Occurrence and present status of coastal dolphins (Delphinus delphis and Tursiops truncatus) in the eastern Ionian Sea

摘要: 1. Boat surveys aimed at studying short-beaked common dolphins and bottlenose in eastern Ionian Sea coastal waters were conducted between 1993 2003. During 835 survey days, 24 771 km of total effort was distributed within an area 480 km2, resulting 428 dolphin 235 sightings. 2. Individual photo-identification performed extensively throughout this study, making it possible to monitor the number animals seen study each year their long-term residency patterns. 3. Common declined across period, from 2.18 encounters/100 1997 0.40 In contrast, there a relatively stable presence dolphins, some individuals showing high levels site fidelity others using only occasionally. 4. The local decline low density appeared reflect general status these cetacean species wider Mediterranean region, where classified as endangered IUCN Red List 2003. 5. Based on available evidence, we infer that present unfavourable is largely consequence prey depletion. Copyright © 2005 John Wiley & Sons, Ltd.