“It should also include careful vetting of species proposed for introduction to an area, as done by organisations such as the European and Mediterranean Plant Protection Organization (EPPO), to filter out those species that are risky in terms of their potential to establish and have negative impacts”.
During the study, scientists combed through existing data for 423 mainland regions and 186 island regions, looking at eight different groups including ants, amphibians, freshwater fish, birds, spiders, reptiles, mammals, and vascular plants. These hotspots of alien species are the Hawaiian Islands, the North Island in New Zealand, and the Lesser Sunda Islands in Indonesia. “Prevention is better than cure with invasive species”, Dawson said.
The study is carried out by an global team, led by Dr Wayne Dawson from the Durham University, who analyzed existing data looking at eight groups including amphibians, ants, birds, freshwater fish, mammals, reptiles, spiders and vascular plants across 186 island and 423 mainland regions. These include guppies among fish (now globally widespread) and feral pigs among mammals.
New Zealand is on the second place, where plants represent most of the invasive populations on the islands. In addition, approximately half of New Zealand’s plant life is made up of established alien species. A great prevalence of rats, cats, and possum also elevated the issue surrounding indigenous birds’ survival.
“Both regions are remote islands that used to be very isolated, lacking some groups of organisms altogether – such as mammals, for instance”, Franz Essl, an ecologist at the University of Vienna in Austria, said in a news release.
Where are alien, or invasive, species most abundant?
The study also revealed that several alien plants and animals were also present in the state of Florida in the United States.
Islands and mainland coastal regions were found to be the most likely places to be colonised by foreign species, their report in the journal Nature Ecology & Evolution says.
An worldwide team of researchers, led by Durham University, UK, has provided the first global analysis of established alien species.
Study results revealed certain factors that affect alien species, such as the wealth of a region, the density of human population, and the region’s climate.
For this reason, scientists called for more global efforts to prevent further introductions of plants and animals into vulnerable ecosystems.