A new study from Newcastle University in the UK found that the level of noise in the oceans—from drilling and piling activities, among others—is stressing and confusing European sea bass.

“Over the last few decades, the sea has become a very noisy place,” said lead researcher Ilaria Spiga. “The effects we saw were subtle changes, which may well have the potential to disrupt the sea bass’s ability to remain ‘in tune’ with its environment.”

When exposed to drilling sounds, the sea bass actively avoided the areas where the noise pollution was occurring.

The fish also showed signs of being confused when they encountered a potential predator while exposed to this underwater noise pollution. When researchers played recordings of piling sounds and mimicked an approaching predator, the sea bass failed to get away from the predator even though they made more turns.

To do their study, researchers played recordings of drilling that happened during the installation of a tidal barrage in the English Channel, and recordings of underwater piling were taken from the construction of a lifeboat station at Swansea Bay. The piling was intense, periodic noise, while the drilling was continuous noise. The researchers noted that both piling and drilling sounds overlap with the hearing range of sea bass and many other species of fish.

“Sea bass, along with other bony fishes, rely on a characteristic ‘startle and response’ mechanism to get away from predators. Exposure to underwater noise can make it harder for fishes to detect and react to predators,” Spiga explained. “It could also impair their own ability to detect food.”

More worrisome is the fact that man-made noise pollution in the oceans could affect reproduction, too. If the noise is happening near spawning grounds, for example, the fish might avoid those. It could also affect communication between fish.

The research team is calling for noise pollution standards to be expanded by proposing limits on the amount of time underwater drilling and piling can take place. They also suggest replacing piling with drilling so the fish have time to recover from the stress that noise pollution induces in them.