(AP)—Oceans’ rising acid levels have emerged as one of the biggest
threats to coral reefs, acting as the “osteoporosis of the sea” and
threatening everything from food security to tourism to livelihoods, the
head of a U.S. scientific agency said Monday.
speed by which the oceans’ acid levels has risen caught scientists
off-guard, with the problem now considered to be climate change’s
“equally evil twin,” National Oceanic and Atmospheric Administration
chief Jane Lubchenco told The Associated Press.
got sort of the perfect storm of stressors from multiple places really
hammering reefs around the world,” said Lubchenco, who was in Australia
to speak at the International Coral Reef Symposium in the northeast city
of Cairns, near the Great Barrier Reef. “It’s a very serious
absorb excess carbon dioxide in the atmosphere, increasing sea acidity.
Scientists are worried about how that increase will affect sea life,
particularly reefs, as higher acid levels make it tough for coral
skeletons to form. Lubchenco likened ocean acidification to
osteoporosis—a bone-thinning disease—because researchers are concerned
it will lead to the deterioration of reefs.
initially assumed that the carbon dioxide absorbed by the water would
be sufficiently diluted as the oceans mixed shallow and deeper waters.
But most of the carbon dioxide and the subsequent chemical changes are
being concentrated in surface waters, Lubchenco said.
those surface waters are changing much more rapidly than initial
calculations have suggested,” she said. “It’s yet another reason to be
very seriously concerned about the amount of carbon dioxide that is in
the atmosphere now and the additional amount we continue to put out.”
acidity levels are especially problematic for creatures such as
oysters, because acid slows the growth of their shells. Experiments have
shown other animals, such as clown fish, also suffer. In a study that
mimicked the level of acidity scientists expect by the end of the
century, clown fish began swimming toward predators, instead of away
from them, because their sense of smell had been dulled.
just beginning to uncover many of the ways in which the changing
chemistry of oceans affects lots of behaviors,” Lubchenco said. “So
salmon not being able to find their natal streams because their sense of
smell was impaired, that’s a very real possibility.”
potential impact of all of this is huge, Lubchenco said. Coral reefs
attract critical tourism dollars and protect fragile coastlines from
threats such as tsunamis. Seafood is the primary source of protein for
many people around the world. Already, some oyster farmers have blamed
higher acidity levels for a decrease in stocks.
attempts to address the problem are already under way. Instruments that
measure changing acid levels in the water have been installed in some
areas to warn oyster growers when to stop the flow of ocean water to
But that is only a short-term solution, Lubchenco said. The most critical element, she said, is reducing carbon emissions.
carbon dioxide that we have put in the atmosphere will continue to be
absorbed by oceans for decades,” she said. “It is going to be a long
time before we can stabilize and turn around the direction of change
simply because it’s a big atmosphere and it’s a big ocean.”
Source: The Associated Press