Tour Operators as a Tool to Improve Information on Data-Deficient Cetacean Species

Understanding the distribution and behaviour of species is crucial for ecosystem assessment and economic evaluations. Despite global research efforts, some cetacean species or populations remain data deficient. False killer whales (Pseudorca crassidens) are among these species, possibly due to their pelagic behaviour and high mobility. This study focused on the Azorean Archipelago, an ecologically rich region influenced by the Gulf Stream and North Atlantic Current, where false killer whales have been regularly observed over the last decade by the whale watching operators. Using opportunistic data collection from tourist operators, we established the first long-term study of false killer whales in the NE Atlantic Ocean. Results revealed sightings between April and October, with a peak from July to September. False killer whale groups were observed interacting with other species, particularly bottlenose dolphins (Tursiops truncatus). The photo-identification analysis produced an individual catalogue and identified associations between individuals and groups. Four of these animals presented dorsal fin injury patterns suggestive of interactions with fishing gear. Open population capture–recapture (openCR) models estimated a population of 198 individuals in the research area. This study demonstrates the importance of opportunistic data collection in understanding poorly studied species. The findings contribute insights into false killer whale presence, behaviour and potential threats in the studied region. Future research should expand to winter data collection, comprehensive fishery interaction studies and population dynamics assessments for effective conservation efforts.