DESCRIZIONE
A method for external fish parasite monitoring in aquaculture, comprising the steps of: - submerging a camera (52) in a sea pen containing fish, the camera having a field of view; - capturing images of the fish with the camera (52); and - identifying external fish parasite on the fish by analyzing the captured images, characterized in that a target region within the field of view of the camera (52) is illuminated from above and below with light of different intensities and/or spectral compositions.