The Asian kelp Undaria pinnatifida (Harvey) Suringar 1873 was found for the first time in Belfast Lough, Northern Ireland during 2012 and was probably established in 2013. This currently is the most northern locality in Europe. The recent expansion around Britain is likely to continue with further colonisation in Ireland and extension to Scotland. Conditions are suitable for colonisation of Celtic, North and perhaps Norwegian Sea coasts, where it is likely to become an important fouling organism on marinas, aquaculture equipment, and other structures. Its preponderance on marina and other pontoons suggests artificial structures are its preferred initial sites of colonisation.

Increasingly, global trade and human movement have been transporting species between regions. Undaria pinnatifida (Harvey) Suringar, 1873, a macroalgae native to Korea and Japan, has been transported and became established in several temperate regions of the world. Here we report its presence in a new coastal area of northern Patagonia, Argentina, with a description of the sporophytes.

The shallow-water hydroid Clava multicornis is reported from the west coast of North America for the first time in nearly six decades. A North Atlantic species often occurring on intertidal fucoid algae, it had been found elsewhere only in heavily-invaded San Francisco Bay, California, with records dating from the late 19th to mid-20th centuries. The species has not been reported from the Bay Area since 1954, in spite of intensive recent collecting, and it is presumed to no longer exist there. During the winter and summer of 2013, robust colonies (which were fertile in the winter) were discovered in fouling communities on floating docks further north in Coos Bay, Oregon. This estuary harbours a large number of introduced species from both the western Pacific and the North Atlantic. We suspect that C. multicornis was introduced to Coos Bay in one of two ways. One means of transport might have been in hull fouling on ships, either directly from the North Atlantic or possibly from another Pacific coast estuary where the species remains undetected. A second possibility is on fucoid algae used in the shipment of polychaete bait worms from the State of Maine, on the Atlantic coast of the United States.

The solitary ascidian Herdmania momus (Savigny, 1816) was first recorded in the Eastern basin of the Mediterranean, off the coast of Israel, in 1958. Since then, H. momus established along the shores of Israel, albeit restricted to artificial substrates (e.g., pier pillars, artificial reefs, and shipwrecks) and deeper waters (20–30 m) in comparison to its native range. It has recently spread to natural substrates (i.e. the rocky reef) and shallow water environments (< 1 m). Field surveys, augmented by observations by recreational divers, were conducted along the Israeli Mediterranean coast on natural substrates to assess the present distribution. H. momus was detected on natural substrates at eleven sites, some of them at very shallow depths. This change in the distribution of H. momus that now includes natural substrates in shallow waters along with deep water environments may have negative impacts on the native fauna in the Eastern Mediterranean.

The Polychaeta Naineris setosa (Verrill, 1900) is reported for the first time in the Western Mediterranen Sea. Several specimens were collected in 2012 and 2013 in Boughrara Lagoon (Tunisia). The vector of introduction of N. setosa likely commercial shipping because Gabes is an international harbour with dense shipping traffic. A detailed description of specimens from Boughrara Lagoon is provided in this paper.

The spiny water flea (Bythotrephes longimanus), has successfully established populations in North American reservoirs and lakes, but little is known of its movement between lake and river systems. Here we document the first longitudinal movement of this aquatic invader in the Allegheny River, Pennsylvania. During spring 2013 we collected samples from the tailrace of Kinzua Dam to the confluence of Oil Creek, Oil City Pennsylvania, a distance of 100 km. The spiny water flea was present along 24 km of the sampled reach, comprising from 10 to 30% of the total zooplankton assemblage. In addition we collected two species of Daphnia, the dominant taxon, and Leptodora kindtii. All three developmental stages of the spiny water flea were present in samples collected (Instars I, II, and III). This study presents one of the first documented expansions of this species from an impoundment to downstream riverine reaches. Its presence warrants further monitoring and appropriate strategies to curb its spread and to investigate its potential impact on the lotic food web.

On 14 October 2012, two representative individuals (one male and one female) of an unidentified caprellid amphipod were collected from a mussel farm near Opotiki, northern New Zealand. These specimens were identified as Caprella andreae Mayer, 1890. This is the first record of this species from New Zealand waters and only the second record from the southern hemisphere. The wider distribution of C. andreae around New Zealand and any potential impacts are currently unknown.

The La Plata croaker (Pachyurus bonariensis) family Sciaenidae, is a small (< 23 cm) benthopelagic fish that originated in the Paraná-Paraguay-Uruguay river systems in South America. Its first record in the Patos Lagoon drainage area, Rio Grande do Sul (Brazil) occurred in 2001. This research reports for the first time, the occurrence of both juvenile and adult specimens of P. bonariensis in the São Gonçalo Channel (a 75 km long waterway between Patos and Mirim lagoon) and in the Mirim Lagoon, in 2005 and 2007 respectively. A total of 434 gonads were analyzed histologically from specimens captured by artisanal fishermen at Capilha, Mirim Lagoon between 2008 and 2010. Gonadal development was observed and described. Pachyurus bonariensis probably dispersed from northern Patos Lagoon in 2001 to the São Gonçalo Channel by 2005. The occurrence of adults in limnic waters in the São Gonçalo Channel and further south in the Mirim Lagoon in 2007, confirm that P. bonariensis is now an established species in Mirim Lagoon and could become a commercially important species to the artisanal fishermen of the area. Likewise at the limnetic northern parts of Patos Lagoon, P. bonariensis is now abundant at Mirin Lagoon and the ecological impacts of this range extension must be investigated.

The Indo-Pacific red lionfish Pterois volitans (Linnaeus, 1758) and devil firefish Pterois miles (Bennett, 1828) invasions through the western Atlantic, Caribbean, and Gulf of Mexico are reasonably well documented. While lionfish have been reported on multiple natural and artificial reefs in the Gulf of Mexico, this study notes their presence at previously undocumented mesophotic habitats and depths on natural banks in the northwestern Gulf of Mexico.

The European catfish, Silurus glanis is one of the largest freshwater fish worldwide. Although it originally inhabited rivers of Eastern Europe and Western Asia, this species is spreading within Europe, due to its popularity among anglers and interest in it as a potential species for aquaculture. This species has never been recorded in America until now. In August 2006, in the State of Santa Catarina, Southern Brazil, the local newspaper “Diário Catarinense” reported, with a photograph, the capture of a huge catfish by an amateur fisherman in the Itajaí-Açu River, which was identified as S. glanis. In March, 2010, the Laboratory of Ecology, Ichthyology and Fisheries (LEPI) of the Federal University of Paraná received another individual of S. glanis that had died in a small pond next to the Piquiri River, in the State of Paraná. Our aim is to report these two independent and geographically separate records of S. glanis in South America, as well as highlight our concerns about the illegal transport of aquatic organisms, which is a serious threat to the conservation of natural resources, especially in megadiverse regions such as Brazil.