Résumé en anglais.

Recent decades have seen significant changes in the biota of the Mediterranean and the Black Sea due to the introduction of non-indigenous species. Reliable scientific data on the dynamics of their distribution and abundance are essential to understand their ecological and economic effects. This review – in addition to providing images and descriptions of relevant species to aid in identification – presents a unique historical and regional perspective on these species’ impacts, based on many years’ worth of research. The Black Sea’s primary invaders come from the Mediterranean. Species like the comb jelly Mnemiopsis leidyi have caused major declines in biodiversity in the region by crippling key segments of the food chain. Similar results have been noted in the Marmara Sea, a crucial water exchange point located between the Aegean Sea and the Black Sea. Infiltration into the Mediterranean comes from both the east and west – with Lessepsian species passing through the Suez Canal and fish and invertebrate species originating from the Atlantic expanding their ranges. As of the publication of this review, over 900 non-indigenous species have been reported in the Mediterranean and almost 300 in the Black Sea, with these numbers expected to rise in the future. Numerous Lessepsian fishes are commercially relevant and have been absorbed into local markets, particularly in the eastern Mediterranean region. While these species are targeted through various fishing techniques, many others are simply discarded due to a lack of value and there are even some, such as lionfishes, pufferfishes and several species of jellyfishes, that present immediate dangers to human health. Stewardship of native species, regional cooperation on the enforcement of legal measures, increased public awareness and the creation of marine protected areas are thus essential to minimize and reduce the impacts of non-indigenous species both in the Mediterranean and the Black Sea.

Maritime canals dissolve natural barriers to the dispersal of marine organisms, providing novel opportunities for natural dispersal, as well as for shipping-mediated transport. This book is the first to assess the impacts of the world’s three principal maritime canals – the Kiel, the Panama, the Suez – as invasion corridors for alien biota. These three canals differ in their hydrological regimes, the types of biotas they connect, and in their permeability to invasions.

The global scale of alien species invasions is becoming more and more evident in the beginning ofthe new millennium. Though the problem ofbiological invasions became a rapidly growing research area, there are large gaps still, both geographically and the matically, to be filled in the near future. This book is the first attempt to provide an overall picture of aquatic species invasions in Europe. Its geographical scope stretches from Irish waters in the west to Volga River and the Caspian Sea in the east, and from Mediterranean in the south up to the Arctic coast of Europe. Not all parts of the continent could be equally covered, as in some countries species invasions are not studied yet. The book tends to represent the array of all major European aquatic systems on the broadest geographical and ecological scope possible from fully saline seas, semi-enclosed brackish water bodies and coastallagoons to freshwater lakes, major river systems and waterways. The key objectives include the present status and impacts caused by non-native aquatic species in European waters. Please note that lengthy species lists submitted for publication and additional informa tion were put on the Internet, as the electronical version of these tables benefits from computer assisted search for data (http://www. ku. lt/nemo/EuroAquaInvaders. htm). Altogether more than 100 scientists from 24 countries have joined to synthesize the available information on bioinvasions. However, the book does not claim to be fully comprehensive.