The European Alien Species Information Network (EASIN; http://easin.jrc.ec.europa.eu) aims to facilitate the exploration of existing alien species information from distributed sources through a network of interoperable web services, and to assist the implementation of European policies on biological invasions. The network allows extraction of alien species information from online information systems for all species included in the EASIN catalogue. This catalogue was based on an inventory of reported alien species in Europe that was produced by reviewing and standardizing information from 43 online databases. It includes information on taxonomy, synonyms, common names, pathways of introduction, native range in Europe, and impact. EASIN catalogue entails the basic information needed to efficiently link to existing online databases and retrieve spatial information for alien species distribution in Europe. Using search functionality powered by a widget framework, it is possible to make a tailored selection of a subgroup of species based on various criteria (e.g., environment, taxonomy, pathways). Distribution maps of the selected species can be produced dynamically and downloaded by the user. The EASIN web tools and services follow internationally recognized standards and protocols, and can be utilized freely and independently by any website, while ownership of the data remains with its source, which is properly cited and linked.

Numerous colonies of the invasive colonial ascidian Didemnum vexillum Kott, 2002 have been found in the Lagoon of Venice (Italy) in 2012, overgrowing fouling organisms on maritime structures such as docks, pilings, and pontoons. This is the first record for the Mediterranean Sea. A survey conducted in July 2012 revealed that D. vexillum is present in the euhaline and tidally well flushed zones of the lagoon, whereas it was absent at the examined estuarine tracts and at the zones surrounding the saltmarshes. Suitable climatic, physiographic and saline features together with a high volume of international maritime traffic make the Lagoon of Venice a perfect hub for the successful introduction of temperate non-native species.

The freshwater planktonic calanoid copepod Skistodiaptomus pallidus (Herrick, 1879), native to cold and temperate latitudes in the United States, has recently been identified as having non-indigenous populations in Western Europe and New Zealand. A further non-indigenous population of this species is recorded here from a large inland reservoir in the State of Sinaloa, northwestern Mexico. This copepod species can be distinguished from its congeners mainly by its pincer-like distal process of the second exopodal segment of the right fifth leg of the male. This is the first record of S. pallidus in tropical latitudes and its presence in Mexico is far outside of its known intra-continental range. This introduction is attributed to human agency and deemed as a recent arrival. The local fisheries and aquaculture activities in the surveyed reservoir are the most probable vectors of this introduction but avian transportation by migrating pelicans is also possible. Because of the competitive abilities of this species and the connectivity of this reservoir, it is expected that S. pallidus will spread to other man-made locations in Mexico.

Ponto-Caspian amphipods have continuously been invading the Rhine system at least since the last quarter of the 20th century. This pilot study attempts to identify current regional invasion fronts of invasive amphipods for future continuous monitoring. A standardized kick and sweep sampling technique was used to collect amphipods between July 2011 and May 2012 at five sites in the Northern Upper and Middle Rhine and 35 sampling sites within the following tributaries: Ahr, Lahn, Nahe, Schwarzbach and Weschnitz. Invasive Dikerogammarus villosus dominated sites in the Middle Rhine, and Echinogammarus ischnus in the Upper Rhine. Gammarus roeseli was dominant in the middle and upper reaches of the tributaries, co-occurring with Gammarus pulex in the lower reaches, while G. fossarum was found exclusively in head stream regions. The invasive amphipod species, however, did not invade the majority of the tributaries. D. villosus was only found in the River Lahn, and Chelicorophium robustum, another invasive species, at the confluence of the Nahe and the Rhine. Thus, we identified two kinds of invasion fronts: (1) invasion fronts at the tributaries’ river mouths, with a distinct change in faunal compositions over short distances and invasive species occurring only in the most downstream portion of the tributaries. These fronts appear to have been stable over the last decades despite dramatic species turnover within the Rhine itself. (2) A second kind of invasion front was in the middle to upper reaches of River Lahn, where D. villosus co-occurs with native species. The latter river is the only navigable tributary considered in this study, and the fact that invasive D. villosus occur just up to the point where shipping activities stop suggests shipping as an important factor promoting their occurrence.

After its first observation in the Hollandsch Diep in 2006, the quagga mussel expanded in an upstream direction within the rivers, Rhine and Meuse. The species was found throughout the Dutch and Belgian sections of the Meuse River between 2008 and 2011, but was never reported from the Meuse in France, i.e., upstream of the Belgian border. Herein, this document reports the finding of the quagga mussel at two locations in the French section of this river. The lengths of the quagga mussels collected in this study – including the initial discovery of a 23.0 mm long individual in October 2011 – suggest that their original introduction into the Meuse River within France occurred in 2009 or earlier.

Ports are believed to be key factors in the process of dissemination of exotic marine species. However, direct sampling is very difficult in such areas due to their elevated turbidity and/or the danger related to shipping traffic. Within this study we propose the use of georeferenced TV underwater devices with high sensitivity for the inspection and monitoring of the exotic invasive species (EIS) Branchiomma luctuosum (Polychaeta, Sabellidae) in several ports from the Eastern Iberian coast (Western Mediterranean Sea, Spain). Many ports with different shipping activities were surveyed, from Cases d'Alcanar Port (Tarragona) to Santa Pola Port (Alicante). The use of this methodology contributed to the expansion of knowledge concerning the distribution and abundance of this species in the Eastern Iberian coast. This study proved the efficiency of this large scale sampling method and the possibility of its use in early detection and monitoring of this species and other conspicuous marine EIS which can be photo-identified.

The Chinese mystery snail (Bellamya chinensis) is an aquatic invasive species in North America. Little is known regarding this species’ impacts on freshwater ecosystems. It is believed that population densities can be high, yet no population estimates have been reported. We utilized a mark-recapture approach to generate a population estimate for Chinese mystery snail in Wild Plum Lake, a 6.47-ha reservoir in southeast Nebraska. We calculated, using bias-adjusted Lincoln-Petersen estimation, that there were approximately 664 adult snails within a 127 m2 transect (5.2 snails/m2). If this density was consistent throughout the littoral zone (<3 m in depth) of the reservoir, then the total adult population in this impoundment is estimated to be 253,570 snails, and the total Chinese mystery snail wet biomass is estimated to be 3,119 kg (643 kg/ha). If this density is confined to the depth sampled in this study (1.46 m), then the adult population is estimated to be 169,400 snails, and wet biomass is estimated to be 2,084 kg (643 kg/ha). Additional research is warranted to further test the utility of mark-recapture methods for aquatic snails and to better understand Chinese mystery snail distributions within reservoirs.

The common carp Cyprinus carpio is an omnivorous, highly fertile fractional spawner and a generalist species that can live in a wide range of biotic and abiotic conditions. The combination of these features contributes to their high invasiveness potential allowing its rapid spread and increased biomass. The species has already established in 91 out of 120 countries where it has been introduced, especially due to aquaculture and ornamental activities. This work, based on the presence of C. carpio inhabiting the Patos-Mirim system, Rio Grande do Sul, Brazil, provides the first evidence of advanced stages of gonadal development in both sexes, reinforcing the view that the species can adapt to regional environmental conditions and suggests high potential for establishment of self-sustaining populations in this system.

The naked goby Gobiosoma bosc (Lacepède, 1800), a western Atlantic gobiid species, has been recorded for the first time in European waters in October 2009. Seven specimens were caught by a stow net vessel at river km 45 in the Weser estuary (Germany) close to Sandstedt.

New Mediterranean records of the non-indigenous apogonid Cheilodipterus novemstriatus along the Lebanese coasts are presented. In July-August 2012, two individuals were spotted north of Beirut at 35-37 m depth on two separate occasions. A school of small-sized individuals was photographed in a nearby location a few weeks later. These findings confirm the presence and likely establishment of the species in the Mediterranean Sea.

The Golden anchovy Stolephorus insularis was recorded for the first time in the Mediterranean near Tel-Aviv, Israel on 7 August 2009. This northern Indian Ocean species evidently reached the Mediterranean by crossing the Suez Canal from the Red Sea. Since then, several specimens were collected over a period of time which indicates that this species has established a viable population in the Levant.