Man-made noise makes fish more susceptible to predators

August 6, 2014
A school of sardines in Italy. Credit: Wikimedia / Alessandro Duci

Despite their reputation as slippery customers, a new study has shown that eels are losing the fight to survive when faced with marine noise pollution such as that of passing ships.

Scientists from the Universities of Exeter and Bristol found that fish exposed to playback of ship noise lose crucial responses to predator threats.

The study, published today in the journal Global Change Biology, found European eels were 50% less likely to respond to an ambush from a predator, while those that did had 25% slower reaction times. Those that were pursued by a predator were caught more than twice as quickly when exposed to the noise.

Lead author Dr Steve Simpson, Senior Lecturer in Marine Biology & Global Change at the University of Exeter, said: "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 behavioural responses. If these impacts affect whole populations then the endangered eel, which has seen a 90% 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."

To understand what may cause this loss of crucial anti-predator behaviour, the team also tested physiology and spatial behaviour, and found heightened stress levels (increased ventilation and metabolic rate) and reduced lateralised behaviour (right-left preferences) when eels were subjected to of ship noise.

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

This study highlights the importance of assessing the scale of impacts of the anthropogenic noise that now pervades many coastal environments. Dr Simpson said: "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 sources."

Explore further: Ship noise makes crabs get crabby

More information: 'Anthropogenic noise compromises anti-predator behaviour in European eels' by Steve Simpson, Julia Purser and Andy Radford is published in Global Change Biology.

Related Stories

Ship noise makes crabs get crabby

February 26, 2013

A study published today in Biology Letters found that ship noise affects crab metabolism, with largest crabs faring worst, and found little evidence that crabs acclimatise to noise over time.

Boat noise stops fish finding home

June 28, 2013

(Phys.org) —Boat noise disrupts orientation behaviour in larval coral reef fish, according to new research from the Universities of Bristol, Exeter and Liège. Reef fish are normally attracted by reef sound but the study, ...

Species matters in a noisy world

March 4, 2014

Fish exposed to increased noise levels consume less food and show more stress-related behaviour, according to new research from the University of Bristol and the University of Exeter. However, the way fish decreased their ...

Noise pollution impacts fish species differently

July 24, 2014

Acoustic disturbance has different effects on different species of fish, according to a new study from the Universities of Bristol and Exeter which tested fish anti-predator behaviour.

Boat noise impacts development and survival of sea hares

July 31, 2014

While previous studies have shown that marine noise can affect animal movement and communication, with unknown ecological consequences, scientists from the Universities of Bristol and Exeter and the École Pratique des Hautes ...

Recommended for you

Research advances on transplant ward pathogen

August 28, 2015

The fungus Cryptococcus causes meningitis, a brain disease that kills about 1 million people each year—mainly those with impaired immune systems due to AIDS, cancer treatment or an organ transplant. It's difficult to treat ...

Genomes uncover life's early history

August 24, 2015

A University of Manchester scientist is part of a team which has carried out one of the biggest ever analyses of genomes on life of all forms.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.