Nature Conservation Marine Protected Area
United Kingdom: SCT
Loch Sween is complex in shape with a number of arms extending from a single large basin. Tidal movement through the main body of the loch and these narrow arms creates a variety of different physical conditions in which a diversity of habitats thrive. Deep still waters throughout the loch are home to dark, quiet mud habitats. Here large green volcano worms live in burrows beneath the seabed. The only physical evidence of their presence are impressive dome-shaped mounds on the surface of the mud created when they excrete the sediment they have ingested. The volcano worms share their muddy domain in the loch with other burrowing animals including Norway lobsters, shrimps, worms and burrowing gobies.
The tidal narrows at Taynish and Caol Scotnish provide the perfect environment for maerl beds. Maerl is a free-living, calcareous red seaweed. There are two types found in Scottish waters described as either pink branched twiglets or pink hedgehog stones. Both types occur at Taynish Narrows and Caol Scotnish in Loch Sween. The branched structure of the maerl creates a complex habitat in which many other species such as feather stars, scallops, sponges, crabs and fish can shelter. The rapids also support luxuriant stands of seaweeds interspersed amongst the maerl.
Native oyster are sprinkled throughout Loch Sween, as can be seen by the shells left on the beach by feasting otters. Once common in Scotland and supporting a grand shellfish industry, native oyster beds now only exist in a few scattered locations. The population within Loch Sween is considered to be of national importance.