Researchers at the National Center for Atmospheric Research (NCAR) warn that oceans around the world are bound to lose much of their oxygen concentrations by the year 2030 as a result of global warming.

In a study featured in the journal Global Biogeochemical Cycles, Matthew Long and his colleagues at the NCAR examined how climate change impacts the amount of oxygen typically found in the Earth's oceans.

While they discovered that oxygen levels in these bodies of water are diminishing, they are unsure just how much of this phenomenon is actually caused by the warming of the planet. However, they were able to determine a timeframe of when the effects of climate change could very well overwhelm the natural ability of oceans to handle such deoxygenation.

Based on the team's computer simulations, global warming could cause oceans to lose so much oxygen within the next couple decades that it could end up significantly limiting the ability of marine organisms to breathe.

Ocean Deoxygenation

Marine scientists have been studying the effects of the deoxygenation of oceans for years, though the issue has not gotten much widespread attention.

The phenomenon has become problematic that large areas of the world's oceans are now more hostile to marine life than ever before. This can be seen in deep-sea fish, such as marlin and sailfish, preferring to stay near the surface of the ocean despite being known to traditionally hunt for prey at great depths.

"Two hundred meters down, there is a freight train of low-oxygen water barreling toward the surface," marine biologist William Gilly from Stanford University pointed out. However, this problem has not received enough attention as it should.

The portions of the ocean that Gilly was referring to are very much different from coastal dead zones such as those found in the Gulf of Mexico. Rather they are large swaths of deep oceans that can stretch to thousands of miles off the coast.

These areas are known for their naturally low oxygen levels and are continuing to spread vertically and horizontally across the world's oceans. Some of those affected by these low-oxygen regions include portions of the Atlantic and eastern Pacific and a majority of the Bay of Bengal.

Studies have shown that over the past five decades, low-oxygen areas have reached more than 1.7 million square miles of the world's oceans.

Researchers are concerned that this phenomenon could alter the Earth's seas as much as ocean acidification or global warming could. It could significantly change where and what marine organisms eat and even affect which of these creatures live or die.

Ocean deoxygenation is already changing traditional ocean food chains and now threatens to exacerbate existing problems concerning the oceans of the world.

Many scientists are still debating just how much of the lost oxygen is caused by natural cycles and how much of it is caused by global warming. However, they do agree that the ongoing changing of the Earth's climate will only lead to even more oxygen losses as well as an acceleration of the rate of loss.

Photo: Ed Bierman | Flickr