The ocean is a noisy place, buzzing with sounds created by wildlife, weather, seasons and earthquakes. For sea animals, these sounds form their natural “soundscape”, but a new article in Science shows that human influence over the past decades has drastically changed the ocean soundscape and it’s affecting marine life.
Animals that live in the oceans rely on sound to communicate and to explore their surroundings. They recognize their location by sound and produce their own sounds, for example to help them navigate, mark their territories and find a mate.
Over the years, scientists have recorded the various sounds of the ocean to create an acoustic picture of this underwater soundscape. Most of us don’t usually get to hear these ocean sounds, but several artists have been inspired by marine soundscapes and created art that interprets or incorporates some of these recordings. For example, Lindsay Olson’s “Sound in the Sea: The Art of Ocean Acoustics” is an embroidery piece inspired by sound recordings from marine researchers. And a few years ago, Jana Winderen created “The Art of Listening: Under Water”, a space for Art Basel in Miami that played underwater sounds. In a similar vein, field recordist Chris Watson has created installations where visitors could experience ocean sounds.
One striking ocean sound piece is “Luciferina”, by Francisca Rocha Gonçalves, which highlights how human sounds have been taking over the ocean soundscape.
In “Luciferina”, the noise is almost deafening. It includes sounds from underwater recordings that include noise from motors and propellers, and it shows how noise can even affect bioluminescence, which some underwater organisms use to communicate.
And while not all parts of the ocean will be that loud, a new study by Carlos Duarte and an international team of researchers and sound recording experts (including Jana Winderen, mentioned above) suggests that the extent of human noise in the ocean soundscape is widespread and that it is indeed a problem for marine life. In their review paper in Science, they describe how they’ve analysed many previous studies to create a summary of what they call “the soundscape of the Anthropocene ocean”.
Their review mentions a few of the ways that human-generated noise is penetrating the seas, including seismic surveys to detect oil and gas, scientific surveys to map geological features, fishers using technology to look for fish, navies using sonar, noise from shipping routes, traffic on bridges close to water, low-flying aircraft, construction (but not operation) of wind farms, construction (and operation) of drilling platforms, controlled detonation of old World War II bombs, and changes in the ocean soundscape as a result of human-driven climate change.
A lot of these sounds are things we rarely think about on land, but they’re making life hard for animals that rely heavily on sound to navigate or communicate. For example, one study showed that shipping noise made it more difficult for fish to avoid predators.
The researchers offer some suggestions in their paper for possible solutions. For example, they suggest that it might be easiest to start by trying to reduce the noise level of ships and construction sites than it would be to avoid activities that require sound, such as seismic surveys.
However, one of the problems they noticed was that there is very little attention for noise as a pollutant. It’s rarely mentioned in various government plans, for example. Even high-level policy plans about ocean management sometimes completely ignore the role of sound. So perhaps it’s time to take an example from some soundscape artists and pay more attention to the sounds of the sea.