Invasive alien species (IAS) are animals, plants or other organisms introduced by humans into places outside their natural range, where they become established, generating a negative impact upon native biodiversity, ecosystem services and human wellbeing.
IAS are among the most significant drivers of species extinction and ecosystem degradation, and are also a global threat to agriculture food security and human health and many other ecosystem services including economic activities and cultural integrity.
The huge scale of the socio-economic costs caused are poorly understood, but are estimated to be almost 5% of global GDP. Hawaii, which hosted the 2016 IUCN World Conservation Congress, is sadly at the forefront of alien species invasions. Of an estimated 1093 native endemic Hawaiian plants, 415 have been assessed for the IUCN Red List and 87% of these are classed as threatened due to impacts from IAS.
Unfortunately, the problem is getting worse with biological invasions on the increase due to ever increasing movement of people and goods around the world, and because of the synergistic effects of climate change. Although developed countries have borne the brunt of biological invasions to date, it is emerging economies with some of the world’s poorest communities and biodiversity rich areas that face the greater risk in the future.
If an introduced species becomes established and spreads, it can be very costly and difficult to eradicate and often mitigation of the impacts of the IAS is the only option. This makes prevention the most cost effective measure by far. This however, can be very challenging for countries with contiguous borders.
In 2010 almost all of the world’s governments adopted at the Convention on Biological Diversity COP 10 the Strategic Plan for Biodiversity 2011-2020, which included a commitment to address IAS (Aichi Target #9): “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”. This Strategic Plan has since been endorsed by other biodiversity related conventions and by the UN General Assembly.
In addition the importance of reducing the impacts of IAS to support sustainable development was reinforced in 2015 through the 2030 Agenda for Sustainable Development, which has a target (#15.8) specifically on IAS “By 2020, introduce measures to prevent the introduction and significantly reduce the impact of invasive alien species on land and water ecosystems and control or eradicate the priority species”
There has been some progress with meeting these targets, but it is far from adequate. While governments, NGOs and communities are increasingly taking steps to eradicate and control IAS, preventative measures have been taken in only a limited number of countries. As a consequence, the overall rate of invasions, with great economic and ecological costs, shows no sign of slowing. In fact, only 3% of countries are currently on track to meet these international commitments.
Most countries, and in particular those in the developing world, have limited capacity to act and are likely to suffer high environmental, social and economic impacts as a result. Therefore they need urgent support in developing measures to prevent future invasions and manage existing ones.
In Hawaii it is resoundingly clear that the indigenous people, the Native Hawaiians, have a deep understanding and relationship with the ʻāina--the land and sea, the natural environment and species--that stretches back more than a thousand years, and continues today. The arrival and proliferation of invasive alien species is disrupting this relationship. It is therefore essential that local communities and indigenous people are involved in the efforts to address IAS, in particular empowering First Nation’s People by recognizing their traditional ecological knowledge in legislation, to inform decision making, participation, policy, evaluation and outcomes of the management of invasive species.
There is, therefore, an urgent need to take the bold, yet practical, measures necessary to safeguard biodiversity and human wellbeing from the devastating impacts of invasive alien species.