Dr Paul del Giorgio is an Associate Professor in the Department of Biological Sciences at the University of Quebec, Montreal, Canada.
Professor Peter J. LeB. Williams BSc PhD DSc (Birm) is Professor of Marine Biogeochemistry at the University of Wales, Bangor, UK. His research spans the fields of marine chemistry, biogeochemistry and microbiology. His particular interests are the quantification of respiration in the marine plankton, its distribution within the various planktonic groups, the links with photosynthesis and the control of respiration rates.