Europe now has 1,517 alien species of insects, worms, mussels and other invertebrates, a tally that is growing steadily thanks to globalisation and climate change, French researchers said on Friday. The numbers "have increased markedly in recent years," the French National Institute for Agronomic Research (Inra) said in a press release.
From 2000-2007, on average 19 "exotic" species established themselves in Europe each year, compared with only 10 each year between 1950 and 1975, it said. Asia, followed at a distance by North America, is the major source for these alien species. Less than 10 percent of the newcomers were deliberately introduced into Europe.
The rest either hitched a ride in container vessels, trucks and planes through international trade, or migrated to Europe and discovered a habitat niche due to today's warmer climate.
Overall, Europe has 10,822 alien species, if fish, birds, mammals and vegetation are included. Around two-thirds of the aliens are plants.
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