Occurrence of Cuvier's beaked whales in the southern Adriatic Sea: evidence of an important Mediterranean habitat

Abstract

The intent of this work is to summarize the available knowledge on the appearance, identification and distribution of Cuvier's beaked whales (Ziphius cavirostris) in the Adriatic Sea through a review of historical data, inspection of natural history collections and collection of original data. In total, eleven occurrences are documented of Cuvier's beaked whale along the Adriatic coast with all records originating from the deep southern Adriatic basin. The number of recorded stranded Cuvier's beaked whales in the southern Adriatic represents about 3% of the recorded specimens in the entire Mediterranean. This percentage increases up to about 5% when considering only data collected after the first recorded stranding of the recent era in 1975. Comparing these percentages to the extent of the area relative to the Mediterranean, the proportion of occurrence of the total stranded Cuvier's beaked whales in the southern Adriatic ranged between the same to double of that of the entire Mediterranean Sea. Therefore, the southern Adriatic Sea should be considered as a potentially relevant habitat of the Cuvier's beaked whale. This hypothesis has clear conservation implications particularly in view of the adverse impact of sonar experiments, carried out by navies from several countries, on this species and should be further investigated. Finally, there is no evidence of the northern bottlenose whale (Hyperoodon ampullatus) ever having occurred in this part of the Mediterranean region.