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Methods
All cetacean species were assessed in 1996 against the 1994 criteria (Baillie and Groombridge 1996), and
some species, subspecies and geographical populations (‘subpopulations’) have been reassessed since then
against the 2001 criteria (see Reeves et al. 2003: their Table 1.1; also http://www.redlist.org). As explained in the
Guidelines for Application of IUCN Red List Criteria at Regional Levels (http://www.iucn.org/themes/ssc/redlists/
regionalguidelines.htm; also see Gärdenfors et al. 2001), listing of a species at the global population level can
differ from listings at the subspecies or ‘subpopulation’ level.
The scope of the present workshop was defined and delimited on a geographical basis, with the intent to assess
the status of all cetaceans in the Mediterranean and Black Seas, some of which constitute endemic subspecies
and others of which form geographically distinct ‘subpopulations’. For some or many of the species considered,
an uncertain amount of genetic and/or demographic interchange with populations in the North Atlantic was either
known or suspected to occur. ‘Units for assessment’ were therefore considered on a species-by-species basis.
The decision to conduct complete assessments for 12 of these units was made on the basis of prior knowledge,
as summarised by Notarbartolo di Sciara (2002). The Mediterranean subpopulation of Short-beaked Common
Dolphins had already been assessed against the 2001 criteria and therefore was not reassessed (Bearzi 2003;
see Annex 7). In addition to the eleven new complete assessments, available information on five ‘visitor’ 1 species
(Common Minke Whale, Humpback Whale, Killer Whale, False Killer Whale and Rough-toothed Dolphin; see
Annex 4), eight ‘vagrant’ 2 species (Sei Whale, North Atlantic Right Whale, Northern Bottlenose Whale, Dwarf
Sperm Whale, Sowerby’s Beaked Whale, Blainville’s Beaked Whale, Gervais’ Beaked Whale and Indo-Pacific
Humpback Dolphin; see Annex 5) and one introduced species (Beluga; see Annex 6) was summarised as
background for this report. Information on visitor and vagrant species is limited to occurrences within the Black
and Mediterranean Seas, including the western entrance to the Strait of Gibraltar up to a line between Cape
Trafalgar, Spain (36° 10’ 57.34” N, 006° 02’ 00.80” W), and Cape Spartel, Morocco (35° 47’ 27.88” N, 005° 55’
33.06” W). Finally, a brief account is given in Annex 8 of species that have been reported in the region but for
which such reports are considered invalid or doubtful.
IUCN criteria refer to reproductively mature individuals in a given population and it is therefore essential to use
this measure rather than total population size. Reliable data and analyses of vital rates are generally unavailable
for the populations of cetaceans in the Mediterranean and Black Seas. Therefore, the workshop made use of
a draft table of “default” values prepared by Barbara L. Taylor of the Southwest Fisheries Science Center in La
Jolla, California (pers. comm.). Based on her preliminary calculations and consistent with the views of workshop
participants, 20 years was accepted as a sensible round number to use, at least provisionally, as the default
generation time for dolphins.
1 A taxon that does not reproduce within a region but regularly occurs within its boundaries either now or during
some period of the last century (IUCN 2003).
2 A taxon that is currently found only occasionally within the boundaries of a region (IUCN 2003).
2