Killer whale photo-identification made easy
Photo-identification, a technique that uses photographs to identify individuals in animal populations through natural markings visible on their body is central for research on cetaceans and their interactions with fisheries. When applied to killer whales (Orcinus orca) involved in depredation-interactions, the technique has proved extremely useful to understand the impacts of these interactions on fishing activities, fish stocks and whale populations. This paper provides a simplified yet comprehensive protocol for implementing consistent photo-identification effort by observer or crews from fishing vessels experiencing depredation in the SIOFA area with limited costs and limited interference with existing workload. The key steps of this protocol include: • Setting gear in speed priority and high shutter speed (minimum 1/1000s) • Taking pictures of the dorsal fin, the saddle patch and the eye patch of killer whales when individuals come to the surface; • Taking as many pictures as possible (storage should not be a limit, tips for easy storage provided).