Cetaceans in Greece: Present status of knowledge

Sightings from the core study area of long-term studies on short-beaked common dolphins
and common bottlenose dolphins in the inner east Ionian Sea (Bearzi et al. 2005, 2006) and
the Amvrakikos Gulf (Bearzi et al. 2008a) have not been used, since their high numbers
would create a very significant geographical unbalance in the dataset.
Caution is due to the interpretation of the number of sightings recorded per species (Table
1) since data include both opportunistic sightings and results of dedicated surveys that used
different methods (e.g. visual versus joint visual-acoustic surveys). Even more importantly,
some areas have been surveyed intensively or more systematically than others (Annex I,
Figure 2); others have not been surveyed at all. As a result the number of sightings recorded
per species is not directly indicative of the relative sighting frequencies in this study and the
relative presence/absence on the maps is not directly indicative of abundance.
Stranding data
Stranding data (including floating carcasses and incidentally caught animals) were obtained
mainly through the national stranding network established by the Hellenic Centre for Marine
Research in collaboration with the Port Police authorities. This network provided information
to various recipients (ministries, research centres and NGOs) during the period 1991-2002.
By 2002 the available information started being centralised at the Ministry of the Marine
Merchandise (YEN) from where copies of all records were obtained regularly. The network's
data cover the period September 1991 – December 2008, and derive from standardised
forms filled by local Port Police authorities. This network can not keep track of all the
stranding events and the number of unreported strandings – some of which were
incorporated to the dataset after becoming known through sources other than the network -
is not negligible, particularly in the early years and the period 2003-2004. The stranding
records used in this report originated from two independent databases. The database of
Pelagos Cetcean Research Institute contained 1263 records and the database of MOm
(Hellenic Society for the Study and Protection of the Monk Seal) contained 342 records. The
two databases were merged and duplicates were eliminated. Stranding data refer to number
of animals stranded and not to multiple stranding events (strandings of three or more
individuals were rare and concerned mainly Cuvier’s beaked whales).
The stranding data presented here may underreport smaller species, while large whales
(mainly fin whales and sperm whales, which are conspicuous and account for ‘exceptional’
events) were more likely to be reported. Since Port Police and local veterinarians may not
possess the expertise needed to correctly identify cetacean species, all information coming
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