Shearwaters, small black sea birds found commonly in the North Bering and Chukchi seas, undulate their flight patterns along each crest and trough of the waves. Sometimes eight or more visit the bow of the R/V Ocean Starr, but often you see them solitary. Flying solo. Their wings come careening so close to touching the water on a downward descent only to flap their way back into a feathered climb. It’s like they surf an imaginary wave above the ocean surface, tip-toeing that fine line between graceful dance and reckless thrill. Up and down they go, millions of times throughout the year, a new wave…a new ocean…a new latitude. Welcome shearwaters, to the Beaufort Sea.
Circling the ship, our resident shearwaters ride their “airboards,” goading and taunting each wave as we cruise to our next research station. Coast Guard cutter Healy is roughly five nautical miles to the starboard beam of the Ocean Starr yet is not visible despite its proximity. The time is 0530 with a low ceiling window—in other words, the visibility is not the greatest. A muted grey horizon and slate grey ocean blurs together like a charcoal rubbing interrupted by the infrequent white cap. The ship eases off the main [engine] and slowly approaches one of the BF stations—the Beaufort Line. The Beaufort transect line is the furthest east our science crew will sail on the first of three cruise legs for the 2019 Arctic Research Program. The RPMs lower, and the boat is quiet for a moment.
Pete Shipton radios to the bridge. “Permission to deploy the transducer,” breaking the momentary silent pause. “Permission granted,” replies Chief Mate Terry Reilly. Attached to a 30-meter cable, the transducer plops into the water off the ship’s starboard. Catherine Berchok stands by a sound receiver and begins entering a series of codes into the machine. She holds one side of the headphones to her ear like a radio DJ with the other ear free to listen to the transducer’s communication to the mooring below.
Catherine Berchok preparing to deploy one of her passive acoustic moorings in the northern Chukchi Sea. Photo credit: Brendan Smith/NPRB
Now imagine this mooring sitting on the ocean bottom in 45 meters (135 ft) of cold arctic water—for a year. The instrument casing is a long cylindrical tube filled with batteries, a hard drive, and a listening device, all sealed air-tight to withstand the harsh northern environment. An 800-lb train wheel serves as its anchor. And the mooring suspends in the water column swaying with the current. For a year, the mooring records the sounds of the Arctic.
Catherine Berchok checking the acoustic monitoring instrument called an Aural. Photo credit: Brendan Smith/NPRB
There’s a ping sound that rings throughout the ship. Lonely, searching, the ping penetrates the ocean to the bottom seeking the mooring about to be recovered. Then, a pong…and another…and now the two devices are speaking with one another in a series of sequential pings and pongs. The hull of the ship sounds as if a submarine has acquired our location like in the Hunt for Red October. Eight, now nine pings—the mooring indicates to the transducer that it is upright. Catherine programs the release code for the mooring to remotely disengage from the anchor. More pings and pongs, and now I am sure that Sean Connery is going to fire a torpedo at our ship. About 200 meters from the bow of the ship, the mooring surfaces.
“Can you hear the ice form?” I ask Catherine in a tonal pitch that drips of incredulity and wonder. Looking up from one of her instruments on the back deck, she smiles. “Actually, you can hear lots of things under water, especially the ice. You can hear it collide with each other…you can hear ice sheets sheering against one another.” While you may not hear the ice particles forming, she assures me that the ice can be heard…or not heard. She goes on to explain that the mooring can also hear wave action and wind, phenomena that have become increasingly frequent in the Arctic waters due to rising ocean surface temperatures.
“It’s [Arctic] also getting noisier,” Catherine continues. There isn’t ice to dampen the wave action and blanket the wind.
Catherine Berchok unbuckling the train wheel anchors for her acoustic mooring. Photo credit: Brendan Smith/NPRB
But that’s not all the noise emanating underneath the ocean’s surface. Vessel traffic and marine mammals are also recorded. Bowhead whales can be heard shrieking, moaning, and making gunshot sounds—all audible to the human ear. From her computer, she plays me a sound like a bomb going off similar to those I hear at the shooting range at Joint Base Elmendorf-Richardson (JBER). It comes from a bearded seal. Walrus make a knocking and gong sound underwater, but above the water, they sound completely different.
Catherine goes on to explain that fin whales have also been heard and observed in the Arctic waters, something that has also received recent attention by the National Oceanic and Atmospheric Administration (NOAA). Sightings of fin whales have been reported north of Barrow, although special acoustic monitoring is required for these huge animals as their vocalizations cannot be heard by the human ear. But it’s the North Pacific right whale that has interested Catherine in the Northern Bering Sea. Due to being one of the most endangered species in the world, understanding the presence, abundance, and relative location of these animals are of critical concern. With Catherine’s passive acoustic moorings, she will be able to listen for these incredible animals, and hopefully as technology improves, gather abundance information so critical for marine mammal management and protection.
The shearwaters return around the ship as Catherine continues to talk to me on the back deck. There is a huge smile when she talks about marine mammals and sound. A visible joy as if she is speaking about her husband and young son. That same kind of smile. I have come to realize that she is one of the hardest working people on the ship, always willing to lend a hand. Selfless and so much to give, it has been a pleasure getting to know her on the ship. She spoke with me about her work all the while setting up an experiment for another science crew member—truly amazing.
As we end the conversation, the shearwaters catch my eye one last time before I head into the ship’s lab. And yes, if you are still reading this, you are probably wondering why I started with these seabirds to begin with. At that moment, it dawned on me that their pattern of flying also resembles that of a wave, like the ocean waves they parallel or how sound is carried underwater. And so, I begin thinking about soundwaves, how far they travel, how different substrates can absorb sound. How singing in the shower sounds different than singing in the living room filled with carpet. I look down at my watch. It’s 0645, and then I wonder how I am thinking about all of this at this time of morning.
…only on a day that includes the ping and pong of science and the Hunt for Mooring BF-2 (our last mooring recovery of Leg One).