It said invasive alien species have been a major factor in 60% and the only driver in 16% of recorded global animal and plant extinctions. Besides biological invasion by alien species, other four major factors responsible for extinctions include changing land- and sea-use, over exploitation, climate change and pollution.
The report – approved on Saturday in Bonn, Germany by representatives of the 143 member countries of IPBES including India – cited several examples from across the globe, including India, noting how such invasive species resulted in complete wipe out of certain native species. It said at least 218 invasive alien species have been responsible for more than 1,200 local extinctions.
Noting that the invasive alien invertebrates are the most frequently reported taxonomic group with an impact on nature’s contributions to people, particularly provision of food, the report flagged how Mytilopsis sallei (Caribbean false mussel) has displaced native clams and oysters that are locally important fishery resources in India. The list of species also include water hyacinth and lantana camara which are aliens to India.
The report shows that 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. Most negative impacts are reported on land (about 75%) – especially in forests, woodlands and cultivated areas – with considerably fewer reported in freshwater (14%) and marine (10%) habitats.
“It would be an extremely costly mistake to regard biological invasions only as someone else’s problem. Although the specific species that inflict damages vary from place to place, these are risks and challenges with global roots but very local impacts, facing people in every country, from all backgrounds and in every community – even Antarctica is being affected,” said Anibal Pauchard of Chile, co-chair and one of the authors of the report.
The authors of the report emphasize that not all alien species become invasive – invasive alien species are the subset of alien species that are known to have become established and spread, which cause negative impacts on nature and often also on people.
They noted that only 6% of alien plants; 22% of alien invertebrates; 14% of alien vertebrates; and 11% of alien microbes are known to be invasive, posing major risks to nature and to people.
On a more positive note, the report highlights that future biological invasions, invasive alien species, and their impacts, can be prevented through effective management and more integrated approaches. “The good news is that, for almost every context and situation, there are management tools, governance options and targeted actions that really work,” said Pauchard.