Global warming harming marine life: Studies
TEHRAN, January 5 - Global warming
is making the world's oceans sicker, depleting them of oxygen and harming
delicate coral reefs more often, two studies show.
TEHRAN, Young Journalists Club (YJC) -Global warming is making the world's oceans
sicker, depleting them of oxygen and harming delicate coral reefs more often,
two studies show.
The
lower oxygen levels are making marine life far more vulnerable, the researchers
said. Oxygen is crucial for nearly all life in the oceans, except for a few
microbes.
"If
you can't breathe, nothing else matters. That pretty much describes it,"
said study lead author Denise Breitburg, a marine ecologist at the Smithsonian
Environmental Research Center. "As seas are losing oxygen, those areas are
no longer habitable by many organisms."
She
was on a team of scientists, convened by the United Nations, who reported that
the drop in oxygen levels is getting worse, choking large areas, and is more of
a complex problem than previously thought.
A
second study finds that severe bleaching caused by warmer waters is hitting
once-colorful coral reefs four times more often than they used to a few decades
ago. Both studies are in Thursday's edition of the journal.
When
put all together, there are more than 12 million square miles (32 million
square kilometers) of ocean with low oxygen levels at a depth of several
hundred feet (200 meters), according to the scientists with the Global Ocean
Oxygen Network. That amounts to an area bigger than the continents of Africa or
North America, an increase of about 16 percent since 1950.
Their
report is the most comprehensive look at oxygen deprivation in the world's
seas.
"The
low oxygen problem is the biggest unknown climate change consequence out
there," said Lisa Levin, a study co-author and professor of biological
oceanography at the Scripps Institution of Oceanography.
Levin
said researchers have seen coastal "dead zones" from fertilizer
pollution from farms before, as well as areas of low oxygen in open ocean
blamed on warmer waters, but this study shows how the two problems are
interconnected with common causes and potential solutions.
"Just
off S
outhern
California, we've lost 20 to 30 percent of our oxygen off the outer
shelf," Levin said. "That's a huge loss."
Some
low oxygen levels in the world's ocean are natural, but not this much,
Breitburg said. A combination of changes in winds and currents — likely from
climate change — is leaving oxygen on the surface, and not bringing it down
lower as usual. On top of that, warmer water simply doesn't hold as much oxygen
and less oxygen dissolves and gets into the water, she said.
"Oxygen
loss is a real and significant problem in the oceans," said University of
Georgia marine scientist Samantha Joye, who wasn't part of the study but
praised it. Levels of ocean oxygen are "changing potentially faster than
higher organisms can cope."
Source:
Press TV
author: D-Ezatiyan - Date: 1/6/2018