World's oceans in peril

"From a climate change/fisheries/pollution/habitat destruction point of view, our nightmare is here, it's the world we live in."

This bleak statement about the current status of the world's oceans comes from Dr Wallace J Nichols, a Research Associate at the California Academy of Sciences. Al Jazeera asked Dr Nichols, along with several other ocean experts, how they see the effects climate change, pollution and seafood harvesting are having on the oceans.

Their prognosis is not good.

Dr Nancy Knowlton is a marine biologist at the Smithsonian Museum of Natural History in Washington DC. Her research has focused on the impact of climate change on coral reefs around the world, specifically how increasing warming and acidification from carbon dioxide (CO2) emissions have affected oceans.

While she is unable to say if oceans have crossed a tipping point, Dr Knowlton offered this discouraging assessment, "We know it's bad and we know it's getting worse, and if we care about having coral reefs, there's no question we have to do something about CO2 emissions or we won't have coral reefs, as we do now, sometime between 2050-2100."

Since at least one quarter of all species of life in the oceans are associated with coral reefs, losing them could prove catastrophic.

"Coral reefs are like giant apartment complexes for all these species, and there is intimacy," Dr Knowlton explained. "If that starts breaking down, these organisms, which include millions of species around the world, lose their homes. Even if they aren't eating coral, they depend on it."

CO2 is the main greenhouse gas resulting from human activities in terms of its warming potential and longevity in the atmosphere, and scientists continually monitor its concentration.

In March 1958, when high-precision monitoring began, atmospheric CO2 was 315.71 parts per million (ppm). Today, atmospheric CO2 is approaching 390 ppm.

350 ppm is the level many scientists, climate experts, and progressive national governments say is the safe upper limit for CO2 in the atmosphere.

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By 2009, the Pacific oyster industry was reporting 80 per cent mortality for oyster larvae due to the corrosive nature of the water.

"Acidification has the potential to change food security around the world, so I think it's incumbent upon the entire world to recognise this and deal with it," Cooley told Al Jazeera.

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