Lists of 'species and habitats of principal importance' have been draw up across the UK's devolved administrations. The lists are a requirement under the 'duty to conserve biodiversity' placed on public authorities under Section 41 in England and Section 42 in Wales of the Natural Environment and Rural Communities(NERC) Act 2006, Section 2(4) of the Nature Conservation (Scotland) Act 2004, and Section 3(1) of the Wildlife and Natural Environment Act (Northern Ireland) 2011. The resultant lists include species and habitats of 'principal importance' in England, Wales and Northern Ireland, and the Scottish Biodiversity List (in Scotland). Further detail: JNCC
Available MarLIN information on species listed as 'species of prinicpal importance' is listed below, based on the JNCC Taxon designations list 2014.