GSPC Target 10

Introduction

Invasive alien species (IAS) are species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity.

IAS occur in all taxonomic groups, including animals, plants, fungi and microorganisms, and can affect all types of ecosystems. While only a small percentage of organisms transported to new environments become invasive, the negative impacts can be extensive and over time, these additions become substantial.

Invasive species have been shown by the Millennium Ecosystem Assessment to be a major agent of ecosystem degradation as they affect not only plants and plant populations, but they are detrimental to vital plant associations and habitats, reducing ecosystem services and values to people.

Invasive species also pose a significant threat to global economic health with estimated costs of US$350 billion annually.

Most developed countries have controls on the introduction of potentially invasive species and procedures for risk assessment of intentional introductions, especially those with government agencies devoted to biosecurity. This is less true in many developing countries where awareness of the threat of invasive species is more limited and the capacity to prevent and manage invasions is often inadequate.

Climate change is predicted to enhance the spread and impact of many existing invasive species, as well as potentially providing suitable conditions for presently non-invasive species to become invasive.

The removal of invasive alien species is a key management activity for effective conservation. However experience has shown that preventing new invasions of harmful species is more cost-effective than waiting until they have become a threat. Applying preventative measures requires action at both international and national levels including the coordination of agencies working in the areas of plant health, transport, trade, tourism, protected areas, wildlife management and water supply.

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Learn more

Alien species that become invasive are considered to be a main direct driver of biodiversity loss across the globe. In addition, alien species have been estimated to cost our economies hundreds of billions of dollars each year.

A species introduction is usually vectored by human transportation and trade. If a species’ new habitat is similar enough to its native range, it may survive and reproduce. For a species to become invasive, it must successfully out-compete native organisms, spread through its new environment, increase in population density and harm ecosystems in its introduced range.

Common characteristics of IAS include rapid reproduction and growth, high dispersal ability, phenotypic plasticity (ability to adapt physiologically to new conditions), and ability to survive on various food types and in a wide range of environmental conditions. A good predictor of invasiveness is whether a species has successfully or unsuccessfully invaded elsewhere.

Invasive alien species can be particularly problematic for islands. The geographic isolation of islands limits immigration of new species, allowing established species to evolve with few strong competitors and predators. Islands therefore have a high proportion of endemic and specialized flora and fauna. They are more prone to invasion by alien species because of the lack of natural competitors and predators. In addition, islands often have ecological niches that have not been filled because of the distance from colonizing populations, also increasing the probability of successful invasions.

The CBD website provides further details about invasive species in general, as well as their specific impact on islands.

Implementation of this target contributes to Target 9 of the Aichi targets of the Strategic Plan for Biodiversity 2011-2020:

T9: By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated, and measures are in place to manage pathways to prevent their introduction and establishment.

Implementation

This target addresses biological invasion as a phenomenon, and does not just focus on the invasive species themselves.

It combines both the prevention of invasion by alien species (animal, plant, micro-organism) and the management of ecosystems and habitats into which they have already been introduced.

Land management plans (especially for areas designated as important for plant diversity - see target 5) need to be designed (using the ecosystem approach) to address the damage done to plant species and /or their communities and to restore ecosystem functions, goods and services.

The Conference of the Parties (COP) to the Convention on Biological Diversity (CBD) has recognized that there is an urgent need to address the impact of invasive alien species (IAS), and established IAS as a cross-cutting issue at its fourth meeting. The decision of COP 6 included adoption of Guiding Principles for the Prevention, Introduction and Mitigation of Impacts of Alien Species that Threaten Ecosystems, Habitats or Species.

There is a need to build capacity for the development and enhancement of early warning, early detection and biosecurity/biosafety systems for invasive species, including in collaboration with the International Plant Protection Convention and regional and national phytosanitary services.

There is also a need to recognise that it is economically sound to invest in prevention and early detection and removal where possible, instead of having to deal with control and eradication of invasives.

Tools and resources

Please also check in the database of Tools of Resources for Case Studies relevant to this target.

Status

Invasive Alien Species (IAS) can be plants, animals or organisms whose introduction and/or spread outside their natural, past or present distribution threaten the existing biological diversity (CBD 2009). Implementation of this target is closely linked to Aichi Target 9 (Invasive alien species prevented and controlled) and Target 11 (Protected areas are effectively and equitably managed).

On going projects

At the international level, CABI has been involved with many projects attempting to prevent the spread of invasive alien species world wide. This includes preparing publications, infographics, short films, as well as on-the-ground fieldwork.

CABI also curates the Invasive species compendium, an online database containing comprehensive information for those working with invasive alien species. (http://www.cabi.org/isc)

The International Plant Sentinel Network (IPSN) is part of a 3 year EUPHRESCO project which involves collaboration from a number of partners across Europe; the aim is to develop an Early Warning System for potentially invasive pests and diseases, building on models such as New Zealand's 'Expat Plants' project (www.plantsentinel.org/).

Other useful information

The Global Invasive Alien Species Information Partnership (GIASI Partnership) was established to assist Parties to the Convention on Biological Diversity, in implementation of Aichi Biodiversity Target 9 and CBD Article 8 which focuses specifically on the prevention and eradication of Invasive alien species. http://giasipartnership.myspecies.info/

In Europe DAISE (Delivering Alien Invasive Species Inventories for Europe) provides an up to date list of all important IAS.

Other significant initiatives include the Honolulu Challenge, launched at the 2016 IUCN World Conservation Congress in response to a call for more action on invasive alien species. It challenges countries and organizations to commit to taking bold yet practical measures necessary to safeguard biodiversity and human well-being from the devastating impacts of invasive alien species and has gathered commitments from governments and organizations to meet the aim of the Honolulu Challenge.

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