We know that water pollution can harm the ability of fish to reproduce. But noise?
Yes, noise pollution can as well, according to scientists at the University of Auburn who looked at blacktail shiners spawning in tributaries of the Chattahoochee River.
To attract mates, male shiners emit bursts of sounds, similar to a cat’s purr, and, to help protect eggs in the nest, they make popping sounds that warn away intruders. They do so in streams that already are “noisy” with water flowing over rocks and down small waterfalls.
And nearby road traffic noise can mask shiner communication even more, reported Daniel Holt and Carol Johnston in Biological Conservation.
Using hydrophones, the researchers determined that the shiners, similar to other species, have developed an ability to communicate via a “quiet window” in the spectrum of natural noise. But road traffic noise, especially trucks crossing nearby bridges, overlap that window and potentially drown out the fish talk as far as 12 kilometers away.
“In order for an acoustic signal to be an effective source of communication, the signal must be successfully detected and interpreted by the intended receiver. One potential barrier to acoustic communication is background noise,” the scientists said.
“Our calculations suggest that road traffic noise propagates to an extent that virtually entire watersheds are impacted by this noise pollution, especially in urban areas.”