This site has been selected for both land-based features (oak woodland) and marine features – mudflats and sandflats. These types of mudflats and sandflats are submerged at high tide and exposed at low tide, and they occur within estuaries, large shallow inlets and bays, the open coast and lagoonal inlets. This habitat type can be divided into three broad categories (clean sands, muddy sands and muds), although in practice there is a continuous gradation between them. Within this range the plant and animal communities present vary according to the type of sediment, its stability and the salinity of the water.  These habitats are home to numerous shellfish and worm species, which in turn provides an important feeding ground for seabirds and wildfowl.
Loch Moidart and Loch Shiel Woods SAC is also designated for the otter (Lutra lutra).
 Loch Moidart and Loch Shiel Woods site summary, JNCC