Research Article |
Corresponding author: Jose M. Zamora-Marín ( josemanuel.zamora@um.es ) Corresponding author: Francisco J. Oliva-Paterna ( fjoliva@um.es ) Academic editor: Jaimie T.A. Dick
© 2023 Jose M. Zamora-Marín, Ana Ruiz-Navarro, Francisco J. Oficialdegui, Pedro M. Anastácio, Rafael Miranda, Pablo García-Murillo, Fernando Cobo, Filipe Ribeiro, Belinda Gallardo, Emili García-Berthou, Dani Boix, Leopoldo Medina, Felipe Morcillo, Javier Oscoz, Antonio Guillén, Antonio A. Herrero-Reyes, Francisca C. Aguiar, David Almeida, Andrés Arias, César Ayres, Filipe Banha, Sandra Barca, Idoia Biurrun, M. Pilar Cabezas, Sara Calero, Juan A. Campos, Laura Capdevila-Argüelles, César Capinha, André Carapeto, Frederic Casals, Paula Chainho, Santos Cirujano, Miguel Clavero, Jose A. Cuesta, Vicente Deltoro, João Encarnação, Carlos Fernández-Delgado, Javier Franco, Antonio J. García-Meseguer, Simone Guareschi, Adrián Guerrero-Gómez, Virgilio Hermoso, Celia López-Cañizares, Joaquín López-Soriano, Annie Machordom, Joana Martelo, Andrés Mellado-Díaz, Juan C. Moreno, Rosa Olivo del Amo, J. Carlos Otero, Anabel Perdices, Quim Pou-Rovira, Sergio Quiñonero-Salgado, Argantonio Rodríguez-Merino, Macarena Ros, Enrique Sánchez-Gullón, Marta I. Sánchez, David Sánchez-Fernández, Jorge R. Sánchez-González, Oscar Soriano, M. Alexandra Teodósio, Mar Torralva, Rufino Vieira-Lanero, Antonio Zamora-López, Francisco J. Oliva-Paterna.
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Citation:
Zamora-Marín JM, Ruiz-Navarro A, Oficialdegui FJ, Anastácio PM, Miranda R, García-Murillo P, Cobo F, Ribeiro F, Gallardo B, García-Berthou E, Boix D, Medina L, Morcillo F, Oscoz J, Guillén A, Herrero-Reyes AA, Aguiar FC, Almeida D, Arias A, Ayres C, Banha F, Barca S, Biurrun I, Cabezas MP, Calero S, Campos JA, Capdevila-Argüelles L, Capinha C, Carapeto A, Casals F, Chainho P, Cirujano S, Clavero M, Cuesta JA, Deltoro V, Encarnação J, Fernández-Delgado C, Franco J, García-Meseguer AJ, Guareschi S, Guerrero-Gómez A, Hermoso V, López-Cañizares C, López-Soriano J, Machordom A, Martelo J, Mellado-Díaz A, Moreno JC, Olivo del Amo R, Otero JC, Perdices A, Pou-Rovira Q, Quiñonero-Salgado S, Rodríguez-Merino A, Ros M, Sánchez-Gullón E, Sánchez MI, Sánchez-Fernández D, Sánchez-González JR, Soriano O, Teodósio MA, Torralva M, Vieira-Lanero R, Zamora-López A, Oliva-Paterna FJ (2023) A multi-taxa assessment of aquatic non-indigenous species introduced into Iberian freshwater and transitional waters. NeoBiota 89: 17-44. https://doi.org/10.3897/neobiota.89.105994
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Aquatic ecosystems are particularly vulnerable to the introduction of non-indigenous species (NIS), leading to multi-faceted ecological, economic and health impacts worldwide. The Iberian Peninsula comprises an exceptionally biodiverse Mediterranean region with a high number of threatened and endemic aquatic species, most of them strongly impacted by biological invasions. Following a structured approach that combines a systematic review of available information and expert opinion, we provide a comprehensive and updated multi-taxa inventory of aquatic NIS (fungi, macroalgae, vascular plants, invertebrates and vertebrates) in Iberian inland waters. Moreover, we assess overall patterns in the establishment status, introduction pathways, native range and temporal introduction trends of listed NIS. In addition, we discuss the legal coverage provided by both national (Spanish and Portuguese) and European NIS regulations. We inventoried 326 aquatic NIS in Iberian inland waters, including 215 established, 96 with uncertain establishment status and 15 cryptogenic taxa. Invertebrates (54.6%) and vertebrates (24.5%) were the groups with the highest number of NIS, with Arthropoda, Mollusca, and Chordata being the most represented phyla. Recorded NIS originated from diverse geographic regions, with North and South America being the most frequent. Vertebrates and vascular plants were mostly introduced through intentional pathways (i.e. release and escape), whereas invertebrates and macroalgae arrived mostly through unintentional ways (i.e. contaminant or stowaway). Most of the recorded NIS were introduced in Iberian inland waters over the second half of the 20th century, with a high number of NIS introductions being reported in the 2000s. While only 8% of the recorded NIS appear in the European Union list of Invasive Alien Species of Union concern, around 25% are listed in the Spanish and Portuguese NIS regulations. This study provides the most updated checklist of Iberian aquatic NIS, meeting the requirements set by the EU regulation and providing a baseline for the evaluation of its application. We point out the need for coordinated transnational strategies to properly tackle aquatic invasions across borders of the EU members.
Alien species, checklist, environmental management, estuaries, inland waters, Portugal, regulation, Spain, Western Mediterranean
Compared to terrestrial and marine ecosystems, freshwater and transitional waters (hereafter collectively referred to as inland waters) are especially vulnerable to biological invasions due to their intrinsic environmental features (
The Mediterranean basin is one of the major global hotspots of biodiversity, with the Iberian Peninsula comprising a particularly species-rich area and harbouring high numbers of endemic species (
Most of the above-mentioned studies retrieved NIS records exclusively from published scientific literature, thus overlooking grey literature and unpublished but validated NIS records from private inventories, institutional repositories and official databases. Because of time lags between detecting a NIS in the field and its corresponding publication (
This study updates the information on aquatic NIS occurring in Iberian inland waters by combining knowledge from a diverse panel of experts with an extensive screening of published literature (both international and grey literature), online databases (e.g. GBIF, EASIN and CABI), and technical reports or off-line databases provided by environmental agencies. Through a broad multi-taxa approach including fungi, flora and fauna, this study aims (1) to provide an extensive and updated inventory of NIS introduced in Iberian inland waters, (2) to assess overall patterns in introduction pathways, native regions, and temporal introduction rates, and (3) to discuss the legal coverage of national (Spanish and Portuguese) and European IAS regulation. To make this study as robust as possible, this comprehensive assessment was conducted by an expert-consensus-based approach, which ensured a reliable checklist validation from a taxonomic and state-of-the-art viewpoint, since misidentification or distributional errors are common when no group-specific experts are involved in NIS multi-taxa studies (
The Iberian Peninsula is mostly comprised of the mainland territory of Spain and Portugal. This area is characterised by a wide climatic gradient which extends from the northwestern (temperate oceanic conditions expressed as high rainfall and humidity values, and low continentality) to the southeastern edge (Mediterranean semiarid conditions), including also large parts of the territory exposed to Mediterranean climate with higher continentality. The coastline of the Iberian Peninsula extends over 3,904 km across the Mediterranean Sea (1,670 km), the Atlantic Ocean (1,367 km) and the Cantabrian Sea (867 km). Most of the Iberian territory is framed within major river basins, some of them shared between Spain and Portugal (e.g. Guadiana, Tagus and Douro catchments). Following the European Water Framework Directive (hereafter, WFD) (EC 2000), we considered inland waters as those standing or flowing surface aquatic ecosystems (both fresh and transitional waters) placed across land boundaries. Hence, this term included typically lotic (i.e. rivers and streams) and lentic freshwater ecosystems (i.e. lakes, wetlands and reservoirs), small water bodies (i.e. ponds and pools) and transitional or estuarine aquatic systems influenced by freshwater inputs (i.e. marshlands, brackish waters, estuaries and coastal lagoons). Here, all these aquatic ecosystems were collectively considered and referred to as inland waters. Inland waters from the Balearic and Macaronesia (i.e. Canary Islands, Madeira and the Azores archipelagos) islands were excluded.
An integrative and structured approach based on multiple data sources was applied to generate a comprehensive up-to-date inventory of all aquatic NIS occurring in Iberian inland waters. Firstly, we compiled all available literature on NIS occurrence in Iberian inland waters, including articles published in indexed international journals, grey literature (e.g. articles in regional journals or bulletins), online databases and technical reports. For peer-reviewed literature, we made a query in the Web of Science to retrieve all potential publications focused on NIS in Iberian inland waters. Boolean search terms included all words related to NIS or potential synonyms (i.e. alien, allochthonous, exotic, introduced, invasive, non-native and non-indigenous), target environments (i.e. freshwater, transitional, reservoir/s, lake/s, pool/s, pond/s, river/s, stream/s, estuary/ies and coastal lagoon/s) and the study area (i.e. Iberia, Iberian Peninsula, Spain and Portugal). Resulting publications were screened to generate a list of NIS introduced in Iberian inland waters. This preliminary list of NIS was further complemented with records from grey literature, national technical reports and regional checklists, as well as from the following databases: the European Alien Species Information Network (EASIN; http://easin.jrc.ec.europa.eu), CABI´s Invasive Species Compendium (CABI-ISC; http://www.cabi.org/isc/), the Global Invasive Species Database (GISD; www.iucngisd.org), the EXOCAT database (http://exocatdb.creaf.cat/base_dades/#), the AquaNIS database (http://www.corpi.ku.lt/databases/aquanis/) and the Global Biodiversity Information Facility database (GBIF; http://www.gbif.org/). We recorded all aquatic NIS introduced in Iberian inland waters up to August 2022.
We considered target taxa to be all those NIS able to live in freshwater and/or transitional waters at least during part of their life cycle. Aquatic taxa native from a given Iberian river basin but introduced in other Iberian catchments (i.e. translocated species) were excluded from our inventory. This preliminary list was agreed and validated by a panel of 65 experts in conservation biology and invasion science from Spain and Portugal, covering both types of target aquatic ecosystems (freshwater and transitional environments) and all biotic groups potentially containing aquatic NIS.
Following previous studies (see
For each recorded NIS, the year of introduction (i.e. first detection in the wild) in Europe and both Iberian countries was obtained. This date at European scale was mostly retrieved from EASIN, whereas at the national scale (for Spain and Portugal) was mainly retrieved from scientific literature providing first records for the Iberian Peninsula. When unreported in the literature, we applied a conservative approach and considered the year of the corresponding publication as the year of introduction, following
We analysed which native regions, introduction pathways and functional groups were most prevalent for the recorded NIS. To avoid overrepresentation of those NIS associated with two or more categories, data on these attributes were down-weighted in frequency-related analyses following the strategy of
We recorded 326 non-indigenous taxa in Iberian inland waters, which included 215 clearly established, 96 uncertain and 15 cryptogenic taxa (Suppl. material
Cross-group richness of aquatic non-indigenous species (NIS) recorded in inland waters (including freshwater and transitional waters) from the Iberian Peninsula. Groups correspond to phyla (animals) or divisions (plants). Colours refer to the proportion of NIS belonging to each establishment stage (established, uncertain or cryptogenic). From top to bottom, groups are ranked from the species-richest to the species-poorest.
Most of the aquatic non-indigenous vertebrates (57.5%) were fish (Class Actinopterygii) and they mainly corresponded to NIS well established in Iberian inland waters (34 established; 12 uncertain taxa), with Cyprinidae being the dominant among the 16 recorded families (16 cyprinids out of 46 listed non-indigenous fish species). Reptiles were the second species-richest class among vertebrates (13 NIS, 16.2% of vertebrates) and they were exclusively represented by freshwater turtle species, with only one taxon being clearly established (Trachemys scripta). A similar pattern was found in birds and amphibians, with eight listed NIS for both classes but only two species of birds (Alopochen aegyptiaca and Cairina moschata) and three species of amphibians (Discoglossus pictus, Pelophylax kl. grafi and Xenopus laevis), respectively, were considered as established. On the other hand, the recorded non-indigenous invertebrates were represented by a widely diversified set of species that corresponded to 24 classes including 62 orders. Podocopida (19 NIS) and Decapoda (16 NIS) were the invertebrate orders with most species. Regarding vascular plants, our inventory included submerged, floating and emergent aquatic plants occurring in Iberian inland waters, which generally corresponded to hydrophytes and helophytes. Magnoliopsida (35 NIS) was the dominant group of vascular plants, 12 of these species belonging to the order Alismatales, whereas the class Polypodiopsida hosted three non-indigenous pteridophytes. Among macroalgae, Rhodophyta was the dominant group (20 NIS), whereas Ochrophyta (4 NIS) was much less represented. Lastly, non-indigenous fungi species (3 NIS) were exclusively represented by pathogens belonging to the genera Batrachochytrium and Aphanomyces, which mostly affect amphibians and crayfish, respectively.
Native regions of the recorded NIS corresponded to all geographic areas, with the exception of Antarctica (Fig.
Native regions for the aquatic non-indigenous species (NIS) recorded in inland waters (both freshwater and transitional waters) from the Iberian Peninsula. Results are displayed according to the five main biotic groups considered. As several NIS presented two or more native regions, data were down-weighted to avoid overrepresentation.
We identified four major pathways as responsible of NIS introductions in Iberian inland waters, which totalled about 90% of the recorded taxa: Stowaway (26.1%), Contaminant (25.6%), Escape (21.2%) and Release (17.1%) (Suppl. material
Contribution of the categories of introduction pathways to the arrival of aquatic non-indigenous species (NIS) to inland waters (including freshwater and transitional waters) from the Iberian Peninsula. NIS are grouped into the five major biotic groups considered. As several NIS were introduced through two or more pathways, data were down-weighted to avoid overrepresentation of these categories.
Year of introduction was available for most of the recorded NIS (283/326 for Europe, 280/305 for Spain, and 151/178 for Portugal), thus ensuring representative data on NIS introduction to ascertain temporal arrival rates. From the 1860s to 1960s, the recorded NIS were introduced in European inland waters at a pace of 5–15 species per decade, reaching introduction rates of 30 species per decade over the end of the 20th century (1970s–2000s), though this pace has slightly decreased in the past two decades (Fig.
Temporal introduction rates of aquatic non-indigenous species (NIS) recorded in inland waters (including freshwater and transitional waters) from the Iberian Peninsula. Filled areas represent the cumulative number of introduced NIS in European, Spanish and Portuguese inland waters, whereas lines represent the decadal pace of NIS introduction. Note that the last decade includes two additional years (2020–2021) to allow for reliable data representation.
The delay in aquatic NIS introductions among the three regions (Europe, Spain and Portugal) was only evident for pairwise comparisons between national and continental scales (Fig.
Scatterplots and linear regression functions (red line) of the year of introduction of aquatic non-indigenous species (NIS) in three regions: Europe vs Spain (a), Europe vs Portugal (b) and Spain vs Portugal (c). Each dot represents a given NIS, with colour indicating the five considered biotic groups. Dashed lines represent the equality line and grey shadow correspond to confidence intervals.
The recorded NIS spanned a wide variety of functional groups (Suppl. material
Only 26 (8.0%) out of the 326 recorded NIS are included in the Union List of the EU Regulation (Fig.
Venn diagrams representing the legal coverage of the official regulation lists for aquatic non-indigenous species (NIS) in Europe, Spain and Portugal. Large circles represent the pool of 326 NIS introduced in Iberian inland waters (Iberian NIS list), whereas smaller circles represent the number of aquatic Iberian NIS which are listed in the Union IAS list, in the Portuguese IAS list, in the Spanish Catalogue of Invasive Alien Species (Spanish IAS list) and in the list of allochthonous species able to impact on Spanish native biodiversity (Spanish Allochthonous catalogue). The number of NIS exclusive to and shared by each list is indicated within circles.
Our multi-taxa assessment provides the most updated and comprehensive inventory of NIS occurring in freshwater and transitional waters from the Iberian Peninsula (mainland Spain and Portugal). By gathering expert knowledge, published literature and other available data sources, we recorded 326 taxa of fungi, macroalgae, vascular plants, invertebrates and vertebrates already introduced and detected in Iberian inland waters, including established, uncertain and cryptogenic taxa. As compared to other reference checklists (Table
Number of non-indigenous species (NIS) reported by the main previous studies providing reference checklists in the study area or related geographical regions. NA means no data available.
Reference checklist | Target environments | Target taxa | Study area | N established | N uncertain | N cryptogenic | N total |
---|---|---|---|---|---|---|---|
This study | Freshwater and transitional | Fungi, macroalga, plants, and animals | Iberian Peninsula | 215 | 96 | 15 | 326 |
|
Transitional | Animals | Spanish Mediterranean coast | 93 | 30 | 6 | 129 |
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Freshwater and transitional | Plants and animals | Iberian Peninsula | 103 | 21 | 2 | 126 |
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Freshwater and transitional | Animals | Iberian Peninsula | 125 | 18 | 6 | 149 |
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Freshwater | Animals | Mainland and insular Portugal | 67 | NA | NA | 67 |
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Freshwater | Vascular plants | Europe | NA | NA | NA | 60 |
Gofas et al. 2017 | Marine | Molluscs | Mainland and insular Spain | 36 | NA | 2 | 38 |
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Freshwater | Macrophytes | Iberian Peninsula | 20 | NA | NA | 20 |
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Marine and transitional | Algae, plants and animal | Mainland and insular Portugal | 78 | 46 | NA | 133 |
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Freshwater (rivers) and riparian | Plants | Iberian Peninsula | NA | NA | NA | NA |
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Freshwater | Animals | Iberian Peninsula | NA | NA | NA | 78 |
|
Terrestrial and freshwater | Plants | Spain | NA | NA | NA | 176 |
In addition, most of the reference checklists (Table
Aquatic non-indigenous vertebrates and invertebrates were generally native to North America and temperate Asia, though a relevant proportion of taxa were also originated from Europe, being all these patterns congruent with previous studies (
Unlike vertebrates, invertebrate NIS were mostly introduced in Iberian inland waters through two unintentional pathways: contaminant and stowaway. They were native to almost all geographic regions, with North America and temperate Asia being the predominant. Previous studies have shown that most estuarine NIS of non-mollusc and non-arthropod invertebrates (e.g. annelids or platyhelminthes) reached the Iberian coast as hitchhikers through ballast water or hull fouling vessels from global maritime trade (
The recorded non-indigenous aquatic vascular plants are mainly native to South and North America, and most of them were introduced through escape and release, although a non-negligible number of them also arrived as contaminants. Moreover, up to five different introduction pathways were exclusively associated with the arrival of some non-indigenous aquatic plants (e.g. Heteranthera limosa) (Suppl. material
Almost half of the recorded non-indigenous macroalgae was native to the Pacific Ocean and considered Lessepsian migrants, whereas the other half was native to the remaining geographic regions and introduced presumably passively through maritime traffic (
Legislative instruments (e.g. regulation lists or catalogues) are developed at European, national and even regional level to prevent the introduction and spread of enlisted NIS through direct management actions. The Regulation (EU) No 1143/2014 established a list of IAS of Union concern which entails that all EU Member States must implement specific management actions to prevent new introductions and further spread across European countries (
About 17.6% of the listed NIS in the present study have their native range within Europe, thus placing important challenges for transnational regulation and cooperation at Europe scale. This situation may lead to a complex conservation paradox when some aquatic species are native and even threatened in certain EU Member States but they have been introduced and become invasive in others (
On the other hand, our assessment on legal coverage provided by regulation lists highlighted important taxonomic-related biases. For instance, the Union list does not include any non-indigenous mollusc despite most of them being non-indigenous to Europe and some are already causing important ecological and economic impacts in Iberian inland waters (
The introduction of NIS in Iberian inland waters is a long-lasting process affecting many facets of biodiversity, but also local economies and public health. Managing aquatic NIS in the Iberian Peninsula requires a well-coordinated strategy among decision-makers and stakeholders. Nowadays, the increase of human pressure on natural habitats, the climate change and the expanding international trade are promoting the entry, spread, and establishment of new non-native taxa, particularly in inland waters. Hence, effective NIS management requires updated and detailed information on main introduction-related attributes. This study provides a comprehensive multi-taxa inventory of aquatic NIS introduced in Iberian freshwater and transitional waters. This baseline information is delivered through a freely available database intended to become a key tool for improving NIS prevention, monitoring and management at Iberian level. For instance, our assessment may serve as a useful resource for managing NIS introduction pathways into freshwater and estuarine ecosystems, as well as for communicating the magnitude of aquatic invasions to all related authorities and stakeholders. Moreover, this inventory also aims to meet the requirements on updated NIS data stated by the EU Regulation on IAS. Ultimately, our study provides valuable information on the implementation of other EU policies with implications on NIS management, such as the EU Biodiversity Strategy to 2030, the Birds and Habitats Directives, the Marine Strategy Framework Directive, and the Water Framework Directive.
This study was supported by the LIFE INVASAQUA project (Aquatic Invasive Alien Species of Freshwater and Estuarine Systems: Awareness and Prevention in the Iberian Peninsula) (LIFE17 GIE/ES/000515) funded by the EU LIFE Program. The Fundación Biodiversidad (Government of Spain) and the Government of Navarre financially supported specific actions into the LIFE INVASAQUA. J.M. Z.-M. is supported by a postdoctoral grant funded by the Spanish Ministry of Science and Innovation and the European Union NextGeneration EU/PRTR (FJC2021-046923-I). F.R. is supported by Foundation for Science and Technology through an individual contract (CEEC/0482/2020). I.B. and J.A.C. were funded by the Basque Government (IT1487-22). J.E. has a Ph.D. scholarship (SFRH/BD/140556/2018) funded by FCT, Portugal. F.B. is supported by Foundation for Science and Technology through an individual contract (CEEC/01896/2021). C.C. was supported by Portuguese national funds to the CEG/IGOT Research Unit (UIDB/00295/2020 and UIDP/00295/2020), through FCT - Fundação para a Ciência e a Tecnologia, I.P. F.C.A, was funded by CEF, a research unit of FCT, Portugal (UIDB/00239/2020). A.A. H.-R. was supported by a predoctoral grant from the University of Murcia (R-483/2023).
Conceptualization & Coordinating groups: FJ Oliva-Paterna, JM Zamora-Marín, F Ribeiro, PM Anastácio, B Gallardo, E García-Berthou, P García-Murillo, F Cobo, R Miranda, D Boix, L Medina, F Morcillo, J Oscoz, A Guillén, A Arias, JA Cuesta. Data curation: A Ruiz-Navarro, F Ribeiro, AA Herrero-Reyes, JM Zamora-Marín and FJ Oliva-Paterna. Formal analyses: JM Zamora-Marín, A Ruiz-Navarro, A Guerrero-Gómez and FJ Oliva-Paterna. Writing - Original draft: JM Zamora-Marín, A Ruiz-Navarro, FJ Oliva-Paterna, FJ Oficialdegui. Supervision and Writing - review & editing: FJ Oliva-Paterna, JM Zamora-Marín, FJ Oficialdegui, F Ribeiro, PM Anastácio, B Gallardo, E García-Berthou, P García-Murillo, R Miranda, D Boix, A Arias, JA Cuesta. Investigation, Visualization & Review: All authors. Project Administration: FJ Oliva-Paterna. All authors have reviewed and contributed to improve the text and figures.
We thank many experts who have contributed to this NIS inventory by providing useful records, suggestions and opinions through personal communications: Núria Bonada, Ramón De Miguel, Estibaliz Díaz, Ignacio Doadrio, Rocío Fernández-Zamudio, Nati Franch, Pedro M. Guerreiro, Emilio Laguna, Pedro Leunda, Francisco Martínez-Capel, José A. Molina, Jorge Paiva, Angel Pérez-Ruzafa, Carla Pinto and Manuel Toro.
All data of the recorded NIS
Data type: xlsx
Explanation note: Excel file containing all data of the recorded NIS, as well as a corresponding legend for an easier interpretation and all the references supporting the NIS inventory.
Supplementary images
Data type: docx
Explanation note: fig. S1: Number of aquatic non-indigenous species (NIS) recorded in Iberian inland waters (including freshwater and transitional waters) across taxonomic classes; fig. S2: Number of native regions (a) and introduction pathways (b) associated to the five major biotic groups containing all aquatic non-indigenous species (NIS) introduced in Iberian inland waters (including freshwater and transitional waters); fig. S3: Contribution of the seven categories of introduction pathways to the arrival of aquatic non-indigenous species (NIS) to Iberian inland waters (both freshwater and transitional waters); fig. S4: Temporal variation in the overall contribution of the seven introduction pathways to the arrival of aquatic non-indigenous species (NIS) to Iberian inland waters (including freshwater and transitional waters); fig. S5: By-country distribution of first European records of aquatic non-indigenous species (NIS) introduced in Iberian inland waters (including freshwater and transitional waters); fig. S6: Distribution across functional groups (i.e. trophic groups) of aquatic non-indigenous species (NIS) recorded in Iberian inland waters (including freshwater and transitional waters); fig. S7: Legal coverage of official regulation lists for aquatic non-indigenous species (NIS) introduced in Iberian inland waters (including freshwater and transitional waters); fig. S8: Distribution of native regions (a) and introduction pathways (b) across taxonomic classes containing all aquatic non-indigenous species (NIS) introduced in Iberian inland waters (including freshwater and transitional waters)