A Sound Environment

While most of us recognize the oceans as the largest ecosystem on Earth, fewer of us realize that this massive realm (containing 97% of the planetary water) is also full of sound. This sound is created by sources as diverse as underwater volcanoes, sliding tectonic plates, singing whales, and droning ship propellers. Moreover, the mix of sounds detected in the ocean differs as a function of location and depth, owing to the peculiar way that sound bounces around the oceanic depths (often confining itself to discrete channels). The physical properties of seawater (e.g., temperature and salinity), along with the seafloor topography, serve to fine-tune the oceanic symphony. So, who’s listening? Well, most marine creatures rely more on sound or subtle vibration than they do on vision because seawater transmits pressure waves more efficiently than light waves. We landlubbers still have a lot to learn about this symphony