Cetaceans in Greece: Present status of knowledge

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Distribution and effort The distribution of all available records (Figure 3, Annex II) provides a reasonably good coverage of the Greek Seas and therefore, the geographic range given for each species is thought to represent a good approximation of the real figures. Nevertheless, much more effort is needed in order to obtain the precise distribution of each species. The absence of sightings in some geographical areas is in most cases the result of lack of survey effort (e.g the central and eastern Aegean). However, in some particular areas (Patraikos Gulf and inner Ionian Sea) the absence of sightings more accurately reflects the scarcity of cetacean presence. Figure 2 in Annex I provides the distribution of the searching effort so far and it is particularly useful in avoiding misinterpretation of the results of this report, as well as for planning future research effort. The cetacean species recorded in the Greek Seas can be divided in three major categories according to their distribution: a) the striped dolphin, the common bottlenose dolphin, the sperm whale and the Cuvier’s beaked whale are or seem to be present in the entire range of the bathymetry/habitat that is considered typical for them, b) the short-beaked common dolphin, the fin whale and the harbour porpoise present heterogeneous distributions within their potential habitats, c) the Risso’s dolphin can be predictably found in a small number of areas only, although its occurrence (as sightings or strandings) has been recorded in most geographical areas of the Greek Seas. Stranding data Eleven species have been identified within the stranding record (Table 1). The percentage of identified animals among 1352 strandings from 1991 to 2008 was 47%. As the vast majority (99%) of unidentified animals belonged almost exclusively to three delphinid species (common bottlenose dolphins, striped dolphins and short-beaked common dolphins), their percentages among identified animals are underestimated. Extrapolated numbers for these three species (see methods in section “Stranding data”) for the period 1996-2008 are presented in Table 1. The common bottlenose dolphin is the most common species among strandings (44.8%) followed by the striped dolphin (31.2%). Averages of ca. 34 and 23 stranded animals per year were recorded for these two dolphin species, respectively. The short-beaked common dolphin was found among strandings with an average rate of 9 stranded animals per year (11.7%). The occurrence of Cuvier’s beaked whale (5.5%) in the stranding record accounted for about four animals per year, but when atypical mass strandings were excluded this number was about two per year. The Risso’s dolphin (2.2%), the sperm whale (1.7%) and the harbour porpoise (1.5%) accounted for 16
about 1 to 1.5 strandings per year. Finally, the fin whale, the humpback whale and the common minke whale represented rare stranding events (less than 0.5% of the total strandings each). Mass strandings were relatively rare. Twenty-nine strandings involving more than one animal (couples, mass strandings sensu Geraci and Lounsbury 1993, or atypical mass strandings as described in Frantzis 1998) have been recorded during the period September 1991 – December 2008. Two previous mass strandings of four Cuvier’s beaked whales each have been recorded in 1987 and 1988. In 31 stranding events involving more than one individual, twelve cases (39%) concerned Cuvier’s beaked whales, four cases (13%) concerned striped dolphins, one case concerned sperm whales, one case (entanglement) concerned striped dolphins and a Risso’s dolphin, one case concerned common bottlenose dolphins and twelve cases (39%) concerned unidentified delphinids. The atypical mass stranding of fourteen Cuvier’s beaked whales in 1996 was linked with the use of military sonar during exercises (Frantzis 1998). Another atypical mass stranding of nine Cuvier’s beaked whales in 1997 could also be due to similar causes (Frantzis 2003). At least in two cases striped dolphins and unidentified small delphinids bore obvious anthropogenic wounds (inflicted by knives). In two other cases three dolphins were found dead in neighbouring sites of the same coast during the same day; an indication that they were either killed intentionally or by-caught. In the first case these were two short-beaked common dolphins and one unidentified small delphinid. In the second case all three dolphins were unidentified, but heir sizes (2.65, 2.80 and 2.90 m) suggest that they were probably common bottlenose dolphins since common dolphins and striped dolphins do not reach such lengths in the Mediterranean Sea (Notarbartolo di Sciara 1997, Aguilar 2000, Bompar 2000). All these cases concern strandings which involved more than one individual of dolphins bearing anthropogenic wounds. Many cases of single dolphins with signs of intentional killing have been reported, but most of them were impossible to confirm or reject due to the the low quality or the absence of photos. In at least two cases, striped dolphins stranded alive and showed behavioural symptoms similar to those presented by dolphins infected by the Mediterranean morbillivirus. No detailed data are available for the rest of strandings that involved more than one individual. 17
Page 1 and 2: Cetaceans in Greece: Present status
Page 3: Organisations supporting the Initia
Page 7: ORIGIN AND SCOPE OF THIS REPORT The
Page 10 and 11: According to the distribution maps
Page 12 and 13: not belong to the suborder of mysti
Page 14 and 15: Data collection Available cetacean
Page 16 and 17: from the network was initially cons
Page 20 and 21: Sighting data Ten cetacean species
Page 23: CETACEAN SPECIES COMMONLY OCCURRING
Page 26 and 27: Reported sightings and strandings T
Page 28 and 29: Main threats In the western Mediter
Page 32 and 33: published stomach content contained
Page 36 and 37: the stranding and death of several
Page 40 and 41: IUCN Red List classification Medite
Page 45 and 46: Drawing by Massimo Demma / ICRAM Ta
Page 47 and 48: Degree of residency and/or isolatio
Page 49 and 50: Drawing by Massimo Demma Taxonomy D
Page 51 and 52: a similar abundance. Short-beaked c
Page 53: 2008b). No information is available
Page 58 and 59: important: anchovy, sprat (Sprattus
Page 61 and 62: Megaptera novaeangliae (Borowski, 1
Page 63 and 64: Balaenoptera acutorostrata Lacépè
Page 69 and 70:
Steno bredanensis (G. Cuvier in Les
Page 71 and 72:
FALSE REPORTS OF CETACEAN SPECIES I
Page 73 and 74:
WHAT IS KNOWN, WHAT REMAINS UNKNOWN
Page 75 and 76:
ARE THE GREEK CETACEAN POPULATIONS
Page 77 and 78:
ACKNOWLEDGEMENTS Many thanks to sev
Page 79 and 80:
Bearzi G., Politi E., Agazzi S., Az
Page 81 and 82:
García-Martinez J., Barrio E., Rag
Page 83 and 84:
Notarbartolo di Sciara G., Demma M.
Page 85 and 86:
ANNEX I: Distribution of searching
Page 87 and 88:
Balaenoptera physalus FIN WHALE (Π
Page 89 and 90:
Ziphius cavirostris CUVIER’S BEAK
Page 91 and 92:
Tursiops truncatus COMMON BOTTLENOS
Page 93 and 94:
Delphinus delphis SHORT-BEAKED COMM
Page 95 and 96:
ANNEX III: Additional references on
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Cetaceans in Greece: Present status of knowledge

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