It isn’t only cetaceans that our Marine Mammal Surveyors and Wildlife Officers are on the lookout for when they are at sea...
ORCA also record species of sharks, turtles and tuna, as well as those other marine mammals so common around the UK waters: seals. The topography of our island coastline makes it especially good habitat for seals and we have internationally important populations of both harbour and Atlantic grey seals. The west coast of Scotland and the Hebridean Islands is a strong hold for both species.
The larger grey seal is a globally rare species and 40% of the 350-400,000 population resides in the British Isles. Of that number, 90% can be found around the coasts of Scotland. Unlike the grey seals in my home counties of Devon and Cornwall, which generally use haul outs attached to the mainland coast and can therefore be easily observed, grey seals on the west coast of Scotland prefer to haul out on exposed islands and skerries on the western side of the Outer Hebrides and the outer islands of the Inner Hebrides. Heavily hunted throughout their history the grey seal was down to as few as 500 individuals in the UK by 1914 when the Grey Seal Act finally gave them protection.
The harbour seal (or common seal), whilst globally more numerous has been in decline in the UK in recent years particularly in the Northern Isles and East Coast of Scotland. Important numbers reside in the Hebrides but they conversely prefer the more sheltered east coast of the Outer Hebrides and the Inner Hebrides. It is certainly the harbour seal that I record most regularly here, so the UK and the West Coast of Scotland in particular is important habitat for both species. There are designated protected areas for both and last year I was lucky enough to help members of Scottish Natural Heritage with their breeding and moult counts for the Lismore Harbour Seal Special Area of Conservation (SAC), near to where I live in Oban.
For years the people of the Hebrides have lived closely with seals, and understandably that closeness has resulted in a rich folk lore, no doubt attributed as a result of the human like qualities that seals seem to exhibit. They have a habit of following people along coastlines, intriguingly studying the land based humans. Their call has been likened to that of a human baby. And their big dark eyes seem to weep and cry; an adaptation to remove the salt from their bodies that the Islanders would not have understood. The story of the Selkie (part human/part seal) is a common one and invariably involves shape shifting as the seal sheds its skin and walks amongst the people, often lured by a siren like woman who hides the skin so that the seal can’t return to the ocean and has to reside amongst the human population.
But in reality the mysterious life of the seal doesn’t need elaboration and fictionalizing. Seals are amazingly adapted animals living in an extreme environment. They can dive to depths, up to 300 metres, and to do this they shunt the oxygen into their blubber and muscles, expelling as much air as possible from the body. Because they use so much oxygen when diving they need to rest at the surface or hauled out on land to re-oxygenate their bodies, raise their heart rate, and remove excessive lactic acid from the body after bouts of feeding. Thus when seals are scared back into the water they are prevented from taking part in an important physiological process as well as risking injury on the rocks as they plunge back into the sea.
When hunting they have particularly good underwater vision which they utilize in good conditions. But in deeper and murky water they rely on their vibrissae (whiskers) to find their prey, which are so sensitive that they can sense the movement or even wake of their prey in the water.
It is certainly easy to overlook these incredible creatures that live in our midst and I try to refrain from lifting my head from my binoculars and saying, “oh its only a seal”. They definitely make a very good second best when cetaceans are thin on the ground. There is a particular grey seal that frequents the harbour in Mallaig that I can always count on. The locals tell me that he is called Sammy the Seal: but isn’t that what every semi habituated harbour dwelling seal is dubbed? I can recognize Sammy but I have yet to start to identify other individuals. Each seal is different and they have unique markings on their pelage that they can be identified by. It seems a shame that, considering how interwoven the lives of the Hebrides people has historically been with the seal clans, that we don’t have more of an understanding of the lives of some of the individuals here.
ORCA WIldlife Officer - Hebrides