Intertidal Monitoring of Sabellaria alveolata in Cardigan Bay Special Areas of Conservation (SACs) 2004 dataset https://portal.medin.org.uk/portal/start.php?tpc=007_NRW_DS101995 The Habitats Directive establishes that the management of Special Areas of Conservation (SACs) should aim to achieve the favourable conservation status of habitat and species features listed within its Annex I and Annex II. For SACs in Wales, the Countryside Council for Wales (CCW) is therefore required to report on a regular basis on whether features are in favourable conservation status. Honeycomb reef worm Sabellaria alveolata is a sedentary, tube-dwelling polychaete most commonly found on rocky substrata in the lower shore and shallow subtidal zones of marine and estuarine areas. The honeycomb reef worm is a UK BAP Priority Habitat (BAP habitats are now Habitats of Principal Importance/Priority Habitats). Honeycomb worms build tubes from sand and shell fragments. They are found on the lower part of rocky seashores but they also need a sand supply for tube-building. Dense congregations of Sabellaria alveolata tubes form large biogenic reef structures, which can be up to a metre thick and take the form of hummocks, sheets or more massive formations. The purpose of this data capture was to identify specific survey locations and to measure the extent of Sabellaria alveolata reef along agreed transects, and assess the quality of Sabellaria alveolata reef present and map and make notes on any sightings of wireweed Sargassum muticum. Confidence in this dataset is high as surveys were undertaken by experienced staff. 20081231