4b76ee69-0073-4545-9f1b-006ca61f8f4a English series series The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk pointOfContact 2025-03-24 MEDIN 3.1.2 EPSG Geodetic Parameter Registry 2021-01-06 revision WGS 84 2022, North West Wildlife Trust, Marine Internships, Marine Net Gain Research and Evidence Project 2022-12-30 publication 2022-12-02 revision 2022-12-02 creation MDE-195-4141 This report was produced as part of the Marine Futures Internship, a collaborative project between Natural England, Ørsted, The Crown Estate, and the North West Wildlife Trusts, funded by The Crown Estate and managed by Cumbria Wildlife Trust. The project aims to support the UK Governments development of the "Marine Net Gain" (MNG) policy, which requires developers to leave marine biodiversity in a better state than before development. This policy is crucial for expanding the offshore renewable energy sector whilst aiding marine nature recovery. Using data from the Walney Extension Offshore Wind Farm, the report tests various scenarios to highlight the advantages and challenges of using a metric to calculate biodiversity value in marine environments. It identifies key issues such as the scarcity of knowledge on marine habitats, the difficulty of restoring marine environments, and the need for strategic significance in habitat restoration. The report provides recommendations for improving the metric and suggests involving developers and stakeholders in its development to ensure a smooth transition into policy. The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk owner The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk custodian The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk originator The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk distributor notPlanned Marine Environmental Data and Information Network MEDIN metadata record availability 2025-03-24 revision Environmental monitoring facilities GEMET - INSPIRE themes, version 1.0 2021-09-28 revision Biodiversity indices Habitat characterisation Man-made structures SeaDataNet Parameter Discovery Vocabulary 2021-09-28 revision otherRestrictions https://www.marinedataexchange.co.uk/content/info/terms-of-use otherRestrictions Publically Available English 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646 biota environment structure -8.0419921875 3.9990234375 49.745781306156 60.125091693362 SeaVox salt and freshwater body gazetteer 2021-01-06 creation Celtic Sea SeaVox salt and freshwater body gazetteer 2021-01-06 creation English Channel SeaVox salt and freshwater body gazetteer 2021-01-06 creation Irish Sea SeaVox salt and freshwater body gazetteer 2021-01-06 creation North Sea 2022-06-07 2022-12-03 SeaVoX Vertical Co-ordinate Coverages 2021-01-06 revision atmosphere Documents https://www.marinedataexchange.co.uk/details/TCE-4141/summary A link to the web service or dataset. download https://www.marinedataexchange.co.uk A link to the general host site. download series Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 publication ot evaluated This report uses data from Walney Extension Offshore Wind Farm to generate three offshore wind farm “scenarios” which were tested against an experimental marine version of Natural Englands Biodiversity Metric, to highlight some of the advantages and challenges of using a metric to calculate biodiversity value of marine environments, as well as some of the more general challenges of implementing Marine Net Gain policy. Two versions of this metric were tested within the report, with one metric including a “strategic significance” factor which increased the value of a habitat if it was located within an area of particular importance to biodiversity, for example a Marine Protected Area. An additional metric was used to calculate impact of a development on species.