DESCRIZIONE
A system for external fish parasites monitoring in aquaculture, the system comprising: - a camera (52) suitable to be submerged in a sea pen suitable for containing comprising fish, the camera being arranged for capturing images of the fish; and - an electronic image processing system (86) configured for identifying external fish parasites on the fish by analyzing the captured images, wherein: - a ranging detector (54) configured for detecting the presence of fish and measuring a distance from the detector to the fish is mounted adjacent to the camera (52); and - an electronic control system (12) is arranged to control a focus of the camera (52) on the basis of the measured distance and to trigger the camera (52) when a fish has been detected within a predetermined distance range.