Bottlenose Dolphin and Harbour Porpoise Monitoring in Cardigan Bay and Pen Llyn ar Sarnau Special Areas of Conservation (SAC) dataset https://portal.medin.org.uk/portal/start.php?tpc=007_NRW_DS115169 A population of bottlenose dolphins forms a primary interest of Cardigan Bay and it was for this that Cardigan Bay was first selected as a Special Area of Conservation (SAC). Cardigan Bay is known to host the largest population of semi-resident bottlenose dolphins in the UK. The data collected as part of this research is being used to monitor the population dynamics and behaviour of bottlenose dolphins and harbour porpoises in Cardigan Bay. Cardigan Bay is known to host the largest population of semi-resident bottlenose dolphins in the UK. This data covers monitoring carried out by the Sea Watch Foundation between 2011-2013 on behalf of the Countryside Council for Wales (CCW) and subsequently Natural Resources Wales (NRW), to monitor bottlenose dolphin and harbour porpoise populations in Cardigan Bay. The goal of this data collection was to monitor bottlenose dolphin and harbour porpoise populations in Cardigan Bay. The aims were to: - Provide information on the condition of bottlenose dolphins and harbour porpoises in Cardigan Bay including Cardigan Bay and Pen Llyn a'r Sarnau Special Areas of Conservation; - To use photo-identification techniques to evaluate dolphin movements distribution and abundance; - To assess supporting habitats. 20140331