Common or Harbour Porpoise

A frequent sighting in the waters of Ramsey Sound and beyond are our resident pods of harbour porpoise. A small cousin of the dolphin, these are the UK’s smallest cetaceans, growing to a maximum 1.8m in length. They are one of only six species of porpoise in the world. They are tidal feeders, and so conditions around Pembrokeshire are ideal foraging ground for them. The porpoise are relatively shy cetaceans and show no interest in the boats at all but are quite used to us and, if watched sensitively, will go about their business in our presence.

They are relatively solitary and a pod can be as few as two or three animals, rarely more than eight, although they will congregate in much larger numbers when there is an abundant food source. We occasionally see up to thirty feeding in the Sound, although smaller numbers are more common. We don’t see them working together to herd fish, in the same way dolphins do, and consequently they will spend most of their time hunting, showing little inclination for play and social interaction. A recent paper reports they will forage nearly continuously day and night and attempt to catch up to 550 small fish every hour, with a 90% success rate. This incredibly fast metabolism has led to them being referred to as ‘aquatic shrews’.