Biological Invasion by 3,500 Alien Species Causing Economic Loss and Biodiversity Crisis

On September 4, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services released the IPBES Invasive Alien Species Assessment. The report focused on invasive alien species and was prepared by 86 experts from 49 countries, drawing more than 13,000 scientific references.

In this exhaustive analysis, scientists discuss the major global threats of invasive alien species to nature, economies, food security, and health. It also provides the evidence, tools, and options governments can use to achieve new goals on invasive alien species.

Experts describe the key role of invasive alien species in driving 60% of record global extinctions. These species were also considered the only driver in 16% of documented extinctions of plants and animals.

The alien species have become a threat to biodiversity through humans. Man-made activities were introducing them to all regions and biomes of the world. Scientists assume that there are currently 37,000 established alien species that have deliberately or accidentally arrived with humans. About 3,500 of them are documented as harmful and are classified as invasive. Moreover, the number of invasive alien species increases at an unprecedented rate of 200 annually.

According to the study authors, the negative effects of alien species are rapidly increasing in all regions of the world and are predicted to do so in the future. Even if no new species is introduced, the existing populations of invasive alien species will continue to spread through various ecosystems.

Economical Impact of Biological Invasion

One of the report's highlights is quantifying the damages caused by invasive alien species. Many of these species have been introduced for commercial purposes, but IPBES emphasized that the benefits provided by the invasive alien species to humans do not reverse their negative effects. These include harm to human health, water security, livelihoods, and food security.

Every year, the invasion costs $423 billion, with the vast majority (92%) coming from their negative impact on the environment and humans. Meanwhile, the most frequently reported impact has something to do with the reduction in food supply. The remaining 8% belongs to the management expenditures for biological invasions. The report also noted that the global economic costs of these species have quadrupled every decade since 1970.

Consequences of Biological Invasion on Biodiversity

Biological invasion is also one of the five major causes of the biodiversity loss crisis currently experienced by our planet. In 2018, IPBES conducted a study on planetary species extinction, which alarmed the scientific community. In this analysis, five major drivers of global biodiversity loss have been identified: climate crisis, pollution, changes in land use, overexploitation of resources, and invasive alien species.

The report reveals that the total number of alien species consists of 22% invertebrates, 14% vertebrates, 11% microbes, and 6% plants. It also stated that at least 218 invasive alien species account for more than 1,200 local extinctions. If this trend remains the same, the total number of alien species is expected to increase globally, and by the year 2050, it is estimated to be approximately 36% higher than in 2005.

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