Dolphins in a scaled-down Mediterranean: The Gulf of Corinth's odontocetes
Bearzi, G.; Bonizzoni, S.; Santostasi, N.L.; Furey, N.B.; Eddy, L.; Valavanis, V.D.; Gimenez, O. (2016). Dolphins in a scaled-down Mediterranean: The Gulf of Corinth's odontocetes, in: Notarbartolo di Sciara, G. et al. Adv. Mar. Biol. 75: Mediterranean marine mammal ecology and conservation. Advances in Marine Biology, 75: pp. 297–331. https://dx.doi.org/10.1016/bs.amb.2016.07.003
In: Notarbartolo di Sciara, G.; Podestà, M.; Curry, B.E. (2016). Adv. Mar. Biol. 75: Mediterranean marine mammal ecology and conservation. Advances in Marine Biology, 75. Academic Press: London. ISBN 978-0-12-805152-8. XXX, 428 pp., more
In: Advances in Marine Biology. Academic Press: London, New York. ISSN 0065-2881; e-ISSN 2162-5875, more
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| Keywords |
Abundance
Conservation
Distribution
Ecology
Human impact
Delphinus delphis Linnaeus, 1758 [WoRMS]; Grampus griseus (G. Cuvier, 1812) [WoRMS]; Stenella coeruleoalba (Meyen, 1833) [WoRMS]; Tursiops truncatus (Montagu, 1821) [WoRMS]
MED, Greece, Corinth Gulf [Marine Regions]; MED, Mediterranean [Marine Regions]
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| Authors | | Top |
- Bearzi, G.
- Bonizzoni, S.
- Santostasi, N.L.
- Furey, N.B.
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- Eddy, L.
- Valavanis, V.D.
- Gimenez, O.
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| Abstract |
The Gulf of Corinth is a 2400-km(2) semi-enclosed inland system (a mediterraneus) in central Greece. Its continental shelf areas, steep bottom relief, and waters up to 500-900 m deep offer suitable habitat to neritic and pelagic species. We used photographic capture-recapture, distribution modelling, and direct observations to investigate the abundance, status, habitat preferences, movements, and group size of four odontocete species regularly observed in the Gulf, based on five years (2011-2015) of survey effort from small boats. Striped dolphins (Stenella coeruleoalba) are more abundant (1324 individuals, 95% CI 1158-1515) than was determined from previous estimates. Striped dolphins appear to be confined to the Gulf, where they favour deep and oligotrophic waters, and were encountered in single-species and mixed-species groups. Shortbeaked common dolphins (Delphinus delphis) (22 individuals, 95% CI 16-31), individuals with intermediate pigmentation (possibly striped/common dolphin hybrids) (55, 95% CI 36-83), and a single Risso's dolphin (Grampus griseus) were only encountered in mixed-species groups with striped dolphins. Short-beaked common dolphins constitute a discrete conservation unit (subpopulation), and based on the current estimate, would qualify as Critically Endangered according to International Union for the Conservation of Nature (IUCN) Red List criteria. Common bottlenose dolphins (Tursiops truncatus) (39 animals, 95% CI 33-47) occur in single-species groups; they prefer continental shelf waters and areas near fish farms in the northern sector, and several animals appear to move into and out of the Gulf. Additionally, we contribute records of marine fauna and an assessment of the fishing fleet operating in the Gulf. Our study shows that the importance of this vulnerable marine environment has been underestimated, and management action must be taken to mitigate human impact and ensure long-term protection. |
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