Isles of Scilly Complex SAC: SEAGRASS BEDS

Descriptions

Description The area was designated as a Special Area of Conservation (SAC) for the following Annex 1 habitats as listed in the EU Habitats Directive (European Commission, 1992): • 1110 Sandbanks which are slightly covered by seawater all the time. • 1140 Mudflats and sandflats not covered by seawater at low tide. • 1170 Reefs Extensive subtidal seagrass beds are an important sub-feature of the ‘Sandbanks which are slightly covered by seawater all the time’ feature. There are a number of seagrass beds present within the Isles of Scilly Complex SAC, which are found on the sandbanks and sandflats within the shallow, sheltered bays between the islands. Following the decline of seagrass from wasting disease in many parts of the country since the 1930’s, the Isles of Scilly has become one of the most important areas nationally for beds of Zostera marina var. marina. However, even in Scilly, the once vast meadows which extended over hundreds of acres of sandflats (including intertidal areas) have largely been lost due to this disease (Harvey, 1969). Recovery has occurred to some extent but is still very limited in intertidal areas. The Isles of Scilly seagrass beds, however, remain some of the most extensive in southwest Britain, and are of national significance due to the rich associated flora and fauna. The JNCC Marine Monitoring Handbook (2001) states that the extent (ha) of seagrass is a key structural component of some sandbanks and provides a long-term integrated measure of environmental condition across the feature. Extent of the seagrass feature within the Isles of Scilly SAC was last monitored in 2009 (Jackson et al., 2011) and Natural England wishes to monitor seagrass extent in 2016 against that baseline in order to fulfil our requirements for reporting to Europe.