NEW DELHI: A new report shows that a number of invasive alien plants and animal species have been invading at unprecedented rates causing serious biodiversity and economic threats. Moreover, it is impacting the well-being of indigenous communities, who depend on nature and play a key role in the extinction of many native plants, animals and microbes.
Due to an increase in global trade and human travel, the annual costs of invasive alien species have at least quadrupled every decade since 1970. It has been estimated that the annual cost exceeds USD 423 billion.
The alien species which include plants, shrubs, microbes and others have been introduced to new regions through human activities. These alien species affect the growth of native species affecting ecosystem function, goods and services.
For instance, In Kerala, the Caribbean false mussel (Mytilopsissallei) has wiped out native clams and oysters which are important for local fisheries.
Mytilopsissallei was originally from the Atlantic and Pacific coasts of South and Central America. Researchers believe that it may have travelled to India via ships, later spreading to estuaries through smaller fishing vessels that travel frequently between coastal oceanic waters and the fishing harbours of Kerala. It may have triggered the spread of the ‘VarathanKakka’ (‘alien bivalve mollusc’ in Malayalam) across the State by carrying it into new waters.
The report Assessment Report on Invasive Alien Species and their Control says not all alien species become invasive but a significant proportion do become invasive alien species. The report was prepared by representatives of the 143 member States of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES).
According to a report, about 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.
Many invasive alien species have been intentionally introduced for their perceived benefits, without consideration or knowledge of their negative impacts in forestry, agriculture, horticulture, aquaculture, or as pets. There are some species unintentionally introduced through trade routes and contaminants.
The report recorded that there are 37,000 alien species, including more than 3,500 invasive alien species, have been recorded around the world. These invasive alien species have played a key role in 60% of global plant and animal extinctions recorded.
The report pointed out that Water hyacinth (Pontederia crassipes) is the world’s most widespread invasive alien species on land. Lantana (Lantana camara), a flowering shrub, and the black rat (Rattus rattus) are the second and third most widespread globally.
More than 2,300 invasive alien species are found on lands managed, used and owned by Indigenous Peoples across all regions of Earth.
The report says invasive alien species threaten indigenous people’s quality of life. The native species connect to their emotions and fulfil their daily needs. The invasive species often leads to general feelings of despair, sadness and stress.
Moreover, biological invasions negatively affect the autonomy, rights and cultural identities of Indigenous Peoples and local communities through the loss of traditional livelihoods and knowledge, reduced mobility and access to land, and increased labour to manage the invasive alien species.