Ocean acidification turns up the volume

What was that? Can’t hear me? Don’t worry, ocean acidification will fix that.

According to a new paper published in Nature Geoscience, as the oceans become more acidic through increased atmospheric CO2, the changes in seawater chemistry will result in fewer reactions and less acoustic used. This means that sound will travel further, and therefore be louder at a fixed distance than under less acidic conditions.

Sound absorption attenuation as a function of frequency and seawater pH (Ilyina et al 2010)

The authors predict that by 2100, sound absorption could fall by up to 60% high latitudes regions of the world. Most of the absorption of sound occurs at low frequencies (1,000 to 5,000 hertz) – the same range as propellor noises, ship sounds and military sonar. Marine noise is a huge issue in the oceans, and is already known to harm cetaceans (‘i’m beached as, bro‘) – and this is projected to get louder and louder:

Temporal evolution of seawater pH and sound absorption coefficient in acoustic hotspots (Ilyina et al 2010)

“We’re not saying that during the next 100 years all dolphins will be deafened,” Dr. Zeebe said. “But the background noise could essentially override or mask the sounds that they’re depending on.” (Read More)

Ilyina et al (2010) Future ocean increasingly transparent to low-frequency sound owing to carbon dioxide emissions Nature Geoscience (3)18-22

Leave a Reply

Your email address will not be published. Required fields are marked *