1. A method for estimating a total weight of a fish catch, comprising: capturing images of a fish catch; the fish catch having been received on a fishing vessel; identifying fishes in the image; identifying, for each of the fishes, a species to which the corresponding fish belongs; determining, from the images, lengths of fishes that are a part of the fish catch; determining, from the images, a volume occupied by the fish catch; and estimating the total weight of the fish catch based on the lengths of fishes and the volume occupied by the fish catch.