Some (Phytoplankton) Like it Acidic

It's generally accepted that increasingly acidified oceans could prove disastrous for most forms of marine life. We say most - coral reefs, certain phytoplankton species and larger organisms - because oceanographers are still hard at work studying the effects of higher carbon dioxide levels on individual species. Many, in fact, have now concluded that higher levels of dissolved carbon dioxide could help some species thrive over others. ScienceNOW's Phil Berardelli reports on a new study by an international group of researchers that has found that Emiliana huxleyi, otherwise known as the common coccolithophore, seems to be handling the pH drop better than most.

Because a higher acidity inhibits the formation of calcium carbonate shells - which coccolithophores have - it was once thought that these miniature phytoplankton would suffer disproportionately from a rise in carbon dioxide levels. Quite the contrary: To their surprise, the scientists found that the coccolithophores couldn't get enough of the stuff - boosting their growth and rate of reproduction to keep up with the higher concentrations.

The question that remains - and is likely to prove much more difficult to answer - is whether these coccolithophores could act as carbon sinks. Though they consume carbon dioxide during photosynthesis, they also release some during the shell formation process - whether these two processes counterbalance remains to be seen (though most scientists doubt any upside would be negligible).

One of my faculty at the University of Southern California, Dave Hutchins, got similar results with several other phytoplankton species. In his case, he subjected several populations to higher levels of carbon dioxide and higher temperatures to gauge the full impact of climate change. The problem was that those species that often benefited most were HABs (or harmful algal bloom species) - not exactly the type of plankton you'd like to have forming large blooms.

Via ::ScienceNOW: Surviving the Ocean Acid Test (news website)

See also: ::A Novel Strategy to Counter Ocean Acidification, ::Al Gore Warns of Crises Facing World's Oceans

Tags: Carbon Dioxide

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