Invasive speciesInvasive species

Invasive species

Introduced plant species such as Water hyacinth (Eichhornia crassipes), Ludwigia peruviana, Salvinia sp. and Mimosa pigra have adversely affected the ecological character and biodiversity of wetlands across Australia; introduced animals such as pigs (Sus sp.), cane toads (Rhinella marina) and European carp (Cyprinus carpio) are also well known for their destructive impacts on wetland areas. There is also a constant risk of new introductions of exotic pasture, aquarium and garden species, such as Sea spurge (Euphorbia paralias), and exotic marine pests from ballast water and hull transport. Of specific concern for migratory shorebirds is the introduction of exotic marine pests resulting in loss of benthic food sources at important intertidal habitat (Neira et al. 2006). Predation by invasive animals, such as cats (Felix catus) and foxes (Vulpes vulpes) in Australia has not been quantified, but anecdotal evidence suggests some individuals are taken as prey.

Outside Australia, invasive species are negatively affecting coastal habitat, causing local species to be displaced by species accidentally or deliberately introduced from other areas. With an increase in global shipping trade the influx of such species is increasing, especially in the coastal zone. Examples include Spartina grass in China, Zebra mussels (Dreissena polymorpha), and Tilapia (Tilapia spp.) in wetlands and estuaries and along coasts (MacKinnon et al. 2012).