Noisier Oceans Could Cause a Critical Food Source to Disappear
Seismic air guns sound like bombs exploding underwater.
Massive engines rumbling, industrial propellers churning, and seismic air guns blasting — these are the sounds that dominate life underwater in many parts of the world’s oceans.
And these excruciating sounds could soon get worse, as bans on drilling for oil in swaths of the Atlantic Ocean and Pacific Ocean get lifted and commercial traffic on the world’s seas increases, according to the New York Times.
Seismic air guns are especially harmful — each blast sounds like a bomb exploding. When companies explore for oil fields, they shoot seismic blasts into the water that bounce off the seafloor and return to a sensor that can tell if oil is present. These guns — in arrays of up to 48 — fire every 10 seconds during exploratory missions and make it nearly impossible for nearby marine animals to communicate or decipher sound.
“It’s ripping the communications system apart,” Christopher Clark, a senior researcher in the bioacoustics program at the Cornell Lab of Ornithology, told the Times. “And every aspect of their lives is dependent on sound, including finding food.”
The blasts, along with other sonic sounds, cause immense stress, disrupt mating and eating habits, damage organs associated with spatial orientation, and can even directly kill marine creatures, according to the Times.
Sound travels faster and farther through water than air, and marine animals have evolved highly sophisticated hearing and speaking capacities over time as a result.
Marine animals use sound to find prey, avoid predators, perceive incoming storms and shifts in water patterns, communicate with peers, and much more.
Read More: 87% of the World’s Oceans Are Dying: Report
In recent decades, however, the web of life that underwater sound creates has been increasingly disrupted by human activity. And now these effects are coming back to haunt humans. As powerful sounds proliferate, fishing vessels are having trouble locating fish, which could endanger a crucial source of food for billions of people.
One study found that a blast softer than a seismic air gun killed the vast majority of zooplankton in the surrounding area. Zooplankton support marine food chains and their disappearance would cause species up and down ecosystems to vanish.
Other studies have found that fish and other creatures actively avoid zones of elevated sound or migrate to new areas. In the process, animals have died from decompression sickness after trying to dive deeper and have frozen to death after fleeing to colder, less traveled regions.
In Norway, fishing vessels caught 40% to 80% fewer fish when seismic guns are blasting in nearby areas.
More than 3 billion people depend on fish as a primary source of protein, and around 1 in 10 people around the world could face malnutrition as fish catches decline.
Further, more than 60 million people work in fisheries and aquaculture, and their livelihoods could become imperilled if fish populations drop.
Sound pollution isn’t the only threat facing marine life.
Oceans are absorbing the majority of the excess heat caused by climate change, rising to temperatures that are inhospitable to coral reefs, fish, crustaceans, and more.
They're also absorbing the bulk of carbon produced by human activity, which causes water pH levels to acidify to levels that harm marine life.
These are just a few of problems facing marine life, but they collectively paint a grim picture of the oceans, once vast realms of vibrant life, becoming wastelands.