David Gray/REUTERS/File
Peter Gash, owner and manager of the Lady Elliot Island Eco Resort in the Great Barrier Reef area, snorkels during an inspection of the reef's condition in an area called the 'Coral Gardens' located at Lady Elliot Island, Australia, in 2015.

Decreasing ocean oxygen levels could be catastrophic, scientists say

A new study by researchers at the National Center for Atmospheric Research finds that ocean oxygen levels are decreasing due to climate change, and that the effects will only get worse as the ocean warms. 

Whales and swimming humans must surface in order to breathe, but most marine life depends on dissolved oxygen – and now, climate change is decreasing oxygen levels in Earth's oceans.

According to a new study in Global Biogeochemical Cycles, fish, clams, shrimp, octopuses, and more may soon be gasping for air.

"Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life," lead author Dr. Matthew Long, a researcher at the National Center for Atmospheric Research says in a press release from the Center (NCAR). 

How does a warming climate affect the ocean's oxygen levels?

The entire ocean gets oxygen from the water surface, where oxygen is absorbed from the atmosphere, or from phytoplankton that release oxygen into the water through photosynthesis.

When the planet warms, as it is happening now, less oxygen enters the top layers of the ocean. Even less oxygen filters down to the deeper, colder, reaches of the sea: warm water is more buoyant than cold water, so the warm surface waters are unlikely to reach the ocean's depths.

This means that a warming earth has grave consequences for sea life that relies on oxygen, including such familiar creatures as crabs, squids, and many kinds of fish. 

"Many forms of marine life depend on oxygen, they require oxygen to survive," Dr. Long tells The Christian Science Monitor in a phone interview. "As oxygen levels decline, the increasing stresses on ocean systems, as well as implications for our ability to extract the services of these marine resources."

Why are scientists just discussing this problem now?

Researchers have known for years that decreasing oxygen levels in the ocean would impact marine life. But the unique contribution of this study, according to Long, is its use of an atmospheric supercomputer to provide earth system simulations that can tell scientists about the future of the oceans.

For a long time, he says, scientists had a difficult time separating natural variations in oxygen concentration at the ocean's surface from the effects of climate change.

"What we've done is apply a novel technique to separate the components of variability," he explains.

Using NCAR's supercomputer, this study found the point at which natural variations in ocean oxygen levels are overwhelmed by climate change stimulated changes – and it's less than 15 years away. Deoxygenation is already happening, but its spread will likely increase over the next twenty years. 

"The bottom line," he adds, "is that without addressing climate warming, there is not much we can do to address deoxygenation."

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Decreasing ocean oxygen levels could be catastrophic, scientists say
Read this article in
QR Code to Subscription page
Start your subscription today