Linking an acoustic call with a visual description of a poorly known whale and confirming the species identification through genetics is an extremely powerful tool. Instantly, we now know a lot more about the at-sea distribution of this rare whale; it occurs everywhere BW37V has been recorded! And our visual sightings will provide guidance for future marine mammal scientists at sea encountering mystery beaked whales at the surface — maybe they too are Hubbs’ beaked whales?!

Science often (most often) is part serendipity. In our case, engine transmission problems forced us to give up on our expedition to the infamous garbage patch of the Eastern Pacific Gyre. But after a quick repair in Newport, we used our remaining sea time to explore the offshore waters of Oregon and solved a mystery in our own backyard (although, perhaps only oceanographers and fishermen would consider 197 miles to be our backyard). This — adversity, challenge, risk, camaraderie, and occasionally, extraordinary discovery — is why I became a marine scientist.

~Lisa T. Ballance