Motorboat noise gives predators a deadly advantage

February 5, 2016, University of Exeter
The predatory dusky dottyback eyeing up a juvenile Ambon damselfish. Credit: Chris Mirbach

The rate that fish are captured by predators can double when boats are motoring nearby, according to pioneering work led by a University of Exeter marine biologist.

Dr Stephen Simpson and his international research team found that noise from passing motorboats increases stress levels in young and reduces their ability to flee from predators. As a consequence they are captured more easily and their survival chances are halved.

This is the first study to show that real-world noise, in this case the common noise of motorboats, can have a direct consequence on survival. The team hope the findings will inspire better environmental noise management in coastal areas.

"We found that when real boats were motoring near to young damselfish in open water, they became stressed and were six times less likely to startle to simulated predator attacks compared to fish tested without boats nearby," said Dr Simpson, a senior lecturer in the University's Biosciences department, whose work is funded by the Natural Environment Research Council (NERC) and the ARC Centre of Excellence for Coral Reef Studies.

"The combination of stress and poor responses to strikes by predators is why these fish became such easy prey," said collaborator Dr Andy Radford, University of Bristol.

The research team recording motorboat noise at the experimental site. Boat driver: Mark Meekan; Recording: Steve Simpson Credit: Maud Ferrari

The team of scientists, which included Australian and Canadian researchers specialising in predator¬-prey interactions and bioacousticians from the University of Bristol, combined laboratory and field experiments, using playbacks and real boat noise, to test the impact of motorboat noise on survival of young Ambon damselfish during encounters with their natural predator the dusky dottyback.

Rather than being despondent, the team is optimistic about the possibilities for management of noise and its potential impact. "If you go to the Great Barrier Reef, there is a lot of noise from motorboats in some places. But unlike many pollutants we can more easily control noise. We can choose when and where we make it, and with new technologies, we can make less noise. For example, we could create marine quiet zones or buffer zones, and avoid known sensitive areas or times of year when juveniles are abundant," said Dr Simpson.

Managing local environmental stressors such as noise is an essential first step in protecting the marine environment. "You might argue that climate change is a bigger threat to reef life, but if we can reduce the effect of local noise pollution we build greater resilience in reef communities to looming threats such as global warming and ocean acidification," said collaborator Dr Mark Meekan, Australian Institute of Marine Science.

Anthropogenic increases fish mortality by predation by Stephen D. Simpson, Andrew N. Radford, Sophie L. Nedelec, Maud C. O. Ferrari, Douglas P. Chivers, Mark I. McCormick, Mark G. Meekan is published in Nature Communications.

Explore further: Stress from noise can be short-lived

More information: Stephen D. Simpson et al. Anthropogenic noise increases fish mortality by predation, Nature Communications (2016). dx.doi.org/10.1038/ncomms10544

Related Stories

Stress from noise can be short-lived

January 28, 2016

Underwater noise can negatively impact anti-predator behaviour in endangered eels and increase stress in both eels and European seabass, a new study published in Royal Society Open Science confirms.

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, ...

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

Scale-eating fish adopt clever parasitic methods to survive

January 17, 2018

Think of them as extra-large parasites. A small group of fishes—possibly the world's cleverest carnivorous grazers—feeds on the scales of other fish in the tropics. The different species' approach differs: some ram their ...

How living systems compute solutions to problems

January 17, 2018

How do decisions get made in the natural world? One possibility is that the individuals or components in biological systems collectively compute solutions to challenges they face in their environments. Consider that fish ...

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.