Human disturbance hits narwhals where it hurts – the heart


Think about you’re a narwhal. You’re cruising by means of chilly Arctic water if you sense a menace. Most animals, when alarmed, both lash out at their attacker or flee. You, narwhal – the unicorn of the ocean – aren’t most animals.

You will not struggle. Sure, you’ve got an extended tusk rising out of your face. Your tusk, a canine tooth that stretches right into a spiral 5 ft or longer, is not a lot of a weapon. Narwhal tusks are sensory organs crammed with nerves, not uninteresting spears for jabbing at predators or heading off rivals. If an orca swam close by, you’d slink into deeper water or twist beneath ice floes the place the bigger whales can’t comply with.

This menace is uncommon. It is noisy and unfamiliar. As an alternative of the standard flight response, your physique reacts oddly.

You dive, flipping your flippers as quick as they will go. In the meantime, your coronary heart price plummets. It is as in case your coronary heart needs you to freeze in place, just like the best way younger rabbits and deer play possum. (Biologists, borrowing from Greek, name this appearing-lifeless protection “thanatosis.”) But the remainder of you needs to flee. This battle can’t be good in your cardiovascular well being.

The researcher who found this response virtually ignored it. Biologist Terrie Williams of the College of California at Santa Cruz, who research the physiology of huge mammals, spent two summers amassing coronary heart-price and flipper-exercise knowledge from wild narwhals in Greenland.

The whales have been stranded or caught in nets. Earlier than chopping the whales unfastened, scientists outfitted the animals with a monitoring gadget. Instantly the narwhal our bodies confirmed this conflicting response.

“My first inclination was to throw out the primary couple of hours,” Williams stated. “The animals have been doing one thing bizarre. It was clear it wasn’t a traditional dive response.” Solely later did she understand the weirdness was within the whales’ response to people.

Williams had developed the gadget, a mixture EKG monitor, accelerometer and depth meter, to review marine mammals; she first examined it on retired dolphins that had been educated to work with the Navy. The machine was tailored for narwhals, made extra rugged for colder and deeper water. Collaborating with Greenland’s Institute for Pure Assets, Williams and her colleagues caught the monitor to wild whales with suction cups.

A number of days later, the monitor fell off and floated to the floor, the place Williams and her teammates situated it by way of VHF and satellite tv for pc alerts. They repeated the method for…



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