Estimating the Economic Costs of Invasive Non-native Species (INNS) in Great Britain

Invasive non-native species (INNS) represent a significant and growing threat to ecosystems and ecosystem services in the GB. The arrival and establishment of these species can have severe adverse economic impacts on a wide range of sectors (e.g. agriculture, transport and utilities). As of 2019, there were 3,224 non-native species in Great Britain (GB), of which 2,010 were classified as established (reproducing in the wild) (Joint Nature Conservation Committee, 2020). Of these, 193 were considered to be invasive (i.e. exerting a negative impact on native biodiversity) with associated economic and financial costs. An estimated 10-12 new non-native species become established every year. (Department for Environment, Food and Rural Affairs, 2015) There remains a significant gap in our understanding of the size and nature of the economic impacts of INNS, and as such, a better framework of estimating the costs is needed to improve prioritise investment in prevention, intervention and management of INNS. A 2010 study on "The Economic Costs of Invasive Non-Native Species on Great Britain" (Williams, et al., 2010) compiled useful estimates of the costs of INNS on GB by focussing on financial control costs and market impacts of INNS, but this estimate is increasingly out of date. The 25-year Environment Plan (25 YEP) emphasizes the need for both a natural capital approach to valuing nature as a means of capturing non-market impacts and indirect costs, as well as the need for an effective strategy to dealing with INNS. A 2019 scoping study commissioned by the Department for Environment, Food and Rural Affairs (Defra) (Atkins, 2019) explored the feasibility of using a comprehensive natural capital approach to account for the full impacts of INNS including their impact on ecosystem services. To develop a fuller and more up-to-date assessment of the economic costs posed by INNS, we intend to take a two-phase approach: - The aims of this study (phase 1) would be to update the 2010 work, to quantify the current direct costs of INNS - A subsequent project (phase 2) will complement this and undertake detailed primary valuation work to assess the more difficult impacts to quantify, taking into account the work undertaken in Atkins 2019. Together these projects will ensure we have an up to date, more comprehensive understanding of the full costs of INNS in GB.