Thursday, October 03, 2013

Researchers Find Historic Ocean Acidification Levels: ‘The Next Mass Extinction May Have Already Begun’

I guess that is on top of the already on-going mass extinctions caused by human action, including global warming and habitat loss.

You might remember from science classes that more colder water can hold more of a gas than warmer water. That is why water boils when it is heated - the gas is coming out of solution.

By Katie Valentine on October 3, 2013

The oceans are more acidic now than they’ve been at any time in the last 300 million years [300,000,000], conditions that marine scientists warn could lead to a mass extinction of key species.


Acidification causes major harm to marine ecosystems, especially coral, which has a hard time building up its calcium carbonate skeleton in acidic water. Coral reefs serve as nurseries to many young fish, so they’re essential both to ecosystem health and the survival of the fishing industry. If temperatures rise by 2 degrees C, the study found, coral may stop growing altogether, and may start to dissolve at 3 degrees C. Similarily, acidic ocean waters can hamper shellfish larvae’s ability to grow shells. Acidification is already hurting the shellfish industry — in the U.S., northwestern and East Coast shellfish industries have struggled to adapt to increasingly acidic waters. And pteropods, tiny sea snails that are a keystone species in the Arctic and are an essential food source for many birds, fish and whales, are also threatened by acidity — they too require strong calcium carbonate shells to survive.


Meanwhile, depletion of oxygen is caused by two things: climate change and nutrient runoff, mostly from agriculture, the report stated. Scientists have predicted ocean oxygen content could experience a decline of between 1 and 7 percent by 2100.


tags: historical global warming, historical climate change,

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