A new study published in the journal Scientific reports examined how whale watching boats with more powerful engines impact shortfin pilot whales. Previous research suggests that boats can alter the behavior of whales. The impact of boat noise on toothed whales, however, remains uncertain and there are no regulations on noise levels from whale watching boats.

“Commercial whale watching is a multi-billion dollar growing tourism industry around the world,” the study authors wrote. “In 2009, 13 million people participated in whale watching tours in 119 overseas countries and territories, spending more than US $ 2.1 billion.”

“The growth of whale watching globally results in a subsequent increase in the number and / or size of vessels used to observe cetaceans (whales, dolphins, porpoises). Whale watching has been seen as a non-invasive activity and an economical alternative to whaling. ”

“However, whale watching vessels spend a lot of time in the vicinity of cetaceans and, therefore, can have adverse consequences on the health of targeted individuals or populations.”

Patricia Arranz led the research project, which used drones to observe mother-pup pairs of short-finned pilot whales off the coast of Spain. Thirteen of these pairs were observed without the presence of a boat and twenty-three pairs were observed in the presence of boats with either noisy gasoline (gasoline) engines or silent electric motors.

The boats slowly passed the whales at a distance of about 60 meters, in accordance with the laws of the Canary Islands.

Scientists found that whales that were not approached by a boat with a noisier gasoline engine spent more time resting and suckling than those near noisier engines. Mother whales approached by noisy engines spent an average of 29% less time resting and, more worryingly, 81% less time nursing their calves.

With the quieter electric motors, there was no significant change in the behavior of the whales on approach. This suggests that quieter engines may be beneficial for ethical whale watching.

Researchers point out that the less time calves spend suckling and resting, the more energy they consume. This reduces the likelihood that the calves will survive to adulthood.

Research shows that even when current guidelines are followed, whales can be disturbed by their normal behavior. Scientists suggest their findings call for a change in whale watching guidelines and that engine noises should be reduced for the whales’ long-term survival.

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Through Zach fitzner, Terre.com Editor-in-chief