Published in February 2013
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Editorial
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Marnie L. Campbell
The pointy end of the stick: managing biological invasions (pp 1-2) |
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Viewpoint
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Stelios Katsanevakis, Piero Genovesi, Samy Gaiji, Helene Nyegaard Hvid, Helen Roy, Ana Luísa Nunes, Francisco Sánchez Aguado,
Konstantins Bogucarskis, Bos Debusscher, Ivan Deriu, Colin Harrower, Melanie Josefsson, Frances E. Lucy, Agnese Marchini, Gareth Richards, Teodora Trichkova,
Sonia Vanderhoeven, Argyro Zenetos and Ana Cristina Cardoso
Implementing the European policies for alien species – networking, science, and partnership in a complex environment (pp 3-6) |
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The European Commission has recognized the need for more stringent action to manage biological invasions and has committed to develop a dedicated legislative instrument.
Under this upcoming legislation, European countries and their relevant institutions will have additional obligations and commitments in respect to invasive alien species.
In September 2012, the European Commission’s Joint Research Centre (JRC) launched the European Alien Species Information Network (EASIN) to facilitate the exploration
of existing alien species information from distributed sources and to assist the implementation of European policies on biological invasions. Subsequent to the launching
of EASIN, there was an evident need to define its niche within a complex environment of global, European, regional and national information systems. Herein we propose
an organizational chart clearly defining the role of each actor in this framework, and we emphasize the need for collaboration in order to effectively support EU policies.
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Research articles
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Amy L. Trenouth and Marnie L. Campbell
Perceptions of ecological risk associated with introduced marine species in marine protected areas (pp 7-24) |
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The perception of ecological risks (impact and acceptability) associated with introduced marine species (IMS), what demographic variables
influence those perceptions, respondent’s knowledge of IMS, and people’s support for controlling introduced marine species impacts on
the marine environment was explored at three locations in Western Australia: Ningaloo Reef Marine Park, Rottnest Island Marine Reserve,
and Hamelin Bay. Recognition that introduced marine species are an issue at state, national and international levels exists; yet often
marine protected area management plans do not reflect this recognition. Therefore, we hypothesise that there is a lack of translation
of concern regarding introduced marine species as a risk into tactical objectives within marine protected area management plans. This
may be due to low stakeholder perceptions of the risk posed by introduced marine species. Survey respondents had a high level (89%)
of self-rated awareness of introduced marine species and they also indicated (93%) a willingness to support management interventions
to prevent, or control the spread of introduced marine species in Western Australia.
Our results also indicate that gender (males) and age (18–45 age group) influenced respondents’ perception of risk (impact) of IMS,
yet no examined demographic variables influenced respondents acceptability of risk. Furthermore, knowledge of introduced marine species,
education level, and income variables did not influence respondents’ perception of risk (impact or acceptability). Understanding demographic
characteristics that influence participants perceptions related to introduced marine species can be useful for targeted, educational initiatives
to reduce the likelihood of IMS incursions. This begins to smooth the way for management to proactively develop and implement policies that
are necessary to more fully protect the Western Australian marine environment.
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Jochen Vandekerkhove, Ana Cristina Cardoso and Philip J. Boon
Is there a need for a more explicit accounting of invasive alien species under the Water Framework Directive? (pp 25-36) |
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Through ratification of the Water Framework Directive (WFD), EU Member States committed themselves to a pressure-based assessment of the ecological status
of their water bodies. Invasive alien species (IAS) constitute a major pressure in many aquatic ecosystems, yet are not explicitly accounted for by the majority
of WFD assessment methods. Most Member States argue that no explicit assessment of IAS is required, assuming that significant IAS pressures will affect the WFD
biological quality elements (BQEs), and be detected by generic WFD status assessments. We tested this assumption for a selection of country-by-surface-water
category combinations, covering nearly 40,000 water bodies. For each of the combinations, the pressure by high-impact IAS is higher in water bodies with ecological
status varying from bad to moderate than in water bodies in good or high ecological status. Most high-impact IAS show strong associations with low status class categories.
Of the 17 most frequently occurring high-impact IAS, only Mustela vison (Schreber, 1777) and Potamopyrgus antipodarum (Gray, 1853) are disproportionately
frequent in high status water bodies. The sensitivity of WFD methods varies across BQEs, with macrophyte-based methods showing a consistently high sensitivity to IAS
pressures. However, significant pressures are observed in a number of high status water bodies. This points to a need for further optimization of existing methods
so that they address the full range of pressures exerted by IAS.
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Stelios Katsanevakis, Francesca Gatto, Argyro Zenetos and Ana Cristina Cardoso
How many marine aliens in Europe? (pp 37-42) |
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In the framework of the European Alien Species Information Network (EASIN; http://easin.jrc.ec.europa.eu/), an inventory of marine alien species in Europe
was created by critically reviewing existing information in 34 global, European, regional and national databases. In total, 1369 marine alien species have
been reported in the European seas (including 110 cryptogenic and 139 questionable species); this is a substantial increase from the 737 species previously
reported in 2009 based on the DAISIE (Delivering Alien Invasive Species Inventories for Europe; http://www.europe-aliens.org) dataset. Most of the reported
species were invertebrates (63.3%), followed by chromists (13.7%), vertebrates (11.6%), and plants (10.1%). Mollusca is the most numerous phylum, followed
by Arthropoda, Chordata, and Annelida. The countries with the highest reported numbers of marine alien species were Israel, Turkey, Italy, France, Egypt and Greece.
A reporting bias is evident as efforts for monitoring and reporting alien species vary among countries.
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Anne K. J. Wittfoth and Michael L. Zettler
The application of a Biopollution Index in German Baltic estuarine and lagoon waters (pp 43-50) |
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This paper assesses the status of three German Baltic estuarine and lagoon waters with respect to invasive species (macrozoobenthos) and their impact.
A Biological Pollution Index was applied and evaluated. Overall 130 macrozoobenthic species were identified, 17 of which were aquatic alien species.
The Szczecin Lagoon had the highest number of invasive species (13). Most species were of Pontocaspian origin; inland waterways are likely to play
a significant role in their migration. According to the Biological Pollution Index Level (BPL) this lagoon was ‘moderately influenced’ by invasive species.
Warnow Estuary had 11 invasive species; their origin noted generally from North-America, suggesting shipping traffic as the major distribution vector;
invasive species had the same BPL as in the Szczecin Lagoon. In the Darß Zingst Bodden Chain only 6 invasive species were observed, having the highest
relative abundance (9-71%). Furthermore, this area had the highest BPL of all three areas, i.e. a strong negative impact. The BPL required a lot of data
(including historical) and some ratings were subjective and comparisons with other areas assessed were difficult and often impossible. Due to these limitations,
it is suggested that the BPL should only be used with restrictions as a universal assessment tool for invasive species in the estuarine and lagoon waters of the Baltic Sea.
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S. Mark Nelson and Fred Nibling
Monitoring invasive quagga mussels, Dreissena rostriformis bugensis (Bivalvia: Dreissenidae), and other benthic organisms in a western US aqueduct (pp 51-59) |
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A quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) invasion of an aqueduct in Arizona was monitored from 2007 – 2011 using colonization substrates.
As numbers increased, a filtering-collector caddisfly (Smicridea fasciatella McLachlan, 1871) declined significantly in abundance. After two years of colonization,
freshwater sponges were detected and associated with a decline in D. r. bugensis numbers. Periphyton biomass increased considerably on substrates; perhaps partially,
the result of decreased turbidity. Aqueduct biofoulers could have major impacts on costs associated with aqueduct maintenance. From an operations viewpoint, mussels are
undesirable due to flow restriction associated with increased friction. Augmented sponge and periphyton biomass may also influence aqueduct operations and efficiencies.
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Wook Jin Choi, Shawn Gerstenberger, Robert F. McMahon and Wai Hing Wong
Estimating survival rates of quagga mussel (Dreissena rostriformis bugensis) veliger larvae under summer and autumn temperature regimes
in residual water of trailered watercraft at Lake Mead, USA (pp 61-69) |
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On 6 January 2007, invasive quagga mussels [Dreissena rostriformis bugensis (Andrusov, 1897)] were discovered in the Boulder Basin of Lake Mead, Nevada,
a popular site for recreational boating in the southwestern United States. Recreational watercraft are considered a primary vector for overland dispersal of quagga mussel
veliger larvae between water bodies. Thus, effective decontamination of veligers in residual water carried by trailered recreation boats is critical to controlling
this species’ spread. The survival rate of quagga mussel veligers was measured during exposure to environmental temperature conditions mimicking those experienced
in the residual water of trailered vessels during warm summer and cooler autumn months in the semi-arid southwestern United States. Under warm summer conditions,
quagga mussel veligers survived approximately five days while under cooler autumn conditions they survived 27 days. When tested under autumn temperature conditions
veliger survival times increased with increased level of larval development. The results suggested a greater likelihood of veliger transport in the residual water
of trailered watercraft during autumn months. The results indicated that presently recommended vessel quarantine times to kill all externally attached juvenile
and adult dreissenid mussels prior to launching in an uninfested water body should be increased to generate 100% veliger mortality in residual water unable to be fully
drained from the internal areas of watercraft.
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Daniel P. Molloy, Denise A. Mayer, Michael J. Gaylo, Lyubov E. Burlakova, Alexander Y. Karatayev,
Kathleen T. Presti, Paul M. Sawyko, John T. Morse and Eric A. Paul
Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae) (pp 71-79) |
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In an effort to develop an efficacious and environmentally safe method for managing zebra mussels (Dreissena polymorpha) and quagga mussels
(Dreissena rostriformis bugensis), we initiated a research project investigating the potential use of bacteria and their natural metabolic products
as biocontrol agents. This project resulted in the discovery of an environmental isolate lethal to dreissenid mussels, Pseudomonas fluorescens
strain CL145A (Pf-CL145A). In previous published reports we have demonstrated that: 1) Pf-CL145A’s mode of action is intoxication (not infection);
2) natural product within ingested bacterial cells lyse digestive tract epithelial cells leading to dreissenid death; and 3) high dreissenid kill rates (>90%)
are achievable following treatment with Pf-CL145A cells, irrespective of whether the bacterial cells are dead or alive. Investigating the environmental safety
of Pf-CL145A was also a key element in our research efforts, and herein, we report the results of non-target trials demonstrating Pf-CL145A’s high specificity
to dreissenids. These acute toxicity trials were typically single-dose, short-term (24-72 h) exposures to Pf-CL145A cells under aerated conditions at concentrations
highly lethal to dreissenids (100 or 200 mg/L). These trials produced no evidence of mortality among the ciliate Colpidium colpoda, the cladoceran
Daphnia magna, three fish species (Pimephales promelas, Salmo trutta, and Lepomis macrochirus), and seven bivalve species
(Mytilus edulis, Pyganodon grandis, Pyganodon cataracta, Lasmigona compressa, Strophitus undulatus, Lampsilis radiata,
and Elliptio complanata). Low mortality (3-27%) was recorded in the amphipod Hyalella azteca, but additional trials suggested that most, if not all,
of the mortality could be attributed to some other unidentified factor (e.g., possibly particle load or a water quality issue) rather than Pf-CL145A’s dreissenid-killing
natural product. In terms of potential environmental safety, the results of these invertebrate and vertebrate non-target trials are encouraging, but it would be
unrealistic to think that dreissenids are the only aquatic organisms sensitive to Pf-CL145A’s dreissenid-killing natural product. Additional testing is needed to better
define Pf-CL145A’s margin of safety by identifying the sensitivity of other susceptible organisms. The results of these non-target safety trials – in combination with
equally promising mussel control efficacy data – have now led to Pf-CL145A’s commercialization under the product name Zequanox®, with dead cells as the product’s active
ingredient. The commercial availability of only dead-cell Zequanox formulations will eliminate the risk of any possible non-target infection by Pf-CL145A, further
reducing environmental concerns. During the non-target project reported herein, the limited quantities of Pf-CL145A cells that we were able to culture severely restricted
the number and size of our trials. In contrast, the availability of Zequanox will now greatly expand the opportunities for non-target testing. The trials reported
herein – exposing non-target organisms under aerated conditions to unformulated, laboratory-cultured cells – clearly point to Pf-CL145A’s potential for high host
specificity, but non-target trials with Zequanox – using Pf-CL145A cells cultured, killed, and formulated using industrial-scale protocols – will be even more
important as they will define the non-target safety limits of the actual commercial products under a wide range of environmental conditions.
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Ahmed Siah and Patricia McKenna
Rapid detection assay for the invasive vase tunicate, Ciona intestinalis, using loop-mediated isothermal
amplification combined with lateral flow dipstick (pp 81-86) |
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Invasive tunicate species threaten the shellfish aquaculture industry not only in Prince Edward Island (PEI) but also nationally and worldwide.
Rapid screening tools for water samples are crucial for the efficient management of aquatic invasive species. This project aims to develop a rapid
detection assay capable of identifying larvae of the vase tunicate, Ciona intestinalis, in seawater. In this study, a loop-mediated isothermal
amplification (LAMP) method has been developed to detect the 18S ribosomal DNA extracted from C. intestinalis. This assay was performed
in three steps: 1) a DNA extraction step using a direct lysis buffer, 2) an amplification step using a heating block, and 3) a detection step using
a lateral flow dipstick. The sensitivity of the assay was estimated at one larva spiked in 100 L of seawater and the turnaround time of the assay was
assessed at 80 min including the lysis step. Given the advantages of this assay such as rapid amplification, ease of use and detection, it could be
implemented for monitoring bays and estuaries. In the future, rapid diagnostic assays will constitute a new generation of diagnostic platforms
enabling the early detection of non-indigenous invasive species.
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