Tony Stebbing joined the Plymouth Marine Laboratory when it was founded in 1971, and spent his career there. He worked initially to develop bioassay techniques for pollution studies. His later discovery of the stimulatory effect of low concentrations of toxic substances ('hormesis') led him to establish for the first time a method to access the output of growth control mechanisms. The coordination of scientific programmes occupied the later years of his career, and he holds an Honorary Fellowship from PML, which has provided the opportunity to write an account of his research and its implications.