Small Isles NCMPA

Status: Designated


Site overview

This site is located around the islands of Canna and Rum off the west coast of Scotland, and is home to the only known aggregation of fan mussels in UK waters. The fan mussel is one of the most threatened molluscs in the UK and  grows to between 30 - 48 cm in length. It was believed that only occasional individuals survived around the coast of Scotland, until the discovery in 2009 of a large aggregation in the deep, tide-swept waters between Rum and Canna. The northern feather star is also found here, along with sea fans, dead man’s fingers, white cluster anemones and sponges. Small Isles MPA overlaps the Rum, and Canna and Sanday Special Protection Area (SPAs), designated in part to protect breeding seabirds. The sea here is used by a large breeding colony of black guillemots (more than 1,200 individuals).

At risk Management of this site has been delayed because of opposing concerns. This has meant that creatures such as fan mussel and northern feather star aggregations have possibly been damaged further. The fan mussel aggregation here is really rare, and the fan mussel status throughout Scottish seas is plainly critical. So this population needs to be given the chance to recover. 

MPA Type

Nature Conservation Marine Protected Area

Nature Conservation Marine Protected Areas (NCMPAs) are designated under UK legislation (Marine Scotland Act 2010) and have been established around Scotland to contribute to the UK MPA network by protecting a range of important habitats, species and features of the seabed.

Designation date

24 July 2014

Surface Area

803.52 km2 (310.24 mi.2)


294.65 km (183.09 mi.)

  • Northern feather star aggregations (Leptometra celtica)

    Areas where these amazing creatures, related to starfish and sea urchins have formed a dense groups on the sea bed.

  • Fan mussel aggregations (Atrina fragilis)

    One of Britain’s largest and most threatened molluscs. They are a two shelled  animals like common mussels, but can grow to nearly 50cm in length.  They live with the pointed end of their shell buried in the sediment on the seabed.

  • White cluster anemones (Parazoanthus anguicomus)

    A small colonial anemone about 25mm tall and 8mm wide. They are found growing on sponges, worm tubes, corals and stones. Generally occurs in deep water down to at least 400 m but also found in shallow coastal waters.

  • Black guillemot (Cepphus grylle)

    In summer an unmistakable black and white bird with bright red feet. In the winter it dulls to more subtle shades of grey and white. Black guillemots are usually found in ones and twos, scattered around rocky islets.

  • Burrowed mud

    Burrowed mud is a surprisingly important marine habitat which supports a rich community of animals.   There are the burrow-making animals that live within the mud itself, including fish, worms, brittlestars, crabs and shrimps.  Secondly, there are those a

  • Northern sea fan and sponge communities

    These are dense communities of northern sea fan’s, which are whitish or grey branching colonies of animals that look like little trees, and little cup corals about 2.5cm across. These communities are most often found on upward facing or vertical rock sur

  • Circalittoral sand and mud communities

    Sand and mud communities usually in depths of about 15-20m which are usually dominated by animal rather than plant life.

  • Horse mussel beds (Modiolus modiolus)

    Horse mussels are like the little mussels so common around our seashore only they are much larger – up to 20cm in length. They are usually found in small clumps or vast beds, partially buried in the seabed. These groups create a great habitat for lots of

  • Glaciated channels/troughs, glacial lineations, meltwater channels, moraines, streamlined bedforms

    Depressions in the seabed resulting from the scouring effect of grounded icebergs during the last ice age

  • Shelf deeps

    A large U-shaped valley or shelf deep formed by a glacier during the last ice age.

Did you know?…

Over half a million people have voiced their support for ‘marine protected area’ designation in the UK through our campaigns

To the shelf limits, Scotland has 61% of UK waters, of which 23% are now in existing or new ‘marine protected areas’

Over 500,000 records of undersea species and habitats have been collected by volunteer Seasearch divers