Non-indigenous species spatial spread in UK waters from 1890 to 2020

Data are spatial occurrence records of thirteen Non-indigenous species (NIS) (Bonnemaisonia hamifera, Caprella mutica, Crepidula fornicate, Diadumene lineata, Ensis leei, Ficopomatus enigmaticus, Grateloupia turuturu, Magallana gigas, Sargassum muticum, Solidobalanus fallax, Styela clava, Undaria pinnatifida, Urosalpinx cinerea) subject to analysis under the UK Marine Strategy Indicator Assessment 2024 for the UK indicator 'The number of new populations of established invasive NIS'. Occurrence records from 2003 to 2020 collected in UK waters were combined with baseline data including records as far back as 1890.

NIS occurrence records for time period 2003-2020 inclusive were sought from NBN Atlas, Marine Recorder and Experts within the Devolved Administrations. These data were combined with baseline data including records as far back as 1890. Incomplete records (data rows where species name, year and/or longitude or latitude were missing) and duplicate records (data rows where species name, year and longitude and latitude combinations were not unique) were removed. Occurrence records were spatially joined to the 10km assessment grid, and coastal or transitional waters (according to the Water Framework Directive boundaries). Occurrence records within transitional waters and/or outside the 10km assessment grid were removed leaving only those records which fell within the UK Marine Strategy Assessment area.