Horse mussel beds - Modiolus modiolus beds with fine hydroids and large solitary ascidians on very sheltered circalittoral mixed substrata (Priority Marine Feature) (SNH WMS)

The Priority Marine Feature (PMF) list contains 81 habitats and species considered to be of conservation importance in Scotland's seas. It includes many features which are characteristic of the Scottish marine environment, ranging from flame shell beds in coastal waters, to cold-water coral reefs of the deeper seas, and mobile species such as minke whale and basking shark.

This layer shows the distribution of Horse mussel (Modiolus modiolus) beds with fine hydroids and large solitary ascidians on very sheltered circalittoral mixed substrata. These are typically at depths of between 5-30m in very sheltered conditions, the mussel beds support a variety of brittlestars, scallops, crabs and gastropods. Found in Shetland, Orkney, the Hebrides and west coast sea lochs, it is not found anywhere else outside Scotland.