A major study reveals that human-caused noise pollution affects 80% of wildlife species, forcing predators to work harder for less food and driving animals from their habitats.
By Adam Makins·
Listen closely to an underwater seagrass meadow and you might hear something extraordinary: the actual sound of photosynthesis. Tiny oxygen bubbles released by seagrass during daylight hours create a tinkling bell-like sound as they burst at the ocean’s surface. It’s a natural symphony most of us will never experience, drowned out by the relentless roar of human activity.
This acoustic phenomenon represents everything we’re losing. Ocean ambient noise levels are now about 10 times higher than they were in 1950. For marine creatures, it’s like living in an endless party, 24/7, with no escape.
Just how bad is noise pollution for wildlife? A meta-analysis published in Science examined 214 experimental studies across 177 species on six continents. The findings are sobering: noise pollution altered at least one physiological, developmental, or behavioral trait in 80 percent of species studied.
“Every ecosystem, or every major habitat, is affected by noise,” says Hansjoerg Kunc at Queen’s University Belfast. This isn’t a problem confined to cities or busy shipping lanes. It’s everywhere.
The ecological damage is measurable and severe. Predators now work 2.5 times harder to catch 25 percent less prey. Bats expend more energy and fail more often at hunting. Ship engine noise disrupts the communication of whales and dolphins, disorienting these highly intelligent marine mammals. Mortality rates among studied animals jumped by 138 percent on average in noise-polluted areas.
Sometimes the death is instantaneous. Underwater explosions from oil and gas exploration can cause fish bladders to rupture. Other times it’s slower and crueler: gradual starvation from hunting failure.
Animals are voting with their feet, or fins. Dolphins actively avoid noisy coastlines. Bats have been observed avoiding roads long after a motorcycle rally ends, having learned that certain places mean danger. When wildlife abandons habitats, populations shrink. The available territory contracts.
While some predators might temporarily benefit when human noise flushes prey from hiding spots, Kunc argues this misses the point entirely. “If you think about an ecosystem, all species in this ecosystem have adapted to the way it should be,” he says. Changing that equation damages the whole system, not just individual losers.
Conservation efforts must adapt accordingly. In the US, national parks like Yellowstone have designated quiet zones that reduce visitor noise by 3 to 5 decibels. Rachel Buxton, formerly of the US National Parks Service, argues we should go further: close roads during certain periods, reroute aircraft away from wilderness areas, limit overflights in iconic locations like the Grand Canyon.
The transition to electric vehicles offers genuine promise. Electric cars, motorboats, and ferries are significantly quieter than their combustion-engine counterparts. Sweden is already leading a market shift toward electric boats, demonstrating that change is possible at scale.
At sea, acoustic limits in marine protected areas could regulate ship noise and other underwater activities. Duarte, the ocean noise expert, champions this approach as essential for marine ecosystem recovery.
The COVID-19 pandemic offered an unexpected glimpse of what’s possible. Ocean noise dropped 20 percent during lockdowns, and wildlife responded immediately. Marine life returned to busy waterways and city shorelines. Birdsong flooded cities. Unlike chemical pollutants that linger, noise pollution vanishes the instant we stop making it. “As soon as the noise stops, then animals claim back their ancestral territory and home,” Duarte explains.
We know what needs to happen. We have the technology. We have the examples of success. The question isn’t how, but whether we have the collective will to prioritize the natural soundscape alongside physical habitat protection, because if we don’t, we’ll inherit a world where silence itself becomes an endangered species.
Source: New Scientist
