Marine noise pollution stresses fish out

Aug. 10 (UPI) -- New research suggests fish are becoming stressed and confused as a result of growing underwater noise pollution.

Scientists at Newcastle University measured the stress levels of European sea bass while replicating the types of piling and drilling sounds heard during underwater construction projects. They found the fish were made anxious and uncomfortable by the noise pollution.

When they coupled drilling sounds with the simulation of an approaching predator, scientists found sea bass were less effective at fleeing. The findings -- detailed this week in the journal Marine Pollution Bulletin -- suggest fish are less in tune with their surroundings when loud, foreign noises invade their soundscapes.

"Over the last few decades, the sea has become a very noisy place," researcher Ilaria Spiga said in a news release. "The effects we saw were subtle changes, which may well have the potential to disrupt the seabass's ability to remain 'in tune' with its environment."

In addition to making fish more vulnerable to predators, researchers worry noise pollution could interfere with fishes' ability to find food and mates.

"If fishes actively avoid areas where these sounds are present it could prevent them from entering spawning grounds, or affect communication between individuals," Spiga said.

The piling and drilling noises used in lab experiments were recorded from actual marine construction projects. Scientists say offshore infrastructure projects, shipping and onshore activities can all contribute to noise pollution.

Previous studies have highlighted how noise pollution can disrupt the communication and navigation abilities of whales and dolphins, but the latest study serves as a reminder that underwater noise can be disruptive for a variety of marine species.