Humans are changing the way the ocean sounds, and it is having a profound impact on marine life. A major new literature review published in Science on Thursday found that noise from vessels, sonar, seismic surveys and construction can damage marine animals’ hearing, change their behaviours and, in some cases, threaten their ability to survive.
With rumbling ships, hammering oil drills and booming seismic survey blasts, humans have drastically altered the underwater soundscape — in some cases deafening or disorienting whales, dolphins and other marine mammals that rely on sound to navigate, researchers report in a metastudy to be published Friday by the journal Science that examines more than 500 research papers. Even the cracking of glaciers calving into polar oceans and the rattle of rain falling on the water’s surface can be heard deep under the sea, said lead author Carlos Duarte, a marine scientist at King Abdullah University of Science and Technology in Saudi Arabia.
Marine scientist Dr Heather Koldewey, from the Zoological Society of London, said that the underwater realm was a “a cacophony of sound as animals meet, greet, breed, and use noise in a variety of ways”. “It’s is an important yet overlooked aspect of what constitutes a healthy ocean,” she added. But the scientists pointed out that the global lockdown revealed how quickly and easily the problem of noise pollution could be solved.
“Last year, when 60% of all humans were in lockdown, the level of human noise [in the ocean] reduced by about 20%,” said Prof Duarte. “That relatively modest reduction was enough for a wave of observations.”Large marine mammals – the easiest to observe – were seen near coastlines and in waterways that they’d not been seen in for generations.”
“In theory, you can reduce or turn off sound immediately — it’s not like plastics or climate change, which are much harder to undo,” Francis Juanes, study coauthor and University of Victoria ecologist, told The Associated Press. Despite this, noise is not mentioned in the UN’s Law of the Sea B.B.N.J. agreement or its 14th sustainable development goal, which focuses on ocean life, The New York Times reported. Researchers hope that their work will inspire policy makers to take ocean noise seriously and deploy already available solutions.
“Slow down, move the shipping lane, avoid sensitive areas, change propellers,” Steve Simpson, study co-author and University of Exeter marine biologist, told The New York Times.