Ole-Kristian Hess-Erga is a microbial ecologist (PhD) from the Norwegian University for Science and Technology (NTNU) and employed as a research scientist at NIVA, Section for Fish Ecology and Aquaculture. Ole-Kristian is specialized in microbial ecology and water treatment, and has been working with the effects of disinfection, decomposition of organic matter, bacterial recolonization, and small-scale aquaculture since 2005. His work has focussed both on intensive aquaculture (biology and technology) and ballast water treatment. Ole-Kristian has additional experience from offshore work and shipping.