In our July-August issue, Judith Lewis reports on the plague of ocean noise that’s taking a toll on marine mammals throughout the world’s oceans.
Where does the ruckus come from? Industry: seismic air guns that petroleum outfits use to sound the depths for oil-rich pockets, acoustic deterrent devices fishing operations rely on to warn marine mammals away from their nets, and the sonar used by military and other vessels for underwater communication.
Michael Stocker, director of the Lagunitas, California–based advocacy group Ocean Conservation Research, explains that for a whale the sounds of technology may be like “somebody following you around all day running their fingernails down a blackboard.”
Take a listen to the industrial and natural sounds below to make your own comparisons.
The Ocean’s Industrial Racket
These two types of communications sonar are used to communicate underwater with remotely operated vessels, submarines, and other equipment.
M Sequence Communications Sonar
Arrays of airguns are used for seismic surveys, especially by petrol companies looking for oil. Blasts of compressed air create impulses that hit the ocean floor and are picked up again by hydrophones to give a reading of what’s beneath the ocean floor.