An ocean of noise is having major impacts on the marine environment

Human pollution is changing the way sound works in the ocean, muffling out natural sounds marine marine animals use to mate, communicate and navigate.

There are two ways this is happening. 

According to a new study in the journal Proceedings of the Royal Society B, ocean acidification — caused by ocean waters taking up excess carbon dioxide from fossil fuel emissions — may be making it more difficult for fish to hear.

Craig Radford, an associate professor of marine sciences at the University of Auckland in New Zealand, is the lead author of the study. He found the more acidic the water is that the fish grew up in, the worse its hearing becomes. 

That means the juvenile snapper fish he studied that spawn out in the ocean might not be able to find their way back to the reef if they can't hear as well. 

And at the same time the ocean environment is becoming a noisier and more difficult environment in which to hear, largely due to human noise pollution.

Humans produce a vast amount of ocean noise, from sources like commercial shipping, navy sonar activity and seismic oil, gas and geological exploration.  

In a recent review paper in the journal Science, marine scientists called for urgent international action to curb underwater noise pollution, which they wrote has become "the neglected elephant in the room of global ocean change." 

Francis Juanes, the Liber Ero Chair for Fisheries Research at the University of Victoria in British Columbia and senior author of the paper, described the extent of the "soundscape of the anthropocene ocean" — as they call it in their paper.

He said the volume of shipping noise alone has increased 32-fold in the last 50 years. 

You can listen to ocean soundscape and interviews with Craig Radford and Francis Juanes, at the link above.

Produced and written by Sonya Buyting