Invasive alien species are among the top five causes of biodiversity loss worldwide. They rank with changes in land and sea use, overuse of organisms, climate change, and pollution. The new Kunming-Montreal Global Biodiversity Framework includes Target 6. This goal aims to reduce or control the negative effects of invasive alien species on biodiversity and ecosystem services.
Alien species, also known as non-native species, are organisms that humans bring into regions outside of their natural habitat. This can happen on purpose or by mistake. Some of these new species hurt the original biodiversity of the area, making them invasive alien species (IAS). The global movement of people and products is increasing. With more trade routes and improved transportation, more species are being brought into new environments.
Invasive Alien Species (IAS) have far-reaching consequences that extend beyond biodiversity, significantly impacting economic activities, livelihoods, food security, and the overall health and well-being of humans. These invasive species pose a considerable risk, undermining the progress towards achieving 10 out of the 17 UN Sustainable Development Goals (SDGs).
Key Terms
- Biological invasion refers to the act of transporting and introducing a species beyond its natural habitat. This can happen intentionally or accidentally due to human activities, which can lead to the species becoming established and spreading in the new regions.
- Native species are organisms, such as animals or plants, that exist within their natural range. This includes any shifting of range that happens without human involvement.
- Alien species is a term for a species whose presence in a certain region is due to human activities. These activities help the species bypass natural barriers and enter areas outside their normal range.
- Established alien species are a group of alien species that have successfully produced a self-sustaining population. They often spread in the new environment.
- Invasive alien species are a kind of established alien species that not only spread but also negatively affect biodiversity, local ecosystems, and other species. Many invasive alien species impact nature’s contributions to people, such as ecosystem goods and services, and our quality of life.
- Introduction pathways refer to the various methods by which species are relocated from one place to another because of human activities. This relocation can be either intentional or unintentional.
IPBES Report
According to a UN assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), invasive species pose a significant threat to Earth’s biodiversity and cost the world a staggering $423 billion annually.
This comprehensive assessment, conducted over four and a half years by 86 experts, including scientists and Indigenous communities, was approved by governments in September 2023 in Bonn. It highlights the urgent need to address the detrimental impact of invasive species on our planet’s ecological balance.
The latest findings build upon a 2019 report that issued a dire warning: 1 million species teeter on the edge of extinction. These precious life forms face threats from pollution, climate change, invasive species, direct exploitation, and land-use change. In fact, invasive species alone have led to 40% of all known animal extinctions.
Recognizing the urgency, governments have called for further research to deepen our understanding of this critical issue.
Remember This
- Invasive species like the water hyacinth, lantana, and black rat are highly disruptive.
- The water hyacinth is originally from tropical South America. Its growth clogs waterways and harms fish populations.
- Lantana is a type of invasive flowering shrub.
- Mosquito species such as Aedes albopictus and Aedes aegypti are invasive too. They are carriers of West Nile and Zika viruses.
- Most reports of invasive species are from the Americas, accounting for 34% of all reports.
- Europe and Central Asia come next with 31% of reports.
- 25% of reports originate from the Asia Pacific.
- Africa has the lowest count, with 7% of reports.
- Terrestrial ecosystems, especially woodlands and boreal forests, are mostly affected, with 75% of all reports.
- Costs linked to biological invasions have risen by 400% every decade since 1970.
- The financial toll of these invasions is predicted to keep rising in the future.
Invasive Alien Species Impacts
Invasive Alien Species Pose A Threat To Both People And Nature Across The Globe
- Over 37,000 alien species have been introduced worldwide due to human activities, with about 200 new species recorded each year.
- More than 3,500 of these species are considered invasive and have shown negative impacts.
- Different taxonomic groups show varying rates of invasive alien species, from 6% in plants to 22% in invertebrates.
- Islands report 20% of all impacts from invasive species.
- Terrestrial areas, especially temperate and boreal forests and cultivated land, report a higher number of negative impacts.
- A quarter of the negative impacts of invasive alien species are reported from aquatic areas, particularly from inland surface waters and shelf ecosystems.
- Roughly 16% of invasive alien species negatively affect nature’s contributions to people, and around 7% impact the quality of life.
Invasive Alien Species Cause Extinction Of Local Species
- Invasive alien species play a part in 60% of recorded global extinctions, and are the sole driver in 16% of such cases.
- Biotic homogenization, a significant downside of invasive alien species, leads to global biological communities becoming more alike, disrupting ecosystems’ structure and function.
- Changes in ecosystem properties, such as soil and water characteristics, constitute over a quarter of documented impacts.
- The level and nature of impacts differ based on the invasive species, ecosystems, and regions.
- Most global extinctions, attributed mainly to invasive alien species (90%), have happened on islands.
- Local extinctions make up 9% of documented impacts of invasive alien species on islands.
- Even places safeguarded for nature conservation or those that are remote are susceptible to the negative effects of invasive alien species.
Impact On The Economy, Food Security, Water Security And Human Health
- In 2019, the worldwide annual cost of biological invasions was over US$423 billion.
- The majority of these costs (92%) came from the negative impact of invasive species on the environment and human quality of life.
- Only 8% of these costs were related to managing the invasions.
- Despite some benefits, invasive species generally have harmful impacts, including on human health, livelihoods, water and food security.
- The most common impact, reported in over 66% of cases, is a reduction in food supply.
Invasive Alien Species Can Add To Marginalisation And Inequity
- Invasive alien diseases disproportionately impact Indigenous Peoples, local communities, ethnic minorities, migrants, and impoverished urban and rural communities.
- These biological invasions negatively influence the autonomy and cultural identity of these groups.
- Negative impacts include the loss of traditional livelihoods and knowledge.
- There is also reduced mobility and access to land due to these invasive species.
- Managing the invasive alien species also leads to an increase in labour.
Falling Short: Policies and Biological Invasion Management
- As of 2020, the world has only made limited progress towards global goals such as Aichi Biodiversity Target 9 and Sustainable Development Goal Target 15.8.
- Most countries have set targets for managing biological invasions in their national biodiversity strategies and action plans.
- Despite these targets, effective policies are often missing or poorly executed.
Future Predictions: Surge In Invasive Alien Species
- Invasive alien species are often intentionally introduced outside their natural range due to perceived benefits, but many have also been introduced unintentionally.
- These unintentional introductions frequently occur as contaminants in traded goods or as stowaways in shipments.
Economic Activities: The Indirect Drivers
- Indirect drivers, especially those related to economic activities and international trade, are increasingly enabling the transport and introduction of these species.
- These activities trigger the initial stages of biological invasions.
Impact Of Land And Sea Use Change And Climate Change
- Direct drivers like land and sea use change, along with climate change, are increasingly important in later stages of biological invasions.
- These drivers facilitate the establishment and spread of invasive alien species.
- Fragmented ecosystems are more susceptible to invasions.
Infrastructure Facilitating the Spread
- Transport and utility infrastructures can create corridors that aid the spread of invasive species.
- These infrastructures can even lead to the spread into remote, undisturbed, and protected areas.
Delayed Spread And Underestimation Of Impact
- Some invasive species spread immediately, while others begin to spread long after their first introduction.
- This delayed spread can lead to an underestimation of future impacts.
- A long period at low density might precede an increase in numbers for some invasive alien species.
- Changes in interactions with other species can trigger this increase, like the introduction of a missing dispersal agent or the removal of a competitor.
Recommendation
Management Of Biological Invasions
- There are many sources of accessible literature and information, tools, and novel and emerging technologies, including biotechnology, bioinformatics, eDNA, remote sensing and data analytics, for supporting the management of biological invasions.
- Successful management programs require sufficient and sustained resources.
- These resources are often lacking in developing countries.
- To improve public acceptance of new tools and technologies, engage multiple stakeholders including risk communication and context-specific application.
The Importance Of Prevention And Preparedness
- Prevention and preparedness are the most cost-effective strategies against invasive alien species.
- These strategies are crucial for managing threats from these species.
Prevention Strategies
- Prevention of biological invasions can be achieved through pathway management.
- Import controls, biosecurity measures before, on, and after the border, and measures to prevent escape from confinement are part of pathway management.
- Prevention is especially important in marine and connected water systems, where most attempts to eradicate or contain invasive species have largely failed.
- Prevention is highly effective on islands.
Preparedness Strategies
- Preparedness includes border surveillance, early detection, and rapid response planning.
- These measures are critical to reducing rates of establishment.
- Horizon scanning and risk analysis can help prioritise emerging invasive alien species.
Necessary Resources For Prevention
- Prevention measures demand sustained and adequate funding, capacity-building, technical and scientific cooperation, and technology transfer.
- Monitoring, relevant biosecurity legislation and enforcement, quarantine, and inspection facilities are also necessary.