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Acidic Oceans Could Spell Doom For Many Sea Creatures

Posted on: Wednesday, 11 March 2009, 13:25 CDT

A top ocean scientist warned that carbon dioxide emissions from human activities are acidifying the oceans and threatening some sea life with mass extinction, BBC New reported.

It is impossible to know how marine life will cope, but it is feared that many species will not survive, according to Dr. Carol Turley from Plymouth Marine Laboratory.

Researchers say CO2 emissions have already turned the sea about 30 percent more acidic since the Industrial Revolution and it is more acidic now than it has been for at least 500,000 years, they added.

As greenhouse gas emissions increase through the 21st Century, the problem is set to worsen.

Turely, who is chairing a session on ocean acidification at the Copenhagen Climate Change Congress, told BBC News she was “very worried” for ocean ecosystems that are currently productive and diverse, suggesting we may be heading for a mass extinction, as the rate of change in the oceans hasn't been seen since the dinosaurs.

"It may have a major impact on food security. It really is imperative that we cut emissions of CO2," she added.

Many sea life experts say the problem is most acute for creatures that make calcified shells, as laboratory tests suggest starfish may be wiped out before the end of the century if current emissions trends continue.

Mussels may not be able to cope, either. Oysters may be less vulnerable, and farmed oysters may fare better than wild oysters.

Turley said the one thing that is certain is that things will change. "We just don't know yet exactly how they will change. It is not a very wise experiment to be making," she said.

However, climate change and overfishing may ruin the seas before acidification, according to Professor Andy Watson, an ocean biologist from the University of East Anglia.

While he condemns increases in CO2 from human activities, he pointed out that ocean acidity also fluctuates naturally and wonders if some creatures might adapt to the changes over time.

"(In) many of the experiments that are being done at the moment, sudden changes are made; the CO2 is quickly raised, for example, or the acidity is quickly raised. Of course, that's not really what will happen in the real world," he told BBC News.

He said there would instead be a gradual ramping up of CO2 and acidity and scientists don't know whether organisms will be able to adapt or how quickly they'll be able to adapt.

However, Professor Tony Knapp, who runs the BIOS institute in Bermuda, defends his conclusion that the recent increase in acidity has been caused by CO2 emissions from burning fossil fuels.

"It took me a long time to determine that I was convinced... I'm a cynic at heart. But if you look at the data, and you're intimate with the data, there's really no other conclusion you could make".

Scientists believe that on the island of Ischia, in the Bay of Naples, Italy, they have evidence that many creatures will fail to adapt to increased acidification.

Part of the island contains seawater that has been more acidic for thousands of years from volcanic CO2 vents released into the seabed.

He suggests the prospects for shell-forming organisms are bleak if research here presents an accurate picture of future oceans, although some of the creatures that appear to survive increased levels of acidity in short-term laboratory studies are not present here in the real world at the same levels of pH.

Dr. Jason Hall-Spencer from Plymouth University, who researched the site with help from the Naples-based Benthic Ecology Laboratory at Stazione Zoologica, said they are worried that the changes have clearly made life impossible for shell-forming creatures.

"When you start messing around with a complex ecosystem it is impossible to tell what will happen," he added.

He claims the Ischia site does not present a perfect experiment for future oceans because levels of acidity shift regularly as the currents change, whereas future oceanic pH levels will be more stable.

Ocean acidification is becoming known as "the other CO2 problem" and is now considered a new branch of science and researchers were initially uncertain how seriously to take the threat.

Turley said in 2004 she did a Google search for ocean acidification and only got 17 hits, but she now gets hundreds of thousands of returns.

“There is much more evidence to show this will be a problem for the future - indeed it may even be a problem for now,” she said.

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On the Net:

• Plymouth Marine Laboratory
• Copenhagen Climate Change Congress
• University of East Anglia
• Plymouth University

Source: redOrbit Staff & Wire Reports

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