Invasive species pose a significant threat to biodiversity and with globalization increasing the widespread transport of these species, it is essential to have a global perspective to inform strategic responses. This ongoing assessment is quantifying the geographic distribution of the threat of invasive species to biodiversity at the global scale.

We are developing a global database of invasive species in freshwater, terrestrial, and marine environments. Invasive species have been highlighted as one of the major pressures on native biodiversity; however, even basic data on the presence or absence of invasive species at a global level are often inconsistent or only available for limited geographic areas. We are developing the first global, comprehensive, and geographically explicit database of the impact of invasive species, by compiling data from a wide variety of resources. In addition to species information such as habitat preference, modes of introduction, native range, and non-native range by ecoregion, we are also scoring each species to indicate its threat to native biodiversity using the following categories:

• Ecological Impact
• Geographic Scope
• Invasive Potential
• Management Difficulty

This assessment will not only be important in the study of invasive species at the global scale, but also can inform policies to limit the spread of these species by identifying which species are likely to be the most harmful to native ecosystems, the current distributions of these species, and how they are likely to be transported to new regions.

Preliminary freshwater and marine results can be found in the 2015 Goal global data (TNC intranet).

The Marine Invasives Database is now available to the public in a ConserveOnline workspace Assessing the Global Threat of Invasive Species to Marine Biodiversity.

This work is published in:  Jennifer L Molnar, Rebecca L Gamboa, Carmen Revenga, Mark D Spalding. 2008.  Assessing the global threat of invasive species to marine biodiversity.  Frontiers in Ecology and the Environment. 6, doi:10.1890/070064.

For more information, please contact the team at conservationgateway@tnc.org