Wednesday, August 27, 2014

27/08/2014: pH increases threaten our marine environment

As carbon dioxide in the atmosphere rises, a proportion will be  absorbed by the sea. In 2014 over 2.5 billion tonnes of the stuff will make this transfer into the sea

As the sea covers over 70 percent of the globa's surface the opportunity for the atmosphere to react with seawater is significant and wherever this takes place there is an exchange.

In the past there has been an acceptable 'balance' in this exchange, however in recent times an imbalance may be occurring which can be traced back to the start of the industrial revolution. If more carbon dioxide is in the atmosphere and then increases the exchange with the oceans, meaning more goes in than is naturally taken out,

With an annual increase of over five percent entering the atmosphere, this means that the concentration today has reached more than 400ppm; higher than at any time over more than 800,000 years.

pH is a measure of the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH very close to 7.

The extra CO2 exchange means the oceans have already decreased from 8.2pH by 0.1 which means that seawater is now some 30% more acidic than in 1800.

What does that mean to marine life? That's the question that John Lawrence addresses in his article on ocean acidification. He says that if it's business as normal and surface pH drops to 8.0 by 2050 and to 7.8 - a tipping point - by 3000 our seas will be some 150% more acidic and that could have catastrophic outcomes for marine life.

Reading the full story
HERE is well worthwhile!

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
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