H1: Abatement of the number of invasive non-native species entering and establishing against a baseline
Short Description
Biosecurity measures to prevent the establishment of invasive non-native species are a key element of protecting against their significant economic, environmental and social impacts. This indicator will show how the number of invasive non-native species entering Great Britain has been abated (reduced) by comparing a predicted trend for establishment of invasive non-native species against actual establishment. Establishment of invasive species depends on factors such as trade and climate change. The difference to the trend in actual establishment then provides a measure of the success of biosecurity measures.
The indicator will draw on data from the Non-Native Species Information Portal, overseen by the ‘Great Britain Non-Native Species Secretariat’, which maintains an early detection, surveillance and monitoring mechanism that facilitates management, including rapid response. This indicator requires significant development, including deciding on which species to include and establishing a baseline for the predicted and established trend.
Readiness and links to data
This indicator is not available for reporting in 2024 in a finalised form. An interim indicator is presented here that shows trends in the number of established non-native species in Great Britain. These data are published annually as UK Biodiversity Indicator B6 – Pressure from invasive species.
There are 3,343 non-native species in Great Britain, 2,074 of which are classified as established (reproducing in the wild). The B6 indicator contains 195 non-native species (48 freshwater, 39 marine and 108 terrestrial) that are considered to be exerting a negative impact on native biodiversity and are therefore termed invasive. In total, 104 of these invasive non-native species (14 freshwater, 29 marine and 61 terrestrial) are established across or along 10% or more of the land area or coastline of Great Britain and are hence included in this interim indicator. Further development is required to compare these data against a predicted trend.
New exploratory work is ongoing to consider the future finalisation of this indicator in terms of both scope and methodological design.
Indicator components
Figure H1: Cumulative net total number of invasive non-native species established across or along 10% or more of the land area or coastline of Great Britain, 1969 to 2022
Table H1: Cumulative net total number of invasive non-native species established across or along 10% or more of the land area or coastline of Great Britain, 1969 to 2022
| Year | Freshwater | Marine (Coastal) | Terrestrial |
|---|---|---|---|
| 1969 | 4 | 2 | 28 |
| 1979 | 6 | 5 | 37 |
| 1989 | 11 | 11 | 45 |
| 1999 | 12 | 14 | 51 |
| 2009 | 12 | 24 | 57 |
| 2019 | 13 | 29 | 60 |
| 2022 | 14 | 29 | 61 |
Trend description for H1
Between 1969 and 2022, the number of invasive non-native species established in or along 10% or more of Great Britain’s land area or coastline has increased in the freshwater, terrestrial and marine (coastal) environments, with the greatest increases in numbers having been observed in the marine and terrestrial environments (27 and 33 species respectively).
Assessment of change
The H1 indicator ‘Abatement of the number of invasive non-native species entering and establishing against a baseline’ reports one cumulative net total data point for each 10-year period included within the indicator, unlike the majority of other indicators that report annually. Therefore, it is only possible to assess long-term trends as there are insufficient data points to establish trends over the medium and short-term time periods, or since 2018. An increase (deterioration) was observed over the long term for freshwater, marine and terrestrial invasive non-native species.
Further information on this assessment, along with details on the methodology, is provided in the Assessment background page. Summaries by 25 Year Environment Plan goal and information on indicator links are presented in the Assessment results pages.
Table H1: Assessment of change
| Component | Subcomponent | Period | Date range | Percentage change | Smoothing function | Assessment of change |
|---|---|---|---|---|---|---|
| H1 | Freshwater | Short term | N/A | N/A | N/A | Not assessed |
| H1 | Freshwater | Medium term | N/A | N/A | N/A | Not assessed |
| H1 | Freshwater | Long term | 1969 to 2022 | 250.00 | Unsmoothed | Deterioration |
| H1 | Marine (Coastal) | Short term | N/A | N/A | N/A | Not assessed |
| H1 | Marine (Coastal) | Medium term | N/A | N/A | N/A | Not assessed |
| H1 | Marine (Coastal) | Long term | 1969 to 2022 | 1,350.00 | Unsmoothed | Deterioration |
| H1 | Terrestrial | Short term | N/A | N/A | N/A | Not assessed |
| H1 | Terrestrial | Medium term | N/A | N/A | N/A | Not assessed |
| H1 | Terrestrial | Long term | 1969 to 2022 | 117.86 | Unsmoothed | Deterioration |
Note that each data point reported for this indicator represents the cumulative net total at that point in time rather than annual data. Percentage change in Table H1 refers to the difference seen between the first and last year in the specified date range.