Alien species pathways to the Galapagos Islands, Ecuador

• Published in: PloS one 2017-09, Vol.12 (9), p.e0184379-e0184379
• Main Authors: Toral-Granda, M Verónica, Causton, Charlotte E, Jäger, Heinke, Trueman, Mandy, Izurieta, Juan Carlos, Araujo, Eddy, Cruz, Marilyn, Zander, Kerstin K, Izurieta, Arturo, Garnett, Stephen T
• Format: Article
• Language: English
• Subjects: Aircraft; Aircraft - statistics & numerical data; Animals; Archipelagoes; Biodiversity; Biology and Life Sciences; Biosecurity; Cargo aircraft; Cargo capacity; Cargo ships; Climate change; Commodities; Dispersal; Earth Sciences; Ecology and Environmental Sciences; Ecosystem; Ecuador - epidemiology; Engineering and Technology; Fruit; Hazards; Historic sites; Human populations; Humans; Introduced species; Introduced Species - statistics & numerical data; Introduced Species - trends; Islands; Islands - epidemiology; Marine ecosystems; Nonnative species; People and places; Plants; Plants (botany); Population decline; Population Dynamics; Reviews; Seed Dispersal; Ships - statistics & numerical data; Species; Terrestrial environments; Tourism; Tourists; Transients and Migrants - statistics & numerical data; Transport vehicles; Travel - statistics & numerical data; Vegetables; World Heritage Areas
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0184379

Alien species, one of the biggest threats to natural ecosystems worldwide, are of particular concern for oceanic archipelagos such as Galápagos. To enable more effective management of alien species, we reviewed, collated and analysed all available records of alien species for Galápagos. We also assembled a comprehensive dataset on pathways to and among the Galápagos Islands, including tourist and resident numbers, tourist vessels, their itineraries and visitation sites, aircraft capacity and occupancy, air and sea cargo and biosecurity interceptions. So far, 1,579 alien terrestrial and marine species have been introduced to Galápagos by humans. Of these, 1,476 have become established. Almost half of these were intentional introductions, mostly of plants. Most unintentional introductions arrived on plants and plant associated material, followed by transport vehicles, and commodities (in particular fruit and vegetables). The number, frequency and geographic origin of pathways for the arrival and dispersal of alien species to and within Galápagos have increased over time, tracking closely the increase in human population (residents and tourists) on the islands. Intentional introductions of alien species should decline as biosecurity is strengthened but there is a danger that unintentional introductions will increase further as tourism on Galápagos expands. This unique world heritage site will only retain its biodiversity values if the pathways for invasion are managed effectively.