'Rising CO2 levels threaten aquatic food webs'



`Rising CO2 levels threaten aquatic food webs` Sydney: Rising levels of atmospheric carbon dioxide (CO2) are seriously threatening marine plankton, vital for survival of aquatic food webs, whose disappearance could have far-reaching impact, a research says.

The research revealed that around half the CO2 released through human activity dissolves in the ocean, where it forms carbonic acid leading to a decrease in seawater pH. A pH less than seven is said to be acidic and solutions with a pH greater than seven are basic or alkaline.

Scientists found the changes in the pH levels, along with global warming, could lead to poor growth if not death of marine plankton, the journal Nature Climate Change reports.

John Beardall, professor from the School of Biological Sciences, Monash University, who led the study, said the impact that ocean acidification-induced changes have on plankton was a major concern, according to a Monash statement.

"This research suggests the impact of oceanic acidification upon marine plankton could be more serious than previously thought. Acidity levels will more than double by the end of the century as a result of the increase in CO2 levels in the ocean," added Beardall.

Using math modelling and their understanding of cellular physiology, the team has found that many marine plankton will experience a substantially more acidic environment than currently suggested.

Beardall, who worked with Swansea University, the Marine Biological Association, Plymouth, University of Dundee and University of Technology, Sydney, plans to develop the research further to understand the effects of ocean acidification and other aspects of climate change on key phytoplankton species.

IANS