Peter Smith holds an Emeritus Professorship of Microbiology in the National University of Ireland, Galway. He has over thirty years experience of research in the control of infectious diseases in aquaculture and has served as editor of the disease section of the journal Aquaculture. His particular interest has been in the issues raised by the therapeutic application of antimicrobial agents and he has published over 130 articles on these subjects. His work has concentrated on the environmental consequences of antimicrobial agent use and risks it may potentially represent for human health. In the last decade Professor Smith has played a major role in the promoting the development, harmonisation and validation of standardised antimicrobial susceptibility testing protocols that must be applied in aquaculture if the goals of prudent and rational use of these agents in aquaculture are to be achieved. He has also published extensively on the use of statistically based methods for establishing epidemiological cut-off values to interpret in-vitro susceptibility data. He has served as the chairman of the ad hoc Working Group set up by the Aquaculture Commission of OIE that drafted of those chapters of the Aquatic Code relating to antimicrobial agents. He is also a member of the Aquaculture Working Group of the Clinical and Laboratory Standards Institute that is charged with the development of antimicrobial susceptibility testing protocols for aquatic bacteria. He is also a member of the EUCAST Subcommittee addressing the setting of epidemiological cut-off values for MIC distributions.