Bangor University School of Ocean Science (SOS) Survey of Sabellaria Reefs at Criccieth North Wales (2001) (3rd Party Data) dataset https://portal.medin.org.uk/portal/start.php?tpc=007_EXT_DS112862 UK Biodiversity Action Plan (BAP) priority habitats cover a wide range of semi-natural habitat types, and were those that were identified as being the most threatened and requiring conservation action under the UK Biodiversity Action Plan (UK BAP). The UK BAP habitats and species lists have been used to draw statutory lists of priority habitats as required under Section 42 of the Natural Environmental and Rural Communities (NERC) Act 2006. Sabellaria alveolata reefs are formed by the honeycomb worm Sabellaria alveolata, a polychaete which constructs tubes in tightly packed masses with a distinctive honeycomb-like appearance. These reefs can be up to 30 or even 50 cm thick and take the form of hummocks, sheets or more massive formations. Reefs are mainly found on the bottom third of the shore, but may reach mean high water of neap tides and extend into the shallow subtidal in places. Few studies have directly examined the S.alveolata associated communities and the majority of which, were conducted abroad. Studies have been undertaken using quantitative sampling of algae and epifaunal communities, studying reefs around the UK, however, no examination was made of infauna. This dataset is made up of the results of an investigation into the faunal and floral communities associated with intertidal Sabellaria alveolata reefs at Criccieth, North Wales. The aims of the study were to provide further information regarding the dynamics of the flora/epifauna and infauna communities associated with S. alveolata reefs in the UK. 20011231