The first global register of alien species shows that a fifth of 6,400 plant and animals catalogued are causing harm.
Scientists have said that some of the biggest factors in their spread are ballast water in ships for marine species and trade in ornamental plants on land.
Data for 20 countries has been released this week, with the aim of completing the register by the end of the year.
Invasive species are living with things that are not native to an ecosystem. They can harm the environment, the economy, or human health. For example, rats can cause birds extinctions on some islands, while the crown-of-thorns star fish is smothering some areas of the Great Barrier Reef.
Providing the first country-wide checklist for introduced and invasive species is the Global Register of Introduced and Invasive Species (GRIIS). Melodie McGeoch of the IUNC Invasive Species Specialist Group in Rome, Italy, said: “The GRIIS is not about any single one of these, but about all of them and about the many thousands of species that have become naturalised outside of their historical ranges across the world as a result of human activity.”
She added: “Until now there has been highly uneven distribution of knowledge on invasive species globally.”
The Register will generate information that is available publicly on all kinds of invasive species across the world.
Currently, the number of species catalogued for the 20 countries studied, ranges from 77 in Mongolia to 2,107 in South Africa. Of the 6,414 species across the 20 countries, more than 80% had evidence of impact in at least one or two countries.
Cross-border trade and transport are the main drivers of introductions of new species. According to researchers, it is only by accurately identifying and cataloguing animals and plants on land and at sea that biological invasions can be managed.
The study is published in the journal Scientific Data.