Except by a small number of sport divers and keen enthusiasts, the wonders of our underwater coast surrounding the island go relatively unexplored. Below the waves lives a vast array of creatures, thriving in the diverse habitats from lush green laminarian kelp forests, to the crashing turbulent waters around our cliffs. Kelp forests, which consists of large kelp plants (large brown seaweeds really) such as oarweed, cuvie and dabberlocks, have been described as the Scottish equivalent of the tropical coral reefs as they provide a three-dimensional living space for many organisms, from starfish and sea anemones to sponges and sea squirts. And here in these rich feeding areas, European otters and black guillemots forage for fish and crabs. You can get a glimpse of this underwater world from the shore if you peer into any rock pool (Harris is especially good); here you will see a variety of animals, some of which cannot survive drying out at low tide.
Here on Rum you’re never far from the sea, so if your walk takes you out near the coast, keep an eye out for the larger marine specialties of the area, including the second largest fish in the world, the basking shark. Depending on the year, this species is sometimes quite abundant in the sheltered bays and inlets as it feeds close to the surface.
One or two sightings of the bizarre looking sunfish are recorded most years. This is a warm water species that migrates northward to take advantage of jellyfish blooms as summer sea temperatures rise. It has the appearance of a flattened disc and has no real real tail and can reach up to 11 feet. Both grey and common seals are also quite abundant around the coast, with Loch Scresort, Caves Bay and Papadil being good places to watch for them.
Our ferry, the MV Loch Nevis makes a great platform on which to observe the many cetaceans (whales and dolphins) that are usually found around the Rum coast in the summer months, so keep a keen eye out on your voyage to and from the island. Minke whales, which can measure up to 7-9 metres are fairly abundant most years, as are short- beaked common dolphins and harbour porpoise. Pods of bottle-nosed dolphins are not infrequent either most years and a few orcas or killer whales are observed most years too. Rarer species which are sometimes spotted in the waters around the Small Isles include Risso’s dolphin, Atlantic white-sided dolphin and humpback whale. Please see our Ranger Service section regarding guided sealife boat trips. Also, check out recent cetacean sightings in the area on the Hebridean Whale and Dolphin Trust website.
During underwater surveys by Marine Scotland in the Sound of Canna (west side of the island), 100 individuals of the extremely endangered fan mussel and other priority marine features, such as northern feather star and burrowing anemone have been discovered recently. These species are particularly vulnerable from the damaging activities from trawl netting. As the Scottish Government have been identifying sites for Marine Protected Area (MPA) status under the Marine (Scotland) Act, these finds practically assure MPA protection for part of our coast in the near future from. Please see our News Section for further information.