Tuesday, February 5, 2013

Acidification of our Oceans

For many years climatologists and environmentalists have been warning that the future of our marine life is in danger, with changes in weather patterns, rising and decreasing sea levels and global climate change.

One such warning has been around carbon dioxide emissions causing ocean acidification. Carbon dioxide is absorbed into the water causing acidification of the sea, and is absorbed more quickly in colder waters. Acidification affects marine life’s ability to reproduce, form protective shells and growth. It kills our reefs, and is threatening all marine life.

New research has shown that acidification of the oceans will also see low frequency sounds/acoustics travel twice as far in the ocean as they currently do. Acidification of our oceans has researchers claiming that our waters will soon resemble ocean acoustics of more than 110 million years ago (dinosaur times).

The mechanism that would drive this change is a shift in the low frequency absorbing boron reaction that occurs in the ocean and is pH-dependent. As pH increases, the boron reaction and absorption of low frequency sound waves decreases—allowing those sounds to travel further, according to David Browning, an Acoustic Researcher (1)
One such species that relies on the ocean’s acoustics to communicate are our whales. Sperm whales communicate through a series of clicks and humpbacks are renowned for their melodic songs. How the low frequency acoustics will affect their communication and natural way of life is yet to be understood.

Ocean acidification has led to much worse than just changes in acoustics in the past – ocean acidification has been the cause of extinction of species around the world.
Even if all carbon emissions stopped today, it will take thousands of years for the oceans to recover. However, action now can prevent conditions that are corrosive to calcifying organisms, from becoming more widespread (2).

1) http://www.redorbit.com/news/science/1112716391/ocean-acoustics-acidification-101912/
2) http://www.antarctica.gov.au/about-antarctica/fact-files/climate-change/ocean-acidification-and-the-southern-ocean
Further Reading
• redOrbit (http://s.tt/1qwhZ)
Photograph by Lou Dematteis, Human Voices Now - courtesy of http://oceanacidification.wordpress.com/2009/09/10/photographs-and-video-from-the-alaska-acid-ocean-sos/

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