Shipping and water diversion pathways expand the global area at risk from invasive freshwater bivalves

Abstract

Invasive species affect freshwater ecosystems and economies worldwide, with their dispersal facilitated by human activities such as shipping and large water transfer projects. Here, we use the golden mussel (Limnoperna fortunei) as a model species and develop an integrated framework that combines a dispersal model for introduction risk with a species distribution model for establishment risk, using global shipping routes and water diversion projects as the main pathways. Our simulations reveal an expansion of high-risk basins over time, particularly after the 1990s, with coastal basins acting as invasion bridgeheads from which populations can spread inland. Several basins in North America, Europe, Australia, the Indochina Peninsula and the Amazon basin, although not yet invaded, emerge as environmentally suitable and increasingly connected, indicating elevated future invasion risk. Our study highlights the importance of implementing management strategies for invasive species, such as ballast water treatment and installing prevention measures in water diversion/transfer schemes.