"Acid oceans 'need urgent action'"

From the BBC:

The world's marine ecosystems risk being severely damaged by ocean acidification unless there are dramatic cuts in CO2 emissions, warn scientists.

More than 150 top marine researchers have voiced their concerns through the "Monaco Declaration", which warns that changes in acidity are accelerating.

The declaration, supported by Prince Albert II of Monaco, builds on findings from an earlier international summit.
It says pH levels are changing 100 times faster than natural variability.

Based on the research priorities identified at The Ocean in a High CO2 World symposium, held in October 2008, the declaration states:
"We scientists who met in Monaco to review what is known about ocean acidification declare that we are deeply concerned by recent, rapid changes in ocean chemistry and their potential, within decades, to severely affect marine organisms, food webs, biodiversity and fisheries."


•The oceans are thought to have absorbed about half of the extra CO2 put into the atmosphere in the industrial age
•This has lowered its pH by 0.1
•pH is the measure of acidity and alkalinity
•The vast majority of liquids lie between pH 0 (very acidic) and pH 14 (very alkaline); 7 is neutral
•Seawater is mildly alkaline with a "natural" pH of about 8.2
•The IPCC forecasts that ocean pH will fall by "between 0.14 and 0.35 units over the 21st Century, adding to the present decrease of 0.1 units since pre-industrial times"

Natural lab shows sea's acid path (previous article):

...Globally, the seas now have an average pH of about 8.1 - down about 0.1 since the dawn of the industrial age.

Around the vents, it fell as low as 7.4 in some places. But even at 7.8 to 7.9, the number of species present was 30% down compared with neighbouring areas.

Coral was absent, and species of algae that use calcium carbonate were displaced in favour of species that do not use it.

Snails were seen with their shells dissolving. There were no snails at all in zones with a pH of 7.4.

Meanwhile, seagrasses thrived, perhaps because they benefit from the extra carbon in the water.

...Last month (May08), scientists reported that water with CO2 levels high enough to be "corrosive" to marine life was rising up off the western US coast.

Bottom water naturally contains more CO2 than at shallower depths. This scientific team argues that human emissions have pushed these levels even higher, contributing to pH values as low 7.5 in waters heavily used by US fishermen.

"If [pH 7.8] is a universal 'tipping point', then it indicates that sections of the western coast waters off North America may have passed this threshold during periods when this upwelling of waters high in CO2 occurs," commented Carol Turley from Plymouth Marine Laboratory