Ocean acidification

Ocean acidification doesn’t necessarily mean less calcification, or at least for coccolithophorids, according to a new study by Iglesias-Rodriguez et al. (Science, 17 April 2008).

As atmospheric concentrations of carbon dioxide rise due to human activities, the oceans will continue to become more acidic as they absorb the extra gas, but the effects on calcifying phytoplankton may not be simple to predict. In fact, over the industrial age, while CO2 emissions are steadily rising, coccolithophorids seemed to have increased their calcification.
Continue reading ‘Effect of Ocean Acidification ‘turned on its head’’

Climate change is a core issue on the Rudd Government’s agenda. But there’s another carbon problem that has been avoided and is largely independent of global warming.

In a speech to the Australian Strategic Policy Institute last week on Australia’s focus on the Pacific, parliamentary secretary for Pacific Island affairs Duncan Kerr pointed to the effect of marine acidity on coral reefs, the backbone of economic activity for many islander communities. Kerr noted that if land drowns and coral reefs die, the Pacific faces mass movements of people, presenting strategic and humanitarian challenges for Australia.
Continue reading ‘When our oceans turn sour’

Amid concerns about the damage that rising levels of CO2 will do to the oceans, including to corals and other species, there seems to be good news for at least one group of creatures.

Biological oceanographer M. Debora Iglesias-Rodriguez of the National Oceanography Center at the University of Southampton, U.K., found that one species of single-celled phytoplankton, Emiliania huxleyi, increases its calcification rate as CO2 levels rise in the water.
Continue reading ‘Plankton hold surprise for climate research’

Increased carbon dioxide in the Earth’s atmosphere is causing microscopic ocean plants to produce greater amounts of calcium carbonate (chalk) – with potentially wide ranging implications for predicting the cycling of carbon in the oceans and climate modelling.

That is the conclusion of an international team of scientists led by investigators based at the UK’s National Oceanography Centre, Southampton and the University of Oxford, published in the journal, Science, on Friday, 18th April 2008.
Continue reading ‘Increasing levels of atmospheric CO2 cause a rise in ocean plankton calcification’

Scientists have discovered that some plankton can thrive in acidic oceans, which are a result of increased levels of carbon dioxide.

According to a report in New Scientist, this was discovered by Debora Iglesias-Rodriguez from the National Oceanography Centre at the University of Southampton, UK, and her colleagues.
Continue reading ‘Scientists have discovered that some plankton can thrive in acidic oceans’

Most life in the ocean will suffer as carbon dioxide levels increase and the water becomes more acidic. Some plankton will buck the trend, however, thriving and putting on weight as carbon dioxide levels rise – but it remains to be seen how this will affect the global carbon balance.

Débora Iglesias-Rodríguez, from the National Oceanography Centre at the University of Southampton, UK, and her colleagues, simulated the increase in dissolved carbon dioxide in surface ocean waters by bubbling carbon dioxide through cultures of coccolithophores, a type of single-celled photosynthesising plankton.

In previous experiments water acidity had been regulated by simply adding acid or base, but this method has been criticised for being too artificial. Iglesias-Rodríguez’s method found that higher carbon dioxide concentrations increased calcification, speeding up growth of the tiny calcite plates on the plankton cell.

Continue reading ‘Acidic oceans may be water of life for plankton’