Wyre and Rousay Sounds MPA sits at the margin of the Atlantic and the North Sea. The tides squeeze between the islands of Rousay, Wyre and Egilsay creating perfect conditions for maerl beds and seaweed communities to thrive on the sandy seabed.
Maerl is a red seaweed with a hard, chalky skeleton. Where conditions are good, dense beds of maerl can form covering a large area and growing tens of centimetres deep. Larger animals such as gobies and crabs roam the maerl bed hunting for prey, and are themselves rich pickings for larger fish and diving seabirds. Kelps and red seaweeds anchor themselves to the maerl creating a mosaic of algal habitats. The seaweed coverage varies with the seasons just like the cover of plants on land, dying back in winter and being dislodged by storms. The kelps and seaweeds provide shelter for other small plants and animals. Sponges and sea squirts attach to the kelp holdfasts, claw-like structures which anchor them to the seabed.
Maerl beds also have a strong link to coastal habitats of the Orkney Islands. The MPA lies within the Orkney carbonate production area, an internationally important example of a non-tropical shelf carbonate system. Here the seabed habitats are high in calcium carbonate because they are made up of the dead eroded shells and skeletons of plants and small animals that once lived in or on the seabed such as bivalve molluscs and maerl. These sediments supply the sandy beaches around Orkney and are essential for the development of coastal machair; a rare habitat that supports diverse grassland vegetation which flowers in spring.
The current conservation objective is to conserve the protected features of this MPA.
More detail on the designation is available from the SNH website.
The final Business and Regulatory Impact Assessment for this MPA is available to view.