This dataset includes the survey data that were collected during the Marine Nature Conservation Review (MNCR) between 1987 and 1998, together with data from surveys commissioned by the Nature Conservancy Council in the 1970s and 1980s and data collected subsequently by JNCC. The MNCR was initiated to provide a comprehensive baseline of information on marine habitats and their associated species around the coast of Britain which would aid coastal zone and sea-use management and to contribute to the identification of areas of marine natural heritage importance. The focus of MNCR work was on benthic habitats (often referred to as 'biotopes') in intertidal and inshore (typically within 3nm) subtidal areas.