For Southern Resident killer whales, which live in the Haro Strait between Victoria, British Columbia, and Seattle, sound is the foundation of their culture.
But this fundamental reliance on sound is why noise pollution can be devastating for whales, especially for a critically endangered species that is suffering from other threats. The population of Southern Resident killer whales has shrunk to just 85 individuals. The threats they face are myriad. The salmon that make up most of their diet have declined dramatically because of logging, which warms and silts spawning streams. Fish farms allow diseases to fester, and cities and farms divert and pollute streams. High levels of persistent organic pollutants introduced by humans also contaminate the whales.
Killer whales’ world has shrunk because of ship noise
Noise could be the final straw, said Williams. Itās not just intense, episodic noise from naval operations or industrial activity that can drive whales to beach themselves. Daily ship traffic, especially the gargantuan cargo vessels that bring us the vast majority of everything we wear, use, and eat are also harming whales and other marine life.
āThere are places now, especially in the Northern Hemisphere, where the background noise level is 100 to 1,000 times above what it would be normally,ā said Clark. āAnd itās chronic.ā
āMedian noise levels are high enough to cause killer whales to lose 62 percent of their ability to communicate with each other,ā said Williams. āWhen it gets extremely noisy, when thereās lots of ship traffic, that rises to 97 percent.ā
