Evidence of Inter-Regional Connectivity for Risso’s Dolphins in the Western Ionian Sea, Central Mediterranean Sea

This brief report is the first comparative study of a photo-identification catalogue of the Risso’s dolphins (Grampus griseus) in the Western Ionian Sea (Central Mediterranean Sea). The positive match of two photo-identified individuals observed in two neighbouring areas in different and non-consecutive years represents the first record of Risso’s dolphin re-sightings across two Ionian sub-regions. This suggests potential inter-regional connectivity for the species, as reported in other sub-regions of the Mediterranean basin. Further, this supports the hypothesis that Risso’s dolphins use a large home range with seasonally different critical habitats, as suggested in previous studies carried out in the Western Ionian Sea.