Corrosive Oceans: Carbon Emissions Threaten Ecosystem

Aug. 22, 2008— -- Under the vast, trackless surface of the ocean, scientists have discovered a monster of a problem, literally rising from the deep.

The world's oceans are becoming more acidic and corrosive because of the same carbon emissions that cause another immense problem: global warming.

"We think this can have devastating impacts on our ocean ecosystem," said Richard Feely, program manager at the National Oceanic and Atmospheric Association's Pacific Marine Environmental Laboratory.

Cold water naturally absorbs carbon dioxide from the air, and the oceans have absorbed about half of the carbon emissions we've spewed out in the last two centuries -- hundreds of billions of tons of it.

Scientists first thought that was a good thing, since all that carbon sinking into the ocean meant it wouldn't be causing even more global warming in the air.

But Feely says that "the ocean ecosystem can no longer handle all this excess Co2."

The problem? Excess carbon dioxide turns seawater into carbonic acid. Scientists report the ocean's new acidity worldwide is crippling sea creatures in their efforts to form their shells and skeletons, to breathe, to move and catch prey, and to reproduce and mature.

Scientists have been slow to identify the problem, partly because it's invisible. Life in the ocean is mostly out of sight and out of mind, down there under that vast gray surface. Also invisible is all the carbon dioxide and its absorption into the ocean surface. But now scientists are beginning to see it all.

Huge amounts of fossil fuels have been burned since the industrial age began, and those carbon emissions have already increased the ocean's acidification by 30 percent. This summer scientists were stunned to find acidic waters -- normally trapped in the deeper parts of the ocean -- rising up to shallow waters just off shore on the continental shelf, where so much sea life is found.

"This corrosive ocean acidified water has come on to our continental shelf years 50 to 100 years before we ever thought it would be occurring," Feely said.

A fifth of the world's population depends on seafood for its protein, and the acidification is affecting shrimp, lobster and scallops, and the tiny creatures that are at the base of the food chain for salmon, mackerel and other fish.

Also under attack are coral reefs that protect shorelines and support much sea life. Scientists are seeing this phenomenon off America's West Coast, and if it's happening there, it's most likely happening worldwide. The global ocean is a single swirling mass, and marine biologists are finding the devastating effects of ocean acidification everywhere.

If the acid levels continue to rise, there'll be more and more creatures you can no longer find in the wild. You'll have to go to places like the Shedd Aquarium in Chicago to see certain aquatic species.

Far from any ocean, the aquarium has to make its own sea water to keep its dolphins, whales and coral reefs happy and alive, adding chemicals until the pH meter reads an optimal acidity of 8.2.

"Saltwater fish are delicate, and they need a stable environment," said Mark Schick, collection manager at the Shedd Aquarium. "Now, with acidification that's going to make it harder for animals to deposit a skeleton… they can't put that shell down, they can't grow, they're going to go extinct."

Scientists say all this will get worse. The acidic water welling up off California this year was from carbon emissions 50 years ago. Carbon emissions today are much greater, so there are grave concerns about seawater acidification 50 years from now. … And beyond.

"It will change 150 percent by the end of this century," said Feely.

Discovery of this ocean acidification problem is so recent, no one has suggested any practical way even to slow it down yet -- except the obvious one, the same as for that other problem of global warming: drastically cut human induced carbon emissions worldwide and immediately.