Harbour porpoises are the most abundant marine mammal in British and Irish shelf waters, and are widely distributed throughout coastal and shelf waters. They regularly enter bays and estuaries, but the extent to which they exhibit home ranges is unknown. Harbour porpoises are extremely difficult to observe in the wild, as they generally travel alone or in small groups, surface irregularly and have a small dorsal fin with a low profile. Their presence is much easier to detect acoustically, as they habitually echolocate to orientate themselves and locate their food. Researchers have exploited this fact by developing a variety of passive acoustic measuring tools, which monitor the ultra‐sonic frequencies that characterise porpoise echolocation clicks. One such tool that is widely used by researchers studying porpoises is a self‐contained click detector known as a ‘T‐Pod’ or ‘Pod’. T‐PODs have been used in the present study to assess the frequency with which porpoises use the Narrows and enter Strangford Lough. This series contains two reports, one of which is an update with additional monitoring results.
March 2010 Report
Interim Report - November 2010