How climate change is transforming the Arctic’s underwater soundscape

A male ribbon seal at the Bering Land Bridge National Preserve in Alaska (Photo: Josh London/NOAA)

Oceanographer Kate Stafford uses underwater microphones (called hydrophones) to record the daily sounds of the chilly, chilly waters off the coast of Alaska. For years, she and her team at the University of Washington have been studying the sounds of the Arctic Sea in hopes to better understand the lives of the animals that call this place home.

But Stafford’s recordings reveal more than just the noise of underwater life, she says at TEDxCERN: “What we are hearing on our hydrophones are the very real sounds of climate change.”

What are these sounds? One is wind. Historically, in the Arctic, winter ice has stopped wind noise from entering the water column, giving the underwater Arctic extraordinarily low ambient noise levels. “But with decreases in seasonal sea ice, not only is the Arctic now open to this [wind] noise, but the number of storms and the intensity of storms in the Arctic has been increasing.” And Stafford is capturing this on tape.

Another is new-to-the-Arctic species. As the Arctic loses ice, its seas get easier to navigate, and more attractive to sub-Arctic species, Stafford says. “Everywhere we’ve listened, we’re hearing the sounds of fin whales and humpback whales and killer whales further and further north and later and later in the season.” And these appearances could have disastrous consequences for Arctic species, who are unused to competition from and the biome of sub-Arctic animals.

A bowhead whale photographed by Kate Stafford

And — finally — there’s people. “More open water means increased use of the Arctic by people,” Stafford says, citing cruise ships, oil and gas extraction and commercial shipping. “We now know that ship noise increases levels of stress hormones in whales and can disrupt feeding behavior [and] air guns change the swimming and vocal behavior of whales.”

Sound is key to life underwater for Arctic whales, seals and walruses, Stafford says. Sound lets these animals communicate, evaluate and navigate. “For marine mammals that live underwater where chemical cues and light travel poorly, sound is the sense by which they see,” she says. “And sound travels much better underwater, much better than it does in air … and all of these [new] sound sources are decreasing the acoustic space over which Arctic marine mammals can communicate.”

A ship in the Arctic (Photo: Kate Stafford/TEDxCERN)

“Not only is the physical habitat of the Arctic changing rapidly, but the acoustic habitat is, too,” Stafford says. “It’s as if we plucked these animals up from the quiet countryside and dropped them into a big city in the middle of rush hour — and they can’t escape it.”

Source: https://tedxinnovations.ted.com/2016/11/29/how-climate-change-is-transforming-the-arctics-underwater-soundscape/