Saturday, May 10, 2014
Climate change's evil twin, ocean acidification: chickens come home to roost.
The largely untold story of CO2 and climate change is, of course,
ocean acidification: It’s here, now an starting to kill off marine life.
The oceans cover most of the Earth’s surface, and the oceans
have taken up vast amounts of the carbon-dioxide pumped into the atmosphere by
fossil fuel burning, deforestation and other activities.
Those chickens are coming home to roost.
(Image: Ocean acidification is eroding the shells of a key
tiny sea creature, the pteropod. The name means wing-foot, and refers to its
split foot, which it uses like tiny flippers for movement. Credit NOAA.)
Mix CO2 with water and you get carbonic acid. It happens in a Coke bottle. And it happens in the laboratory. And sure
enough, it happens in the ocean. The oceans have become more acid. And what does that matter?
Have you ever thrown a piece of seashell (alkaline) into a
dish of vinegar (acid)? Try it. The shell sizzles and pops and eventually disappears.
The loss of shell-forming marine life was an early
prediction about climate change. Now, it’s happening.
A study released May 1 shows that the shells of a small sea
snail are dissolving.
“We found 53% of onshore individuals and 24% of offshore
individuals on average to have severe dissolution damage,” wrote the authors of
this paper, referring to pteropods—a group of free-swimming deep-ocean sea snails.
Here’s an easier-reading NOAA report on the same study.
Hawai`i has actually benefitted in one small way from
acidification. Due to higher-acidity in upwellings off the West Coast, an
oyster farming company moved its oyster hatchery to Hawaii. This story in theSeattle Times said: “Carbon dioxide from fossil-fuel emissions had turned
seawater in Willapa Bay along Washington’s coast so lethal that slippery young
Pacific oysters stopped growing.”
They can still grow the adult oysters in Washington waters,
but the animals have trouble reproducing there.
In the Islands, there is concern that our coral reefs are at
risk. Corals, after all, are made of calcium carbonate, an alkaline material
that also makes up oyster and pteropod shells.
The National Climate Assessment’s Pacific section includes
these words:
“The amount of calcium carbonate, the biologically important
mineral critical to reef-building coral and to calcifying algae, will decrease
as a result of ocean acidification. By 2035 to 2060, levels of one form of the
mineral (aragonite) are projected to decline enough to reduce coral growth and
survival around the Pacific, with continuing declines thereafter.”
Not to be too hysterical about this, if Hawai`i’s coral
reefs begin dissolving, the potential impacts are severe: lost habitat for reef
fish, lost snorkeling opportunity, disappeared surf breaks, lost coastal
protection from wave action...you can think of others.
© Jan TenBruggencate 2014
Posted by Jan T at 8:34 AM
Labels: Climate Change, Conservation, Fisheries, Government, Marine Issues, Oceanography, Pollution, Reefs, Sharks, Weather, Zoology
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