silver lining of ocean acidification

While the April 21st post on this blog made it seem as if enriching the world's oceans with CO2 was all doom and gloom for inhabitants of the marine world, it seems as if one member of kingdom Protista is actually rather enjoying the change. Coccolithophores are single-celled calcareous algae, also known as golden algae. They have inhabited the earth's oceans, predominantly occupying the mid to low latitudes, for roughly 220 million years. (Thanks to Tom Marchitto for this info)

These critters rely on the formation of coccoliths (round plates made of calcite, hence the adjective calcareous) to protect themselves, which has led scientists to predict that with the warming and related acidification of the earth's oceans, cocolithophores would suffer reduced populations. According to a recent article by Kenneth Chang of the NY Times, however, the reduction in the ocean's pH from 8.2 in pre-industrial times to 8.1 today, has resulted in a 40% increase in the average mass of coccolithophores in the oceans!

An article in the April 18th issue of Science, written by Dr. Iglesias-Rodriguez and her graduate student, Paul Halloran, may explain this observation. While prior lab studies of the effects of pH on coccolithophores had added acid to water in which the algae lived, the new study instead added dissolved CO2 to the water. The result was that the photosynthetic capabilities of the algae were substantially increased, resulting in individuals growing to larger sizes.

While, on the whole, ocean acidification is likely to prove a net detriment to marine ecosystems, it seems as if there are a few creatures who may actually benefit (at least in the short-term) from incremental decreases in the pH of the world's oceans as a result of greenhouse gases!