The United Nations forecasts that the population of the world will reach 9.8 billion by 2050. With many experts being concerned as how to feed so many people, fish farming is growing dramatically to fill the gap. As with any farming, growing large amounts of food in a small space increases the incidence of infection and disease can spread extremely rapidly. Andrew Monk of ioLight identifies how rapid diagnosis through mobile microscopes can fight against listed diseases and increase aquaculture productivity.