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Man-made noise is killing fish by making them more susceptible to predators, according to a new study.

New research from the Universities of Exeter and Bristol revealed that exposure to noise pollution from passing ships lowers eels' ability to defend themselves against predators.

Researchers found that European eels were 50 percent less likely to respond to attacks from predators. Furthermore, those that did respond had 24 percent slower reactions times than those not exposed noise pollution. What's more eels were caught more than twice as quickly when exposed to nose.

"Our findings demonstrate that acute acoustic events, such as the noise of a passing ship, may have serious impacts on animals with direct consequences for life-or-death behavioral responses. If these impacts affect whole populations then the endangered eel, which has seen a 90 percent crash in abundance over the past 20 years due to climate change, may have one more problem to deal with as they cross busy coastal areas," Lead author Dr. Steve Simpson, Senior Lecturer in Marine Biology & Global Change at the University of Exeter, said in a news release.

In the study, researchers tested physiology and spatial behavior and found that eels exposed to recordings of ship noise experienced heightened stress levels and reduced lateralized behavior.

"The fact that eels were affected physiologically and spatially suggests that other important functions may also be affected. We focused on anti-predator responses as, unlike impacts on movement or feeding, there is no way to compensate for being eaten after the disturbance goes away," co-author Dr Andy Radford, Reader in Behavioral Ecology at the University of Bristol, said in a news release.

"If we want to effectively manage noise in the marine environment, we next need to assess the spatial scale over which individual animals and populations are affected. This means taking experiments like this one to offshore environments near to real-world noise sources," said Simpson.

The findings are published in the journal Global Change Biology.