Number and cumulative number of marine non-indigenous species in Europe's seas, 1970-2021

The figure shows the number of new NIS (non-indigenous species) reported by marine region. The line-bar chart shows the total number of new introductions of NIS (grey bars) and by main species group (lines) reported in Europe’s seas combined and by marine region, per 6-year interval between 1970 and 2017. The stacked column charts show the cumulative number of new NIS introductions by main species group, in Europe’s seas combined and by marine region, per 6-year interval between 1970-2017 and for the period 2018-2021.

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Units

Number of new NIS and cumulative number of new NIS

Additional information

• Regional (and sub-regional) assessments do not add up to the pan-European assessment since the latter only considers species once. NIS registered in more than one regional sea are recorded in each. Additionally, partly native species are considered NIS in some regions/sub-regions but not at the pan-European level. See the table that provides results by subregion.
• The latest assessment cycle consists of only 4 years (2018-2021).
• Due to the time lapse between observation and publication, the rate of introduction for the most recent years (2020-2021), is an underestimate.

Methodology

National inventories of NIS were revised and updated with published data from biodiversity and hot-spot campaigns, academic surveys, and citizen science observed until December 2021. The revised list was validated with the contribution of national experts.
Microalgae and parasite/pathogen species identified are excluded.
Cryptogenic, questionable and range-expanding species identified are also excluded from all analyses.
Native, partly native species identified are excluded at EU level but included in sub-regional assessments for subregions where they have not been identified as native.

Marine non-indigenous species in Europe’s seas

Number and cumulative number of marine non-indigenous species in Europe's seas, 1970-2021

Related content

References and footnotes