Smothered oceans: Extreme oxygen loss in oceans accompanied past global climate change

Smothered oceans
This map of the California Current shows the extent of the low-oxygen seafloor. Yellow indicates intermediate hypoxia, while red zones are areas of severe oxygen loss. Credit: UC Davis

Seafloor sediment cores reveal abrupt, extensive loss of oxygen in the ocean when ice sheets melted roughly 10,000-17,000 years ago,according to a study from the University of California, Davis. Thefindings provide insight into similar changes observed in the ocean today.

In the study, published in the journal PLOS ONE, researchers analyzed marine sediment cores from different world regions to document the extent to which low oxygen zones in the ocean have expanded in the past, due to .

From the subarctic Pacific to the Chilean margins, they foundevidence of extreme oxygen loss stretching from the upper ocean to about 3,000 meters deep. In some oceanic regions, such loss took place over a time period of 100 years or less.

"This is a global story that knits these regions together and showsthat when you warm the planet rapidly, whole can lose oxygen very abruptly and very extensively," said lead author Sarah Moffitt, a postdoctoral scholar with the UC Davis Bodega Marine Laboratory and formerly a Ph.D. student with the Graduate Group in Ecology.

Marine organisms, from salmon and sardines to crab and oysters,depend on oxygen to exist. Adapting to an ocean environment withrapidly dropping would require a major reorganization of living things and their habitats, much as today polar species on land are retreating to higher, cooler latitudes.

The researchers chose the deglaciation period because it was a time of rising global temperatures, and sea levels—many of the signs the Earth isexperiencing now.

"Our modern is moving into a state that has no precedent inhuman history," Moffitt said. "The potential for our oceans to lookvery, very different in 100-150 years is real. How do you use thebest available science to care for these critical resources in thefuture? Resource managers and conservationists can use science like this to guide a thoughtful, precautionary approach to environmental management."


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Journal information: PLoS ONE

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Jan 28, 2015
Looks like somebody's spacebar isn't working as well as it used to. ;-)

But seriously, eat sushi while you can!

Jan 28, 2015
"when you warm the planet rapidly, whole ocean basins can lose oxygen"
This is nonsense. There is NO evidence provided WARMING caused the loss.
Even today, correlation of co2 vs temperature exist BUT it is NOT just one way. Lots co2 are released from ice due to warming. Other than that 150m(500feet) raise in seawater level will kill lots of plants by shore plus land submerged.

There is man made components in global warming, but bottom line is there is ALWAYS warming after glacial maximum. There's long term sun cycle, 11 year cycle, CO2, and comet. So expect dry/drought in summer and longer harsher winter and extreme weather. Extreme weather is not going change too much unless CO2 level are drastically reduced, which cannot happen without nuclear fusion power plants or population reduction.

Jan 28, 2015
There is man made components in global warming, but bottom line is there is ALWAYS warming after glacial maximum.

Keep in mind that the earth peaked in warming after the last glacial maximum about 4000 - 8000 years ago. Then the earth started to cool again until recently when CO2 levels overcame that cooling effect and that recent warming is due pretty much entirely to humans (http://www.realcl...cott.png ).

Jan 29, 2015
Couldn't some of that be caused by massive influxes of fresh water from both of the pole regions and cause the local natural circulation systems and even possibly regional areas to break down and the water temporarily stratify due to it? That would cause the oxygen level to drop off until the water mixed enough to get the normal circulation patterns for an area operating again.

Jan 29, 2015
There is man made components in global warming, but bottom line is there is ALWAYS warming after glacial maximum.

Keep in mind that the earth peaked in warming after the last glacial maximum about 4000 - 8000 years ago. Then the earth started to cool again until recently when CO2 levels overcame that cooling effect and that recent warming is due pretty much entirely to humans (http://www.realcl...cott.png ).


Or it goes up and down all the time and doesn't have particularly distinguishable trends on 100year scales which let you predict 1000year scales (actual climate is +1000year stuff)

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