AUDIO: This Is What Ultra Sounded Like To Fish

Even though there were large physical barriers to block sound from the Ultra Music Festival from disturbing fish, newly released audio recordings reveal the concert’s pounding dance beat was clearly audible to toadfish in tanks at a research lab right next to the Virginia Key concert site.  

The microphones captured an almost ethereal sounding version of Ultra, with an audible beat. You can listen for yourself here:

Researchers at the University of Miami Rosenstiel School of Marine and Atmospheric Science used a hydrophone, or underwater microphone, before and during Ultra. They recorded a 7 to 9 decibel increase in sound, and a related increase in stress hormone levels — higher than those taking place when a toadfish is chased by a bottlenose dolphin, a toadfish predator.

But what about fish in the open ocean?

Another hydrophone located under the Bear Cut Bridge found an increase of 2 to 3 decibels associated with Ultra, which came as a surprise, researchers said.

“I wasn’t expecting to hear anything” from Ultra, said professor Claire Paris, a biological oceanographer at the Rosenstiel School.

That’s because the spot where the microphone is located, on an underwater bridge structure, gets saturated with a lot of other undersea noise — everything from the automotive traffic on the bridge to fast rushing underwater currents to jet skis and other marine traffic.

She said that while the Ultra-related sound increase may seem small, it happened to be at the very frequencies where fish are most sensitive to noise.

“I don’t know what (the noise) does to them,” Paris said. “That would take additional experiments.”

Another unknown is how the sound affected fish at the nearby Miami Seaquarium, where both fish and marine mammals were exposed to the concert sound. “It’s a fair question,” said Paris.

Although Ultra is not coming back to Virginia Key, future music concerts are expected, as the long-defunct Marine Stadium is being refurbished. Establishing a biologically-safe specification for both the hatchery and fish in the open water remains a priority, said lead investigator Martin Grosell,  professor of marine biology and ecology and Maytag Chair of Ichthyology.

“There has never been anything like the scale of their concert” near the lab, he said. Although he said Ultra complied with their promised noise specifications, they might not be sufficient for any future event.

“Just because they played nice doesn’t mean we didn’t suffer from that event,” Grosell said.