||These data are counts of infauna derived from the analysis of 37 samples collected at The Canyons MCZ in May and June 2017 on board the RV Cefas Endeavour. It also includes marine litter data recorded on the SACFOR scale. Marine Conservation Zones (MCZs) are a new form of Marine Protected Area (MPAs) created under the Marine and Coastal Access Act 2009 which will protect a range of nationally important habitats and species. By protecting these species and habitats MCZs will contribute to a network of MPAs in the UK, together with existing MPAs (European Marine Sites, and marine elements of SSSIs and Ramsar sites) and other national designations being planned in Scotland, Wales and Northern Ireland. This means the MPA network will be a collection of areas that work together to provide more benefits than an individual area could on its own. Natural England and JNCC will provide detailed advice to Public Authorities on the sensitivity of MCZ habitats and species following designation. Sediment samples were processed to extract and identify all biota retained, following sieving at sea, on a 1.0mm capture mesh, as per the NMBAQC guidelines for extraction and identification (Worsfold et al, 2010, http://www.nmbaqcs.org/media/1175/nmbaqc-inv-prp-v10-june2010.pdf). Enumeration, identification and biomass per identified taxa was carried out following the Processing Requirement Protocol and Taxonomic Discrimination Protocol (Worsfold et al, 2010). Biomass was recorded as blotted wet weight in grams to at least 4 d.p. for all countable taxa. A single reference collection of all species / taxa encountered was delivered along with the faunal residues picked from the sediment sample.