Podiadis, V. (1), Karpouzli, E. (2), Genov, T. (3), Sinischalci, F. (4), Verriopoulos, G. (5), Neofitou, C. (1) and Exadactylos, A. (1)
(1) University of Thessaly, School of Agricultural Sciences, Department of Agriculture, Animal Production and Aquatic Environment, N. Ionia, Volos 38446, Hellas, Greece; (2) University of Edinburgh, School of Geosciences, Drummond Street, EH8 9XP, Edinburgh, UK; (3) Morigenos – marine mammal research and conservation society, Jarska cesta 36/a, 1000 Ljubljana, Slovenia; (4) OCEANUS onlus, Via Nomentana 175, 00161 Roma, Italy; (5) University of Athens, School of Sciences, Faculty of Biology, Department of Zoology and Marine Biology, Panep/poli, 15701 Ilissia, Hellas, Greece
A cetacean survey across the Mediterranean sea was carried out in October/November 2003, from a 13m, auxiliary powered, sailing catamaran. The objective of the survey was to record cetacean species distribution and abundance, with the aim to contribute to existing information about cetaceans in the Mediterranean sea, for their effective conservation and management. A combination of passive acoustic methods and visual observations were employed, with particluar emphasis on the acoustic detection of the sperm whale (Physeter macrocephalus). A two-element stereophonic hydrophone array was towed on a 100 m cable behind the vessel, sensitive to frequencies between 100 Hz and 20 kHz. Acoustic detections were made by listening for one minute every fifteen minutes, allowing an index of abundance to be calculated for sperm whales. Visual observations were carried out concurent to the acoustic effort during the day, whenever the sea conditions allowed. During the survey sperm whales were detected acoustically on 39 occassions. There were a total of 36 sightings of six species; striped dolphin (Stenella coeruleoalba), Risso’s dolphin (Grampus griseus), short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus), long-finned pilot whale (Globicephala melas), and sperm whale (Physeter macrocephalus). The striped dolphin was the species encountered most frequently, followed by the short-beaked common dolphin. Sperm whales, bottlenose dolphins and long-finned pilot whales were seen twice, while Risso’s dolphins were encountered once. A mixed species association between striped dolphins, short-beaked common dolphins and Risso’s dolphins was also observed.