Invasive alien species are one of the biggest drivers of biodiversity loss, and pose a serious threat to ecosystems, food security and livelihoods around the world, a team of international researchers warned on Monday.
They released a comprehensive report after nearly five-year-long global research on the alien species-plants, animals or microorganisms, which are introduced into areas where they are not native.
"More than 37,000 alien species have been introduced by many human activities to regions and biomes around the world. More than 3,500 of these are harmful invasive alien species-seriously threatening nature, nature's contributions to people and good quality of life," the experts said.
According to the report, increasing levels of global trade and human travel is facilitating intentional and unintentional movement of species beyond their indigenous range, and threatening natural habitats and native species around the world.
Professor Helen Roy, a lead author of the report by the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), warned that the increase of invasive alien species and their negative impacts are likely to grow in the coming years.
"The accelerating global economy, intensified and expanded land- and sea-use change, as well as demographic changes are likely to lead to increases in invasive alien species worldwide," she said.
"Even without the introduction of new alien species, already established alien species will continue to expand their ranges and spread to new countries and regions. Climate change will make the situation even worse," she added.
According to the report, 34% of the impacts of biological invasions were reported from the Americas, 31% from Europe and Central Asia, 25% from Asia and the Pacific, and about 7% from Africa.
Invasive alien species were most damaging on islands, with numbers of alien plants now exceeding the number of native plants on more than 25% of all islands.
People with direct dependence on nature, such as Indigenous peoples and local communities, were under greater risk from the threat of invasive alien species.
According to the report's findings, at least 218 invasive alien species were responsible for more than 1,200 local animal or plant extinctions.
Besides dramatic changes to biodiversity and ecosystems, biological invasions also have a serious impact on economy.
The global economic cost of invasive alien species was estimated $423 billion annually in 2019, with costs having at least quadrupled every decade since 1970, according to the report.
In order to prevent future biological invasions, the experts underlined the importance of raising public awareness, adopting coherent policies and taking stronger measures. They suggested "border biosecurity" and strictly enforced import controls could be useful, as they worked in many instances.
"One of the most important messages from the report is that ambitious progress in tackling invasive alien species is achievable," said Professor Peter Stoett.
"What is needed is a context-specific integrated approach, across and within countries and the various sectors involved in providing biosecurity, including trade and transportation; human and plant health; economic development and more. This will have far-reaching benefits for nature and people," he added.
