Silence can save the narwhales

Research shows that sounds expose narwhales to a high level of stress. Turning down the volume on manmade activities can make a big difference, says Outi Maria Tervo.

By Phillippa Mangalika Maigaard Filtenborg

In Eastern Greenland, scientists have been monitoring narwhales’ sensitivity to sound. Outi Maria Tervo from Pinngortitaleriffik, Greenland Institute of Natural Resources, is one of the scientists behind the project.

“We captured them and put different kinds of tags on them. That gave us a chance to monitor their behavior. Then, we exposed them to different kinds of sound to find out how the whales responded,” says Outi Maria Tervo.

High level of stress

The team of scientists learned that sound exposure had tremendous effect on the whales. For one thing, they stopped foraging. They would move away from the sound source quickly and generally try to avoid it completely.

“Monitoring narwhales also showed that their hearts were beating irregularly. We believe they get stressed and frightened by the sound and that’s why their heartbeats become very irregular. That can be very dangerous for the individual narwhale,” says Outi Maria Tervo.

Outi Maria Tervo explains that it is sounds from manmade activities as traffic, cruise ships and mining that creates disturbance. Those activities are increasing in the Arctic – and in many localities in Greenland.

Scientists acknowledge the need for money and self-sufficiency causing these activities.

“It’s possible to find a balance. It’s absolutely necessary that humans can also be on this planet, and we still need the money that flows into Greenland and other countries in the Arctic from tourism, fishing and mining.”

As an alternative, scientists suggest designated areas reserved for narwhales or putting a limit on traffic in selected seasons. She also recommends a discussion on whether ships that sail in the area should slow down to reduce noise.

“If it’s possible to do some or all these things, it can be crucial in helping to preserve the narwhale population. At the same time, it will allow narwhales and humans to coexist,” says Outi Maria Tervo.