Ocean acidification
The burning of fossil fuel carbon leads to an incease in atmospheric CO2, some of which enters the ocean and causes a demonstrable reduction in seawater pH, ocean acidification. The effects of this will be complex and hard to disentangel from changes caused by other pressures on the marine environment. However a mounting body of literature suggests that they may be serious, particularly for organisms which make their shells from calcium carbonate.
Around 30% of the carbon dioxide generated by human activity has been absorbed in the ocean. This increase in dissolved carbon dioxide is leading to changes in the basic chemistry of seawater, including decreasing the pH which makes the ocean more acidic - a process that has been termed ocean acidification. The consequences of ocean acidification for marine organisms, food webs and the oceanic cycling of essential nutrients and elements is currently a major topic of oceanographic research.
Ocean acidification may be detrimental to many marine species, especially those forming calcium carbonate body parts - although recent research has shown that some marine organisms have a high capacity to cope with changes in seawater chemistry. For other species, increased availability of carbon dioxide can have a positive effect, allowing them to grow faster. However, more than carbon dioxide is needed for growth and so other factors may become limiting, such as nutrients. Clearly, understanding the overall effect that ocean acidification has on marine species and ocean processes requires a better understanding of a complex puzzle - how does the physiology and ecology of a marine organism interact with its environment?
Research into the effects of ocean acidification includes both laboratory and field-based experiments, as well as spatial and time series observations along repeat transects or strong gradients in seawater chemistry. Combining these different approaches into a consensus on the effects of ocean acidification and other environmental factors on the biology and chemistry of the oceans is a major goal of the Ocean Biogeochemistry and Ecosystems (OBE) Research Group at NOC.
Links to ocean acidification articles, websites and blogs involving OBE research
Poulton, A.J. (2011) Ocean Acidification and Plankton: Litmus-testing the base of the marine food-chain. Ocean Challenge vol. 18, 44 - 48.
Charalampopoulou et al. (2011) Irradiance and pH affect coccolithophore community composition on a transect between the North Sea and the Arctic Ocean. Marine Ecology Progress Series 431: 25-43.
UK Ocean Acidification Research Programme (UKOARP) - http://www.oceanacidification.org.uk/
June 2011 - Round the UK, RRS Discovery cruise - http://noc.ac.uk/news/rrs-discovery-cruise-366
January 2011 - Great Belt Research Cruise, RV Melville - http://greatbeltresearchcruise.com/
