Special issue: Proceedings of the 18th International Conference on Aquatic Invasive Species (ICAIS), April 21-25, 2013, Niagara Falls, Ontario, Canada
Edited by Calum MacNeil and Marnie Campbell
Published in September 2014
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Editorial
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Calum MacNeil and Marnie L. Campbell
The ‘grand scheme of things’: biological invasions, their detection, impacts and management (pp 195-196) |
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Research articles
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Jennifer K. Adams, Elizabeta Briski, Jeffrey L. Ram and Sarah A. Bailey
Evaluating the response of freshwater organisms to vital staining (pp 197-208) |
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The unintentional introduction of nonindigenous species by ballast water discharge is one of the greatest threats to biodiversity in freshwater systems.
Proposed international regulations for ballast water management will require enumeration of viable plankton in ballast water. In this study we analyze
the efficacy of vital stains in determining viability of freshwater taxa.
The efficacy of vital stains fluorescein diacetate (FDA) and FDA+5-chloromethylfluorescein diacetate (CMFDA) was evaluated with freshwater macroinvertebrates,
zooplankton, and phytoplankton. Macroinvertebrates were cultured in laboratory, while plankton were collected from Hamilton Harbour and ballast tanks
of commercial vessels. Organisms were subjected to various treatments (i.e., heat, NaClO, and NaOH) to establish efficacy of stains for viable
and non-viable organisms. No significant difference in accuracy rate was found between stains, regardless of treatment, within groups of organisms,
indicating that the addition of CMFDA is superfluous in the sample region studied. False positive errors, in which dead organisms fluoresced similarly
to live organisms, occurred in most groups and were significantly different between test groups. False positive error rates were 2.3% for phytoplankton,
20% for ballast water zooplankton, 35% for Hamilton Harbour zooplankton and 47% for macroinvertebrates.
Response to stains varied between taxonomic groups. Low (< 10%) false positive error rates were observed with phytoplankton, soft-bodied rotifers,
oligochaetes, and Bosmina spp., while rates between 20% and 50% were observed for Daphnia spp., Hexagenia sp., and Chironomus riparius.
False positive rates of copepods, Hyalella azteca, and Hemimysis anomala were between 70% and 100%. The FDA/FDA+CMFDA vital staining methods provide
useful tools for viability analysis of freshwater phytoplankton, soft-bodied invertebrates and zooplankton, and may be used for viability analysis of the ≥ 10 µm
to < 50 µm size fraction in compliance testing of ballast water. However, viability analysis of larger freshwater crustaceans with vital stains should
be undertaken with caution.
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Jeffrey L. Ram, Fady Banno, Richard R. Gala, Jason P. Gizicki and Donna R. Kashian
Estimating sampling effort for early detection of non-indigenous benthic species in the Toledo Harbor Region of Lake Erie (pp 209-216) |
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Toledo Harbor (Maumee River and Maumee Bay) is a “port of concern” for introduction of non-indigenous species into the Great Lakes due to the large amounts
of ballast water from outside the Great Lakes discharged at the port, the amenable habitat for many potential invasives, and the large amount of ballast water
transported from Toledo to other Great Lakes ports, making Toledo a potential source of invasives throughout the entire region. To estimate sampling intensity
needed to detect rare or new non-indigenous species, 27 benthic grab samples from 13 locations near Toledo Harbor were collected during autumn, 2010. Benthic
organisms were identified, and sampling intensity needed to detect rare or new non-indigenous species was evaluated via a Chao asymptotic richness estimator.
Morphological taxonomic criteria and cytochrome oxidase I (COI) sequence barcodes identified 29 different taxa (20 to species level) in the samples, including
six non-indigenous taxa (Branchiura sowerbyi, Bithynia tentaculata, Corbicula fluminea, Dreissena polymorpha, Dreissena bugensis,
Lipiniella sp.). While all the non-indigenous species had previously been reported in Lake Erie or nearby Ohio waters, several North American species
are not previously listed in Ohio. Richness estimates indicate that >75% of the benthic species in the area were encountered and that 90% of the species could
be detected with less than a doubling of collecting effort. Since sampling for this study occurred only in the autumn and detectable life stages of benthic organisms
may vary seasonally, additional species may be observed with more extensive sampling over a broader seasonal range.
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Katherine L. Prescott, Renata Claudi, Jeff Janik and Tanya Veldhuizen
Use of the calcite saturation index as an indicator of environmental suitability for dreissenid mussels (pp 217-224) |
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Determining environmental suitability for dreissenid mussel survival is important in managing water resources. The saturation index for calcite
(SIcalcite) was examined as a potential predictor of environmental suitability for dreissenids. SIcalcite was calculated for 500 lakes from Ontario,
Canada and Vermont and Wisconsin, USA. A lower limit of -0.9 was determined necessary for successful establishment of long-term mussel populations.
This limit was then applied to sites in the California State Water Project. When compared with using calcium alone or paired calcium and pH values,
SIcalcite was better at identifying environmental suitability at the extremes of calcium and pH ranges.
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Chris Wilson, Elizabeth Wright, Jenn Bronnenhuber, Francine MacDonald, Megan Belore and Brian Locke
Tracking ghosts: combined electrofishing and environmental DNA surveillance efforts for Asian carps in Ontario waters of Lake Erie (pp 225-231) |
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Effective control or eradication of invasive species depends on their early detection at low abundance to enable timely management responses.
In aquatic environments, the detection of rare or low-abundance species is challenging at best, and discriminating between detection failure (null)
and true absence (zero) can be difficult. We developed and applied environmental DNA (eDNA) markers to screen for occurrences of bighead carp
(Hypophthalmichthys nobilis), silver carp (H. molitrix), and grass carp (Ctenopharyngodon idella) in Ontario waters of Lake Erie,
Lake St. Clair, and tributaries, as part of ongoing efforts to prevent these Asian carps from becoming established in the Great Lakes. A network of 180
sites in nearshore and tributary habitats, selected based on perceived risk of fish access or habitat suitability, were sampled using both boat electrofishing
and/or eDNA sampling (948 water samples) throughout the 2012 open-water season. Electrofishing efforts did not capture any Asian carps, and no positive detections
of environmental DNA for any of these species were obtained using both conventional and quantitative PCR. These combined results suggest that these Asian carp species
are not yet established in Ontario waters of Lake Erie or Lake St. Clair, and highlight the value of combining conventional fisheries assessment and environmental DNA
surveillance for assessing the potential presence of invasive species in freshwater systems.
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Paul D. Champion, Mary D. de Winton and John S. Clayton
A risk assessment based proactive management strategy for aquatic weeds in New Zealand (pp 233-240) |
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Aquatic weeds are notoriously difficult to manage once established. This paper discusses a range of proactive management actions undertaken
by regulatory authorities based on the assessment of risk posed by those organisms using the Aquatic Weed Risk Assessment Model (AWRAM).
AWRAM scores potential risk characters such as habitat range, ability to displace other species, seed and vegetative propagule output,
dispersal mechanisms, potential economic and environmental impacts, potential distribution and ease of control. Species with the largest
sum of risk character scores are regarded as the worst potential aquatic weeds and AWRAM provides a decision support tool for management agencies.
Management actions include prevention of deliberate introduction into New Zealand and subsequent spread within that country, as well as eradication
programs targeting high-impact, low-incidence aquatic weeds species. Progress to date has been the exclusion from sale and distribution of 29 potential
aquatic weeds and the ban from importation of a further 10 species. Current regulations have effectively ceased legal importation of aquatic plants
into New Zealand, but evidence of illegal importation provides concern. Six freshwater weeds have been eradicated nationally and central and regional
government agencies have initiated eradication programs for a further 13 aquatic weeds, with additional species managed in this way at a regional or island level.
These proactive management activities are effective methods to achieve elimination or reduction of both propagule and colonization pressure of high-risk aquatic weeds,
thereby reducing the likelihood of those species becoming widespread problems in the future.
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Robert E. Baier, Robert L. Forsberg, Anne E. Meyer and Dean C. Lundquist
Ballast tank biofilms resist water exchange but distribute dominant species (pp 241-244) |
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Shipping in the Laurentian Great Lakes includes numerous “lakers” and a group of international vessels arriving
via the St. Lawrence Seaway. It was expected that ballast water exchange techniques, or eventual volumetric ballast
water treatment, would eliminate the risks of transfer of ballast tank nuisance aquatic and aerosol organisms to Great
Lakes ports and other parts of the world. New and important information is that ballast water exchanges and current ballast
water treatments are not effective in destroying biofilms on tank walls and sediments that provide living micro-organisms
for new biofilms and bioaerosols. Our Ballast Organic Biofilm (BOB) studies of around-the-world ships associated with multiple
ballasting events in the continuous presence of BOB samplers showed that dominant microorganisms are acquired and persist,
and can be spontaneously transferred to fresh surfaces and also delivered as bioaerosols from discharged ballast water plumes.
This communication uses such studies to infer that a port-based ballast tank water-exchange and cleaning procedure can mitigate
such biofilm risks to health and existing biodiversity. A useful site would be the Port of Buffalo, just opposite the Welland
Canal entrance for international shipping to the upper Great Lakes.
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Elizabeta Briski, Robert Dallas Linley, Jennifer K. Adams and Sarah A. Bailey
Evaluating efficacy of a ballast water filtration system for reducing spread of aquatic species in freshwater ecosystems (pp 245-253) |
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Biological invasions by non-indigenous species are considered a leading threat to biodiversity, with prevention being a key management strategy.
Consequently, numerous commercial ballast water treatment systems have been, or are being, developed to prevent future aquatic invasions. However,
most treatment systems are being designed for the many vessels undertaking long transoceanic voyages in marine waters rather than the relatively
few vessels operating on short voyages in freshwater, such as those in the Laurentian Great Lakes. Here we conduct testing of the biological efficacy
of a 40 µm ballast water filtration unit through shipboard trials. We test the hypotheses that i) filtration will significantly reduce abundance
of zooplankton greater than 50 µm in size but not phytoplankton 10 to 50 µm in size; ii) filtration will reduce zooplankton abundances in ballast
water below International Maritime Organization discharge standards, but not those of phytoplankton; and iii) filtration will alter the community
composition of zooplankton, non-randomly reducing invasion risk of larger taxa. During the summer of 2012, three shipboard trials were conducted.
Ballast water samples were collected using a before-after experimental design. Our study showed that filtration significantly reduced abundance
of copepods and cladocerans, but not of juvenile dreissenid veligers and rotifers. Contrary to our expectation, phytoplankton densities were also
significantly lower after the treatment. Overall, ballast water treated during our tests would not meet proposed international discharge standards.
Filtration altered relative abundance of zooplankton, but did not reduce introduction risk of any taxonomic group due to the small juvenile stages
and dormant eggs which passed through the treatment. While we do not rule out filtration as a ballast water treatment option for zooplankton in the future,
our tests indicate further development is required for meaningful reduction of invasion risk.
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Kiley Best, Cynthia H. McKenzie and Cyr Couturier
Investigating mitigation of juvenile European green crab Carcinus maenas from seed mussels to prevent transfer during Newfoundland mussel aquaculture operations (pp 255-262) |
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The mussel aquaculture industry has raised concerns following the discovery of green crab Carcinus maenas in Placentia Bay Newfoundland in August 2007.
Post-larval green crabs have been found in feral mussel beds in high densities in Europe. If this is true for other green crab populations, mussel seed transfers
from Placentia Bay could provide a vector for post-larval juvenile crab transfer to other areas like Notre Dame Bay where provincial mussel aquaculture is concentrated.
Green crab is currently not found in this area of Newfoundland. Newly settled green crab juveniles were collected and used in a series of lab scale mitigation trials.
Crab and seed mussels were exposed to thermal shocks applicable and feasible for mussel seed management in Placentia Bay. Crab mortality was measured in the treatments
and seed mussels were monitored for stress response using the lysosomal destabilization assay. Exposure to heated salt water to 45, 50 and 55°C was effective in culling
juvenile green crab while causing minimal stress to mussel seed. The method can be employed in mussel seed management and transfer operations where there are concerns
related to potential introductions of hitch-hiking green crab.
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Susan Pasko and Jason Goldberg
Review of harvest incentives to control invasive species (pp 263-277) |
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From nutria to lionfish, recent interest has grown in ways to encourage the harvest and use species as a means of controlling or eradicating invasive populations.
If used properly, incentivizing and encouraging public or commercial harvest represents a significant opportunity to support ecosystem and natural resource management
while simultaneously boosting economic development and environmental awareness. However, if used incorrectly, negative consequences such as further spread can occur.
Success depends on interactions between the species, its invasive range, and socioeconomic factors, yet little guidance is available on how to use incentivized
harvest as an effective management tool. This paper reviews the biological, ecological, human health, and socioeconomic factors involved in invasive species
incentive programs. We also offer recommendations to assist in development and implementation of a successful harvest program.
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Sara Meehan, Bridget Gruber and Frances E. Lucy
Zebra mussel control using Zequanox® in an Irish waterway (pp 279-286) |
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Due to the invasion of zebra and quagga mussels in European and North American waters, there is a need for an environmentally
benign mussel control method to replace chlorine and other currently used control products. Zequanox® is a natural product comprised
of Pseudomonas fluorescens strain CL145A, which effectively controls zebra and quagga mussels. The objective of this study was
to demonstrate an effective method of zebra mussel control in inland waterways using Zequanox. Water quality was monitored to determine
any negative impacts and to observe product dispersion. A curtain made of an impermeable material was placed in the Grand Canal at Tullamore
Harbour sealing off two 8 x 0.5 m sections of canal wall under the bridge, and a control site was chosen further down the docking area.
Both sections were treated with Zequanox at a concentration of 150 mg active substance/L for an 8 hour treatment period. Water quality
was monitored in the treatment area and in the selected control area before, during, and after treatment. Naturally settled and seeded
adult zebra mussels were observed for mortality in the treatment and control areas and juveniles were monitored for survival in both
the treatment and control areas. Naturally settled adult mussel numbers were reduced by approximately 46% in treatment side 1, and 65%
in treatment side 2, seeded adult mussel mortality reached 75% in treatment side 1 and 56% in treatment side 2. These results demonstrate
that under the optimum conditions Zequanox effectively controls zebra mussels in open water.
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Sarah Nienhuis, Tim J. Haxton and Tal C. Dunkley
An empirical analysis of the consequences of zebra mussel invasions on fisheries in inland, freshwater lakes in Southern Ontario (pp 287-302) |
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With increasing human use of North American inland lakes for recreational purposes, there is a greater probability of the incidental transfer
and introduction of aquatic invasive species within them. This raises concern over the potential ecological and economic impacts that invasive
species could have in these highly valued freshwater ecosystems. In this study, we focus our interests on 63 inland lakes distributed across
the Southern Ontario landscape in order to evaluate whether concerns are warranted over potential adverse impacts of a well-known aquatic
invasive species (the zebra mussel (Dreissena polymorpha)) on native fish assemblages and targeted game species (i.e., walleye
(Sander vitreus), smallmouth bass (Micropterus dolomieu), lake trout (Salvelinus namaycush), and northern pike (Esox lucius)).
Through the analysis of a comprehensive and multivariate dataset comprising lake morphometric, water chemistry, fish assemblage, fish metric, and zooplankton
haul data, we examined the potential consequences of zebra mussel invasions in inland lakes. It was found that condition, growth, and relative abundance
of some of the most highly valued game fish in inland lakes significantly varies among lakes with and without zebra mussel, though the nature of such effects
differed for each of the fish species examined. In addition, it was shown that the species composition (i.e., identity and relative abundance) of active,
large-bodied fish assemblages within a lake can indicate zebra mussel presence/absence with a high degree of certainty. Finally, while correlations between
zebra mussel presence and the richness, abundance, growth, and condition of certain fish species were found, the results of this study indicate that
the potential consequences of this well-known aquatic invader to fisheries in inland lakes may be less dramatic than those reported within the Great Lakes.
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Calum MacNeil
“The pump don’t work, ‘Cause the vandals took the handles”; why invasive amphipods threaten accurate freshwater biological water quality monitoring (pp 303-307) |
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The 2010 invasion of Great Britain by the eastern European ‘killer shrimp’ Dikerogammarus villosus (Crustacea: Amphipoda) was just the latest
of several amphipod invasions of British freshwaters and just one of many amphipod invasions occurring on a global scale. Using examples of previous
invasions of other amphipods, Gammarus pulex and Crangonyx pseudogracilis in The Isle of Man and Northern Ireland, I show that these
invaders have the potential to undermine the accuracy of ecological assessment programmes of freshwater, such as those employed in the Water Framework
directive (WFD) in Europe and similar schemes used by environmental protection agencies all over the world. Such assessment programmes invariably rely
on biological water quality monitoring using biotic indices derived from resident macroinvertebrate assemblages. All three amphipod invaders can greatly
undermine accurate water quality biomonitoring in river systems. This can be by invasive amphipods predating upon and/or outcompeting resident macroinvertebrates
and thus radically altering resident biodiversity and assemblage structure. This can also occur because these invaders tend to be more physico-chemically tolerant
than the resident taxa they are replacing and this greater tolerance of poor organic chemical water quality is not acknowledged in biotic scoring indices.
A way forward would be to measure the biological pressure invaders may exert in a biocontamination index or similar, while simultaneously carrying out routine
water quality monitoring using biotic indices.
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