Could the Sounds of Cod Having Sex Save a Species (and an Economy)?

Spying on “spawning haystacks” is helping fishermen make more money and biologists preserve a floundering fish population

Rick Price/CORBIS

The thought of a school of cod getting it on (and making plenty of grunting, thumping sounds during their sexytimes) might sound weird, irrelevant or just plain embarrassing. But to a team of fishermen and scientists, it’s a sweet sound indeed. In fact, reports NPR’s Christopher Joyce, the underwater sounds of mating cod could just save a species — and an entire fishing economy.

Joyce explains that in response to a growing cod crisis in Massachusetts, an unusual team is using “cod grunting” to find the fish and achieve two very different purposes. Fishermen looking to increase their revenues want to avoid fishing for cod since catch limits are so low, reports Joyce. Biologists’ are trying to preserve the quickly-dwindling cod population. Both want to find the fish, either to avoid or to study them. 

When biologists from the National Oceanic and Atmospheric Administration learned that they could detect repetitive grunts during cod season, they decided to try to track the fishes’ spawning calls. To do so, they set out on a mission to find the center of cod’s sexy vocalizations: “spawning haystacks.”

NOAA writes that during spawning season, male cods grunt in patterns that could be either a form of courtship or a warning to predators. To find and protect mating cod, though, they needed to find the haystacks in which cod group, get it on, and grunt audibly (if they’re not disturbed by boats or other forces first).

“But pinpointing the haystacks was kind of like finding a needle in the ocean,” writes Joyce. That’s where the fishermen come in. Call it a win-win: by leading biologists to spawning cod, fishermen are better able to avoid them and focus on more lucrative endeavors without running into profit-cutting fishing limits. There’s no word if the cod appreciate a bit of privacy while they have sex, but biologists hope that with the information they’re able to gather about cod mating, they’ll be able to better preserve their habitat.