Number of Harmful Invasive Species by Marine Ecoregion

Number of harmful species that have invaded marine habitats, by marine ecoregion.

The occurrence and ecological impact of marine invasive species were compiled in a geographically referenced database by Molnar et al. (2008). Information about 329 species was systematically collected from a wide variety of global, regional, national, and subnational data sources. Non-native distributions were documented by marine ecoregion. The threat of each species to native biodiversity was scored using the following categories: 4, disrupts entire ecosystem processes with wider abiotic influences; 3, disrupts multiple species, some wider ecosystem function, and/or keystone species or species of high conservation value (e.g., threatened species); 2, disrupts single species with little or no wider ecosystem impact; 1, little or no disruption. Species in the top two categories (scores of 3 or 4) are considered “harmful invasive species” in this atlas (n=187), and the number of these are displayed in the map by ecoregion.

These data were derived by The Nature Conservancy, and were displayed in a map published in The Atlas of Global Conservation (Hoekstra et al., University of California Press, 2010). More information at http://nature.org/atlas.

Data derived from:
Molnar, J. L., R. Gamboa, C. Revenga, and M. Spalding. 2008. Assessing the global threat of invasive species to marine biodiversity: Framing the big picture. Frontiers in Ecology and the Environment 6, no. 9: 485–492.