Human industry is now noisy enough to drown out whale songs. What would happen in the ocean if we went quiet?
At 5:30am I awoke to the sound of the diesel chug-chugging of a lone lobster boat carving into the glassy Atlantic. An audience of shrieking gulls hushed in the engine’s wake as it rumbled through the narrow strait that separates the United States from Canada. After the boat pushed out into the open ocean, the gulls resumed their gossip, and I began preparing for a day on the water, still groggy from the night before, after joining a group of researchers over beer. I had come to Lubec in Maine with a bizarre question: what was 9/11 like for whales?
I sleepwalked to the pier and helped pack a former Coast Guard patrol boat with boxes of underwater audio-visual equipment, as well as a crossbow built for daring, drive-by whale biopsies. A pod of 40 North Atlantic right whales had been spotted south of Nova Scotia the day before and, with only a few hundred of the animals left in existence, any such gathering meant a potential field research coup. ‘They even got a poop sample!’ one scientist excitedly told me. The boat roared to life and we slipped past postcard-ready lighthouses and crumbling, cedar-shingled herring smokehouses. Lisa Conger, a biologist at the US National Oceanic and Atmospheric Administration (NOAA), manned the wheel of our boat, dodging Canadian islands and fishing weirs. As the Bay of Fundy opened before us, a container ship lumbered by to our stern: a boxy, smoking juggernaut, as unstoppable as the tide.
‘After 9/11, we were the only ones out here,’ Conger said over the wind and waves. While this tucked-away corner of the Atlantic might seem far from the rattle of world affairs, the terrorist attacks on New York City and Washington DC of 11 September 2001 changed the marine world of the Bay of Fundy, too.
Conger leads the field team in Lubec for Susan Parks, a biology professor at Syracuse University. As a graduate student, Parks found that right whales were trying to adapt to a gradual crescendo of man-made noise in the oceans. In one study, she compared calls recorded off Martha’s Vineyard in 1956, and off Argentina in the 1977, with those in the North Atlantic in 2000. Christopher Clark, her advisor, had recorded the Argentine whales and, when Parks first played back their calls, she thought there must be some sort of mistake.
‘It was older equipment – reel-to-reel tapes which I’d never used before – so I went to Chris to ask if I had the speed of the tape wrong because the whales sounded so much lower in frequency than the whales I had been working with.’
In fact, Parks discovered, modern North Atlantic right whales have shifted their calls up an entire octave over the past half century or so, in an attempt to be heard over the unending, and steadily growing, low-frequency drone of commercial shipping. Where right-whale song once carried 20 to 100 miles, today those calls travel only five miles before dissolving into the din. Under the right conditions, fin- and blue‑whale song can carry thousands of miles, as Clark realised while listening in on the oceans using the US Navy’s global submarine detection network. He was stunned to hear a blue whale singer on the Grand Banks of Canada all the way from Puerto Rico, 1,600 miles away. However, it’s an open question whether these performers are actually trying to be heard by their audiences across the ocean.
‘If you have whales spending more time moving out of areas because they’re noisy, or if they have lower reproductive success because they can’t find mates, those seemingly small changes could really add up to a population-level effect where you could cause the birth rate to decline and the mortality rate to increase to the point where, eventually, the populations could go extinct,’ Parks told me.