Invasive alien species on islands: impacts, distribution, interactions and management

Abstract

SUMMARYInvasive alien species (IASs) on islands have broad impacts across biodiversity, agriculture, economy, health and culture, which tend to be stronger than on continents. Across small-island developing states (SIDSs), although only a small number of IASs are widely distributed, many more, including those with greatest impact, are found on only a small number of islands. Patterns of island invasion are not consistent across SIDS geographic regions, with differences attributable to correlated patterns in island biogeography and human development. We identify 15 of the most globally prevalent IASs on islands. IAS impacts on islands are exacerbated through interactions with a number of other global change threats, including over-exploitation, agricultural intensification, urban development and climate change. Biosecurity is critical in preventing IAS invasion of islands. Eradication of IASs on islands is possible at early stages of invasion, but otherwise is largely restricted to invasive mammals, or otherwise control is the only option. Future directions in IAS management and research on islands must consider IASs within a broader portfolio of threats to species, ecosystems and people's livelihoods on islands. We advocate for stronger collaborations among island countries and territories faced with the same IASs in similar socio-ecological environments.

A review of mammal eradications on Mediterranean islands

“…Biosecurity is critical in preventing alien species invasions on islands, as well as in protecting from reinvasion those islands where they have been eradicated (see, e.g. Russell et al ). However, despite reinvasion often occurring on Mediterranean islands, very little information was available about biosecurity.…”

“…Island ecosystems are especially prone to the negative consequences of alien species introductions (see, e.g. Bellard et al , Holmes et al ), and control or eradication of invasive alien species is widely recommended and undertaken by researchers and conservation organisations to mitigate the impact of introduced invasive species (Russell et al ). Among invasive alien species, mammals have an important role: as an example, 14 out of 100 species considered highly invasive by experts are mammals (Luque et al ).…”

Alien versus native species as drivers of recent extinctions

“…Alien consumers introduced to a community where functionally similar species are absent are more likely to disrupt native species populations (eg Ricciardi and Atkinson ; Russell et al . ). Across different biomes and habitat types, alien predators and herbivores cause more damage to native populations than do native consumers (Salo et al .…”

Integrating Insights from Social-Ecological Interactions into Sustainable Land Use Change Scenarios for Small Islands in the Western Indian Ocean

“…Population growth also increases requirements for wastewater treatment and can lead to pollution from nutrient loading if these needs are not met (i.e., from solid waste which is disposed of in sink pits). Introduced invasive species, such as crop pests, can have detrimental and unpredictable effects on endemic species [26]. Urbanisation and resource investments are another growing source of influence for socio-economic development on small islands.…”