This technical paper presents results from pilot field trials conducted on the novel use of a biodegradable jute material to eradicate the highly invasive aquatic macrophyte Lagarosiphon major Ridley from Lough Corrib, Ireland. The results demonstrate the ability of the jute material to comprehensively kill L. major and to restore native macrophyte communities to areas of the lake that were previously overgrown with this priority invasive species. To date, eight indigenous plant species (four charophytes and four angiosperms) have been recorded growing through the loose-weave jute fabric. However, no Lagarosiphon has been recorded as doing so. This material has the potential for broader application in the management of nuisance aquatic weeds and in the restoration of native flora extirpated by these alien species.

Over the past 60-70 years, the invasive Indo-Pacific coral Tubastraea coccinea Lesson, 1829 (Cnidaria, Scleractinia) has colonized the western tropical Atlantic Ocean - the Americas, the Antilles, northern Gulf of Mexico (GOM), and many of its 3,600 oil/gas platforms. It is now the single, most abundant coral on artificial substrata in the GOM, with hundreds of thousands of colonies on a single platform. Here, we report for the first time the observation of a closely related congener in the western Atlantic – the Indo-Pacific azooxanthellate Tubastraea micranthus (Ehrenberg, 1834) – and suggest that it may pose a threat similar to T. coccinea. A total of 83 platforms, including deep-water, toppled, Rigs-to-Reefs structures, were surveyed in the northern Gulf of Mexico between 2000 and 2009, from Matagorda Island, Texas to Mobile, Alabama, USA, between the depths of 7 and 37 m, by SCUBA divers. Five platforms were surveyed by Remotely Operated Vehicle (ROV) to depths of up to 117 m. T. micranthus was found on only one platform – Grand Isle 93 (GI-93), off Port Fourchon, Louisiana, near the Mississippi River mouth, at the cross-roads of two major safety fairways/shipping lanes transited by large international commercial ships. The introduction appears to be recent, probably derived from the ballast water or hull of a vessel from the Indo-Pacific. If the growth and reproductive rates of T. micranthus, both sexual and asexual, are similar to those of T. coccinea, this species could dominate this region like its congener. It is not known whether this species is an opportunist/pioneer species, like T. coccinea, a trait protecting benthic communities from its dominance. The question of rapid-response eradication is raised.

A non-native population of plains minnow Hybognathus placitus in the Pecos River, New Mexico, USA, replaced the endemic, ecologically similar Rio Grande silvery minnow Hybognathus amarus in less than 10 years. Competitive exclusion is hypothesized as a mechanism of replacement. The following evidence was examined for potential support: (1) the historical population trend of H. amarus versus H. placitus; (2) relative suitability of the modified flow regime for H. amarus versus H. placitus; (3) potential for habitat overlap; and (4) spawning periodicity and body length in the non-native population of H. placitus. Historical data indicate H. amarus did not decline until H. placitus was present, after which it disappeared rapidly and H. placitus proliferated. The natural flow regime of the Pecos River was changed via base-flow reductions and capture of spring-snowmelt runoff, making it similar to flow regimes associated with likely source populations of non-native H. placitus. Spring runoff is an important spawning cue for H. amarus, but not H. placitus and H. placitus appears to be naturally more tolerant of diminished streamflow. Extant H. placitus were associated with a relatively pristine river reach that was most likely the stronghold for the replaced H. amarus population. Given high ecological similarity, habitat overlap was likely high during the period of replacement. Hybognathus placitus in the Pecos River had a protracted spawning season (April through September), whereas extant H. amarus in the Rio Grande had a short spawning season (a few days in May or June during snowmelt runoff). Most H. amarus die after their first spawning season and few exceed 60 mm standard length (SL), whereas quite a few H. placitus survive at least until their second spawning season and exceed 60 mm SL. Co-occurrence of multiple spawning cohorts may stabilize annual reproductive output of H. placitus and larger individuals may be more fecund and produce larger eggs that survive better. Spawning flexibility, greater size, and higher environmental tolerance likely gave H. placitus a reproductive and survival advantage over H. amarus, consistent with a deterministic pattern of rapid species replacements in the plains, in which tolerant, competitive species from the Red River drainage or Gulf of Mexico coast rapidly replace more sensitive, endemic congeners in disturbed, remnant habitats.

The introduced range of the European cyprinid, sunbleak Leucaspius delineatus, in England was previously limited to parts of southwest England but has now expanded across Southern England. Natural dispersal mechanisms cannot explain their increased distribution and fish stocking was not a factor. Thus, the accidental movement of either their eggs or larvae via anglers’ nets was believed to be the mechanism by which these fish were accidentally moved between waters over 100 km apart. This dispersal pathway is difficult to regulate, as is the release of unwanted non-native aquarium and pond fish into open waters by the public. This latter pathway has resulted in the recent releases of species including walking catfish Clarias batrachus, Asian weatherfish Misgurnus mizolepis and white catfish Ameiurus catus.

Biotic resistance, through competition from native species, can limit the success of invasive species. Similarly, invasive species can impact natives when they reduce shared resources. Alternatively, some invaders may benefit natives if they either directly or indirectly increase resource acquisition by natives. I predicted that the native California killifish, Fundulus parvipinnis would reduce the fitness of the morphologically similar introduced sailfin molly, Poecilia latipinna in a California estuary. A field experiment found no effect of competition; increasing the density of the native killifish did not affect sailfin molly growth. However, there was an unanticipated positive association of female sailfin molly density on growth of native killifish. Unlike any other native fish in the estuary, the introduced molly is a live bearer and I hypothesize that the presence of female mollies may have generated a novel food source (newborn fish) for the native competitor. This potential food source could have overcompensated for any potential competition for other resources. The positive effect was not mutual, i.e., the presence of killifish did not increase the growth of adult mollies (killifish are oviparous and lay eggs on the substrate). While killifish may not limit mollies through competitive effects, they could provide partial resistance to invasion by preying on juvenile mollies. Additional experiments designed specifically to test whether juvenile mollies increase killifish growth would confirm the mechanism and potentially reveal the importance of this in nature. Considering the role of all life stages of an invader is a key step when evaluating interactions with natives and determining the success and impacts of introduced species.

The Southern Hemisphere unitary ascidian Corella eumyota was discovered in 2002 in France and is now widespread on the southern coast of England and in Ireland. It has also been reported from seabed surveys in Ría de Vigo, north-west Spain. Surveys of marinas in February 2008 and June-July 2009 identified additional localities in Ría de Vigo and revealed widespread occurrence of C. eumyota on the Atlantic coast of the Iberian Peninsula. The species was very abundant on some structures built less than two years before the surveys, indicating a capacity for very rapid colonization and population increase. This suggests that the species is a potential threat to biodiversity and aquaculture interests. Records of the non-native ascidians Styela clava, S. plicata, Perophora japonica, Botrylloides violaceus, and Didemnum vexillum are also reported.

The ascidian Corella eumyota, originally from the Southern Hemisphere, was first reported in the Northern Hemisphere in Brittany, France, in 2002. Since then, it has been recorded in Spain, Ireland, the south coast of England and South Wales. Most European records to date have been from artificial habitats such as marinas. In Plymouth, England, C. eumyota was first found in two marinas in 2005 but individuals were soon also detected in small numbers on nearby shores. Shore surveys in March and August of 2008 indicated that C. eumyota has established reproductive populations on natural and semi-natural shores of Plymouth Sound and the adjacent coastline, largely restricted to relatively sheltered sites in the lower reaches of estuaries. At these sites it is generally the most abundant non-colonial ascidian. The species clearly has the capacity to become a significant component of the biota of sheltered shores in the Northern Hemisphere.

The ascidian Phallusia nigra is listed among the non-indigenous species of the Mediterranean Sea and its first occurrence in Hellenic waters is noted here. The westward expansion of the black sea squirt from the north Levantine coast, up to the Aegean Sea has been revealed by scuba diving, as established populations were recorded offshore and in one of the harbours of Rhodes Island. Maintenance conditions of the species in captivity are briefly discussed.

We report the first record of the colonial tunicate Clavelina lepadiformis (Müller, 1776) in the northwest Atlantic. Populations were found along the eastern Connecticut shoreline in October 2009. At one site C. lepadiformis had a mean percent cover of 19.95% (±4.16 S.E.). A regional survey suggests that the invasion is relatively localized. Genetic analysis confirms our morphological identification and places the introduced population in the previously described ‘Atlantic clade’. While it appears Clavelina lepadiformis is currently in the incipient stage of introduction in eastern Connecticut waters, its spread to other areas in the region could lead to competition with resident members of shallow water epifaunal assemblages and shellfish species.

The benthic foraminiferal fauna in Pamucak Cove (NW Kuşadası, Turkey) was investigated. A rich foraminiferal assemblage was observed around submarine springs, which were located 200 m off the coast. This foraminiferal assemblage is typical Mediterranean. However, the abundance of alien species is noteworthy. Fourteen alien foraminifera were found. Indo-pacific originated species; Quinqueloculina sp. C, Triloculina sp. A, Pyramidulina catesbyi (d’Orbigny), Brizalina simpsoni (Heron-Allen and Earland) and Amphistegina lessonii d’Orbigny were observed for the first time on the Turkish coastline. Specimens of Haddonia sp. and Cymbaloporetta plana (Cushman), abundantly observed in SW Antalya and Nodopthalmidium antillarum (Cushman), previously recorded from Iskenderun were also found in the study area, these are the first records for these species in the Aegean Sea. In addition, seven individuals of Euthymonacha polita (Chapman) were found around the springs, and this constitutes the first record of this species in the entire Mediterranean Sea.

Calyptraeid gastropods are common fouling organisms in some areas, and have been introduced frequently into bays and ports in the northern hemisphere. In some cases, introduced calyptraeids have spread extensively, while several other calyptraeid introductions have persisted but failed to expand geographically. Calyptraeid species are often difficult to identify to species making it difficult to identify the origin of many introductions. Here we use DNA sequence data to confirm that a Mediterranean population of the spiny slipper snail Bostrycapulus, previously referred to as B. aculeatus and B. calyptraeformis, is in fact B. odites from the South Atlantic, and that this population probably originated in South America.

Specimens belonging to North American representatives of the genus Planorbella Haldeman, 1842 of the gastropod family Planorbidae were found for the first time living at the inlet of a warm stream running from the Ust-Ilimsk Pulp and Paper Plant into the Angara River along with the two common indigenous species Galba truncatula (Pulmonata: Lymnaeidae) and Sibirenauta sibirica (Pulmonata: Physidae). Morphological studies of the shell, the radula and the genitals showed that the newly found Planorbella specimens can most likely be attributed to P. duryi duryi (Wetherby, 1879) while it also contains morphological characters of other species in this genus. It is assumed that the occurrence of Planorbella in East Siberian water bodies is a result of unintentional release from aquarium tanks.

Sampling in May 2008 by the author in the Main-Danube canal (Germany) as well as earlier sampling by Van der Velde and Platvoet (2007) indicated that the quagga mussel introduction into Western Europe was not the result of range expansion from its native range through the River Danube and subsequently the Main-Danube canal and River Rhine, as previously suggested. Ballast water transport and release in the Hollandsch Diep, a section of one of the distributaries in the Rhine delta (The Netherlands), is now considered the most likely vector and dispersal source.

In 2008, the killer shrimp, Dikerogammarus villosus, native to the Ponto-Caspian region, was found for the first time in Central Italy, in Bilancino, an artificial lake situated in the watershed of the River Arno (Tuscany). This new record shows that this species’ range is expanding in Italy. It is thus imperative to identify the pathways and vectors of spread of this species in order to halt this invasion process.

A single female specimen of the blue crab Callinectes sapidus Rathbun, 1896 was captured by a fisherman on 26 May 2008 in the East Frisian Wadden Sea, National Park of Lower Saxony, Germany. The specimen was transferred to a public marine aquarium in Dorumersiel. On 9 June 2008 the female extruded masses of fertilized eggs. Due to nature conservation efforts in this national park, management instructions are implemented by the appropriate authority for further dealing with the captured specimen and its potential offspring. This is the second record of a mature female and the first record of a fertilized female blue crab from German coastal waters of the North Sea.

The presence of the blue crab Callinectes sapidus has been recently recorded in the Lagoon of Patok. Twelve individuals from this lagoon have been observed and measured during October 2009. Based on carapace measurements most of these crabs can be considered as mature. The population of the blue crab seems to be increasing and can be considered as established in Patok area.

We register here the first occurrence of the “dourado” Salminus brasiliensis (family: Characidae) in Salto Santiago Reservoir in the Iguaçu River basin, Paraná State, Brazil, a global biodiversity ecoregion with an extremely rich endemic ichthyofauna. The single specimen captured, an adult female measuring 480-mm total length, was taken with gillnet in January 2008. No additional S. brasiliensis were captured during general fish surveys conducted at four sites in the reservoir even though multiple types of gear were used (gill and trammel nets and long-line fishing) over a period of nearly two years (bimonthly from July 2006 to September 2008). The presence of S. brasiliensis, a large, predacious freshwater species native to other parts of Brazil, may be related to its use as a sport fish, and the single specimen taken from the reservoir may have escaped from ponds built by aquaculturists for recreational angling. Before appropriate management measures are taken, additional field work is needed to determine the status and distribution of S. brasiliensis in the Iguaçu basin and to assess possible negative effects of the introduction on native fishes.