Showing papers in "Aquatic Invasions in 2010"

Update on geographic spread of invasive lionfishes (Pterois volitans (Linnaeus, 1758) and P. miles (Bennett, 1828)) in the Western North Atlantic Ocean, Caribbean Sea and Gulf of Mexico

Abstract: The Indo-Pacific lionfishes (Pterois volitans [Linnaeus, 1758] and P. miles [Bennett, 1828]: Family Scorpaenidae) are the first nonnative marine fishes to establish in the Western North Atlantic/Caribbean region. The chronology of the invasion was reported last year (Schofield 2009) using records from the US Geological Survey’s Nonindigenous Aquatic Species database. This article provides an update of lionfish geographic spread (as of October 2010) and predictions of future range.

Impacts of non-native fishes on Iberian freshwater ichthyofauna: current knowledge and gaps

Abstract: The Iberian Peninsula contains a highly endemic freshwater ichthyofauna that is being homogenized and threatened by an increasing number of non-native fishes. Here, in this paper, I reviewed the literature on the impacts of fish introductions and translocations on the native Iberian ichthyofauna. The aims of the present review were (1) to provide an overview of the already studied and proven impacts as well as of the suggested potential impacts that remain to be tested, (2) to synthesize the current knowledge in the Iberian Peninsula and (3) to suggest future research approaches. Despite some well-documented impacts, an increasing number of non-native fish species and a wide range of diverse ecological situations uncover knowledge gaps which hamper conservation and management efforts. Since the introduction of species is often pointed out as a major cause of extinctions, I encourage research groups and funding agencies to devote more resources to the study of interactions between nonnative and native fishes in order to develop evidence-based species-specific impact assessments.

The Ponto-Caspian 'killer shrimp', Dikerogammarus villosus (Sowinsky, 1894), invades the British Isles

Abstract: The Ponto-Caspian amphipod Dikerogammarus villosus was found both in the margins and open water areas of Grafham Water, a large reservoir in Cambridgeshire, U.K., in September 2010. Both adults and juveniles were present in large numbers and were most frequent in the boulder/cobble areas dominating the margins of the reservoir. Precopula pairs were also evident, as were egg bearing females.

Review and new records of non-indigenous freshwater invertebrates in the Ebro River basin (Northeast Spain)

Abstract: This paper is the first attempt to compile a list of the non-indigenous aquatic invertebrate species currently known to occur in the Ebro River basin (Northeast Spain). A total of 23 exotic aquatic species have been recorded in this area, and one more (the branchiobdellida Xironogiton victoriensis) may also be present in this Iberian basin. Due to the negative impacts that biological invasions cause to ecosystems and to human activities, it is important to state the introduction pathways and prevent the spread of already introduced species. In order to fight against biological alien species invasions, development of national strategies on invasive alien species and international cooperation are considered essential.

Experimental evidence for positive effects of invasive seaweed on native invertebrates via habitat-formation in a seagrass bed.

Abstract: Relatively few studies have aimed to test if invasive species have positive effects on native species, for example via formation of habitat or by amelioration of environmental stress-conditions. The red macroalga Gracilaria vermiculophylla, from the West Pacific, is invading estuarine mudflat and seagrass habitats along East Pacific and East and West Atlantic coastlines. I tested if low (55-110 g WW m -2 ) and high (220-440 g WW m -2 ) densities of G. vermiculophylla have positive or negative effects on the macroinvertebrates (> 2 mm) that inhabit Zostera marina seagrass beds. The experiment was conducted over 34 days at both 0.5 and 2 m depth at Snaptun Harbor, Denmark. I found positive effects of Gracilaria on most invertebrates, with statistically significant results for “all invertebrates”, “gastropods”, and “bivalves”, and a near-significant result for “crustaceans”. Both quantitative and qualitative habitat-resource models may explain these positive effects; i.e. “more habitats” exist in the presence of Gracilaria and/or the “habitat differs” between Gracilaria and Zostera vegetation. Future studies should test these two general explanatory models and quantify (a) if density thresholds exists were effects shift from positive to negative, (b) specific mechanism whereby positive effects occur, (c) if Gracilaria provide a novel or substitute drift algal habitat, and (d) the largerscale ecosystem implications of this invasion.

First evidence for an established Marmorkrebs (Decapoda, Astacida, Cambaridae) population in Southwestern Germany, in syntopic occurrence with Orconectes limosus (Rafinesque, 1817)

Abstract: Marmorkrebs are one of 12 currently known non-indigenous crayfish species (NICS) to be found in Central European waters. It is unique in the manner that there exist only females which reproduce parthenogenetically, i.e. eggs develop unfertilized and all offspring are genetically identical. Marmorkrebs have been first discovered in the German aquarium trade in the mid 1990s and became a very common pet species since then. Here, we present first evidence for a well established Marmorkrebs population in a small lake in the Upper Rhine catchment near Freiburg (Germany). The population occurs syntopically with Orconectes limosus, another NICS which invaded the Rhine system about 50 years ago. Morphometric and ovary weight measurements were taken from 12 Marmorkrebs specimens that were captured on July 3, 2010. The rostrum spination was pronounced and resembled the one found on a free-living individual captured in Saxony (Germany). Ovary development stages (Gonadosomatic Index) were heterogeneous and single berried females were found from early June to late July, which might indicate an asynchronous breeding habit. The relative abundance and distribution of both crayfish species were assessed by visual counts at nighttime at two occasions. Both species attained a comparable, moderate density throughout the lake margin. The Marmorkrebs was the prevalent species on shallow, swampy habitat patches, which are presumably similar to its natural prime habitats. The successful establishment of Marmorkrebs despite a pre-existing O. limosus population, stresses the competitive ability of Marmorkrebs. In addition to the recently suggested hypothesis that Marmorkrebs might be temperature limited in most parts of Europe, we feel that it is also necessary to consider its probable natural prime habitats and life cycle: Marmorkrebs are presumably able to colonize summer-warm, lentic habitats in most parts of Central Europe.

Forecasting the expansion of the invasive golden mussel Limnoperna fortunei in Brazilian and North American rivers based on its occurrence in the Paraguay River and Pantanal wetland of Brazil.

Abstract: The bivalve Limnoperna fortunei (Dunker, 1857), also called golden mussel, is native to Asia but becoming dispersed around the world. The golden mussel resembles the invasive dreissenid bivalves in many respects, and although much less studied it evidently has broader environmental tolerances. The golden mussel was introduced into the La Plata River estuary (South America) and quickly expanded upstream to the north, into the tropical Paraguay River reaching a large floodplain area in Brazil known as the Pantanal wetland. The golden mussel tolerates environmental conditions in the Pantanal that would be inhospitable for most bivalves, but mussel mortality has been observed during the most extreme oxygen depletion events. Based on knowledge about the limiting factors for the golden mussel in the Pantanal wetland, its potential distribution was predicted for the remainder of the Paraguay River basin where the species is not present, as well as in other river systems throughout Brazil. Forecasts of potential distribution in Brazilian river systems were based on physicochemical limitations for shell calcification, and specifically on lower thresholds of dissolved calcium concentrations and the calcium carbonate (calcite) index of saturation, which may be a better indicator of calcification potential in low-calcium waters than calcium concentration alone. In addition to examining spatial patterns in calcium and calcification potential, these and other limnological and climate variables were used in ecological niche modeling using GARP and Maxent algorithms. Forecasts of potential distributions in three major North American river systems (Mississippi, Colorado, and Rio Grande) were based mainly on water temperature because calcium availability and calcification evidently would not be limiting to golden mussel establishment in those waters. Due to the greater tolerance of the golden mussel to conditions known to limit other bivalves, as well as its greater ability for shell calcification in low-calcium water, the golden mussel could potentially become broadly distributed throughout Brazil. According to its thermal tolerance L. fortunei could become established in the Mississippi, Colorado and Rio Grande drainage systems, although the northern Mississippi River system including the Missouri River may be too cool in the winter to support the golden mussel.

A novel approach to aquatic weed control and habitat restoration using biodegradable jute matting

Abstract: 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.

Non-native, invasive Red lionfish (Pterois volitans (Linnaeus, 1758): Scorpaenidae), is first recorded in the southern Gulf of Mexico, off the northern Yucatan Peninsula, Mexico

Abstract: We recorded the first sighting and collection of the non-native, invasive red lionfish (Pterois volitans (Linnaeus, 1758): Scorpaenidae) in the southern Gulf of Mexico, off the northern Yucatan Peninsula. In December 2009, two individuals were sighted (one of them speared) at 38 m depth over a reef formation, about 58 km northwest of the Alacranes Reef National Park, which is located 130 km off the northern coast of the Yucatan Peninsula, Mexico. More than 20 years after the introduction of P. volitans into the western Atlantic, specifically off the Florida and North Carolina coasts, the invasion circuit now appears to be closing in, since this new record was made about 800 km from the Dry Tortugas and Marquesas, Florida. This recording appears to be the first introgression of the P. volitans population into the Gulf of Mexico via larval transport.

Non-native fishes of Belarus: diversity, distribution, and risk classification using the Fish Invasiveness Screening Kit.

Abstract: As of the end of 2008, 25 species of non-native fishes have been documented in the Republic of Belarus. Of these, 17 (68%) species were deliberately introduced for aquaculture, six (24%) species invaded from the adjacent territories by natural dispersal, and two (8%) species were likely introduced accidentally. During the 20th century, the number of non-native fishes in Belarus increased exponentially, resulting in significant shifts in taxonomic composition of the country's ichthyofauna. For the first time, we assessed the invasive potential of the introduced fishes by applying a uniform protocol, the Fish Invasiveness Screening Kit (FISK). Based on the total FISK scores, all the non-native fishes in Belarus were classified into two groups: high and medium risk of becoming invasive. In terms of the economic sectors at risk ('aquacultural/fisheries', 'environmental', and 'nuisance'), all species were classified into three distinct groups. The highest risk to all of these sectors wa s posed by the brown bullhead Ameiurus nebulosus Le Sueur, 1819, gibel carp Carassius gibelio (Bloch, 1782), round goby Neogobius melanostomus (Pallas, 1814), Amur sleeper Perccottus glenii Dybowski, 1877, and topmouth gudgeon Pseudorasbora parva (Temminck & Schlegel, 1846). The two risk categories identified in the present study can be used in prioritizing the resources for the management of non-native fish species of Belarus and in countries with similar environmental conditions.

Eradication of introduced signal crayfish Pasifastacus leniusculus using the pharmaceutical BETAMAX VET.

Abstract: Signal crayfish Pasifastacus leniusculus were first discovered in Norway in the Dammane area of Telemark County in October 2006. This introduced population was found to be infected with the oomycete Aphanomyces astaci, the causative agent of crayfish plague. The Dammane watershed consists of 5 small ponds, the largest with a surface area of approximately 2000 m 2 . The Norwegian National Veterinary Institute conducted a feasibility study for the eradication of the Dammane signal crayfish population at the request of the Norwegian Food Safety Authority and Directorate for Nature Management. This study recommended the use of the pharmaceutical BETAMAX VET. ® , followed by pond drainage as a feasible course of action. BETAMAX VET. ® is a cypermethrin-based pharmaceutical developed for treatment of salmon louse (Lepeophtherius salmonis) infestations of farmed Atlantic salmon (Salmo salar). Cypermethrin is a synthetic pyrethroid and a common agent in many insecticides licensed throughout Europe. Following a comprehensive mapping of the Dammane watershed, the ponds were treated with BETAMAX VET.

A new coral species introduced into the Atlantic Ocean – Tubastraea micranthus (Ehrenberg 1834) (Cnidaria, Anthozoa, Scleractinia): an invasive threat?

Abstract: Over the past 60-70 years, the invasive Indo-Pacific coral Tubastraea coccinea (Lesson 1830; 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

The first record of the parthenogenetic Marmorkrebs (Decapoda, Astacida, Cambaridae) in the wild in Saxony (Germany) raises the question of its actual threat to European freshwater ecosystems.

Abstract: A cambarid specimen was collected in a brook in Saxony (south-east Germany). Preliminary morphological inspection identified it as the parthenogenetic Marmorkrebs (Decapoda, Astacida, Cambaridae). However, this individual showed some striking morphological differences compared to specimens of our laboratory Marmorkrebs culture. Hence, we conducted a molecular analysis based on two mitochondrial genes, COI and 12S, to check its identity. The results of the genetic study verified the initial assumption of a Marmorkrebs identity for the Saxon specimen. Thus, in addition to the two indigenous species, the new find is the fourth recorded introduced crayfish species in this area. However, a search for further Marmorkrebs specimens at the same site was not successful. Most published records of Marmorkrebs in European waters concern just single individuals and an established population has so far not been observed. This stands in contrast to other recently introduced cambarid species. Thus, we critically discuss the potential of the Marmorkrebs to spread within Europe. The major obstacle may be that the temperature necessary for optimal development and reproduction of the Marmorkrebs is significantly higher than that found in most European waters. However, given globally increasing temperatures, this might change in the future.

First occurrence of the invasive tunicate Didemnum vexillum in eelgrass habitat

Abstract: During the late 20th century, several species of alien tunicates invaded New England marine coastal waters. In Autumn 2008, we surveyed for tunicates in Lake Tashmoo, a protected marine pond with shellfish aquaculture operations and restored bay scallop Argopecten irradians irradians habitat on Martha's Vineyard, Massachusetts. We found the invasive tunicates Ascidiella aspersa, Botrylloides violaceus, Botryllus schlosseri, Didemnum vexillum, Diplosoma listerianum, Styela clava and native tunicate Molgula manhattensis attached to artificial substrates throughout Lake Tashmoo and B. violaceus, B. schlosseri, D. vexillum, D. listerianum and M. manhattensis attached to eelgrass Zostera marina in the middle of Lake Tashmoo. Tunicates were growing on the stalk and blade of in situ eelgrass, floating pieces of eelgrass (a transport and dispersal mechanism), and pieces of eelgrass in fouling communities on boat hulls and aquaculture floats. Botrylloides violaceus, B. schlosseri, D. listerianum and M. manhattensis have been previously recorded as utilizing eelgrass as substrate, but this is the first recorded occurrence of D. vexillum to utilize eelgrass as substrate. Perhaps because of lack of substrate space in Lake Tashmoo, D. vexillum spread to eelgrass. Eelgrass serves as a juvenile shellfish and fish habitat and threats to it are of concern by coastal managers and the fishing industry.

High abundance of the jellyfish Aurelia aurita excludes the invasive ctenophore Mnemiopsis leidyi to establish in a shallow cove (Kertinge Nor, Denmark).

Abstract: The population dynamics of the invasive ctenophore Mnemiopsis leidyi, which showed mass occurrence in Kerteminde Fjord (Denmark) for the first time in 2007, and the indigenous common jellyfish, Aurelia aurita, was followed in the fjord system Kerteminde Fjord/Kertinge Nor during late 2008 and 2009. The population density of A. aurita was always highest in Kertinge Nor while the density of M. leidyi was always highest in Kerteminde Fjord, indicating recruitment of the ctenophore from the adjacent sea (Great Belt). In the shallow cove of Kertinge Nor, the first A. aurita ephyrae appeared in March, by the end of May the medusae had obtained their maximum umbrella diameter of only 30 mm due to food limitation, and the estimated half-life of zooplankton was very low, <1 day from May to September 2009. The high predation impact explains why the holopelagic ctenophore, which presumably survives the winter in the adjacent open sea, is likely to be outcompeted in Kertinge Nor where the polyp stage of A. aurita every spring ensures a very large population of very small medusae. The population density of jellyfish, in Kertinge Nor, during the summer period is dependent on the extend of flush-out due to density-driven water exchange. A survey of data obtained every year in August since 1991 indicates that the unusually high population density (36 ± 34 ind. m -3 ) and the small umbrella diameter (56 ± 5 mm) of A. aurita have remained unchanged during the last 20 years, and further, that a relatively high population density of jellyfish in certain years is correlated with a relatively small mean umbrella

Marivagia stellata gen. et sp. nov. (Scyphozoa: Rhizostomeae: Cepheidae), another alien jellyfish from the Mediterranean coast of Israel

Abstract: Two specimens of an unknown jellyfish species were collected in Bat Gallim and Beit Yannai, on the Mediterranean coast of Israel, in June and July 2010. Morphological characters identified it as a cepheid (Cnidaria, Scyphozoa, Rhizostomeae). However, the specimens showed remarkable differences from other cepheid genera; unlike Cephea and Netrostoma it lacks warts or knobs centrally on the exumbrella and filaments on oral disk and between mouths, and it differs from Cotylorhiza in its proximally loose anastomosed radial canals and in lacking stalked suckers and filaments on the moutharms. We thus describe it herein as Marivagia stellata gen. et sp. nov. We also present the results of molecular analyses based on mitochondrial cytochrome oxidase I (COI) and 28S ribosomal DNA, which support its placement among the Cepheidae and also provide its barcode signature. This new find is the fourth introduced scyphozoan species recorded in the Mediterranean. The presence of a sexually mature specimen collected as far back as 2006, and the occurrence of the species this summer at sites nearly 90 kms apart, indicate the existence of an established population.

The establishment of blue crab Callinectes sapidus Rathbun, 1896 in the Lagoon of Patok, Albania (south-east Adriatic Sea)

Abstract: 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.

The spread of the parthenogenetic marbled crayfish, Marmorkrebs (Procambarus sp.), in the North American pet trade.

Abstract: The parthenogenetic marbled crayfish Marmorkrebs was discovered in the pet trade in Europe in the 1990s. Since then, its distribution through the pet trade has spread from Europe to other continents, including North America. North American pet owners were surveyed online with the aims of trying to track when Marmorkrebs entered the North American pet trade, the ways in which it spread through the pet trade, and how widely distributed Marmorkrebs are throughout the continent. Marmorkrebs have been in the North American pet trade since at least 2004, with the number of people increasing every year. While many Marmorkrebs are sold through online sources, face-to-face personal contacts account for almost as many acquisitions. The increasing spread of Marmorkrebs through the pet trade increases the probability that Marmorkrebs will be released into North American ecosystems.

New records of Corbicula clams in French rivers.

Abstract: The aim of this paper is to present new data and review the current distribution of Corbicula spp. in France. Three morphotypes were recorded during the study - "round form", "light R form" and "saddle form". During April 2009, Corbicula spp. were found in several watercourses in France, including three rivers (Canal de la Somme, Oise and Vilaine) where the taxa were not previously reported. In addition, this is the first report of form S in the River Seine and, the first record of the "light R form" in the River Gard. Molluscs of the genus Corbicula are considered to be a well established alien species in large rivers.

Recent releases and dispersal of non-native fishes in England and Wales, with emphasis on sunbleak Leucaspius delineatus (Heckel, 1843)

Abstract: 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.

Preliminary assessment of feral goldfish impacts on ponds, with particular reference to native crucian carp

Abstract: Introductions of an Asian cyprinid, goldfish Carassius auratus, are known to pose a genetic threat to crucian carp Carassius carassius, which is native to northern parts of central and western Europe, including southeast England. However, there are no known studies in Europe of goldfish impacts on crucian carp growth and life-history traits, nor on the recipient ecosystems. The present study is the first such attempt, and compares the plants, invertebrates and fish biology (growth, condition, reproduction) in six ponds, two containing crucian carp only (allopatry), two containing goldfish only (allopatry), and two with both species (sympatry). Feral goldfish growth was greatest in sympatry with native crucian carp, whereas crucian carp growth was similar regardless of goldfish presence or absence. However, body condition (LK) and relative fecundity (per unit of body weight) of crucian carp was greatest in sympatry with feral goldfish. LK increased significantly with increasing water conductivity in goldfish but not in crucian carp, and LK was not related to pond invertebrate densities in either fish species. Differences in the plant and aquatic invertebrate communities observed in the study ponds could not be attributed to the introduction and establishment of goldfish, however non-native plant and invertebrate species were observed only in ponds containing goldfish. Differences in growth and condition between the two Carassius species does not appear to be due to differences in available food, so elevated somatic growth and reproductive output in crucian carp and faster growth in goldfish in sympatry may be due to non-dietary competitive interactions. The present preliminary study highlights the difficulties of assessing ‘real world’ impacts of non-native species on native species and ecosystems as well as the need for further study of feral goldfish impacts on European pond ecosystems in general and on native congener crucian carp in particular.

Long-term management of the invasive Pacifastacus leniusculus (Dana, 1852) in a small mountain stream

Abstract: Pacifastacus leniusculus (an invasive species in European water bodies) was detected for the first time in the Andalusia Region (S. Spain) in the year 2000. Since 2005, a continuous control management programme has been carried out by the Environmental Regional Government. Management efforts aimed to reduce the population size, to contain the dispersal and reduce the probability of deliberate translocation into other rivers caused by illegal captures. A combination of techniques was used, including crayfish traps, manual removal from artificial refuges and electrofishing. In the 2005-2009 period, 31 374 specimens were captured. The mean catch rate per worker and day declined from 30.4 ± 3.2 specimens in the first year to 9.8 ± 1.7 in the fourth year, therefore suggesting a sharp decrease in population size. Summer was the period of mating and maximum yields, whereas minimum yields were obtained in Winter, coinciding with egg incubation in burrows. The results obtained and the experience gained will provide essential baseline information for the future management of non-native crayfish in the region.

First Pacific record of the north Atlantic ascidian Molgula citrina - bioinvasion or circumpolar distribution?

Abstract: The small brooding ascidian Molgula citrina Alder and Hancock, 1848 has long been known as a common inhabitant of shallow waters on both sides of the north Atlantic on subtidal natural hard substrates and also as a fouler of floating docks. There are published records from the White Sea (NW Russia), but none from the north Pacific. In May and August 2008, a number of adult brooding Molgula sp. specimens were collected from floating docks at the small fishing village of Seldovia on the Kenai Peninsula at Kachemak Bay, Alaska. Morphologically these individuals exactly match Atlantic specimens of Molgula citrina in all characters that were examined. The unique constellation of characters for this species differentiates it from all other Molgula species, as noted by Van Name (1945). In addition, the full-length 18S and 28S rDNA sequences are identical for both the Alaska specimens and New England M. citrina. Is this a new invasion, or is M. citrina a northern circumpolar species that was somehow overlooked? If this new record indicates a natural distribution, why has it not been collected before? If it is a recent introduction, it is unlikely that M. citrina, an inhabitant of cold waters, could survive in sea chests of ships from the N. Atlantic arriving in Alaska via the Panama Canal, but the intriguing idea exists of transport from Atlantic to Pacific through the Northwest or Northeast Passages. As global warming diminishes the ice cover in this region, more and more ships are traversing the Northwest Passage across northern Canada as well as the NE Passage across northern Russia, representing significant new routes for anthropogenic transport of marine species. The tadpoles of this small brooder are retained for some time after hatching, resulting in an extremely short free larval life, but could survive as metamorphosed juveniles attached in sea chests or free-floating in ballast water. They have a wide temperature tolerance and once they metamorphose can live free-floating in sea water for some time. They become very sticky and will ultimately stick to whatever they contact. Thus they could conceivably live for many generations in sea chests and sustain a viable population from which to invade new habitats.

Management strategies for the zebra mussel invasion in the Ebro River basin

Abstract: Dreissena polymorpha has invaded seven rivers in the Ebro River basin (Spain) in the period 2001-2009. In this paper, we present a compilation of management strategies directed by the Ebro Hydrographic Confederation (CHE) with the aim of showing the different steps taken by this organisation to prevent the spread of this invader. These practical procedures are accompanied by diverse educational materials to inform and make people aware of the importance of this problem. The experience gained during these years has allowed the establishment of both an adequate sampling schedule and a sampling method for larval monitoring with the purpose of detection of zebra mussel populations. On the other hand, we have observed that mechanical cleaning and drying techniques are the physical control methods most frequently used by affected users in the Ebro basin, with use of chlorine as chemical method.

First record of the Japanese shore crab Hemigrapsus sanguineus (de Haan, 1835) (Brachyura: Grapsoidea: Varunidae) from the Black Sea

Abstract: 1* , Victor Niţa Abstract The Japanese shore crab Hemigrapsus sanguineus is recorded for the first time from a Black Sea locality: Tomis Marina in Constanţa, Romania. The suggested vector of introduction is as adults in the hull fouling of yachts. The species has not established and salinity requirements for larval development make it unlikely that it will ever establish in the Black Sea.

First record of oriental shrimp, Palaemon macrodactylus Rathbun, 1902 in Varna Lake, Bulgaria

Abstract: In September 2009 a non-native shrimp species was found at two sampling sites in Varna Lake, a brackish coastal water body connected to the Bulgarian Black Sea. Diagnosis based on morphological features confirmed that the examined individuals belonged to the species Palaemon macrodactylus Rathbun, 1902. All specimens found were ovigerous, 2+ year females suggesting the presence of a viable population in the system. Possible ways of introduction and community effects for Varna Lake are discussed.

Microbial hitchhikers: dynamics of bacterial populations in ballast water during a trans-Pacific voyage of a bulk carrier.

Abstract: Bacterial abundance, population dynamics and related environmental parameters were determined in ballast water during a trans- Pacific voyage from Japan to the west coast of Canada. Water samples were collected from four ballast tanks, two of which underwent mid-ocean exchange (MOE) and two that remained unexchanged (control). Bacterial abundances in the unexchanged tanks increased from ~6.4×10 8 cells/L on Day 0 to 1.8×10 9 cells/L on Day 7, whereas in MOE tanks, abundances increased from

Occurrence of the first non-indigenous ascidian Phallusia nigra Savigny, 1816 (Tunicata: Ascidiacea) in Greek waters.

Abstract: 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.

The killer shrimp, Dikerogammarus villosus (Sowinsky, 1894), is spreading in Italy

Abstract: 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.

Presence of the invasive red lionfish, Pterois volitans (Linnaeus, 1758), on the coast of Venezuela, southeastern Caribbean Sea

Abstract: We report the presence of the invasive Indo-Pacific red lionfish (Pterois volitans) in 23 localities of the Venezuelan coast, southeastern Caribbean Sea. This finding is based on ten specimens collected at Parque Nacional Archipielago de Los Roques (PNAR, Dependencias Federales), Playa Cal, Caraballeda and Puerto Carayaca (Estado Vargas) and 30 specimens observed in 18 localities of PNAR, Parque Nacional Morrocoy (Estado Falcon), Bahia de Cata, Ensenada de Cepe (Estado Aragua), Puerto Cruz, Chichiriviche de La Costa, Mamo, Catia La Mar, La Guaira, Macuto, Caraballeda (Estado Vargas) and Farallon Centinela (Dependencias Federales). The specimens were collected and observed from November 2009 to June 2010. This is the first published report documenting their occurrence in Venezuela.