Seismic Surveys and MPAs: How Should Managers Address the Issue of Underwater Noise?

But over the past 150 years, the noise levels in our oceans have increased significantly. This is due to human activity. The propeller noise from shipping has raised the baseline for low-frequency ambient ocean sound worldwide. There is noise produced by undersea construction, such as pile-driving (e.g., hammering posts into the seafloor, such as for docks or drilling platforms). Sonar is used to map the ocean bottom or (for naval defense purposes) to scan for submarines. And airguns are used in seismic surveying: exploring the geologic substructure of the seafloor by sending sound energy into the ground and analyzing the returned energy.