What's wrong with alien species in Europe?

Invasive alien species are known to have a high impact on European biodiversity, as well as on human activities and health, and their sound management offers one of the few concrete examples of effective measures able to reduce biodiversity loss. Nevertheless, due to a lack of information and awareness, the issue of IAS and their impact has been often underestimated and adequate prevention and mitigation measures are thus lacking. To overcome such problems, also in support of the new coming EU legislation on invasive alien species (IAS), the European Environment Agency (EEA) has published two reports focusing on IAS impact and relevant indicators:

• The impacts of invasive alien species in Europe
• Invasive alien species indicators in Europe - a review of Streamlining European Biodiversity (SEBI) Indicator 10

Both reports have been realised by a multinational team of experts in collaboration with the IUCN/SSC Invasive Species Specialist Group (ISSG), in the context of the continued support provided to the European Commission in its efforts to develop an EU legislative instrument to deal with the problem of biological invasions.

The report on “The impacts of invasive alien species in Europe” includes a description of the multifaceted impact of 28 alien species selected among those known to cause significant harm to biological diversity, socioeconomic values and human health in Europe. In fact, in recent times the true extent of the pervasive threat posed by IAS in both terms of ecological and socio-economic impacts has become much better understood. Scientific researches focusing on the impact of IAS on the environment and human wellbeing have been recently published, including many detailed technical reports made ad hoc for the European Commission.

The report is organised on the basis of the different types of impact by IAS which are gathered together in 14 categories. Such categories include competition, predation and transmission of diseases between alien and native species, as well as the various ecosystem services affected. Indeed some IAS might have an impact on a specific ecosystem service, or may affect multiple ones. There are also IAS acting as vector of disease and affecting human health, as well as IAS making extensive damage to infrastructures, landscape, and agriculture. The species selected as example encompass a diverse range of groups that threaten European freshwater, brackish water, marine and terrestrial environments. Such species have been selected because of the significant harm they pose to biological diversity, but given the extent of the problem it is clear that the both lists of species and impacts are not intended to be comprehensive and exhaustive, but only representative of a very complex situation.

Rose-ringed parakeet in Versailles © Photo: Riccardo Scalera

Also the report “Invasive alien species indicators in Europe - a review of Streamlining European Biodiversity (SEBI) Indicator 10” by showing patterns and trends of biological invasions, aims at contributing to raising public awareness of the biological, ecological and socio-economic impacts of IAS. This report was commissioned by the EEA to support the “Streamlining European 2010 Biodiversity Indicators” (SEBI 2010) process, and particularly to revisit and further develop the indicator “Invasive alien species in Europe”. The aim was to critically review and improve this indicator, and propose an updated methodology. Further, options for methodologies of new indicators, which monitor IAS over time across Europe, are discussed. Particular attention is given to closely linking the proposed indicators to the recent biodiversity policy goals and developments. In fact  since indicators reflect trends in the state of the environment and monitor the progress made in achieving environmental policy targets, they have become indispensable to policy-makers. Moreover, indicators enable and promote information exchange regarding the issue, thus communication is their main function. 

Thus, both reports should contribute to support raising awareness and communicating the impact of IAS to all stakeholders as well as the general public by reporting the best scientific knowledge on the issue. Besides, the biodiversity strategy needs to be aligned to the biodiversity knowledge base to underpin policy with up-to-date scientific data and information. The new EEA reports are thus aimed at raising awareness and informing on the environmental and socioeconomic impact of IAS, not only all stakeholders and the general public but also decision makers and policy makers. In this context the report is fully in line with the EEA's mandate “To help the Community and member countries make informed decisions about improving the environment”.

A new code for preventing animal escapes from zoos

Himalayan porcupines and Egyptian fruit bats do not belong to the European fauna, yet a few years ago they were well established in the wild, respectively in Devon (UK) and in the Canary islands. Wildlife managers decided to remove them to mitigate their impact on the new environment. Nevertheless, the problem could be easily prevented, because the introduction of the two species was probably a consequence of zoo escapes.

Specific and comprehensive analysis regarding invasive alien species (IAS) originated by escapes and/or releases from zoological gardens and aquaria in Europe are lacking, but there are evidences of some IAS populations still thriving and clearly originating from such pathways (even though in terms of relative risk, zoos and aquaria have a limited responsibility compared to other pathways i.e. pet trade, hunting, horticulture, etc.). A famous case is the one of the ruddy duck, a species of North American origin, which represents a major threat to the European white-headed duck, and is now being targeted by costly management programs. Another famous “escape” is the one of the tropical alga Caulerpa taxifolia unintentionally introduced from a public aquarium into the Mediterranean Sea. There is also an episode regarding the transmission of disease, like in the case of the deadly amphibian fungus Batrachochytrium dendrobatidis (Bd) accidentally introduced within the endangered population of the Mallorcan midwife toad (although before Bd was identified as a pathogen, and relevant screening methods were established). Surprisingly, there are also several records of marine mammals (including even beluga whales and sea lions) introduced from coastal dolphinaria and oceanaria, particularly in the Black Sea.

In Poland the Canada goose was unintentionally introduced also through escapes from a local zoo. Photo © Vibe Kjaedegaard

The identification of pathways and the implementation of best practices and voluntary measures to prevent the threats posed by IAS are currently recognised as critical issues in relation to the European policy on IAS. On the other hand, modern zoos are privileged allies of conservationists for the fundamental role they play on biodiversity conservation programs and related awareness raising activities (it is estimated that over 140 million people visit European zoos every year). For this reason, the Bern Convention and the Invasive Species Specialist Group (ISSG) of the IUCN, in collaboration with the European Association of Zoos and Aquaria (EAZA) have developed the European Code of Conduct for Zoological Gardens and Aquaria on Invasive Alien Species.

The publication in English (link updated on 27/11/2016)

The objective of this document is to provide guidance to zoological gardens and aquaria to strengthen their role for biodiversity conservation in Europe, by contributing to mitigate the problems related to the spread of IAS. This should be done through the following measures:

• Prevent the introduction and spread of IAS and related pathogens and diseases;
• Promote the need to raise awareness on biological invasions;
• Support IAS related research projects and other relevant conservation initiatives.

In line with the Convention on Biological Diversity (CBD) targets for 2020, as well as the EU biodiversity strategy to 2020, the code includes five main recommendations:

1. Adopt effective preventative measures to avoid unintentional introduction and spread of IAS;
2. Take into account the risks of IAS introductions in all wildlife and habitat management projects;
3. Proactively engage in awareness raising and outreach activities focusing on IAS and their impacts;
4. Adopt best practices for supporting early warning and rapid response system for IAS;
5. Be aware of all relevant regulations concerning zoological gardens and aquaria and IAS

The code - which includes a description of measure to implement the five recommendations above - has been formally approved at the last Standing Committee meeting of the Bern Convention on 30 November 2012. At the same meeting, with the aim of ensuring responsible and proactive policies and applying these in a coherent manner across Europe, the Standing Committee praised the innovative approach of such voluntary instrument, and adopted the Recommendation No.161 (2012). The aim is to invite all Bern Convention parties to implement the code, by drawing up their own national codes of conduct based on the European version, and by collaborating with zoological gardens and aquaria in implementing good practices aimed at preventing the spread of invasive alien species.

Another major achievement of the new code has been the formal acknowledgement received by the recent 11th Conference of the Parties of the CBD held at Hyderabad (India, 8-19 October 2012) which in its Decision XI/28. Invasive alien species:

“welcomes the development of voluntary codes of conduct on these separate pathways, such as the “Code of conduct on zoological gardens and aquaria and invasive species” developed by the Bern Convention, the IUCN Invasive Species Specialist Group and the European Association of Zoos and Aquaria, and requests the Executive Secretary to compile information and to work with experts to avoid and/or minimize the risks particular to these separate pathways”

Shutting the stable door before the horse bolts.
Drawing © Riccardo Scalera