Occurrence of Physeter macrocephalus and Ziphius cavirostris in the North Ikaria Basin, Aegean Sea

The presence of two of the eight regular cetaceans of the Mediterranean Sea, the sperm whale (Physeter macrocephalus) and Cuvier's beaked whale (Ziphius cavirostris) is well-documented in the Western and Central Mediterranean Sea. In contrast, little information is available on their distribution in the Eastern Mediterranean, especially in the North Ikaria Basin (Greece), an underestimated important habitat for both species. Seasonal opportunistic visual surveys were conducted in this area from 2017 to 2019 to investigate their distribution. Out of 16 surveys, 4 sightings of P. macrocephalus and 2 sightings of Z. cavirostris were recorded. This is the first published, confirmed visual record of Z. cavirostris in this area. The documentation of both species in this preliminary study represents a significant contribution to consider efficient conservation action in this important area.