Greenhouse gases imperil oceans'

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McClatchy Washington Bureau | 11/11/2008 | Report: Greenhouse gases
imperil oceans' web of lifeHome

Posted on Tuesday, November 11, 2008 Report: Greenhouse gases
imperil oceans' web of life



By Renee Schoof | McClatchy Newspapers
WASHINGTON — Corals, lobsters, clams and many other ocean creatures —
including
some at the bottom of the food chain — may be unable to withstand the
increasing
acidity of the oceans brought on by growing global-warming pollution,
according
to a report Tuesday from the advocacy group Oceana.
Based on scientific findings of the past several years, Oceana's
report "Acid
Test" examines the far-reaching consequences of the accumulation of
heat-trapping gases, particularly carbon dioxide, in the world's
oceans.
A high level of carbon dioxide in seawater depletes the carbonate that
marine
animals need for their shells and skeletons. Creatures who are at risk
if trends
continue include corals, which provide habitats for about a quarter of
the
world's fish; things many people like to eat, including shrimp and
lobster; and
pteropods, or swimming sea snails, which are an important part of the
base of
polar and sub-polar food chains.
Oceana, an international organization that calls for reducing
pollution in order
to save marine life, called for sharp reductions in carbon dioxide
emissions
worldwide through increased energy efficiency, a shift away from
fossil fuels
and the protection of forests, which absorb carbon dioxide.
"We set the goal at saving the corals," said Jacqueline Savitz, one of
the
authors of the report. The goal is in line with the emissions
reductions that
the Intergovernmental Panel on Climate Change reported last year would
be
necessary: an 85 percent reduction globally from 2000 levels by 2050.
Oceana's report said that would require a 25 percent to 40 percent
reduction by
industrialized countries by 2020.
The acidity of the oceans' surfaces has increased 30 percent since
before the
Industrial Revolution, and the current trend would increase it 100
percent by
the end of this century, exceeding levels of the past 20 million
years, the
report says.
"Scientists are realizing that climate change and acidification are
progressing
much faster than science originally predicted," said another of the
Oceana
report's authors, Ellycia Harrould-Kolieb.
Acidification adds to other problems for corals: warmer water causing
bleaching,
overfishing, pollution and the use of dynamite to capture fish in
Asia.
Here are some of the findings about ocean acidification in the report:
The increased amount of carbon dioxide absorbed by the oceans
changes the
movement of nutrients and chemicals and also affects the growth,
reproduction
and disease resistance of many species.
Impacts on corals and pteropods could have ripple effects through
ecosystems,
ultimately harming large ocean animals and commercial fisheries.
Cooler water holds higher levels of carbon dioxide and becomes more
acidic.
The current trend of carbon dioxide emissions would leave cold-water
corals
severely stressed by 2040, and two-thirds of them would be in a
corrosive
environment by the end of the century.