Prof Hallegraeff is recognised nationally and internationally for his marine biosecurity work on harmful algal blooms impacting on human health, the fish farm and shellfish industries, their stimulation by coastal eutrophication and global spreading via ship's ballast water. He has published over 140 papers and 8 books, including a stage setting UNESCO Monograph on Oceanographic Methodology on Harmful Marine Microalgae. Working through agencies such as AQIS, BHP, IMO, UNESCO, SCOR and WHO his research has underpinned the development of technologies and monitoring strategies to manage and mitigate the impacts of harmful algal bloom outbreaks, and reduce their translocation via ship's ballast water.