Turning Down the Noise to Save Our Oceans

KAUST Professor Carlos Duarte is leading global efforts to understand and mitigate ocean noise pollution

There is growing awareness of how environmental noise impacts human health. According to estimates by the World Health Organization, noise from cars, trucks, airplanes and trains can cause or exacerbate existing ailments such as tinnitus, sleep disturbances, obesity, diabetes and ischemic heart disease, resulting in an annual loss of 1 million healthy years of life in Western Europe alone.

Some experts have warned that it could be the next big public health crisis for humans, while biologists have shown that noise can significantly impact animal populations as well – preventing birds from migrating, for example. Far less attention has been given to the impact that anthropogenic (or man-made) noise has on our oceans, where roughly 80% of the world’s merchandise is transported along routes shared with whales, fish and a wide array of other maritime species.

Led by KAUST Distinguished Professor of Marine Science Carlos Duarte, a global team of scientists is working to understand how anthropogenic noise impacts marine life and what policy interventions can be implemented to mitigate its effects.

Humans often assume that the ocean is silent because we do not hear well underwater due to the way our ears function, but sound travels far – and quickly – underwater. Marine animals are sensitive to sound, which they use as a prominent sensorial signal to guide many aspects of their behaviour and ecology. As such, the rise in anthropogenic noise from cargo shipping, seismic blasting, active sonar, pile-driving and fishing vessels has been detrimental to marine wildlife. Ocean noise pollution can disrupt their behaviour, physiology, reproduction and – in extreme cases – end their lives.

Whales have been found washed up with ears bleeding from decompression injuries caused by anti-submarine-warfare training. Sonar emitted by submarines and other vessels has been shown to frighten whales or cause them to panic and leave their foraging areas. Anthropogenic noise also impacts the vocalizations whales and other marine mammals use to communicate, find food and locate one another.

In a multi-institutional meta-study published in Science in February 2021, Professor Duarte and researchers from a host of countries – including Denmark, the US, the UK, Australia, New Zealand, the Netherlands, Germany, Spain, Norway and Canada – document the adverse effects of humanity’s sonic footprint, and present a path toward solutions in a context of ocean health and sustainable ocean economies.

Reviewing over 10,000 papers, the researchers concluded that ocean noise interferes with how marine animals hear, communicate and respond to the ecological processes they depend on for survival. Mitigating the impacts of noise from human activities on marine life is therefore key to achieving healthier oceans and deserves to be prioritised alongside factors such as pollution, climate change and overfishing.

UNIVERSITY OF CALIFORNIA, SANTA CRUZ

“If we can reduce noise from the list of other stressors impacting marine animals, then that is going to give them a better chance to survive.”

Dr. Daniel Costa, Director of the Institute of Marine Sciences at the University of California, Santa Cruz

While the paper extensively documents the impacts of anthropogenic noise on the ocean, it also highlights solutions, many of which have already been tested and provide a suite of benefits for the ocean and companies alike. Unlike other anthropogenic impacts such as plastic pollution or carbon emissions, noise pollution is easier to remedy. When noise stops, the problem more or less immediately goes away, and ecosystems and organisms can begin to repair. According to the researchers, if just 15% of the total number of merchant and fishing vessels adopted noise-reduction technologies, it would go a long way toward reducing the impact of ocean noise on marine wildlife.

Cargo ships and fishing vessels are the main culprits of ocean noise pollution, generating long-carrying, low-frequency sounds that can be heard kilometres away by many different marine animals. Maersk, the world’s largest maritime logistics company, has already installed noise-reduction propellers on five of its largest container vessels. As a result, the company’s vessels are both quieter and more energy efficient – a win-win scenario that lowers transportation costs as well as greenhouse gas emissions for the firm.

The study has already generated widespread public interest across various prominent international news outlets, and was ranked by the prestigious journal Nature as the most-popular scientific article among hundreds of thousands published in February 2021. Professor Duarte, who serves as a subject expert on the UN’s High-Level Panel for a Sustainable Ocean Economy, believes the timing of the paper is conducive to international discussions that could be translated into healthy ocean policies. KAUST’s role within this debate underlines the Kingdom’s commitment to the conservation and sustainable use of our oceans, as outlined in the Vision 2030 agenda.

CARLOS DUARTE Distinguished Professor of Marine Science and Tarek Ahmed Juffali Research Chair in Red Sea Ecology

THE EU RECOGNIZES THE OCEAN SOUNDSCAPE AS AN INTEGRAL COMPONENT OF OCEAN HEALTH, AND REGULATES OCEAN NOISE AND ITS EFFECT ON MARINE MAMMALS AND ECOSYSTEMS. OUR HOPE IS THAT THE SCOPE OF ISSUES AND EVIDENCE PRESENTED IN THE PAPER, TOGETHER WITH THE PROPOSED MITIGATION ACTIONS, WILL COMPEL OTHER COUNTRIES TO RESPOND.