Haig Fras

It is protected as a Special Area of Conservation (SAC) because of the diverse fauna developed in its bedrock reef habitat.

[5] The granite is thought to be cut by a swarm of basic dykes inferred from magnetic and seismic reflection data.

Jewel anemones (Corynactis viridis) and Devonshire cup corals (Caryophyllia smithii) are found at the top of the outcrop.

Mobile fauna observed include urchins such as Echinus esculentus, brittle stars and the squat lobster Munida.

[1] The area of the proposed SAC is 481 square kilometres (186 sq mi), which includes a margin of 330 metres (1,080 ft) around the mapped bedrock area, derived from the maximum water depth of 110 metres (360 ft) and an assumed length to depth ratio of a fishing warp (the cable used to tow the fishing gear) of 3:1.

Map of granite outcrops onshore and offshore southwest England
Devonshire cup corals are found at the top of the reef.