Review Article |
Corresponding author: Liliana Ballesteros-Mejia ( ballesteros.liliana@gmail.com ) Academic editor: Franz Essl
© 2021 Liliana Ballesteros-Mejia, Elena Angulo, Christophe Diagne, Brian Cooke, Martin A. Nuñez, Franck Courchamp.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Ballesteros-Mejia L, Angulo E, Diagne C, Cooke B, Nuñez MA, Courchamp F (2021) Economic costs of biological invasions in Ecuador: the importance of the Galapagos Islands. In: Zenni RD, McDermott S, García-Berthou E, Essl F (Eds) The economic costs of biological invasions around the world. NeoBiota 67: 375-400. https://doi.org/10.3897/neobiota.67.59116
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Biological invasions, as a result of human intervention through trade and mobility, are the second biggest cause of biodiversity loss. The impacts of invasive alien species (IAS) on the environment are well known, however, economic impacts are poorly estimated, especially in mega-diverse countries where both economic and ecological consequences of these effects can be catastrophic. Ecuador, one of the smallest mega-diverse countries, lacks a comprehensive description of the economic costs of IAS within its territory. Here, using "InvaCost", a public database that compiles all recorded monetary costs associated with IAS from English and Non-English sources, we investigated the economic costs of biological invasions. We found that between 1983 and 2017, the reported costs associated with biological invasions ranged between US$86.17 million (when considering only the most robust data) and US$626 million (when including all cost data) belonging to 37 species and 27 genera. Furthermore, 99% of the recorded cost entries were from the Galapagos Islands. From only robust data, the costliest identified taxonomic group was feral goats (Capra hircus; US$20 million), followed by Aedes mosquitoes (US$2.14 million) while organisms like plant species from the genus Rubus, a parasitic fly (Philornis downsi), black rats (Rattus rattus) and terrestrial gastropods (Achatina fulica) represented less than US$2 million each. Costs of "mixed-taxa" (i.e. plants and animals) represented the highest (61% of total robust costs; US$52.44 million). The most impacted activity sector was the national park authorities, which spent about US$84 million. Results from robust data also revealed that management expenditures were the major type of costs recorded in the Galapagos Islands; however, costs reported for medical losses related to Aedes mosquitoes causing dengue fever in mainland Ecuador would have ranked first if more detailed information had allowed us to categorize them as robust data. Over 70% of the IAS reported for Ecuador did not have reported costs. These results suggest that costs reported here are a massive underestimate of the actual economic toll of invasions in the country.
Costos económicos de las invasiones biológicas en Ecuador: La importancia de las islas Galápagos. Las invasiones biológicas, al ser resultado de la intervención humana a través del comercio y la movilidad, son la segunda causa más importante de pérdida de biodiversidad. Los impactos de las especies exóticas invasoras (EEI) en el medio ambiente son bien conocidos, sin embargo, los impactos económicos aún son poco estimados, especialmente en países megadiversos donde las consecuencias económicas y ecológicas de estos efectos pueden ser catastróficas. Ecuador, uno de los países megadiversos más pequeños, carece de una descripción completa de los costos económicos de las EEI dentro de su territorio. En este estudio, investigamos los costos de las investigaciones biológicas, utilizando "InvaCost", una base de datos pública que compila todos los costos monetarios registrados asociados con las EEI de fuentes tanto en inglés como en español. Encontramos que entre 1983 y 2017, los costos reportados asociados con las invasiones biológicas oscilaron entre US$86,17 millones (considerando sólo los datos más robustos) y US$626 millones (incluyendo todos los datos de costos) pertenecientes a 37 especies y 27 géneros. Además, el 99% de los costos registrados fueron en las Islas Galápagos. Al utilizar sólo datos robustos, el grupo taxonómico identificado más costoso fueron las cabras salvajes (Capra hircus; US$20 millones), seguido de los mosquitos Aedes (US$2,14 millones), mientras que organismos como especies de plantas del género Rubus, la mosca parásita (Philornis downsi), las ratas negras (Rattus rattus) y los gasterópodos terrestres (Achatina fulica) representaron menos de 2 millones de dólares cada uno. Los costos de los taxones mixtos (es decir, plantas y animales) representaron los más altos (61% de los costos robustos totales; US$52,44 millones). El sector de actividad más afectado fue el de las autoridades del parque nacional, que gastó alrededor de 84 millones de dólares. Los resultados de datos robustos también revelaron que los gastos de gestión fueron el principal tipo de costos registrados en las Islas Galápagos; sin embargo, los costos reportados por pérdidas médicas relacionadas con los mosquitos Aedes que causan la fiebre del dengue en el Ecuador se habrían clasificado en primer lugar, si la existencia de información más detallada nos hubiera permitido clasificarlos como datos robustos. Más del 70% de las EEI conocidas para Ecuador no tuvieron costos reportados. Estos resultados sugieren que los costos aquí discutidos son una subestimación masiva del costo económico real de las invasiones en el país.
Custos econômicos das invasões biológicas no Equador: importância das Ilhas Galápagos. As invasões biológicas, como resultado da intervenção humana por meio do comércio e da mobilidade, são a segunda maior causa da perda de biodiversidade. Os impactos das espécies exóticas invasoras (EEI) no meio ambiente são bem conhecidos. No entanto, os impactos econômicos ainda nem tanto, especialmente em países megadiversos onde as consequências econômicas e ecológicas desses efeitos podem ser catastróficas. O Equador, um dos menores países megadiversos, carece de uma descrição abrangente dos custos econômicos das EEI em seu território. Neste estudo, usando o "InvaCost", um banco de dados público que compila todos os custos monetários associados às EEI de fontes em inglês e espanhol, investigamos os custos econômicos das invasões biológicas. Descobrimos que, entre 1983 e 2017, os custos relatados associados às invasões biológicas variaram entre US$86,17 milhões (considerando apenas os dados mais robustos) e US$626 milhões (incluindo todos os dados) pertencentes a 37 espécies e 27 gêneros. Além disso, 99% das entradas de custos registradas eram das Ilhas Galápagos. Apenas com dados robustos, o grupo taxonômico mais custoso identificado foi de cabras selvagens (Capra hircus; US$20 milhões), seguido por mosquitos Aedes (US$2,14 milhões). Por outro lado, organismos como espécies de plantas do gênero Rubus, uma mosca parasita (Philornis downsi), o rato-preto (Rattus rattus) e os gastrópodes terrestres (Achatina fulica) representaram menos de US$ 2 milhões cada. Os custos dos táxons mistos (ou seja, plantas e animais) representaram os mais altos (61% dos custos robustos totais; US$52,44 milhões). O setor de atividade mais impactado por esses custos foram as autoridades do parque nacional, que gastaram cerca de US$84 milhões. Os resultados de dados robustos também revelaram que as despesas de gerenciamento foram o principal tipo de custo registrado nas Ilhas Galápagos. No entanto, os custos registrados de perdas médicas relacionadas aos mosquitos Aedes, que causam a dengue no Equador, teriam ficado em primeiro lugar, se tivéssemos informações mais detalhadas que nos permitiram classificá-los como dados robustos. Mais de 70% das espécies invasoras não apresentam custos para o Equador. Esses resultados sugerem que os custos relatados, neste trabalho, estão subestimados quanto ao custo real das invasões no país.
Coûts économiques des invasions biologiques en Équateur : l’importance des îles Galapagos. Les invasions biologiques, résultant de l’intervention humaine par le commerce et la mobilité internationaux, sont la deuxième cause de perte de biodiversité. Les impacts des espèces exotiques envahissantes (EEE) sur l’environnement sont bien connus, mais les impacts économiques sont mal estimés, en particulier dans les pays à biodiversité méga-diverse où les conséquences économiques et écologiques de ces effets peuvent être catastrophiques. L’Équateur, l’un des plus petits pays méga-divers, ne bénéficie toujours pas de description complète des coûts économiques des espèces exotiques envahissantes pour son territoire. Ici, nous avons étudié les coûts économiques des invasions biologiques en utilisant "InvaCost", une base de données publique qui compile tous les coûts monétaires associés a ces invasions, provenant de sources en langues anglaise et non-anglaise. Nous avons constaté qu’entre 1983 et 2017, les coûts déclarés associés aux invasions biologiques variaient entre 86,17 millions de dollars américains (si l’on considère uniquement les données les plus robustes) et 626 millions de dollars américains (si l’on inclut toutes les données disponibles), appartenant à 37 espèces et 27 genres. De plus, 99 % des entrées de coûts enregistrées pour l’Équateur provenaient des îles Galápagos. D’après les données les plus robustes, le groupe taxonomique le plus coûteux est celui des chèvres sauvages (Capra hircus; 20 millions de dollars), suivi des moustiques du genre Aedes (2,14 millions de dollars), tandis que des organismes comme des espèces végétales du genre Rubus, des mouches parasites (Philornis downsi), les rats noirs (Rattus rattus). et des gastéropodes terrestres (Achatina fulica) représentaient moins de 2 millions de dollars US chacun. Les coûts des taxons mixtes (c.-à-d. plantes et animaux indifférenciés) sont les plus élevés (61 % des coûts robustes totaux, soit 52,44 millions de dollars américains). Le secteur d’activité le plus impacté est représenté par les autorités des parcs nationaux, qui ont dépensé environ 84 millions de dollars. Les données les plus robustes ont également révélé que les dépenses de gestion constituaient le principal type de coûts enregistrés dans les îles Galápagos; toutefois, les coûts déclarés pour les pertes médicales liées aux moustiques Aedes causant la dengue en Équateur continental auraient été classés au premier rang si des informations plus détaillées nous avaient permis de les catégoriser comme des données robustes. Plus de 70 % des EEE recencées en Équateur n’ont pas de coûts déclarés. Ces résultats suggèrent que les coûts rapportés ici sont une sous-estimation massive du fardeau économique réel des invasions biologiques dans le pays.
Wirtschaftliche Kosten biologischer Invasionen in Ecuador: die Bedeutung der Galapagos-Inseln. Biologische Invasionen infolge menschlicher Eingriffe durch Handel und Mobilität sind die zweitgrößte Ursache für den Verlust der biologischen Vielfalt. Die Auswirkungen invasiver gebietsfremder Arten (IAS) auf die Umwelt sind allgemein bekannt. Die wirtschaftlichen Auswirkungen werden jedoch nur unzureichend geschätzt, insbesondere in Ländern mit großer Vielfalt, in denen die wirtschaftlichen und ökologischen Folgen dieser Auswirkungen katastrophal sein können. In Ecuador, einem der kleinsten Länder mit großer Vielfalt, fehlt eine umfassende Beschreibung der wirtschaftlichen Kosten von IAS in seinem Hoheitsgebiet. Hier haben wir mithilfe von "InvaCost", einer öffentlichen Datenbank, die alle mit IAS verbundenen monetären Kosten aus englischen und nicht englischen Quellen zusammenstellt, die wirtschaftlichen Kosten biologischer Invasionen untersucht. Wir haben festgestellt, dass zwischen 1983 und 2017 die mit biologischen Invasionen verbundenen Kosten zwischen 86,17 Mio. USD (unter Berücksichtigung nur der robustesten Daten) und 626 Mio. USD (unter Einbeziehung aller Kostendaten) zu 37 Arten und 27 Gattungen lagen. Darüber hinaus stammten 99% der erfassten Kosteneinträge von den Galapagos-Inseln. Aus nur belastbaren Daten ging hervor, dass Wildziegen (Capra hircus; 20 Mio. USD) die teuerste taxonomische Gruppe waren, gefolgt von Aedes-Mücken (2,14 Mio. USD). Jedoch, Organismen wie Pflanzenarten der Gattung Rubus, einer parasitären Fliege (Philornis downsi), schwarze Ratten (Rattus rattus) und terrestrische Gastropoden (Achatina fulica) machten jeweils weniger als 2 Millionen US-Dollar aus. Die Kosten für gemischte Taxa (d. H. Pflanzen und Tiere) waren am höchsten (61% der gesamten robusten Kosten; 52,44 Mio. USD). Der am stärksten betroffene Aktivitätssektor waren die Nationalparkbehörden, die rund 84 Millionen US-Dollar ausgaben. Die Ergebnisse robuster Daten zeigten auch, dass die Verwaltungsausgaben die Hauptkosten auf den Galapagos-Inseln waren. Die Kosten für medizinische Verluste im Zusammenhang mit Aedes-Mücken, die auf dem ecuadorianischen Festland Dengue-Fieber verursachen, wären jedoch an erster Stelle gestanden, wenn wir durch detailliertere Informationen als robuste Daten eingestuft werden könnten. Über 70% der für Ecuador gemeldeten IAS hatten keine Kosten gemeldet. Diese Ergebnisse deuten darauf hin, dass die hier gemeldeten Kosten die tatsächliche wirtschaftliche Belastung durch Invasionen im Land massiv unterschätzen.
Damages, economic costs, InvaCost, invasive alien species, mainland Ecuador, management
Invasive alien species (IAS) are defined as non-native species that, as a result of human transportation or trade, establish in a new ecosystem where they may cause environmental impact, economic harm or affect human health (
Invasive alien species are also responsible for a variety of substantial losses across many socio-economic sectors (
Ecuador, one of the smallest of the world’s 17 mega-diverse countries, harbors unique ecosystems as well as an extraordinary number of endemic species (
The Galapagos Islands have been invaded by many species from a variety of taxa representing an exceptional threat to this vulnerable insular ecosystem. Up to 2017, the number of alien terrestrial and marine species recorded in the islands was 1,522 (
In addition, there are 545 species of introduced insects and 77 other terrestrial invertebrates (
Invasive species also have impacts on mainland Ecuador. For example, in the public health system, Aedes mosquitoes are a medically important vector of arboviral diseases, such as dengue fever and chikungunya in the whole country and throughout Latin America. Control of the Aedes species remains the principal means of preventing and managing outbreaks but it requires considerable investment of time and resources. People living on the urban periphery are particularly vulnerable and are in need of public health management strategies that integrate local, policy-relevant research that guides the design, implementation and evaluation of dengue management (
So far, there has been no national assessment of all the economic costs incurred by IAS in Ecuador, although such cost assessments are of strong interest for both research and management purposes (Dana et al. 2013;
We extracted costs data associated with IAS from the "InvaCost" database (Invacost 3.0;
From this data assembly we selected cost entries specific to the country of Ecuador (column “Official_country”), resulting in 153 entries (herein, "raw data"; Data are provided in the Suppl. material
We annualized all "raw data" entries (except six entries due to lack of precise information about the duration of the costs) to consider the temporal frame in which they occurred. This was necessary because the duration of reported costs is very heterogeneous, varying from few months to several years. To estimate annual costs of invasions, our cost entries were expanded along the number of years during which each cost occurred. For this purpose, we used the "expandedYearlyCosts" function of the "invacost" R package (
From the resulting expanded database and the year in which the costs occurred, we calculated the cumulative and average costs of invasive species in Ecuador for the period 1983 to 2017, using the function "summarizeCosts" from the same "invacost" R package. We analyzed and provided average costs in five-year intervals over the above-targeted period.
Once all the data were annualized, we filtered the data using two important descriptors of the costs: the reliability of the cost estimate and the implementation of the cost (columns “Method_Reliability”, and “Implementation” respectively of the database, Suppl. material
Invasion costs estimates were analyzed based on three descriptors:
Taking into account only the "robust data" (i.e. "observed" and "highly reliable" cost data), the total economic costs of biological invasions in Ecuador amounted to US$86.17 million from 1983 to 2017 (n = 317, Fig.
Distribution of economic costs (outer circles US$ million) and number of entries (inner circles) of invasive species in Ecuador according to: (a) level of reliability of the cost entries (High and Low); (b) implementation of the cost reported (Observed and Potential). "Robust data" is the combination of highly reliable entries and observed implementation, whereas "Non-robust" data is otherwise.
Temporal trend of the total costs in 2017-equivalent US dollars incurred by invasive species in Ecuador over time. Only robust data is represented (i.e. both observed and highly reliable). Each point represents the cumulative cost for a given year whereas its size is proportional to the number of estimates for that particular year. Average annual costs are calculated in 5-year periods and are represented by dots and horizontal solid lines. Dashed lines connect the average annual costs for these 5-year periods.
The costs entries of Ecuador came almost exclusively from the Galapagos Islands (99%, corresponding to US$86.17 million, n = 315 entries, Fig.
Maps of the economic costs of invasive species in Ecuador: Only robust data is represented (i.e. observed and highly reliable). Values are reported for islands and mainland Ecuador. Bubble size represents the amount of costs in US$ millions grouped by similar colors. Dashed lines denote the costs reported for the entire archipelago.
Expenditures on "Management" constituted the large majority of the type of economic costs reported for Ecuador, with US$86.06 million (99.8%; n = 314 entries) involving control, eradication, monitoring and administrative management actions. The remaining 0.2% of the costs are divided between economic costs due to "Damage" of US$0.01 million (n = 1 entry) and "unspecified" costs amounting to US$0.107 million (referring to indirect costs; n = 2 entries). When including "non-robust data", damage losses, are all associated with medical care (US$525.9 million; eight entries, Suppl. material
The most impacted activity sector was "Authorities-stakeholders" (i.e. those governmental services or organizations allocating efforts and resources for managing invasive species,
Total economic management costs per impacted activity sector taking into account only robust data (i.e. observed and highly reliable).
Impacted sector | Total cost US$ million | Number entries |
---|---|---|
Authorities-Stakeholders | 84.03 | 309 |
Mixed | 2.14 | 7 |
Agriculture | 0.001 | 1 |
Regarding taxonomy, the highest economic costs were reported for "mixed-taxa" (61.4%; US$52.44 million, n = 12 entries, Fig.
The ten costliest genus in Ecuador. IAS represents costs for multiple species. Costs are reported in million US dollars.
Management actions on "mixed-taxa" of invasive species have fallen most heavily upon governmental organisms such as the Galapagos National Park Directorate and/or other institutions such as the Charles Darwin Foundation, incurring expenditures of US$52.44 million (n = 12 entries; Suppl. material
Our findings showed that biological invasions cost the Ecuadorian economy at least US$86.17 million between 1983 and 2017, and that most of these expenses were reported between 2007–2009 (Fig.
The World Heritage status and the history of Charles Darwin formulating his theory of evolution after visiting Galapagos, promoted the Galapagos Islands to a flagship conservation area that helps attract major resources for both research and conservation. It has led to the establishment of institutions like the Charles Darwin Foundation and its Research Station that attracts researchers from all around the world and in turn has promoted the transfer of ideas and expertise (in both directions, local and international institutions and individuals). This has also enabled the securing of substantial amounts of funding for conservation. For example, the funding of a multi-partner 6-year program (US$43 million) for managing invasive species (
At the same time, the status as a protected area and a World Heritage site makes the Galapagos Islands an important hub for ecotourism that now underpins the national economy. Tourism has grown from 1,000 tourists per year in 1960 up to >270,000 tourists in 2019 (
Quality control in databases is crucial for ensuring accurate assessments and conclusions, particularly in invasion science, where results are used to inform conservation managers, practitioners and environmental policy makers. We chose to use a highly conservative and robust dataset to draw our conclusions, and then delineated the pitfalls in our interpretation of the cost distribution. We are aware that our decisions to include or exclude some data might have consequences on our quantitative conclusions. For example, Aedes mosquitoes occupied third place in our list of the costliest species in Ecuador because we excluded its data from the most robust dataset; yet this species complex ranks much higher in economic costs assessments for other South American countries (such as Argentina,
The leading type of costs reported across the assembled dataset was expenditure in management. This is in contrast to results from the analysis of "InvaCost" data in other regions, where damage costs far outweighed management investments, for example, in Asia (
We found robust costs for only 36 invasive species, whereas the Global Invasive species database reports 125 species known to be invasive in Ecuador (GISD,
This study is the first attempt to construct an economic assessment of biological invasions of Ecuador, by standardizing and compiling available information from both English and Spanish sources. Our results show a disproportionate lack of investment in mainland Ecuador compared to the Galapagos Islands. However, the lack of accessible published data limits our effective assessment of the economic costs of biological invasion in the whole territory. Despite our efforts to find more information, there is still a need to investigate other sources of information (e.g. internal reports, theses, conference proceedings and the grey literature in general) to gain a more comprehensive overview. In turn, assessments of economic impacts of invasive species might benefit from having reports and projects published more accessible to the public.
Contrary to other countries in the region – whether mega-diverse or not (
The authors acknowledge the French National Research Agency (ANR-14-CE02-0021) and the BNP-Paribas Foundation Climate Initiative for funding the Invacost project that allowed the construction of the InvaCost database. The present 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 and Belmont-Forum call 2018 on biodiversity scenarios. Thanks to Melissa Ballesteros for helping with the abstract translations. EA and LBM contracts come from the AXA Research Fund Chair of Invasion Biology of University Paris Saclay. CD is funded by the BiodivERsA-Belmont Forum Project “Alien Scenarios” (BMBF/PT DLR 01LC1807C). The authors also thank Virginia Duboscq-Carra for her contribution of compiling data for "InvaCost". We want to acknowledge all environmental managers, and researchers who kindly answered our request for information about the costs of invasive species. Last but not least, the authors thank Dr. Heinke Jäger for her thorough revision of the article which greatly improved it.
Database of Economic costs of biological invasions in Ecuador
Data type: database
Explanation note: Dataset on costs of invasive species in Ecuador extracted from InvaCost database (Diagne et al 2020) and descriptions of the column names.
Tables S2–S5
Data type: tables
Explanation note: Table S2. Economic costs (only robust data; US$ million) discriminated per genus, impacted sector and type of cost in Ecuador. Impacted sectors are: Authorities-stakeholders (Auth-stak), Mixed (combination of two or more) and Agriculture. Costs are sorted in decreasing order per sector. Table S3. Economic costs (only non-robust data; US$ million) discriminated per genus, impacted sector and type of cost in Ecuador. Impacted sectors are: Authorities-stakeholders, Mixed (combination of two or more sectors). Costs are sorted by alphabetic order of the genus. Table S4. Economic costs (only robust data; US$ million) and number of cost entries of all the invasive species reported for Ecuador grouped by genus and ordered decreasingly from the costliest to the less costly. Table S5. Economic costs (only non-robust data; US$ million) and number of cost entries of all the invasive species reported for Ecuador grouped by genus and ordered decreasingly from the costliest to the less costly. Note that genus Felis is the only genus that does not report entries considered robust data.