[The Global Growl](https://hakaimagazine.com/features/quieting-the-global-growl/) is a term for the background noise caused by large ships and its impact on marine life. As a form of [[Environmental Noise]] it may affect whales and other marine life. However, this isn't just limited to engine noise; noise from [[Sonar]], seismic testing, and construction are other sources of underwater noise. The article notes that underwater noise also comes from cavitation around propellers > Much of the underwater noise from ships comes from propellers, or more specifically, from bubbles that form on the propeller’s edges.