Invasive species (IS) present one of the greatest threats to biodiversity in the EU, and globally, and will shortly be the subject of new legislative proposals to be published by the European Commission. More than 200 LIFE projects have directly or indirectly tackled this issue, achieving some outstanding results and providing important insights into where and how legislation can be effective.
Invasive species are organisms that are introduced accidently or deliberately into a natural environment in which they are not normally found. These species have been brought to Europe accidentally, or intentionally for use in the agricultural, silvicultural, horticultural or other sectors. The continuing growth in international trade and travel is contributing to a dangerous proliferation of IS.
The DAISIE project, supported under the EU's Sixth Research Framework Programme, has identified 12 046 non-native species present in Europe, of which 10-15% are expected to be invasive, with negative economic, human health or ecological impacts. A 2009 assessment estimated the cost of IS damage and control measures at some €12 billion per year in Europe; costs are likely to increase further as the number of IS continues to grow, the damage per IS increases and the effects of climate change take hold.
Whilst EU instruments exist to deal with other pressures on biodiversity, there is currently no comprehensive instrument at this level to tackle IS. EU policies and legislation covering nature, plant and animal health, water and trade regulations provide part of the solution but gaps remain in terms of both the species covered and their potential harmful effects.
At the end of 2008, the European Commission adopted a Communication (COM (2008) 789) presenting policy options for an EU Strategy on IS, which included the option of a dedicated legislative instrument. A more recent publication, "Our life insurance, our natural capital: an EU biodiversity strategy to 2020" (COM(2011)244), supported this approach and set specific targets for addressing IS at EU level.
The main objective of this new legislative instrument will be to minimise the negative impact of the worst IS on EU biodiversity, through a combination of measures designed to prevent invasive species entering and spreading within EU territory; for early detection and eradication of new IS; and for the control, containment or management of established IS in order to minimise negative impacts.
Since its launch in 1992, the LIFE programme has acted as a testing ground for actions aimed at tackling IS, and LIFE projects have demonstrated that the threats posed can be successfully addressed, particularly in isolated ecosystems, where invasive species often pose the greatest threat.
Prevention is the first line of defence in dealing with IS and LIFE projects have helped to develop knowledge in this area. One of the best examples comes from Belgium, where the 'AlterIAS' project (LIFE08 INF/B/000052) is working to reduce the introduction of invasive alien plants (IAPs), by raising awareness among stakeholders in the ornamental horticulture supply chain. Ornamental horticulture is the main pathway of plant invasion worldwide, and in Belgium almost all blacklisted plants have been introduced for ornamental purposes. The LIFE project aims to promote best practices for preventing the release and spread of IAPs through a Belgian voluntary code of conduct for such plants that it has developed in consultation with industry professionals, horticultural organisations and scientists.
As a general rule, eradication is only considered to be feasible in the early stages of invasion, when populations are small and localised, and only in areas of manageable size, such as small islands or other isolated ecosystems. This was the context of the 'Canna Seabirds' project (LIFE05 NAT/UK/000141), which succeeded in eradicating the brown rat (Rattus norvegicus) from the islands of Canna and Sanday (UK), thereby helping to improve the breeding success of resident seabirds such as the shag (Phalacrocorax aristotelis), razorbill (Alca torda) and puffin (Fratercula arctica).
Successful results were also achieved in Italy (LIFE97 NAT/IT/004153), where the black rat (Rattus rattus) was eradicated from the Tuscan Archipelago. In Portugal, 'Safe Island for Seabirds' (LIFE07 NAT/P/000649) is a project taking steps to eradicate rats and cats from the island of Corvo - the largest and most challenging exercise of this kind to be carried out in Europe to date. This project will oversee the first essential steps towards this goal, including the production of an operational plan for dealing with alien mammals, in collaboration with local stakeholders, and the testing of eradication techniques.
LIFE projects have also targeted the eradication of IAPs, often as part of a wider range of measures aimed at improving the conservation status of habitats. The 'Cuxhaven Coastal Heaths' project (LIFE05 NAT/D/000051), for example, succeeded in eradicating the black cherry (Prunus serotina) as part of a wider effort to improve the conservation status of coastal heaths and coppiced woodland in a Natura 2000 site near Cuxhaven (Germany). The project used Heck cattle, wild Konik horses and European bison to graze the target areas, which helped to eliminate the invasive black cherry, as well as controlling the spread of other woodland species, such as Crataegus sp. and Pinus sp.
In Hungary, the 'LIFE-SUMAR' (LIFE03 ENV/H/000280) was a project that succeeded in eradicating the false indigo bush (Amorpha fruticosa) as part of the restoration and sustainable management of the Vezseny Bend floodplain, an area of unique ecological significance, but where native forests and vegetation had been under threat from invasive species, especially false indigo bushes.
An Italian project, 'Bosco Fontana' (LIFE99 NAT/IT/006245) managed by the CNBFVR, National Center for Forestry Biodiversity of Verona, of the Italian Forest Service, targeted the IS American oak (Quercus rubra) and London plane (Platanus sp.). Removal of this IS helped improve the conservation status of the last remaining floodplain forest habitat in the Po basin. Project publications linked to CNBFVR can be downloaded on this page.
Containment or control, aimed at reducing the density, abundance or distribution range of IS, can be an appropriate strategy where eradication is no longer feasible. A good example of how this approach can be successful applied is the LIFE project 'Visón La Rioja' (LIFE00 NAT/E/007331), which sought to control the spread of the invasive American mink (Mustela vison) in the region of La Rioja (Spain), in order to improve the conservation of the native European mink (Mustela lutreola).
The project was part of a broader national Coordinated Action Plan, which also saw similar LIFE projects implemented in Catalonia (LIFE02 NAT/E/008604), Castilla y Leon (LIFE00 NAT/E/007299) and Alava (LIFE00 NAT/E/007335). The projects carried out regular culling campaigns of American mink and a network of experts, wardens and stakeholders was established to continue this work after-LIFE. Trapping schemes were also tested as a means of eradicating the American mink from certain areas. These activities proved successful in controlling the expansion of the species and in preventing it from entering the distribution area of the native European mink.
The LIFE cooperation project, ‘vertebrados invasores’ (LIFE02 NAT/CP/E/000014) included actions aimed at promoting the exchange of information between administrations of the islands of Portugal and Spain on the control of exotic vertebrates. This was done through the organisation of an international symposium, the production of a guide on management techniques for invasive vertebrates, and the establishment of a network to share information on IS and their management.
In Scandinavia, the 'MIRDINEC' project (LIFE09 NAT/SE/000344) is focusing on the control and containment of the raccoon dog (Nyctereutes procyonoides), a species native to eastern Asia, which has been listed as one of the 100 most damaging invasive species by the DAISIE project. The 'MIRDINEC' team will test new and innovative methods for culling and management of the raccoon dog to control the population in Finland, where it is already well-established and to prevent further dispersal.
Where IS are already well established and causing irreversible damage to native species, alternatives measures may need to be taken to safeguard genetic resources. The 'Espécies vegetais/Madeira' project (LIFE99 NAT/P/006431) successfully established a germplasm bank for the Madeira Islands. This contains representative samples of the genetic variability of native species that were under threat from IS and the loss of habitat. Some endemic species had already been driven to extinction, whilst others had been reduced to small populations, some of which were the only populations in existence.
LIFE is the main EU source of funding for field activities aimed at IS and the significant number of LIFE projects dedicated to this issue - some 40 projects targeting IS directly and some 200 indirectly - highlights the level of concern amongst conservationists in the EU. However, most of the interventions financed through LIFE are small scale and localised and even though they provide valuable lessons, a comprehensive strategy and legislative framework is now needed to effectively deal with the growing problem of IS in Europe.