The production of carbon dioxide, via the respiration of marine plankton, represents the largest sink in the global marine biological carbon cycle, is an important constraint on organic carbon supply to the deep ocean and a crucial component in the debate about the balance between autotrophy and heterotrophy in the open ocean. Direct measurement of plankton respiration is problematic, however recent improvements in methodology, the accumulation of a global database and forthcoming fieldwork opportunities, mean that we now have the resources available to determine the complex relationship between respiration rate, community structure and environmental conditions including nutrient availability. In a changing environment it is important to understand how increasing sea surface temperature, melting sea ice, ocean acidification, variable dust deposition and upwelling intensity will impact bacterial, algal and zooplankton respiration and so the balance between biological CO2 uptake and CO2 production.

This PhD project will involve meta data analysis and a combination of laboratory, coastal mesocosm and shipboard experiments to assess the influence of environmental factors such as temperature and organic and inorganic nutrient supply on the magnitude and variability of bacterial and plankton community respiration and so production of CO2. The project is suitable for students with an interest in microbial oceanography, marine ecology and biogeochemistry, and benefits from collaboration within national and international marine biogeochemical research programmes in the Atlantic and Arctic Oceans and European Shelf Seas. The successful student will have at least an upper second class degree in Marine Sciences, Ocean Sciences, Environmental Sciences, Biological Sciences or Ecology. Relevant project or work experience, and excellent writing, statistical and analytical skills would be an advantage. The student will receive a comprehensive training in research and transferable skills, and be expected to present their work at appropriate national and international conferences. Prior to shipboard fieldwork, the student will need to pass a medical and dental examination and attend a sea survival training course.

Robinson,C. (2008) Heterotrophic bacterial respiration. In: Microbial Ecology of the Oceans (2nd Edition. Ed. D.L.Kirchman).John Wiley & Sons, Inc.

Robinson,C. and Ramaiah,N. (2011) Microbial heterotrophic metabolic rates constrain the microbial carbon pump. In Microbial Carbon Pump in the Ocean, N. Jiao, F.Azam, S.Sanders, Eds. Supplement to Science 332(6031), 52-53

Robinson,C. and Williams,P.J.leB. (2005) Respiration and its measurement in surface marine waters. In: Respiration in Aquatic Ecosystems (Eds. P.A. del Giorgio & P.J.leB.Williams) OUP, Oxford pp.147-180

Robinson,C., Serret,P., Tilstone,G., Teira,E., Zubkov,M.V., Rees,A.P., Woodward,E.M.S. (2002) Plankton respiration in the Eastern Atlantic Ocean. Deep-Sea Research I 49 787-813

Robinson,C., Archer,S.D., Williams,P.J.leB. (1999) Microbial dynamics in coastal waters of East Antarctica: Plankton production and respiration. Marine Ecology Progress Series 180 23-36