A fish counting system (3) has: an image acquisition unit (30) for acquiring a plurality of images wherein a fluid containing fish is imaged over time; a counting unit (34) for counting the fish on the basis of the plurality of images; a fish count change display provision unit (38) for providing a fish count change display (70), wherein a display (71) corresponding to the number of fish counted per unit time is arranged in a time-series manner; a result provision unit (36) for providing a counting result display (60) wherein an image (62) to which count completion marks (61) indicating a counted fish have been added; and a correction unit (37) for receiving a correction operation and correcting the number of fish.