Ocean acidification data synthesis for the North Sea

Ocean acidification is an inevitable consequence of increasing carbon dioxide (CO2) in the atmosphere. When CO2 dissolves in seawater, it increases hydrogen ion concentration (H+) and hence reduces pH. It also changes the concentrations of carbonate and bicarbonate ions, increasing the solubility of calcium carbonate. The potential for these chemical changes to have potentially serious biological, ecological and socio-economic consequences was realised 15-20 years ago, and many experimental studies have since been carried out on marine species in the laboratory, using pH (and pCO2) values expected to occur in future, under 'business as usual' climate change scenarios. There have also been "open ocean" measurements made of decadal-scale changes in seawater chemistry, confirming that ocean acidification is a real event.

What has - unfortunately - been lacking until recently is the effort to measure ocean acidification in shelf seas and coastal waters, in the context of the natural spatial and temporal variability of the processes (biological and physical) that also affect pH and carbonate chemistry. This is not straightforward: few laboratories in the UK (indeed in the world) are able to directly measure pH itself with the necessary accuracy and precision to detect longterm changes; instead, pH is usually calculated from other measurements. These other measurements are also potentially problematic; both technical skill and careful quality control are needed.

Whilst the UK Ocean Acidification research programme (UKOA), the Defra-funded PLACID project and other research groups elsewhere in Europe have recently succeeded in making the necessary measurements of natural ocean acidification conditions, no-one has yet tried to bring this information together on a 'regional sea' basis, to show what conditions marine life currently experiences, from sea surface to seafloor, its seasonal changes, and the importance of local factors in determining observed variability. High resolution models can simulate some of these processes, but have yet to be fully tested against 'real data'.

By working at the Centre for Environment, Fisheries and Aquaculture Science (Cefas) and linking with leading ocean acidification researchers and the UKOA Science Coordinator at the University of East Anglia (UEA), this internship provides a near-unique opportunity to connect research communities that are involved in both observational and experimental studies of ocean acidification. Cefas has a national role in providing marine advice and evidence to the Department of Environment, Food and Rural Affairs (Defra); it will therefore be able to use the information brought together by this internship as the basis for future national environmental status reports, and for European and international reporting.

UKOA will also be able to assist in disseminating the outcomes of the internship through its many international contacts, including those with the US (through the Ocean Acidification Program of the National Oceanographic and Atmospheric Administration); with ~30 other countries involved in ocean acidification measurements (through the Global Ocean Acidification Observing Network); and with UN bodies (including the Intergovernmental Oceanographic Commission of UNESCO, and the Convention on Biological Diversity).