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Mediterranean and Black Sea Cetacean Red List Assessment
Tursiops truncatus ponticus
Population
The total population size is unknown. However, there are recent abundance estimates for parts of the
range, including the TSS, Kerch Strait, and Russian and Ukrainian territorial waters in the Black Sea (see
Table 1). These estimates suggest that population size is at least several 1000s. Population structure
within the Black Sea is likely, with several subpopulations (“semi-resident” communities), including those
that spend most of the year in geographically and ecologically different areas, e.g. northwestern Black
Sea; coastal waters off southern Crimea; Kerch Strait and adjoining portions of the Black Sea and Azov
Sea; shelf waters off the Caucasian coast; Turkish Black Sea; and TSS.
Population Trend
– until 1983 (directed killing reduced the population)
? – 1983–2005
? – 2006 and beyond
Detailed Documentation
Range and Population
Range: The range of Black Sea bottlenose dolphins includes the Black Sea proper; Kerch Strait along
with the adjoining part of the Azov Sea (Tzalkin 1940; Birkun et al. 1997; Sokolov 1997); and the Turkish
Straits System (TSS) (Kleinenberg 1956; Beaubrun 1995; Öztürk and Öztürk 1997). The genetic data
suggest that the TSS constitutes an ecological barrier between the Black Sea dolphins and those in the
Mediterranean, although limited gene flow between the two seas is probable. A possible vagrant from the
Black Sea population was identified genetically in the western Mediterranean (Natoli et al. 2005).
The range of the Black Sea subspecies includes the 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, Karkinitsky Bay and Donuzlav Lake); internal
waters of Russia and Ukraine in the Kerch Strait and Azov Sea; and internal waters of Turkey including the
Bosphorus Strait, Marmara Sea and Dardanelles. There are a few records of bottlenose dolphins entering
rivers, e.g. the Danube in Romania (Police 1930, fide Tomilin 1957) and the Dnieper in Ukraine (Birkun
2006).
Population structure within the Black Sea is likely (Bel’kovich 1996), with several subpopulations or “semiresident”
communities, including those that spend most of the year in geographically and ecologically
different areas, e.g. northwestern Black Sea; coastal waters off the southern Crimea; Kerch Strait and
adjoining portions of the Black Sea and Azov Sea; shelf waters off the Caucasian coast; Turkish Black
Sea; and TSS.
Abundance: The total population size is unknown. Region-wide estimates of absolute abundance, based
on strip transect surveys carried out in the USSR (1967-1974) and Turkey (1987), have been discredited
by the IWC Scientific Committee due to irremediable methodological and interpretive problems (Smith
1982; Buckland et al. 1992). During most of the 20th century, the bottlenose dolphin was considered the
least abundant of the three cetacean species in the Black Sea (Zalkin 1940; Kleinenberg 1956; Geptner et
al. 1976; Yaskin and Yukhov 1997). During the last decade, bottlenose dolphins have become prevalent
in coastal waters of the northern Black Sea (Birkun et al. 2004b). The estimated sighting rate increased
by a factor of five between 1995 and 1997-1998. There is an annual autumn accumulation of bottlenose
dolphins in waters close to the southern extremity of the Crimea (Cape Fiolent – Cape Sarych). Groups
of hundreds of animals migrate every autumn to this relatively small area from the eastern and, probably,
other parts of the Black Sea (Birkun et al. 2004b; Birkun 2006). Estimates of abundance from recent line
transect surveys in different parts of the range (Table 1) suggest that present population size is not less
than several 1000s.
Annex 3: Regular Species
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