Bottlenose Dolphin

The Bottlenose Dolphin (Tursiops truncatus) is found in both inshore and offshore waters of temperate and tropical regions throughout the Pacific, Indian and Atlantic Oceans. It is probably the best-known dolphin due to its frequent appearance in the nature and general interest media. This species has been recorded all around the Irish coast and far offshore but has been most often encountered close to land.

Bottlenose Dolphins range in length up to 4.2 metres and have an average weight of approximately 200 kilograms. Their colouration is generally a uniform grey with a lighter underside. The body and dorsal fins of bottlenose dolphins are often marked by scratches and scrapes from interactions with other dolphins. The jaw is elongated and bears a characteristic "smile". This species can be differentiated from other dolphin species by its large size, colouration and behaviour. Most calves are born during the summer months and stay with the mother for several years.

Although this species is recorded all around the Irish coast a distinct and resident population has been observed close to the mouth of the River Shannon for several hundred years. For this reason the Lower River Shannon has been designated as a Special Area of Conservation (SAC) for this species. The latest population estimate for the Shannon Dolphins has indicated that approximately 140 dolphins use this site although the numbers vary depending on the time of year. The most recent and previous studies show a trend of increasing numbers using the Lower River Shannon over the last decade. Two distinct sites have been identified as being important: at the mouth of the SAC near Ballybunion Bank and an area between Tarbert, Co Clare and Kilimer, Co. Clare. Strict guidance, which all licensed tour-boat operators within the region must adhere to, covers the methods and time allowed with dolphin groups within the Lower River Shannon. This guidance has been designed to allow the public to appreciate these animals whilst ensuring that the population continues to live relatively undisturbed in the area. Smaller apparently resident groups of bottlenose dolphins have been seen regularly at both outer Cork Harbour and the area around north Connemara, Co Galway.

Bottlenose Dolphin I Bottlenose Dolphin II
(Photos: NPWS)  


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