Are the “100 of the world’s worst” invasive species also the costliest?

Biological invasions are increasing worldwide, damaging ecosystems and socioeconomic sectors. Two decades ago, the “100 of the world’s worst” invasive alien species list was established by the IUCN to improve communications , identifying particularly damaging ‘flagship’ invaders globally (hereafter, worst). Whilst this list has bolstered invader awareness, whether worst species are especially economically damaging and how they compare to other invaders (hereafter, other) remain unknown. Here, we quantify invasion costs using the most comprehensive global database compiling them (InvaCost). We compare these costs between worst and other species against sectorial, taxonomic and regional descriptors, and examine temporal cost trends. Only 60 of the 100 worst species had invasion costs considered as highly reliable and actually observed estimates (median: US$43 million). On average, these costs were significantly higher than the 463 other invasive species recorded in InvaCost (median: US$ 0.53 million), although some other species had higher costs than most worst species. Damages to the environment from the worst species dominated, whereas other species largely impacted agriculture. Disproportionately highest worst species costs were incurred in North America, whilst costs were more evenly distributed for other species; animal invasions were always costliest. Proportional management expenditures were low for the other species, and surprisingly, over twice as low for the worst species. Temporally, costs increased more for the worst than other taxa; however, management spending has remained very low for both groups. Nonetheless, since 40 species had no robust and/or reported costs, the “true” cost of “some of the world’s worst” 100 invasive species still remains unknown

Biological invasions as burdens to primary economic sectors

Many human-introduced alien species economically impact industries worldwide. Management prioritisation and coordination efforts towards biological invasions are hampered by a lack of comprehensive quantification of costs to key economic sectors. Here, we quantify and estimate global invasion costs to seven major sectors and unravel the introduction pathways of species causing these costs — focusing mainly on primary economic sectors: agriculture, fisheries and forestry. From 1970 to 2020, costs reported in the InvaCost database as pertaining to Agriculture, Fisheries, and Forestry totaled $509 bn,$1.3 bn, and $134 bn, respectively (in 2017 United States dollars). Pathways of costly species were diverse, arising predominantly from cultural and agricultural activities, through unintentional contaminants with trade, and often impacted different sectors than those for which species were initially introduced. Costs to Agriculture were pervasive and greatest in at least 37$365 bn), followed by China ($101 bn), and Australia ($36 bn). We further identified 19 countries highly economically reliant on Agriculture, Fisheries, and Forestry that are experiencing massive economic impacts from biological invasions, especially in the Global South. Based on an extrapolation to fill cost data gaps, we estimated total global costs ranging from at least $517–1,400 bn for Agriculture,$5.7–6.5 bn for Fisheries, and $142–768 bn for Forestry, evidencing substantial underreporting in the Forestry sector in particular. Burgeoning global invasion costs challenge sustainable development and highlight the need for improved management action to reduce future impacts on industry. Significance: With rapidly rising biological invasion rates, efficient management is critical for economic and environmental impact mitigation. Specifically, improved quantification of the economic cost of biological invasions to the world's primary economic sectors could provide crucial information for policymakers who must prioritise actions to limit ongoing and future impacts. We show that since 1970, over$600 bn in impacts has been incurred across Agriculture, Fisheries and Forestry, with the largest share reported in Agriculture. We further identify 19 countries, which rely heavily on primary sectors, facing comparatively high impacts from invasions, requiring urgent action. However, gaps in cost reporting across invasive taxa and countries suggest that these impacts are grossly underestimated. Proactive prioritisation by policymakers is needed to mitigate future impacts to primary sectors.</p

Economic costs of protecting islands from invasive alien species

Funding Information: This work was conducted following a workshop funded by the AXA Research Fund Chair of Invasion Biology and is part of the AlienScenario project funded by BiodivERsA‐Belmont Forum Project “Alien Scenarios” (BL: FWF project no. I 4011‐B32). The authors also acknowledge the French National Research Agency (ANR‐14‐CE02‐0021) and the BNP‐Paribas Foundation Climate Initiative for funding the InvaCost project and enabling the construction of the database, with particular thanks to C. Diagne. T.W.B. acknowledges funding from the European Union's Horizon 2020 research and innovation program Marie Skłodowska‐Curie fellowship (grant 747120). J.F.L. thanks the Auburn University School of Forestry and Wildlife Sciences for travel support to attend the InvaCost workshop. Funding for E.A. came from the AXA Research Fund Chair of Invasion Biology of the University of Paris Saclay. We also thank J. Albers and 2 anonymous reviewers and for their comments that strengthened this manuscript. Publisher Copyright: © 2022 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.Peer reviewedPublisher PD

Global economic costs of herpetofauna invasions

Biological invasions by amphibian and reptile species (i.e. herpetofauna) are numerous and widespread, having caused severe impacts on ecosystems, the economy and human health. However, there remains no synthesised assessment of the economic costs of these invasions. Therefore, using the most comprehensive database on the economic costs of invasive alien species worldwide (InvaCost), we analyse the costs caused by invasive alien herpetofauna according to taxonomic, geographic, sectoral and temporal dimensions, as well as the types of these costs. The cost of invasive herpetofauna totaled at 17.0 billion US$between 1986 and 2020, divided split into 6.3 billion US$ for amphibians, 10.4 billion US$for reptiles and 334 million US$ for mixed classes. However, these costs were associated predominantly with only two species (brown tree snake Boiga irregularis and American bullfrog Lithobates catesbeianus), with 10.3 and 6.0 billion US$ in costs, respectively. Costs for the remaining 19 reported species were relatively minor ( 99%), while for reptiles, impacts were reported mostly through damages to mixed sectors (65%). Geographically, Oceania and Pacific Islands recorded 63% of total costs, followed by Europe (35%) and North America (2%). Cost reports have generally increased over time but peaked between 2011 and 2015 for amphibians and 2006 to 2010 for reptiles. A greater effort in studying the costs of invasive herpetofauna is necessary for a more complete understanding of invasion impacts of these species. We emphasise the need for greater control and prevention policies concerning the spread of current and future invasive herpetofauna.info:eu-repo/semantics/publishedVersio

Knowledge gaps in economic costs of invasive alien fish worldwide

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Biological invasion costs reveal insufficient proactive management worldwide

Funding Information: The authors thank the French National Research Agency (ANR-14-CE02-0021) and the BNP-Paribas Foundation Climate Initiative for funding the InvaCost project and the work on InvaCost database development. The present work was conducted in the frame of InvaCost workshop carried in November 2019 (Paris, France) and funded by the AXA Research Fund Chair of Invasion Biology and is part of the AlienScenario project funded by BiodivERsA and Belmont-Forum call 2018 on biodiversity scenarios. RNC was funded through a Leverhulme Early Career Fellowship (ECF-2021-001) from the Leverhulme Trust and a Humboldt Postdoctoral Fellowship from the Alexander von Humboldt Foundation. DAA is funded by the Kuwait Foundation for the Advancement of Sciences (KFAS) (PR1914SM-01) and the Gulf University for Science and Technology (GUST) internal seed funds (187092 & 234597). CA was funded by the French National Centre for Scientific Research (CNRS). TWB acknowledges funding from the European Union's Horizon 2020 research and innovation programme Marie Skodowska-Curie fellowship (Grant No. 747120). FE was funded through the 2017?2018 Belmont Forum and BiodivERsA joint call for research proposals, under the BiodivScen ERA-Net COFUND programme, and with the funding organisation Austrian Science Foundation FWF (grant I 4011-B32). NK is funded by the basic project of Sukachev Institute of Forest SB RAS, Russia (Project No. 0287-2021-0011; data mining) and the Russian Science Foundation (project No. 21-16-00050; data analysis).Peer reviewedPublisher PD

Economic costs of biological invasions in the United Kingdom

Although the high costs of invasion are frequently cited and are a key motivation for environmental management and policy, synthesised data on invasion costs are scarce. Here, we quantify and examine the monetary costs of biological invasions in the United Kingdom (UK) using a global synthesis of reported invasion costs. Invasive alien species have cost the UK economy between US$6.9 billion and$17.6 billion (£5.4 – £13.7 billion) in reported losses and expenses since 1976. Most costs were reported for the entire UK or Great Britain (97%); country-scale cost reporting for the UK's four constituent countries was scarce. Reports of animal invasions were the costliest ($4.7 billion), then plant ($1.3 billion) and fungal ($206.7 million) invasions. Reported damage costs (i.e. excluding management costs) were higher in terrestrial ($4.8 billion) than aquatic or semi-aquatic environments ($29.8 million), and primarily impacted agriculture ($4.2 billion). Invaders with earlier introduction years accrued significantly higher total invasion costs. Invasion costs have been increasing rapidly since 1976, and have cost the UK economy $157.1 million (£122.1 million) per annum, on average. Published information on specific economic costs included only 42 of 520 invaders reported in the UK and was generally available only for the most intensively studied taxa, with just four species contributing 90% of species-specific costs. Given that many of the invasive species lacking cost data are actively managed and have well-recognised impacts, this suggests that cost information is incomplete and that totals presented here are vast underestimates owing to knowledge gaps. Financial expenditure on managing invasions is a fraction (37%) of the costs incurred through damage from invaders; greater investments in UK invasive species research and management are, therefore, urgently required

What will the future bring for biological invasions on islands? an expert-based assessment

Biological invasions are a major threat to global biodiversity with particularly strong implications for island biodiversity. Much research has been dedicated towards understanding historic and current changes in alien species distribution and impacts on islands and potential changes under future climate change. However, projections of how alien species richness and impacts on islands might develop in the future are still lacking. In the absence of reliable projections, expert-based assessments are a valuable tool to investigate the importance of different drivers and pathways and the distributions of potential impacts of future biological invasions. These insights can guide subsequent quantification efforts and inform invasive species management and policy. In this study, we performed a survey among 126 experts in invasion science ranging from scientists to managers and decision makers with a focus on island systems until the mid-21st century. The survey revealed that out of 15 drivers, six were considered important by almost all respondents (>90%). Of these, trade and transport was identified as most important at the introduction stage (99.2%) and land use/cover change as most important at the establishment (96.8%) and spread (95.2%) stage. Additionally, the experts considered that alien species were more likely to be introduced (93.7%) and spread (78.6%) as stowaways than through any other pathway. In general, respondents agreed that the impacts of alien species will increase on all types of islands, particularly on oceanic islands, followed by atolls and continental islands. Within islands, terrestrial ecosystems were assumed to be impacted more severely than marine ecosystems. Finally, the survey hints toward the potential for effective communication, scientific research and increased pro-active management of alien species on islands to reduce their future consequences. Given the major threat represented by invasive alien species on islands, these results provide crucial insights relevant for global and regional conservation efforts.info:eu-repo/semantics/publishedVersio

Capacity of countries to reduce biological invasions

The extent and impacts of biological invasions on biodiversity are largely shaped by an array of socio-economic and environmental factors, which exhibit high variation among countries. Yet, a global analysis of how these factors vary across countries is currently lacking. Here, we investigate how five broad, country-specific socio-economic and environmental indices (Governance, Trade, Environmental Performance, Lifestyle and Education, Innovation) explain country-level (1) established alien species (EAS) richness of eight taxonomic groups, and (2) proactive or reactive capacity to prevent and manage biological invasions and their impacts. These indices underpin many aspects of the invasion process, including the introduction, establishment, spread and management of alien species. They are also general enough to enable a global comparison across countries, and are therefore essential for defining future scenarios for biological invasions. Models including Trade, Governance, Lifestyle and Education, or a combination of these, best explained EAS richness across taxonomic groups and national proactive or reactive capacity. Historical (1996 or averaged over 1996–2015) levels of Governance and Trade better explained both EAS richness and the capacity of countries to manage invasions than more recent (2015) levels, revealing a historical legacy with important implications for the future of biological invasions. Using Governance and Trade to define a two-dimensional socio-economic space in which the position of a country captures its capacity to address issues of biological invasions, we identified four main clusters of countries in 2015. Most countries had an increase in Trade over the past 25 years, but trajectories were more geographically heterogeneous for Governance. Declines in levels of Governance are concerning as they may be responsible for larger levels of invasions in the future. By identifying the factors influencing EAS richness and the regions most susceptible to changes in these factors, our results provide novel insights to integrate biological invasions into scenarios of biodiversity change to better inform decision-making for policy and the management of biological invasions

Damage costs from invasive species exceed management expenditure in nations experiencing lower economic activity

Financial disclosure The InvaCost project was funded by the French National Research Agency (ANR-14-CE02-0021), the BNP-Paribas Foundation Climate Initiative, the AXA Research Fund Chair of Invasion Biology of University Paris Saclay and by the BiodivERsA and Belmont-Forum call 2018 on biodiversity scenarios (AlienScenarios; BMBF/PT DLR 01LC1807C). M.K. received funding from the European Union's Horizon 2020 research programme under a Marie Skłodowska-Curie grant agreement 899546. C.J.A.B. acknowledges the Australian Research Council (CE170100015) for support. A.B. acknowledges Azim Premji University's grants programme (UNIV-RC00326) for support.Peer reviewe