Ocean acidification has become one of many consequences of our modern civilization that potentially could cause major changes to Earth’s undersea environments. There are several physical and chemical effects from acidification, one of which affects the undersea acoustic environment. There are various empirical models for acoustic absorption, but an empirical model by Francois and Garrison has a pH dependent contribution. As the ocean becomes more acidic, the pH decreases from its current value and the model predicts a reduction in the amount of acoustic absorption. The result of this absorption reduction changes the overall transmission loss of sound propagation and makes the underwater environment a “louder” place. The consequences of which would be minor complications to ocean exploration but will have a greater impact upon the undersea fauna. As the environment becomes louder, those animals that use acoustics to echolocate food, will find it more difficult to do so and others may find the environment to not be amenable to their survival. These changes are occurring on a time scale on the order of decades, so environmental acoustic monitoring of ambient conditions and large-scale migration can be utilized as an indicator of the changes to the water space.
Eastland G., 2023. Ocean acidification: future effects to ocean environments and biologic response. The Journal of the Acoustical Society of America 153: A62. doi: 10.1121/10.0018165. Article (subscription required).
