Barbara Nowak is an outstanding international leader in the field of aquatic animal health. Her research on the effects of pollutants and environmental factors on fish diseases has substantially advanced understanding of fish health and contributed to sustainable aquaculture. Parasite management strategies proposed by her research have reduced tuna losses. Together with her Norwegian collaborators, she discovered a new type of lymphoid tissue in salmon gills, redefining directions in fish immunology. She has developed methods used worldwide to assess fish health and investigate fish diseases. Nowak has been recognised for her research through international invitations and awards.