The subspecies’ range includes the Black Sea proper, Azov Sea, Kerch Strait (e.g., Tzalkin 1938), Marmara Sea, Bosphorus Strait (Öztürk and Öztürk 1997), northern Aegean Sea (Frantzis et al. 2001) and also, very likely, the Dardanelles Straits (Harun Guclusoy 2006, pers. comm. to Frantzis) connecting the Marmara and northern Aegean Seas (see Figure 1 in attached PDF). The Black Sea population is completely isolated from the nearest P. phocoena population in the northeastern Atlantic by a wide range hiatus in the Mediterranean Sea (Frantzis et al. 2001). Although there is no agreement on when it happened (Kleinenberg 1956, Frantzis et al. 2001), it is clear that Harbour Porpoises came to the Black Sea via the Mediterranean which, therefore, must have had its own population in the past.

The range of the Black Sea subspecies includes territorial waters and exclusive economic zones of Bulgaria, Georgia, Romania, Russia, Turkey and Ukraine in the Black Sea; internal waters of Ukraine in the Black Sea (including the Dnieper-and-Boug Liman and Karkinitsky Bay); internal waters of Russia and Ukraine in the Azov Sea and Kerch Strait; internal waters of Turkey (TSS, including the Bosphorus Strait, Marmara Sea and, possibly, the Dardanelles); Greek territorial waters in the northern Aegean Sea (Thracian Sea, Kavala Gulf, Strymonikos Gulf, Agiou Orous Gulf, and Thermaikos Gulf); and possibly Turkish territorial waters of the northeastern Aegean Sea, at the exit of the Dardanelles Straits. Occasionally, Harbour Porpoises have been sighted in the Danube, Dnieper, Don and Kuban rivers, their estuaries, deltas and tributaries (e.g., in the Danube in 1984-1989 and 2003 or in the Ingulets, a confluent of the Dnieper, in 1999), and coastal freshwater, brackish and saline lakes and lagoons including the Yalpug and Sivash lakes, Berezansky and Grigorievsky lagoons, Tendrovsky, Yagorlytsky and Jarylgachsky bays, and the Gulf of Taganrog (Tzalkin 1940a, Geptner et al. 1976, Birkun 2006). All of these sites are situated in Ukraine and Russia, on the northern and northwestern coasts of the Black Sea and round the AzovSea.

The population of P. p. relicta may consist of three or more subpopulations including those that spend much of the year in geographically and ecologically different areas, e.g. the AzovSea, northwestern Black Sea and Sea of Marmara. The BosporusStraits, the Sea of Marmara and the DardanellesStraits serve as conduits between the Black and AegeanSeas. Water flow at the surface is into the Aegean, from the Black Sea (Poulos et al. 1997). If porpoises were to leave the Black Sea, the conditions in the northern Aegean Sea (as compared to other parts of the Mediterranean) would remain similar to those of the Black Sea. The period of greatest similarity would be February and March (Poulos et al. 1997) and five out of the nine records from the Aegean occurred from mid January to the end of March (three were in summer and one in October; all age classes have been found in the small available sample). Further work is needed to determine whether the animals found in the northern Aegean Sea represent a separate resident subpopulation.

[Definition: Territorial waters of all six Black Sea countries are defined as consisting of the 12-mile-wide submerged strip along the coast, and the offshore border of this strip constitutes the marine boundary for each country. In areas where the sea extends inland (gulfs, bays, etc.), the 12-mile rule does not apply. These water bodies constitute the so-called “internal (marine) waters” of the Black Sea countries.]