The Shetland Islands, northern Scotland, have a highly active and diverse maritime environment, and local marine industries form an important part of the local economy. The potential for damage caused by non-native species is high. As part of an assessment of the current status of non-native species in Shetland, a series of rapid assessment surveys, coupled with a settlement panel monitoring programme, were carried out at 18 sites between May 2012 and October 2014. Eight non-native species were detected in our surveys, three of which (Corella eumyota Traustedt, 1882; Bugulina simplex Hincks, 1886; and Dasysiphonia japonica (Yendo) Kim, 2012) had not been previously recorded. Observations by SCUBA also reported the first UK record of Schizoporella japonica Ortmann 1890 growing on natural substrate. A literature review revealed three additional non-native species that have been documented in Shetland but were not detected in our survey work. The results from this study highlight the speed at which non-native species can spread over regional scales, and that more active harbours contain greater numbers of non-native species, indicating the potential of hull fouling and ballast water exchange for transporting non-native species.

From 29 June to 25 July 2014, scientists from Heriot Watt University and the Natural History Museum, London, aboard the vessel MV Halton, undertook a research cruise along the Norwegian coast. The cruise started in Bergen and over the two-week period surveys were conducted at intervals along the coastline, heading northwards, and including the major ports of Ålesund, Kristiansund, and Trondheim. When the vessel moored up in each harbour, surveys of the local pontoons were conducted to identify fouling species and to ascertain whether any non-native Bryozoa were present. Seven species of fouling Bryozoa were identified. Two of these were the non-native species Tricellaria inopinata d’Hondt and Occhipinti Ambrogi, 1985 and Schizoporella japonica Ortmann, 1890. This study represents the first confirmed records for these species from Norwegian coastal waters. It is likely, given the locations of occurrence, that small boat traffic was a vector for the introduction of these species. Recommendations are given for the amendment and addition of species to the Norwegian Black List.

Didemnum vexillum Kott, 1982 is a tunicate known as the carpet sea squirt that is non-native to the UK. It has been reported from sites in the UK and Ireland based on morphological characteristics. Here we present the results of Cytochrome Oxidase I mitochondrial gene analyses to confirm species identification of specimens taken from several of the sites around the UK mainland coast where non-native tunicate colonies have been reported. The results confirm the identity of the UK carpet sea squirt samples as Didemnum vexillum and provide additional information on COI haplotypes present in the UK.

Determining which factors contribute to the establishment and spread of an introduced species is a challenge with substantial management implications, especially when that species is found associated with another introduced species. Here, we report for the first time the presence of two introduced species, the macroalga Undaria pinnatifida (Harvey) Suringar, 1873 and the clubbed tunicate Styela clava (Herdman, 1881), in San Antonio Bay (northern Patagonia), where apparent facilitation by the tunicate may be contributing to the establishment of the algae. Because S. clava is an ecosystem engineer and acts as a facilitator for the settlement (and further growth) of other species, it may create habitats that are more suitable for U. pinnatifida invasion at locations not yet colonized by the algae.

Specimens of the North American leech, Placobdella ornata (Verrill, 1872) were confirmed from the Donkmeer, a freshwater lake in the province of East Flanders, Belgium, by morphological and molecular analysis. Leech specimens from Belgium were morphologically consistent with the syntype series and description of P. ornata by Verrill (1872). Molecular comparison of the Belgian specimens to specimens of P. ornata from the type locality (New Haven, Connecticut, USA) using the cytochrome c oxidase subunit I (COI) gene revealed a similarity of 99.5%. Placobdella ornata from Belgium is the first documentation of a second species of the genus Placobdella in Europe.

The freshwater snail identified as Physastra sumatrana has been recorded in Singapore since the late 1980’s. It is distributed throughout the island and commonly associated with ornamental aquatic plants. Although the species has previously been considered by some to be native to Singapore, its origin is currently categorised as unknown. Morphological comparisons of freshly collected specimens and material in museum collections with type material, together with DNA barcoding, show that both Physastra sumatrana, and a recent gastropod record of Stenophysa spathidophallus, in Singapore are actually the same species—the globally-invasive Physa acuta. An unidentified physid snail was also collected from the Singapore aquarium trade.

The invasion of North American waters by Dreissena polymorpha (zebra mussel) and its subsequent ecological impacts has been well documented. Their spread continues to new states and watersheds despite a wealth of research and outreach campaigns, albeit at a slowed pace. We describe the spread and proliferation of zebra mussel into one of the more recently invaded states, Maryland, USA. Veliger counts and fixed hard surface monitoring suggest that a population is established within the lower Susquehanna River to the head of the Chesapeake Bay. A relatively narrow tidal-freshwater habitat envelope with suitable salinity may serve to restrict zebra mussel dispersal further downstream. Dispersal to other freshwater habitats in Maryland seems likely as the current area of infestation is highly used by commercial and recreational boaters, although regulations are in place that could help slow or prevent spread. Successful invasion will likely be a function of water chemistry, which may be limiting in some parts of the state.

Eualetes tulipa (Rousseau in Chenu, 1843), a marine worm snail (family Vermetidae), was collected in the Royapuram fishing harbour, Chennai, coast of India. The identity of the species, initially based on morphology, was confirmed by molecular analysis (cytochrome oxidase I). Collected from submerged boulders of a breakwater at depths from 0.5 to 1.0 m, this represents the first record of the species from the coast of India. Its population density at the site was up to 55 individuals/m². Elsewhere, Eualetes tulipa has been recorded as an invasive species from the coasts of Hawaii and from Venezuela in the Caribbean Sea. The source of its introduction was likely fouling from the hull of a ship, although transport in ballast water is also possible.

The balanoid barnacle, Amphibalanus improvisus (Darwin, 1854), was found on the carapaces of two invasive species of mitten crabs: Eriocheir sinensis H. Milne Edwards, 1853 and E. hepuensis Dai, 1991. The first instance was from a female mitten crab captured from the River Thames estuary, Kent, England, where A. improvisus is common. However, the second record, on a Hepu mitten crab from Iraq is the first record of A. improvisus from the Persian Gulf.

Despite the large number of biological invasion studies, little is known about non-indigenous caprellids in the eastern Pacific. This study represents the first record of Paracaprella pusilla Mayer, 1890, an invasive species, in the northern tropical east Pacific (NTEP) region. Caprellids were collected from June 2013 to March 2014 on fouling substrates (mainly macroalgae, sponge, and bryozoans) associated with artificial structures at four sites from the Mexican Pacific. Marinas, sheltered waters, and aquaculture farms appeared to function as caprellid nurseries and may act as distribution points to other localities. P. pusilla inhabited a wide range of artificial structures, which appears to increase their survival success and may facilitate their dispersal to new locations in the eastern Pacific Ocean.

This contribution reports, for the first time, the presence of the giant tiger shrimp Penaeus monodon Fabricius, 1798 on the northern Caribbean coast of Costa Rica. This closed-thelycum penaeid species is originally from the Indo-West Pacific, and it has been reported from other regions of the Western Central Atlantic; however, the reproductive biology of this species has not been examined in its non-native range. Adult females and adult males were captured by local fishermen near the Colorado River mouth during September and October 2014; animals were preserved in ethanol for further identification, and an evaluation of reproductive condition was conducted based on visual and histological staging of ovaries. Terminal ampoules of males were analyzed histologically to document spermatogenic activity. The specimens examined exhibited ovarian maturation, spermatophore production, and evidence of successful mating. The presence of this species can affect food chains and disturb ecosystem f unction and structure and locations where it is not native, which can, in turn, threaten ecosystem services to people dependent on this ecosystem for their livelihood.

Since 2013, more than 60 specimens of the Amur sleeper, Perccottus glenii Dybowski, 1877 have been captured in four minor watercourses of the Upper Danube, in Bavaria, Germany. Its occurrence in the wild is probably due to unintentional release incidences from nearby enclosed fishponds. An ecological risk assessment showed that this species is a threat to freshwater faunal biodiversity in Germany and has been assigned to the German Action list of invasive alien species. In accordance with nature conservation efforts, effective management policies should urgently be developed and implemented by the appropriate authorities to prevent further dispersal of the Amur sleeper in Germany. The establishment and uncontrolled spread of this invasive alien species in the Upper Danube watercourse and other habitats in Europe can be expected, if preventative measures are not immediately put in place.