Talk about noisy neighbors! The mating calls from the gathering of a species of Mexican fish are loud enough to temporarily deafen marine mammals — but scientists say the fish themselves may be threatened.
Millions of adult Gulf corvina gather every year between February and June in Mexico’s Colorado River Delta to spawn, and the sounds they produce are among the loudest wildlife events ever recorded, according to a recent study in Biology Letters. Their mating calls, which have been compared to a machine gun, can temporarily and even permanently deafen nearby marine mammals, including sea lions and dolphins.
Listen below to hear the sound of a single fish swimming by over the roar of others in the background:
Marine scientists spent time observing the fish with underwater microphones and sonar, recording individual calls as loud as 177 decibels. The chorus of all the fish gathered together is loud enough to be heard through the hull of a boat.
But their impressive talents may be hurting them.
The Gulf corvina is a popular menu item, and when the entire population gathers on a yearly basis, so do the fishing boats. A single vessel can catch up to a ton of the fish at a time, according to a statement released by the University of Texas at Austin.
The International Union for the Conservation of Nature has listed the fish as “vulnerable” to extinction. It’s hard to estimate their precise numbers due to the fact they can’t be seen through the incredibly murky waters where they gather, and the cacophony makes it hard to distinguish individuals. But scientists have evidence that the fish are getting smaller in size — a sign that could indicate overfishing.
Now, researchers from The University of Texas Marine Science Institute (UTMSI) and the Scripps Institution of Oceanography at the University of California San Diego have figured out how to estimate their numbers simply by listening to their calls, providing data that could help fisheries monitor the population and design a conservation plan.
“A precautionary approach should be adopted by fisheries managers to ensure that this wildlife spectacle does not disappear,” states study co-author Timothy Rowell.