"Union gives strength” against biological invasions

The European Union has just approved an ambitious COST project addressing the threat of biological invasion in the region. The project, which is aimed at the development of a European information system for alien species, is basically built on DAISIE, a previous EU funded project that so far delivered the most comprehensive inventory of alien species in Europe. Aesop’s famous quotation "Union gives strength” is definitely the motto which does better express the great success achieved by DAISIE: in fact this FP6 project could count on the fruitful collaboration of a large number of experts in the field of biological invasions. Similarly, the new COST initiative gathers together an international team of nearly 100 leading experts from over 30 countries, led by NERC Centre for Ecology & Hydrology in the UK.

DAISIE (Delivering Alien Invasive Species Inventories for Europe) was indeed the first attempt to assess the extent of the problem of biological invasions at the European level. The collection and analysis of data relative to over 10.000 alien species recorded in the region allowed to fill in the main knowledge gaps on the issue, including the identification of key patterns. The results showed that the rate of invasion of alien species has been increasing in recent years, and so are the associated costs to society, the economy and biological diversity (including the many impacts on the goods and services provided by ecosystems). They also showed that a unitary regional approach is required to design and implement innovative and cost effective solutions to combat IAS and the problems they cause.

DAISIE portal (www.europe-aliens.org)

Nevertheless the information on alien species across Europe is still scattered in a multitude of databases, plus a number of peer-reviewed articles and grey literature, unpublished research projects or institutional datasets. In fact many other initiatives exist that have contributed to consolidate information into centralised regional or local databases (examples are NOBANIS, REABIC, ESENIAS, MAMIAS, the Baltic Sea alien species database). The problem is that the available databases are severely affected by many constraints that limit their effective use, e.g. data obsolescence, lack of interoperability and uncertainties for long-term sustainability, etc. Besides, there are major differences in their geographic, taxonomic and ecological coverage.

In this context, and in continuity to DAISIE, the new project aims at facilitating enhanced knowledge gathering and sharing. In fact a key task of the new COST project will be the exploration of the existing data gaps to ensure a better harmonisation and validation of information distributed in the available resources, to be efficiently used in early warning system decision tools (through standards developed in DAISIE). The ultimate aim is to support the development of a European information system for effective and informed decision-making in relation to IAS and the relevant EU legislation that is being developed. COST, which is an intergovernmental framework for European Cooperation in Science and Technology, will ensure the project partners to work in close contact with all national and regional alien species networks to ensure a fair exchange of high quality and reliable data and information. The objectives also focus on the need to analyse data and information to assess the impact of invasive alien species and the relevant pathways – thus fully supporting the implementation of the EU 2020 Biodiversity Strategy.

The web-page of the Action can be found at http://www.cost.eu/TD1209

Does this snail look sufficiently "alien"?

The European Commission has recently issued a decision according to which the so called apple snails shall not be imported into or spread within the European Union (see Implementing Decision of 8 November 2012).

The new legal provision targets any organisms of the genus Pomacea, and regulates the introduction into and the movement within the region of all plants that might represent an effective pathway for such freshwater snails e.g. all plant species for planting that can only grow in water or soil that is permanently saturated with water.

Apple snail Pomacea canaliculata © Riccardo Scalera 

The apple snails are mollusks characterised by a very large shell, which may reach the size of an apple as the name suggests. They are native to South America and have been introduced in many countries of the world, particularly in North America and Asia, both intentionally or accidentally as a consequence of the food and the aquarium trade (see for example the case of Pomacea canaliculata as reported by the GISD). In Europe the only known record of occurrence of apple snails is in Spain. 

In fact the EC decision come in response to a risk assessment analysis made by the European Food Safety Authority (EFSA) and the Spanish authorities, following the discovery of the presence of the apple snail (Pomacea insularum) in the Ebro delta, where it has been causing damage to rice production and the natural environment. According to the risk analysis (PRA), a legislative ban on import of the entire genus Pomacea was the only risk reduction option identified that could reduce the probability of entry of this potentially invasive alien species. Besides, the PRA established that: a) the potential consequences of the organism for rice crops are major; b) the probability for establishment of the organism is very likely and c) the probability of spread is estimated as likely. Thus, while rice fields and natural wetlands are known to be at risk, many other aquatic environments could also be threatened, due to the snail's voracious appetite for water plants and the fact that it can survive in a wide range of climatic conditions.

The objective of the legal provision is to prevent the further release of the snail into the environment, either intentionally or accidentally. In fact, in the absence of less restrictive measures efficiently combating the threat posed by that organism there is a high risk of spreading of this freshwater snail to fields and watercourses, lakes, ponds and swamps. The provision does not focuses only on Pomacea insularum (the species reported in Spain) because other species might be available in the market to replace it, and in any case many other species from the complex are almost indistinguishable.

The decision also requires Member States to adapt their legislation in order to comply with the specified rules, including the establishment of demarcated areas in cases where the genus Pomacea is found to be present in fields and watercourses. In principle this should be a first step to eradicate the organisms concerned, to raise awareness as appropriate and to ensure intensive monitoring for their presence. Wherever necessary Member States should carry out annual surveys in areas where the specific organisms are likely to be found, e.g. rice fields, and notify the results accordingly (even though the presence of the snail is only suspected). In the meantime in Spain, as reported by EPPO, an action plan was implemented to control and eradicate the apple snail. The main measures included phytosanitary and disinfection treatments, removal of adults and eggs, physical barriers, and surveys.

Europe keeps investing in invasive alien species

Over 7 million euro are now available for projects aiming at increasing knowledge and understanding on biological invasions, as well as alien species impact in relation to both public perception and climate and other environmental changes. These are the themes specifically addressed by the new BiodivERsA 2012-2013 Pan-European call for research proposals specifically dedicated to "Invasive Species and Biological Invasions". The deadline for mandatory pre-registration is 14th of December 2012.

The European partners in the BiodivERsA network have already joined important efforts to organize and fund a pan-European call for research projects on invasive alien species (IAS) and biological invasions in the past. For example, within the 2008 joint call the BiodivERsA partners had funded the project RACE - Risk Assessment of Chytridiomycosis to European Amphibian Biodiversity. This project focuses on Chytridiomycosis, an amphibian disease responsible of causing die-offs and even extinctions of many amphibian populations around the world. The disease is caused by Batrachochytrium dendrobatidis (also called Bd for short), a fungus that for this reason is also considered one of the 100 World’s Worst Invasive Alien Species by the IUCN/SSC Invasive Species Specialist Group. In this context RACE aims at assessing the risk that Bd poses to European amphibians and at developing tools and protocols to enable surveillance of Bd across Europe. RACE also aims at improving the understanding where in situ mitigation and captive-breeding conservation efforts are most necessary to preserve European amphibian biodiversity. The findings should then be formalised into a European Threat Abatement Plan (ETAP).

African clawed frogs, a potential vector of Bd. Photo © Riccardo Scalera

Many research projects focusing on invasive alien species have been financed so far in Europe under the auspices of the various Framework Programmes (a scheme which also BiodivERsA belongs to). For example, according to the result of a specific study published on Biological Invasion journal, focusing on the period 1994-2006, the EC has funded a total of 90 research projects dealing with IAS, for a total budget of more than 88 million euro. Of these, 70 projects focused entirely on IAS and the other 20 had only a part of the activities related to this issue. That is a very important contribution to face the threat of biological invasions despite the lack of either a specific strategy or a dedicated financial instrument in the EU. Beside, this response complies with the priorities of the Sixth Environment Action Programme of the European Community for 2002-2012, and shows that concrete steps are being undertaken in the right direction to support the European Commission’s policy according to which IAS are recognised as a key pressure on biodiversity and a priority for action.

Invasives creeping out of place

To find the first and only "original" remains of a snake in the Canary islands, in the Atlantic sea, we need to go back to the late Miocene, a geological epoch especially renowned for the repeated desiccations of the Mediterranean sea. Paleontologists have found just one vertebra of what was something like a boa living in the archipelago 5-10 million years ago. As far as we know, since then no snakes lived in the Canary islands, at least until the early 2000, when the archipelago has experienced the very unfortunate introduction of the California kingsnake (Lampropeltis californiae). This species, probably escaped or released from captive facilities, is now an important environmental problem in the archipelago due to the enormous social alarm among the population not accustomed to the presence of snakes, and the damage caused to many endemic reptile species, such as the Gran Canaria giant lizard (Gallotia stehlini). To remove this major ecological threat, over 1000 snakes were captured since 2007, and now thanks to the 1 million euro Lampropeltis project supported by the EU through the LIFE+ programme, the authorities expect to set up the conditions for the eradication of the species.

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California kingsnake (striped albino pattern). Photo © Ramón Gallo Barneto

The lucrative trade of species for pet amateurs carries the inherent risk of escape or abandonment of animals kept in captivity, and as a consequence the potential establishment of wild self-sustaining populations of a number of invasive alien species. In fact the California kingsnake is only one of the many species known to have succeeded in getting naturalized outside their native range as a side effect of the pet industry. Another major example among the snakes is the Burmese python (Python molurus bivittatus) in the Everglades, Florida. The spread of this species is a major concern in the region, because it is a predator that can grow over 5 metres long, and as such is able to eat nearly any native animal, possibly even panthers and alligators.

Snakes are often introduced also as cargo stowaway. In this way many species manage to colonise even remote oceanic islands, where they can represent a serious threat to some of the most and unique living creatures of the world. A renowned case of accidental introduction concerns the brown tree snake (Boiga irregularis). Soon after World War II this native of the Solomon islands, northern Australia and Papua New Guinea, was transported as stowaway by military cargos to the island of Guam, Mariana Islands. In this western Pacific island this ecologically disrupting predator is having a dramatic ecological and economic impact. In particular is negatively affecting several species beside having killed off at least 8 of the island’s 11 species of native birds, as well as some indigenous lizards and bats. Now there is a growing concern that the species could take advantage of the frequent aircraft flights from Guam to the Hawaii and make its way to this archipelago in central Pacific, where its ecological and economic impact would be even greater (according to some studies it might cost over 1.7 billion dollar per year if successfully introduced).

Brown Tree Snake. Photo © Daniel O'Brien

Accidental introductions linked to military activities are likely to have occurred also in ancient times: perhaps snakes were used to frighten enemies even during Roman assaults. As suggested for the origin of the viperine snake (Natrix maura) in the Balearic, Spain, some introduced populations of snakes in the Mediterranean islands could be actually linked to such battle related events. Also this snake is having a major ecological impact in terms of loss of indigenous species, and changes in community structures and function. In fact in the Balearic Islands, the introduced viperine snake is known to represent a serious threat for the endangered endemic Mallorcan midwife toad or ferreret (Alytes muletensis) in Mallorca, and was probably involved in the extinction of the species in Menorca.

Other than inflicting ecological harm, non-indigenous snakes can be dangerous to humans, as some species are also poisonous. A typical poisonous snake introduced outside its natural range is the habu (Trimeresurus flavoviridis), a Japanese native viperid introduced in Minnajima, Okinawa Island. Also the brown tree snakes is well known for its venomous bites: in Guam the estimated cost for hospitalisation and intensive care for people affected by snakebite (especially infants) is about 25,000 dollars per year. Along with the ecological damages and the health problems, the brown tree snake can also provoke significant economic impacts, like frequent power outages and damage to the electric lines due to the attitude to crawl along the wires: yearly cost for direct damages and lost productivity is conservatively estimated at 1 million dollars.

Thus, nothing to do with the notorious old rumor, still very popular in countries like Italy, according to which snakes, and particularly vipers, are recurringly broadcasted by helicopters - by either environmentalists or parks authorities - to restore their wild populations. Here the problem for nature conservation professionals is how to prevent the further release or spread of snakes and other harmful alien species outside their natural range, where they clearly represent a key driver of biodiversity loss.