By John R. Platt
It's a rare scientific paper that cites both biologist E.O. Wilson and AC/DC guitarist Angus Young.
In fact, there's only one paper with that distinction: Testing the AC/DC hypothesis: Rock and roll is noise pollution and weakens a trophic cascade, published this week in the journal Ecology and Evolution.
As you might guess from the title, the study—by ecologist Brandon T. Barton and other researchers from Mississippi State University—takes its cue from the famous AC/DC song Rock and Roll Ain't Noise Pollution as an avenue to reveal the actual effects of anthropogenic noise (musical or otherwise) on species and their ecosystems.
Here's the refrain from that song, which AC/DC released on their album Back in Black in 1980.
Rock 'n roll ain't noise pollution
Rock 'n roll ain't gonna die
Rock 'n roll ain't noise pollution
Rock 'n roll it will survive (yes it will)
So what was the effect of this music on natural systems? Not so rockin', as it turns out. The researchers fired up their boom boxes and blared music by AC/DC, Guns N' Roses and other hard-rocking bands (as well as a few less musical urban noises, like jackhammers) at some soybeans and their accompanying aphids (a pest insect) and ladybugs (which normally eat the aphids). During a two-week trial—in which Back in Black was played on a continuous 24-hour loop—the ladybugs became less effective predators and ate fewer aphids. This meant there were 40 times more aphids to consume the soybean plants, resulting in plants that were 25 percent smaller.
In other words, rock 'n roll may survive, but the plants exposed to it were less likely to.
Now, this is about a lot more than AC/DC. The rock music may be the novel part of the experiment, but the most interesting tests were the ones using more urban noises, which were played at roughly the same volume as traditional farm equipment like tractors and combines. Those tests had the same effect on the ladybugs and aphids, which reveals the real-world consequences of anthropogenic sound. "Farm noise could actually reduce the efficiency of natural predators at controlling pests," Barton said in a press release. "If that happens and the pests take off, you might have to spray more chemicals. So it could be a soundscape that's influencing how many chemicals we have to use because it changes the efficiency of the predator."
This is just the latest study that shows human-generated noise is causing trouble for ecosystems. A 2016 study found that the noise from natural-gas extraction sites robs owls of their ability to hunt. Another study published last year found that engine sounds from highways diminished the ability for nearby animals to find prey (or, conversely, to avoid predators), even when the animals live in parks and other protected areas. A study published earlier this year found that birds living near natural-gas well are experiencing PTSD-like symptoms.
What sets this new experiment apart, as Barton wrote in an essay for The Conversation, is that previous studies looked at the direct effect of noise on specific species. Here, the soybean plants weren't themselves harmed by the music, but their ladybug protectors were. "Animals don't live in isolation," Barton wrote. "They're embedded within a tangle of food web interactions with other species. So by affecting even one species, noise pollution—or any other environmental change—may generate indirect effects that spread from individual to individual, and eventually may affect entire communities."
As for the communities affected by their study, the researchers do offer their apology to AC/DC for proving that "in some contexts, rock and roll is noise pollution." They also, however, thank the band for their contribution to the work, which led to one of the more interesting acknowledgment sections I've seen in a recent scientific paper: "We thank B.F. Johnson, A.M. Young, M.M. Young, C. Williams, P.H.N. Rudd, and R.B. Scott for inspiration and motivation to conduct this research. This work is dedicated to the memory of M.M. Young, who passed away during the preparation of this manuscript."
Ah, science: One more way rock 'n roll will survive (yes it will) and live forever.
Now turn down the music, kids. There are some ladybugs doing important work over here.
Reposted with permission from our media associate The Revelator.