1. UK Ocean Acidification The Sea Surface Consortium is one of seven multi-partner consortium projects making up the UK Ocean Acidification research programme (UKOA) which integrates the research of over 120 scientists in 26 research laboratories across the UK. Further information on all the consortia is available from the UKOA website www.oceanacidification.org.uk. UKOA enquiries to Dr Phil Williamson (p.williamson.uea.ac.uk) the Science Coordinator or Dr Carol Turley (ct@pml.ac.uk) the Knowledge Exchange Coordinator. Contact : Consortium Coordinator Toby Tyrrell Ocean and Earth Sciences National Oceanography Centre, Southampton T.Tyrrell@soton.ac.uk Project and Knowledge Exchange Officer Athena Drakou Ocean and Earth Sciences National Oceanography Centre, Southampton a.drakou@soton.ac.uk www.surfaceoa.org.uk Funded by: Consortium objectives: To ascertain the impact of OA on planktonic organisms (in terms of physiological impacts, morphology, population abundances and community composition). To quantify the impacts of OA on biogeochemical processes affecting the ocean carbon cycle (both directly and indirectly, such as via availability of biolimiting nutrients). To quantify the impacts of OA on the sir-sea flux of climate active gases (DMS and N 2 O in particular. Most of the consortium’s planned work will be carried out on three cruises to locations with naturally strong gradients in seawater carbon chemistry and pH. The first of three research cruises took place on RRS Discovery, 6 June –9 July 2011, supported by the UK OA research programme. The cruise covered a wide range of environmental conditions around the UK and involved: 70 CTD stations (1500 Niskins) 320 underway sampling points 5 bioassay experiments (350 bottles) 1000 FC sampling points 2 tonnes seawater filtered Analyses of data and samples are in progress, with additional laboratory experiments. Most of the consortium’s planned work will be carried out on three cruises to locations with naturally strong gradients in seawater carbon chemistry and pH. The first of three research cruises took place on RRS Discovery, 6 June –9 July 2011, supported by the UK OA research programme. The cruise covered a wide range of environmental conditions around the UK and involved: 70 CTD stations (1500 Niskins) 320 underway sampling points 5 bioassay experiments (350 bottles) 1000 FC sampling points 2 tonnes seawater filtered Analyses of data and samples are in progress, with additional laboratory experiments. Our approach to studying OA Effects on Plankton and the Surface Ocean We propose a combination of observational and experimental (ship-board and land based CO2 perturbation) bioassays, thus filling a clear gap of previous and ongoing work with other international research. Method We bring volumes of natural seawater from the ocean surface and place them in customised laboratory container on deck, and there subject the organisms within to higher CO 2 and other stressors such as altered temperature and/or nutrients. We monitor the changes that take place within these natural communities as the seawater acidity is increased to controlled levels that may be expected in the future oceans at current CO 2 emission rates. We include the natural environmental variability and complexity that is difficult or impossible to capture in laboratory experiments. We measure these controlled experiments on the naturally-occurring community, thus representing more accurately the future response of the surface ocean to acidification. Method We bring volumes of natural seawater from the ocean surface and place them in customised laboratory container on deck, and there subject the organisms within to higher CO 2 and other stressors such as altered temperature and/or nutrients. We monitor the changes that take place within these natural communities as the seawater acidity is increased to controlled levels that may be expected in the future oceans at current CO 2 emission rates. We include the natural environmental variability and complexity that is difficult or impossible to capture in laboratory experiments. We measure these controlled experiments on the naturally-occurring community, thus representing more accurately the future response of the surface ocean to acidification.