The National Oceanic and Atmospheric Administration is asking for public comment on guidelines updating the effects of human-made sounds on marine mammals.
Marine mammals rely on their sense of sound for survival. “They use it for feeding, locating mates, and just generally understanding what’s going on in the world around them,” says NOAA fisheries biologist Amy Scholik-Schlomer, who is also an acoustic specialist.
She says the guidelines update the levels at which human-made sounds affect marine mammals temporarily and permanently. NOAA calls these threshold shifts. A marine mammal experiencing a temporary threshold shift is like going to a rock concert. “Your hearing is temporarily affected but it fully recovers, while permanent threshold shift would be something that your hearing is affected but it doesn’t fully recover. You have some permanent loss. It doesn’t mean you’re deaf and it doesn’t mean that it affects your entire hearing range; it just means that you can’t hear quite as well as you could before,” Scholik-Schlomer explains. Read more