Story at a glance
- Researchers from the University of Copenhagen and the Greenland Institute of Natural Resources found that narwhals face an additional threat.
- The whale species is “highly affected” by noises from ships and seismic airgun pulses.
- Researchers hope that lawmakers in Canada, Norway and Greenland will do something to regulate noise pollution from ships to help protect the species.
Increasing temperatures, melting ice caps and acidifying oceans are all threatening one of the Arctic’s most iconic animals, the narwhal, and now the species faces a new threat: noise, according to a new study.
The study from the University of Copenhagen and the Greenland Institute of Natural Resources found the threatened whale species are “highly affected” by noise from ships and seismic airgun pulses.
Narwhals rely heavily on sound for survival in part because they spend a huge portion of their lives in darkness. The Arctic is dark for six months out of the year and the whales hunt for food at depths of up to 1,800 meters where light can’t reach. Similar to bats, the species uses echolocation to orient themselves in dark waters as they travel or hunt.
Ship sonars have proven to be a serious problem for humpback whales, dolphins and orcas, a species that also uses echolocation, according to The Guardian, and researchers have been curious to learn more about how narwhals respond to sound as shipping activity is predicted to increase due to melting sea ice caused by climate change.
For two weeks, researchers positioned a ship in the Scoresby Sound fjord system in East Greenland to expose a herd of narwhals to noise from the ship’s engine and a seismic airgun used for oil exploration, according to the study, and documented their response.
“The narwhals’ reactions indicate that they are frightened and stressed. They stop emitting the click sounds that they need to feed, they stop diving deep and they swim close to shore, a behaviour that they usually only display when feeling threatened by killer whales. This behavior means that they have no chance of finding food for as long as the noise persists,” said marine biologist Outi Tervo from the Greenland Institute of Natural Resources, one of the researchers behind the study.
The narwhals would respond to noise up to 40 kilometers away, and researchers observed the whales would “make an uncommon number of strokes” with their tails when trying to distance themselves from the ship. Researchers worry that the increased strokes could be dangerous for the whales since it depletes their energy reserves
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