JL Molnar et al. – Supplemental information WebPanel 1. Data collection methods We have developed a data framework in which we doc- o Invertebrate – arthropod – other ument information about individual invasive species, o Invertebrate – cnidarian including their non-native range extent, threat to native o Invertebrate – ctenophore biodiversity, and introduction pathways. Building on o Invertebrate – echinoderm existing datasets, we have integrated information from o Invertebrate – mollusk a wide variety of sources and developed a geographi- o Invertebrate – mollusk (snail) cally referenced Microsoft Access database of marine o Invertebrate – platyhelminth invasive species. o Invertebrate – porifera (sponges) Our aim was to enable efficient and consistent data o Nematode collection through effective design of the database and o Plant criteria (described below). To aid in this, we used data- o Protozoa base fields common to other data collection efforts o Tunicate wherever possible (eg IUCN SSC’s Global Invasive o Vertebrate – amphibian Species Database [GISD], www.issg.org/database). This o Vertebrate – bird allowed us to collect data from those sources more o Vertebrate – fish efficiently, and will make it easier for others to incorpo- o Vertebrate – mammal rate our data into their work. o Vertebrate – reptile We present data only on marine species in this publi- o Virus cation, but we are collecting data on freshwater and terrestrial species in parallel efforts, using consistent References methods. In an index of references, we noted bibliographic citation Information about data collected in our database and information and the type of documentation for each how we made decisions on documenting information is source. provided below.The database is available at http://con- serveonline.org/workspaces/global.invasive.assessment. Type of documentation – measure of reliability of data used to score, based on Cal-IPC (2003) General species information • Peer review (PR) – published, peer-reviewed scientific We collected data on species that are established evidence or floras/faunas outside of their native range and have the potential • Report (RE) – non-peer-reviewed, published documents to impact native species and biodiversity. Species that and reports occur in and impact human-dominated habitats (eg • Compilations (COMP PR/RE) – source that is a compila- aquaculture) have been included, but only their tion of data from PR and RE sources (eg existing data- impact on natural habitats and native biodiversity has bases of invasive species) been recorded. • Expert opinion (EO) – confirmed, unpublished observa- tions by a qualified professional We documented basic information about each species, • Anecdotal (AN) – unconfirmed, anecdotal information including: Geography and habitat • Scientific name In addition to non-native occurrences by ecoregion • Common name (described below), we collected descriptive information • Whether the species lives in marine, freshwater,and/or about distribution and habitats for each species, where terrestrial habitats data allowed. References for these data were docu- • Higher taxonomic group (list based on “organism type” mented. in GISD): • Origin – description of the native range of a species o Algae • First introduction – description of the first reported o Ascidian introduction for which we found evidence o Bacterium • Non-native distribution by country and other geographic o Bryozoan units – Our focus was on documenting non-native o Ectoprocta ranges by ecoregion, but many data sources reported o Fungus distributions using different units. We have captured o Invertebrate – annelid this information in text fields. o Invertebrate – arthropod – crustacean • Habitat description – text field describing the habitats in o Invertebrate – arthropod – insect which a species is found © The Ecological Society of America www.frontiersinecology.org Supplemental information JL Molnar et al. WebPanel 1. Data collection methods – Continued • Habitat – Species were noted as living in one or more The categories used to assign each score were devised of the marine habitats in the following list. To maintain so that they can be applied consistently to different types consistency with existing databases, we based it on the of species and to those living in marine, freshwater, and habitat list in the GISD and included some additional terrestrial habitats. marine habitat classes. This is not a formal classification Scores were assigned globally for each species, not for of marine or coastal habitats, and we would also point specific occurrences. For consistency, we used the worst out that the habitat classes are not mutually exclusive – documented case to score a species. If data were many are nested or overlapping. Where relevant we ambiguous, we were conservative in assigning higher documented multiple habitats for species: scores. Below are descriptions of how we scored the threat of o Aquaculture facilities o Benthic species and collected supporting data. o Brackish water o Canals o Coastland o Coral reefs Ecological impact o Estuaries/bays o Fouling communities Ecological impact measures the severity of the impact of o Intertidal zones o Mangroves a species on the viability and integrity of native species o Marine habitats o Rocky habitats and natural biodiversity. The following information was o Shallow lagoons o Wetlands captured in the database: Non-native occurrence by ecoregion Score We have documented the non-native range of each 4 – Disrupts entire ecosystem processes with wider species, defining non-native occurrences as ecoregions in abiotic influences which a species is established outside of its native range 3 – Disrupts multiple species, some wider ecosystem (marine ecoregions: www.nature.org/MEOW; Spalding function, and/or keystone species or species of et al. 2007). Reference(s) were included for each ecore- high conservation value (eg threatened species) gional occurrence. 2 – Disrupts single species with little or no wider As a rough indicator of the reliability of these data, we ecosystem impact also noted whether an ecoregional occurrence was 1 – Little or no disruption within the geographic scope of references used. For U – Unknown or not enough information to deter- example, if a database of invasive species in the mine score Mediterranean Sea states that a species is also found in the Philippines, we included that occurrence in the data- Text Description – succinct description to support base, but noted that it was outside of the geographic score, including, if data allowed, description of the scope of the data source (until we can confirm the wider abiotic influences, ecosystem and species dis- occurrence with a source from that region). ruptions, and including geographic variation in impact if applicable Threat scores Species were assigned a score for each of the following Sources – cited documentation for score and (where data allowed) to indicate the magnitude of the descriptive text threat that it poses to native biodiversity: “ecological impact”, “geographic extent”, “invasive potential”, and Species were scored based on the worst documented “management difficulty”. case, with conditions in that case noted in the text Our four threat scores are based on systems pro- description field. Occurrences and conditions where posed by Salafksy et al. (2003), NatureServe (2004), and there was less of an impact are described in the text California Invasive Plant Council (Cal-IPC 2003).The fol- description as well. lowing chart roughly compares the criteria of each to We were conservative in assigning higher scores when our scores: data were ambiguous. For example, if a species is known Salafsky et al. NatureServe Cal-IPC Ecological impact Severity/synergism Ecological impact Ecological impact Geographic extent Scope Current distribution and abundance Ecological amplitude and distribution Invasive potential Timing/likelihood Trend in distribution and abundance Invasive potential Management difficulty Reversibility Management difficulty na Type of documentation na na Level of documentation www.frontiersinecology.org © The Ecological Society of America JL Molnar et al. Supplemental information WebPanel 1. Data collection methods – Continued to have economic impacts (eg fouling ship hulls), but its 3 – Established in no more than two adjoining ecore- impacts in natural habitats have not been studied, we gions would assign it a low ecological impact score, pending 2 – More than one occurrence within one ecosystem more available data. Potential but unverified impacts 1 – Single locality were noted in the text description. Some examples of the types of impacts that we As an additional description of the non-native distribu- assigned to each of the categories: tion of a species, we noted the following, if data allowed: 4 – Causing large scale changes such as: altering commu- Locally patchy – sightings or small communities estab- nity structure, causing localized to widespread lished in localized area extinctions, altering native level of activity (eg clog- Locally pervasive – dominant to similar flora/fauna in ging waterways, altering natural topography) localized community 3 – Disrupting changes impacting more than a small Regionally patchy – small, independent populations number of species without causing localized extinc- spanning two or more ecoregions tions, competition with threatened or keystone Regionally pervasive – dominant characteristics within species, changing balance in ecosystem all/most