Scottish Natural Heritage Commissioned Report No. 354 Distribution, abundance and population structure of bottlenose dolphins in Scottish waters evidence of historic and contemporary exchange between Scottish and Irish waters. A high proportion of dolphins using the Moray Firth SAC in summer were also detected within east coast waters during winter. Passive acoustic monitoring highlighted that core areas within the SAC continued to be used during much of the winter, although at a lower level than that observed during the summer months. The following conclusions were reached: Photo-identification can provide a robust method for estimating the abundance of bottlenose dolphins throughout Scottish coastal waters. However, in areas such as the west coast, where animals are sparsely and unpredictably distributed, research surveys are best targeted through close collaboration with public reporting schemes. Only low numbers of bottlenose dolphins occur in Scottish coastal waters. Consequently, broad-scale systematic surveys provide limited power for detecting core-habitats either in winter or summer. However, this study has demonstrated that a combination of Passive Acoustic Monitoring and targeted photo-identification surveys can provide robust data on seasonal and inter- annual patterns of occurrence in particular coastal areas of interest. For further information on this project contact: Fiona Manson, Scottish Natural Heritage, Battleby, Redgorton, Perth, PH1 3EW Tel: 01738 458 641 or
[email protected] iv Acknowledgements This project was carried out as a collaboration between the University of Aberdeen, the University of St Andrews, the Scottish Association of Marine Science and the Hebridean Whale and Dolphin Trust. However, the success of many aspects of the project depended upon much wider collaboration with a range of different organisations.