Changes in surface CO2 and ocean pH in ICES shelf sea ecosystems.

The primary purpose of this document is to report the recommendations resulting from the ICES WORKSHOP ON THE SIGNIFICANCE OF CHANGING OCEAN CO2 AND PH IN ICES SHELF SEA ECOSYSTEMS held between 2 and 4 May 2007 in London. Some excellent reports have already been published in this field, first by the Scientific Committee on Oceanic Research (SCOR; Arvidson, 2005), then by the National Oceanic and Atmospheric Administration/National Science Foundation/US Geological Survey (NOAA/NSF/USGS; Kleypas et al., 2006), the Royal Society (The Royal Society, 2005), the German Advisory Council on Global Change (WBGU; WBGU, 2006), and most recently by the OSPAR Commission (OSPAR, 2006) and the Intergovernmental Panel on Climate Change (IPCC; Metz et al., 2005). Cognizant of these recent efforts, the ICES Workshop set out with a slightly different aim to investigate the links between potential changes in pH and its effects on marine ecosystem components, such as plankton, fish and shellfish, and cold‐water corals. To this end, the Workshop covered ground already considered by others, to provide a sound base for the prediction of likely impacts. The present report will outline those relevant issues, but the reader is advised to refer to other reports for greater detail. The novel focus of this report is the potential effects on ecosystem functions with links to fisheries, with a recommendation for work to be done to better understand the impact of this problem on the entire ecosystem, and specifically on fisheries. Most of the material used was presented at the Workshop, with Annex 1 being the most significant exception.