Scylla and Charybdis (Thoughts & Review on “Sonic Sea”)

In recent years, scientists have made many discoveries in terms of studying sound and its relations to the ocean. One such study showed that a noise made deep in the heart of the Indian Ocean could travel through the murky waters of the Pacific, to as far as the West coast in the United States. Researchers tracked and detected the noise, using hydrophones to detect the noise along the coast of Washington state.

In short, sound travels through water extremely efficiently – as efficiently as light travels through air. With that in mind, research has found that the amount of sound in the ocean has increased dramatically in the last five decades. From freight ships to cruises to the many sonar mapping systems used by private companies and the government alike, our oceans have become flooded with human-made noise. And, as a result, the marine life that relies on echo location and auditory senses have suffered greatly.

Dolphins, whales, and some types of fish use sound as a means to communicate, to hunt, and to reproduce. With all of the white noise filling their seas, it has become increasingly difficult for any of these animals to do this.

One study followed the diet of a group of whales in the Atlantic, collecting fecal samples to analyze for certain chemicals and hormones. In this study, the concentration of stress hormones was relatively high throughout the study, which spanned several years. However, around 2001, the levels of stress hormone documented in whale feces began reducing significantly. The numbers all began declining sharply after 9/11. Conclusively, the reduced freight traffic following 9/11 and the subsequent reduction of human noise polluting the ocean led to lower levels of stress in the whales. In other words, the amount of stress hormone in whales correlated with the amount of machinery traffic in the ocean.

The film Sonic Sea presents case after case, study after study, of marine wildlife adapting poorly to the noises humans are dumping in the ocean.

But what is there to do with this knowledge? Stopping mass transportation of people and produccts by sea is near impossible; over 90% of the world’s transportation occurs by sea. Stopping industry on the seas altogether would be an inefficient and impractical way to help marine life.

Instead, there are many other ways to solve this problem. Better technology to replace destructive seismic airguns and noisy ships would reduce the noise pollution in our oceans. Unlike chemical pollution or other damaging human by-products, “noise pollution disappears once you stop making it,” making it entirely possible for our oceans to become serene once more.



Sources:

Sonic Sea. Dir. Michelle Dougherty and Daniel Hinerfeld. 2016. Film.