WorldWideScience

Sample records for zebra mussel fouling

  1. Strategies to control zebra mussel fouling at Kewaunee Nuclear Power Plant

    International Nuclear Information System (INIS)

    Schwartz, D.; Kasper, J.R.; Pisani, W.

    1992-01-01

    The zebra mussel, Dreissena polymorpha, is currently infesting the Great Lakes. First discovered in Lake St. Clair, it is now widespread in Lakes Erie and Ontario. The initial efforts relating to zebra mussel control at Wisconsin Public Service Corporation's (WPSC) Kewaunee Nuclear Power Plant (KNPP) precipitated from the Nuclear Regulatory Commission's (NRC) Generic Letter 89-13 regarding fouling of service water (SW) systems at nuclear power plants. In the summer of 1990, Stone and Webster Engineering Corporation (Stone and Webster) was contracted to perform an evaluation of known problems within the SW system. The purposes of the study were to evaluate the actual and potential magnitude of these problems, to evaluate corrective actions to resolve the problems, and to prepare recommendations which would adequately address the issues. Two of the recommendations of this study were to continue a zebra mussel monitoring program which WPSC had already implemented and to evaluate various biocide injection programs should one be required for zebra mussel control. The concern of utilities operating power stations which use waters infested with zebra mussels as their source of cooling and/or makeup water is that mussels (both adults and veligers) will enter plant water systems and foul piping and heat exchangers. This type of fouling can restrict flow through piping, process equipment, and heat exchangers. This type of fouling can restrict flow through piping, process equipment, and heat exchangers, thereby increasing head losses and reducing heat transfer capabilities. The greatest concern in that fouling of this type is within safety-related piping and equipment that are components of service water systems at nuclear power plants

  2. Zebra mussel monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hennagir, T.

    1994-01-01

    In less than a decade, zebra mussels have become the latest environmental scourge to plague the North American power industry. Infestations in the Great Lakes region have already reached natural disaster proportions. The invasion shows little sign of subsiding; Michigan's inland waters are the next most likely threatened area. In the southern United States, the mussles' migration has extended about 50 miles deeper than experts had originally predicted. By the year 2000, zebra mussel monitoring and control efforts will cost business and industry $5 billion, according to the federal Aquatic Nuisance Prevention and Control Act of 1990. Estimates of more than $1 million to control mussel fouling are projected for the Great Lakes area alone. While small independent hydropower stations are not as susceptible to zebra mussles as coal or nuclear facilities, there is cause for concern. Infestations can quickly foul hydropower plant components, hampering equipment operation and reducing facility efficiency. In extreme cases, leaving the mussels unchecked can result in stoplog gate flow blockage or false water level gauge readings. Advance prevention is often an effective first-line of defense against this troublesome, rapidly spreading and extremely prolific mollusk. Mussel monitoring efforts should begin a year in advance of when zebra mussels are expected to appear in a given location. Hydropower facility components that come into contact or rely exclusively on raw water are at greatest risk, as are other external components such as embayment walls, screens, trashracks and fish ladders.

  3. Environmentally Safe Control of Zebra Mussel Fouling

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Molloy

    2008-02-29

    The two primary objectives of this USDOE-NETL contract were successfully achieved during the project: (1) to accelerate research on the development of the bacterium Pseudomonas fluorescens strain CL145A (Pf-CL145A) as a biocontrol agent for zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis)--two invasive freshwater bivalve species that are infesting water pipes in power plants; and (2) to identify a private-sector company that would move forward to commercialize Pf-CL145A as a substitute for the current polluting use of biocide chemicals for control of these dreissenid mussels in power plant pipes.

  4. The zebra mussel: US utility implications

    International Nuclear Information System (INIS)

    McMahon, R.F.

    1990-11-01

    Dreissena polymorpha, the freshwater macrofouling zebra mussel, was introduced to Lake St. Clair, near Detroit, Michigan, in 1985. It has since spread throughout Lake Erie. Its planktonic veliger larval stage disperses on water currents and adults are transported by human and natural vectors, making it likely to spread throughout most of the United States and southern Canada except for the southwestern and southern United State, where summer water temperatures are above tolerated levels. Veligers enter raw water systems on intake currents to settle and grow to adults attached by secreted byssal threads to hard surfaces. Accumulations of adults impede flow, aggravate sedimentation and corrosion, and foul small-diameter components. Settlement occurs at flow velocities less than 1.5--2.0 m/sec. Mussels can reduce effective pipe diameters and foul intake structures, steam condensers, heat exchangers, fire protection systems, and cooling tower basins. Establishment of mussels in raw water systems should be prevented because subsequent removal is difficult and expensive. Mitigation procedures include manual removal, robotic cleaning, thermal backwashing, water jetting, application of molluscicides, and possibly line pigging and acidic chemical cleaning. Control technologies include oxidizing and non-oxidizing molluscicides, robotic cleaning, shell strainers, exposure of veligers to high voltage electrical fields, thermal backwashing and sand-filtration. The United States power industry can utilize extensive European experience with this species and domestic experience with the Asian clam in its development of effective controls for zebra mussel fouling

  5. Zebra Mussel Antifouling Activity of the Marine Natural Product Aaptamine and Analogs

    Science.gov (United States)

    Diers, Jeffrey A.; Bowling, John J.; Duke, Stephen O.; Wahyuono, Subagus; Kelly, Michelle; Hamann, Mark T.

    2016-01-01

    Several aaptamine derivatives were selected as potential zebra mussel (Dreissena polymorpha) antifoulants because of the noteworthy absence of fouling observed on Aaptos sponges. Sponges of the genus Aaptos collected in Manado, Indonesia consistently produce aaptamine-type alkaloids. To date, aaptamine and its derivatives have not been carefully evaluated for their antifoulant properties. Structure–activity relationship studies were conducted using several aaptamine derivatives in a zebra mussel antifouling assay. From these data, three analogs have shown significant antifouling activity against zebra mussel attachment. Aaptamine, isoaaptamine, and the demethylated aaptamine compounds used in the zebra mussel assay produced EC50 values of 24.2, 11.6, and 18.6 μM, respectively. In addition, neither aaptamine nor isoaaptamine produced a phytotoxic response (as high as 300 μM) toward a nontarget organism, Lemna pausicostata, in a 7-day exposure. The use of these aaptamine derivatives from Aaptos sp. as potential environmentally benign antifouling alternatives to metal-based paints and preservatives is significant, not only as a possible control of fouling organisms, but also to highlight the ecological importance of these and similar biochemical defenses. PMID:16718618

  6. Hudson River Unionids and Zebra Mussels: The Beginning of the End or the End of the Beginning?

    Science.gov (United States)

    Strayer, D. L.; Malcom, H. M.

    2005-05-01

    The invasion of the Hudson River estuary by zebra mussels was followed by steep declines (77 to >99.7%) in populations of all species of native bivalves between 1992 and 1999. Body condition of all unionids, and growth and recruitment of young unionids also declined significantly. Declines in population size and body condition were correlated primarily with the filtration rate of the zebra mussel population, not with fouling of native bivalves by zebra mussels. Samples taken since 2000, however, have shown that populations of all 4 common native bivalves have stabilized or even recovered, although the zebra mussel population has not declined. The mechanisms underlying this apparent reversal of fortune are not clear: recruitment and growth of young mussels have showed limited recovery, but body condition of adults has not. We found no evidence that spatial refuges contributed to this reversal of population declines. Simple statistical models project now that native bivalves may persist at population densities about an order of magnitude below their pre-invasion densities.

  7. Environmental DNA mapping of Zebra Mussel populations

    Science.gov (United States)

    Amberg, Jon J.; Merkes, Christopher

    2016-01-01

    Environmental DNA (eDNA) has become a popular tool for detecting aquatic invasive species, but advancements have made it possible to potentially answer other questions like reproduction, movement, and abundance of the targeted organism. In this study we developed a Zebra Mussel (Dreissena polymorpha) eDNA protocol. We then determined if this assay could be used to help determine Zebra Mussel biomass in a lake with a well-established population of Zebra Mussels and a lake with an emerging population of mussels. Our eDNA assay detected DNA of Zebra Mussels but not DNA from more than 20 other species of fish and mussels, many commonly found in Minnesota waters. Our assay did not predict biomass. We did find that DNA from Zebra Mussels accumulated in softer substrates in both lakes, even though the mussels were predominately on the harder substrates. Therefore, we concluded that eDNA may be useful to detect the presence of Zebra Mussels in these lakes but our assay/approach could not predict biomass.

  8. Zebra mussels anchor byssal threads faster and tighter than quagga mussels in flow.

    Science.gov (United States)

    Peyer, Suzanne M; McCarthy, Alice J; Lee, Carol Eunmi

    2009-07-01

    While the invasive zebra mussel Dreissena polymorpha has rapidly spread throughout the Great Lakes and inland waterways, it is being displaced by the quagga mussel Dreissena bugensis in shallow water habitats. However, zebra mussels remain dominant in areas with higher water velocity. We hypothesized that the persistence of zebra over quagga mussels in habitats with higher water velocity might result from greater rate and strength of byssal thread attachment. We examined whether zebra mussels relative to quagga mussels have: (1) higher byssal thread synthesis rate, (2) lower dislodgment in flow and (3) greater mechanical force required for detachment from substrate. Specifically, we examined byssal thread synthesis rate and dislodgment of both species in response to water velocities of 0, 50, 100 and 180 cm s(-1). Byssal thread synthesis rate was significantly higher for zebra than for quagga mussels at all velocities. Dislodgment from the substrate increased for both species with increasing velocity but was significantly lower for zebra than for quagga mussels. We also tested the mechanical force to detach mussels after short (32 h) and long (two and three months) periods of attachment on hard substrate. Detachment force was significantly higher for zebra than for quagga mussels only after short-term attachment. Higher byssal thread synthesis rate in zebra mussels was a likely factor that minimized their dislodgment in flow and increased short-term attachment strength. Differences in byssal thread synthesis rate between the two species might partly account for the ability of zebra mussels to maintain dominance over quagga mussels in habitats with high velocities.

  9. An overview of filtration methods that can provide protection from the macrofouling zebra mussel at hydroelectric facilities

    Energy Technology Data Exchange (ETDEWEB)

    Smythe, A.G.; Short, T.M. [Acres International Corp., Amherst, NY (United States)

    1995-12-31

    The non-indigenous freshwater zebra and quagga mussels (Dreissena, spp.) threaten to foul freshwater conduits throughout much of the United States and southern Canada. Initially, many electric facilities within the lower Great Lakes drainage were fouled. More recently, other systems both in and out of the Great Lakes, have been exposed to infested water facilitated by canals and boat traffic and impacted by the mussels. Mussels have clogged conduits and fouled equipment and monitoring sensors in relatively distant regions including the Hudson River, the Mississippi River south to New Orleans, and the Arkansas River into Oklahoma. Chemicals can effectively control the mussels, however, filtration methods promise to be a relatively cost effective, environmentally safe alternative control approach. Information on traditional filtration methods will be presented in this paper along with recent research results for in-line filters.

  10. Research continues on zebra mussel control

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Researchers are working on many fronts to learn methods for controlling and combatting zebra mussels, a species of mussel that can attach to the inside of water intakes at hydroelectric and thermal power plants, and can reduce or block water flow. Biologists at the University of Toledo in Ohio report that compounds from the African soapberry plant called lemmatoxins are lethal to zebra mussels. In laboratory tests, researchers have determined 1 to 2 milligrams of purified lemmatoxins per liter will kill the mussels. In field tests, biologist Harold Lee flushed water through a mussel-infested pipe. He found that the berry extract killed mussels in four to eight hours, making continuous treatment of water intake pipes unnecessary, according to a report in New Scientists. The University of Toledo participated in another project, funded by the American Water Works Association Research Foundation. That project team included the cities of Toledo and Cleveland, Ohio, Finkbeiner, Pettis ampersand Strout, Ltd. consulting engineers, and researchers from Ohio's Case Western Reserve University. The team identified a chemical oxidant, sodium hypochlorite, as a cost-effective agent for controlling zebra mussels at water treatment plant intakes. Toledo has used the sodium hypochlorite and reports the chemical has cleared colonies of zebra mussels that had attached to the intake of its water treatment plant

  11. Zebra Mussels Pose a Threat to Virginia's Waters

    OpenAIRE

    Helfrich, Louis A. (Louis Anthony), 1942-; Weigmann, Diana L.; Speenburgh, Renee M.; Neves, Richard J.; Kitchel, Lisie; Bruenderman, Sue A., 1962-

    2005-01-01

    Provides an brief introduction to the invasion of the zebra mussel into American waters, explains the economic consequences they pose, and discusses if Virginia will inherit the problem, what the public can do to help, the general lifecycle of the zebra mussel and if they can be controlled, and who is working on the zebra mussel problem.

  12. Summary of Ontario Hydro's 1990-91 zebra mussel research program

    International Nuclear Information System (INIS)

    Claudi, R.; Wiancko, P.M.

    1992-01-01

    Ontario Hydro is the principal supplier of electricity to the Province of Ontario. It serves 3.6 million customers, with an inservice capacity of 28,200 MW. Ontario Hydro has seven fossil, five nuclear, and four hydraulic stations in the Great Lakes Basin and surrounding watershed. In addition, there are another 60 inland hydraulic stations and numerous dams. As the largest single user of raw water from the Great Lakes Basin, Ontario Hydro recognized the need to control zebra mussels early in 1989. At that time, very little was known in North America about the zebra mussel life cycle and potential impact. European utilities were consulted, but as we now know, zebra mussels are not perceived to be a problem in Europe at this time. To satisfy the immediate need for control, chlorination was identified as the most effective interim measure to prevent the fouling of systems which draw water from the aquatic environment. Due to the current regulatory environment, this solution is considered short term and Ontario Hydro was compelled to initiate a comprehensive research effort aimed at providing alternative methods of control. Most of the research effort during 1990, was methods of control. Most of the research effort during 1990, was directed towards this goal. Many alternative control measures, both chemical and nonchemical were considered. Also considered were the potential effects of the control measures and zebra mussels on station operations. A multidisciplinary team involving aquatic biologists, chemists, corrosion specialists, and civil and mechanical engineers from the various departments of Ontario Hydro was asked to address the problem. Some of the research also involved collaborative studies with universities, US utilities, American Water Works Association, and Canadian industries. Following is a summary of the research effort in 1990, and a preview of the research underway in 1991

  13. Forecasting the expansion of zebra mussels in the United States.

    Science.gov (United States)

    Bossenbroek, Jonathan M; Johnson, Ladd E; Peters, Brett; Lodge, David M

    2007-06-01

    Because zebra mussels spread rapidly throughout the eastern United States in the late 1980s and early 1990s, their spread to the western United States has been expected. Overland dispersal into inland lakes and reservoirs, however, has occurred at a much slower rate than earlier spread via connected, navigable waterways. We forecasted the potential western spread of zebra mussels by predicting the overland movement of recreational boaters with a production-constrained gravity model. We also predicted the potential abundance of zebra mussels in two western reservoirs by comparing their water chemistry characteristics with those of water bodies with known abundances of zebra mussels. Most boats coming from waters infested with zebra mussels were taken to areas that already had zebra mussels, but a small proportion of such boats did travel west of the 100th meridian. If zebra mussels do establish in western U.S. water bodies, we predict that population densities could achieve similar levels to those in the Midwestern United States, where zebra mussels have caused considerable economic and ecological impacts. Our analyses suggest that the dispersal of zebra mussels to the western United States is an event of low probability but potentially high impact on native biodiversity and human infrastructure. Combining these results with economic analyses could help determine appropriate investment levels in prevention and control strategies.

  14. Evaluation of several chemical disinfectants for removing zebra mussels from unionid mussels

    Science.gov (United States)

    Waller, D.L.; Fisher, S.W.

    1998-01-01

    We evaluated the safety and effectiveness of chemical treatments for killing veliger and juvenile stages of the zebra mussel Dreissena polymorpha attached to unionid mussels. Static toxicity tests were conducted on eight unionid mussel species with common aquaculture chemicals (benzalkonium chloride, formalin, hydrogen peroxide, calcium chloride, potassium chloride, and sodium chloride). The concentration and duration of each chemical treatment tested had previously been found to kill zebra mussel veligers and juveniles. Several species (e.g., Elliptio dilatata, Lampsilis cardium, and Lasmigona complanata) incurred less than 10% mortality in chloride salt treatments, while in other species (e.g., Obliquaria reflexa and Leptodea fragilis) mortality varied greatly among treatment regimes. Treatments with benzalkonium chloride, formalin, and hydrogen peroxide were less than 90% effective on juvenile stages of zebra mussels and, therefore, were ruled out after preliminary trials. Limited application of specific chemical treatments may be feasible for more tolerant species; however, effective disinfection of unionid shells will require the use of chemical treatment followed by a quarantine period to completely remove zebra mussel larvae and juveniles.

  15. Zebra mussels invade Lake Erie muds

    Science.gov (United States)

    Berkman, Paul Arthur; Haltuch, Melissa A.; Tichich, Emily; Garton, David W.; Kennedy, Gregory W.; Gannon, John E.; Mackey, Scudder D.; Fuller, Jonathan A.; Liebenthal, Dale L.

    1998-01-01

    Zebra mussels (Dreissena polymorpha) originated in western Russia but have now become widespread in Europe and North America. They are widely known for their conspicuous invasion of rocks and other hard substrates in North American and European watersheds. We have found beds of zebra mussels directly colonizing sand and mud sediments each year across hundreds of square kilometres of North America's Lake Erie. This transformation of sedimentary habitats into mussel beds represents an unforeseen change in the invasive capacity of this species.

  16. USGS Zebra Mussel Monitoring Program for north Texas

    Science.gov (United States)

    Churchill, Christopher J.; Baldys, Stanley

    2012-01-01

    The U.S. Geological Survey (USGS) Zebra Mussel Monitoring Program for north Texas provides early detection and monitoring of zebra mussels (Dreissena polymorpha) by using a holistic suite of detection methods. The program is designed to assess zebra mussel occurrence, distribution, and densities in north Texas waters by using four approaches: (1) SCUBA diving, (2) water-sample collection with plankton tow nets (followed by laboratory analyses), (3) artificial substrates, and (4) water-quality sampling. Data collected during this type of monitoring can assist rapid response efforts and can be used to quantify the economic and ecological effects of zebra mussels in the north Texas area. Monitoring under this program began in April 2010. The presence of large zebra mussel populations often causes undesirable economic and ecological effects, including damage to water-processing infrastructure and hydroelectric powerplants (with an estimated 10-year cost of $3.1 billion), displacement of native mussels, increases in concentrations of certain species of cyanobacteria, and increases in concentrations of geosmin (an organic compound that results in taste and odor issues in water). Since no large-scale, environmentally safe eradication method has been developed for zebra mussels, it is difficult to remove established populations. Broad physicochemical adaptability, prolific reproductive capacity, and rapid dispersal methods have enabled zebra mussels, within a period of about 20 years, to establish populations under differing environmental conditions across much of the eastern part of the United States. In Texas, the presence of zebra mussels was first confirmed in April 2009 in Lake Texoma in the Red River Basin along the Texas-Oklahoma border. They were most likely introduced into Lake Texoma through overland transport from an infested water body. Since then, the presence of zebra mussels has been reported in both the Red River and Washita River arms of Lake Texoma, in

  17. Copper and copper-nickel alloys as zebra mussel antifoulants

    Energy Technology Data Exchange (ETDEWEB)

    Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K. [Univ. of Toronto, Ontario (Canada)

    1996-04-01

    Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

  18. EPRI's zebra mussel monitoring and control guidelines

    International Nuclear Information System (INIS)

    Mussalli, Y.G.; Armor, A.; Edwards, R.; Mattice, J.; Miller, M.; Nott, B.; Tsou, J.L.

    1992-01-01

    The Electric Power Research Institute (EPRI) Zebra Mussel Monitoring and Control Guidelines is a comprehensive compilation of US and European practices. The zebra mussel has infested all the Great Lakes and is positioned to spread to the adjoining river basins. The impact of the zebra mussel on power plants is as a biofouler clogging water systems and heat exchangers. The EPRI guidelines discuss the distribution of the zebra mussel in the US, identification of the zebra mussel, potential threats to power plants, and methods to initiate the monitoring and control program. Both preventive and corrective measures are presented. Preventive measures include various monitoring methods to initiate control techniques. The control techniques include both chemical and nonchemical together with combining techniques. Corrective methods include operational considerations, chemical cleaning, and mechanical/physical cleaning. It may also be possible to incorporate design changes, such as open to closed-loop backfit, backflushing, or pretreatment for closed systems. Table 1 shows a matrix of the monitoring methods. Table 2 presents a control matrix related to nuclear, fossil, and hydro raw water systems. Table 3 is a summary of the applicability of treatments to the various raw water systems. Appendixes are included that contain specifications to aid utilities in implementing several of the control technologies

  19. Quagga and zebra mussels: biology, impacts, and control

    Science.gov (United States)

    Nalepa, Thomas F.; Schloesser, Don W.; Nalepa, Thomas F.; Schloesser, Don W.

    2013-01-01

    Quagga and Zebra Mussels: Biology, Impacts, and Control, Second Edition provides a broad view of the zebra/quagga mussel issue, offering a historic perspective and up-to-date information on mussel research. Comprising 48 chapters, this second edition includes reviews of mussel morphology, physiology, and behavior. It details mussel distribution and spread in Europe and across North America, and examines policy and regulatory responses, management strategies, and mitigation efforts. In addition, this book provides extensive coverage of the impact of invasive mussel species on freshwater ecosystems, including effects on water clarity, phytoplankton, water quality, food web changes, and consequences to other aquatic fauna. It also reviews and offers new insights on how zebra and quagga mussels respond and adapt to varying environmental conditions. This new edition includes seven video clips that complement chapter text and, through visual documentation, provide a greater understanding of mussel behavior and distribution.

  20. Zebra mussel adhesion: structure of the byssal adhesive apparatus in the freshwater mussel, Dreissena polymorpha.

    Science.gov (United States)

    Farsad, Nikrooz; Sone, Eli D

    2012-03-01

    The freshwater zebra mussel (Dreissena polymorpha) owes a large part of its success as an invasive species to its ability to attach to a wide variety of substrates. As in marine mussels, this attachment is achieved by a proteinaceous byssus, a series of threads joined at a stem that connect the mussel to adhesive plaques secreted onto the substrate. Although the zebra mussel byssus is superficially similar to marine mussels, significant structural and compositional differences suggest that further investigation of the adhesion mechanisms in this freshwater species is warranted. Here we present an ultrastructural examination of the zebra mussel byssus, with emphasis on interfaces that are critical to its adhesive function. By examining the attached plaques, we show that adhesion is mediated by a uniform electron dense layer on the underside of the plaque. This layer is only 10-20 nm thick and makes direct and continuous contact with the substrate. The plaque itself is fibrous, and curiously can exhibit either a dense or porous morphology. In zebra mussels, a graded interface between the animal and the substrate mussels is achieved by interdigitation of uniform threads with the stem, in contrast to marine mussels, where the threads themselves are non-uniform. Our observations of several novel aspects of zebra mussel byssal ultrastructure may have important implications not only for preventing biofouling by the zebra mussel, but for the development of new bioadhesives as well. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Zebra mussel filtration and its potential uses in industrial water treatment.

    Science.gov (United States)

    Elliott, Paul; Aldridge, David C; Moggridge, Geoff D

    2008-03-01

    The zebra mussel (Dreissena polymorpha) is a notorious freshwater biofouling pest, and populations of the species can alter aquatic environments through their substantial filtration capabilities. Despite the ecological importance of zebra mussel filtration, many predictions of their large-scale effects on ecosystems rely on extrapolations from filtration rates obtained in static laboratory experiments, not accounting for natural mussel densities, boundary layer effects, flow rates or elevated algal concentrations. This study used large-scale industrial flume trials to investigate the influence of these factors on zebra mussel filtration and proposes some novel industrial applications of these findings. The flume trials revealed some of the highest zebra mussel clearance rates found to date, up to 574+/-20mlh(-1)g(-1) of wet tissue mass. Under low algal concentrations, chlorophyll a removal by zebra mussels was not proportional to mussel density, indicating that field rates of zebra mussel grazing may be much lower than previous studies have predicted. Increasing ambient velocities up to 100mls(-1) ( approximately 4cms(-1)) led to increased clearance rates by zebra mussels, possibly due to the replenishment of locally depleted resources, but higher velocities of 300mls(-1) (12cms(-1)) did not lead to further significant increases in clearance rate. When additional algal cultures were dosed into the flumes, chlorophyll a removal increased approximately logarithmically with zebra mussel density and there were no differences in the clearance of three different species of alga: Ankyra judayi, Pandorina morum and Cyclotella meneghinia. Some novel industrial uses of these zebra mussel filtration studies are proposed, such as: (1) helping to inform models that predict the large-scale grazing effects of the mussels, (2) allowing estimates of zebra mussel densities in industrial pipelines, and (3) constructing large-scale biofilters for use in water clarification.

  2. The zebra mussel

    International Nuclear Information System (INIS)

    Bertran, A.; Esparza, J.L.; Munte, L.

    2010-01-01

    The aim of this article is, on the one hand, to provide information about the zebra mussel, its behavior, its effect on the ecosystem and the problems it poses for industry (especially in the CNA cooling systems) and, on the other hand, to review the strategies and technologies needed to control de mussel and to present the solution adopted by the power plant to combat the plague. (Author).

  3. Review of techniques to prevent introduction of zebra mussels (Dreissena polymorpha) during native mussel (Unionoidea) conservation activities

    Science.gov (United States)

    Cope, W.G.; Newton, T.J.; Gatenby, C.M.

    2003-01-01

    Because of the declines in diversity and abundance of native freshwater mussels (superfamily Unionoidea), and the potential decimation of populations of native mussels resulting from the rapid spread of the exotic zebra mussel Dreissena polymorpha, management options to eliminate or reduce the threat of the zebra mussel are needed. Relocating native mussels to refugia (artificial and natural) has been proposed to mitigate the threat of zebra mussels to native species. Relocation of native mussels to refugia such as fish hatchery facilities or natural habitats within their historic range. Which are unlikely to be infested by zebra mussels, necessitates that protocols be developed to prevent the inadvertent introduction of zebra mussels. Several recent studies have developed Such protocols, and have assessed their effectiveness on the health and survival of native mussels during subsequent relocation to various refugia. The purpose of this project is to synthesize and evaluate the current protocols and to develop a set of procedures that resource managers and researchers should consider before conducting conservation activities in zebra mussel infested waters. We found that the existing protocols have many common points of concern, such as facility modification and suitability, zebra mussel risk assessment and management procedures, and health and disease management procedures. These conservation protocols may have broad applicability to other situations and locations. A summary and evaluation of the information in these main areas, along with recommended guidelines, are presented in this article.

  4. Control of zebra mussels with ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.P.

    1998-07-01

    This paper presents the results of research on the effects of low and medium pressure ultraviolet (UV) radiation on zebra mussel mortality carried out between 1992 and 1995. An initial 1992 study, carried out by Aquatic Sciences (ASI), showed that flow-through UV systems have the ability to kill zebra mussels and prevent them from attaching to downstream surfaces. However, this work did not include expanded testing to determine the limitations of UV radiation at higher flow rates or to further define effective working parameters. The 1994 study was carried out at the Lennox Thermal Generating Station (TGS) of Ontario Hydro in Kingston, Ontario. This study involved the testing of two open channel UV systems (medium and low pressure) in an effort to determine flow rates and volumes for which UV disinfection would be effective and practical for the prevention of zebra mussel infestation. It was recommended that medium pressure (MP) and low pressure (LP) UV systems be tested for their ability to control downstream settlement of zebra mussels, in flow-through trials.

  5. Mitigation of unionid mortality caused by zebra mussel infestation: cleaning of unionids

    Science.gov (United States)

    Schloesser, Don W.

    1996-01-01

    Exotic zebra mussels Dreissena polymorpha have infested and caused mortality of native unionids in the Great Lakes since 1986; no other such parasitism of native unionids occurs in North America. Survival of unionids threatened by zebra mussel infestation was tested by suspending uncleaned and cleaned unionids in nearshore waters of western Lake Erie. Survival was determined, and newly settled zebra mussels were removed from clean unionids at eight intervals that ranged from 21 d to 77 d between 5 July 1990 and 3 July 1991. After 1 year, survival rates of uncleaned and cleaned unionids were 0% and 42%, respectively. Of the 10 species examined, only indivduals from 3 species (Amblema plicata plicata, Fusconaia flava, and Quadrula quadrula) survived 1 year. These species have relatively thick shells, which may have contributed to their survival. Removal of newly settled zebra mussels may be important to unionid survival because 98% of the zebra mussels removed after the initial cleaning were small mussels (zebra mussels cause mortality of unionids, but the removal of zebra mussels from unionids is the only method known that successfully reduces unionid mortality in waters colonized by zebra mussels.

  6. A dominance shift from the zebra mussel to the invasive quagga mussel may alter the trophic transfer of metals

    International Nuclear Information System (INIS)

    Matthews, Jonathan; Schipper, Aafke M.; Hendriks, A. Jan; Yen Le, T.T.; Vaate, Abraham bij de; Velde, Gerard van der; Leuven, Rob S.E.W.

    2015-01-01

    Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra mussels (Dreissena polymorpha) to quagga mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga mussels were significantly lower than in zebra mussels overall. In lakes, quagga mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra mussels. In the river water type quagga mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga mussels may reduce metal exposure of predator species. - Highlights: • Invading quagga mussels often displace existing zebra mussels. • Interspecies difference in metal concentration may alter exposure of predators. • Zebra and quagga mussel soft tissue were analysed for metal concentrations. • Generally, quagga mussels contained lower concentrations of metals. • A dominance shift to quagga mussels may reduce metal exposure of predators. - A shift in dominance from zebra mussels to invading quagga mussels may reduce the transfer of metals to predator species

  7. IMPACT OF WATER PH ON ZEBRA MUSSEL MORTALITY

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2002-01-01

    The experiments conducted this past quarter have suggested that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels throughout the entire range of pH values tested (7.2 to 8.6). Highest mortality was achieved at pH values characteristic of preferred zebra mussel waterbodies, i.e., hard waters with a range of 7.8 to 8.6. In all water types tested, however, ranging from very soft to very hard, considerable mussel kill was achieved (83 to 99% mean mortality), suggesting that regardless of the pH or hardness of the treated water, significant mussel kill can be achieved upon treatment with P. fluorescens strain CL0145A. These results further support the concept that this bacterium has significant potential for use as a zebra mussel control agent in power plant pipes receiving waters with a wide range of physical and chemical characteristics

  8. IMPACT OF WATER PH ON ZEBRA MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2002-10-15

    The experiments conducted this past quarter have suggested that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels throughout the entire range of pH values tested (7.2 to 8.6). Highest mortality was achieved at pH values characteristic of preferred zebra mussel waterbodies, i.e., hard waters with a range of 7.8 to 8.6. In all water types tested, however, ranging from very soft to very hard, considerable mussel kill was achieved (83 to 99% mean mortality), suggesting that regardless of the pH or hardness of the treated water, significant mussel kill can be achieved upon treatment with P. fluorescens strain CL0145A. These results further support the concept that this bacterium has significant potential for use as a zebra mussel control agent in power plant pipes receiving waters with a wide range of physical and chemical characteristics.

  9. Prevention of zebra mussel infestation and dispersal during aquaculture operations

    Science.gov (United States)

    Waller, D.L.; Fisher, S.W.; Dabrowska, H.

    1996-01-01

    The zebra mussel Dreissena polymorpha, an exotic invasive species, poses a major threat to North American fish management programs and the aquaculture industry. Fish hatcheries may become infected with zebra mussels from a variety of sources, including the water supply, fish shipments, boats, and equipment. The hatcheries could then serve as agents for the overland dispersal of zebra mussels into stocked waters and to other fish hatcheries. We evaluated the effectiveness and safety of aquaculture chemicals for use in controlling zebra mussels in fish hatcheries and preventing dispersal of veligers during fish transport. Chemicals were evaluated for use in fish transport and as disinfectants for ponds and equipment. Standardized static toxicity tests were conducted with representative species of warmwater, coolwater, and coldwater fishes and with larval (3-d-old veligers), early juvenile (settling larvae), and adult zebra mussels. Chemical concentrations and exposure durations were based on recommended treatment levels for fish, eggs, and ponds. Recommended treatment levels were also exceeded, if necessary, to establish lethal levels for zebra mussels of different developmental stages. Our results indicate that some chemicals currently in use in hatcheries may be effective for controlling zebra mussels in various operations. Chloride salts were the safest and most effective therapeutants tested for use in fish transport. The toxicity of chloride salts to fish varied among species and with temperature; only one treatment regime (sodium chloride at 10,000 mg/L) was safe to all fish species that we tested, but it was only effective on veliger and settler stages of the zebra mussel. Effective disinfectants were benzalkonium chloride for use on equipment and rotenone for use in ponds after fish are harvested. The regulatory status of the identified chemicals is discussed as well as several nonchemical control alternatives.

  10. Predation on exotic zebra mussels by native fishes: Effects on predator and prey

    Science.gov (United States)

    Magoulick, D.D.; Lewis, L.C.

    2002-01-01

    1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra mussel densities. We tested these hypotheses by observing prey use of fishes, determining energy content of primary prey species of fishes, and conducting predator exclusion experiments in Lake Dardanelle, Arkansas. 2. Zebra mussels were the primary prey eaten by 52.9% of blue catfish, Ictalurus furcatus; 48.2% of freshwater drum, Aplodinotus grunniens; and 100% of adult redear sunfish, Lepomis microlophus. Blue catfish showed distinct seasonal prey shifts, feeding on zebra mussels in summer and shad, Dorosoma spp., during winter. Energy content (joules g-1) of blue catfish prey (threadfin shad, Dorosoma petenense; gizzard shad, D. cepedianum; zebra mussels; and asiatic clams, Corbicula fluminea) showed a significant species by season interaction, but shad were always significantly greater in energy content than bivalves examined as either ash-free dry mass or whole organism dry mass. Fish predators significantly reduced densities of large zebra mussels (>5 mm length) colonising clay tiles in the summers of 1997 and 1998, but predation effects on small zebra mussels (???5 mm length) were less clear. 3. Freshwater drum and redear sunfish process bivalve prey by crushing shells and obtain low amounts of higher-energy food (only the flesh), whereas blue catfish lack a shell-crushing apparatus and ingest large amounts of low-energy food per unit time (bivalves with their shells). Blue catfish appeared to select the abundant zebra mussel over the more energetically rich shad during summer, then shifted to shad during winter when shad experienced temperature-dependent stress and mortality. Native fish predators can suppress adult zebra

  11. Scope of problem assessed at IVO. The zebra mussel`s campaign of world conquest

    Energy Technology Data Exchange (ETDEWEB)

    Silvonen, J; Oesch, P [ed.

    1998-07-01

    The migrating shell - or `zebra mussel` as it is called on account of its black and white stripes - was originally a fresh-water mussel, but has since also adapted to brackish waters. As a result of human activity the species has spread quickly and widely from its native habitat. Operators of power plants and water treatment plants in particular have not been very happy about this. During its larval stage the zebra mussel can enter the cooling water systems; fasten itself to the pipes and - in the worst case - clog the system. The Environmental Protection Division of IVO has been assessing the spread of the zebra mussel and the resulting problems with the aid of reference literature and the assistance of Finnish researchers

  12. Co-existence of zebra mussels and freshwater unionids: Population dynamics of Leptodea fragilis in a coastal wetland infested with zebra mussels

    Science.gov (United States)

    Nichols, S. Jerrine; Amberg, Jon

    1999-01-01

    In 1996, thousands of live Leptodea fragilis were collected from a marsh located in the western basin of Lake Erie that was infested with zebra mussels (Dreissena polymorpha). Despite the presence of zebra mussels at this site for a number of years, this L. fragilis population showed no signs of competition-induced changes in population dynamics. Biofouling was limited: fewer than 1% of the L. fragilis showed evidence of recent or past zebra mussel colonization. Successful recruitment occurred yearly, with multiple year classes collected that ranged in age from 1 to 12 years. However, age and shell length were not well correlated. Seventy-one percent of the individuals collected were 51-80 mm long, but ranged in age from 2 to 4.5 years. Three different patterns of growth or shell deposition were found. Some individuals grew rapidly, reaching 105 mm in 3.5 years, while others grew only 4.5 mm over the same time period. A few grew poorly during some years but very rapidly in others. Individuals with a shell length of 41 mm or more were sexually mature and females were more common than males. The strong recruitment and steady growth of this population showed no change between the years before and after the zebra mussel invasion, indicating that this marsh is functioning as a natural refugium from potential problems caused by zebra mussels.

  13. Occurrence of zebra mussels in near-shore areas of western Lake Erie

    Science.gov (United States)

    Custer, Christine M.; Custer, T.W.

    1997-01-01

    Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels, (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( = 10.7 i?? 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( = 4.4 i?? 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.

  14. The Effect of Zebra Mussels on Algal Community Structure in an Impounded River System

    Science.gov (United States)

    Trumble, A. F.; Luttenton, M.

    2005-05-01

    The zebra mussel, Dreissena polymorpha, invaded the Great Lakes Region in the mid 1980's, and subsequently colonized inland lakes and coastal river systems through secondary invasions. The Muskegon River below Croton Dam was colonized by zebra mussels in 2000 following their introduction into Croton impoundment in the late 1990's. No zebra mussels were found below Croton Dam in 1999 but had increased to 25,000 m-2 by 2001. We examined the affect of zebra mussels on epilithic periphyton communities by comparing plots that were and were not colonized by zebra mussels. Chlorophyll a increased in both treatments over time but was significantly higher in control plots than in zebra mussel plots. The concentration of chlorophyll a in the control plots increased from 14 µgcm-2 to 26 µgcm-2 and the concentration in the zebra mussel plots started at 12 µgcm-2, peaked at 19 µgcm-2, and then decreased to 15 µgcm-2 over a 6 week period. In a related experiment using artificial streams, chlorophyll a increased with increasing zebra mussel density, but differences were not significant. The different trends observed between the two experiments may be explained in part by arthropod invertebrates associated with zebra mussel populations.

  15. Preference of redear sunfish on zebra mussels and rams-horn snails

    Science.gov (United States)

    French, John R. P.; Morgan, Michael N.

    1995-01-01

    We tested prey preferences of adult (200- to 222-mm long) redear sunfish (Lepomis microlophus) on two size classes of zebra mussels (Dreissena polymorpha) and two-ridge rams-horns (Helisoma anceps) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

  16. A dominance shift from the zebra mussel to the invasive quagga mussel may alter the trophic transfer of metals.

    Science.gov (United States)

    Matthews, Jonathan; Schipper, Aafke M; Hendriks, A Jan; Yen Le, T T; Bij de Vaate, Abraham; van der Velde, Gerard; Leuven, Rob S E W

    2015-08-01

    Bioinvasions are a major cause of biodiversity and ecosystem changes. The rapid range expansion of the invasive quagga mussel (Dreissena rostriformis bugensis) causing a dominance shift from zebra mussels (Dreissena polymorpha) to quagga mussels, may alter the risk of secondary poisoning to predators. Mussel samples were collected from various water bodies in the Netherlands, divided into size classes, and analysed for metal concentrations. Concentrations of nickel and copper in quagga mussels were significantly lower than in zebra mussels overall. In lakes, quagga mussels contained significantly higher concentrations of aluminium, iron and lead yet significantly lower concentrations of zinc66, cadmium111, copper, nickel, cobalt and molybdenum than zebra mussels. In the river water type quagga mussel soft tissues contained significantly lower concentrations of zinc66. Our results suggest that a dominance shift from zebra to quagga mussels may reduce metal exposure of predator species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. IMPACT OF WATER TEMPERATURE ON ZEBRA MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2002-08-07

    These tests conducted this past quarter have indicated that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels at water temperatures ranging from 7 to 23 C. Percent kill will likely be somewhat lower at very low temperatures, e.g., 7 C, but even at such low temperatures high mussel kill can still be achieved (>70% kill). This is significant because the development of a zebra mussel control method that is efficacious in such a wide range of temperatures broadens its usefulness as a potential commercial product.

  18. Predation of the zebra mussel (Dreissena polymorpha) by freshwater drum in western Lake Erie

    Science.gov (United States)

    French, John R. P.; Bur, Michael T.; Nalepa, Thomas F.; Schloesser, Donald W.

    1992-01-01

    Environmental and economic problems associated with the colonization of zebra mussels (Dreissena polymorpha) in western Lake Erie created a need to investigate control mechanisms. Predation by fishes is one potential means of control, but predation on zebra mussels by native fishes in Lake Erie is unknown. The freshwater drum (Aplodinotus grunniens) is the most likely fish predator since it is the only fish with pharyngeal teeth capable of crushing mollusk shells. In 1990, freshwater drum were collected in western Lake Erie from 9 sites near rocky reefs and 13 sites with silt or sand bottoms, and gut contents were examined. Predation on zebra mussels increased as drum size increased. Small drum (200-249 mm in length) fed mainly on dipterans, amphipods, and small fish; small zebra mussels (375 mm in length) fed almost exclusively on zebra mussels (seasons and locations combined). The smallest drum capable of crushing zebra mussel shells was 265 mm. Since freshwater drum over 375 mm feed heavily on zebra mussels, they may become a possible biological control mechanism for mussels in portions of North America.

  19. Evaluation of zebra mussels (Dreissena polymorpha) as biomonitors of mercury contamination in aquatic ecosystems.

    Science.gov (United States)

    Blackwell, Bradley D; Driscoll, Charles T; Spada, Michael E; Todorova, Svetoslava G; Montesdeoca, Mario R

    2013-03-01

    Zebra mussels have invaded many lakes in the United States and could be a useful tool for monitoring responses of aquatic biota to changes in mercury loading. The goal of the present study was to evaluate zebra mussels for use as a biomonitor of mercury contamination by comparing zebra mussel mercury concentrations between a lake with only indirect atmospheric mercury contamination (Otisco Lake, NY, USA) and a lake that was directly contaminated by mercury discharges (Onondaga Lake, NY, USA). Zebra mussels were sampled in both the spring and fall of 2004 and 2005. Total mercury (THg) concentrations in zebra mussels were approximately seven times greater in Onondaga Lake than in Otisco Lake, and water column mercury concentrations differed by an order of magnitude between the two lakes. Seasonal differences resulted in significantly higher zebra mussel THg concentrations during the fall for both lakes. There was also significant variation among different sampling sites in Onondaga Lake. Mussel methylmercury concentrations averaged 53% of THg concentrations but were highly variable. Strong relationships between water column THg and zebra mussel THg suggest that zebra mussels are a good indicator of aquatic mercury concentrations and could be used as an effective biomonitor of mercury contamination in aquatic ecosystems. Copyright © 2013 SETAC.

  20. Invasion of the Zebra Mussels: A Mock Trial Activity

    Science.gov (United States)

    Beck, Judy A.; Czerniak, Charlene M.

    2005-01-01

    In this activity, students learn about the important topic of invasive species, specifically Zebra Mussels. Students role-play different characters in a real-life situation: the trial of the Zebra Mussel for unlawful disruption of the Great Lakes ecosystem. Students will also learn about jurisprudential inquiry by examining the trial process. This…

  1. Interactions among zebra mussel shells, invertebrate prey, and Eurasian ruffe or yellow perch

    Science.gov (United States)

    Kolar, C.S.; Fullerton, A.H.; Martin, K.M.; Lamberti, G.A.

    2002-01-01

    The exotic zebra mussel, Dreissena polymorpha, is established in all of the Laurentian Great Lakes and may affect benthivorous fishes by increasing the complexity of benthic substrates and changing energy flow patterns within the food web. Native yellow perch, Perca flavescens, and the nonindigenous Eurasian ruffe, Gymnocephalus cernuus, are benthivores that may compete for limited food resources. As ruffe spread to areas with more dense zebra mussel populations, the zone of interaction among zebra mussels, yellow perch, and ruffe will increase and intensify. In the laboratory, the effect of zebra mussel shells on the ability of these fishes to forage on amphipods (Gammarus pseudolimnaeus) and chironomids (Chironomus plumosus) was examined in light and darkness. In 12 h, ruffe consumed more amphipods than did similar-sized yellow perch, particularly in darkness on bare cobble, and in light within zebra mussels. Amphipods decreased activity more in the presence of ruffe than yellow perch. More amphipods were found in zebra mussel shells than in bare cobble, whether or not fish were present. In darkness, when ruffe consumed more amphipods on bare cobble, amphipods became more associated with zebra mussel shells. Although ruffe consumed more amphipods than yellow perch, perch consumed more chironomids than ruffe on bare cobble. The presence of zebra mussel shells altered the relative consumption of invertebrates in some substrate-light combinations. Experiments such as these help to improve understanding of the direct and indirect effects of predation between and among native and nonindigenous species that may exert structuring forces on the nearshore communities of the Great Lakes currently or in the future.

  2. Biogeochemical alteration of the benthic environment by the zebra mussel Dreissena polymorpha (Pallas

    Directory of Open Access Journals (Sweden)

    Alina Krevš

    2010-12-01

    Full Text Available The aim of this study was to verify whether the biogeochemicalfeatures (e.g. concentration of nutrients, oxygen consumption,mineralization rate, Eh of sediments changed by the zebra musselor its shell deposits differ from those in the ambient soft bottom,and how these differences are related to the structure of benthicmacroinvertebrates. In 2006 three sampling sessions were carriedout in the Curonian Lagoon, SE Baltic Sea, at three pre-definedsites, corresponding to different bottom types: zebra musselbed, zebra mussel shell deposits and bare soft sediments. Similarityanalysis of biogeochemical parameters indicated that bottom sedimentscovered with zebra mussel shell deposits were rather distinctfrom the other bottom types because of the lowest total organicmatter mineralization rate and highest organic carbon, totalphosphorus and total nitrogen content. The parameters measuredin the zebra mussel bed did not deviate conspicuously from thevalues observed in bare bottoms, except for the higher rate ofoxygen consumption in the upper sediment layer. Unsuitable anoxicconditions on the one hand and the "attractive" shelters providedby zebra mussels on the other hand may promote the epifaunallife style in the habitats formed by dense zebra mussel clumps.

  3. Zebra mussel control using acoustic energy

    International Nuclear Information System (INIS)

    Tiller, G.W.; Gaucher, T.A.; Menezes, J.K.; Dolat, S.W.

    1992-01-01

    A practical and economical device or method that reduces zebra mussel colonization without detrimental side effects is highly desirable. An ideal method is one that could be installed near, on, or in existing raw water intakes and conduits. It must have a known effect that is limited to a defined area, should have maximum effects on a targeted species, and preferably have a low life cycle cost than the current alternative methods of control and maintenance. Underwater sound could be such a desirable solution, if found to be an effective control measure for zebra mussels. Although sound most often applies specifically to acoustic energy that is audible to humans, 20 Hertz (Hz) to 20 kiloHertz (kHz), in this report we will use the terms sound and acoustic to include acoustic energy between 100 Hz and 100 MegaHertz (MHz). This research on zebra mussel biofouling is designed to effect the early developmental stages in the life cycle of Dreissena polymorpha (Pallas). Vulnerable stages in the development of D. polymorpha that might yield to site-specific acoustic deterrence measures include the free-swimming larval veliger stage, the postveliger pre-attachment demersal stage, and the immediate post-attachment stage. The proposed applications include surface treatment to prevent, reduce or eliminate colonization on underwater structures, and the stream treatment to reduce or eliminate (destroy) mussel larvae entrained in a moving volume of water

  4. How well can fishes prey on zebra mussels in eastern North America?

    Science.gov (United States)

    French, John R. P.

    1993-01-01

    Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum (Aplodinotus grunniens) and two centrarchids, redear sunfish (Lepomis microlophus) and pumpkinseed (L. gibbosus), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses (Moxostoma hubbsi and M. carinatum), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp (Cyprinus carpio), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach (Rutilus rutilus) and the black carp (Mylopharyngodon piceus) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

  5. Economic impacts of zebra mussels on drinking water treatment and electric power generation facilities.

    Science.gov (United States)

    Connelly, Nancy A; O'Neill, Charles R; Knuth, Barbara A; Brown, Tommy L

    2007-07-01

    Invasions of nonnative species such as zebra mussels can have both ecological and economic consequences. The economic impacts of zebra mussels have not been examined in detail since the mid-1990s. The purpose of this study was to quantify the annual and cumulative economic impact of zebra mussels on surface water-dependent drinking water treatment and electric power generation facilities (where previous research indicated the greatest impacts). The study time frame was from the first full year after discovery in North America (Lake St. Clair, 1989) to the present (2004); the study area was throughout the mussels' North American range. A mail survey resulted in a response rate of 31% for electric power companies and 41% for drinking water treatment plants. Telephone interviews with a sample of nonrespondents assessed nonresponse bias; only one difference was found and adjusted for. Over one-third (37%) of surveyed facilities reported finding zebra mussels in the facility and almost half (45%) have initiated preventive measures to prevent zebra mussels from entering the facility operations. Almost all surveyed facilities (91%) with zebra mussels have used control or mitigation alternatives to remove or control zebra mussels. We estimated that 36% of surveyed facilities experienced an economic impact. Expanding the sample to the population of the study area, we estimated 267 million dollars (BCa 95% CI = 161 million dollars - 467 million dollars) in total economic costs for electric generation and water treatment facilities through late 2004, since 1989. Annual costs were greater (44,000 dollars/facility) during the early years of zebra mussel infestation than in recent years (30,000 dollars). As a result of this and other factors, early predictions of the ultimate costs of the zebra mussel invasion may have been excessive.

  6. Bioaccumulation of pathogenic bacteria and amoeba by zebra mussels and their presence in watercourses.

    Science.gov (United States)

    Mosteo, R; Goñi, P; Miguel, N; Abadías, J; Valero, P; Ormad, M P

    2016-01-01

    Dreissena polymorpha (the zebra mussel) has been invading freshwater bodies in Europe since the beginning of the nineteenth century. Filter-feeding organisms can accumulate and concentrate both chemical and biological contaminants in their tissues. Therefore, zebra mussels are recognized as indicators of freshwater quality. In this work, the capacity of the zebra mussel to accumulate human pathogenic bacteria and protozoa has been evaluated and the sanitary risk associated with their presence in surface water has also been assessed. The results show a good correlation between the pathogenic bacteria concentration in zebra mussels and in watercourses. Zebra mussels could therefore be used as an indicator of biological contamination. The bacteria (Escherichia coli, Enterococcus spp., Pseudomonas spp., and Salmonella spp.) and parasites (Cryptosporidium oocysts and free-living amoebae) detected in these mussels reflect a potential sanitary risk in water.

  7. Will the Displacement of Zebra Mussels by Quagga Mussels Increase Water Clarity in Shallow Lakes during Summer? Results from a Mesocosm Experiment

    OpenAIRE

    Mei, Xueying; Zhang, Xiufeng; Kassam, Sinan-Saleh; Rudstam, Lars G.

    2016-01-01

    Zebra mussels (Dreissena polymorpha) are known to increase water clarity and affect ecosystem processes in invaded lakes. During the last decade, the conspecific quagga mussels (D. rostriformis bugensis) have displaced zebra mussels in many ecosystems including shallow lakes such as Oneida Lake, New York. In this study, an eight-week mesocosm experiment was conducted to test the hypothesis that the displacement of zebra mussels by quagga mussels leads to further decreases in phytoplankton and...

  8. Uptake of dissolved organic carbon and trace elements by zebra mussels

    Science.gov (United States)

    Roditi, Hudson A.; Fisher, Nicholas S.; Sañudo-Wilhelmy, Sergio A.

    2000-09-01

    Zebra mussels (Dreissena polymorpha) are widespread and abundant in major freshwater ecosystems in North America, even though the phytoplankton food resources in some of these systems seem to be too low to sustain them. Because phytoplankton biomass is greatly depleted in ecosystems with large D. polymorpha populations and bacteria do not seem to be an important food source for this species, exploitation of alternative carbon sources may explain the unexpected success of D. polymorpha in such environments. Here we examine the possibility that absorption of dissolved organic carbon (DOC) from water could provide a nutritional supplement to zebra mussels. We find that mussels absorb 14C-labelled DOC produced by cultured diatoms with an efficiency of 0.23%; this indicates that DOC in natural waters could contribute up to 50% of the carbon demand of zebra mussels. We also find that zebra mussels absorb some dissolved metals that have been complexed by the DOM; although absorption of dissolved selenium was unaffected by DOC, absorption of dissolved cadmium, silver and mercury by the mussels increased 32-, 8.7- and 3.6-fold, respectively, in the presence of high-molecular-weight DOC.

  9. Efficacy of candidate chemicals for preventing attachment of zebra mussels (Dreissena polymorpha)

    Science.gov (United States)

    Cope, W.G.; Bartsch, M.R.; Marking, L.L.

    1997-01-01

    Forty-seven chemicals having potential for preventing the attachment of zebra mussels Dreissena polymorpha were identified and tested. For each chemical, 15 zebra mussels (5-8-mm shell length) in each of two replicates and six treatments were exposed for 48 h followed by a 48-h postexposure period in untreated water. Eleven of the chemicals inhibited the reattachment of zebra mussels after the 48-h exposure; eight had EC50 values ranging from 0.4 to 5.4 mg /L, and three had EC50 values ranging from 19.4 to 29.0 mg/L. Based on an analysis of chemical cost, solubility in water, anticipated treatment concentrations, and potential hazards to humans or the environment, three of the most promising chemicals, all antioxidants (butylated hydroxyanisole [BHA], tert-butylhydroquinone, and tannic acid) were tested on nontarget fish (bluegill, Lepomis macrochirus; channel catfish, Ictalurus punctatus; and rainbow trout, Oncorhynchus mykiss). These chemicals were not selectively toxic to zebra mussels; only the tests with bluegill and BHA and with channel catfish and tannic acid had 48-h LC50 values greater than the concentrations effective for preventing the reattachment of zebra mussels. Although the attachment of zebra mussels can be prevented with selected antioxidants, an alternative formulation should be investigated to minimize effects on nontarget organisms, such as fish.

  10. Food habits of diving ducks in the Great Lakes after the zebra mussel invasion

    Science.gov (United States)

    Custer, Christine M.; Custer, T.W.

    1996-01-01

    Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( = 10.7 i?? 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( = 4.4 i?? 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.

  11. Development of a molecular diagnostic system to discriminate Dreissena polymorpha (zebra mussel) and Dreissena bugensis (quagga mussel)

    Science.gov (United States)

    Hoy, M.S.; Kelly, K.; Rodriguez, R.J.

    2010-01-01

    A 3-primer PCR system was developed to discriminate invasive zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel. The system is based on: 1) universal primers that amplifies a region of the nuclear 28s rDNA gene from both species and 2) a species-specific primer complementary to either zebra or quagga mussel. The species-specific primers bind to sequences between the binding sites for the universal primers resulting in the amplification of two products from the target species and one product from the nontarget species. Therefore, nontarget products are positive amplification controls. The 3-primer system accurately discriminated zebra and quagga mussels from seven geographically distinct populations.

  12. Zebra Mussel Research Technical Notes. Impacts of Zebra Mussel Infestations on Water Quality. Section 1 - Environmental Testing

    National Research Council Canada - National Science Library

    Ashby, Steven

    1998-01-01

    ..., and sediment quality. The purpose of this technical note describes potential changes in water quality as a result of zebra mussel infestations in aquatic systems, based on a review of the literature...

  13. Mortality of zebra mussel, Dreissena polymorpha, veligers during downstream transport

    Science.gov (United States)

    Horvath, T.G.; Lamberti, G.A.

    1999-01-01

    1. Streams flowing from lakes which contain zebra mussels, Dreissena polymorpha, provide apparently suitable habitats for mussel colonization and downstream range expansion, yet most such streams contain few adult mussels. We postulated that mussel veligers experience high mortality during dispersal via downstream transport. They tested this hypothesis in Christiana Creek, a lake-outlet stream in south-western Michigan, U.S.A., in which adult mussel density declined exponentially with distance downstream. 2. A staining technique using neutral red was developed and tested to distinguish quickly live and dead veligers. Live and dead veligers were distinguishable after an exposure of fresh samples to 13.3 mg L-1 of neutral red for 3 h. 3. Neutral red was used to determine the proportion of live veligers in samples taken longitudinally along Christiana Creek. The proportion of live veligers (mean ?? SE) declined from 90 ?? 3% at the lake outlet to 40 ?? 8% 18 km downstream. 4. Veligers appear to be highly susceptible to damage by physical forces (e.g. shear), and therefore, mortality in turbulent streams could be an important mechanism limiting zebra mussel dispersal to downstream reaches. Predictions of zebra mussel spread and population growth should consider lake-stream linkages and high mortality in running waters.

  14. The zebra mussel; El mejillon cebra

    Energy Technology Data Exchange (ETDEWEB)

    Bertran, A.; Esparza, J.L.; Munte, L.

    2010-07-01

    The aim of this article is, on the one hand, to provide information about the zebra mussel, its behavior, its effect on the ecosystem and the problems it poses for industry (especially in the CNA cooling systems) and, on the other hand, to review the strategies and technologies needed to control de mussel and to present the solution adopted by the power plant to combat the plague. (Author).

  15. The effects of natural biofilms on the reattachment of young adult zebra mussels to artificial substrata.

    Science.gov (United States)

    Kavouras, Jerry H; Maki, James S

    2003-08-01

    This laboratory study examined the effects of natural biofilms on the reattachment of young adult zebra mussels, Dreissena polymorpha, in Petri dishes. Natural biofilms were developed in glass and polystyrene Petri dishes using water samples collected at various times of the year. Biofilms were developed over 1, 3, 8, and 14 d. Controls were clean glass and polystyrene Petri dishes. Zebra mussels collected from the field (Zebra mussels reattached to the dish surface or the shells of other mussels in the dish, or remained unattached. The data indicate that reattachment to clean glass was greater than to clean polystyrene (p Zebra mussels in control and filmed glass dishes reattached in higher percentages to the dish surface compared to the shells of other mussels (p mussel of reattachment between the dish surface and the shells of other mussels in most control polystyrene dishes (p > 0.05, ANOVA), whereas in filmed polystyrene the percentage of reattachment to the dish surface was greater than to the shells of other mussels (p zebra mussels.

  16. Will the Displacement of Zebra Mussels by Quagga Mussels Increase Water Clarity in Shallow Lakes during Summer? Results from a Mesocosm Experiment.

    Directory of Open Access Journals (Sweden)

    Xueying Mei

    Full Text Available Zebra mussels (Dreissena polymorpha are known to increase water clarity and affect ecosystem processes in invaded lakes. During the last decade, the conspecific quagga mussels (D. rostriformis bugensis have displaced zebra mussels in many ecosystems including shallow lakes such as Oneida Lake, New York. In this study, an eight-week mesocosm experiment was conducted to test the hypothesis that the displacement of zebra mussels by quagga mussels leads to further decreases in phytoplankton and increases in water clarity resulting in increases in benthic algae. We found that the presence of zebra mussels alone (ZM, quagga mussels alone (QM, or an equal number of both species (ZQ reduced total phosphorus (TP and phytoplankton Chl a. Total suspended solids (TSS was reduced in ZM and ZQ treatments. Light intensity at the sediment surface was higher in all three mussel treatments than in the no-mussel controls but there was no difference among the mussel treatments. There was no increase in benthic algae biomass in the mussel treatments compared with the no-mussel controls. Importantly, there was no significant difference in nutrient (TP, soluble reactive phosphorus and NO3- levels, TSS, phytoplankton Chl a, benthic algal Chl a, or light intensity on the sediment surface between ZM, QM and ZQ treatments. These results confirm the strong effect of both mussel species on water clarity and indicate that the displacement of zebra mussel by an equivalent biomass of quagga mussel is not likely to lead to further increases in water clarity, at least for the limnological conditions, including summer temperature, tested in this experiment.

  17. Will the Displacement of Zebra Mussels by Quagga Mussels Increase Water Clarity in Shallow Lakes during Summer? Results from a Mesocosm Experiment.

    Science.gov (United States)

    Mei, Xueying; Zhang, Xiufeng; Kassam, Sinan-Saleh; Rudstam, Lars G

    2016-01-01

    Zebra mussels (Dreissena polymorpha) are known to increase water clarity and affect ecosystem processes in invaded lakes. During the last decade, the conspecific quagga mussels (D. rostriformis bugensis) have displaced zebra mussels in many ecosystems including shallow lakes such as Oneida Lake, New York. In this study, an eight-week mesocosm experiment was conducted to test the hypothesis that the displacement of zebra mussels by quagga mussels leads to further decreases in phytoplankton and increases in water clarity resulting in increases in benthic algae. We found that the presence of zebra mussels alone (ZM), quagga mussels alone (QM), or an equal number of both species (ZQ) reduced total phosphorus (TP) and phytoplankton Chl a. Total suspended solids (TSS) was reduced in ZM and ZQ treatments. Light intensity at the sediment surface was higher in all three mussel treatments than in the no-mussel controls but there was no difference among the mussel treatments. There was no increase in benthic algae biomass in the mussel treatments compared with the no-mussel controls. Importantly, there was no significant difference in nutrient (TP, soluble reactive phosphorus and NO3-) levels, TSS, phytoplankton Chl a, benthic algal Chl a, or light intensity on the sediment surface between ZM, QM and ZQ treatments. These results confirm the strong effect of both mussel species on water clarity and indicate that the displacement of zebra mussel by an equivalent biomass of quagga mussel is not likely to lead to further increases in water clarity, at least for the limnological conditions, including summer temperature, tested in this experiment.

  18. Effects of the exotic zebra mussel (Dreissena polymorpha) on metal cycling in Lake Erie

    International Nuclear Information System (INIS)

    Klerks, P.L.; Fraleigh, P.C.; Lawniczak, J.E.

    1997-01-01

    This research demonstrated the impact of high densities of the zebra mussel (Dreissena polymorpha) on the cycling of copper, nickel, and zinc in a lake environment. Experiments with mussels on sedimentation traps in western Lake Erie and with mussels in flow-through tanks receiving Lake Erie water showed that zebra mussels remove metals from the water column, incorporate metals in their tissues, and deposit metals on the lake bottom. Removal of metals from the water column was estimated at 10-17%·day -1 of the amounts present. This material was largely deposited on the lake bottom; zebra mussels more than doubled the rate at which metals were being added to the lake bottom. Metal biodeposition rates were extremely high (e.g., 50 mg Zn·m -2 ·day -1 ) in high-turbidity areas with elevated metal levels. Two factors contributed to metal biodeposition by zebra mussels. First, their production of feces and pseudofeces increased the rate at which suspended matter was being added to the sediment (accounting for 92% of the increased metal biodeposition). Second, the material coming out of suspension had higher metal concentrations when zebra mussels were present (constituting 8% of the increased biodeposition). (author)

  19. Zebra Mussel Chemical Control Guide.

    Science.gov (United States)

    2000-01-01

    are 3 to 5 years. Zebra mussels are filter feeders, opening their shells to allow ingestion of particulates. When their sensitive chemoreceptors alert...used for oxidation of iron and manganese and to correct taste and odor problems in treated water because of its ability to produce oxidation reactions

  20. Effects of Room-Temperature Ionic Liquids on Zebra Mussels (Dreissena polymorpha)

    Science.gov (United States)

    Costello, D. M.; Bernot, R. J.; Lamberti, G. A.

    2005-05-01

    Zebra mussels (Dreissena polymorpha) are exotic bivalves that are widely distributed in eastern North America. We propose that this nuisance organism could serve as a model species for studies of aquatic toxicology. We tested zebra mussels response to room-temperature ionic liquids (ILs), which are being synthesized as environmentally friendly alternatives to volatile organic solvents. Volatile organic solvents contribute to atmospheric pollution and ozone depletion, whereas ILs are non-volatile and less harmful to the atmosphere. Although ILs would contribute significantly less to air pollution, little is known about their potential effects on aquatic ecosystems. In 72-hour toxicity tests, we determined the acute effects of three imidazolium-based ILs (1-butyl-3-methylimidazolium bromide (bmimBr), 1-hexyl-3-methylimidazolium bromide (hmimBr), and 1-octyl-3-methylimidazolium bromide (omimBr)) on the survival of zebra mussels. As alkyl chain length decreased, median lethal concentration (LC50) decreased from 1291 mg L-1 for bmimBr, to 105 mg L-1 for hmimBr, and 21.2 mg L-1 for omimBr. For bivalve mussels, the toxicities of these ILs are comparable to the toxicities of commonly used industrial solvents (e.g., toluene, benzene). This study presents a foundation for using zebra mussels in toxicity studies as well as possible models for less common Unionid mussels.

  1. Effects of shell morphology on mechanics of zebra and quagga mussel locomotion.

    Science.gov (United States)

    Peyer, Suzanne M; Hermanson, John C; Lee, Carol Eunmi

    2011-07-01

    Although zebra mussels (Dreissena polymorpha) initially colonized shallow habitats within the North American Great Lakes, quagga mussels (Dreissena bugensis) are becoming dominant in both shallow- and deep-water habitats. Shell morphology differs among zebra, shallow quagga and deep quagga mussels but functional consequences of such differences are unknown. We examined effects of shell morphology on locomotion for the three morphotypes on hard (typical of shallow habitats) and soft (characteristic of deep habitats) sedimentary substrates. We quantified morphology using the polar moment of inertia, a parameter used in calculating kinetic energy that describes shell area distribution and resistance to rotation. We quantified mussel locomotion by determining the ratio of rotational (K(rot)) to translational kinetic energy (K(trans)). On hard substrate, K(rot):K(trans) of deep quagga mussels was fourfold greater than for the other morphotypes, indicating greater energy expenditure in rotation relative to translation. On soft substrate, K(rot):K(trans) of deep quagga mussels was approximately one-third of that on hard substrate, indicating lower energy expenditure in rotation on soft substrate. Overall, our study demonstrates that shell morphology correlates with differences in locomotion (i.e. K(rot):K(trans)) among morphotypes. Although deep quagga mussels were similar to zebra and shallow quagga mussels in terms of energy expenditure on sedimentary substrate, their morphology was energetically maladaptive for linear movement on hard substrate. As quagga mussels can possess two distinct morphotypes (i.e. shallow and deep morphs), they might more effectively utilize a broader range of substrates than zebra mussels, potentially enhancing their ability to colonize a wider range of habitats.

  2. Predation and physical environment structure the density and population size structure of zebra mussels

    OpenAIRE

    Naddafi, Rahmat; Pettersson, Kurt; Eklöv, Peter

    2010-01-01

    The zebra mussel (Dreissena polymorpha) provides one example of successful invaders in novel environments. However, little attention has been devoted to exploring the factors regulating zebra mussel density and population size structure at the local scale. We tested effects of physicochemical factors and fish predation on the density of zebra mussels at several sites and between years in a natural lake. Water depth and roach (Rutilus rutilus) density were the most important variables affectin...

  3. Stoichiometric constraints do not limit successful invaders: zebra mussels in Swedish lakes.

    Science.gov (United States)

    Naddafi, Rahmat; Eklöv, Peter; Pettersson, Kurt

    2009-01-01

    Elemental imbalances of carbon (C): nitrogen (N): phosphorus (P) ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems. We examined the C:P and N:P ratios and the condition factor of a successful invader in lakes, the zebra mussel (Dreissena polymorpha), collected from two Swedish lakes. Concurrently, we analyzed the elemental composition of the food (seston) and tissue of the mussels in which nutrient composition of food and mussels varied over time. Zebra mussel condition factor was weakly related to the their own tissue N:P and C:P ratios, although the relation with the later ratio was not significant. Smaller mussels had relatively lower tissue N:P ratio and higher condition factor. There was no difference in C:P and N:P ratios between seston and mussels' tissues. Our results indicated that the variation in nutrient stoichiometry of zebra mussels can be explained by food quality and quantity. Our study suggests that fitness of invasive zebra mussels is not constrained by nutrient stoichiometry which is likely to be important for their proliferation in novel ecosystems. The lack of imbalance in C:P and N:P ratios between seston and mussels along with high tissue C:P ratio of the mussel allow them to tolerate potential P limitation and maintain high growth rate. Moreover, zebra mussels are able to change their tissue C:P and N:P ratios in response to the variation in elemental composition of their food. This can also help them to bypass potential nutrient stoichiometric constraints. Our finding is an important step towards understanding the mechanisms contributing to the success of exotic species from stoichiometric principles.

  4. Stoichiometric constraints do not limit successful invaders: zebra mussels in Swedish lakes.

    Directory of Open Access Journals (Sweden)

    Rahmat Naddafi

    Full Text Available Elemental imbalances of carbon (C: nitrogen (N: phosphorus (P ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems.We examined the C:P and N:P ratios and the condition factor of a successful invader in lakes, the zebra mussel (Dreissena polymorpha, collected from two Swedish lakes. Concurrently, we analyzed the elemental composition of the food (seston and tissue of the mussels in which nutrient composition of food and mussels varied over time. Zebra mussel condition factor was weakly related to the their own tissue N:P and C:P ratios, although the relation with the later ratio was not significant. Smaller mussels had relatively lower tissue N:P ratio and higher condition factor. There was no difference in C:P and N:P ratios between seston and mussels' tissues. Our results indicated that the variation in nutrient stoichiometry of zebra mussels can be explained by food quality and quantity.Our study suggests that fitness of invasive zebra mussels is not constrained by nutrient stoichiometry which is likely to be important for their proliferation in novel ecosystems. The lack of imbalance in C:P and N:P ratios between seston and mussels along with high tissue C:P ratio of the mussel allow them to tolerate potential P limitation and maintain high growth rate. Moreover, zebra mussels are able to change their tissue C:P and N:P ratios in response to the variation in elemental composition of their food. This can also help them to bypass potential nutrient stoichiometric constraints. Our finding is an important step towards understanding the mechanisms contributing to the success of exotic species from stoichiometric principles.

  5. Habitat engineering by the invasive zebra mussel Dreissena polymorpha (Pallas) in a boreal coastal lagoon: impact on biodiversity

    Science.gov (United States)

    Zaiko, Anastasija; Daunys, Darius; Olenin, Sergej

    2009-03-01

    Habitat engineering role of the invasive zebra mussel Dreissena polymorpha (Pallas) was studied in the Curonian lagoon, a shallow water body in the SE Baltic. Impacts of live zebra mussel clumps and its shell deposits on benthic biodiversity were differentiated and referred to unmodified (bare) sediments. Zebra mussel bed was distinguished from other habitat types by higher benthic invertebrate biomass, abundance, and species richness. The impact of live mussels on biodiversity was more pronounced than the effect of shell deposits. The structure of macrofaunal community in the habitats with >103 g/m2 of shell deposits devoid of live mussels was similar to that found within the zebra mussel bed. There was a continuous shift in species composition and abundance along the gradient ‘bare sediments—shell deposits—zebra mussel bed’. The engineering impact of zebra mussel on the benthic community became apparent both in individual patches and landscape-level analyses.

  6. Development of a molecular diagnostic system to discriminate Dreissena polymorpha (zebra mussel) and Dreissena bugensis (quagga mussel).

    Science.gov (United States)

    Hoy, Marshal S; Kelly, Kevin; Rodriguez, Rusty J

    2010-01-01

    A 3-primer PCR system was developed to discriminate invasive zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel. The system is based on: 1) universal primers that amplifies a region of the nuclear 28s rDNA gene from both species and 2) a species-specific primer complementary to either zebra or quagga mussel. The species-specific primers bind to sequences between the binding sites for the universal primers resulting in the amplification of two products from the target species and one product from the nontarget species. Therefore, nontarget products are positive amplification controls. The 3-primer system accurately discriminated zebra and quagga mussels from seven geographically distinct populations. Published 2009. This article is a US Government work and is the public domain in the USA.

  7. Effects of the exotic zebra mussel (Dreissena polymorpha) on metal cycling in Lake Erie

    Energy Technology Data Exchange (ETDEWEB)

    Klerks, P.L. [Univ. of Southwestern Louisiana, Dept. of Biology, Lafayette, Louisiana (United States)]. E-mail: klerks@usl.edu; Fraleigh, P.C.; Lawniczak, J.E. [Univ. of Toledo, Dept. of Biology, Toledo, Ohio (United States)

    1997-07-15

    This research demonstrated the impact of high densities of the zebra mussel (Dreissena polymorpha) on the cycling of copper, nickel, and zinc in a lake environment. Experiments with mussels on sedimentation traps in western Lake Erie and with mussels in flow-through tanks receiving Lake Erie water showed that zebra mussels remove metals from the water column, incorporate metals in their tissues, and deposit metals on the lake bottom. Removal of metals from the water column was estimated at 10-17%{center_dot}day{sup -1} of the amounts present. This material was largely deposited on the lake bottom; zebra mussels more than doubled the rate at which metals were being added to the lake bottom. Metal biodeposition rates were extremely high (e.g., 50 mg Zn{center_dot}m{sup -2}{center_dot}day{sup -1}) in high-turbidity areas with elevated metal levels. Two factors contributed to metal biodeposition by zebra mussels. First, their production of feces and pseudofeces increased the rate at which suspended matter was being added to the sediment (accounting for 92% of the increased metal biodeposition). Second, the material coming out of suspension had higher metal concentrations when zebra mussels were present (constituting 8% of the increased biodeposition). (author)

  8. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas

    International Nuclear Information System (INIS)

    Le Goff, J.; Gallois, J.; Pelhuet, L.; Devier, M.H.; Budzinski, H.; Pottier, D.; Andre, V.; Cachot, J.

    2006-01-01

    The purpose of this study was to examine PAH accumulation and bulky DNA adduct formation in the digestive gland of zebra mussels exposed in their habitat or in controlled laboratory conditions to complex mixture of PAH. DNA adducts were measured using a 32 P-postlabelling protocol with nuclease P1 enrichment adapted from Reddy and Randerath [Reddy, M.V., Randerath, K., 1986. Nuclease P1-mediated enhancement of sensitivity of 32 P-postlabelling test for structurally diverse DNA adducts. Carcinogenesis 7, 1543-1551]. Specimens collected in the upper part of the Seine estuary were shown to accumulate higher levels of PAH (up to 1.6 μg g -1 dry weight) in comparison to individuals from the reference site (0.053 μg g -1 dry weight). The former exhibited elevated levels of DNA adducts (up to 4.0/10 8 nucleotides) and higher diversity of individual adducts with five distinct spots being specifically detected in individuals originating from the Seine estuary. Zebra mussels exposed for 5 days to 0.01% (v/v) of organic extract of sediment from the Seine estuary were shown to accumulate high amounts of PAH (up to 138 μg g -1 dry weight) but exhibited relatively low levels of DNA adducts. Exposure to benzo[a]pyrene led to a dose-dependent accumulation of B[a]P (up to 7063 μg g -1 dry weight) and a clear induction of DNA adduct formation in the digestive gland of mussels (up to 1.13/10 8 nucleotides). Comparisons with other bivalves exposed to the same model PAH, revealed similar levels of adducts and comparable adduct profiles with a main adduct spot and a second faint one. This study clearly demonstrated that zebra mussels are able to biotransform B[a]P and probably other PAH into reactive metabolites with DNA-binding activity. This work also demonstrated the applicability of the nuclease P1 enhanced 32 P-postlabelling method for bulky adduct detection in the digestive gland of zebra mussels. DNA adduct measurement in zebra mussels could be a suitable biomarker to monitor

  9. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, J. [GRECAN, UPRES EA-1772, University of Caen, Caen (France); Gallois, J. [Laboratory F. Duncombe, Conseil General du Calvados, Caen (France); Pelhuet, L. [LPTC, UMR-5472 CNRS, University Bordeaux I, Bordeaux (France); Devier, M.H. [LPTC, UMR-5472 CNRS, University Bordeaux I, Bordeaux (France); Budzinski, H. [LPTC, UMR-5472 CNRS, University Bordeaux I, Bordeaux (France); Pottier, D. [GRECAN, UPRES EA-1772, University of Caen, Caen (France); Andre, V. [GRECAN, UPRES EA-1772, University of Caen, Caen (France); Cachot, J. [LEMA, UPRES EA-3222, IFRMP 23, University of Le Havre, 25 rue Philippe Lebon, B.P. 540, 76058 Le Havre Cedex (France)]. E-mail: jerome.cachot@univ-lehavre.fr

    2006-08-12

    The purpose of this study was to examine PAH accumulation and bulky DNA adduct formation in the digestive gland of zebra mussels exposed in their habitat or in controlled laboratory conditions to complex mixture of PAH. DNA adducts were measured using a {sup 32}P-postlabelling protocol with nuclease P1 enrichment adapted from Reddy and Randerath [Reddy, M.V., Randerath, K., 1986. Nuclease P1-mediated enhancement of sensitivity of {sup 32}P-postlabelling test for structurally diverse DNA adducts. Carcinogenesis 7, 1543-1551]. Specimens collected in the upper part of the Seine estuary were shown to accumulate higher levels of PAH (up to 1.6 {mu}g g{sup -1} dry weight) in comparison to individuals from the reference site (0.053 {mu}g g{sup -1} dry weight). The former exhibited elevated levels of DNA adducts (up to 4.0/10{sup 8} nucleotides) and higher diversity of individual adducts with five distinct spots being specifically detected in individuals originating from the Seine estuary. Zebra mussels exposed for 5 days to 0.01% (v/v) of organic extract of sediment from the Seine estuary were shown to accumulate high amounts of PAH (up to 138 {mu}g g{sup -1} dry weight) but exhibited relatively low levels of DNA adducts. Exposure to benzo[a]pyrene led to a dose-dependent accumulation of B[a]P (up to 7063 {mu}g g{sup -1} dry weight) and a clear induction of DNA adduct formation in the digestive gland of mussels (up to 1.13/10{sup 8} nucleotides). Comparisons with other bivalves exposed to the same model PAH, revealed similar levels of adducts and comparable adduct profiles with a main adduct spot and a second faint one. This study clearly demonstrated that zebra mussels are able to biotransform B[a]P and probably other PAH into reactive metabolites with DNA-binding activity. This work also demonstrated the applicability of the nuclease P1 enhanced {sup 32}P-postlabelling method for bulky adduct detection in the digestive gland of zebra mussels. DNA adduct measurement in

  10. Factorial microarray analysis of zebra mussel (Dreissena polymorpha: Dreissenidae, Bivalvia adhesion

    Directory of Open Access Journals (Sweden)

    Faisal Mohamed

    2010-05-01

    Full Text Available Abstract Background The zebra mussel (Dreissena polymorpha has been well known for its expertise in attaching to substances under the water. Studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. However, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown. Results In this study, we used a zebra mussel cDNA microarray previously developed in our lab and a factorial analysis to identify the genes that were involved in response to the changes of four factors: temperature (Factor A, current velocity (Factor B, dissolved oxygen (Factor C, and byssogenesis status (Factor D. Twenty probes in the microarray were found to be modified by one of the factors. The transcription products of four selected genes, DPFP-BG20_A01, EGP-BG97/192_B06, EGP-BG13_G05, and NH-BG17_C09 were unique to the zebra mussel foot based on the results of quantitative reverse transcription PCR (qRT-PCR. The expression profiles of these four genes under the attachment and non-attachment were also confirmed by qRT-PCR and the result is accordant to that from microarray assay. The in situ hybridization with the RNA probes of two identified genes DPFP-BG20_A01 and EGP-BG97/192_B06 indicated that both of them were expressed by a type of exocrine gland cell located in the middle part of the zebra mussel foot. Conclusions The results of this study suggested that the changes of D. polymorpha byssogenesis status and the environmental factors can dramatically affect the expression profiles of the genes unique to the foot. It turns out that the factorial design and analysis of the microarray experiment is a reliable method to identify the influence of multiple factors on the expression profiles of the probesets in the microarray; therein it provides a powerful tool to reveal the mechanism of zebra mussel underwater attachment.

  11. Factorial microarray analysis of zebra mussel (Dreissena polymorpha: Dreissenidae, Bivalvia) adhesion.

    Science.gov (United States)

    Xu, Wei; Faisal, Mohamed

    2010-05-28

    The zebra mussel (Dreissena polymorpha) has been well known for its expertise in attaching to substances under the water. Studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. However, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown. In this study, we used a zebra mussel cDNA microarray previously developed in our lab and a factorial analysis to identify the genes that were involved in response to the changes of four factors: temperature (Factor A), current velocity (Factor B), dissolved oxygen (Factor C), and byssogenesis status (Factor D). Twenty probes in the microarray were found to be modified by one of the factors. The transcription products of four selected genes, DPFP-BG20_A01, EGP-BG97/192_B06, EGP-BG13_G05, and NH-BG17_C09 were unique to the zebra mussel foot based on the results of quantitative reverse transcription PCR (qRT-PCR). The expression profiles of these four genes under the attachment and non-attachment were also confirmed by qRT-PCR and the result is accordant to that from microarray assay. The in situ hybridization with the RNA probes of two identified genes DPFP-BG20_A01 and EGP-BG97/192_B06 indicated that both of them were expressed by a type of exocrine gland cell located in the middle part of the zebra mussel foot. The results of this study suggested that the changes of D. polymorpha byssogenesis status and the environmental factors can dramatically affect the expression profiles of the genes unique to the foot. It turns out that the factorial design and analysis of the microarray experiment is a reliable method to identify the influence of multiple factors on the expression profiles of the probesets in the microarray; therein it provides a powerful tool to reveal the mechanism of zebra mussel underwater attachment.

  12. Modelling the effects of diving ducks on zebra mussels Dreissena polymorpha in lakes

    NARCIS (Netherlands)

    Nes, van E.H.; Noordhuis, R.; Lammens, E.H.R.R.; Portielje, R.; Reeze, B.; Peeters, E.T.H.M.

    2008-01-01

    An individual-based model describing the growth of zebra mussels (Dreissena polymorpha) is presented. The model is spatially explicit and predicts length¿frequency distributions of zebra mussels. The parameters and model inputs with the strongest effect on the model outcomes were identified using a

  13. Metal contamination in zebra mussels (Dreissena polymorpha) along the St. Lawrence River.

    Science.gov (United States)

    Kwan, K H Michael; Chan, Hing Man; de Lafontaine, Yves

    2003-01-01

    In order to evaluate the use of zebra mussels as biomonitors for metal bioavailability in the St. Lawrence River, we tested the hypothesis that the concentrations of 11 metals in zebra mussels vary significantly between sites along the river and that the season of collection and body size affect metal bioaccumulation. Mussels were collected at 14 sites during June 1996 and at monthly intervals at one site. Specimens were grouped in three size classes and their soft tissue was analyzed for As, Ca, Cd, Cr, Hg, Mn, Ni, Pb, Se, and Zn. Significant size effects were found for Ca, Cd, Cr, Cu, Ni and Zn. Spatial and seasonal variations in bioconcentration were significant for all metals. Spatial patterns in contamination that corresponded to known point sources of pollution or hydrology of the river were identified by principal component analysis. Seasonal variations can be attributed to the reproductive cycle of mussels and hydrological variability of the river. In comparison with values reported for zebra mussels in other contaminated sites in North America and Europe, levels of metal in the St. Lawrence River are low or intermediate. Our results show that when controlled for size and seasonal effects, zebra mussels represent a useful biomonitor for metal availability in the river and may offer an interesting alternative to native mussels and fish for such a role. Local contamination by some toxic metals is still a cause for concern in the St. Lawrence River.

  14. Optimal Management of a Potential Invader: The Case of Zebra Mussels in Florida

    OpenAIRE

    Lee, Donna J.; Adams, Damian C.; Rossi, Frederick J.

    2007-01-01

    Dominant users of Lake Okeechobee water resources are agricultural producers and recreational anglers. These uses will be directly affected, should the lake become infested with zebra mussels. We employ a probabilistic bioeconomic simulation model to estimate the potential impact of zebra mussels on consumptive water uses, recreational angling, and wetland ecosystem services under alternative public management scenarios. Without public management, the expected net economic impact from zebra m...

  15. Bioaccumulation of human waterborne protozoa by zebra mussel (Dreissena polymorpha): interest for water biomonitoring.

    Science.gov (United States)

    Palos Ladeiro, M; Aubert, D; Villena, I; Geffard, A; Bigot, A

    2014-01-01

    Cryptosporidium parvum, Giardia duodenalis and Toxoplasma gondii are ubiquitous pathogens, which waterborne transmission has been largely demonstrated. Since they can be found in various watercourses, interactions with aquatic organisms are possible. Protozoan detection for watercourses biomonitoring is currently based on large water filtration. The zebra mussel, Dreissena polymorpha, is a choice biological model in ecotoxicological studies which are already in use to detect chemical contaminations in watercourses. In the present study, the zebra mussel was tested as a new tool for detecting water contamination by protozoa. In vivo exposures were conducted in laboratory experiments. Zebra mussel was exposed to various protozoan concentrations for one week. Detection of protozoa was realized by Taqman real time qPCR. Our experiments evidenced C. parvum, G. duodenalis and T. gondii oocyst bioaccumulation by mussels proportionally to ambient contamination, and significant T. gondii prevalence was observed in muscle tissue. To our knowledge, this is the first study that demonstrates T. gondii oocyst accumulation by zebra mussel. The results from this study highlight the capacity of zebra mussels to reveal ambient biological contamination, and thus to be used as a new effective tool in sanitary biomonitoring of water bodies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Efficacy of Pseudomonas fluorescens strain CL145A spray dried powder for controlling zebra mussels adhering to native unionid mussels within field enclosures

    Science.gov (United States)

    Luoma, James A.; Weber, Kerry L.; Severson, Todd J.; Mayer, Denise A.

    2015-01-01

    The efficacy of a commercially prepared spray dried powder (SDP) formulation of Pseudomonas fluorescens (strain CL145A) was evaluated for removing zebra mussels (Dreissena polymorpha) adhering to a population of unionid mussels in Lake Darling (Alexandria, Minnesota). Two groups of unionid mussels were used in the study. Unionid mussels were collected near the test area, weighed, photographed, individually tagged, and randomly allocated to one of nine test enclosures in equal proportions and then divided into two groups. The first group of unionid mussels (Group 1, n = 5 per test enclosure) were indiscriminately selected from each test enclosure and used to estimate the number of zebra mussels adhering to unionid mussels prior to exposure. The second group of unionid mussels (Group 2, n = 22 per test enclosure) were used to evaluate the efficacy of SDP for removal of adhering zebra mussels. Both Group 1 and Group 2 mussels were used to evaluate the effects of SDP exposure on unionid mussel survival.

  17. Monitoring of zebra mussels in the Shannon-Boyle navigation, other

    OpenAIRE

    Minchin, D.; Lucy, F.; Sullivan, M.

    2002-01-01

    The zebra mussel (Dreissena polymorpha) population has been closely monitored in Ireland following its discovery in 1997. The species has spread from lower Lough Derg, where it was first introduced, to most of the navigable areas of the Shannon and other interconnected navigable waters. This study took place in the summers of 2000 and 2001 and investigated the relative abundance and biomass of zebra mussels found in the main navigations of the Shannon and elsewhere in rivers, canals and lakes...

  18. Newspaper Coverage of Zebra Mussels in North America : A Case of "Afghanistanism"?

    OpenAIRE

    Roush, Donny; Fortner, Rosanne

    1996-01-01

    Few environmental issues have arisen so abruptly, spread so rapidly, and been so clearly linked to human activity as has the introduction of nonindigenous zebra mussels to the surface freshwater of North America. This research examines communication patterns in information about zebra mussels as an example of how the mass media deal with threats to the environment.

  19. Use of on-site refugia to protect unionid populations from zebra mussel-induced mortality

    Science.gov (United States)

    Nichols, S. Jerrine; Black, M. Glen; Allen, Jeffrey D.

    2000-01-01

    Protecting unionid populations as zebra mussels spread into inland waterways has relied mainly on relocating at-risk animals into aquaculture facilities. While such relocations are the only viable management technique for some populations, facility availability is limited, leaving many unionids facing extirpation. Another management strategy is in-situ protection either by enhancing natural refugia or by creating managed refugia. We have reviewed all reports of natural refugia and found that refugia for unionids can be found in many areas. There are many habitats where zebra mussel colonization has been limited, or of a temporary nature. Within zebra mussel infested areas, unionid communities continue to survive in some shallow water sites such as estuaries, deltas, and lake-connected wetlands. Managed refugia can be created in areas where natural refugia do not exist. We present a case study on recent efforts to create refugia in an area with rapidly expanding zebra mussel populations. Preliminary analysis of unionid body condition indicates that removal of encrusted zebra mussels only once a year can improve unionid condition factors and decrease mortality. Natural and managed refugia can provide an additional conservation management option in some areas.

  20. Seasonal effects of the zebra mussel (Dreissena polymorpha) on sediment denitrification rates in Pool 8 of the Upper Mississippi River

    Science.gov (United States)

    Bruesewitz, Denise A.; Tank, Jennifer L.; Bernot, Melody J.; Richardson, William B.; Strauss, Eric A.

    2006-01-01

    Zebra mussels (Dreissena polymorpha) have altered the structure of invaded ecosystems and exhibit characteristics that suggest they may influence ecosystem processes such as nitrogen (N) cycling. We measured denitrification rates seasonally on sediments underlying zebra mussel beds collected from the impounded zone of Navigation Pool 8 of the Upper Mississippi River. Denitrification assays were amended with nutrients to characterize variation in nutrient limitation of denitrification in the presence or absence of zebra mussels. Denitrification rates at zebra mussel sites were high relative to sites without zebra mussels in February 2004 (repeated measures analysis of variance (RM ANOVA), p = 0.005), potentially because of high NO3-N variability from nitrification of high NH4+ zebra mussel waste. Denitrification rates were highest in June 2003 (RM ANOVA, p 3-N concentrations during the study (linear regression, R2 = 0.72, p p ≤ 0.01). Examining how zebra mussels influence denitrification rates will aid in developing a more complete understanding of the impact of zebra mussels and more effective management strategies of eutrophic waters.

  1. Lessons learned in over 100 zebra mussel control applications at industrial facilities

    Energy Technology Data Exchange (ETDEWEB)

    McGough, C.M.; Gilland, P.H.; Muia, R.A. [Calgon Corp., Pittsburgh, PA (United States)

    1998-12-31

    Since their introduction into US waterways, Zebra Mussels (Dreissena polymorphae) have spread rapidly throughout the Great Lakes and Mississippi regions. These mussels have continued to colonize the intake pipes of industrial water supplies and water distribution systems throughout the affected areas. Their colonization has compromised plant safety and production efficiency, and steadily increased costs to water users. The design of each industrial plant water distribution system is unique. A comprehensive zebra mussel control strategy using the best available options must be considered in each specific situation. This paper discusses the successful use of one strategy (a quaternary ammonia-based molluscicide) in the battle against zebra mussels. The commercial life cycle of an industrial molluscicide began with initial toxicity screening in the laboratory. The evaluation continued at plant sites through field trials and applications. Lessons learned from these experiences helped direct the efforts toward the development of a second generation program.

  2. Zebra mussels enter the compost pile

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    Zebra mussels, introduced accidentally into the Great Lakes, are overpopulating at phenomenal rates, especially in Lake Erie, where they damage oyster beds, foster excessive algae growth and cling to boats. They also clog the intake pipes of city water systems and power generating plants. The expense of cleaning intake screens is considerable, since they have to be physically removed and cleaned. Then the mussels must be disposed of, costing some power plants as much as $50,000 a year to landfill, says Wayne Koser of the Michigan Department of Natural Resources.

  3. Bioaccumulation and effects of perfluorinated compounds (PFCs) in zebra mussels (Dreissena polymorpha).

    Science.gov (United States)

    Fernández-Sanjuan, María; Faria, Melissa; Lacorte, Silvia; Barata, Carlos

    2013-04-01

    Perfluorinated chemicals (PFCs) have been used for many years in numerous industrial products and are known to accumulate in organisms. A recent survey showed that tissue levels of PFCs in aquatic organisms varied among compounds and species being undetected in freshwater zebra mussels Dreissena polymorpha. Here we studied the bioaccumulation kinetics and effects of two major PFCs, perfluorooctane sulfonic acid compound (PFOS) and perfluorooctanoic acid (PFOA), in multixenobiotic transporter activity (MXR) and filtration and oxygen consumption rates in zebra mussel exposed to a range of concentrations of a PCF mixture (1-1,000 μg/L) during 10 days. Results indicate a low potential of the studied PFCs to bioaccumulate in zebra mussel tissues. PFCs altered mussel MXR transporter activity being inhibited at day 1 but not at day 10. Bioaccumulation kinetics of PFCs were inversely related with MXR transporter activity above 9 ng/g wet weight and unrelated at tissue concentration lower than 2 ng/g wet weight suggesting that at high tissue concentrations, these type of compounds may be effluxed out by MXR transporters and as a result have a low potential to be bioaccumulated in zebra mussels. Oxygen consumption rates but not filtering rates were increased in all exposure levels and periods indicating that at environmental relevant concentrations of 1 μg/L, the studied PFCs enhanced oxidative metabolism of mussels. Overall, the results obtained in this study confirm previous findings in the field indicating that an important fraction of PFC accumulated in mussel tissues is eliminated actively by MXR transporters or other processes that are metabolically costly.

  4. Predicting the spread of aquatic invaders: insight from 200 years of invasion by zebra mussels.

    Science.gov (United States)

    Karatayev, Alexander Y; Burlakova, Lyubov E; Mastitsky, Sergey E; Padilla, Dianna K

    2015-03-01

    Understanding factors controlling the introduction and spread of species is crucial to improving the management of both natural populations and introduced species. The zebra mussel, Dreissena polymorpha, is considered the most aggressive freshwater invader in the Northern Hemisphere, and is a convenient model system for invasion biology, offering one of the best aquatic examples for examining the invasion process. We used data on 553 of the 1040 glacial lakes in the Republic of Belarus that were examined for the presence of zebra mussels. We used these data to build, test, and construct modified models to predict the spread of this invader, including selection of important parameters that could limit the spread of this invader. In spite of 200 years of continuous invasion, by 1996, zebra mussels were found in only 16.8% of all lakes studied. Of those lakes without zebra mussels in 1996, 66% were predicted to be susceptible to invasion by zebra mussels in the future, and 33% were predicted to be immune to successful invasion due to their water chemistry. Eighty lakes free of zebra mussels in 1996 were reexamined from 1997 to 2008. Of these, zebra mussels successfully invaded an additional 31 lakes, all of which were classified initially as suitable for zebra mussels; none of the lakes previously classified as unsuitable were invaded. We used the Random Forests classification algorithm with 16 environmental variables to determine the most important factors that differed between invaded lakes and those lakes suitable for invasion that have not yet been invaded. Distance to the nearest infested lakes was found to be the most important variable, followed by the lake area, color, average depth, and concentration of chloride, magnesium, and bicarbonate. This study provides a useful approach for predicting the spread of an invader across a landscape with variable habitat suitability that can be applied to a variety of species and systems.

  5. Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults

    International Nuclear Information System (INIS)

    Navarro, Anna; Faria, Melissa; Barata, Carlos; Pina, Benjamin

    2011-01-01

    Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

  6. Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Anna; Faria, Melissa; Barata, Carlos [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain); Pina, Benjamin, E-mail: bpcbmc@cid.csic.e [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain)

    2011-01-15

    Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

  7. Zebra Mussel Research Technical Notes. Section 1 - Environmental Testing

    National Research Council Canada - National Science Library

    1998-01-01

    ...: Biology, Ecology, and Recommended Control Strategies, Larval Monitoring in a Chlorine Treatment Program to Prevent Zebra Mussel Settlement in Hydropower Facilities, Louisville District Initiates...

  8. Pseudomonas fluorescens strain CL145A - a biopesticide for the control of zebra and quagga mussels (Bivalvia: Dreissenidae).

    Science.gov (United States)

    Molloy, Daniel P; Mayer, Denise A; Gaylo, Michael J; Morse, John T; Presti, Kathleen T; Sawyko, Paul M; Karatayev, Alexander Y; Burlakova, Lyubov E; Laruelle, Franck; Nishikawa, Kimi C; Griffin, Barbara H

    2013-05-01

    Zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis) are the "poster children" of high-impact aquatic invasive species. In an effort to develop an effective and environmentally acceptable method to control their fouling of raw-water conduits, we have investigated the potential use of bacteria and their natural metabolic products as selective biological control agents. An outcome of this effort was the discovery of Pseudomonas fluorescens strain CL145A - an environmental isolate that kills these dreissenid mussels by intoxication (i.e., not infection). In the present paper, we use molecular methods to reconfirm that CL145A is a strain of the species P. fluorescens, and provide a phylogenetic analysis of the strain in relation to other Pseudomonas spp. We also provide evidence that the natural product lethal to dreissenids is associated with the cell wall of P. fluorescens CL145A, is a heat-labile secondary metabolite, and has degradable toxicity within 24 h when applied to water. CL145A appears to be an unusual strain of P. fluorescens since it was the only one among the ten strains tested to cause high mussel mortality. Pipe trials conducted under once-through conditions indicated: (1) P. fluorescens CL145A cells were efficacious against both zebra and quagga mussels, with high mortalities achieved against both species, and (2) as long as the total quantity of bacterial cells applied during the entire treatment period was the same, similar mussel mortality could be achieved in treatments lasting 1.5-12.0 h, with longer treatment durations achieving lower mortalities. The efficacy data presented herein, in combination with prior demonstration of its low risk of non-target impact, indicate that P. fluorescens CL145A cells have significant promise as an effective and environmentally safe control agent against these invasive mussels. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Comparative biology of zebra mussels in Europe and North America: an overview

    Science.gov (United States)

    Mackie, Gerald L.; Schloesser, Don W.

    1996-01-01

    SYNOPSIS. Since the discovery of the zebra mussel, Dreissena polymorpha, in the Great Lakes in 1988 comparisons have been made with mussel populations in Europe and the former Soviet Union. These comparisons include: Population dynamics, growth and mortality rates, ecological tolerances and requirements, dispersal rates and patterns, and ecological impacts. North American studies, mostly on the zebra mussel and a few on a second introduced species, the quagga mussel, Dreissena bugensis, have revealed some similarities and some differences. To date it appears that North American populations of zebra mussels are similar to European populations in their basic biological characteristics, population growth and mortality rates, and dispersal mechanisms and rates. Relative to European populations differences have been demonstrated for: (1) individual growth rates; (2) life spans; (3) calcium and pH tolerances and requirements; (4) potential distribution limits; and (5) population densities of veligers and adults. In addition, studies on the occurrence of the two dreissenid species in the Great Lakes are showing differences in their modes of life, depth distributions, and growth rates. As both species spread throughout North America, comparisons between species and waterbodies will enhance our ability to more effectively control these troublesome species.

  10. Zebra mussels (Dreissena polymorpha) in Ireland, AFLP-fingerprinting and boat traffic both indicate an origin from Britain

    NARCIS (Netherlands)

    Pollux, B.J.A.; Minchin, D.; Van der Velde, G.; Van Alen, T.; Moon-Van der Staay, S.Y.; Hackstein, J.

    2003-01-01

    The zebra mussel (Dreissena polymorpha) is an aquatic nuisance species that invaded Ireland around 1994. We studied the invasion of the zebra mussel combining field surveys and genetic studies, to determine the origin of invasion and the vector of introduction. Field surveys showed that live zebra

  11. Learning to live with zebra mussels

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Fingernail-sized mollusks from Europe pose a threat to Clean Coal Technology demonstration projects. This article describes the mussels life cycle and behavior, fouling of utility water systems, and effective methods of control, including chemical treatment, thermal treatment, mechanical treatment, and coatings

  12. Identification of larvae: The zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena rosteriformis bugensis), and Asian clam (Corbicula fluminea)

    Science.gov (United States)

    Nichols, S. Jerrine; Black, M.G.

    1994-01-01

    There are presently four freshwater bivalves in the United States that produce larvae or veligers commonly found in the water column: two forms of Asian clams and two species of dreissenids. Portions of the geographic range of three of these bivalves, one species of Asian clam (Corbicula fluminea), zebra mussels (Dreissena polymorpha), and quagga mussels (Dreissena rosteriformis bugensis), overlap, causing problems with larval identification. To determine which characteristics can be used to separate larval forms, adult Asian clams, quaggas, and zebra mussels were brought into the laboratory and induced to spawn, and the resulting larvae were reared. Hybrids between quaggas and zebra mussels were also produced, but not reared to maturity. Characteristics allowing for the most rapid and accurate separation of larvae were hinge length, shell length/height, shell shape, shell size, and the presence or absence of a foot and velum. These characteristics were observed in laboratory-reared larvae of known parentage and field-caught larvae of unknown parentage. In most cases, larvae of the Asian clam can be readily separated from those produced by either type of dreissenid on the basis of shell size and presence of a foot. Separating the gametes and embryos of the two types of dreissenids is not possible, but after shell formation, most of the larval stages can be distinguished. Hinge length, shell length/height, and the similarity in size of the shell valves can be used to separate straight-hinged, umbonal, pediveliger, and plantigrade larvae. Quagga × zebra mussel hybrids show characteristics of both parents and are difficult to identify.

  13. Increase deposition of organic matter, polychlorinated biphenyls, and cadmium by zebra mussels (Dreissena polymorpha) in western Lake Erie

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, E. P; Mackie, G. L. [Guelph Univ., Dept. of Zoology, ON (Canada)

    1998-05-01

    Biodeposition of polychlorinated biphenyls (PCBs)and cadmium by zebra mussels in the western basin of Lake Erie was investigated using sediment traps, and compared to natural rates of sedimentation. On a per unit area of organic matter, deposition rates by zebra mussels up to eight to ten times higher than natural rates of sedimentation were found. These results suggest that zebra mussels are altering contaminant movement in western Lake Erie. At the same time, it was also suggested that the net effect of biodeposition may not be as great as shown in this study since only the effects of zebra mussels on the flux of the contaminants was examined and the re-suspension factor was not considered. It was recommended that to better understand the overall effects of zebra mussels on contaminant dynamics in aquatic environments, future studies should incorporate the re-suspension factors. 27 refs., 8 tabs., 3 figs.

  14. Assimilation and depuration of microcystin–LR by the zebra mussel, Dreissena polymorpha

    NARCIS (Netherlands)

    Pires, L.M.D.; Karlsson, K.M.; Meriluoto, J.A.O.; Kardinaal, E.A.; Visser, P.M.; Siewertsen, K.; Van Donk, E.; Ibelings, B.W.

    2004-01-01

    Zebra mussels (Dreissena polymorpha) are an important component of the foodweb of shallow lakes in the Netherlands, amongst others in Lake IJsselmeer, an international important wetland. Large numbers of ducks feed on these mussels in autumn and winter. The mussels are filter feeders and are exposed

  15. Accumulation of a low pathogenic avian influenza virus in zebra mussels (Dreissena polymorpha).

    Science.gov (United States)

    Stumpf, Petra; Failing, Klaus; Papp, Tibor; Nazir, Jawad; Böhm, Reinhard; Marschang, Rachel E

    2010-12-01

    In order to investigate the potential role of mussels as a vector of influenza A viruses, we exposed zebra mussels (Dreissena polymorpha) to natural lake water containing a low pathogenic H5N1 avian influenza virus. Mussels were kept in water containing virus for 48 hr, then transferred into fresh water for another 14 days. Virus detection in mussels and water samples was performed by quantitative real-time reverse transcriptase-PCR (qRRT-PCR) and egg culture methods. Virus uptake was detected in all of the mussel groups that were exposed to virus. Even after 14 days in fresh water, virus could still be detected in shellfish material by both qRRT-PCR and egg culture methods. The present study demonstrates that zebra mussels are capable of accumulating influenza A viruses from the surrounding water and that these viruses remain in the mussels over an extended period of time.

  16. Application experience with ADBAC/DGH cationic surfactants for zebra mussel control in a nuclear service water system

    International Nuclear Information System (INIS)

    Jung, W.R.; Lacy, J.R.; Post, R.

    1992-01-01

    In response to the introduction and rapid growth of the zebra mussel population in the Great Lakes and the issuance of NRC Generic Letter 89-13 (Service Water Problems Affecting Safety-Related Equipment). A midwest nuclear station instituted a zebra mussel monitoring and control program. The nuclear station uses Lake Michigan as a cooling water source for two 1,100 MW Westinghouse 4-loop design, pressurized water reactors (PWR). Two years of monitoring indicated a growth in zebra mussel population from 0.5 organisms/m 2 in July 1990 to 100 organisms/m 2 by November 1990. This rapid increase indicated an urgent need for viable methods of zebra mussel control to protect the plant's essential service water (ESW) and non-essential service water (NESW) systems. In April 1991, the station formulated a plan that combined increased system inlet temperature with targeted application of a proprietary product containing two cationic surfactants, ADBAC/DGH. Sidestream biomonitoring boxes were seeded with zebra mussels and observed as a measure of the efficacy of the treatment. Where recommended dosages and duration were maintained, 100% control was achieved

  17. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  18. Zebra mussels (Dreissena polymorpha) limit food for larval fish (Pimephales promelas) in turbulent systems: A bioenergetics analysis

    Science.gov (United States)

    Bartsch, L.A.; Richardson, W.B.; Sandheinrich, M.B.

    2003-01-01

    We conducted a factorial experiment, in outdoor mesocosms, on the effects of zebra mussels and water column mixing (i.e., turbulence) on the diet, growth, and survival of larval fathead minnows (Pimephales promelas). Significant (P zebra mussels, whereas mortality was 37% in treatment with turbulence and 17% and 18% in the zebra mussels treatment, and the control, respectively. The size of individual fish was significantly different among treatments at the end of the experiment and was inversely related to survival. Levels of trophic resources (i.e., phyto and zooplankton) varied among treatments and were treatment specific. Turbulent mixing facilitated removal of phytoplankton by zebra mussels by making the entire water column of the tanks available to these benthic filter feeders. Early in the experiment (Day = 0 to 14) the physical process of turbulent mixing likely caused a reduction in standing stocks of zooplankton. The interactive effect of turbulence and mussels reduced copepod and rotifer stocks, through physical processes and through filtration by zebra mussels, relative to the turbulence treatment. The reductions in the number of total zooplankton in the turbulent mixing mesocosms and the further reduction of rotifer and copepod in the turbulence and mussels treatment coincided with a period of increased reliance of larval fathead minnows on these prey. Estimates of consumption from bioenergetics modeling and measured prey standing stocks indicated caloric resources of suitable prey in turbulence treatments during the early weeks of the experiment were insufficient to prevent starvation. Early mortality in the turbulence and mussels treatment likely released surviving fish from intense intraspecific competition and resulted in higher individual growth rates. A combination of high abundance of zebra mussels in an environment with a well-mixed water column can have significant effects on larval fish survival and growth.

  19. Filtration effects of zebra mussels on pathogens and total bacterial burden in the Odra Lagoon (South Baltic).

    Science.gov (United States)

    Daeschlein, G; Fenske, C; Scholz, S; Dahlke, S; Jünger, M; Kramer, A

    2015-01-01

    As a result of their mode of filter feeding, zebra mussels (Dreissena polymorpha Pall.) have been observed to purify natural water bodies and in vitro. Therefore, the possibility of using zebra mussels for water purification was investigated in a slightly brackish water body of a large lagoon. In this study, water samples were taken above, near and at distance from zebra mussel beds (MB) in the Odra Lagoon in North East Germany. Near typical bacterial species like Aeromonas spp. pathogenic bacteria with potential relation to hospital wastewater pollution (Burkholderia cepacia, Staphylococcus aureus, Weeksella spp.) were detected. There were no correlations found between either total bacteria or pathogens and distance to MB and no antimicrobial effect of the mussels could be deduced. For bioremediation in larger water bodies like lagoons, natural zebra MB do not seem to play a major antimicrobial role and the effect of artificial mussel grids especially against hospital pathogens should be investigated.

  20. ZEBRA MUSSEL COLONIZATION OF RUSTY CRAYFISH IN GREEN BAY, LAKE MICHIGAN

    Science.gov (United States)

    In August, 1995 six rusty crayfish colonized with zebra mussels were captured in small-meshed fyke-nets sets set apart as of a fish sampling effort at Peter's Marsh and Long-Tail Point Wetland in lower Green Bay. Mussels colonized virtually all areas of the crayfish bodies, but ...

  1. Cultivation of zebra mussels (Dreissena polymorpha) within their invaded range to improve water quality in reservoirs.

    Science.gov (United States)

    McLaughlan, C; Aldridge, D C

    2013-09-01

    Algal and cyanobacterial blooms in reservoirs are driven by nutrient enrichment and may present economic and conservation challenges for water managers. Current approaches such as suppression of algal growth with barley straw, ferric dosing or manipulation of fish stocks have not yielded long term successes. A possibility that has sparked growing interest is the encouragement and cultivation of natural filter feeders, such as mussels, which remove suspended matter from the water and reduce nutrient levels through biodeposition and assimilation. This review focusses on the zebra mussel (Dreissena polymorpha) as a tool for enhancement of water quality in reservoirs. Native to the Ponto-Caspian region, this species has invaded many lakes and reservoirs across North America and Western Europe, where it occurs in very high densities. While purposeful introduction of a non-native species into new sites is socially unacceptable, we investigate the possible benefits of encouraging increased abundance of zebra mussels in sites where the species is already established. We estimate that the annual nitrogen and phosphorus input into a large UK reservoir (Grafham Water) could be assimilated into zebra mussel biomass by encouraging settlement onto 3075 m and 1400 m of commercial mussel ropes, respectively. While zebra mussel cultivation has an incredible capacity to push eutrophic systems towards a clear water state, there are many risks associated with encouraging an invasive species, even within sites where it has already established. The zebra mussel is a prominent biofouler of native unionid mussels and raw water pipes, it changes the physical characteristics of the places it inhabits, in sites low in phosphorus it can be responsible for toxic cyanobacterial blooms, it alters nutrient cycling and community structure and it can have negative impacts on amenity value. Increased propagule pressure from elevated numbers of veliger larvae in the water column may increase the risk

  2. Bioassessment of mercury, cadmium, polychlorinated biphenyls, and pesticides in the Upper Mississippi River with zebra mussels (Dreissena polymorpha)

    Energy Technology Data Exchange (ETDEWEB)

    Cope, W.G.; Bartsch, M.R.; Rada, R.G.; Balogh, S.J.; Rupprecht, J.E.; Young, R.D.; Johnson, D.K.

    1999-12-15

    Zebra mussels (Dreissena polymorpha) were sampled from artificial substrates deployed from May 30 to October 19, 1995, at 19 locks and dams from Minneapolis, MN, to Muscatine, IA. Analyses of composite tissue samples of zebra mussels revealed accumulation of mercury (Hg), cadmium (Cd), and polychlorinated biphenyls (PCBs) during a 143-d exposure period. Concentrations of total Hg ranged from 2.6 to 6.1 ng/g wet weight and methylmercury (CH{sub 3}Hg) from 1.0 to 3.3 ng/g wet weight. About 50% of the mean total Hg in zebra mussels was CH{sub 3}Hg. Cadmium ranged from 76 to 213 ng/g wet weight. Concentrations of total PCBs in zebra mussels varied longitudinally, but the composition of PCB congeners was similar throughout the river. Chlordane and dieldrin were the only two pesticides detected of the 15 analyzed. Zebra mussels are sentinels of contaminant bioavailability in the Upper Mississippi River and may be an important link in the trophic transfer of contaminants in the river because of their increasing importance in the diets of certain fish and waterfowl.

  3. Robotic removal of zebra mussel accumulations in a nuclear power plant screenhouse

    International Nuclear Information System (INIS)

    Kotler, S.R.; Mallen, E.C.; Tamms, K.M.

    1995-01-01

    Zebra mussel accumulations in the power plant intake system have increased over the last four years and have become a maintenance issue. Several treatment methods have been used, including mechanical cleaning by divers. This is limited to areas of relatively low flow velocity. Various sections of the screenhouse are not accessible except during an outage or when one of the intake tunnels can be otherwise be blocked and flow reduced. In addition, diver services are relatively costly. For the above reasons, the Indiana Michigan Power Co., Cook Nuclear Plant, contracted with ARD Environmental Inc. to develop and test a robotic system as an alternative to cleaning by divers. The first phase of this project addressed the requirement to clean the screenhouse floor in all areas, including those with high flow velocity. Subsequent phases will address robotic cleaning of other areas of the intake and the screenhouse structures. The objectives of the project were to: (1) Demonstrate the ability to deploy and retrieve a modified XT1000 vehicle in the inlet bay and screen bays; (2) Remove the accumulations of zebra mussels and possibly other pumpable material from the floor; (3) Reduce or eliminate the need for diver services and reduce overall cost of removing accumulations of zebra mussels; and, (4) Critique operations and develop recommendations for further enhancements to the robotic equipment and materials handling system. Implementation of the operating plan commenced on September 8, 1994, and was completed on October 7, 1994. The project demonstrated that robotic techniques are an efficient and cost effective alternative to diver operations for mechanical removal of zebra mussels. In particular, the robotic system was able to operate effectively in the high flow velocity areas including those at the intake tunnels. The ability to operate in the high flow areas means that zebra mussel removal may take place at any time, without affecting normal plant operations

  4. Differentiation of sympatric zebra and quagga mussels in ecotoxicological studies: A comparison of morphometric data, gene expression, and body metal concentrations.

    Science.gov (United States)

    Kerambrun, E; Delahaut, L; Geffard, A; David, E

    2018-06-15

    The zebra mussel is among the best studied freshwater molluscs in ecotoxicology, but information on the quagga mussel is lacking. Considering its potential spread, we selected a river in France in which zebra and quagga mussels coexisted, and then we used genetic markers to differentiate the two species and compared morphological parameters. cDNA sequencing assays of ten genes already used in zebra mussels were performed on quagga mussels to obtain functional specific primers. Then we analyzed the expression of genes involved in cellular metabolic activities (Cytochrome-c-oxidase - cox, and ATP synthase - atp), detoxification processes (Glutathione-S-Transferase - gst), oxidative stress (Catalase - cat), and digestive functions (Amylase - amy) on the two species. Whereas morphometric analysis underlined similarities in shape between the two species, relative gene expression profiles and metal concentrations evidenced strong differences. Quagga mussels notably presented half as high concentrations in Cd and Pb, two particularly toxic elements, as zebra mussels. These results imply that i) particular attention should be paid to properly distinguish the two species considering their similar external appearance, and ii) zebra mussels cannot be replaced by quagga mussels in ecotoxicological studies without preliminary investigations on biomarker response patterns. To our knowledge, this study is the first to have undertaken such an approach in gene expression analysis in quagga mussels, and more generally to have compared such biomarker responses of zebra and quagga mussels in the field. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Prevention and control of zebra mussels: proactive and reactive strategies

    International Nuclear Information System (INIS)

    Claudi, R.

    1998-01-01

    Most plant people would agree that having zebra mussels in any raw water system is not desirable. System blockage, loss of heat transfer and other associated safety hazards are not pleasant to deal with. Therefore most industries strive to minimise the effect of infestation. Opinions differ as to how to do this most efficiently and economically. Some facilities are committed to preventing the settlement of veligers in their piping systems and on some of the external structures they consider critical. This is the proactive approach. Others allow settlement and only treat the system or surface after fouling has occurred. This is the reactive approach. Which is the best and most economical treatment will depend on the individual facility and sometimes on the individual system. The paper examines the different proactive and reactive strategies available to-date and how they are being used. It will also discuss some of the criteria for choosing a proactive vs. reactive approach and why the decision has to be made individually by each facility. (author)

  6. Prevention and control of zebra mussels: proactive and reactive strategies

    Energy Technology Data Exchange (ETDEWEB)

    Claudi, R. [Ontario Hydro Nuclear, Toronto, ON (Canada)

    1998-07-01

    Most plant people would agree that having zebra mussels in any raw water system is not desirable. System blockage, loss of heat transfer and other associated safety hazards are not pleasant to deal with. Therefore most industries strive to minimise the effect of infestation. Opinions differ as to how to do this most efficiently and economically. Some facilities are committed to preventing the settlement of veligers in their piping systems and on some of the externalstructures they consider critical. This is the proactive approach. Others allow settlement and only treat the system or surface after fouling has occurred. This is the reactive approach. Which is the best and most economical treatment will depend on the individual facility and sometimes on the individual system. The paper examines the different proactive and reactive strategies available to-date and how they are being used. It will also discuss some of the criteria for choosing a proactive vs. reactive approach and why the decision has to be made individually by each facility. (author)

  7. Assessing the potential for fish predation to impact zebra mussels (Dreissena polymorpha): Insight from bioenergetics models

    Science.gov (United States)

    Eggleton, M.A.; Miranda, L.E.; Kirk, J.P.

    2004-01-01

    Rates of annual food consumption and biomass were modeled for several fish species across representative rivers and lakes in eastern North America. Results were combined to assess the relative potential of fish predation to impact zebra mussels (Dreissena polymorpha). Predicted annual food consumption by fishes in southern waters was over 100% greater than that in northern systems because of warmer annual water temperatures and presumed increases in metabolic demand. Although generally increasing with latitude, biomasses of several key zebra mussel fish predators did not change significantly across latitudes. Biomasses of some less abundant fish predators did increase significantly with latitude, but increases were not of the magnitude to offset predicted decreases in food consumption. Our results generally support the premise that fishes in rivers and lakes of the southern United States (U.S.) have inherently greater potential to impact zebra mussels by predation. Our simulations may provide a partial explanation of why zebra mussel invasions have not been as rapid and widespread in southern U.S. waters compared to the Great Lakes region. ?? Blackwell Munksgaard, 2004.

  8. Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes.

    Science.gov (United States)

    Tang, Wen-Li; Evans, Douglas; Kraemer, Lisa; Zhong, Huan

    2017-02-01

    Understanding body size-dependent metal accumulation in aquatic organisms (i.e., metal allometry) is critical in interpreting biomonitoring data. While growth has received the most attention, little is known about controls of metal exposure routes on metal allometry. Here, size-dependent Cd accumulation in zebra mussels (Dreissena polymorpha) from different routes were investigated by exposing mussels to A.( 111 Cd spiked algae+ 113 Cd spiked river water) or B.( 111 Cd spiked sediments+ 113 Cd spiked river water). After exposure, 111 Cd or 113 Cd levels in mussel tissue were found to be negatively correlated with tissue weight, while Cd allometry coefficients (b values) were dependent on Cd exposure routes: -0.664 for algae, -0.241 for sediments and -0.379 for river water, compared to -0.582 in un-exposed mussels. By comparing different Cd exposure routes, we found that size-dependent Cd bioaccumulation from algae or river water could be more responsible for the overall size-dependent Cd accumulation in mussels, and the relative importance of the two sources was dependent on mussel size ranges: Cadmium obtained from algae (algae-Cd) was more important in size-dependent Cd accumulation in smaller mussels (tissue dry weight  5 mg). In contrast, sediment-Cd contributed only a small amount to Cd accumulation in zebra mussels and may have little effect on size-dependent Cd bioaccumulation. Our results suggest that size-dependent Cd accumulation in mussels could be largely affected by exposure routes, which should be considered when trying to interpret Cd biomonitoring data of zebra mussels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Chronological history of zebra and quagga mussels (Dreissenidae) in North America, 1988-2010

    Science.gov (United States)

    Benson, Amy J.

    2013-01-01

    An unprecedented invasion began in North America in the mid-/late-1980s when two Eurasian mussel species, Dreissena polymorpha (zebra mussel) and Dreissena rostriformis bugensis (quagga mussel), became established in Laurentian Great Lakes. It is believed that Lake Erie was the initial location of establishment for both species, and within 3 years, zebra mussels had been found in all the Great Lakes. Since 1986, the combined distribution of two dreissenids has expanded throughout the Great Lakes region and the St. Lawrence River in Canada and also in the United States from the Great Lakes to the Mississippi Basin including Arkansas, Cumberland, Illinois, Missouri, Ohio, and Tennessee river basins. The distribution of dreissenid mussels in the Atlantic drainage has been limited to the Hudson and Susquehanna rivers. In the western United States, the quagga mussel established a large population in the lower Colorado River and spread to reservoirs in Arizona, California, Colorado, Nevada, and Utah. Overall, dreissenid species have been documented in 131 river systems and 772 inland lakes, reservoirs, and impoundments in the United States.

  10. Use of alternating and pulsed direct current electrified fields for zebra mussel control

    Science.gov (United States)

    Luoma, James A.; Dean, Jan C.; Severson, Todd J.; Wise, Jeremy K.; Barbour, Matthew

    2017-01-01

    Alternatives to chemicals for controlling dreissenid mussels are desirable for environmental compatibility, but few alternatives exist. Previous studies have evaluated the use of electrified fields for stunning and/or killing planktonic life stages of dreissenid mussels, however, the available literature on the use of electrified fields to control adult dreissenid mussels is limited. We evaluated the effects of sinusoidal alternating current (AC) and 20% duty cycle square-wave pulsed direct current (PDC) exposure on the survival of adult zebra mussels at water temperatures of 10, 15, and 22 °C. Peak voltage gradients of ~ 17 and 30 Vp/cm in the AC and PDC exposures, respectively, were continuously applied for 24, 48, or 72 h. Peak power densities ranged from 77,999 to 107,199 µW/cm3 in the AC exposures and 245,320 to 313,945 µW/cm3 in the PDC exposures. The peak dose ranged from 6,739 to 27,298 Joules/cm3 and 21,306 to 80,941 Joules/cm3 in the AC and PDC exposures, respectively. The applied power ranged from 16.6 to 68.9 kWh in the AC exposures and from 22.2 to 86.4 kWh in the PDC exposures. Mortality ranged from 2.7 to 92.7% in the AC exposed groups and from 24.0 to 98.7% in PDC exposed groups. Mortality increased with corresponding increases in water temperature and exposure duration, and we observed more zebra mussel mortality in the PDC exposures. Exposures conducted with AC required less of a peak dose (Joules/cm3) but more applied power (kWh) to achieve the same level of adult zebra mussel mortality as corresponding PDC exposures. The results demonstrate that 20% duty cycle square-wave PDC requires less energy than sinusoidal AC to inducing the same level of adult zebra mussel mortality.

  11. Local monitoring program for invasion of zebra mussel (Dreissena polymorpha) in the Dam lake Zhrebchevo, Bulgaria

    OpenAIRE

    Stoyanova, Stefka; Nikolov, Galin; Velichkova, Katya; Atanasoff, Alexander; Mumun, Sevdegul

    2015-01-01

    Zebra mussels (Dreissena polymorpha) are bivalve mollusks approximately 1 to 5 cm long that live in freshwater lakes. They have invaded many Bulgarian freshwater ecosystems in recent decades. Because of their ability to settle on almost any substrate, zebra mussels cause severe damage to closed water systems, RAS and intensive fish farming systems. In order to assess the status of the mussel population in the lake in the area of the Forest group fish farm, the distribution, extent of coloniza...

  12. CRAYFISH PREDATION EXPERIMENTS ON THE INTRODUCED ZEBRA MUSSEL, DREISSENA POLYMORPHA, IN IRELAND, AND THEIR POTENTIAL FOR BIOCONTROL.

    Directory of Open Access Journals (Sweden)

    REYNOLDS J. D.

    2001-04-01

    Full Text Available The zebra mussel Dreissena polymorpha, native to the Aralo-Caspian region, has spread across Europe in the last 180 years. Although it reached England in 1820, it only arrived in Ireland in around 1995, probably attached to the hull of pleasure boats, and since then has spread through the lowland Shannon and Erne systems, which are linked by canal. While White-clawed crayfish Austropotamobius pallipes (Lereboullet occur in these systems, Dreissena has not yet colonized sites with large crayfish populations. In laboratory experiments crayfish of both sexes ranging in size from 32-48 mm carapace length (CL were offered zebra mussels in 7 size classes spanning a range from 3-17 mm total length. Crayfish fed most on small mussels, although there was some correlation between size of crayfish and largest mussels attacked. When eaten mussels were not replaced, crayfish shifted to larger sizes. In the presence of alternative prey, experienced crayfish ate mussels and alternative foods in similar amounts while those who had never encountered zebra mussels nearly always chose the alternative foods first. The possibility of crayfish exerting significant controlling impacts on expanding mussel populations is discussed.

  13. Organotins in zebra mussels (Dreissena polymorpha) and sediments of the Quebec City Harbour area of the St. Lawrence River.

    Science.gov (United States)

    Regoli, L; Chan, H M; de Lafontaine, Y; Mikaelian, I

    2001-07-01

    Toxic antifouling agents such as tributyltin (TBT) and triphenyltin (TPT) have been released in aquatic ecosystems through the use of antifouling paint applied to ship hulls, pleasure crafts and fish nets and these compounds can bioaccumulate in aquatic organisms. The purpose of this study was 1) to assess the extent of the distribution of organotins from a contaminated marina to the St. Lawrence River system by measuring organotin concentrations in zebra mussels (Dreissena polymorpha) and in sediments collected from 9 sites along the St. Lawrence River near Quebec City in July 1998, and 2) to examine the histopathological condition of zebra mussel tissues from these sites. TBT concentrations in zebra mussels were between 37 and 1078 ng Sn g(-1) wet weight, with the highest value found in the Bassin Louise marina. Elevated concentrations were also found in two other marinas. The concentrations decreased sharply to background levels just outside the marinas. All butyltins were detected in all sediments analysed, with highest values found in the Bassin Louise marina. Phenyltins were detected in three of the nine sites in low concentrations (zebra mussels. There was a significant correlation between TBT in sediments and mussels. Gonadal development of zebra mussels varied largely between sites, and was negatively associated to TBT levels in mussel tissue. This study shows that TBT contamination remains a problem in localised freshwater sectors of the St. Lawrence River.

  14. Modeling the Role of Zebra Mussels in the Proliferation of Blue-green Algae in Saginaw Bay, Lake Huron

    Science.gov (United States)

    Under model assumptions from Saginaw Bay 1991, selective rejection of blue-green algae by zebra mussels appears to be a necessary factor in the enhancement of blue-green algae production in the presence of zebra mussels. Enhancement also appears to depend on the increased sedime...

  15. IMPACT OF OXYGEN CONCENTRATION ON ZEBRA MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2003-01-27

    These tests have indicated that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels in environments having dissolved oxygen (DO) concentrations ranging from very low to very high. The results suggest that the highest mussel kill can be achieved in moderately to highly aerated environments, while kill may be 0-20% lower under conditions of very low oxygen. For example, under highly oxygenated conditions 97% kill was achieved while conditions having low DO produced 79% mussel kill. Service water measured in a local power plant indicated that DO concentrations were in the range of 8-9 ppm (e.g., highly aerated) within their pipes. Therefore, we will not expect to see decreases in the efficacy of CL0145A treatments due to oxygen levels within such power plant pipes.

  16. IMPACT OF OXYGEN CONCENTRATION ON ZEBRA MUSSEL MORTALITY

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2003-01-01

    These tests have indicated that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels in environments having dissolved oxygen (DO) concentrations ranging from very low to very high. The results suggest that the highest mussel kill can be achieved in moderately to highly aerated environments, while kill may be 0-20% lower under conditions of very low oxygen. For example, under highly oxygenated conditions 97% kill was achieved while conditions having low DO produced 79% mussel kill. Service water measured in a local power plant indicated that DO concentrations were in the range of 8-9 ppm (e.g., highly aerated) within their pipes. Therefore, we will not expect to see decreases in the efficacy of CL0145A treatments due to oxygen levels within such power plant pipes

  17. The Influence of the Zebra Mussel (Dreisena Polymorhpa) on Magnesium and Calcium Concentration in Water

    OpenAIRE

    Wojtal-Frankiewicz Adrianna; Frankiewicz Piotr

    2011-01-01

    In this study we examined changes in magnesium and calcium ion concentrations depending on Zebra Mussel biomass, pH values and temperature. We performed field experiments in years with different weather conditions using twelve 200 litre polycarbonate containers filled with 150 litres of non-filtered water from lowland, eutrophic reservoirs. Three treatments of the experiment were represented by: Phyto control with non-filtered water, Phyto+Dreis A with Zebra Mussel biomass of 500 g/m2, and Ph...

  18. The use of food grade oil in the prevention of vase tunicate fouling on mussel aquaculture gear

    Directory of Open Access Journals (Sweden)

    Jiselle A. BAKKER

    2011-01-01

    Full Text Available Current mitigation strategies against invasive tunicates on mussel aquaculture gear in Prince Edward Island concentrate on labour-intensive and costly fouling removal. Instead of removal, this study focused on preventing the settlement of the vase tunicate Ciona intestinalis and other fouling organisms by applying a layer of food grade oil to gear prior to recruitment. Laboratory tests established the adherence and persistence of shortening, a food grade oil with a melting point exceeding ambient water temperatures, to rope and mussels. In situ tests showed that shortening decreased C. intestinalis weight and abundance on buoys, spat collector ropes and collector plates but not on mussel socks. Fouling by algae and other tunicates was significantly reduced on most substrates. There were no detrimental effects of shortening treatment on mussel length and abundance on mussel socks, but total mussel weight was significantly lower on shortening-treated socks. Shortening treatment did not significantly affect mussel spat settlement on spat collector ropes, but further evaluation is required. Overall, shortening application has considerable potential for reducing tunicate and other fouling, particularly on buoys.

  19. Selective grazing by adults and larvae of the zebra mussel (Dreissena polymorpha): application of flow cytometry to natural seston

    NARCIS (Netherlands)

    Dionisio Pires, L.M.; Jonker, R.R.; Donk, E.van; Laanbroek, H.J.

    2004-01-01

    1. Selective grazing of adults and larvae of the zebra mussel (Dreissena polymorpha) on phytoplankton and detritus from both laboratory cultures and natural seston was quantified using flow cytometry. 2. Mean clearance rate of adult zebra mussels was higher on a mixture of the green

  20. LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2001-01-01

    These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present

  1. LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2001-10-28

    These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present.

  2. Selective grazing by adults and larvae of the zebra mussel (Dreissena polymorpha): application of flow cytometry to natural seston

    NARCIS (Netherlands)

    Pires, L.M.D.; Jonker, R.M.; Van Donk, E.; Laanbroek, H.J.

    2004-01-01

    1. Selective grazing of adults and larvae of the zebra mussel (Dreissena polymorpha) on phytoplankton and detritus from both laboratory cultures and natural seston was quantified using flow cytometry. 2. Mean clearance rate of adult zebra mussels was higher on a mixture of the green alga Scenedesmus

  3. Temporal and spatial variation in Hg accumulation in zebra mussels (Dreissena polymorpha): possible influences of DOC and diet.

    Science.gov (United States)

    Kraemer, Lisa D; Evans, Douglas; Dillon, Peter J

    2013-05-01

    Zebra mussels (Dreissena polymorpha) are filter feeders located near the base of the foodweb and these animals are able to utilize a variety of carbon sources that may also vary seasonally. We conducted both a spatial and a temporal study in order to test the hypotheses: (1) dissolved organic carbon (DOC) concentrations influence Hg accumulation in zebra mussels sampled from a series of lakes and (2) seasonal variations in diet influence Hg accumulation. In the spatial study, we found a significant negative relationship between Hg concentrations and DOC concentrations, suggesting an influence of DOC on Hg bioaccumulation. In the temporal study, we used stable isotope ratios of nitrogen (δ(15)N) and carbon (δ(13)C) as ecological tools to provide a temporally integrated description of the feeding ecology of zebra mussels. Both δ(15)N and δ(13)C varied seasonally in a similar manner: more depleted values occurred in the summer and more enriched values occurred in the fall. Mercury concentrations also varied significantly over the year, with highest concentrations occurring in the summer, followed by a progressive decrease in concentrations into the fall. The C/N ratio of zebra mussels also varied significantly over the year with the lowest values occurring mid-summer and then values increased in the fall and winter, suggesting that there was significant variation in lipid stores. These results indicate that in addition to any effect of seasonal dietary changes, seasonal variation in energy stores also appeared to be related to Hg levels in the zebra mussels. Collectively results from this study suggest that DOC concentrations, seasonal variation in diet and seasonal depletion of energy stores are all important variables to consider when understanding Hg accumulation in zebra mussels. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Involvement of apoptosis in host-parasite interactions in the zebra mussel.

    Directory of Open Access Journals (Sweden)

    Laëtitia Minguez

    Full Text Available The question of whether cell death by apoptosis plays a biological function during infection is key to understanding host-parasite interactions. We investigated the involvement of apoptosis in several host-parasite systems, using zebra mussels Dreissena polymorpha as test organisms and their micro- and macroparasites. As a stress response associated with parasitism, heat shock proteins (Hsp can be induced. In this protein family, Hsp70 are known to be apoptosis inhibitors. Mussels were diagnosed for their respective infections by standard histological methods; apoptosis was detected using the TUNEL methods on paraffin sections and Hsp70 by immunohistochemistry on cryosections. Circulating hemocytes were the main cells observed in apoptosis whereas infected tissues displayed no or few apoptotic cells. Parasitism by intracellular bacteria Rickettsiales-like and the trematode Bucephalus polymorphus were associated with the inhibition of apoptosis whereas ciliates Ophryoglena spp. or the trematode Phyllodistomum folium did not involve significant differences in apoptosis. Even if some parasites were able to modulate apoptosis in zebra mussels, we did not see evidence of any involvement of Hsp70 on this mechanism.

  5. Involvement of Apoptosis in Host-Parasite Interactions in the Zebra Mussel

    Science.gov (United States)

    Minguez, Laëtitia; Brulé, Nelly; Sohm, Bénédicte; Devin, Simon; Giambérini, Laure

    2013-01-01

    The question of whether cell death by apoptosis plays a biological function during infection is key to understanding host-parasite interactions. We investigated the involvement of apoptosis in several host-parasite systems, using zebra mussels Dreissena polymorpha as test organisms and their micro- and macroparasites. As a stress response associated with parasitism, heat shock proteins (Hsp) can be induced. In this protein family, Hsp70 are known to be apoptosis inhibitors. Mussels were diagnosed for their respective infections by standard histological methods; apoptosis was detected using the TUNEL methods on paraffin sections and Hsp70 by immunohistochemistry on cryosections. Circulating hemocytes were the main cells observed in apoptosis whereas infected tissues displayed no or few apoptotic cells. Parasitism by intracellular bacteria Rickettsiales-like and the trematode Bucephalus polymorphus were associated with the inhibition of apoptosis whereas ciliates Ophryoglena spp. or the trematode Phyllodistomum folium did not involve significant differences in apoptosis. Even if some parasites were able to modulate apoptosis in zebra mussels, we did not see evidence of any involvement of Hsp70 on this mechanism. PMID:23785455

  6. Great Lakes clams find refuge from zebra mussels in restored, lake-connected marsh (Ohio)

    Science.gov (United States)

    Nichols, S. Jerrine; Wilcox, Douglas A.

    2004-01-01

    Since the early 1990s, more than 95 percent of the freshwater clams once found in Lake Erie have died due to the exotic zebara mussel (Dreissena polymorpha). Zebra mussels attach themselves to native clams in large numbers, impeding the ability of the clams to eat and burrow. However, in 1996, we discovered a population of native clams in Metzger Marsh in western Lake Erie (about 50 miles [80 km] east of Toledo) that were thriving despite the longtime presence of zebra mussel in surrounding waters. At that time, Metzger Marsh was undergoing extensive restoration, including construction of a dike to replace the eroded barrier beach and of a water-control structure to maintain hydrologic connections with the lake (Wilcox and Whillans 1999). The restoration plan called for a drawdown of water levels to promote plant growth from the seedbank -- a process that would also destroy most of the clam population. State and federal resource managers recommended removing as many clams as possible to a site that was isolated from zebra mussels, and then returning them to the marsh after it was restored. We removed about 7,000 native clams in 1996 and moved them back to Metzger Marsh in 1999.

  7. Transplanted zebra mussels (Dreissena polymorpha) as active biomonitors in an effluent-dominated river.

    Science.gov (United States)

    Smolders, Roel; Bervoets, Lieven; Blust, Ronny

    2002-09-01

    For over 20 years, mussels have been recommended as one of the most suitable biomonitoring organisms for aquatic ecosystems. Though the common mussel (Mytilus edulis) is frequently used for biomonitoring estuarine and marine ecosystems, no freshwater species is promoted for similar monitoring networks. Recently, however, the zebra mussel (Dreissena polymorpha) has been proposed as a suitable monitoring organism in freshwater ecosystems. The aim of this study was to explore the usefulness of transplanted zebra mussels as active biomonitors in an effluent-dominated stream. Results showed that for these purposes, an exposure period of at least a few weeks is required to detect any significant changes in condition status or scope for growth. Wet-tissue-weight:dry-tissue-weight ratio was the most sensitive measure to quantify effects of field exposure on physiological fitness. In case of scope for growth (SfG), energy intake was the factor determining the overall energy budget of the mussels. Based on the dilution rates of the two different effluents present, effluent 2 had the most important effect on the condition status of the exposed organisms. Overall, we conclude that the use of transplanted mussels is a sensitive and easily applicable active biomonitor that can be used to assess water quality, pollution, and subsequent recovery through self-purification in field situations.

  8. A food web modeling analysis of a Midwestern, USA eutrophic lake dominated by non-native Common Carp and Zebra Mussels

    Science.gov (United States)

    Colvin, Michael E.; Pierce, Clay; Stewart, Timothy W.

    2015-01-01

    Food web modeling is recognized as fundamental to understanding the complexities of aquatic systems. Ecopath is the most common mass-balance model used to represent food webs and quantify trophic interactions among groups. We constructed annual Ecopath models for four consecutive years during the first half-decade of a zebra mussel invasion in shallow, eutrophic Clear Lake, Iowa, USA, to evaluate changes in relative biomass and total system consumption among food web groups, evaluate food web impacts of non-native common carp and zebra mussels on food web groups, and to interpret food web impacts in light of on-going lake restoration. Total living biomass increased each year of the study; the majority of the increase due to a doubling in planktonic blue green algae, but several other taxa also increased including a more than two-order of magnitude increase in zebra mussels. Common carp accounted for the largest percentage of total fish biomass throughout the study even with on-going harvest. Chironomids, common carp, and zebra mussels were the top-three ranking consumer groups. Non-native common carp and zebra mussels accounted for an average of 42% of the total system consumption. Despite the relatively high biomass densities of common carp and zebra mussel, food web impacts was minimal due to excessive benthic and primary production in this eutrophic system. Consumption occurring via benthic pathways dominated system consumption in Clear Lake throughout our study, supporting the argument that benthic food webs are significant in shallow, eutrophic lake ecosystems and must be considered if ecosystem-level understanding is to be obtained.

  9. Making the Best of a Pest: The Potential for Using Invasive Zebra Mussel ( Dreissena Polymorpha) Biomass as a Supplement to Commercial Chicken Feed

    Science.gov (United States)

    McLaughlan, Claire; Rose, Paul; Aldridge, David C.

    2014-11-01

    Invasive non-native species frequently occur in very high densities. When such invaders present an economic or ecological nuisance, this biomass is typically removed and landfill is the most common destination, which is undesirable from both an economic and ecological perspective. The zebra mussel, Dreissena polymorpha, has invaded large parts of Europe and North America, and is routinely removed from raw water systems where it creates a biofouling nuisance. We investigated the suitability of dried, whole zebra mussels as a supplement to poultry feed, thus providing a more attractive end-use than disposal to landfill. Measurable outcomes were nutrient and energy composition analyses of the feeds and production parameters of the birds over a 14 day period. Zebra mussels were a palatable feed supplement for chickens. The mussel meal contained high levels of calcium (344.9 g kg-1), essential for egg shell formation, which was absorbed and retained easily by the birds. Compared with standard feed, a mussel-supplemented diet caused no significant effects on production parameters such as egg weight and feed conversion ratio during the study period. However, protein and energy levels in the zebra mussel feed were much lower than expected from the literature. In order for zebra mussels to be a viable long-term feed supplement for poultry, flesh would need to be separated from the shells in an economically viable way. If zebra mussels were to be used with the shells remaining, it seems that the resultant mussel meal would be more suitable as a calcium supplement.

  10. Human waterborne parasites in zebra mussels ( Dreissena polymorpha) from the Shannon River drainage area, Ireland.

    Science.gov (United States)

    Graczyk, Thaddeus K; Conn, David Bruce; Lucy, Frances; Minchin, Dan; Tamang, Leena; Moura, Lacy N S; DaSilva, Alexandre J

    2004-08-01

    Zebra mussels ( Dreissena polymorpha) from throughout the Shannon River drainage area in Ireland were tested for the anthropozoonotic waterborne parasites Cryptosporidium parvum, Giardia lamblia, Encephalitozoon intestinalis, E. hellem, and Enterocytozoon bieneusi, by the multiplexed combined direct immunofluorescent antibody and fluorescent in situ hybridization method, and PCR. Parasite transmission stages were found at 75% of sites, with the highest mean concentration of 16, nine, and eight C. parvum oocysts, G. lamblia cysts, and Encephalitozoon intestinalis spores/mussel, respectively. On average eight Enterocytozoon bieneusi spores/mussel were recovered at any selected site. Approximately 80% of all parasites were viable and thus capable of initiating human infection. The Shannon River is polluted with serious emerging human waterborne pathogens including C. parvum, against which no therapy exists. Zebra mussels can recover and concentrate environmentally derived pathogens and can be used for the sanitary assessment of water quality.

  11. Comparison of accumulation of micropollutants between igenous and transplanted zebra mussels (Dreissena polymorpha).

    Science.gov (United States)

    Bervoets, Lieven; Voets, Judith; Chu, Shaogang; Covaci, Adrian; Schepens, Paul; Blust, Ronny

    2004-08-01

    Zebra mussels (Dreissena polymorpha) were exposed at 12 canals and lakes situated in Flanders (Belgium), in cages for six weeks during the summer of 2002. Accumulation of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene, and trace metals were measured in the transplanted mussels and levels compared to levels in indigenous mussels. Additionally, zebra mussels were exposed at a small lake in the vicinity of Antwerp (Belgium), and accumulation of contaminants was followed for an extended period from December 2001 to April 2002. Analysis of the pollutants in the indigenous mussels showed that the selected sites displayed a wide range of pollution from near to background to very high levels of metals and/or organic contaminants when compared to the literature. For organic contaminants and for most metals, comparison of levels between caged and resident mussels revealed no significant differences. Only for cadmium and nickel, significant differences were observed, with levels being either higher (cadmium) or lower (nickel) in caged mussels. For organic contaminants, significant correlations between levels in caged and resident mussels were found with r2 values up to 0.98. For some metals, no or poor correlations were found. At most sites, concentrations of those metals were of the same order of magnitude and comparable to levels in mussels from unpolluted sites. This might explain the absence of significant correlations. When mussels were exposed for an extended period, the concentration of some pollutants increased, whereas others decreased with time. Only in the case of certain metals did levels differ significantly because of the slow depuration of metals already present in the transplanted mussels. This is an additional indication that measured concentrations in transplanted mussels indeed reflected the local situation. With this study, we were able to prove the applicability of transplanted mussels as a biomonitoring tool

  12. Efficacy of Pseudomonas fluorescens (Pf-CL145A) spray dried powder for controlling zebra mussels adhering to test substrates

    Science.gov (United States)

    Luoma, James A.; Severson, Todd J.; Weber, Kerry L.; Mayer, Denise A.

    2015-01-01

    A mobile bioassay trailer was used to assess the efficacy of Pseudomonas fluorescens (Pf-CL145A) spray dried powder (SDP) formulation for controlling zebra mussels (Dreissena polymorpha) from two midwestern lakes: Lake Carlos (Alexandria, Minnesota) and Shawano Lake (Shawano, Wisconsin). The effects of SDP exposure concentration and exposure duration on zebra mussel survival were evaluated along with the evaluation of a benthic injection application technique to reduce the amount of SDP required to induce zebra mortality.

  13. Pseudodiarrhoea in zebra mussels Dreissena polymorpha (Pallas) exposed to microcystins.

    Science.gov (United States)

    Juhel, Guillaume; Davenport, John; O'Halloran, John; Culloty, Sarah; Ramsay, Ruth; James, Kevin; Furey, Ambrose; Allis, Orla

    2006-03-01

    Microcystins are produced by bloom-forming cyanobacteria and pose significant health and ecological problems. In this study we show that zebra mussels respond differently to different strains of Microcystis aeruginosa, and that a highly toxic strain causes zebra mussels to produce large quantities of mucous pseudofaeces, 'pseudodiarrhoea', that are periodically expelled hydraulically through the pedal gape by shell valve adductions rather than by the normal ciliary tracts. Analysis of the pseudofaecal ejecta showed that the proportion of Microcystis aeruginosa relative to Asterionella formosa was high in the pseudofaeces and even higher in the 'pseudodiarrhoea' when a mixed diet was given to the mussels. This confirms that very toxic Microcystis aeruginosa were preferentially being rejected by comparison with the non-toxic diatom in the pseudofaeces and even more so in the 'pseudodiarrhoea'. Such selective rejection was not observed with low or non-toxic strains and would therefore tend to enhance the presence of toxic Microcystis aeruginosa in mixed Microcystis aeruginosa cyanobacterial blooms, as well as transferring toxins from the water column to the benthos. The observed acute irritant response to the toxin represents the first demonstration of an adverse sublethal effect of microcystins on invertebrate ecophysiology. Our results also suggest that it could be a specific response to microcystin-LF, a little studied toxin variant.

  14. Differences in metal sequestration between zebra mussels from clean and polluted field locations.

    Science.gov (United States)

    Voets, Judith; Redeker, Erik Steen; Blust, Ronny; Bervoets, Lieven

    2009-06-04

    Organisms are able to detoxify accumulated metals by, e.g. binding them to metallothionein (MT) and/or sequestering them in metal-rich granules (MRG). The different factors involved in determining the capacity or efficiency with which metals are detoxified are not yet known. In this work we studied how the sub-cellular distribution pattern of cadmium, copper and zinc in whole tissue of zebra mussels from clean and polluted surface waters is influenced by the total accumulated metal concentration and by its physiological condition. Additionally we measured the metallothionein concentration in the mussel tissue. Metal concentration increased gradually in the metal-sensitive and detoxified sub-cellular fractions with increasing whole tissue concentrations. However, metal concentrations in the sensitive fractions did not increase to the same extent as metal concentrations in whole tissues. In more polluted mussels the contribution of MRG and MT became more important. Nevertheless, metal detoxification was not sufficient to prevent metal binding to heat-sensitive low molecular weight proteins (HDP fraction). Finally we found an indication that metal detoxification was influenced by the condition of the zebra mussels. MT content could be explained for up to 83% by variations in Zn concentration and physiological condition of the mussels.

  15. Differences in metal sequestration between zebra mussels from clean and polluted field locations

    International Nuclear Information System (INIS)

    Voets, Judith; Redeker, Erik Steen; Blust, Ronny; Bervoets, Lieven

    2009-01-01

    Organisms are able to detoxify accumulated metals by, e.g. binding them to metallothionein (MT) and/or sequestering them in metal-rich granules (MRG). The different factors involved in determining the capacity or efficiency with which metals are detoxified are not yet known. In this work we studied how the sub-cellular distribution pattern of cadmium, copper and zinc in whole tissue of zebra mussels from clean and polluted surface waters is influenced by the total accumulated metal concentration and by its physiological condition. Additionally we measured the metallothionein concentration in the mussel tissue. Metal concentration increased gradually in the metal-sensitive and detoxified sub-cellular fractions with increasing whole tissue concentrations. However, metal concentrations in the sensitive fractions did not increase to the same extent as metal concentrations in whole tissues. In more polluted mussels the contribution of MRG and MT became more important. Nevertheless, metal detoxification was not sufficient to prevent metal binding to heat-sensitive low molecular weight proteins (HDP fraction). Finally we found an indication that metal detoxification was influenced by the condition of the zebra mussels. MT content could be explained for up to 83% by variations in Zn concentration and physiological condition of the mussels.

  16. Differences in metal sequestration between zebra mussels from clean and polluted field locations

    Energy Technology Data Exchange (ETDEWEB)

    Voets, Judith [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Redeker, Erik Steen [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Institute for Materials Research, Chemistry Division, Hasselt University, Agoralaan Building D G1-36, B 3590 Diepenbeek (Belgium); Blust, Ronny [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Bervoets, Lieven, E-mail: Lieven.bervoets@ua.ac.be [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2009-06-04

    Organisms are able to detoxify accumulated metals by, e.g. binding them to metallothionein (MT) and/or sequestering them in metal-rich granules (MRG). The different factors involved in determining the capacity or efficiency with which metals are detoxified are not yet known. In this work we studied how the sub-cellular distribution pattern of cadmium, copper and zinc in whole tissue of zebra mussels from clean and polluted surface waters is influenced by the total accumulated metal concentration and by its physiological condition. Additionally we measured the metallothionein concentration in the mussel tissue. Metal concentration increased gradually in the metal-sensitive and detoxified sub-cellular fractions with increasing whole tissue concentrations. However, metal concentrations in the sensitive fractions did not increase to the same extent as metal concentrations in whole tissues. In more polluted mussels the contribution of MRG and MT became more important. Nevertheless, metal detoxification was not sufficient to prevent metal binding to heat-sensitive low molecular weight proteins (HDP fraction). Finally we found an indication that metal detoxification was influenced by the condition of the zebra mussels. MT content could be explained for up to 83% by variations in Zn concentration and physiological condition of the mussels.

  17. Effects of suspended sediments on food uptake for zebra mussels in Lake Markermeer, The Netherlands

    NARCIS (Netherlands)

    Penning, W.E.; Pozzato, L.; Vijverberg, T.; Noordhuis, R.; bij de Vaate, A.; Van Donk, E.; Dionisio Pires, L.M.

    2013-01-01

    Until 1992, zebra mussels (Dreissena polymorpha) were an important food source for diving ducks in Lake Markermeer (The Netherlands). After 1993, the mussel biomass sharply declined, and the current population is in poor condition (maximum shell length <15 mm) compared to populations from adjacent

  18. Application of NMR-based metabolomics for environmental assessment in the Great Lakes using zebra mussel (Dreissena polymorpha).

    Science.gov (United States)

    Watanabe, Miki; Meyer, Kathryn A; Jackson, Tyler M; Schock, Tracey B; Johnson, W Edward; Bearden, Daniel W

    Zebra mussel, Dreissena polymorpha , in the Great Lakes is being monitored as a bio-indicator organism for environmental health effects by the National Oceanic and Atmospheric Administration's Mussel Watch program. In order to monitor the environmental effects of industrial pollution on the ecosystem, invasive zebra mussels were collected from four stations-three inner harbor sites (LMMB4, LMMB1, and LMMB) in Milwaukee Estuary, and one reference site (LMMB5) in Lake Michigan, Wisconsin. Nuclear magnetic resonance (NMR)-based metabolomics was used to evaluate the metabolic profiles of the mussels from these four sites. The objective was to observe whether there were differences in metabolite profiles between impacted sites and the reference site; and if there were metabolic profile differences among the impacted sites. Principal component analyses indicated there was no significant difference between two impacted sites: north Milwaukee harbor (LMMB and LMMB4) and the LMMB5 reference site. However, significant metabolic differences were observed between the impacted site on the south Milwaukee harbor (LMMB1) and the LMMB5 reference site, a finding that correlates with preliminary sediment toxicity results. A total of 26 altered metabolites (including two unidentified peaks) were successfully identified in a comparison of zebra mussels from the LMMB1 site and LMMB5 reference site. The application of both uni- and multivariate analysis not only confirmed the variability of altered metabolites but also ensured that these metabolites were identified via unbiased analysis. This study has demonstrated the feasibility of the NMR-based metabolomics approach to assess whole-body metabolomics of zebra mussels to study the physiological impact of toxicant exposure at field sites.

  19. Is there a link between shell morphology and parasites of zebra mussels?

    Science.gov (United States)

    Minguez, Laëtitia; Lang, Anne-Sophie; Beisel, Jean-Nicolas; Giambérini, Laure

    2012-02-01

    The shell morphology of zebra mussels, Dreissena polymorpha, was analyzed to determine if alterations in shell shape and asymmetry between valves were related to its infection status, i.e. infected or not by microparasites like ciliates Ophryoglena spp. or intracellular bacteria Rickettsiales-like organisms (RLOs), and by macroparasites like trematodes Phyllodistomum folium and Bucephalus polymorphus. For microparasites, two groups of mussels were observed depending on shell measurements. Mussels with the more concave shells were the most parasitized by ciliates. This could be more a consequence than a cause and we hypothesized that a modification of the water flow through the mantle cavity could promote the infection with a ciliate. There were more RLOs present in the most symmetrical individuals. A potential explanation involved a canalization of the left-right asymmetry as a by-product of the parasite infection. Trematode infections were associated with different responses in valve width. Females infected by P. folium displayed significantly higher symmetry in valve width compared with non-infected congeners, whereas the infection involved an opposite pattern in males. B. polymorphus was also linked to a decrease in valve width asymmetry. This study suggested that a relationship exists between parasitism and shell morphology through the physiological condition of host zebra mussels. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Habitat shift in invading species: Zebra and quagga mussel population characteristics on shallow soft substrates

    Science.gov (United States)

    Berkman, P.A.; Garton, D.W.; Haltuch, M.A.; Kennedy, G.W.; Febo, L.R.

    2000-01-01

    Unexpected habitat innovations among invading species are illustrated by the expansion of dreissenid mussels across sedimentary environments in shallow water unlike the hard substrates where they are conventionally known. In this note, records of population characteristics of invading zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels from 1994 through 1998 are reported from shallow (less than 20 m) sedimentary habitats in western Lake Erie. Haphazard SCUBA collections of these invading species indicated that combined densities of zebra and quagga mussels ranged from 0 to 32,500 individuals per square meter between 1994 and 1998, with D. polymorpha comprising 75-100% of the assemblages. These mixed mussel populations, which were attached by byssal threads to each other and underlying sand-grain sediments, had size-frequency distributions that were typical of colonizing populations on hard substrates. Moreover, the presence of two mussel cohorts within the 1994 samples indicated that these species began expanding onto soft substrates not later than 1992, within 4 years of their initial invasion in western Lake Erie. Such historical data provide baselines for interpreting adaptive innovations, ecological interactions and habitat shifts among the two invading dreissenid mussel species in North America.

  1. Book review: Biology and management of invasive quagga and zebra mussels in the western United States

    Science.gov (United States)

    Benson, Amy J.

    2017-01-01

    Water is a precious and limited commodity in the western United States and its conveyance is extremely important. Therefore, it is critical to do as much as possible to prevent the spread of two species of dreissenid mussels, both non-native and highly invasive aquatic species already well-established in the eastern half of the United States. This book addresses the occurrences of the two dreissenid mussels in the West, the quagga mussel and the zebra mussel, that are both known to negatively impact water delivery systems and natural ecosystems. It is edited by two researchers whom have extensive experience working with the mussels in the West and is composed of 34 chapters, or articles, written by a variety of experts.Book information: Biology and Management of Invasive Quagga and Zebra Mussels in the Western United States. Edited by Wai Hing Wong and Shawn L. Gerstenberger. Boca Raton (Florida): CRC Press (Taylor & Francis Group). $149.95. xx + 545 p.; ill.; index. ISBN: 978-1-4665-9561-3. [Compact Disc included.] 2015.

  2. Grazing on colonial and filamentous, toxic and non-toxic cyanobacteria by the zebra mussel Dreissena polymorpha

    NARCIS (Netherlands)

    Pires, L.M.D.; Bontes, B.M.; Van Donk, E.; Ibelings, B.W.

    2005-01-01

    Colony forming and toxic cyanobacteria form a problem in surface waters of shallow lakes, both for recreation and wildlife. Zebra mussels, Dreissena polymorpha, have been employed to help to restore shallow lakes in the Netherlands, dominated by cyanobacteria, to their former clear state. Zebra

  3. Bioavailability of particulate metal to zebra mussels: Biodynamic modelling shows that assimilation efficiencies are site-specific

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeault, Adeline, E-mail: bourgeault@ensil.unilim.fr [Cemagref, Unite de Recherche Hydrosystemes et Bioprocedes, 1 rue Pierre-Gilles de Gennes, 92761 Antony (France); FIRE, FR-3020, 4 place Jussieu, 75005 Paris (France); Gourlay-France, Catherine, E-mail: catherine.gourlay@cemagref.fr [Cemagref, Unite de Recherche Hydrosystemes et Bioprocedes, 1 rue Pierre-Gilles de Gennes, 92761 Antony (France); FIRE, FR-3020, 4 place Jussieu, 75005 Paris (France); Priadi, Cindy, E-mail: cindy.priadi@eng.ui.ac.id [LSCE/IPSL CEA-CNRS-UVSQ, Avenue de la Terrasse, 91198 Gif-sur-Yvette (France); Ayrault, Sophie, E-mail: Sophie.Ayrault@lsce.ipsl.fr [LSCE/IPSL CEA-CNRS-UVSQ, Avenue de la Terrasse, 91198 Gif-sur-Yvette (France); Tusseau-Vuillemin, Marie-Helene, E-mail: Marie-helene.tusseau@ifremer.fr [IFREMER Technopolis 40, 155 rue Jean-Jacques Rousseau, 92138 Issy-Les-Moulineaux (France)

    2011-12-15

    This study investigates the ability of the biodynamic model to predict the trophic bioaccumulation of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) in a freshwater bivalve. Zebra mussels were transplanted to three sites along the Seine River (France) and collected monthly for 11 months. Measurements of the metal body burdens in mussels were compared with the predictions from the biodynamic model. The exchangeable fraction of metal particles did not account for the bioavailability of particulate metals, since it did not capture the differences between sites. The assimilation efficiency (AE) parameter is necessary to take into account biotic factors influencing particulate metal bioavailability. The biodynamic model, applied with AEs from the literature, overestimated the measured concentrations in zebra mussels, the extent of overestimation being site-specific. Therefore, an original methodology was proposed for in situ AE measurements for each site and metal. - Highlights: > Exchangeable fraction of metal particles did not account for the bioavailability of particulate metals. > Need for site-specific biodynamic parameters. > Field-determined AE provide a good fit between the biodynamic model predictions and bioaccumulation measurements. - The interpretation of metal bioaccumulation in transplanted zebra mussels with biodynamic modelling highlights the need for site-specific assimilation efficiencies of particulate metals.

  4. Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

    Science.gov (United States)

    Kobak, Jarosław; Poznańska, Małgorzata; Jermacz, Łukasz; Kakareko, Tomasz; Prądzynski, Daniel; Łodygowska, Małgorzata; Montowska, Karolina; Bącela-Spychalska, Karolina

    2016-01-01

    Aggregations of the Ponto-Caspian invasive zebra mussel ( Dreissena polymorpha ) constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae) densities (from ca. 500 to 2,000 individuals m -2 ) in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG) and western tubenose goby Proterorhinus semilunaris (WTG) compared to sandy and stone substrata (containing the basic prey density of 500 ind. m -2 ). Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m -2 ), regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas, contributing to an

  5. Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

    Directory of Open Access Journals (Sweden)

    Jarosław Kobak

    2016-11-01

    Full Text Available Aggregations of the Ponto-Caspian invasive zebra mussel (Dreissena polymorpha constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae densities (from ca. 500 to 2,000 individuals m−2 in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG and western tubenose goby Proterorhinus semilunaris (WTG compared to sandy and stone substrata (containing the basic prey density of 500 ind. m−2. Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m−2, regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas

  6. Comparing a microbial biocide and chlorine as zebra mussel control strategies in an Irish drinking water treatment plant

    Directory of Open Access Journals (Sweden)

    Sara Meehan

    2013-06-01

    Full Text Available A need exists for an environmentally friendly mussel control method to replace chlorine and other traditional control methods currentlyutilised in drinking water plants and other infested facilities. Zequanox® is a newly commercialised microbial biocide for zebra and quaggamussels comprised of killed Pseudomonas fluorescens CL145A cells. The objective of this study was to compare the efficacy of adevelopmental formulation of Zequanox (referred to as MBI 401 FDP and chlorine treatments on adult and juvenile zebra mussels byrunning a biobox trial in conjunction with chlorine treatments at an infested Irish drinking water treatment plant. Since 2009, the plantmanagement has used a residual chlorine concentration of 2 mg/L in autumn to control both adult zebra mussels and juvenile settlement intheir three concrete raw water chambers. Juvenile mussel settlement was monitored in three bioboxes as well as in three treatment chambersin the plant for three months prior to treatment. Adult mussels were seeded into the chambers and bioboxes four days before treatment. InOctober 2011, the bioboxes were treated with MBI 401 FDP at 200 mg active substance/L, while chlorine treatment took place in the waterchambers. The MBI 401 FDP treatment lasted only 8 hours while chlorine treatment lasted seven days. Juvenile numbers were reduced tozero in both the bioboxes and treated chambers within seven days. Adult mussel mortality reached 80% for both the chlorine and MBI 401FDP treatment; however, mortality was achieved faster in the chlorine treatment. These results provided important insights into zebra musselcontrol alternatives to chlorine and supported further development of the now commercial product, Zequanox.

  7. Early responses to zebra mussels in the Great Lakes: a journey from information vacuum to policy and regulation

    Science.gov (United States)

    Griffiths, Ronald W.; Schloesser, Don W.; Kovalak, William P.

    2013-01-01

    Invasive species such as zebra mussels pose a threat to the economies and environments of coastal and fresh-water habitats around the world. Consequently, it is important that government policies and programs be adequate to protect these waters from invaders. This chapter documents key events that took place in the early years (1988-1991) of zebra mussel colonization of the Laurentian Great Lakes and evaluates government responses (policies and programs) to this disruptive, invasive, freshwater species.

  8. Are Predators Limiting Zebra Mussel Colonization of Unionid Mussels in Great Lake Coastal Wetlands?

    Science.gov (United States)

    de Szalay, F. A.; Bowers, R.

    2005-05-01

    Although many native mollusc populations have been eliminated in the Laurentian Great Lakes by the exotic zebra mussel, recent surveys have found abundant unionid (Bivalvia: Unionidae) populations in some coastal wetlands. Unionid burrowing in soft sediments and predation by fish have been shown to reduce numbers of attached zebra mussels, and we tested these factors in a Lake Erie coastal wetland. In 2002, we held live unionids (Leptodea fragilis, Quadrula quadrula) and Pyganodon grandis shells in exclosures with wire mesh bottoms that were buried to sediment depths of either 5, 10, or 20 cm. After 2 months, numbers of attached dreissenids on unionids were significantly higher inside all exclosure treatments than outside exclosures. This indicated that either unionid burrowing was prevented in all sediment depth treatments or molluscivores were excluded by exclosures. In 2004, we measured dreissenid colonization on Q. quadrula and PVC plates in bottomless exclosures with different mesh sizes. After 6 months, dreissenid numbers on PVC plates and on Q. quadrula in 2.5 cm X 2.5 cm and 5 cm X 10 cm mesh exclosures were significantly higher than in open exclosures. These data suggest that molluscivores are important in limiting dreissenids in Great Lake coastal wetlands.

  9. Influence of ortho-substitution homolog group on polychlorobiphenyl bioaccumulation factors and fugacity ratios in plankton and zebra mussels (Dreissena polymorpha)

    Energy Technology Data Exchange (ETDEWEB)

    Willman, E.J.; Manchester-Neesvig, J.B.; Agrell, C.; Armstrong, D.E.

    1999-07-01

    The accumulation of a set of non- and mono-ortho (coplanar) PCB congeners in aquatic ecosystems is of interest due to their dioxin-like toxicities. Chemical properties (octanol-water partition coefficients) suggest that the coplanar congeners may accumulate in organisms to a greater extent than homologs with greater ortho substitution. The authors analyzed a set of 65 PCB congeners with zero to four ortho-chlorines from seven homolog groups in water, suspended particulate matter, and zebra mussels from Green Bay, Wisconsin, USA, on four dates throughout the ice-free season. The suspended particulate matter was separated by size and characterized as phytoplankton or zooplankton using diagnostic carotenoid pigments and light microscopy. Median bioconcentration factors (BCFs) for accumulation from water by phytoplankton and bioaccumulation factors (BAFs) for accumulation from water plus food by zooplankton and zebra mussels ranged from 1 x 10{sup 4} to 1 x 10{sup 6} and were generally the greatest for the tetra- to heptachlorobiphenyls. The average coplanar congener BCFs and BAFs for accumulation from water by phytoplankton, zooplankton, and zebra mussels for the tri-, tetra-, and pentachlorobiphenyls were 54% larger than corresponding values for their homologs. Biomagnification factors (BMFs) of the tetra-, penta-, and hexachlorobiphenyls between zooplankton and zebra mussels and their food source, phytoplankton, typically ranged between 1 and 10, but the average coplanar congener BMFs were 25% less than values for their corresponding homologs. The tendency for coplanar congeners to accumulate to a lesser extent between trophic levels was not as large as their tendency to accumulate from water to a greater extent. Based on accumulation factors, the authors conclude that the dioxin-like tetra- and pentachlorobiphenyls generally accumulate in the phytoplankton, zooplankton, and zebra mussels of the Green Bay ecosystem to a greater extent than other congeners. Fugacity

  10. THE USE OF COST-TRANSFER ANALYSIS TO ESTIMATE THE ECONOMIC IMPACTS OF A POTENTIAL ZEBRA MUSSEL INFESTATION IN FLORIDA

    OpenAIRE

    Rossi, Frederick J.; Adams, Damian C.; Lee, Donna J.

    2004-01-01

    Zebra mussel (Dreissena polymorpha) colonization of the eastern United States has resulted in expenditures of tens of millions of dollars spent by consumptive surface water users, in order to mitigate infrastructure impairment caused by this invasive species. Analogous to benefit-transfer analysis, a "cost-transfer" approach will be used to obtain general estimates of potential mitigation costs of zebra mussels in an area (Florida) that this invasive species has yet to establish itself. The g...

  11. Zebra mussels mitigation at Ontario Hydro's hydroelectric generating facilities

    International Nuclear Information System (INIS)

    Dorneanu, A.M.

    1992-01-01

    The Great Lakes and their connecting channels have recently been invaded by a tiny freshwater mollusc that has already cost Ontario Hydro millions of dollars. Dreissena polymorpha, commonly known as the zebra mussel, entered the great lakes in ballast water carried by a ship from Europe in 1985. These mussels threaten to reduce or totally block the flow of water in auxiliary systems of any generating station, water treatment plant or municipal water facility that uses raw lake water and to cause accelerated corrosion of the metallic substrate to which they attach themselves. To satisfy the immediate need for control, chlorination was identified as the most effective interim measure to prevent the biofouling of the raw water systems. Detection and monitoring of mussels and the installation, operation, environmental constraints, benefits and deficiencies of the chemical treatment system are presented. Long term objectives for control of the mussels are to develop alternatives to chlorination (ozone, hydrogen peroxide, protective coatings, thermal shock, mechanical filtration, etc.) for application at existing facilities and for incorporation into the design of new facilities and rehabilitation programs. 3 refs., 5 figs

  12. Zebra mussel filter feeding and food-limited production of Daphnia: Recent changes in lower trophic level dynamics of Oneida Lake, New York, U.S.A.

    Science.gov (United States)

    Horgan, M.J.; Mills, E.L.

    1999-01-01

    Exotic zebra mussels can alter lower trophic level dynamics in lakes that they colonize by consuming large quantities of phytoplankton. We simulated the indirect effects of zebra mussel grazing on Daphnia by artificially reducing phytoplankton concentration for in situ Daphnia reproduction experiments. The response of Daphnia reproduction to reduced phytoplankton was evaluated for both the in situ experiments and field observations in Oneida Lake, New York, U.S.A. Oneida Lake has had an abundant population of zebra mussels since 1992. Our experiments revealed that fecundity of individuals from two species of Daphnia was positively related to phytoplankton concentration during the spring clearwater phase, although there was no discernible effect of food concentration on fecundity in summer cyanobacteria-dominated assemblages. The experimental results suggest that Daphnia fecundity responds to chlorophyll a concentrations zebra mussels became abundant in Oneida Lake have been characterized by high water clarity, low chlorophyll concentrations, long clearwater phases, and low Daphnia biomass compared with the previous 17 years. The food web effects of zebra mussel grazing are complex and it will take more years for impacts at higher trophic levels to develop and be identified.

  13. The zebra mussel (Dreissena polymorpha), a new pest in North America: reproductive mechanisms as possible targets of control strategies

    Science.gov (United States)

    Ram, Jeffrey L.; Fong, Peter; Croll, Roger P.; Nichols, Susan J.; Wall, Darcie

    1992-01-01

    The zebra mussel (Dreissena polymorpha) has spread rapidly in temperate fresh waters of North America since its introduction into the Great Lakes in 1985 or 1986. It attaches to hard substrates, forming layers, occluding water intakes, encrusting and killing native mussels, filtering algae in competition with other planktivores, and possibly interfering with fish spawning. It reproduces prolifically, suggesting that an approach to its control may be by controlling its reproduction. Previous literature suggests that spawning in bivalves is regulated by both environmental and internal chemical cues. A suggested sequence is that phytoplankton chemicals initially trigger spawning; chemicals associated with gametes provide a species-specific pheromonal positive feedback for spawning; and the response to environmental chemicals is mediated internally by serotonin (5-HT). The role of 5-HT in zebra mussels is under investigation. Both males and females can be induced to spawn by either injection or external application of 5-HT. The response can also be activated by 8-hydroxy-2-(di-n-propylamino)-tetralin, an agonist at 5-HT1A receptors. HPLC analysis has detected 5-HT as the major biogenic amine in both male and female gonads. 5-HT immunocytochemistry demonstrates nerves containing serotonergic fibers innervating gonads of both males and females, with prominent varicosities surrounding the follicles in both sexes. A role of 5-HT in mediating spawning responses in zebra mussels is thus strongly supported. These studies have shown that reproductive behavior of zebra mussels can be modified by outside chemicals, a property that may be exploited for purposes of control.

  14. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas. Potential use for genotoxicant biomonitoring of fresh water ecosystems.

    Science.gov (United States)

    Le Goff, J; Gallois, J; Pelhuet, L; Devier, M H; Budzinski, H; Pottier, D; André, V; Cachot, J

    2006-08-12

    The purpose of this study was to examine PAH accumulation and bulky DNA adduct formation in the digestive gland of zebra mussels exposed in their habitat or in controlled laboratory conditions to complex mixture of PAH. DNA adducts were measured using a 32P-postlabelling protocol with nuclease P1 enrichment adapted from Reddy and Randerath [Reddy, M.V., Randerath, K., 1986. Nuclease P1-mediated enhancement of sensitivity of 32P-postlabelling test for structurally diverse DNA adducts. Carcinogenesis 7, 1543-1551]. Specimens collected in the upper part of the Seine estuary were shown to accumulate higher levels of PAH (up to 1.6 microg g(-1) dry weight) in comparison to individuals from the reference site (0.053 microg g(-1) dry weight). The former exhibited elevated levels of DNA adducts (up to 4.0/10(8) nucleotides) and higher diversity of individual adducts with five distinct spots being specifically detected in individuals originating from the Seine estuary. Zebra mussels exposed for 5 days to 0.01% (v/v) of organic extract of sediment from the Seine estuary were shown to accumulate high amounts of PAH (up to 138 microg g(-1) dry weight) but exhibited relatively low levels of DNA adducts. Exposure to benzo[a]pyrene led to a dose-dependent accumulation of B[a]P (up to 7063 microg g(-1) dry weight) and a clear induction of DNA adduct formation in the digestive gland of mussels (up to 1.13/10(8) nucleotides). Comparisons with other bivalves exposed to the same model PAH, revealed similar levels of adducts and comparable adduct profiles with a main adduct spot and a second faint one. This study clearly demonstrated that zebra mussels are able to biotransform B[a]P and probably other PAH into reactive metabolites with DNA-binding activity. This work also demonstrated the applicability of the nuclease P1 enhanced 32P-postlabelling method for bulky adduct detection in the digestive gland of zebra mussels. DNA adduct measurement in zebra mussels could be a suitable

  15. IMPACT OF THE DURATION OF BACTERIAL EXPOSURE ON ZEBRA MUSSEL MORTALITY

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2002-01-01

    These tests indicated that: (1) duration of exposure to bacterial strain CL0145A of Pseudomonas fluorescens is a key variable in obtaining zebra mussel mortality; (2) that given a choice of exposure periods up to 96 hr, the longer the exposure period, the higher the mean mortality that will be achieved; (3) that the first few hours that the mussels are exposed to the bacteria are the most important in achieving kill; (4) that the mortality achieved by exposure periods ≥72 hr may be somewhat amplified by the degraded water quality conditions which can develop in recirculating water systems over such extended time periods

  16. IMPACT OF THE DURATION OF BACTERIAL EXPOSURE ON ZEBRA MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2002-01-21

    These tests indicated that: (1) duration of exposure to bacterial strain CL0145A of Pseudomonas fluorescens is a key variable in obtaining zebra mussel mortality; (2) that given a choice of exposure periods up to 96 hr, the longer the exposure period, the higher the mean mortality that will be achieved; (3) that the first few hours that the mussels are exposed to the bacteria are the most important in achieving kill; (4) that the mortality achieved by exposure periods {>=}72 hr may be somewhat amplified by the degraded water quality conditions which can develop in recirculating water systems over such extended time periods.

  17. Sympatric Dreissena species in the Meuse River : towards a dominance shift from zebra to quagga mussels

    OpenAIRE

    Marescaux, Jonathan; Boets, Pieter; Lorquet, Julien; Sablon, Rose; Van Doninck, Karine; Beisel, Jean-Nicolas

    2015-01-01

    The rapid spread of the quagga mussel, Dreissena rostriformis, in Western Europe is of particular concern since the species is known to have serious ecological and economic impacts, similar to those of the well-established zebra mussel, Dreissena polymorpha. This study aimed (1) to provide an update on the quagga mussel distribution in several Belgian inland waterways, and (2) to check if a shift in dominance between Dreissena species is occurring. Using density measurements and artificial su...

  18. Do Zebra Mussels Grow Faster on Live Unionids than on Inanimate Substrate? A Study with Field Enclosures

    Science.gov (United States)

    Hörmann, Leonhard; Maier, Gerhard

    2006-05-01

    The zebra mussel Dreissena polymorpha has invaded numerous freshwaters in Europe and North America and can foul many types of solid substrates, including unionid bivalves. In field experiments we compared growth rates of dreissenids on live specimens of the freshwater bivalve Anodonta cygnea to growth rates of dreissenids on stones. Dreissena density in the study lake was about 1000 m-2 in most places, Anodonta density approximately 1 m-2 and about 50% of the Anodonta were infested with 10-30 Dreissena . In summer/autumn small dreissenids generally grew faster on live Anodonta than on stones. Similar trends were observed for spring, but differences of growth increments between dreissenids on live Anodonta and stones were usually not significant. Dreissenids settled down or moved towards the ingestion/egestion siphons of Anodonta and ingestion siphons of dreissenids were directed towards siphons of Anodonta . These results suggest that dreissenids can use the food provided by the filter current of the large Anodonta .

  19. Lake Erie and Lake Michigan zebra mussel settlement monitoring and implications for chlorination treatment

    International Nuclear Information System (INIS)

    Demoss, D.; Mendelsberg, J.I.

    1992-01-01

    This paper reports on the 1991 zebra mussel veliger settlement monitoring program undertaken to record and evaluate zebra mussel veliger settlement in Lake Erie and Lake Michigan. Studies by Dr. Gerald Mackie of Canada in 1990 indicated veliger settlement may be occurring primarily during short time periods every season corresponding with warmer water temperatures. Veliger settlement monitoring was performed using a plexiglass sampler apparatus. The samplers were simple in design and consisted of a 20-inch-square plexiglass base panel with thirty-six 1 inch x 3 inch clear plexiglass microscope slides attached. The results of the monitoring program indicate the existence of preferential settlement periods for veligers correlating with sustained lake water temperatures above 70 degrees F. Veliger settlement concentrations in the south basin of Lake Michigan appear to be similar to those in western Lake Erie

  20. Comparative morphology of zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel sperm: Light and electron microscopy

    Science.gov (United States)

    Walker, G.K.; Black, M.G.; Edwards, C.A.

    1996-01-01

    Adult zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels were induced to release large quantities of live spermatozoa by the administration of 5-hydroxytryptamine (serotonin). Sperm were photographed alive using phase-contrast microscopy and were fixed subsequently with glutaraldehyde followed by osmium tetroxide for eventual examination by transmission or scanning electron microscopy. The sperm of both genera are of the ect-aquasperm type. Their overall dimensions and shape allow for easy discrimination at the light and scanning electron microscopy level. Transmission electron microscopy of the cells reveals a barrel-shaped nucleus in zebra mussel sperm and an elongated nucleus in quagga mussel sperm. In both species, an acrosome is cradled in a nuclear fossa. The ultrastructure of the acrosome and axial body, however, is distinctive for each species. The structures of the midpiece are shown, including a unique mitochondrial "skirt" that includes densely packed parallel cristae and extends in a narrow sheet from the mitochondria.

  1. Bioavailability of particulate metal to zebra mussels: biodynamic modelling shows that assimilation efficiencies are site-specific.

    Science.gov (United States)

    Bourgeault, Adeline; Gourlay-Francé, Catherine; Priadi, Cindy; Ayrault, Sophie; Tusseau-Vuillemin, Marie-Hélène

    2011-12-01

    This study investigates the ability of the biodynamic model to predict the trophic bioaccumulation of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) in a freshwater bivalve. Zebra mussels were transplanted to three sites along the Seine River (France) and collected monthly for 11 months. Measurements of the metal body burdens in mussels were compared with the predictions from the biodynamic model. The exchangeable fraction of metal particles did not account for the bioavailability of particulate metals, since it did not capture the differences between sites. The assimilation efficiency (AE) parameter is necessary to take into account biotic factors influencing particulate metal bioavailability. The biodynamic model, applied with AEs from the literature, overestimated the measured concentrations in zebra mussels, the extent of overestimation being site-specific. Therefore, an original methodology was proposed for in situ AE measurements for each site and metal. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Metal concentrations in zebra mussels and sediments from embayments and riverine environments of eastern Lake Erie, southern Lake Ontario, and the Niagara River.

    Science.gov (United States)

    Lowe, T P; Day, D D

    2002-10-01

    Concentrations of 14 metals were studied in the soft tissues of zebra mussels ( Dreissena polymorpha) and sediments from 16 Great Lakes embayments and riverine environments. Samples were collected in 1993 and 1994 during the early and late autumn period when the body mass of mussels is least affected by reproductive activities. There was a significant difference in geometric mean concentrations of all metals except Cu in mussels sampled from different sites, and there was a significant difference in the geometric mean concentrations of all metals but Cd, Mn, and Zn between years. The higher metal concentrations in mussels from this study were generally similar to those in mussels from contaminated European and U.S. locations, and those with lower concentrations were similar to those from uncontaminated European and U.S. locations. Geometric mean sediment concentrations of all metals differed significantly among sites. Sediment concentrations of metals from some sites were above EPA guidelines for moderately polluted harbor sediments. Sites where zebra mussels had higher concentrations of Al, Cr, and V tended to be the same sites as those where sediment concentrations of these metals were also higher. However, there was not a significant statistical relationship between concentrations of metals in zebra mussels and sediments, except for Mg.

  3. EVALUATION OF BIOTIC AND TREATMENT FACTORS RELATING TO BACTERIAL CONTROL OF ZEBRA MUSSELS

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2002-01-01

    Testing over the last quarter has indicated the following regarding control of zebra mussels with bacterium Pseudomonas fluorescens strain CL0145A: (1) the concentration of bacteria suspended in water is directly correlated with mussel kill; (2) the ratio of bacterial mass per mussel, if too low, could limit mussel kill; a treatment must be done at a high enough ratio so that mussels do not deplete all the suspended bacteria before the end of the desired exposure period; (3) bacteria appear to lose almost all their toxicity after suspension for 24 hr in highly oxygenated water; (4) in a recirculating pipe system, the same percentage mussel kill will be achieved irrespective of whether all the bacteria are applied at once or divided up and applied intermittently in smaller quantities over a 10-hr period. Since this is the fourth quarterly report, a summation of all test results over the last twelve months is provided as a table in this report. The table includes the above-mentioned fourth-quarter results

  4. EVALUATION OF BIOTIC AND TREATMENT FACTORS RELATING TO BACTERIAL CONTROL OF ZEBRA MUSSELS

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2002-04-30

    Testing over the last quarter has indicated the following regarding control of zebra mussels with bacterium Pseudomonas fluorescens strain CL0145A: (1) the concentration of bacteria suspended in water is directly correlated with mussel kill; (2) the ratio of bacterial mass per mussel, if too low, could limit mussel kill; a treatment must be done at a high enough ratio so that mussels do not deplete all the suspended bacteria before the end of the desired exposure period; (3) bacteria appear to lose almost all their toxicity after suspension for 24 hr in highly oxygenated water; (4) in a recirculating pipe system, the same percentage mussel kill will be achieved irrespective of whether all the bacteria are applied at once or divided up and applied intermittently in smaller quantities over a 10-hr period. Since this is the fourth quarterly report, a summation of all test results over the last twelve months is provided as a table in this report. The table includes the above-mentioned fourth-quarter results.

  5. Haplosporidium raabei n. sp. (Haplosporidia): a parasite of zebra mussels, Dreissena polymorpha (Pallas, 1771).

    Science.gov (United States)

    Molloy, D P; Giambérini, L; Stokes, N A; Burreson, E M; Ovcharenko, M A

    2012-04-01

    Extensive connective tissue lysis is a common outcome of haplosporidian infection. Although such infections in marine invertebrates are well documented, they are relatively rarely observed in freshwater invertebrates. Herein, we report a field study using a comprehensive series of methodologies (histology, dissection, electron microscopy, gene sequence analysis, and molecular phylogenetics) to investigate the morphology, taxonomy, systematics, geographical distribution, pathogenicity, and seasonal and annual prevalence of a haplosporidian observed in zebra mussels, Dreissena polymorpha. Based on its genetic sequence, morphology, and host, we describe Haplosporidium raabei n. sp. from D. polymorpha - the first haplosporidian species from a freshwater bivalve. Haplosporidium raabei is rare as we observed it in histological sections in only 0·7% of the zebra mussels collected from 43 water bodies across 11 European countries and in none that were collected from 10 water bodies in the United States. In contrast to its low prevalences, disease intensities were quite high with 79·5% of infections advanced to sporogenesis.

  6. Spatio-temporal spawning and larval dynamics of a zebra mussel (Dreissena polymorpha) population in a North Texas Reservoir: implications for invasions in the southern United States

    Science.gov (United States)

    Churchill, Christopher John

    2013-01-01

    Zebra mussels were first observed in Texas in 2009 in a reservoir (Lake Texoma) on the Texas-Oklahoma border. In 2012, an established population was found in a near-by reservoir, Ray Roberts Lake, and in June 2013, settled mussels were detected in a third north Texas reservoir, Lake Lewisville. An established population was detected in Belton Lake in September 2013. With the exception of Louisiana, these occurrences in Texas mark the current southern extent of the range of this species in the United States. Previous studies indicate that zebra mussel populations could be affected by environmental conditions, especially increased temperatures and extreme droughts, which are characteristic of surface waters of the southern and southwestern United States. Data collected during the first three years (2010–12) of a long-term monitoring program were analyzed to determine if spatio-temporal zebra mussel spawning and larval dynamics were related to physicochemical water properties in Lake Texoma. Reproductive output of the local population was significantly related to water temperature and lake elevation. Estimated mean date of first spawn in Lake Texoma was approximately 1.5 months earlier and peak veliger densities were observed two months earlier than in Lake Erie. Annual maximum veliger density declined significantly during the study period (p mussels in littoral zones. Veliger spatial distributions were associated with physicochemical stratification characteristics. Veligers were observed in the deepest oxygenated water after lake stratification, which occurred in late spring. Results of this study indicate environmental conditions can influence variability of population sizes and spatial distributions of zebra mussels along the current southern frontier of their geographic range. Although the future population size trajectory and geographic range are uncertain, increased temperatures and intermittent, extreme droughts likely will affect spatio-temporal dynamics of

  7. Parasitism can be a confounding factor in assessing the response of zebra mussels to water contamination

    International Nuclear Information System (INIS)

    Minguez, Laëtitia; Buronfosse, Thierry; Beisel, Jean-Nicolas; Giambérini, Laure

    2012-01-01

    Biological responses measured in aquatic organisms to monitor environmental pollution could be also affected by different biotic and abiotic factors. Among these environmental factors, parasitism has often been neglected even if infection by parasites is very frequent. In the present field investigation, the parasite infra-communities and zebra mussel biological responses were studied up- and downstream a waste water treatment plant in northeast France. In both sites, mussels were infected by ciliates and/or intracellular bacteria, but prevalence rates and infection intensities were different according to the habitat. Concerning the biological responses differences were observed related to the site quality and the infection status. Parasitism affects both systems but seemed to depend mainly on environmental conditions. The influence of parasites is not constant, but remains important to consider it as a potential confounding factor in ecotoxicological studies. This study also emphasizes the interesting use of integrative indexes to synthesize data set. Highlights: ► Study of potential bias associated with the use of infected zebra mussels in ecotoxicological studies. ► Presence of infected mussels on banks and channels, up- and downstream a waste water treatment plant. ► Parasitism influence on biological responses dependent of mussel population history. ► Integrative index, an interesting tool to synthesize the set of biological data. - Parasitism influence on the host physiology would be strongly dependent on environmental conditions but remains a potential confounding factor in ecotoxicological studies.

  8. GIS-based multi-criteria site selection for zebra mussel cultivation: Addressing end-of-pipe remediation of a eutrophic coastal lagoon ecosystem.

    Science.gov (United States)

    Bagdanavičiūtė, Ingrida; Umgiesser, Georg; Vaičiūtė, Diana; Bresciani, Mariano; Kozlov, Igor; Zaiko, Anastasija

    2018-04-11

    Farming of shellfish and seaweeds is a tested tool for mitigating eutrophication consequences in coastal environments, however as many other marine economic activities it should be a subject of marine spatial planning for designating suitable sites. The present study proposes site selection framework for provisional zebra mussel farming in a eutrophic lagoon ecosystem, aimed primarily at remediation purposes. GIS-based multi-criteria approach was applied, combining data from empirical maps, numerical models and remote sensing to estimate suitability parameters. Site selection and prioritisation of suitable areas considered 15 environmental and socio-economic criteria, which contributed to 4 optimisation models (settlement, growth and survival of mussels, environmental and socio-economic) and 3 predefined scenarios representing provisional goals of mussel cultivation: spat production, biomass production and bioremediation. The relative importance of each criterion was assessed utilizing the Analytical Hierarchy Process. Site suitability index was calculated and the final result of the site selection analysis was summarized for 3 scenarios and overall suitability map. Four suitability classes (unsuitable, least, moderately and most suitable) were applied, and 3 most suitable zones for provisional zebra mussel cultivation with 12 candidate sites were selected accordingly. The integrated approach presented in this study can be adjusted for designating zebra mussel farming sites in other estuarine lagoon ecosystems, or cultivation of other mussel species for bioremediation purposes. The analytical framework and the workflow designed in this study are also adoptable for addressing other aquaculture-related spatial planning issues. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site.

    Directory of Open Access Journals (Sweden)

    Dominik Marchowski

    Full Text Available The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700. In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014 from the whole ORE (523 km2 of water, we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2 in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32. We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.

  10. The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site.

    Science.gov (United States)

    Marchowski, Dominik; Neubauer, Grzegorz; Ławicki, Łukasz; Woźniczka, Adam; Wysocki, Dariusz; Guentzel, Sebastian; Jarzemski, Maciej

    2015-01-01

    The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.

  11. ASSESSING THE IMPACT OF CONTINUOUS BACTERIAL TREATMENTS OVER A TWO-WEEK PERIOD ON ZEBRA MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2001-07-17

    These experiments indicated that in waters at 23 C the window of opportunity to kill zebra mussels with bacterial strain CL0145A is limited to the first two days of treatment. Treatments beyond two days will not increase mortality.

  12. Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates

    International Nuclear Information System (INIS)

    De Jonge, M.; Belpaire, C.; Geeraerts, C.; De Cooman, W.; Blust, R.; Bervoets, L.

    2012-01-01

    The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. - Highlights: ► The use of tissue concentrations to assess environmental metal pollution was studied. ► Metal accumulation was measured in caged zebra mussels and resident Chironomidae. ► Shell condition of mussels and macroinvertebrate taxa distribution was assessed. ► Different accumulation between biota and relations with community level were found. ► Bioaccumulation is an integrated measure of metal toxicity in aquatic communities. - Metal accumulation in selected aquatic invertebrates can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity.

  13. Preliminary characterization of digestive enzymes in freshwater mussels

    Science.gov (United States)

    Sauey, Blake W.; Amberg, Jon J.; Cooper, Scott T.; Grunwald, Sandra K.; Newton, Teresa J.; Haro, Roger J.

    2015-01-01

    Resource managers lack an effective chemical tool to control the invasive zebra mussel Dreissena polymorpha. Zebra mussels clog water intakes for hydroelectric companies, harm unionid mussel species, and are believed to be a reservoir of avian botulism. Little is known about the digestive physiology of zebra mussels and unionid mussels. The enzymatic profile of the digestive glands of zebra mussels and native threeridge (Amblema plicata) and plain pocketbook mussels (Lampsilis cardium) are characterized using a commercial enzyme kit, api ZYM, and validated the kit with reagent-grade enzymes. A linear correlation was shown for only one of nineteen enzymes, tested between the api ZYM kit and a specific enzyme kit. Thus, the api ZYM kit should only be used to make general comparisons of enzyme presence and to observe trends in enzyme activities. Enzymatic trends were seen in the unionid mussel species, but not in zebra mussels sampled 32 days apart from the same location. Enzymatic classes, based on substrate, showed different trends, with proteolytic and phospholytic enzymes having the most change in relative enzyme activity.

  14. The Effects of Zebra Mussels (Dreissena polymorpha) on the Foraging Success of Eurasian Perch (Perca fluviatilis) and Ruffe (Gymnocephalus cernuus)

    Science.gov (United States)

    Dieterich, Axel; Mörtl, Martin; Eckmann, Reiner

    2004-07-01

    Complex habitat structures can influence the foraging success of fish. Competition for food between fish species can therefore depend on the competitors' abilities to cope with structural complexity. In laboratory experiments, we comparatively assessed effects of zebra mussels (Dreissena polymorpha Pall.) on the foraging success of Eurasian perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus (L.)). In single-species and mixed-species experiments, the fish were fed caddisfly larvae (Tinodes waeneri (L.)) over complex (mussel-covered stones) and less-complex (bare stones) substrates. With intraspecific competition, food consumption by perch and ruffe decreased significantly when the complex substrate was used. With interspecific competition, food consumption by perch and ruffe did not change with substrate complexity, but perch clearly out-competed ruffe on both substrates. Zebra mussel beds provide a refuge for macrozoobenthos against predation by ruffe and probably also by perch. (

  15. Seasonal abundances of naked amoebae in biofilms on shells of zebra mussels (Dreissena polymorpha) with comparative data from rock scrapings.

    Science.gov (United States)

    Bischoff, Paul J; Wetmore, Scott

    2009-01-01

    In North America, zebra mussels (Dreissena polymorpha) are notoriously known as invasive species. The abundance of naked amoebae sampled from the shells of zebra mussels was compared with abundances from rock scrapings at approximately monthly intervals for 1 year. The sites were 2 km apart along the same shoreline. No significant difference in abundance of naked amoebae (F = 1.44; P

  16. Quagga and zebra mussel risk via veliger transfer by overland hauled boats

    Directory of Open Access Journals (Sweden)

    Larry B. Dalton

    2013-04-01

    Full Text Available Invasive quagga and zebra mussels (Dreissena rostriformis bugensis and Dreissena polymorpha, respectively pose a great threat to USwaters. Recreational boats constitute a significant risk for spreading the organisms. Recreational boats circulate large amounts of raw waterwhen in use, and if not drained and dried correctly can transport many mussel larvae, called veligers. Veligers experience very high mortality rates; however, the number of potentially transported veligers can be a serious risk to non-infested bodies of water, especially if multiple boats are involved. The risk of veliger transport was calculated for Lake Mead and Lake Michigan using boat capacities for water circulation and specific veliger density data. Results illustrate the importance of draining, drying, and/or decontaminating recreational boats after use.

  17. Genotoxic effects induced by the exposure to an environmental mixture of illicit drugs to the zebra mussel.

    Science.gov (United States)

    Parolini, Marco; Magni, Stefano; Castiglioni, Sara; Binelli, Andrea

    2016-10-01

    Despite the growing interest on the presence of illicit drugs in freshwater ecosystems, just recently the attention has been focused on their potential toxicity towards non-target aquatic species. However, these studies largely neglected the effects induced by exposure to complex mixtures of illicit drugs, which could be different compared to those caused by single psychoactive molecules. This study was aimed at investigating the genetic damage induced by a 14-day exposure to a realistic mixture of the most common illicit drugs found in surface waters worldwide (cocaine, benzoylecgonine, amphetamine, morphine and 3,4-methylenedioxymethamphetamine) on the zebra mussel (Dreissena polymorpha). The mixture caused a significant increase of DNA fragmentation and triggered the apoptotic process and micronuclei formation in zebra mussel hemocytes, pointing out its potential genotoxicity towards this bivalve species. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Invasive zebra mussels (Driessena polymorpha) and Asian clams (Corbicula fluminea) survive gut passage of migratory fish species: implications for dispersal

    Science.gov (United States)

    Gatlin, Michael R.; Shoup, Daniel E.; Long, James M.

    2013-01-01

    The introduction and spread of invasive species is of great concern to natural resource managers in the United States. To effectively control the spread of these species, managers must be aware of the multitude of dispersal methods used by the organisms. We investigated the potential for survival through the gut of a migrating fish (blue catfish, Ictalurus furcatus) as a dispersal mechanism for two invasive bivalves: zebra mussel (Driessena polymorpha) and Asian clam (Corbicula fluminea). Blue catfish (N = 62) were sampled over several months from Sooner Lake, Oklahoma, transported to a laboratory and held in individual tanks for 48 h. All fecal material was collected and inspected for live mussels. Survival was significantly related to water temperature in the lake at the time of collection, with no mussels surviving above 21.1 C°, whereas 12 % of zebra mussels (N = 939) and 39 % of Asian clams (N = 408) consumed in cooler water survived gut passage. This research demonstrates the potential for blue catfish to serve as a dispersal vector for invasive bivalves at low water temperatures.

  19. A cost-benefit analysis of preventative management for zebra and quagga mussels in the Colorado-Big Thompson System

    Science.gov (United States)

    Thomas, Catherine M.

    2010-01-01

    Zebra and quagga mussels are fresh water invaders that have the potential to cause severe ecological and economic damage. It is estimated that mussels cause $1 billion dollars per year in damages to water infrastructure and industries in the United States (Pimentel et al., 2004). Following their introduction to the Great Lakes in the late 1980s, mussels spread rapidly throughout the Mississippi River Basin and the Eastern U.S. The mussel invasion in the West is young. Mussels were first identified in Nevada in 2007, and have since been identified in California, Arizona, Colorado, Utah, and Texas. Western water systems are very different from those found in the East. The rapid spread of mussels through the eastern system was facilitated by connected and navigable waterways. Western water systems are less connected and are characterized by man-made reservoirs and canals. The main vector of spread for mussels in the West is overland on recreational boats (Bossenbroek et al., 2001). In response to the invasion, many western water managers have implemented preventative management programs to slow the overland spread of mussels on recreational boats. In Colorado, the Colorado Department of Wildlife (CDOW) has implemented a mandatory boat inspection program that requires all trailered boats to be inspected before launching in any Colorado water body. The objective of this study is to analyze the costs and benefits of the CDOW boat inspection program in Colorado, and to identify variables that affect the net benefits of preventative management. Predicting the potential economic benefits of slowing the spread of mussels requires integrating information about mussel dispersal potential with estimates of control costs (Keller et al., 2009). Uncertainty surrounding the probabilities of establishment, the timing of invasions, and the damage costs associated with an invasion make a simulation model an excellent tool for addressing "what if" scenarios and shedding light on the

  20. Review on methods of golden mussel control in pires

    Directory of Open Access Journals (Sweden)

    Edemir Luiz Kowalski

    2008-07-01

    Full Text Available At the beginning of the 90’s, they were detected in Rio da Prata in Argentina the first samples of the exotic specie named limnoperna fortunei, from Asia, maybe introduced through ballast water of ships came from Asia. In Brazil the first samples were detected in Lagoa dos Patos in Rio Grande do Sul in the 90’s, possibly by the same reason. A second axis was verified in Campo Grande in Mato Grosso do Sul derived probably from Argentina because of the navigation through the Paraguay river going down to Lagoa de Itaipú causing its contamination. The invader specie has the capacity of fouling pipings where the contaminated water circulates, causing considerable financial damage to the infected industries. In Brazil the indrustries located in Rio Grande do Sul as well as hydroelectric plants as Itaipu, they manage these problems stopping the equipments for their maintenance and cleaning more times than the habitual. The United States of America and Canada already have the same kind of problem with the similar specie found here in Brazil. The target of this work is to introduce a review about the main methods to control the golden mussel mollusk without using any kind of chemical products, based on The USA and Canada’s experiences, where there are similar problems but with the specie zebra mussel. Key-words: Non Chemicals Methods, Golden Mussel, Zebra Mussel

  1. Variations in zebra mussel (Dreissena polymorpha) veliger densities throughout 1996 at Dam 52 on the lower Ohio River

    Science.gov (United States)

    Reed, Darren P.; Herod, Jeffrey J.; Sickel, James B.

    1998-01-01

    Zebra mussel veliger densities were monitored throughout 1996 at Lock and Dam 52 on the lower Ohio River near Brookport, IL. The spawning season occurred between mid June and early September with veliger densities peaking at 30,000/m3 in late June. Veliger first appeared at a water temperature of 21° C. When spawning ended in September the water temperature was 22 °C. Veligers were found throughout November when the water temperature was 10 °C. The lowest temperature at which veligers were observed was 7 ° C in March 1996. These results show that the zebra mussels in the lower Ohio River are reproducing naturally and that spawning appears to be synchronous. The presence of larvae at low temperatures in March suggests that veligers are capable of delaying settlement and overwintering in the planktonic stage.

  2. Evaluation of uptake and chronic toxicity of virgin polystyrene microbeads in freshwater zebra mussel Dreissena polymorpha (Mollusca: Bivalvia).

    Science.gov (United States)

    Magni, Stefano; Gagné, François; André, Chantale; Della Torre, Camilla; Auclair, Joëlle; Hanana, Houda; Parenti, Camilla Carla; Bonasoro, Francesco; Binelli, Andrea

    2018-08-01

    Microplastics (MPs), plastic debris smaller than 5mm, are widely found in both marine and freshwater ecosystems. However, few studies regarding their hazardous effects on inland water organisms, have been conducted. For this reason, the aim of our research was the evaluation of uptake and chronic toxicity of two mixtures (MIXs) of virgin polystyrene microbeads (PMs) of 10μm and 1μm in size (MIX 1, with 5×10 5 of 1μmsizePMs/L and 5×10 5 of 10μmsizePMs/L, and MIX 2 with 2×10 6 of 1μmsizePMs/L and 2×10 6 of 10μmsizePMs/L) on freshwater zebra mussel Dreissena polymorpha (Mollusca: Bivalvia) during 6 exposure days. The PM uptake in the mussel body and hemolymph was assessed using confocal microscopy, while the chronic toxicity of PMs was evaluated on exposed mussels using a comprehensive battery of biomarkers of cellular stress, oxidative damage and neuro- genotoxicity. Confocal microscopy analyses showed that MPs concentrated in the gut lumen of exposed mussels, absorbed and transferred firstly in the tissues and then in the hemolymph. The results revealed that PMs do not produce oxidative stress and genetic damage, with the exception of a significant modulation of catalase and glutathione peroxidase activities in mussels exposed to MIX 1. Regarding neurotoxicity, we observed only a significant increase of dopamine concentration in mussels exposed to both MIXs, suggesting a possible implication of this neurotransmitter in an elimination process of accumulated PMs. This research represents a first study about the evaluation of virgin MP toxicity in zebra mussel and more research is warranted concerning the long term neurological effects of virgin MPs. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  3. Metallothionein (MT) response after chronic palladium exposure in the zebra mussel, Dreissena polymorpha

    International Nuclear Information System (INIS)

    Frank, Sabrina N.; Singer, Christoph; Sures, Bernd

    2008-01-01

    The effects of different exposure concentrations of palladium (Pd) on relative metallothionein (MT) response and bioaccumulation were investigated in zebra mussels (Dreissena polymorpha). The mussels were exposed to 0.05, 5, 50, and 500 μg/L Pd 2+ for 10 weeks under controlled temperature and fasting conditions. Relative MT contents were assessed by a modified Ag-saturation method, which allows to discriminate between MT bound to Pd (Pd-MT) and MT bound to unidentified metals (Ag-MT). Determination of metal contents resulted from atomic absorption spectrometry following a microwave digestion. For unexposed mussels and mussels exposed to 0.05 μg/L Pd no metal accumulation could be detected. All other exposure concentrations resulted in detectable Pd accumulation in mussels with final tissue concentrations of 96 μg/g (500 μg/L), 45 μg/g (50 μg/L), and 9 μg/g (5 μg/L). Compared with initial levels Pd-MT concentrations at the end of the exposure period were 600 (500 μg/L), 160 (50 μg/L), and 27 (5 μg/L) times higher. These results show that an increase in MTs in D. polymorpha already occurs at relatively low aqueous Pd concentrations indicating that there is the need for detoxification of Pd in the mussel. Furthermore, correlations between Ag-MT and Pd accumulation indicate that higher exposure concentrations are associated with adverse effects on the mussels. Thus, harmful effects of chronic Pd exposure of organisms even in lowest concentrations cannot be excluded in the environment

  4. Lessons from a transplantation of zebra mussels into a small urban river: An integrated ecotoxicological assessment.

    Science.gov (United States)

    Bourgeault, A; Gourlay-Francé, C; Vincent-Hubert, F; Palais, F; Geffard, A; Biagianti-Risbourg, S; Pain-Devin, S; Tusseau-Vuillemin, M-H

    2010-10-01

    It is often difficult to evaluate the level of contamination in small urban rivers because pollution is mainly diffuse, with low levels of numerous substances. The use of a coupled approach using both chemical and biological measurements may provide an integrated evaluation of the impact of micro-pollution on the river. Zebra mussels were transplanted along a metal and organic pollution gradient in spring 2008. For two months, mussels and water samples were collected from two sites every two weeks and analyzed for metal and PAH content as well as water physicochemical parameters. Diffusive gradients in thin film (DGT) were also used to assess levels of labile metals. Exposure of mussels to contaminants and potential impact were evaluated using physiological indices and various biomarkers including condition index (CI), defense mechanisms (glutathione-S-transferase: GST), digestive enzymes (amylase and cellulase) and genotoxicity (micronucleus test: MN and comet assay: CA). For most contaminants, the water contamination was significantly higher downstream. Bioaccumulation in zebra mussels was related to water contamination in the framework of the biodynamic model, which allowed us to take into account the biological dilution that was caused by the growth of soft tissue downstream. Thus, metal influxes were on average two times higher downstream than upstream in particular for Zn, Cr, Cu and Cd. Significant differences in condition index were observed (final CI was 0.42 ± 0.03 downstream and 0.31 ± 0.03 upstream) reflecting a better food availability downstream. Moreover a significant decrease of GST activity and digestive enzymes activity in the cristalline style was observed downstream. Interpreting this decrease requires considering not only micro-pollution but also the trophic status related to the water's physicochemistry. The MN test and the CA on gill cells highlighted genotoxicity in mussels transplanted downstream compared to upstream. © 2010 Wiley

  5. Use of zebra mussel (dreissena polymorpha) to assess trace metals in river water

    International Nuclear Information System (INIS)

    Anzano, J.; Lasheras, R.J.; Bonilla, A.; Anwar, J.

    2007-01-01

    Ebro river (Spain) has been fairly contaminated by industrial effluents: The toxicity level of the river due to heavy metals has been monitored by analyzing zebra mussels (Dreissena Polymorpha) samples as bioindicator. To access the level of toxicity ten metals (AI, Cd, Cr, Cu, Fe, Ni, Pb, Se, Sn and Zn) were determined by Voltamperometry. The conditions of determination were optimized for each metal prior to determination. Aqueous solutions of metals concerned were used as standards in detenpinations. (author)

  6. Underwater cleaning techniqued used for removal of zebra mussels at the FitzPatrick Nuclear Power Plant

    International Nuclear Information System (INIS)

    Hobbs, B.; Kahabka, J.

    1995-01-01

    This paper discusses the use of a mechanical brush cleaning technology recently used to remove biofouling from the Circulating Water (CW) System at New York Power Authority's James A. FitzPatrick Nuclear Power Plant. The FitzPatrick plant had previously used chemical molluscicide to treat zebra mussels in the CW system. Full system treatment was performed in 1992 with limited forebay/screenwell treatment in 1993. The New York Power Authority (NYPA) decided to conduct a mechanical cleaning of the intake system in 1994. Specific project objectives included: (1) Achieve a level of surface cleaniness greater than 98%; (2) Remove 100% of debris, both existing sediment and debris generated as a result of cleaning; (3) Inspect all surfaces and components, identifying any problem areas; (4) Complete the task in a time frame within the 1994-95 refueling outage schedule window, and; (5) Determine if underwater mechanical cleaning is a cost-effective zebra mussel control method suitable for future application at FitzPatrick. A pre-cleaning inspection, including underwater video photography, was conducted of each area. Cleaning was accomplished using diver-controlled, multi-brush equipment included the electro-hydraulic powered Submersible Cleaning and Maintenance Platform (SCAMP), and several designs of hand-held machines. The brushes swept all zebra mussels off surfaces, restoring concrete and metal substrates to their original condition. Sensitive areas including pump housings, standpipes, sensor piping and chlorine injection tubing, were cleaned without degradation. Submersible vortex vacuum pumps were used to remove debris from the cavity. More than 46,000 ft 2 of surface area was cleaned and over 460 cubic yards of dewatered debris were removed. As each area was completed, a post-clean inspection with photos and video was performed

  7. Adverse effects induced by ecgonine methyl ester to the zebra mussel: A comparison with the benzoylecgonine

    International Nuclear Information System (INIS)

    Parolini, Marco; Binelli, Andrea

    2013-01-01

    Cocaine and its metabolites are the prevalent psychotropic substances in aquatic environment. However, to date the knowledge on their adverse effects to non-target organisms is inadequate. The aims of this study were to investigate sub-lethal effects induced by the ecgonine methyl ester (EME) to the freshwater bivalve Dreissena polymorpha and to compare its toxicity to that by benzoylecgonine (BE), the other main cocaine metabolite. EME sub-lethal effects were investigated by 14 days in-vivo exposures and a multi-biomarker approach. Slight variations in biomarker responses were found at 0.15 μg/L treatment. 0.5 μg/L EME treatment induced destabilization of lysosome membranes, an overall inactivation of defense enzymes, increases in lipid peroxidation, protein carbonylation and DNA fragmentation, but no variations in fixed genetic damage. The use of a biomarker response index (BRI) showed that at 0.5 μg/L both cocaine metabolites had the same toxicity to zebra mussels specimens. -- Highlights: •Sub-lethal effects induced by ecgonine methyl ester (EME) to D. polymorpha were investigated. •Realistic EME concentrations caused notable adverse effects in treated bivalves. •EME induced oxidative injuries to treated-mussel lipids, protein and DNA. •EME toxicity was comparable to the benzoylecgonine one. -- Environmentally relevant ecgonine methyl ester concentrations induced adverse effects to zebra mussels

  8. The ecology and impact of the invasion of Lake Ontario by the zebra mussel (Dreissena polymorpha) and quagga mussel (D. bugensis)

    Science.gov (United States)

    Negley, T.L.; Mills, E.L.; Baldwin, B.; O'Gorman, R.; Owens, R.W.; Munawar, M.

    2003-01-01

    In this chapter we present a detailed description of the zebra and quagga mussel invasion in Lake Ontario, with specific emphasis on: (1) the development of the Dreissena populations in Lake Ontario, (2) previously unreported data from 1997 and 1998 for Dreissena populations at Nine-Mile Point in Lake Ontario, (3) factors influencing dreissenid development in Lake Ontario, and (4) the effects of dreissenid colonization on the biota of the Lake Ontario ecosystem.

  9. Impact of the zebra mussel Dreissena polymorpha invasion on the budget of suspended material in a shallow lagoon ecosystem

    Science.gov (United States)

    Daunys, Darius; Zemlys, Petras; Olenin, Sergej; Zaiko, Anastasija; Ferrarin, Christian

    2006-05-01

    The role of the zebra mussel Dreissena polymorpha in redistribution of total particulate material (TPM) between the water column and bottom sediment was estimated using the TPM budget for a mussel bed in the Curonian lagoon, the Baltic Sea. Seasonal clearance rates were derived from the TPM budget assuming two resuspension scenarios: no resuspension and full resuspension of biodeposits. Estimated clearance rates for both scenarios were compared with the rates calculated from the population clearance rate model. Seasonal clearance rates estimated using the population model (1.1 and 11.8 l g-1 SFDW day-1) fitted well into the interval of seasonal clearance rates calculated from TPM budgets assuming no resuspension of biodeposits (3.2 and 21.4 l g SFDW-1 day-1). In the scenario with biodeposits resuspension clearance rates were much higher (57.4 and 148.9 g SFDW-1 day-1). The ratio of clearance to residence time was highly dependent on the fate of biodeposits. Therefore its use in interpretation of the species impact on TPM was limited. An alternative measure based on the ratio of the amount of TPM biodeposited to TPM transported into the bed was used. It was found that zebra mussels are able to deposit between 10 and 30% of the incoming TPM, and the amount of biodeposited material was correlated with water residence time. Results indicate that the impact of zebra mussels on TPM in the lagoon is small relative to the high transport rates of TPM over the bed. However, annual biosedimentation rate (~590 g m-2) in the mussel bed was higher than physical deposition rate (~380 g m-2) in accumulation areas devoid of large suspension feeders. We suggest that a local impact due to enhanced availability of organic material to other trophic groups of associated benthic organisms may be more significant than effects on TPM pathways at an ecosystem scale.

  10. Phylogeography and systematics of zebra mussels and related species.

    Science.gov (United States)

    Gelembiuk, Gregory W; May, Gemma E; Lee, Carol Eunmi

    2006-04-01

    The genus Dreissena includes two widespread and aggressive aquatic invaders, the zebra mussel, Dreissena polymorpha, and the quagga mussel, Dreissena bugensis. This genus evolved in the Ponto-Caspian Sea basin, characterized by dynamic instability over multiple timescales and a unique evolutionary environment that may predispose to invasiveness. The objectives of this study were to gain insights into the demographic history of Dreissena species in their endemic range, to reconstruct intraspecific phylogeographic relationships among populations, and to clarify systematics of the genus, using DNA sequences from the mitochondrial cytochrome oxidase I (COI) gene. We found four deeply diverged clades within this genus, with a basal split that approximately coincided with the Cretaceous-Tertiary boundary. Divergence events within the four base clades were much more recent, corresponding to geographically disjunct sets of populations, which might represent species complexes. Across all taxa, populations of Dreissena shared a common pattern of genetic signatures indicating historical population bottlenecks and expansions. Haplotype diversity was relatively low in Ponto-Caspian drainages relative to more stable tectonic lakes in Greece, Macedonia, and Turkey. The phylogeographic and demographic patterns in the endemic range of Dreissena might have resulted from vicariance events, habitat instability, and the high fecundity and passive dispersal of these organisms.

  11. Food intake rates and habitat segregation of tufted duck Aythya fuligula scaup Aythya marila exploiting zebra mussels Dreissena Polymorpha

    NARCIS (Netherlands)

    Leeuw, de J.J.

    1999-01-01

    The foraging skills of Tufted Duck Aythya fuligula and Scaup Aythya marila feeding on Zebra Mussels Dreissena polymorpha were studied in experiments under semi-natural diving conditions with relevance to the IJsselmeer/Markermeer area (large lakes in the centre of The Netherlands, former Zuiderzee

  12. Modelling the Risk Posed by the Zebra Mussel Dreissena polymorpha: Italy as a Case Study.

    Science.gov (United States)

    Bosso, Luciano; De Conno, Carmelina; Russo, Danilo

    2017-08-01

    We generated a risk map to forecast the potential effects of the spreading of zebra mussels Dreissena polymorpha across the Italian territory. We assessed the invader's potential impact on rivers, lakes, watersheds and dams at a fine-grained scale and detected those more at risk that should be targeted with appropriate monitoring. We developed a MaxEnt model and employed weighted overlay analyses to detect the species' potential distribution and generate risk maps for Italy. D. polymorpha has a greater probability of occurring at low to medium altitudes in areas characterised by fluviatile deposits of major streams. Northern and central Italy appear more at risk. Some hydroelectric power dams are at high risk, while most dams for irrigation, drinkable water reservoirs and other dam types are at medium to low risk. The lakes and rivers reaches (representing likely expansion pathways) at medium-high or high risk mostly occur in northern and central Italy. We highlight the importance of modelling potential invasions on a country scale to achieve the sufficient resolution needed to develop appropriate monitoring plans and prevent the invader's harmful effects. Further high-resolution risk maps are needed for other regions partly or not yet colonised by the zebra mussel.

  13. Modelling the Risk Posed by the Zebra Mussel Dreissena polymorpha: Italy as a Case Study

    Science.gov (United States)

    Bosso, Luciano; De Conno, Carmelina; Russo, Danilo

    2017-08-01

    We generated a risk map to forecast the potential effects of the spreading of zebra mussels Dreissena polymorpha across the Italian territory. We assessed the invader's potential impact on rivers, lakes, watersheds and dams at a fine-grained scale and detected those more at risk that should be targeted with appropriate monitoring. We developed a MaxEnt model and employed weighted overlay analyses to detect the species' potential distribution and generate risk maps for Italy. D. polymorpha has a greater probability of occurring at low to medium altitudes in areas characterised by fluviatile deposits of major streams. Northern and central Italy appear more at risk. Some hydroelectric power dams are at high risk, while most dams for irrigation, drinkable water reservoirs and other dam types are at medium to low risk. The lakes and rivers reaches (representing likely expansion pathways) at medium-high or high risk mostly occur in northern and central Italy. We highlight the importance of modelling potential invasions on a country scale to achieve the sufficient resolution needed to develop appropriate monitoring plans and prevent the invader's harmful effects. Further high-resolution risk maps are needed for other regions partly or not yet colonised by the zebra mussel.

  14. Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates.

    Science.gov (United States)

    De Jonge, M; Belpaire, C; Geeraerts, C; De Cooman, W; Blust, R; Bervoets, L

    2012-12-01

    The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Food intake rates and habitat segregation of tufted duck Aythya fuligula and scaup Aythya marila exploiting zebra mussels Dreissena polymorpha

    NARCIS (Netherlands)

    De Leeuw, JJ

    1999-01-01

    The foraging skills of Tufted Duck Aythya fuligula and Scaup Aythya marila feeding on Zebra Mussels Dreissena polymorpha were studied in experiments under seminatural diving conditions with relevance to the IJssalmeer/Markermeer area (large lakes in the centre of The Netherlands, former Zuiderzee

  16. Variations in gene expression levels in four European zebra mussel, Dreissena polymorpha, populations in relation to metal bioaccumulation: A field study.

    Science.gov (United States)

    Kerambrun, E; Rioult, D; Delahaut, L; Evariste, L; Pain-Devin, S; Auffret, M; Geffard, A; David, E

    2016-12-01

    The present study was performed to validate the suitability of using gene expression in zebra mussels, Dreissena polymorpha, for biomonitoring of freshwater environment. Mussels were collected in four French rivers (Meuse, Moselle, Oise and Vilaine) in spring and autumn. Relative gene expression of 9 candidate genes involved in cellular metabolic activities (Cytochrome-c-oxidase - cox, and ATP synthase - atp), detoxification process (Metallothionein - mt and Glutathion-S-Transferase - gst), oxidative stress (Catalase - cat, Superoxyde Dismutase - sod and Glutathion peroxidase - gpx) and digestive functions (Amylase - amy and Cellulase - ghf) were measured in digestive gland. Metal bioaccumulation in tissues and morphometric parameters were also analyzed to interpret molecular responses. All our results are consistent with different physiological reactions to environmental condition between zebra mussel populations. In spring, the levels of mt, sod, gpx, cat, atp, amy and ghf relative expression were significantly higher in mussels with the lowest metal bioaccumulation (the Meuse) compared to at least one of the other sites. In autumn, this higher expression levels in Meuse River were still observed for gpx, cat, atp and amy. This study has also pointed out different sources of variability in gene expression (individual size, season, trophic resources and origin of mussels) which are inevitable in natural fluctuant environment. This underlines the importance to take them into account in field study to propose a correct interpretation of biomarker responses. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Population dynamics of zebra mussels Dreissena polymorpha (Pallas, 1771) during the initial invasion of the Upper Mississippi River, USA

    Science.gov (United States)

    Cope, W.G.; Bartsch, M.R.; Hightower, J.E.

    2006-01-01

    The aim of this study was to document and model the population dynamics of zebra mussels Dreissena polymorpha (Pallas, 1771) in Pool 8 of the Upper Mississippi River (UMR), USA, for five consecutive years (1992-1996) following their initial discovery in September 1991. Artificial substrates (concrete blocks, 0.49 m2 surface area) were deployed on or around the first of May at two sites within each of two habitat types (main channel border and contiguous backwater). Blocks were removed monthly (30 ?? 10 d) from the end of May to the end of October to obtain density and growth information. Some blocks deployed in May 1995 were retrieved in April 1996 to obtain information about overwinter growth and survival. The annual density of zebra mussels in Pool 8 of the UMR increased from 3.5/m2 in 1992 to 14,956/m 2 in 1996. The average May-October growth rate of newly recruited individuals, based on a von Bertalanffy growth model fitted to monthly shell-length composition data, was 0.11 mm/d. Model estimates of the average survival rate varied from 21 to 100% per month. Estimated recruitment varied substantially among months, with highest levels occurring in September-October of 1994 and 1996, and in July of 1995. Recruitment and density in both habitat types increased by two orders of magnitude in 1996. Follow-up studies will be necessary to assess the long-term stability of zebra mussel populations in the UMR; this study provides the critical baseline information needed for those future comparisons. ?? Published by Oxford University Press on behalf of The Malacological Society of London 2006.

  18. Field biomonitoring using the zebra mussel Dreissena polymorpha and the quagga mussel Dreissena bugensis following immunotoxic reponses. Is there a need to separate the two species?

    Science.gov (United States)

    Evariste, Lauris; David, Elise; Cloutier, Pierre-Luc; Brousseau, Pauline; Auffret, Michel; Desrosiers, Mélanie; Groleau, Paule Emilie; Fournier, Michel; Betoulle, Stéphane

    2018-04-02

    The zebra mussel, Dreissena polymorpha constitutes an extensively used sentinel species for biomonitoring in European and North American freshwater systems. However, this invasive species is gradually replaced in freshwater ecosystem by Dreissena bugensis, a closely related dreissenid species that shares common morphological characteristics but possess some physiological differences. However, few are known about differences on more integrated physiological processes that are generally used as biomarkers in biological monitoring studies. Declining of zebra mussel populations raises the question of the sustainability of using one or both species indifferently to maintain the quality of environmental pollution monitoring data. In our study, we performed a field comparative study measuring immune-related markers and bioaccumulation of PCBs, PAHs and PBDEs in sympatrically occurring mussel populations from three sites of the St. Lawrence River. For tested organisms, species were identified using RFLP analysis. Measurement of bioaccumulated organic compounds indicated a higher accumulation of PCBs and PBDEs in D. bugensis soft tissues compared to D. polymorpha while no differences were noticed for PAHs. Results of hemocytic parameters highlighted that differences of hemocyte distributions were associated to modulations of phagocytic activities. Moreover, marked differences occurred in measurement of hemocytic oxidative activity, indicating divergences between the two species for ROS regulation strategies. This physiological characteristic may deeply influence species responses facing environmental or pollution related stress and induce bias if the two species are not differentiated in further biomarker or bioaccumulation measurement-based studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Heterozygosity and fitness: No strong association in Great Lakes populations of the zebra mussel, Dreissena Polymorpha (Pallas)

    Science.gov (United States)

    Lewis, K.M.; Feder, J.L.; Horvath, T.G.; Lamberti, G.A.

    2000-01-01

    A number of studies have found positive associations between allozyme heterozygosity and fitness surrogates (e.g., body size and growth rate) for marine molluscs. We investigated whether similar relationships exist for freshwater populations of the zebra mussel, Dreissena polymorpha. Only one significant correlation between multi-locus heterozygosity and shell length was observed for a total of 22 D. polymorpha populations surveyed from midwestern U.S.A. lakes and streams, and the result was not significant on a table-wide basis. Meta-analysis revealed a significant common correlation coefficient (effect magnitude) between multi-locus heterozygosity and shell length across all 22 sites (rc = 0.052, P = 0.019, 1557 df). However, the variance in shell length explained by multi-locus heterozygosity was small (rc2 = 0.0027), implying a weak causal relationship if any. Also, we saw no relationship between heterozygosity and growth rate in a one-year field enclosure experiment. A significant heterozygosity-shell length correlation previously reported for a zebra mussel population at Put-in-Bay, Lake Erie, Ohio, may have been the product of unique population dynamics, rather than natural selection. Similar demographic considerations may contribute to inconsistencies in heterozygosity-fitness correlations seen for other molluscs.

  20. Accumulation of metals, polycyclic (halogenated) aromatic hydrocarbons, and biocides in zebra mussel and eel from the Rhine and Meuse rivers

    Energy Technology Data Exchange (ETDEWEB)

    Hendriks, A.J. [RIZA, Lelystad (Netherlands). Inst. for Inland Water Management and Waste Water Treatment; Pieters, H.; Boer, J. de [DLO-Netherlands Inst. for Fisheries Research, IJmuiden (Netherlands)

    1998-10-01

    Concentrations of heavy metals and various groups of organic microcontaminants were measured in zebra mussel and eel from the Rhine-Meuse basin. Residues in mussel from the Rhine and Meuse were on average 2.3 and 2.9 times higher than in those from the reference location of IJsselmeer. Total body burdens of organic microcontaminants in mussel and eel varied between 0.05 to 0.07 mmol/kg fat weight in six out of seven samples. The largest contribution in mussels and eel came from polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), respectively. Concentrations of bromodiphenyl-ethers, chlorobenzenes, chloronitrobenzenes, chloroterphenyls, and chlorobenzyltoluenes were lower. Total polybrominated biphenyl residues appear lower than total PCB levels. The largest chlorobiocide residues were noted for 4,4{prime}-DDE, toxaphene, trichlorophenylmethane, and {gamma}-hexachlorocyclohexane. An extraordinary high body burden of 1.2 mmol/kg fat weight, largely consisting of acenaphthene, was observed in one sample. Ratios of concentrations in organism fat and dry organic suspended solids varied between 1 and 10 for traditionally monitored organochlorines, independent of the octanol-water partition coefficient. The values did not deviate significantly from a value of about 3.3, expected for equilibrium partitioning of persistent chemicals. Lower values were observed for PAHs and some chloro(nitro)benzenes. Most ratios of concentrations in eel and mussel fat were within the range of 1 to 10, also largely independent of K{sub ow}. Yet, values tended to be higher at K{sub ow} > 10{sup 6}. Ratios below 1 were noted for pentabromodiphenylether, pentachloro(thio)anisol, chlorobenzyltoluenes, and some chloronitrobenzenes, chlorobiphenyls, and chlorobiocides. These field data confirm recent modeling efforts on bioconcentration and biomagnification. For heavy metals, atomic mass explained 67% of the variation in zebra mussel residues.

  1. Seasonal and PAH impact on DNA strand-break levels in gills of transplanted zebra mussels.

    Science.gov (United States)

    Michel, Cécile; Bourgeault, Adeline; Gourlay-Francé, Catherine; Palais, Frédéric; Geffard, Alain; Vincent-Hubert, Françoise

    2013-06-01

    Genotoxicity endpoints are useful tools to biomonitor the physicochemical and biological quality of aquatic ecosystems. A caging study on the freshwater bivalve Dreissena polymorpha was planned to run over four seasons in the Seine River basin in order to assess whether DNA damage measured in transplanted mussels to polluted area vary according to seasonal changes. Three sites were chosen along the Seine River, one upstream from Paris and two downstream, corresponding to a chemical gradient of water contamination. The DNA strand break (comet assay) and chromosomal damage (micronucleus test) were measured in caged mussels at each site and in winter, spring and summer, along with PAH water contamination, PAH bioaccumulation, the mussel condition index (CI), the gonado-somatic index (GSI) and the filtration rate (FR). The level of DNA strand break measured in winter was low and increased in spring, concomitantly with FR and GSI. Over the same period, micronucleus (MN) frequency and PAH bioaccumulation decreased significantly in caged mussels, with both parameters positively correlated to each other. DNA strand-break levels and MN frequencies showed inter-site variations corresponding to the chemical contamination gradient. These two genotoxicity endpoints usefully complement each other in field studies. These results show that the MN test and comet assay, when applied to gill cells of caged zebra mussels, are sensitive tools for freshwater genotoxicity monitoring. Copyright © 2013. Published by Elsevier Inc.

  2. Wintering Tufted Ducks Aythya fuligula diving for zebra mussels Dreissena polymorpha balance feeding costs within narrow margins of their energy budget

    NARCIS (Netherlands)

    Leeuw, de J.J.; Eerden, van M.R.; Visser, G.H.

    1999-01-01

    Diving ducks face the strongly cooling properties of aquatic environments. In experiments with Tufted Ducks Aythya fuligula feeding on zebra mussels Dreissena polymorpha in outdoor cages, we measured changes in food consumption and diving behaviour in relation to water temperature (3-22°C). Water

  3. Wintering Tufted Ducks Aythya fuligula diving for zebra mussels Dreissena polymorpha balance feeding costs within narrow margins of their energy budget

    NARCIS (Netherlands)

    de Leeuw, JJ; van Eerden, MR; Visser, GH

    Diving ducks face the strongly cooling properties of aquatic environments. In experiments with Tufted Ducks Aythya fuligula feeding on zebra mussels Dreissena polymorpha in outdoor cages, we measured changes in food consumption and diving behaviour in relation to water temperature (3-22 degrees C).

  4. Microsatellite loci for dreissenid mussels (Mollusca: Bivalvia: Dreissenidae) and relatives: markers for assessing exotic and native populations.

    Science.gov (United States)

    Feldheim, Kevin A; Brown, Joshua E; Murphy, Douglas J; Stepien, Carol A

    2011-07-01

    We developed and tested 14 new polymorphic microsatellite loci for dreissenid mussels, including the two species that have invaded many freshwater habitats in Eurasia and North America, where they cause serious industrial fouling damage and ecological alterations. These new loci will aid our understanding of their genetic patterns in invasive populations as well as throughout their native Ponto-Caspian distributions. Eight new loci for the zebra mussel Dreissena polymorpha polymorpha and six for the quagga mussel D. rostriformis bugensis were compared with new results from six previously published loci to generate a robust molecular toolkit for dreissenid mussels and their relatives. Taxa tested include D. p. polymorpha, D. r. bugensis, D. r. grimmi, D. presbensis, the 'living fossil'Congeria kusceri, and the dark false mussel Mytilopsis leucophaeata (the latter also is invasive). Overall, most of the 24 zebra mussel (N = 583) and 13 quagga mussel (N = 269) population samples conformed to Hardy-Weinberg equilibrium expectations for the new loci following sequential Bonferroni correction. The 11 loci (eight new, three previously published) evaluated for D. p. polymorpha averaged 35.1 alleles and 0.72 mean observed heterozygosity per locus, and 25.3 and 0.75 for the nine loci (six new, three previously published) developed for D. r. bugensis. All but three of these loci successfully amplified the other species of Dreissena, and all but one also amplified Congeria and Mytilopsis. All species and populations tested were significantly divergent using the microsatellite data, with neighbour-joining trees reflecting their evolutionary relationships; our results reveal broad utility for resolving their biogeographic, evolutionary, population and ecological patterns. © 2011 Blackwell Publishing Ltd.

  5. Origin of Spanish invasion by the zebra mussel, Dreissena polymorpha (Pallas, 1771) revealed by amplified fragment length polymorphism (AFLP) fingerprinting

    NARCIS (Netherlands)

    Rajagopal, S.; Pollux, B.J.A.; Peters, J.L.; Cremers, G.; Moon- van der Staay, S.Y.; Alen, van T.; Eygensteyn, J.; Hoek, van A.H.A.M.; Palau, A.; Vaate, de A.B.; Velde, van der G.

    2009-01-01

    The zebra mussel, Dreissena polymorpha is an aquatic nuisance invasive species originally native to the Ponto-Caspian region where it is found in lakes and delta areas of large rivers draining into the Black and Caspian seas. The dispersal of D. polymorpha began at the end of the 18th century, at a

  6. Temperature- and Turbidity-Dependent Competitive Interactions Between Invasive Freshwater Mussels.

    Science.gov (United States)

    Huang, Qihua; Wang, Hao; Ricciardi, Anthony; Lewis, Mark A

    2016-03-01

    We develop a staged-structured population model that describes the competitive dynamics of two functionally similar, congeneric invasive species: zebra mussels and quagga mussels. The model assumes that the population survival rates are functions of temperature and turbidity, and that the two species compete for food. The stability analysis of the model yields conditions on net reproductive rates and intrinsic growth rates that lead to competitive exclusion. The model predicts quagga mussel dominance leading to potential exclusion of zebra mussels at mean water temperatures below [Formula: see text] and over a broad range of turbidities, and a much narrower set of conditions that favor zebra mussel dominance and potential exclusion of quagga mussels at temperatures above [Formula: see text] and turbidities below 35 NTU. We then construct a two-patch dispersal model to examine how the dispersal rates and the environmental factors affect competitive exclusion and coexistence.

  7. Zebra Mussel Farming in the Szczecin (Oder Lagoon: Water-Quality Objectives and Cost-Effectiveness

    Directory of Open Access Journals (Sweden)

    Gerald Schernewski

    2012-06-01

    Full Text Available The Oder (Szczecin Lagoon in the southern Baltic Sea is a heavily eutrophicated and degraded coastal ecosystem. We applied a systems approach framework to critically evaluate whether existing water-management measures achieve water-quality objectives for the river and lagoon systems. Our simulations reveal that the existing water-quality objectives for the river and the coastal waters are not sufficiently complementary. We suggest new water-quality threshold concentrations, which are in agreement with the European Water Framework Directive, and we calculate acceptable maximum nutrient loads for the Oder River. These calculations suggest that external nutrient-load reductions in the river basin alone seem insufficient to achieve good water quality in the lagoon. A comprehensive eutrophication management approach should also include internal nutrient-retention and nutrient-removal measures in the lagoon. We focus on mussel farming, i.e., that of zebra mussels, Dreissena polymorpha, because they are efficient in removing nutrients and improving water transparency in the Oder Lagoon. For this purpose, the ecosystem model ERGOM is extended by a mussel module and an economic model. The economic model describes costs and benefits of mussel cultivation depending on the the farm size. We included additional potential sources of income such as water-quality tax or emission certificates. The simulations show that mussel farming in the lagoon is a suitable supportive measure and, at a load-reduction target of 50% or more, it is a cost-efficient measure for removing nutrients and for implementing the Baltic Sea Action Plan. In the Oder Lagoon, mussel farming could potentially remove nearly 1000 t of N (70 t of P/year, or about 2% of the present N and P loads, and it would have the additional benefit of improving water transparency.

  8. Linking Species Traits to the Abiotic Template of Flowing Waters: Contrasting Eco physiologies Underlie Displacement of Zebra Mussels by Quagga Mussels in a Large River-Estuary

    Science.gov (United States)

    Casper, A. F.

    2005-05-01

    The St. Lawrence River-Estuary was the gateway of entry for dreissenids to North America and holds some of the oldest populations. The St. Lawrence also has four distinct physical-chemical water masses (a regional scale abiotic template) that both species inhabit. Despite their ecological similarities, quagga mussels are supplanting zebra mussels in much of their shared range. In order to try to better understand the changing distributions of these two species we compared glycogen, shell mass and tissue biomass in each of the water masses. This comparative physiological combined with experimental approaches (estuarine salinity experiments and reciprocal transplants) showed that while quagga mussels should dominate in most habitats, that abiotic/bioenergetic constraints in two regions (the Ottawa River plume and the freshwater-marine transition zone) might prevent them from dominating these locations. These findings are an example of how the interaction of landscape scale abiotic heterogeneity and a species-specific physiology can have strong impacts of distribution of biota large rivers.

  9. Assessment of the Water Quality Conditions at Ed Zorinsky Reservoir and the Zebra Mussel (Dreissena polymorpha) Population Emerged after the Drawdown of the Reservoir and Management Implications for the District’s Papillion and Salt Creek Reservoirs

    Science.gov (United States)

    2012-04-23

    Lansky, 2000). Where they have been surveyed in lentic enviroments , adult zebra mussels occurrence is less abundant at near surface depths (Mackie...be specified. Soft substrates (i.e., soil ) were surveyed less extensively. Since Zorinsky Lake experiences significant seasonal thermal...Riprap: 29.4% Soil : 5.0% Depicted aerial view of Area B1 showing the locations of found zebra mussel shells. (Red line indicates normal

  10. Effects of zebra mussels on food webs: Interactions with juvenile bluegill and water residence time

    Science.gov (United States)

    Richardson, W.B.; Bartsch, L.A.

    1997-01-01

    We evaluated how water residence time mediated the impact of zebra mussels Dreissena polymorpha and bluegill sunfish Lepomis macrochirus on experimental food webs established in 1100-1 outdoor mesocosms. Water residence time was manipulated as a surrogate for seston resupply - a critical variable affecting growth and survival of suspension-feeding invertebrates. We used a 2 x 2 x 2 factorial experimental design with eight treatment combinations (3 replicates/treatment) including the presence or absence of Dreissena (2000 per m2), juvenile bluegill (40 per mesocosm), and short (1100 1 per d) or long (220 1 per d) water residence time. Measures of seston concentration (chlorophyll a, turbidity and suspended solids) were greater in the short- compared to long water-residence mesocosms, but intermediate in short water-residence mesocosms containing Dreissena. Abundance of rotifers (Keratella and Polyarthra) was reduced in Dreissena mesocosms and elevated in short residence time mesocosms. Cladocera abundance, in general, was unaffected by the presence of Dreissena; densities were higher in short-residence time mesocosms, and reduced in the presence of Lepomis. The growth of juvenile Lepomis were unaffected by Dreissena because of abundant benthic food. The final total mass of Dreissena was significantly greater in short- than long-residence mesocosms. Impacts of Dreissena on planktonic food webs may not only depend on the density of zebra mussels but also on the residence time of the surrounding water and the resupply of seston. ?? 1997 Kluwer Academic Publishers.

  11. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy).

    Science.gov (United States)

    Binelli, A; Guzzella, L; Roscioli, C

    2008-06-01

    Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with summation operatorPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447ngg(-1) lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47>-99>-100>-209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide.

  12. CRAYFISH PREDATION EXPERIMENTS ON THE INTRODUCED ZEBRA MUSSEL, DREISSENA POLYMORPHA, IN IRELAND, AND THEIR POTENTIAL FOR BIOCONTROL.

    OpenAIRE

    REYNOLDS J. D.; DONOHOE R.

    2001-01-01

    The zebra mussel Dreissena polymorpha, native to the Aralo-Caspian region, has spread across Europe in the last 180 years. Although it reached England in 1820, it only arrived in Ireland in around 1995, probably attached to the hull of pleasure boats, and since then has spread through the lowland Shannon and Erne systems, which are linked by canal. While White-clawed crayfish Austropotamobius pallipes (Lereboullet) occur in these systems, Dreissena has not yet colonized sites with large crayf...

  13. Zebra mussels (Dreissena polymorpha) as a biomonitor of trace elements along the southern shoreline of Lake Michigan.

    Science.gov (United States)

    Shoults-Wilson, W Aaron; Elsayed, Norhan; Leckrone, Kristen; Unrine, Jason

    2015-02-01

    The invasive zebra mussel (Dreissena polymorpha) has become an accepted biomonitor organism for trace elements, but it has yet to be studied along the Lake Michigan shoreline. Likewise, the relationships between tissue concentrations of elements, organism size, and sediment concentrations of elements have not been fully explained. The present study found that a variety of allometric variables such as length, dry tissue mass, shell mass, organism condition indices, and shell thickness index were useful in explaining intrasite variability in elemental concentrations. The flesh condition index (grams of tissue dry mass per gram of shell mass) explained variability at the most sites for most elements. Once allometric intrasite variability was taken into account, additional significant differences were found between sites, although the net effect was small. Significant positive relationships between sediment and tissue concentrations were found for Pb and Zn, with a significant negative relationship for Cd. It was also found that Cu and Zn concentrations in tissues increased significantly along the shoreline in the southeasterly direction, whereas Hg increased in a northwesterly direction. Opportunistic sampling found that zebra mussels accumulate significantly higher concentrations of nearly all elements analyzed compared to Asian clams (Corbicula fluminea) at the same site. The present study demonstrates the need to fully explain natural sources of variability before using biomonitors to explain spatial distributions of trace elements. © 2014 SETAC.

  14. Ophryoglena hemophaga n. sp. (Ciliophora: Ophryoglenidae): a parasite of the digestive gland of zebra mussels Dreissena polymorpha.

    Science.gov (United States)

    Molloy, Daniel P; Lynn, Denis H; Giamberini, Laure

    2005-07-18

    Ophryoglena hemophaga n. sp. is described from a freshwater Dreissena polymorpha population in the Rhine delta of the Netherlands. This is the first ophryoglenine species (order Hymenostomatida, suborder Ophryoglenina) recorded as a molluscan parasite. As is typical of ciliates in the suborder Ophryoglenina, O. hemophaga exhibits a polymorphic life history with cystment and reproduction by palintomy. Trophonts were observed within digestive gland lumina, and zebra mussel hemocytes were present in some of their digestive vacuoles. The presence of a single, longitudinal tract of multiple contractile vacuoles represents its most unique feature and distinguishes it from all other described Ophryoglena spp. The number of somatic kineties of O. hemophaga (range 100 to 124) is also distinguishing as it is one of the lowest for [corrected] an Ophryoglena sp. Other characteristics of this species include: ovoid to elongate trophonts 96 to 288 microm in length, with an elongate macronucleus 41 to 65 microm in length; tomonts 50 to 150 microm in diameter producing a clear mucous cyst envelope, whose thickness is approximately half of the tomont diameter; elongated theronts 96 to 131 microm in length which emerge after 1 to 3 cell divisions taking 36 to 48 h at 20 +/- 3 degrees C. Protomonts and theronts are, respectively, negatively and positively phototactic--characteristics that likely aid in maintenance of infection in zebra mussel populations.

  15. Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

    Science.gov (United States)

    Farsad, Nikrooz

    Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the byssus revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

  16. Comparing a microbial biocide and chlorine as zebra mussel control strategies in an Irish drinking water treatment plant

    OpenAIRE

    Sara Meehan; Frances E. Lucy; Bridget Gruber; Sarahann Rackl

    2013-01-01

    A need exists for an environmentally friendly mussel control method to replace chlorine and other traditional control methods currentlyutilised in drinking water plants and other infested facilities. Zequanox® is a newly commercialised microbial biocide for zebra and quaggamussels comprised of killed Pseudomonas fluorescens CL145A cells. The objective of this study was to compare the efficacy of adevelopmental formulation of Zequanox (referred to as MBI 401 FDP) and chlorine treatments on adu...

  17. Competitive replacement of invasive congeners may relax impact on native species: interactions among zebra, quagga, and native unionid mussels.

    Science.gov (United States)

    Burlakova, Lyubov E; Tulumello, Brianne L; Karatayev, Alexander Y; Krebs, Robert A; Schloesser, Donald W; Paterson, Wendy L; Griffith, Traci A; Scott, Mariah W; Crail, Todd; Zanatta, David T

    2014-01-01

    Determining when and where the ecological impacts of invasive species will be most detrimental and whether the effects of multiple invaders will be superadditive, or subadditive, is critical for developing global management priorities to protect native species in advance of future invasions. Over the past century, the decline of freshwater bivalves of the family Unionidae has been greatly accelerated by the invasion of Dreissena. The purpose of this study was to evaluate the current infestation rates of unionids by zebra (Dreissena polymorpha) and quagga (D. rostriformis bugensis) mussels in the lower Great Lakes region 25 years after they nearly extirpated native unionids. In 2011-2012, we collected infestation data for over 4000 unionids from 26 species at 198 nearshore sites in lakes Erie, Ontario, and St. Clair, the Detroit River, and inland Michigan lakes and compared those results to studies from the early 1990 s. We found that the frequency of unionid infestation by Dreissena recently declined, and the number of dreissenids attached to unionids in the lower Great Lakes has fallen almost ten-fold since the early 1990s. We also found that the rate of infestation depends on the dominant Dreissena species in the lake: zebra mussels infested unionids much more often and in greater numbers. Consequently, the proportion of infested unionids, as well as the number and weight of attached dreissenids were lower in waterbodies dominated by quagga mussels. This is the first large-scale systematic study that revealed how minor differences between two taxonomically and functionally related invaders may have large consequences for native communities they invade.

  18. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Binelli, A. [Department of Biology, Via Celoria 26, University of Milan, 20133 Milan (Italy)], E-mail: andrea.binelli@unimi.it; Guzzella, L.; Roscioli, C. [IRSA-CNR, 20047 Brugherio (Milan) (Italy)

    2008-06-15

    Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with {sigma}PBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447 ng g{sup -1} lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47 > -99 > -100 > -209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide. - This study shows the first data of PBDE contamination in freshwater invertebrates from Mediterranean basin.

  19. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

    International Nuclear Information System (INIS)

    Binelli, A.; Guzzella, L.; Roscioli, C.

    2008-01-01

    Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with ΣPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447 ng g -1 lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47 > -99 > -100 > -209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide. - This study shows the first data of PBDE contamination in freshwater invertebrates from Mediterranean basin

  20. Evaluation of several priority pollutants in zebra mussels (Dreissena polymorpha) in the largest Italian subalpine lakes

    International Nuclear Information System (INIS)

    Riva, Consuelo; Binelli, Andrea; Provini, Alfredo

    2008-01-01

    Zebra mussel (Dreissena polymorpha) has been used for the biomonitoring of several POPs (PCBs, DDTs, HCB and HCHs) in the largest Italian subalpine great lakes (Lake Maggiore, Garda, Como, Iseo and Lugano). Samplings were carried out in April 2003 at 15 locations selected according to industrial and anthropic levels of lakes. Results have pointed out high DDT levels in D. polymorpha specimens from Lake Maggiore (700-1400 ng/g lipids, 5-9 times higher than those measured in mussels of other Italian lakes), due to a contamination from a chemical plant located on one of the main lake inlet that occurred in 1996. On the contrary, PCB levels (400-2509 ng/g lipids) highlighted an overall pollution, with some sporadic peaks of contamination. Data showed a moderate increase trend compared to those found in a previous monitoring campaign carried out in 1996. Future monitoring is needed in order to confirm this tendency. - Significant levels of DDTs and PCBs are still present in the Italian subalpine great lakes

  1. Parasitism can be a confounding factor in assessing the response of zebra mussels to water contamination.

    Science.gov (United States)

    Minguez, Laëtitia; Buronfosse, Thierry; Beisel, Jean-Nicolas; Giambérini, Laure

    2012-03-01

    Biological responses measured in aquatic organisms to monitor environmental pollution could be also affected by different biotic and abiotic factors. Among these environmental factors, parasitism has often been neglected even if infection by parasites is very frequent. In the present field investigation, the parasite infra-communities and zebra mussel biological responses were studied up- and downstream a waste water treatment plant in northeast France. In both sites, mussels were infected by ciliates and/or intracellular bacteria, but prevalence rates and infection intensities were different according to the habitat. Concerning the biological responses differences were observed related to the site quality and the infection status. Parasitism affects both systems but seemed to depend mainly on environmental conditions. The influence of parasites is not constant, but remains important to consider it as a potential confounding factor in ecotoxicological studies. This study also emphasizes the interesting use of integrative indexes to synthesize data set. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Evaluation of several priority pollutants in zebra mussels (Dreissena polymorpha) in the largest Italian subalpine lakes

    Energy Technology Data Exchange (ETDEWEB)

    Riva, Consuelo [Department of Biology, Ecology Section, University of Milan, Via Celoria 26, 20133 Milan (Italy)], E-mail: consuelo.riva@unimi.it; Binelli, Andrea; Provini, Alfredo [Department of Biology, Ecology Section, University of Milan, Via Celoria 26, 20133 Milan (Italy)

    2008-02-15

    Zebra mussel (Dreissena polymorpha) has been used for the biomonitoring of several POPs (PCBs, DDTs, HCB and HCHs) in the largest Italian subalpine great lakes (Lake Maggiore, Garda, Como, Iseo and Lugano). Samplings were carried out in April 2003 at 15 locations selected according to industrial and anthropic levels of lakes. Results have pointed out high DDT levels in D. polymorpha specimens from Lake Maggiore (700-1400 ng/g lipids, 5-9 times higher than those measured in mussels of other Italian lakes), due to a contamination from a chemical plant located on one of the main lake inlet that occurred in 1996. On the contrary, PCB levels (400-2509 ng/g lipids) highlighted an overall pollution, with some sporadic peaks of contamination. Data showed a moderate increase trend compared to those found in a previous monitoring campaign carried out in 1996. Future monitoring is needed in order to confirm this tendency. - Significant levels of DDTs and PCBs are still present in the Italian subalpine great lakes.

  3. Cellular energy allocation in zebra mussels exposed along a pollution gradient: linking cellular effects to higher levels of biological organization

    International Nuclear Information System (INIS)

    Smolders, R.; Bervoets, L.; Coen, W. de; Blust, R.

    2004-01-01

    Organisms exposed to suboptimal environments incur a cost of dealing with stress in terms of metabolic resources. The total amount of energy available for maintenance, growth and reproduction, based on the biochemical analysis of the energy budget, may provide a sensitive measure of stress in an organism. While the concept is clear, linking cellular or biochemical responses to the individual and population or community level remains difficult. The aim of this study was to validate, under field conditions, using cellular energy budgets [i.e. changes in glycogen-, lipid- and protein-content and mitochondrial electron transport system (ETS)] as an ecologically relevant measurement of stress by comparing these responses to physiological and organismal endpoints. Therefore, a 28-day in situ bioassay with zebra mussels (Dreissena polymorpha) was performed in an effluent-dominated stream. Five locations were selected along the pollution gradient and compared with a nearby (reference) site. Cellular Energy Allocation (CEA) served as a biomarker of cellular energetics, while Scope for Growth (SFG) indicated effects on a physiological level and Tissue Condition Index and wet tissue weight/dry tissue weight ratio were used as endpoints of organismal effects. Results indicated that energy budgets at a cellular level of biological organization provided the fastest and most sensitive response and energy budgets are a relevant currency to extrapolate cellular effects to higher levels of biological organization within the exposed mussels. - Exposure of zebra mussels along a pollution gradient has adverse effects on the cellular energy allocation, and results can be linked with higher levels of biological organization

  4. Cellular energy allocation in zebra mussels exposed along a pollution gradient: linking cellular effects to higher levels of biological organization

    Energy Technology Data Exchange (ETDEWEB)

    Smolders, R.; Bervoets, L.; Coen, W. de; Blust, R

    2004-05-01

    Organisms exposed to suboptimal environments incur a cost of dealing with stress in terms of metabolic resources. The total amount of energy available for maintenance, growth and reproduction, based on the biochemical analysis of the energy budget, may provide a sensitive measure of stress in an organism. While the concept is clear, linking cellular or biochemical responses to the individual and population or community level remains difficult. The aim of this study was to validate, under field conditions, using cellular energy budgets [i.e. changes in glycogen-, lipid- and protein-content and mitochondrial electron transport system (ETS)] as an ecologically relevant measurement of stress by comparing these responses to physiological and organismal endpoints. Therefore, a 28-day in situ bioassay with zebra mussels (Dreissena polymorpha) was performed in an effluent-dominated stream. Five locations were selected along the pollution gradient and compared with a nearby (reference) site. Cellular Energy Allocation (CEA) served as a biomarker of cellular energetics, while Scope for Growth (SFG) indicated effects on a physiological level and Tissue Condition Index and wet tissue weight/dry tissue weight ratio were used as endpoints of organismal effects. Results indicated that energy budgets at a cellular level of biological organization provided the fastest and most sensitive response and energy budgets are a relevant currency to extrapolate cellular effects to higher levels of biological organization within the exposed mussels. - Exposure of zebra mussels along a pollution gradient has adverse effects on the cellular energy allocation, and results can be linked with higher levels of biological organization.

  5. Competitive replacement of invasive congeners may relax impact on native species: interactions among zebra, quagga, and native unionid mussels.

    Directory of Open Access Journals (Sweden)

    Lyubov E Burlakova

    Full Text Available Determining when and where the ecological impacts of invasive species will be most detrimental and whether the effects of multiple invaders will be superadditive, or subadditive, is critical for developing global management priorities to protect native species in advance of future invasions. Over the past century, the decline of freshwater bivalves of the family Unionidae has been greatly accelerated by the invasion of Dreissena. The purpose of this study was to evaluate the current infestation rates of unionids by zebra (Dreissena polymorpha and quagga (D. rostriformis bugensis mussels in the lower Great Lakes region 25 years after they nearly extirpated native unionids. In 2011-2012, we collected infestation data for over 4000 unionids from 26 species at 198 nearshore sites in lakes Erie, Ontario, and St. Clair, the Detroit River, and inland Michigan lakes and compared those results to studies from the early 1990 s. We found that the frequency of unionid infestation by Dreissena recently declined, and the number of dreissenids attached to unionids in the lower Great Lakes has fallen almost ten-fold since the early 1990s. We also found that the rate of infestation depends on the dominant Dreissena species in the lake: zebra mussels infested unionids much more often and in greater numbers. Consequently, the proportion of infested unionids, as well as the number and weight of attached dreissenids were lower in waterbodies dominated by quagga mussels. This is the first large-scale systematic study that revealed how minor differences between two taxonomically and functionally related invaders may have large consequences for native communities they invade.

  6. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu.

    Science.gov (United States)

    Zhong, Huan; Kraemer, Lisa; Evans, Douglas

    2013-10-15

    Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ((65)Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65-91%) to Cu bioaccumulation is always higher than that from sediments (9-35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Biofouling leads to reduced shell growth and flesh weight in the cultured mussel Mytilus galloprovincialis.

    Science.gov (United States)

    Sievers, Michael; Fitridge, Isla; Dempster, Tim; Keough, Michael J

    2013-01-01

    Competitive interactions between cultured mussels and fouling organisms may result in growth and weight reductions in mussels, and compromised aquaculture productivity. Mussel ropes were inoculated with Ciona intestinalis, Ectopleura crocea or Styela clava, and growth parameters of fouled and unfouled Mytilus galloprovincialis were compared after two months. Small mussels (≈ 50 mm) fouled by C. intestinalis and E. crocea were 4.0 and 3.2% shorter in shell length and had 21 and 13% reduced flesh weight, respectively, compared to the controls. Large mussels (≈ 68 mm) fouled by S. clava, C. intestinalis and E. crocea were 4.4, 3.9 and 2.1% shorter than control mussels, respectively, but flesh weights were not significantly reduced. A series of competitive feeding experiments indicated that S. clava and C. intestinalis did not reduce mussels' food consumption, but that E. crocea, through interference competition, did. Fouling by these species at the densities used here reduced mussel growth and flesh weight, likely resulting in economic losses for the industry, and requires consideration when developing biofouling mitigation strategies.

  8. Impact of zebra and quagga mussels (Dreissena spp.) on freshwater unionids (Bivalvia: Unionidae) in the Detroit River of the Great Lakes

    Science.gov (United States)

    Schloesser, D.W.; Kovalak, W.P.; Longton, G.D.; Ohnesorg, K.L.; Smithee, R.D.

    1998-01-01

    To assess the impact of zebra and quagga mussel (Dreissena spp.) infestation on unionids, unionids (Bivalvia: Unionidae) were sampled in the Detroit River in 1982-1983, before mussels invaded the river, and in 1992 and 1994, after mussels invaded the river. Live unionids at four stations along the southeastern shore accounted for 97% (20 species) of all shells collected in 1982-1983, whereas live unionids accounted for only 10% (13 species) in 1992. A similar decline in live unionids occurred at nine stations along the northwestern shore, except the decline occurred over the three sampling periods: in 1982-83, 84% (22 species) were live; in 1992, 65% (26 species) were live; and, in 1994, only 3% (13 species) were live. The difference in time to near-total mortality of unionids along the southeastern and northwestern shores is attributed to differences in the time of invasion and abundance of zebra mussel veligers in distinct water masses emanating from Lake St. Clair located immediately upstream of the Detroit River. Although individuals of all species of all unionid subfamilies declined between 1982 and 1992/1994, members of the subfamilies Anodontinae and Lampsilinae declined more than Ambleminae. Between 1986 and 1992/1994, five Anodontinae, three Lampsilinae and 0 Ambleminae species have been extirpated from the river due to dreissenid mussel infestation. Numbers of individuals of commonly found species declined more than numbers of individuals of uncommonly found species. However, the number of uncommon species declined 47% (17 to 9) along both the southeastern and northwestern shores, whereas common species remained the same (3 species) along the southeastern shore and declined only 40% (5 to 3 species) along the northwestern shore. This study, and others, suggest that high mortality of unionids can occur between 4 and 6 yr after initial invasion by dreissenids or up to 8 yr depending on water current patterns. Infestation-induced mortality of unionids in the

  9. Exposure of zebra mussels to extracorporeal shock waves demonstrates formation of new mineralized tissue inside and outside the focus zone.

    Science.gov (United States)

    Sternecker, Katharina; Geist, Juergen; Beggel, Sebastian; Dietz-Laursonn, Kristin; de la Fuente, Matias; Frank, Hans-Georg; Furia, John P; Milz, Stefan; Schmitz, Christoph

    2018-04-03

    The success rate of extracorporeal shock wave therapy (ESWT) for fracture nonunions in human medicine (i.e., radiographic union at six months after ESWT) is only approximately 75%. Detailed knowledge regarding the underlying mechanisms that induce bio-calcification after ESWT is limited. We analyzed the biological response within mineralized tissue of a new invertebrate model organism, the zebra mussel Dreissena polymorpha , after exposure with extracorporeal shock waves (ESWs). Mussels were exposed to ESWs with positive energy density of 0.4 mJ/mm 2 (A) or were sham exposed (B). Detection of newly calcified tissue was performed by exposing the mussels to fluorescent markers. Two weeks later, the A-mussels showed a higher mean fluorescence signal intensity within the shell zone than the B-mussels (pmussels was independent of the size and position of the focal point of the ESWs. These data demonstrate that induction of bio-calcification after ESWT may not be restricted to the region of direct energy transfer of ESWs into calcified tissue. The results of the present study are of relevance for better understanding of the molecular and cellular mechanisms that induce formation of new mineralized tissue after ESWT. © 2018. Published by The Company of Biologists Ltd.

  10. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Huan, E-mail: huanzhong1982@hotmail.com [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada); Nanjing University, School of Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province (China); Kraemer, Lisa; Evans, Douglas [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada)

    2013-10-15

    Highlights: • Mussels exposed to algal/sediment-Cu have different size-related Cu accumulation. • Size-related Cu accumulation in mussels could be more dependant on algal-Cu uptake. • Importance of algal/sediment-Cu to Cu bioaccumulation varies with mussel body size. • Cu sources (algae and sediments) should be considered in “mussel watch” programs. • Cu stable isotope offers many advantages in Cu bioaccumulation studies. -- Abstract: Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ({sup 65}Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65–91%) to Cu bioaccumulation is always higher than that from sediments (9–35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5 mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors.

  11. Phosphorus addition reverses the positive effect of zebra mussels (Dreissena polymorpha) on the toxic cyanobacterium, Microcystis aeruginosa.

    Science.gov (United States)

    Sarnelle, Orlando; White, Jeffrey D; Horst, Geoffrey P; Hamilton, Stephen K

    2012-07-01

    We tested the hypothesis that zebra mussels (Dreissena polymorpha) have positive effects on the toxin-producing cyanobacterium, Microcystis aeruginosa, at low phosphorus (P) concentrations, but negative effects on M. aeruginosa at high P, with a large-scale enclosure experiment in an oligotrophic lake. After three weeks, mussels had a significantly positive effect on M. aeruginosa at ambient P (total phosphorus, TP ∼10 μg L⁻¹), and a significantly negative effect at high P (simulating a TP of ∼40 μg L⁻¹ in lakes). Positive and negative effects were strong and very similar in magnitude. Thus, we were able to ameliorate a negative effect of Dreissena invasion on water quality (i.e., promotion of Microcystis) by adding P to water from an oligotrophic lake. Our results are congruent with many field observations of Microcystis response to Dreissena invasion across ecosystems of varying P availability. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. DDT in zebra mussels from Lake Maggiore (N. Italy): level of contamination and endocrine disruptions.

    Science.gov (United States)

    Binelli, Andrea; Bacchetta, Renato; Mantecca, Paride; Ricciardi, Francesco; Provini, Alfredo; Vailati, Giovanni

    2004-08-10

    The DDT contamination of Lake Maggiore (Northern Italy) has been monitored since a serious pollution event occurred in 1996. To assess the environmental risk associated with this contamination, bioaccumulation data coupled with histopathological markers were evaluated on zebra mussel populations from two different contaminated sites from April 2001 to April 2002. Biomonitoring results showed high DDT pollution in 2001 because of a flood which transported DDTs still contained in the sediments of a polluted river to the lake. DDT concentrations reached values of 4-5 microg/g lipids, higher than those recorded in other industrialized countries but comparable to levels measured in developing ones. In the ovaries of the most highly polluted mussels, histological analyses showed a delay in oocyte maturation and a high incidence of pathological pictures mainly referable to oocyte degeneration and haemocytic infiltration. Moreover, despite the presence of mature sperms, in 2001 first male gamete release occurred about 2 months later than in females. These results indicated a neuroendocrine interference of DDT on Dreissena polymorpha reproduction and also showed that these invertebrates can be successfully used to evaluate ecological implications due to exposure to endocrine disruptors in freshwater environments.

  13. Dreissenid mussel research priorities workshop

    Science.gov (United States)

    Sytsma, Mark; Phillips, Stephen; Counihan, Timothy D.

    2015-01-01

    Currently, dreissenid mussels have yet to be detected in the northwestern part of the United States and western Canada. Infestation of one of the jurisdictions within the mussel-free Pacific Northwest would likely have significant economic, soci­etal and environmental implications for the entire region. Understanding the biology and environmental tolerances of dreissenid mussels, and effectiveness of various man­agement strategies, is key to prevention.On November 4-5, 2015, the Aquatic Bioinvasion Research and Policy Institute and the Center for Lakes and Reservoirs at Portland State University, the US Geological Survey, and the Pacific States Marine Fisheries Commission, convened a Dreissenid Mussel Research Priorities Workshop funded by the Great Northern Landscape Conservation Cooperative. The purpose of the workshop was to review dreissenid research priorities in the 2010 Quagga-Zebra Mussel Action Plan for Western U.S. Waters, reassess those priorities, incorporate new information and emerging trends, and develop priorities to strategically focus research efforts on zebra and quagga mussels in the Pacific Northwest and ensure that future research is focused on the highest priorities. It is important to note that there is some repetition among dreissenid research priority categories (e.g., prevention, detection, control, monitoring, and biology).Workshop participants with research experience in dreissenid mussel biology and management were identified by a literature review. State and federal agency managers were also invited to the workshop to ensure relevancy and practicality of the work­shop outcomes. A total of 28 experts (see sidebar) in mussel biology, ecology, and management attended the workshop.

  14. Organochlorine and trace element contamination in wintering and migrating diving ducks in the southern Great Lakes, USA, since the zebra mussel invasion

    Science.gov (United States)

    Custer, Christine M.; Custer, T.W.

    2000-01-01

    Because of the potential for increased trophic transfer of contaminants by zebra mussels (Dreissena sp.) to higher trophic levels, we collected four species of waterfowl (n = 65 ducks) from four locations in Lake Erie, Lake St. Clair, and Lake Michigan, USA, between 1991 and 1993 for organochlorine contaminant and trace element analyses. Geometric mean concentrations of total polychlorinated biphenyls (PCBs) and p,pa??-dichlorodiphenyldichloroethylene (DDE) were 1.35 and 0.15 I?g/g wet weight in lesser scaup (Aythya affinis) carcasses and were below known effect levels. Total PCBs in 80% of carcasses, however, were above the U.S. Food and Drug Administration's threshold of 3.0 I?g/g lipid weight for consumption of poultry. With the exception of selenium, trace elements were also at background or no-effect levels. Selenium concentrations in livers of 95% of lesser scaup, 90% of bufflehead (Bucephala albeola), and 72% of common goldeneye (Bucephala clangula) were in the elevated (>10 I?g/g dry wt) or potentially harmful range (>33 I?g/g dry wt). The effects of these high selenium concentrations are unknown but should be investigated further based on reproductive effects observed in field and laboratory studies of dabbling ducks and because lesser scaup populations are declining. Concentrations of total PCBs in dreissenid mussels in western Lake Erie were 10 times higher than in the upper Mississippi River but were similar to concentrations in other industrialized rivers in Europe and the United States. Metal concentrations were similar to other industrialized sites where zebra mussels have been sampled.

  15. Evaluating high pH for control of dreissenid mussels

    Directory of Open Access Journals (Sweden)

    Dave Evans

    2013-04-01

    Full Text Available Two field experiments were carried out using a custom built flow-through laboratory to test the effect of elevated pH on dreissenid musselsas a potential control method. Both experiments tested the ability of dreissenid pediveligers to settle under conditions of elevated pH and thelong-term survival of adult dreissenids under the same conditions. The two experimental sites had different water quality and differentspecies of dreissenids present. The settlement of quagga mussel pediveligers at the lower Colorado River was inhibited with increasing pH.At the maximum achieved pH of 9.1, there was approximately 90% reduction compared to the maximum settlement observed in the controls.Since the settlement was almost as low in pH 8.9 as at pH 9.1, the inhibition in settlement may have been due to the presence of a precipitateformed under high pH conditions rather than the increase in background pH. No mortality of quagga mussel adults was observed in theexperimental pH levels at the lower Colorado River. At San Justo Reservoir, zebra mussel settlement decreased with increasing pH. Newsettlement was almost entirely absent at the highest pH tested (pH 9.6. The observed mortality of adult zebra mussels was low, but did tendto increase with increasing pH. We also tested the response of adult zebra mussels to short-term exposure to very high pH levels (i.e. pH 10,11, and 12. Adult mussels in poor physical condition experienced 90% mortality after 12 hours at pH 12. For unstressed adult zebra mussels,90% mortality was reached after 120 hours at pH 12. Significant mortalities were also observed both at pH 10 and pH 11. From this study,we conclude that pH elevation could be used both as a preventative treatment to eliminate settlement by dreissenid mussels and as an end ofseason treatment to eliminate adults. The high pH treatment would have to be tailored to the site water quality to prevent formation ofprecipitate during treatment and to minimize corrosive

  16. Making the Best of a Pest: The Potential for Using Invasive Zebra Mussel (Dreissena Polymorpha) Biomass as a Supplement to Commercial Chicken Feed

    OpenAIRE

    McLaughlan, Claire; Rose, Paul; Aldridge, David C.

    2014-01-01

    Invasive non-native species frequently occur in very high densities. Where such invaders present an economic or ecological nuisance this biomass is typically removed and landfill is the most common destination, which is undesirable from both an economic and ecological perspective. The zebra mussel, Dreissena polymorpha, has invaded large parts of Europe and North America, and is routinely removed from raw water systems where it creates a biofouling nuisance. We investigated the suitability...

  17. The quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 – another Ponto-Caspian dreissenid bivalve in the southern Baltic catchment: the first record from the Szczecin Lagoon

    Directory of Open Access Journals (Sweden)

    Adam Woźniczka

    2016-04-01

    Full Text Available In 2014, a non-indigenous dreissenid bivalve, the quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 was for the first time recorded in the Szczecin Lagoon. This was also the first record of the species in the Baltic Sea catchment. The quagga mussel was found to accompany the zebra mussel (Dreissena polymorpha, a non-indigenous bivalve already firmly established in the Lagoon. As indicated by the new immigrant's estimated abundance (4000.0 ± 355.44 ind. m−2 and the zebra mussel to quagga mussel abundance ratio (about 60:40, the immigration of D. rostriformis bugensis to the Lagoon can be regarded as successful. The quagga mussel has already formed a strong and reproducing population which co-occurs with that of the zebra mussel in the area.

  18. A proteomic study using zebra mussels (D. polymorpha) exposed to benzo(α)pyrene: the role of gender and exposure concentrations.

    Science.gov (United States)

    Riva, Consuelo; Binelli, Andrea; Rusconi, Francesco; Colombo, Graziano; Pedriali, Alessandra; Zippel, Renata; Provini, Alfredo

    2011-07-01

    It has recently been established that the use of proteomics can be a useful tool in the field of ecotoxicology. Despite the fact that the mussel Dreissena polymorpha is a valuable bioindicator for freshwater ecosystems, the application of a proteomic approach with this organism has not been deeply investigated. To this end, several zebra mussel specimens were subjected to a 7-day exposure of two different concentrations (0.1 and 2 μg L⁻¹) of the model pollutant benzo[α]pyrene (B[α]P). Changes in protein expression profiles were investigated in gill cytosolic fractions from control/exposed male and female mussels using 2-DE electrophoresis. B[α]P bioaccumulation in mussel soft tissue was also assessed to validate exposure to the selected chemical. We evaluated overall changes in expression profiles for 28 proteins in exposed mussels, 16 and 12 of which were, respectively, over- and under-expressed. Surprisingly, the comparative analysis of protein data sets showed no proteins that varied commonly between the two different B[α]P concentrations. Spots of interest were manually excised and analysed by MALDI-TOF/TOF mass spectrometry. The most significant proteins that were identified as altered were related to oxidative stress, signal transduction, cellular structure and metabolism. This preliminary study indicates the feasibility of a proteomic approach with the freshwater mussel D. polymorpha and provides a starting point for similar investigations. Our results confirm the need to increase the number of invertebrate proteomic studies in order to increase the following: their representation in databases and the successful identification of their most relevant proteins. Finally, additional studies investigating the role of gender and protein modulation are warranted. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Bioaccumulation of heavy metals in the zebra mussel Dreissena polymorpha in the rivers Danube and Drau and its role as a bioindicator organism; Schwermetallbelastung von Dreissena polymorpha in Donau und Drau und ihre Bedeutung als Bioindikator

    Energy Technology Data Exchange (ETDEWEB)

    Luschuetzky, E.F. [Univ. Wien, Inst. fuer Zoologie, Abt. fuer Ultrastrukturforschung und Elektronenmikroskopie, Wien (Austria)

    2005-07-01

    Goal and scope. This study was undertaken to investigate the differences in heavy metal burden between the organisms and environmental compartments and to evaluate the role of Dreissena polymorpha as a bioindicator organism. Methods. The concentrations of zinc, copper, cadmium and lead in whole soft body and selected tissues of D. polymorpha at two river habitats in Austria were examined using atomic absorption spectroscopy (AAS). Concentrations in organisms were compared to those in sediment and water. Results and conclusion. Zebra mussels of the river Drau showed generally higher heavy metal concentrations as compared to mussels of the river Danube and contained elevated zinc and cadmium levels as compared to metal concentrations found in soft tissues of zebra mussels from uncontaminated sites in Germany and The Netherlands. The essential metals zinc and copper were mainly accumulated in gills, foot and byssal gland tissue of the mussel, in contrast to the non-essential metals cadmium and lead which were found predominantly in the midgut gland. The heavy metal concentrations in both, sediments and mussel tissue, were higher than in water samples. There was no correlation between the concentrations in water and in the organisms except for zinc. In contrast, correlations were found between concentrations in sediments and mussel soft tissue. Recommendation and perspective. Further investigations should include the examination of sediments and consider the mechanism of food uptake to assess the role of D. polymorpha as a bioindicator organism. (orig.)

  20. A Survey of Freshwater Mussels in the West Pearl River, Mississippi and Louisiana, 1995

    National Research Council Canada - National Science Library

    Miller, Andrew

    1997-01-01

    .... The nonindigenous zebra mussel, Dreissena polymorpha, introduced into the Great Lakes in the late 1980s, and the threatened mussel, Potamilus inflatus, listed as endangered, were not found although...

  1. Bibliography of Dreissena polymorpha (zebra mussels) and Dreissena rostriformis Bugensis (QUAGGA mussels): 1989 to 2011

    Science.gov (United States)

    Schloesser, Don W.; Schmuckal, Christine

    2012-01-01

    Dreissenid mussels invaded and colonized waters of the Laurentian Great Lakes during the late 1980s. Their colonization and resulting impact have been characterized as one of the most important ecological changes in freshwater systems in North America. The need for information on dreissenid mussels has grown during the past 2 decades, which has prompted the compilation of this bibliography. Two previous bibliographies of dreissenid mussels indicate average publication rates were 6 publications/year between 1771 and 1964 (1,180 in 194 y) and 30 publications/year between 1964 and 1993 (885 in 30 y). In the current bibliography, the average rate of publication doubled during the past 23 y (1989 to 2011) to 66 publications/year based on a total of 1,502 publications. These rates may be biased by increased numbers of researchers and journals over time but, at a minimum, these rates indicate continued interest and concern by humans about the impact of dreissenid mussels on water availability and the expanding range of dreissenids throughout the world. The current bibliography has a 94% efficiency rate for subject and 100% efficiency for title search criteria when compared with references in published studies of dreissenid mussels in 2011. In addition to publications, we included 206 student theses and 225 chapters in 26 books including 6 books devoted solely to dreissenid mussels. A vast majority of student theses were about dreissenid mussels in North America, especially in the Laurentian Great Lakes. The 6 books devoted to dreissenid mussels contained a variety of chapters that described biology, impact, control, and ecology of dreissenid mussels in both Europe (published in 1992 and 2010) and North America (1993, 1994, 1997, and 2000). In addition, there is a 7th book devoted solely to dreissenid mussels that is near completion.

  2. IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS

    International Nuclear Information System (INIS)

    Daniel Molloy

    2003-01-01

    Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there could be reduced ingestion of bacterial cells since they represent a reduced percentage of all particles ingested. Our tests indicated that a range of particle concentrations that might naturally exist in a turbid river did not inhibit mussel kill by the bacterial cells, but that an artificially high load of natural particles was capable of causing a reduction in kill. To be conservative, therefore, future pipe treatments should be timed to occur when intake waters have relatively low quantities of naturally suspended particulate matter

  3. IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Molloy

    2003-08-04

    Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there could be reduced ingestion of bacterial cells since they represent a reduced percentage of all particles ingested. Our tests indicated that a range of particle concentrations that might naturally exist in a turbid river did not inhibit mussel kill by the bacterial cells, but that an artificially high load of natural particles was capable of causing a reduction in kill. To be conservative, therefore, future pipe treatments should be timed to occur when intake waters have relatively low quantities of naturally suspended particulate matter.

  4. Phytoplankton Communities in Green Bay, Lake Michigan after Invasion by Dreissenid Mussels: Increased Dominance by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Bart T. De Stasio

    2014-11-01

    Full Text Available Biological invasions of aquatic systems disrupt ecological communities, and cause major changes in diversity and ecosystem function. The Laurentian Great Lakes of North America have been dramatically altered by such invasions, especially zebra (Dreissena polymorpha and quagga (D. rostriformis bugensis mussels. Responses to mussel invasions have included increased water clarity, and decreased chlorophyll and phytoplankton abundance. Although not all systems have responded similarly, in general, mussels have changed nutrient dynamics and physical habitat conditions. Therefore examination of different impacts can help us further understand mechanisms that underlie ecosystem responses to biological invasions. To aid our understanding of ecosystem impacts, we sampled established locations along a well-studied trophic gradient in Green Bay, Lake Michigan, after the 1993 zebra mussel invasion. A strong trophic gradient remained during the period sampled after the mussel invasion (2000–2012. However, mean summer chlorophyll increased and other measures of phytoplankton biomass (microscope and electronic cell counting did not change significantly. Multivariate analyses of phytoplankton community structure demonstrate a significant community shift after the invasion. Cyanobacteria increased in dominance, with Microcystis becoming the major summer taxon in lower Green Bay. Diatom diversity and abundance also increased and Chlorophyta became rare. Phytoplankton responses along the trophic gradient of Green Bay to zebra mussel invasion highlight the importance of mussel effects on nutrient dynamics and phytoplankton diversity and function.

  5. Inducibility of metallothionein biosynthesis in the whole soft tissue of zebra mussels Dreissena polymorpha exposed to cadmium, copper, and pentachlorophenol.

    Science.gov (United States)

    Ivanković, Dusica; Pavicić, Jasenka; Beatović, Vanja; Klobucar, Roberta Sauerborn; Klobucar, Göran Igor Vinko

    2010-04-01

    Freshwater mussels Dreissena polymorpha (Pallas, 1771) were exposed to the elevated concentrations of Cd (10, 50, 100, and 500 microg/L), Cu (10, 30, 50, and 80 microg/L), and an organochlorinated pesticide, pentachlorophenol (PCP) (1, 10, and 100 microg/L). Induced synthesis of biomarker metallothionein (MT) and changes in concentrations of cytosolic Cd, Cu, and Zn in the whole soft tissue of mussels were monitored after a 7-day laboratory exposure to the contaminants. A clear dose-dependent elevation in the MT concentration was observed after exposure to Cd at doses of 10-100 microg/L, and this increase of MT content was accompanied with a linear increase of cytosolic Cd. Cd concentration of 500 microg/L caused no additional increase of MT and Cd in mussel cytosol, suggesting possible toxic effects due to exceeding cellular inducible/defense capacity. Cu exposure resulted with variable changes in MT concentrations, with no clear linear relationship between MT and Cu concentrations in water, although a progressive dose-dependent accumulation of Cu in the soluble fraction of mussel tissues was recorded. A decrease of cytosolic Zn was evident at higher exposure concentrations of both metals used. PCP in concentrations applied was unable to induce MT synthesis, but the higher concentrations of PCP influenced the cytosolic metal concentrations. In conclusion, the results obtained confirm the specificity of MT induction in D. polymorpha as an biological response on metal stimulation, especially by cadmium, being more closely correlated to MT than copper within the ecologically relevant concentration range. The strong induction potential of cadmium as well as an absence of MT induction following exposure to PCP as an organic chemical contaminant are supporting evidences for usage of zebra mussel MT as a specific biomarker of Cd exposure in biomonitoring programs.

  6. Activation of AMP-activated protein kinase in response to temperature elevation shows seasonal variation in the zebra mussel, Dreissena polymorpha.

    Science.gov (United States)

    Jost, Jennifer A; Keshwani, Sarah S; Abou-Hanna, Jacob J

    2015-04-01

    Global climate change is affecting ectothermic species, and a variety of studies are needed on thermal tolerances, especially from cellular and physiological perspectives. This study utilized AMP-activated protein kinase (AMPK), a key regulator of cellular energy levels, to examine the effects of high water temperatures on zebra mussel (Dreissena polymorpha) physiology. During heating, AMPK activity increased as water temperature increased to a point, and maximum AMPK activity was detected at high, but sublethal, water temperatures. This pattern varied with season, suggesting that cellular mechanisms of seasonal thermal acclimatization affect basic metabolic processes during sublethal heat stress. There was a greater seasonal variation in the water temperature at which maximum AMPK activity was measured than in lethal water temperature. Furthermore, baseline AMPK activity varied significantly across seasons, most likely reflecting altered metabolic states during times of growth and reproduction. In addition, when summer-collected mussels were lab-acclimated to winter and spring water temperatures, patterns of heat stress mirrored those of field-collected animals. These data suggest that water temperature is the main driver of the seasonal variation in physiology. This study concluded that AMPK activity, which reflects changes in energy supply and demand during heat stress, can serve as a sensitive and early indicator of temperature stress in mussels. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Quagga mussels Dreissena rostriformis burgensis (Andrusov, 1897) in the Main River (Germany)

    NARCIS (Netherlands)

    Velde, G. van der; Platvoet, D.

    2007-01-01

    The first record of the quagga mussel Dreissena rostriformis bugensis (Andrusov, 1897) in Germany is described. This species has expanded its distribution area in Europe at a slower rate than the zebra mussel Dreissena polymorpha (Pallas, 1771). Recent records from the Danube in Romania and from an

  8. Hemocytes of zebra mussels (Dreissena polymorpha are relevant cells for the monitoring of environmental genotoxicity by the comet assay.

    Directory of Open Access Journals (Sweden)

    Marc Bonnard

    2015-06-01

    Full Text Available The measure of DNA integrity by the single cell gel electrophoresis (SCGE or comet assay is especially recommended for its sensitivity and its capacity for detecting different types of damages. Therefore, it has been applied in environmental genotoxicity in a variety of organisms. It appears today necessary to define both reference and threshold levels of DNA damage, for their application in in situ biomonitoring. However, little is known about the influence of both biological (sex, reproduction status or external (temperature… confounding factors on the measure of DNA damage by the comet assay. These variables need to be taken into account if the robustness of the assay is to be established (Jha, 2008. In the zebra mussel Dreissena polymorpha (recommended as a sentinel species in the evaluation of freshwater quality the measure of DNA damage by the comet assay is mainly performed on hemocytes, which are circulating cells involved in key physiological functions such as immunity, homeostasis, detoxication…. This communication will present and discuss results from an innovative study about the variability of the baseline level of DNA damage in hemocytes of mussels encaged for one year in the canal de l’Aisne à la Marne (Reims, according to their sex and their reproductive status. The sensitivity and the suitability of hemocytes in the evaluation of environmental genotoxicity will also be discussed, referring to observations during a 6 month-exposure of mussels in mesocosms to environmentally realistic concentrations of carbamazepine.

  9. DNA oxidation and DNA repair in gills of zebra mussels exposed to cadmium and benzo(a)pyrene.

    Science.gov (United States)

    Michel, Cécile; Vincent-Hubert, Françoise

    2015-11-01

    Freshwater bivalve molluscs are considered as effective indicators of environmental pollution. The comet assay allows the detection of DNA damage such as DNA strand breaks and alkali-labile sites. The main oxidative lesion, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), which is a pre-mutagenic lesion, can be detected by the comet assay coupled with the hOGG1 DNA repair enzyme. With this modified assay we recently observed that BaP induced 8-oxodG lesions and with the modified comet-Fpg assay we observed that Cd induced oxidative DNA damage. The aim of this study was to determine the stability of DNA lesions in Cd and BaP exposed zebra mussels using the comet-hOGG1 assay. Mussels were exposed for 24 h to these two chemicals and then placed in clean water for 6 days. We observed that BaP (7, 12 and 18 µg/L) induced an increase of DNA strand break levels as soon as 6 h of exposure and that the two highest concentrations of BaP induced a low level of hOGG1-sensitive sites. After 2 days of depuration, BaP induced DNA lesions returned to the basal level, indicating an effective DNA repair. Cd (3, 32 and 81 µg/L) induced an increase of the DNA strand break levels and a low level of hOGG1-sensitive sites. This study revealed that BaP-induced DNA lesions are repaired more efficiently than Cd-induced DNA lesions. As the level of hOGG1 sensitive sites was increased in Cd and BaP exposed mussels, it seems that these chemicals induce 8-oxo-dG.

  10. Modeling metal bioaccumulation in the invasive mussels Dreissena polymorpha and Dreissena rostriformis bugensis in the rivers Rhine and Meuse.

    Science.gov (United States)

    Le, T T Yen; Leuven, Rob S E W; Hendriks, A Jan

    2011-12-01

    The metal-specific covalent index and the species-specific size-based filtration rate were integrated into a biokinetic model estimating metal bioaccumulation in mussels from the dissolved phase and phytoplankton. The model was validated for zebra (Dreissena polymorpha) and quagga (Dreissena rostriformis bugensis) mussels in the rivers Rhine and Meuse, the Netherlands. The model performed well in predicting tissue concentrations in different-sized zebra mussels from various sampling sites for (55) Mn, (56) Fe, (59) Co, (60) Ni, (82) Se, (111) Cd, (118) Sn, and (208) Pb (r(2) =0.71-0.99). Performance for (52) Cr, (63) Cu, (66) Zn, (68) Zn, and (112) Cd was moderate (r(2) quagga mussels, approximately 73 to 94% of the variability in concentrations of (82) Se, (111) Cd, (112) Cd, and (208) Pb was explained by the model (r(2) =0.73-0.94), followed by (52) Cr, (55) Mn, (56) Fe, (60) Ni, and (63) Cu (r(2) =0.48-0.61). Additionally, in both zebra and quagga mussels, average modeled concentrations were within approximately one order of magnitude of the measured values. In particular, in zebra mussels, estimations of (60) Ni and (82) Se concentrations were equal to 51 and 76% of the measurements, respectively. Higher deviations were observed for (52) Cr, (59) Co, (55) Mn, (56) Fe, (111) Cd, (63) Cu, and (112) Cd (underestimation), and (66) Zn, (68) Zn, (208) Pb, and (118) Sn (overestimation). For quagga mussels, modeled concentrations of (66) Zn and (68) Zn differed approximately 14% from the measured levels. Differences between predictions and measurements were higher for other metals. Copyright © 2011 SETAC.

  11. Ruinous resident: the hydroid Ectopleura crocea negatively affects suspended culture of the mussel Mytilus galloprovincialis.

    Science.gov (United States)

    Fitridge, Isla; Keough, Michael J

    2013-01-01

    Hydroids are major biofouling organisms in global aquaculture. Colonies of the hydroid Ectopleura crocea have recently established in Australian commercial mussel leases culturing Mytilus galloprovincialis. This study examined the impacts of E. crocea on mussel culture at two stages of the production cycle: spatfall and grow-out. Hydroids most commonly fouled the body, edge and dorsal regions of the mussel shell and cause a reduction in the length (4%) and weight (23%) of juvenile mussels. They also consumed mussel larvae in the field and in the laboratory. Prey numbers of many taxa, including mussel larvae, were consistent in natural hydroid diets regardless of the temporal variation in prey availability, implying some selectivity in hydroid feeding. In the laboratory, E. crocea consumed settling plantigrade mussel larvae more readily than trochophore or veliger larvae. Fouling by E. crocea is detrimental to mussel condition, and may affect the availability of wild mussel larvae in the commercial culture of M. galloprovincialis.

  12. The quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) – another Ponto-Caspian dreissenid bivalve in the southern Baltic catchment: the first record from the Szczecin Lagoon

    OpenAIRE

    Adam Woźniczka; Brygida Wawrzyniak-Wydrowska; Teresa Radziejewska; Anna Skrzypacz

    2016-01-01

    In 2014, a non-indigenous dreissenid bivalve, the quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) was for the first time recorded in the Szczecin Lagoon. This was also the first record of the species in the Baltic Sea catchment. The quagga mussel was found to accompany the zebra mussel (Dreissena polymorpha), a non-indigenous bivalve already firmly established in the Lagoon. As indicated by the new immigrant's estimated abundance (4000.0 ± 355.44 ind. m−2) and the zebra mussel ...

  13. Effects of Freshwater Pollution on the Genetics of Zebra Mussels (Dreissena polymorpha at the Molecular and Population Level

    Directory of Open Access Journals (Sweden)

    Emilia G. Thomas

    2014-01-01

    Full Text Available Revealing long-term effects of contaminants on the genetic structure of organisms inhabiting polluted environments should encompass analyses at the population, molecular, and cellular level. Following this concept, we studied the genetic constitution of zebra mussel populations from a polluted (Dp and reference sites (Cl at the river Drava, Croatia, and applied microsatellite and DNA damage analyses (Comet assay, micronucleus test (MNT. Additionally, mussels from both populations were exposed to polluted wastewater in the laboratory for three days, and DNA damage was analyzed to evaluate acclimatization and genetic adaptation of the investigated populations to the polluted environment. The two populations differed in their genetic constitution. Microsatellite analysis suggested that Dp had undergone a genetic bottleneck. Comet assay did not indicate any difference in DNA damage between the two populations, but MNT revealed that Dp had an increased percentage of micronuclei in hemocytes in comparison to Cl. The laboratory experiment revealed that Dp had a lower percentage of tail DNA and a higher percentage of micronuclei than Cl. These differences between populations were possibly caused by an overall decreased fitness of Dp due to genetic drift and by an enhanced DNA repair mechanism due to acclimatization to pollution in the source habitat.

  14. Effects of freshwater pollution on the genetics of zebra mussels (Dreissena polymorpha) at the molecular and population level.

    Science.gov (United States)

    Thomas, Emilia G; Srut, Maja; Stambuk, Anamaria; Klobučar, Göran I V; Seitz, Alfred; Griebeler, Eva Maria

    2014-01-01

    Revealing long-term effects of contaminants on the genetic structure of organisms inhabiting polluted environments should encompass analyses at the population, molecular, and cellular level. Following this concept, we studied the genetic constitution of zebra mussel populations from a polluted (Dp) and reference sites (Cl) at the river Drava, Croatia, and applied microsatellite and DNA damage analyses (Comet assay, micronucleus test (MNT)). Additionally, mussels from both populations were exposed to polluted wastewater in the laboratory for three days, and DNA damage was analyzed to evaluate acclimatization and genetic adaptation of the investigated populations to the polluted environment. The two populations differed in their genetic constitution. Microsatellite analysis suggested that Dp had undergone a genetic bottleneck. Comet assay did not indicate any difference in DNA damage between the two populations, but MNT revealed that Dp had an increased percentage of micronuclei in hemocytes in comparison to Cl. The laboratory experiment revealed that Dp had a lower percentage of tail DNA and a higher percentage of micronuclei than Cl. These differences between populations were possibly caused by an overall decreased fitness of Dp due to genetic drift and by an enhanced DNA repair mechanism due to acclimatization to pollution in the source habitat.

  15. Evaluation of relocation of unionid mussels into artificial ponds

    Science.gov (United States)

    Newton, T.J.; Monroe, E.M.; Kenyon, R.; Gutreuter, S.; Welke, K.I.; Thiel, P.A.

    2001-01-01

    Relocation of unionid mussels into refuges (e.g., hatchery ponds) has been suggested as a management tool to protect these animals from the threat of zebra mussel (Dreissena polymorpha) invasion. To evaluate the efficacy of relocation, we experimentally relocated 768 mussels, representing 5 species (Leptodea fragilis, Obliquaria reflexa, Fusconaia flava, Amblema plicata, and Quadrula quadrula) into an earthen pond at a National Fish Hatchery or back into the river. In both locations, mussels were placed into 1 of 4 treatments (mesh bags, corrals, and buried or suspended substrate-filled trays). Mussels were examined annually for survival, growth (shell length and wet mass), and physiological condition (glycogen concentration in foot and mantle and tissue condition index) for 36 mo in the pond or 40 mo in the river. We observed significant differences in mortality rates between locations (mortality was 4 times greater in the pond than in the river), among treatments (lowest mortality in the suspended trays), and among species (lower mortality in the amblemines than lamp-silines). Overall survival in both locations averaged 80% the 1st year; survival in the pond decreased dramatically after that. Although length and weight varied between locations and over time, these changes were small, suggesting that their utility as short-term measures of well being in long-lived unionids is questionable. Mussels relocated to the pond were in poor physiological condition relative to those in the river, but the magnitude of these differences was small compared to the inherent variability in physiological condition of reference mussels. These data suggest that relocation of unionids into artificial ponds is a high-risk conservation strategy; alternatives such as introduction of infected host fish, identification of mussel beds at greatest risk from zebra mussels, and a critical, large-scale assessment of the factors contributing to their decline should be explored.

  16. Validated methodology for quantifying infestation levels of dreissenid mussels in environmental DNA (eDNA) samples.

    Science.gov (United States)

    Peñarrubia, Luis; Alcaraz, Carles; Vaate, Abraham Bij de; Sanz, Nuria; Pla, Carles; Vidal, Oriol; Viñas, Jordi

    2016-12-14

    The zebra mussel (Dreissena polymorpha Pallas, 1771) and the quagga mussel (D. rostriformis Deshayes, 1838) are successful invasive bivalves with substantial ecological and economic impacts in freshwater systems once they become established. Since their eradication is extremely difficult, their detection at an early stage is crucial to prevent spread. In this study, we optimized and validated a qPCR detection method based on the histone H2B gene to quantify combined infestation levels of zebra and quagga mussels in environmental DNA samples. Our results show specific dreissenid DNA present in filtered water samples for which microscopic diagnostic identification for larvae failed. Monitoring a large number of locations for invasive dreissenid species based on a highly specific environmental DNA qPCR assay may prove to be an essential tool for management and control plans focused on prevention of establishment of dreissenid mussels in new locations.

  17. Quagga mussels Dreissena rostriformis burgensis (Andrusov, 1897) in the Main River (Germany)

    OpenAIRE

    Velde, G. van der; Platvoet, D.

    2007-01-01

    The first record of the quagga mussel Dreissena rostriformis bugensis (Andrusov, 1897) in Germany is described. This species has expanded its distribution area in Europe at a slower rate than the zebra mussel Dreissena polymorpha (Pallas, 1771). Recent records from the Danube in Romania and from an enclosed Rhine-Meuse estuary in The Netherlands, suggest that the Main-Danube canal and River Rhine have functioned as the dispersal pathway of the quagga mussel to The Netherlands. The record of t...

  18. Changes in lipid content and fatty acid composition along the reproductive cycle of the freshwater mussel Dreissena polymorpha: Its modulation by clofibrate exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lazzara, Raimondo; Fernandes, Denise, E-mail: deniseferna@gmail.com; Faria, Melissa; Lopez, Jordi F.; Tauler, Roma; Porte, Cinta, E-mail: cinta.porte@cid.csic.es

    2012-08-15

    Total lipids and fatty acid profiles were determined along the reproductive cycle of the zebra mussel (Dreissena polymorpha). A total of 33 fatty acids with carbon atoms from 14 to 22 were identified: palmitic acid (16:0) was the most abundant fatty acid (13-24%) followed by docosahexaenoic acid (DHA; 22:6n-3), eicosapentaenoic acid (EPA; 20:5n-3) and palmitoleic acid (16:1n-7). Some individual fatty acids (16:0, 16:2n-4, 18:1n-7, 18:2n-6, 18:3n-4, 18:4n-3, 20:4n-3, 20:5n-3) were strongly related to reproductive events, while others having structural-type functions (18:0 and 22:6n-3) were rather stable during the study period. Multivariate analysis of the whole data set using the multivariate curve resolution alternating least squares method confirmed the strong relationship of fatty acid profiles with the reproductive cycle of zebra mussel. Additionally, the effects of the pharmaceutical clofibrate on lipid composition and fatty acid profiles were assessed following 7-day exposure of zebra mussels to a wide range of concentrations (20 ng/L to 2 mg/L). A significant reduction in total triglycerides (38%-48%) together with an increase in the amount of fatty acids per gram wet weight (1.5- to 2.2-fold) was observed in the exposed mussels. This work highlights the ability of clofibrate to induce changes on the lipidome of zebra mussels at concentrations as low as 200 ng/L. -- Highlights: Black-Right-Pointing-Pointer Clofibrate exposure leads to a reduction of total triglycerides in zebra mussel. Black-Right-Pointing-Pointer The amount of fatty acids per gram wet weight increased in exposed mussels. Black-Right-Pointing-Pointer The effects were evidenced at concentrations of clofibrate as low as 200 ng/L. Black-Right-Pointing-Pointer Fatty acid profiles were closely related to reproductive events.

  19. Changes in lipid content and fatty acid composition along the reproductive cycle of the freshwater mussel Dreissena polymorpha: Its modulation by clofibrate exposure

    International Nuclear Information System (INIS)

    Lazzara, Raimondo; Fernandes, Denise; Faria, Melissa; López, Jordi F.; Tauler, Romà; Porte, Cinta

    2012-01-01

    Total lipids and fatty acid profiles were determined along the reproductive cycle of the zebra mussel (Dreissena polymorpha). A total of 33 fatty acids with carbon atoms from 14 to 22 were identified: palmitic acid (16:0) was the most abundant fatty acid (13–24%) followed by docosahexaenoic acid (DHA; 22:6n−3), eicosapentaenoic acid (EPA; 20:5n−3) and palmitoleic acid (16:1n−7). Some individual fatty acids (16:0, 16:2n−4, 18:1n−7, 18:2n−6, 18:3n−4, 18:4n−3, 20:4n−3, 20:5n−3) were strongly related to reproductive events, while others having structural-type functions (18:0 and 22:6n−3) were rather stable during the study period. Multivariate analysis of the whole data set using the multivariate curve resolution alternating least squares method confirmed the strong relationship of fatty acid profiles with the reproductive cycle of zebra mussel. Additionally, the effects of the pharmaceutical clofibrate on lipid composition and fatty acid profiles were assessed following 7-day exposure of zebra mussels to a wide range of concentrations (20 ng/L to 2 mg/L). A significant reduction in total triglycerides (38%–48%) together with an increase in the amount of fatty acids per gram wet weight (1.5- to 2.2-fold) was observed in the exposed mussels. This work highlights the ability of clofibrate to induce changes on the lipidome of zebra mussels at concentrations as low as 200 ng/L. -- Highlights: ► Clofibrate exposure leads to a reduction of total triglycerides in zebra mussel. ► The amount of fatty acids per gram wet weight increased in exposed mussels. ► The effects were evidenced at concentrations of clofibrate as low as 200 ng/L. ► Fatty acid profiles were closely related to reproductive events.

  20. Lysosomal responses in the digestive gland of the freshwater mussel, Dreissena polymorpha, experimentally exposed to cadmium

    International Nuclear Information System (INIS)

    Giamberini, Laure; Cajaraville, Miren P.

    2005-01-01

    In order to examine the possible use of lysosomal response as a biomarker of freshwater quality, structural changes of lysosomes were measured by image analysis in the digestive gland of the zebra mussel, Dreissena polymorpha, exposed in laboratory conditions to cadmium. Mussels were exposed to the metal (10 and 200 μg/L) for 3 weeks and randomly collected after 7 and 21 days. At each treatment day, digestive tissues were excised and β-glucuronidase activity was revealed in cryotome sections. Four stereological parameters were calculated: lysosomal volume density, lysosomal surface density, lysosomal surface to volume ratio, and lysosomal numerical density. The changes observed in this study reflected a general activation of the lysosomal system, including an increase in both the number and the size of lysosomes in the digestive gland cells of mussels exposed to cadmium. The digestive lysosomal response in zebra mussels was related to exposure time and to metal concentration, demonstrating the potential of this biomarker in freshwater biomonitoring

  1. ANALYSIS OF MATERIALS IN AN EXPERIMENTAL TESTING PIPE SYSTEM FOR AN INHIBITOR OF MUSSEL KILL

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2003-06-04

    A comprehensive series of 16 laboratory experiments demonstrated that the presence of vinyl tubing within a recirculating pipe system was responsible for lowering zebra mussel kill following treatment with the bacterium Pseudomonas fluorescens. All vinyl tubing was replaced in all testing units with silicone tubing, and high mussel kill (>95%) was then obtained.

  2. Mussel dynamics model: A hydroinformatics tool for analyzing the effects of different stressors on the dynamics of freshwater mussel communities

    Science.gov (United States)

    Morales, Y.; Weber, L.J.; Mynett, A.E.; Newton, T.J.

    2006-01-01

    A model for simulating freshwater mussel population dynamics is presented. The model is a hydroinformatics tool that integrates principles from ecology, river hydraulics, fluid mechanics and sediment transport, and applies the individual-based modelling approach for simulating population dynamics. The general model layout, data requirements, and steps of the simulation process are discussed. As an illustration, simulation results from an application in a 10 km reach of the Upper Mississippi River are presented. The model was used to investigate the spatial distribution of mussels and the effects of food competition in native unionid mussel communities, and communities infested by Dreissena polymorpha, the zebra mussel. Simulation results were found to be realistic and coincided with data obtained from the literature. These results indicate that the model can be a useful tool for assessing the potential effects of different stressors on long-term population dynamics, and consequently, may improve the current understanding of cause and effect relationships in freshwater mussel communities. ?? 2006 Elsevier B.V. All rights reserved.

  3. Cumulative effects of ibuprofen and air emersion in zebra mussels Dreissena polymorpha.

    Science.gov (United States)

    André, C; Gagné, F

    2017-10-01

    Municipal effluents are major source of pharmaceutical products in the environment. The purpose of this study was to examine the toxicity of a largely used drug, ibuprofen (Ibu), in Dresseina polymorpha mussels and its impact on air survival time. The mussels were exposed to increasing concentration of Ibu (0, 1, 10 and 100μg/L) for 96 at 15°C and a sub-group of mussels was maintain in air for another 96h. Post-exposure mussels (Ibu and Ibu+Air) were analyzed for weight loss, total triglycerides, neutral lipids, lipid peroxidation (LPO), arachidonate-dependent cyclooxygenase (COX) and glutathione S-transferase activity. Lipid extracts of mussel tissues were also analyzed by 1 H-nuclear resonance spectroscopy. The data revealed that mussels exposed to Ibu had increased signs of lipid oxidation, neutral lipids and decreased triglycerides, LPO and GST activity. COX activity was significantly reduced by Ibu in keeping with mode of action of the drug. Following exposure to air, increased weight loss, neutral lipids (lipid degradation), were observed in mussels exposed to Ibu but no changes in COX activity were observed. Air stress limited the decrease in triglycerides and the increase in GST in mussels exposed to 100μg/L Ibu indicating decreased anti-oxidant response/phase II biotransformation and limited lipid metabolism. In conclusion, exposure to Ibu has some anti-inflammatory effects to mussels based on COX activity but resulted in increased oxidative damage and lipid catabolism. Exposure to air stress could enhance some of these responses and contribute to decreased resistance to air exposures. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  4. The Quagga mussel invades the Lake Superior basin - journal article

    Science.gov (United States)

    Prior studies recognized the presence of a single dreissenid species in Lake Superior--the zebra mussel Dreissena polymorpha. However, taxonomic keys based on traditional shell morphology are not always able to differentiate dreissenid species with confidence. We thus employed ge...

  5. Optically and biologically active mussel protein-coated double-walled carbon nanotubes.

    Science.gov (United States)

    Jung, Yong Chae; Muramatsu, Hiroyuki; Fujisawa, Kazunori; Kim, Jin Hee; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S

    2011-12-02

    A method of dispersing strongly bundled double-walled carbon nanotubes (DWNTs) via a homogeneous coating of mussel protein in an aqueous solution is presented. Optical activity, mechanical strength, as well as electrical conductivity coming from the nanotubes and the versatile biological activity from the mussel protein make mussel-coated DWNTs promising as a multifunctional scaffold and for anti-fouling materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Trophic structure of the fouling community in Odessa Bay (Black Sea

    Directory of Open Access Journals (Sweden)

    A. Y. Varigin

    2016-06-01

    Full Text Available The trophic structure of the coastal fouling community of Odessa Bay (Black Sea, which was composed of 10 species of macrophytes, 57 invertebrate species and 4 species of fish, was determined. The basic trophic relationship between organisms composing the community is shown. A minimization of interspecific trophic competition within the community is noted. The main sources of food material entering the fouling community were determined. We show that a significant proportion of food in the form of detritus, dissolved organic matter and small planktonic organisms enters the community from the water column. Filtration and pumping activity of sestonophage-organisms, particularly mussels, helps to attract food material to the community. Primary producers of the community are macrophytes and microphytes, which develop on account of their photosynthetic activity and ensure the provision of food to herbivores. The trophic group of detritophages consumes different fractions of the detritus which accumulates in the byssus threads of bivalve molluscs. In this context, mussel druses act as sediment traps, collecting detritus. Numerous polyphages, which are essentially omnivores and do not usually lack food material, were noted in the community. A small group of carnivorous invertebrates, whose representatives actively attack small animals, was identified. The abundance of these species in the community was about 1%, and their biomass less than 0.6%. Fish living in macrophyte weeds are the consumers in the community. We determined that the highest relative abundance (over 36% in the fouling community was reached by sestonophages and polyphages. We found that the undisputed leader in the relative biomass (over 97% in the fouling community ofOdessaBaywas the sestonophages (mainly composed of mussels. We determined that the trophic structure index of the community was 0.94, which confirms the significant dominance in biomass of bivalves over other species in

  7. Developmental plasticity of shell morphology of quagga mussels from shallow and deep-water habitats of the Great Lakes.

    Science.gov (United States)

    Peyer, Suzanne M; Hermanson, John C; Lee, Carol Eunmi

    2010-08-01

    The invasive zebra mussel (Dreissena polymorpha) has quickly colonized shallow-water habitats in the North American Great Lakes since the 1980s but the quagga mussel (Dreissena bugensis) is becoming dominant in both shallow and deep-water habitats. While quagga mussel shell morphology differs between shallow and deep habitats, functional causes and consequences of such difference are unknown. We examined whether quagga mussel shell morphology could be induced by three environmental variables through developmental plasticity. We predicted that shallow-water conditions (high temperature, food quantity, water motion) would yield a morphotype typical of wild quagga mussels from shallow habitats, while deep-water conditions (low temperature, food quantity, water motion) would yield a morphotype present in deep habitats. We tested this prediction by examining shell morphology and growth rate of quagga mussels collected from shallow and deep habitats and reared under common-garden treatments that manipulated the three variables. Shell morphology was quantified using the polar moment of inertia. Of the variables tested, temperature had the greatest effect on shell morphology. Higher temperature (approximately 18-20 degrees C) yielded a morphotype typical of wild shallow mussels regardless of the levels of food quantity or water motion. In contrast, lower temperature (approximately 6-8 degrees C) yielded a morphotype approaching that of wild deep mussels. If shell morphology has functional consequences in particular habitats, a plastic response might confer quagga mussels with a greater ability than zebra mussels to colonize a wider range of habitats within the Great Lakes.

  8. IMPACT OF FIVE TREATMENT FACTORS ON MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2003-12-08

    Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify factors that affect mussel kill. Test results reported herein indicate that mussel kill should not be affected by: (1) air bubbles being carried by currents through power plant pipes; (2) pipe orientation (e.g., vertical or horizontal); (3) whether the bacterial cell concentration during a treatment is constant or slightly varying; (4) whether a treatment is between 3 hr and 12 hr in duration, given that the total quantity of bacteria being applied to the pipe is a constant; and (5) whether the water temperature is between 13 C and 23 C.

  9. Concentrations of 17 elements in the zebra mussel (Dreissena polymorpha), in different tissues of perch (Perca fluviatilis), and in perch intestinal parasites (Acanthocephalus lucii) from the subalpine lake Mondsee, Austria

    Energy Technology Data Exchange (ETDEWEB)

    Sures, B.; Steiner, W.; Rydlo, M.; Taraschewski, H.

    1999-11-01

    Concentrations of the elements Al, Ag, Ba, ca, Cd, Co, Cr, cu, Fe, Ga, Mg, Mn, Ni, Pb, Sr, Tl, and Zn were analyzed by inductively coupled plasma mass spectrometry in the acanthocephalan Acanthocephalus lucii (Mueller); in its host, Perca fluviatilis (L.), and in the soft tissue of the zebra mussel, Dreissena polymorpha (Pallas). All animals were collected from the same sampling site in a subalpine lake, Mondsee, in Austria. Most of the elements were found at significantly higher concentrations in the acanthocephalan than in different tissues (muscle, liver, and intestinal wall) of its perch host. Only Co was concentrated in the liver of perch to a level that was significantly higher than that found in the parasite. Most of the analyzed elements were also present at significantly higher concentrations in A. lucii than in D. polymorpha. Barium and Cr were the only elements recorded at higher concentrations in the mussel compared with the acanthocephalan. Thus, when comparing the accumulation of elements, the acanthocephalans appear to be even more suitable than the zebra mussels in terms of their use in the detection of metal contamination within aquatic biotopes. Spearman correlation analysis revealed that the concentrations of several elements within the parasites decreased with increasing infrapopulation. Furthermore, the levels of some elements in the perch liver were negatively correlated with the weight of A. lucii in the intestine. Thus, it emerged that not only is there competition for elements between acanthocephalans inside the gut but there is also competition for these elements between the host and the parasites. The elevated element concentrations demonstrated here in the parasitic worm A. lucii provide support for further investigations of these common helminthes and of their accumulation properties.

  10. Cellular energy allocation in zebra mussels exposed along a pollution gradient: linking cellular effects to higher levels of biological organization.

    Science.gov (United States)

    Smolders, R; Bervoets, L; De Coen, W; Blust, R

    2004-05-01

    Organisms exposed to suboptimal environments incur a cost of dealing with stress in terms of metabolic resources. The total amount of energy available for maintenance, growth and reproduction, based on the biochemical analysis of the energy budget, may provide a sensitive measure of stress in an organism. While the concept is clear, linking cellular or biochemical responses to the individual and population or community level remains difficult. The aim of this study was to validate, under field conditions, using cellular energy budgets [i.e. changes in glycogen-, lipid- and protein-content and mitochondrial electron transport system (ETS)] as an ecologically relevant measurement of stress by comparing these responses to physiological and organismal endpoints. Therefore, a 28-day in situ bioassay with zebra mussels (Dreissena polymorpha) was performed in an effluent-dominated stream. Five locations were selected along the pollution gradient and compared with a nearby (reference) site. Cellular Energy Allocation (CEA) served as a biomarker of cellular energetics, while Scope for Growth (SFG) indicated effects on a physiological level and Tissue Condition Index and wet tissue weight/dry tissue weight ratio were used as endpoints of organismal effects. Results indicated that energy budgets at a cellular level of biological organization provided the fastest and most sensitive response and energy budgets are a relevant currency to extrapolate cellular effects to higher levels of biological organization within the exposed mussels.

  11. Structural-based differences in ecotoxicity of benzoquinoline isomers to the zebra mussel (Dreissena polymorpha)

    Energy Technology Data Exchange (ETDEWEB)

    Kraak, M.H.S.; Wijnands, P.; Govers, H.A.J.; Admiraal, W.; Voogt, P. de [Univ. of Amsterdam (Netherlands)

    1997-10-01

    Effects of four benzoquinoline isomers on the filtration rate of the zebra mussel (Dreissena polymorpha) were analyzed, to study the effect of minor differences in chemical structure on adverse biological effects. Filtration rates were measured after 48 h of exposure to different concentrations of acridine, phenanthridine, benzo[f]quinoline, and benzo[h]quinoline in the water. The 50% effective concentration (EC50) values for filtration rate of the four isomers differed significantly. Effects increased in the order benzo[f], -[h], -[b], and -[c]quinoline, and the difference between the most toxic isomer and the least toxic isomer amounted to a factor of 30. Attempts were made to relate these differences in toxicity to the structure of the isomers. Size- or topology-related molecular descriptors provided insufficient resolution to distinguish between the benzoquinoline isomers, and none of the electronic descriptors separately provided a significant correlation with the observed effects. In an alternative approach, molecular shape, accessibility, and minimum agent-macromolecule distance were used to represent repulsive and attractive forces between the benzoquinoline isomers and biological membranes. This approach could tentatively explain the observed effects and is supported by a high correlation between the EC50 data and the reversed-phase C18-HPLC behavior of the benzoquinolines (k{sub 0}), which is likely to be governed by similar processes.

  12. Metallothionein mRNA induction is correlated with the decrease of DNA strand breaks in cadmium exposed zebra mussels.

    Science.gov (United States)

    Vincent-Hubert, Françoise; Châtel, Amélie; Gourlay-Francé, Catherine

    2014-05-15

    We have previously shown that cadmium (Cd) and benzo[a]pyrene (BaP) induced early DNA damages in zebra mussels, and that the level of DNA strand breaks (SB) returned to a basal level after 3 days of exposure to Cd. The aim of the present study was to go further in the mechanisms of Cd and BaP detoxification. For that purpose, expression of genes encoding for metallothionein (MT), aryl hydrocarbon receptor (AHR), P-gp, catalase, glutathione S-transferase and heat shock protein 70 (HSP70) proteins have been measured using RT-qPCR. Data reported here show that Cd is a strong inducer of MT and HSP70 genes, and that BaP is a strong inducer of P-gp and AHR genes. Exposure to Cd and BaP resulted in moderate changes in antioxidant enzymes mRNA. Since the increase of MT mRNA occurred when the DNA SB level returned to its basal level, we can suggest that MT is implicated in cadmium detoxification. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. A comparative study of byssogenesis on zebra and quagga mussels: the effects of water temperature, salinity and light-dark cycle.

    Science.gov (United States)

    Grutters, Bart M C; Verhofstad, Michiel J J M; van der Velde, Gerard; Rajagopal, Sanjeevi; Leuven, Rob S E W

    2012-01-01

    The quagga mussel (Dreissena rostriformis bugensis) and zebra mussel (Dreissena polymorpha) are invasive freshwater bivalves in Europe and North America. The distribution range of both Dreissena species is still expanding and both species cause major biofouling and ecological effects, in particular when they invade new areas. In order to assess the effect of temperature, salinity and light on the initial byssogenesis of both species, 24 h re-attachment experiments in standing water were conducted. At a water temperature of 25°C and a salinity of 0.2 psu, the rate of byssogenesis of D. polymorpha was significantly higher than that of D. rostriformis bugensis. In addition, byssal thread production by the latter levelled out between 15°C and 25°C. The rate of byssogenesis at temperatures<25°C was similar for both species. Neither species produced any byssal threads at salinities of 4 psu or higher. At a salinity of 1 psu and a water temperature of 15°C, D. polymorpha produced significantly more byssal threads than D. rostriformis bugensis. There was no significant effect of the length of illumination on the byssogenesis of either species. Overall, D. polymorpha produced slightly more byssal threads than D. rostriformis bugensis at almost all experimental conditions in 24 h re-attachment experiments, but both species had essentially similar initial re-attachment abilities. The data imply that D. rostriformis bugensis causes biofouling problems identical to those of D. polymorpha.

  14. Induction of heat shock proteins (hsp70) in the zebra mussel (Dreissena polymorpha) following exposure to platinum group metals (platinum, palladium and rhodium): Comparison with lead and cadmium exposures

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Christoph [Zoologisches Institut I-Oekologie, Universitaet Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D-76131 Karlsruhe (Germany); Zimmermann, Sonja [Zoologisches Institut I-Oekologie, Universitaet Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D-76131 Karlsruhe (Germany); Sures, Bernd [Zoologisches Institut I-Oekologie, Universitaet Karlsruhe, Geb. 07.01, Kornblumenstrasse 13, D-76131 Karlsruhe (Germany)]. E-mail: dc11@rz.uni-karlsruhe.de

    2005-10-05

    An increasing number of papers concentrate on the availability and uptake of platinum group elements (PGE) by different organisms. These metals are discharged into the environment from different anthropogenic sources, such as automobile catalytic converters, hospitals and other medical institutions. As the effects of these precious metals on organisms remain unclear, the induction of heat shock proteins (hsp70) in zebra mussels (Dreissena polymorpha) following exposure to soluble salts of platinum, palladium and rhodium was compared with the hsp70 induction in mussels following exposure to cadmium and lead. Mussels were sampled weekly during a period of 10 weeks and analyzed for their metal concentration and their hsp70 level. Highest metal uptake was found for Cd, followed by Pt, Pb and Pd. Rh demonstrated the lowest uptake rate. A clear time-dependent increase of hsp70 levels occurred in all exposed mussels. Concentrations of hsp70 started to rise between days 18 and 25, except for the Pt-exposed group, where the initial increase was between days 25 and 32. All groups reached maximal hsp70 concentrations at day 39. Subsequently, hsp70 levels decreased to initial levels for the remaining exposure period. Threshold metal levels for the hsp70 induction varied among the metals and increased in the order: Rh < Pd {<=} Pb < Pt < Cd. Highest hsp70 values were found for mussels exposed to Pd, with a 25-fold higher level than in the controls, followed by Pt- and Rh-exposed mussels, which showed a 19-fold increase. The hsp70 levels of the mussels exposed to Cd and Pb were much lower, showing 6- and 12-fold higher values than the control, respectively. The clear induction of hsp70 due to exposure to Pt, Pd and Rh gives evidence for strong cellular effects of these metals, especially, when compared with lead and cadmium. Among the metals tested, Pd seems to have the highest potential as inducer for hsp70 production due to its low threshold level in combination with the

  15. Induction of heat shock proteins (hsp70) in the zebra mussel (Dreissena polymorpha) following exposure to platinum group metals (platinum, palladium and rhodium): Comparison with lead and cadmium exposures

    International Nuclear Information System (INIS)

    Singer, Christoph; Zimmermann, Sonja; Sures, Bernd

    2005-01-01

    An increasing number of papers concentrate on the availability and uptake of platinum group elements (PGE) by different organisms. These metals are discharged into the environment from different anthropogenic sources, such as automobile catalytic converters, hospitals and other medical institutions. As the effects of these precious metals on organisms remain unclear, the induction of heat shock proteins (hsp70) in zebra mussels (Dreissena polymorpha) following exposure to soluble salts of platinum, palladium and rhodium was compared with the hsp70 induction in mussels following exposure to cadmium and lead. Mussels were sampled weekly during a period of 10 weeks and analyzed for their metal concentration and their hsp70 level. Highest metal uptake was found for Cd, followed by Pt, Pb and Pd. Rh demonstrated the lowest uptake rate. A clear time-dependent increase of hsp70 levels occurred in all exposed mussels. Concentrations of hsp70 started to rise between days 18 and 25, except for the Pt-exposed group, where the initial increase was between days 25 and 32. All groups reached maximal hsp70 concentrations at day 39. Subsequently, hsp70 levels decreased to initial levels for the remaining exposure period. Threshold metal levels for the hsp70 induction varied among the metals and increased in the order: Rh < Pd ≤ Pb < Pt < Cd. Highest hsp70 values were found for mussels exposed to Pd, with a 25-fold higher level than in the controls, followed by Pt- and Rh-exposed mussels, which showed a 19-fold increase. The hsp70 levels of the mussels exposed to Cd and Pb were much lower, showing 6- and 12-fold higher values than the control, respectively. The clear induction of hsp70 due to exposure to Pt, Pd and Rh gives evidence for strong cellular effects of these metals, especially, when compared with lead and cadmium. Among the metals tested, Pd seems to have the highest potential as inducer for hsp70 production due to its low threshold level in combination with the

  16. Towards a better understanding of biomarker response in field survey: a case study in eight populations of zebra mussels.

    Science.gov (United States)

    Pain-Devin, S; Cossu-Leguille, C; Geffard, A; Giambérini, L; Jouenne, T; Minguez, L; Naudin, B; Parant, M; Rodius, F; Rousselle, P; Tarnowska, K; Daguin-Thiébaut, C; Viard, F; Devin, S

    2014-10-01

    In order to provide reliable information about responsiveness of biomarkers during environmental monitoring, there is a need to improve the understanding of inter-population differences. The present study focused on eight populations of zebra mussels and aimed to describe how variable are biomarkers in different sampling locations. Biomarkers were investigated and summarised through the Integrated Biomarker Response (IBR index). Inter-site differences in IBR index were analysed through comparisons with morphological data, proteomic profiles and genetic background of the studied populations. We found that the IBR index was a good tool to inform about the status of sites. It revealed higher stress in more polluted sites than in cleaner ones. It was neither correlated to proteomic profiles nor to genetic background, suggesting a stronger influence of environment than genes. Meanwhile, morphological traits were related to both environment and genetic background influence. Together these results attest the benefit of using biological tools to better illustrate the status of a population and highlight the need of consider inter-population difference in their baselines. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Polymethylene-interrupted fatty acids: Biomarkers for native and exotic mussels in the Laurentian Great Lakes

    Science.gov (United States)

    Mezek, Tadej; Sverko, Ed; Ruddy, Martina D.; Zaruk, Donna; Capretta, Alfredo; Hebert, Craig E.; Fisk, Aaron T.; McGoldrick, Daryl J.; Newton, Teresa J.; Sutton, Trent M.; Koops, Marten A.; Muir, Andrew M.; Johnson, Timothy B.; Ebener, Mark P.; Arts, Michael T.

    2011-01-01

    Freshwater organisms synthesize a wide variety of fatty acids (FAs); however, the ability to synthesize and/or subsequently modify a particular FA is not universal, making it possible to use certain FAs as biomarkers. Herein we document the occurrence of unusual FAs (polymethylene-interrupted fatty acids; PMI-FAs) in select freshwater organisms in the Laurentian Great Lakes. We did not detect PMI-FAs in: (a) natural seston from Lake Erie and Hamilton Harbor (Lake Ontario), (b) various species of laboratory-cultured algae including a green alga (Scenedesmus obliquus), two cyanobacteria (Aphanizomenon flos-aquae and Synechococystis sp.), two diatoms (Asterionella formosa, Diatoma elongatum) and a chrysophyte (Dinobryon cylindricum) or, (c) zooplankton (Daphnia spp., calanoid or cyclopoid copepods) from Lake Ontario, suggesting that PMI-FAs are not substantively incorporated into consumers at the phytoplankton–zooplankton interface. However, these unusual FAs comprised 4-6% of total fatty acids (on a dry tissue weight basis) of native fat mucket (Lampsilis siliquoidea) and plain pocketbook (L. cardium) mussels and in invasive zebra (Dreissena polymorpha) and quagga (D. bugensis) mussels. We were able to clearly partition Great Lakes' mussels into three separate groups (zebra, quagga, and native mussels) based solely on their PMI-FA profiles. We also provide evidence for the trophic transfer of PMI-FAs from mussels to various fishes in Lakes Ontario and Michigan, further underlining the potential usefulness of PMI-FAs for tracking the dietary contribution of mollusks in food web and contaminant-fate studies.

  18. Exposure-related effects of formulated Pseudomonas fluorescens strain CL145A to glochidia from seven unionid mussel species

    Science.gov (United States)

    Luoma, James A.; Weber, Kerry L.; Severson, Todd J.; Schreier, Theresa M.; Mayer, Denise A.; Aloisi, Douglas B.; Eckert, Nathan L.

    2015-01-01

    The study was completed to evaluate the exposure-related effects of a biopesticide for dreissenid mussel (Dreissena polymorpha, zebra mussel and Dreissena rostriformis bugensis, quagga mussel) control on glochidia from unionid mussels endemic to the Great Lakes and Upper Mississippi River Basins. The commercially prepared biopesticide was either a spray-dried powder (SDP) or freeze-dried powder (FDP) formulation of Pseudomonas fluorescens, strain CL145A. Glochidia of the unionid mussel species Lampsilis cardium, Lampsilis siliquoidea,Lampsilis higginsii, Ligumia recta, Obovaria olivaria, and Actinonaias ligamentina were exposed to SDP-formulated P. fluorescens andLampsilis cardium and Megalonaias nervosa were exposed to FDP-formulated P. fluorescens.

  19. Validated methodology for quantifying infestation levels of dreissenid mussels in environmental DNA (eDNA) samples

    OpenAIRE

    Peñarrubia Lozano, Luis; Alcaraz Cazorla, Carles; Vaate, Abraham bij de; Sanz Ball-llosera, Núria; Pla Zanuy, Carles; Vidal Fàbrega, Oriol; Viñas de Puig, Jordi

    2016-01-01

    The zebra mussel (Dreissena polymorpha Pallas, 1771) and the quagga mussel (D. rostriformis Deshayes, 1838) are successful invasive bivalves with substantial ecological and economic impacts in freshwater systems once they become established. Since their eradication is extremely difficult, their detection at an early stage is crucial to prevent spread. In this study, we optimized and validated a qPCR detection method based on the histone H2B gene to quantify combined infestation levels of zebr...

  20. Quagga and Zebra Mussel Eradication and Control Tactics

    OpenAIRE

    Culver, Carolynn; Lahr, Heather; Johnson, Leigh; Cassell, Jodi

    2013-01-01

    Aquatic invasive species (AIS)continue to threaten coastal and marine habitats in California. The goal of this project is to conduct research and develop outreach materials that help agencies, groups and individuals prevent, eradication and control AIS. Current objectives include: 1) investigate recruitment dynamics of quagga mussels in southern California to provide baseline informaiton on infestations in various locations, inform monitoring efforts and to identify factors influencing the su...

  1. Control of modiolid mussels in cooling water systems by continuous chlorination.

    NARCIS (Netherlands)

    Rajagopal, S.; Venugopalan, V.P.; Velde, G. van der; Jenner, H.A.

    2006-01-01

    Abstract. Modiolid mussels such as Modiolus philippinarum and Modiolus metcalfei constitute a numerically significant group in fouling communities, especially in tropical and subtropical industrial cooling water systems. Nevertheless, there are hardly any published reports on the tolerance of these

  2. Study of Capability of Zebra Mussel (Dreissena polymorpha in Nitrate and Phosphate Indirect Removal from Urban Wastewater

    Directory of Open Access Journals (Sweden)

    Leyli Gholamhosseini

    2007-03-01

    Full Text Available Zebra mussel (Dreissenidae polymorpha is capable of filtering great volumes of water due to its high population density. In this study, Nitrate and Phosphate removal capability of 3 shell masses (20, 40, and 60 gr in urban wastewater was investigated based on filtering rate measurements (using simultaneous phytoplankton, chlorella, and Scenedesmus cultures and indirect absorption of nitrate and phosphate in open and closed systems with 3 to 10 replications. Open and closed systems showed a positive correlation between shell weights and Nitrate and Phosphate filtration rates (R2 =0.99 but a negative correlation between influent Nitrate and Phosphate concentrations and their filtration rates (R2=0.97. Increasing of shell weights in the open system resulted in absorption rates of 0.08-0.2mg.l-1 of the shell dry weight for Nitrate and 0.02-0.04 mg.l-1 for Phosphate. In the closed system, these rates were 0.03-0.11 mg.l-1 of the shell dry weight for Nitrate absorption and 0.01-0.02 mg.l-1 for Phosphate. These results show that shell masses have a low nitrate and phosphate removal efficiency, especially in the case of phosphate, and they can not be, therefore, recommended for urban wastewater treatment.

  3. The Effects of Zebra Mussels on Nitrogen Cycling and Sediment Physiochemical Characteristics: A Laboratory Experiment.

    Science.gov (United States)

    Bruesewitz, D. A.; Tank, J. L.; Bernot, M. J.

    2005-05-01

    Many ecosystems experiencing anthropogenic nitrogen loading have also been invaded by zebra mussels (ZM), therefore it is important to understand how these human-induced changes interact. In particular, ZM may impact biogeochemical transformations. We hypothesized that high NH4+ waste from ZM will increase sediment nitrification rates, and increase NO3--N available for denitrification. To test this prediction, aquaria were stocked with either no ZM or 10,000 individuals m-2. Sediment nitrification (via nitrapyrin-inhibition technique), denitrification (via chloramphenicol-amended acetylene block technique), and sediment O2 profiles (using microelectrodes) were measured weekly for 1 month. The presence of ZM increased nitrification and denitrification rates over initial conditions throughout all weeks (RM ANOVA, p<0.05). Sediment nitrification in the ZM aquaria increased to 47 ± 2.1 μ g NH4+ -NgAFDM-1h-1 by the 3rd week in comparison to 24 ± 4.4 μ g NH4+ -NgAFDM-1h-1 in control aquaria. Sediment denitrification peaked at week 2 in the ZM aquaria at 330 ± 24 μ g N2O gAFDM-1h-1 but remained low in control aquaria throughout. There was a stronger correlation between nitrification and denitrification rates in the presence of ZM (R=0.32, 0.12 respectively). These results, in addition to more frequent hypoxia in sediment oxygen profiles, suggest closer coupling between nitrification and denitrification when ZM are present.

  4. Alien parasitic copepods in mussels and oysters of the Wadden Sea

    NARCIS (Netherlands)

    Elsner, N.O.; Jacobsen, S.; Thieltges, D.W.; Reise, K.

    2011-01-01

    Molluscan intestinal parasites of the genus Mytilicola, specifically M. intestinalis, were initially introduced into bivalves in the North Sea in the 1930s. It was presumably introduced from the Mediterranean with ship-fouling mussels, then attained epidemic proportions in Mytilus edulis in the

  5. Dreissenid mussels from the Great Lakes contain elevated thiaminase activity

    Science.gov (United States)

    Tillitt, D.E.; Riley, S.C.; Evans, A.N.; Nichols, S.J.; Zajicek, J.L.; Rinchard, J.; Richter, C.A.; Krueger, C.C.

    2009-01-01

    We examined thiaminase activity in dreissenid mussels collected at different depths and seasons, and from various locations in Lakes Michigan, Ontario, and Huron. Here we present evidence that two dreissenid mussel species (Dreissena bugensis and D. polymorpha) contain thiaminase activity that is 5-100 fold greater than observed in Great Lakes fishes. Thiaminase activity in zebra mussels ranged from 10,600 to 47,900??pmol g- 1??min- 1 and activities in quagga mussels ranged from 19,500 to 223,800??pmol g- 1??min- 1. Activity in the mussels was greatest in spring, less in summer, and least in fall. Additionally, we observed greater thiaminase activity in dreissenid mussels collected at shallow depths compared to mussels collected at deeper depths. Dreissenids constitute a significant and previously unknown pool of thiaminase in the Great Lakes food web compared to other known sources of this thiamine (vitamin B1)-degrading enzyme. Thiaminase in forage fish of the Great Lakes has been causally linked to thiamine deficiency in salmonines. We currently do not know whether linkages exist between thiaminase activities observed in dreissenids and the thiaminase activities in higher trophic levels of the Great Lakes food web. However, the extreme thiaminase activities observed in dreissenids from the Great Lakes may represent a serious unanticipated negative effect of these exotic species on Great Lakes ecosystems.

  6. Evaluation of freshwater mussel relocation as a conservation and management strategy

    Science.gov (United States)

    Cope, W. Gregory; Waller, Diane L.

    1995-01-01

    The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.

  7. Efficacy and Ecotoxicity of Novel Anti-Fouling Nanomaterials in Target and Non-Target Marine Species.

    Science.gov (United States)

    Avelelas, Francisco; Martins, Roberto; Oliveira, Tânia; Maia, Frederico; Malheiro, Eliana; Soares, Amadeu M V M; Loureiro, Susana; Tedim, João

    2017-04-01

    Biofouling is a global problem that affects virtually all the immersed structures. Currently, several novel environmentally friendly approaches are being tested worldwide to decrease the toxicity of biocides in non-fouling species, such as the encapsulation/immobilization of commercially available biocides, in order to achieve control over the leaching rate. The present study addresses the toxicity of two widely used booster biocides, zinc pyrithione (ZnPT) and copper pyrithione (CuPT), in its free and incorporated forms in order to assess their toxicity and anti-fouling efficacy in target and non-target species. To achieve this goal, the following marine organisms were tested; the green microalgae Tetraselmis chuii (non-target species) and both target species, the diatom Phaeodactylum tricornutum and the mussel Mytilus edulis. Organisms were exposed to both biocides, two unloaded nanostructured materials and nanomaterials loaded with biocides, from 10 μg/L to 100 mg/L total weight, following standard protocols. The most eco-friendly and simultaneously efficient anti-fouling solution against the two photosynthetic species (nanoclays loaded with ZnPT) was then tested on mussels to assess its lethal efficacy (LC 50  = 123 μg/L) and compared with free biocide (LC 50  = 211 μg/L) and unloaded material (LC 50  > 1000 μg/L). A second exposure test with sub-lethal concentrations (lower than 100 μg/L), using mussels, was carried out to assess biochemical changes caused by the tested compounds. Oxidative stress, detoxification and neurotransmission markers were not responsive; however, different antioxidant patterns were found with free ZnPT and loaded nanoclay exposures. Thus, the immobilization of the biocide ZnPT into nanoclays proved to be a promising efficient and eco-friendly anti-fouling strategy.

  8. Integrated use of biomarkers and bioaccumulation data in Zebra mussel (Dreissena polymorpha) for site-specific quality assessment.

    Science.gov (United States)

    Binelli, A; Ricciardi, F; Riva, C; Provini, A

    2006-01-01

    One of the useful biological tools for environmental management is the measurement of biomarkers whose changes are related to the exposure to chemicals or environmental stress. Since these responses might vary with different contaminants or depending on the pollutant concentration reached in the organism, the support of bioaccumulation data is needed to prevent false conclusions. In this study, several persistent organic pollutants -- 23 polychlorinated biphenyl (PCB) congeners, 11 polycyclic aromatic hydrocarbons (PAHs), six dichlorodiphenyltricholroethane (DDT) relatives, hexachlorobenzene (HCB), chlorpyrifos and its oxidized metabolite -- and some herbicides (lindane and the isomers alpha, beta, delta; terbutilazine; alachlor; metolachlor) were measured in the soft tissues of the freshwater mollusc Zebra mussel (Dreissena polymorpha) from 25 sampling sites in the Italian portions of the sub-alpine great lakes along with the measure of ethoxyresorufin dealkylation (EROD) and acetylcholinesterase (AChE) activity. The linkage between bioaccumulation and biomarker data allowed us to create site-specific environmental quality indexes towards man-made chemicals. This classification highlighted three different degrees of xenobiotic contamination of the Italian sub-alpine great lakes: a high water quality in Lake Lugano with negligible pollutant levels and no effects on enzyme activities, an homogeneous poor quality for Lakes Garda, Iseo and Como, and the presence of some xenobiotic point-sources in Lake Maggiore, whose ecological status could be jeopardized, also due to the heavy DDT contamination revealed since 1996.

  9. Do invasive mussels restrict offshore phosphorus transport in Lake Huron?

    Science.gov (United States)

    Cha, Yoonkyung; Stow, Craig A; Nalepa, Thomas F; Reckhow, Kenneth H

    2011-09-01

    Dreissenid mussels were first documented in the Laurentian Great Lakes in the late 1980s. Zebra mussels (Dreissena polymorpha) spread quickly into shallow, hard-substrate areas; quagga mussels (Dreissena rostriformis bugensis) spread more slowly and are currently colonizing deep, offshore areas. These mussels occur at high densities, filter large water volumes while feeding on suspended materials, and deposit particulate waste on the lake bottom. This filtering activity has been hypothesized to sequester tributary phosphorus in nearshore regions reducing offshore primary productivity. We used a mass balance model to estimate the phosphorus sedimentation rate in Saginaw Bay, a shallow embayment of Lake Huron, before and after the mussel invasion. Our results indicate that the proportion of tributary phosphorus retained in Saginaw Bay increased from approximately 46-70% when dreissenids appeared, reducing phosphorus export to the main body of Lake Huron. The combined effects of increased phosphorus retention and decreased phosphorus loading have caused an approximate 60% decrease in phosphorus export from Saginaw Bay to Lake Huron. Our results support the hypothesis that the ongoing decline of preyfish and secondary producers including diporeia (Diporeia spp.) in Lake Huron is a bottom-up phenomenon associated with decreased phosphorus availability in the offshore to support primary production.

  10. One-year monitoring of core biomarker and digestive enzyme responses in transplanted zebra mussels (Dreissena polymorpha).

    Science.gov (United States)

    Palais, F; Dedourge-Geffard, O; Beaudon, A; Pain-Devin, S; Trapp, J; Geffard, O; Noury, P; Gourlay-Francé, C; Uher, E; Mouneyrac, C; Biagianti-Risbourg, S; Geffard, A

    2012-04-01

    A 12-month active biomonitoring study was performed in 2008-2009 on the Vesle river basin (Champagne-Ardenne, France) using the freshwater mussel Dreissena polymorpha as a sentinel species; allochthonous mussels originating from a reference site (Commercy) were exposed at four sites (Bouy, Sept-Saulx, Fismes, Ardre) within the Vesle river basin. Selected core biomarkers (acetylcholinesterase (AChE) activity, glutathione-S transferase (GST) activity, metallothionein concentration), along with digestive enzyme activities (amylase, endocellulase) and energy reserve concentrations (glycogen, lipids), were monitored throughout the study in exposed mussels. At the Fismes and Ardre sites (downstream basin), metallic and organic contamination levels were low but still high enough to elicit AChE and GST activity induction in exposed mussels (chemical stress); besides, chemical pollutants had no apparent deleterious effects on mussel condition. At the Bouy and Sept-Saulx sites (upstream basin), mussels obviously suffered from adverse food conditions which seriously impaired individual physiological state and survival (nutritional stress); food scarcity had however no apparent effects on core biomarker responses. Digestive enzyme activities responded to both chemical and nutritional stresses, the increase in energy outputs (general adaptation syndrome-downstream sites) or the decrease in energy inputs (food scarcity-upstream sites) leading to mid- or long-term induction of digestive carbohydrase activities in exposed mussels (energy optimizing strategy). Complex regulation patterns of these activities require nevertheless the use of a multi-marker approach to allow data interpretation. Besides, their sensitivity to natural confounding environmental factors remains to be precised.

  11. Pollutant monitoring in the Elbe river with the aid of the zebra mussel. A classification system - 1990-1997; Schadstoffueberwachung der Elbe mit der Dreikantmuschel. Ein Klassifizierungssystem - 1990-1997

    Energy Technology Data Exchange (ETDEWEB)

    Krieg, H.J. [Hydrobiologische Untersuchungen und Gutachten - HUuG, Tangstedt (Germany); Gaumert, T. [comps.] [Wasserguetestelle Elbe, Hamburg (Germany)

    1998-04-01

    The pollutant burden of the Elbe river can now be assessed more accurately with the aid of a new classification system based on pollutant accumulation in the soft tissue of the zebra mussel (Dreissena polymorpha), which provided the basis for a 7-stage pollution scale for individual substances. This closes a gap in pollution analysis of the Elbe river and makes statements on pollutant levels more efficient. [Deutsch] Die Schadstoffbelastung der Elbe kann mit Hilfe eines neuen und hier erstmalig vorgestellten Klassifizierungssystems besser als bisher bewertet werden. Die Auswertung angereicherter Schadstoffgehalte im Weichkoerper der in den Elbe-Messstationen gehaelterten Dreikantmuschel Dreissena polymorpha fuehrte zur Entwicklung einer siebenstufigen Belastungs-Skala fuer einzelne Substanzen. Mit diesem Verfahren kann somit ein offener Bereich bei der Bewertung der Schadstoffbelastung der Elbe geschlossen und die Gewaesserueberwachung mit einer hoeheren Aussagekraft betrieben werden. (orig.)

  12. PBDEs in freshwater mussels and fish from Flanders, Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Covaci, A.; Voorspoels, S.; Schepens, P. [Antwerp Univ. (Belgium). Toxicological Center; Bervoets, L.; Hoff, P.; Voets, J.; Campenhout, K. van; Blust, R. [Antwerp Univ. (Belgium). Dept. of Ecophysiology, Biochemistry and Toxicology

    2004-09-15

    Polybrominated diphenylethers (PBDEs), a class of brominated flame retardants (BFRs), are widely used in textiles, plastics, electronic equipment and other materials for more than 30 years. Due to their massive use, PBDEs have become ubiquitously present in aquatic organisms and it was recently evidenced that their levels seem to increase rapidly. Higher PBDE concentrations were found in biota from freshwater compared to similar marine species. This is probably due to a higher pollution load found near point pollution sources that are almost exclusively inland located. Zebra mussels (Dreissena polymorpha) fulfil the requirements of a good biomonitoring organism for freshwater ecosystems: they are easy to collect and to handle, are available in sufficient numbers, have a relative long lifespan, are sedentary and resistant to various types of pollution without suffering a too high mortality and have a high filtration rate which favours the bioaccumulation of organic contaminants. Fish species are another suitable tool for the biomonitoring of organic contaminants. The occurrence of PBDEs in fish species from Europe has already received some attention, but the amount of data is still limited. The aim of this study was to evaluate the occurence of PBDEs in zebra mussels and several representative freshwater fish species (eel, carp and gibel carp) at different sites in Flanders, Belgium. In parallel, other organohalogenated contaminants, such as polychlorinated biphenyls (PCBs), p,p'-DDE and hexachlorobenzene (HCB) were also measured and their relationship with PBDEs was investigated.

  13. Occurence of the Quagga Mussel Dreissena bugensis and the Zebra Mussel Dreissena polymorha in the Upper Mississippi River System

    Science.gov (United States)

    This manuscript reports on a range expansion of the invasive quagga mussel in the Great Rivers of the Upper Missippi River Basin. This research will be of interest to great river ecologists and to invasive species specialists.

  14. Towards a validation of a cellular biomarker suite in native and transplanted zebra mussels: A 2-year integrative field study of seasonal and pollution-induced variations

    Energy Technology Data Exchange (ETDEWEB)

    Guerlet, Edwige [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France); Ledy, Karine [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France); Meyer, Antoinette [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France); Giamberini, Laure [Laboratoire Ecotoxicite, Sante Environnementale, CNRS UMR 7146, Universite Paul Verlaine-Metz, Rue General Delestraint, F-57070 Metz (France)]. E-mail: giamb@univ-metz.fr

    2007-03-30

    Two of the questions raised in the validation process of biomarkers are their relevance in the identification and discrimination of environmental perturbations, and the influence of seasonal factors on these biological endpoints. Determining the advantages and restrictions associated with the use of native or transplanted animals and comparing their responses is also needed. To obtain this information, a 2-year integrative field study was conducted in the vicinity of a nuclear power plant in northeastern France. A station was located in the reservoir receiving the cooling waters of the plant, and two other sites were studied 2 km upstream and 5 km downstream from the reservoir's discharge in the Moselle river. Elevated temperatures, copper contamination and a 1.4-fold-concentration factor of dissolved salts affected water quality of the reservoir. Native and transplanted zebra mussels (Dreissena polymorpha) were collected monthly and their digestive glands were processed for histochemical determinations of the lysosomal and peroxisomal systems and of the lipofuscin and neutral lipid contents. The responses were quantified using automated image analysis and stereology. Apart from neutral lipid contents, there were no systematic seasonal patterns in mussel populations or from 1 year to another. Principal Component Analyses showed a general higher discrimination potential of biological responses in transplanted organisms compared to native ones. They also pointed out the relationships between the cellular and physiological markers and abiotic factors. The present multiple biomarker integrative approach in transplanted D. polymorpha brings promising elements in their validation process as relevant biomonitoring tools.

  15. Towards a validation of a cellular biomarker suite in native and transplanted zebra mussels: A 2-year integrative field study of seasonal and pollution-induced variations

    International Nuclear Information System (INIS)

    Guerlet, Edwige; Ledy, Karine; Meyer, Antoinette; Giamberini, Laure

    2007-01-01

    Two of the questions raised in the validation process of biomarkers are their relevance in the identification and discrimination of environmental perturbations, and the influence of seasonal factors on these biological endpoints. Determining the advantages and restrictions associated with the use of native or transplanted animals and comparing their responses is also needed. To obtain this information, a 2-year integrative field study was conducted in the vicinity of a nuclear power plant in northeastern France. A station was located in the reservoir receiving the cooling waters of the plant, and two other sites were studied 2 km upstream and 5 km downstream from the reservoir's discharge in the Moselle river. Elevated temperatures, copper contamination and a 1.4-fold-concentration factor of dissolved salts affected water quality of the reservoir. Native and transplanted zebra mussels (Dreissena polymorpha) were collected monthly and their digestive glands were processed for histochemical determinations of the lysosomal and peroxisomal systems and of the lipofuscin and neutral lipid contents. The responses were quantified using automated image analysis and stereology. Apart from neutral lipid contents, there were no systematic seasonal patterns in mussel populations or from 1 year to another. Principal Component Analyses showed a general higher discrimination potential of biological responses in transplanted organisms compared to native ones. They also pointed out the relationships between the cellular and physiological markers and abiotic factors. The present multiple biomarker integrative approach in transplanted D. polymorpha brings promising elements in their validation process as relevant biomonitoring tools

  16. Changes in the dreissenid community in the lower Great Lakes with emphasis on southern Lake Ontario

    Science.gov (United States)

    Mills, Edward L.; Chrisman, Jana R.; Baldwin, Brad; Owens, Randall W.; O'Gorman, Robert; Howell, Todd; Roseman, Edward F.; Raths, Melinda K.

    1999-01-01

    A field study was conducted in the lower Great Lakes to assess changes in spatial distribution and population structure of dreissenid mussel populations. More specifically, the westward range expansion of quagga mussel into western Lake Erie and toward Lake Huron was investigated and the shell size, density, and biomass of zebra and quagga mussel with depth in southern Lake Ontario in 1992 and 1995 were compared. In Lake Erie, quagga mussel dominated the dreissenid community in the eastern basin and zebra mussel dominated in the western basin. In southern Lake Ontario, an east to west gradient was observed with the quagga mussel dominant at western sites and zebra mussel dominant at eastern locations. Mean shell size of quagga mussel was generally larger than that of zebra mussel except in western Lake Erie and one site in eastern Lake Erie. Although mean shell size and our index of numbers and biomass of both dreissenid species increased sharply in southern Lake Ontario between 1992 and 1995, the increase in density and biomass was much greater for quagga mussels over the 3-year period. In 1995, zebra mussels were most abundant at 15 to 25 m whereas the highest numbers and biomass of quagga mussel were at 35 to 45 m. The quagga mussel is now the most abundant dreissenid in areas of southern Lake Ontario where the zebra mussel was once the most abundant dreissenid; this trend parallels that observed for dreissenid populations in the Dneiper River basin in the Ukraine.

  17. Uptake and elimination of [9-14C]phenanthrene in the turkey wing mussel (Arca zebra)

    International Nuclear Information System (INIS)

    Solbakken, J.E.; Knap, A.H.; Searle, C.E.; Palmork, K.H.

    1983-01-01

    Turkey wing mussels of both sexes were collected from Harrington Sound, Bermuda and dosed after a week-long acclimation period with [9- 14 C]phenanthrene (714 MBq/mmol). They were transferred into 8 liters of seawater containing 8 μg of labelled phenanthrene. Results show that the accumulation of labelled phenanthrene in the turkey wing mussel was very low compared to that found in other species. In the hepatopancreas, the uptake of phenanthrene based on the water concentration was only 4% of the corresponding value found in the calico clam (Macrocallista maculata) inhabiting the same area. In comparison, the uptake of phenanthrene in a temperate mollusc such as the horse mussel (Modiola modiolus) was also considerably higher than in the turkey wing (approx. 4 times). It therefore seems likely that these are due to species variations rather than environmental variations between subtropical and temperate areas

  18. Zebra Stripes through the Eyes of Their Predators, Zebras, and Humans.

    Directory of Open Access Journals (Sweden)

    Amanda D Melin

    Full Text Available The century-old idea that stripes make zebras cryptic to large carnivores has never been examined systematically. We evaluated this hypothesis by passing digital images of zebras through species-specific spatial and colour filters to simulate their appearance for the visual systems of zebras' primary predators and zebras themselves. We also measured stripe widths and luminance contrast to estimate the maximum distances from which lions, spotted hyaenas, and zebras can resolve stripes. We found that beyond ca. 50 m (daylight and 30 m (twilight zebra stripes are difficult for the estimated visual systems of large carnivores to resolve, but not humans. On moonless nights, stripes are difficult for all species to resolve beyond ca. 9 m. In open treeless habitats where zebras spend most time, zebras are as clearly identified by the lion visual system as are similar-sized ungulates, suggesting that stripes cannot confer crypsis by disrupting the zebra's outline. Stripes confer a minor advantage over solid pelage in masking body shape in woodlands, but the effect is stronger for humans than for predators. Zebras appear to be less able than humans to resolve stripes although they are better than their chief predators. In conclusion, compared to the uniform pelage of other sympatric herbivores it appears highly unlikely that stripes are a form of anti-predator camouflage.

  19. Grazing rate of zebra mussel in a shallow eutrophicated bay of the Baltic Sea.

    Science.gov (United States)

    Oganjan, Katarina; Lauringson, Velda

    2014-12-01

    Benthic suspension feeding is an important process in coastal ecosystems. Among all the World's oceans, coastal ecosystems are the most modified by human impact and changing at accelerating pace. It is complicated to understand, how various environmental factors affect feeding rates of suspension feeders in their natural habitats. Thus, shapes of such relationships are poorly described for several intersections of environmental gradients. In this study, relationships between grazing rates of an invasive bivalve Dreissena polymorpha and ambient environmental factors were investigated in a turbid eutrophic bay of the central Baltic Sea using a novel modelling method of Boosted Regression Trees (BRT), a statistical tool able to handle non-normal distributions, complex relationships, and interactive effects. Feeding rates of mussels were derived from field populations by measuring the content of algal pigments in specimens collected from their natural habitat. The content of pigments was converted to feeding rate separately each time using field experiments measuring simultaneously the content of pigments and biodeposition of mussels. The results suggest that feeding rates of D. polymorpha are related to several environmental factors which gradients outreach the optimal range for the local mussel population. All the observed effects were non-linear with complex shapes. Variability along the resource gradient was the most important predictor of mussel feeding, followed by salinity and disturbance caused by wind. The most important interaction occurred between disturbance and resource gradient, while feeding function showed more plasticity along the latter. Mapping of environmental tipping points with the aid of machine learning methods may enable to concentrate the most relevant information about ecological functions worldwide. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Pathogens and diseases of freshwater mussels in the United States: Studies on bacterial transmission and depuration

    Science.gov (United States)

    Starliper, Clifford E.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

    2011-01-01

    Unionid mussels are recognized as important contributors to healthy aquatic ecosystems, as well as bioindicators of environmental perturbations. Because they are sedentary, filter feeding animals and require hosts (i.e., fishes) to transform embryonic glochidia, mussels are susceptible to direct adverse environmental parameters, and indirect parameters that restrict the timely presence of the host(s). Their numbers have declined in recent decades to a point that this fauna is regarded as one of the most imperiled in North America. The most significant threat to populations of native unionids in recent years has been the introduction and spread of zebra mussels Dreissena polymorpha. Many federal and state agencies, and private interests are now engaged in mussel conservation efforts, including collecting selected imperiled species from impacted rivers and lakes and propagating them at refuges for future population augmentations. One essential consideration with mussel propagation and their intensive culture at refugia is the prevention of pathogen introductions and control of diseases. Currently, there are few reports of etiological agents causing diseases among freshwater mussels; however, because of increased observations of mussel die-offs in conjunction with transfers of live animals between natural waters and refugia, disease problems can be anticipated to emerge. This review summarizes research to develop bacterial isolation techniques, study pathogen transmission between fish and mussels, identify causes of seasonal mussel die-offs, and develop non-destructive methods for pathogen detection. These efforts were done to develop disease preventative techniques for use by resource managers to avoid potential large-scale disease problems in restoration and population augmentation efforts among imperiled populations.

  1. New method for control of biological fouling in pipelines based on elevated partial pressures of carbon dioxide or combustion exhaust gases.

    Energy Technology Data Exchange (ETDEWEB)

    B.J. Watten; R.E. Sears; R.F. Bumgardner [U.S. Geological Survey - Leetown Science Center, Kearneysville, WV (United States)

    2005-07-01

    Zebra mussels (Dreissena polymorpha) and Asian clams (Corbicula fluminea) are major macro fouling species of water conduits used in industrial and power station raw water/condensor systems. Control typically involves manual scraping and use of thermal treatment, deoxygenation or biocides. The costs of control and system damage resulting from fouling in the United States alone have been estimated at $1 billion/year. There is a pressing need for new economical and safe control strategies. Aquatic species in general are intolerant to increases in PCO{sub 2} given its effect on water, blood and hemolymph pH. These species are also sensitive to increases in elevated total dissolved gas pressure. The gas bubble disease that develops following exposure can, as with CO{sub 2} exposure, lead to mortality. We are exploiting this sensitivity by developing a control method based on manipulation of PCO{sub 2} or power plant exhaust gas (CO{sub 2}, 14%; SO{sub 2}, 0.3%), i.e., the supersaturation of hemolymph and tissues with gas followed by an induced (short term) pressure release designed to induce formation of gas emboli. SO{sub 2} present in stack gas acts with CO{sub 2} to reduce water and hemolymph pH so as to reduce required exposure periods. System effluents are degassed, CO{sub 2} recovered and pH adjusted if needed with alkaline reagents. Test results indicate the new process is effective at controlling C. fluminea as well as other target species, including crustaceans and fish. Required exposure periods (LT50) are short and decrease with increasing gas supersaturation levels. Gas recovery and reuse methods developed have reduced gas requirements by 85% making the method attractive economically and environmentally. 40 refs., 8 figs., 1 tab.

  2. Cationic surfactants for control of fresh- and saltwater mollusks in nuclear cooling systems

    International Nuclear Information System (INIS)

    Post, R.M.; Mallen, E.; Lehmann, F.

    1991-01-01

    One result of the release of the US Nuclear Regulatory Commission's Generic Letter 89-13, Service Water Problems Affecting Safety-Related Equipment, was the heightened awareness of the nuclear industry to the problems of macrofouling in heat exchange systems. The principal mollusk species that contribute to freshwater macrofouling problems are Asiatic Clam (southern United States) and Zebra Mussel (Great Lakes). The predominant saltwater fouling mollusks are the Blue Mussel (Pacific, northern Atlantic), Ribbed Mussel (southern Atlantic, Gulf Coast), and American Oyster (Atlantic, Gulf Coast). The nuclear community's awareness of macrofouling problems and the ineffectiveness of intermittent chlorination programs have led to the development of several chemical control technologies for eliminating macrofouling organism infestation. One technology that has proven effective for the control of macrofouling organisms is the periodic addition of a combination of two cationic charged surfactants, specifically, alkyldimethylbenzylammonium chloride (QUAT) and dodecyl guanidine hydrochloride (DGH). Experience with the cationic surfactants at several nuclear power plants is reported

  3. Development of kit for detection of the larvae of fouling organisms flowing in the power station's water intake conduits

    International Nuclear Information System (INIS)

    Yanagawa, T.

    2009-01-01

    Massive settlement of the mussel Mytilus galloprovincialis and the barnacle Megabalanus rosa often causes serious problems in coastal industries: electric power stations, fisheries, marine services. This paper describes development of rapid and sensitive methods for on-site monitoring the larval settlement of the fouling species to make efficient the antifouling systems. (author)

  4. Susceptibility of quagga mussels (Dreissena rostriformis bugensis) to hot-water sprays as a means of watercraft decontamination.

    Science.gov (United States)

    Comeau, Sean; Rainville, Scott; Baldwin, Wen; Austin, Emily; Gerstenberger, Shawn; Cross, Chad; Wong, Wai Hing

    2011-03-01

    The recent spread of dreissenid mussels to various bodies of water in the western US has sparked interest by many state and federal agencies to develop protocols to stop further expansion. Quagga mussels (Dreissena rostriformis bugensis) are of particular importance as they are currently the most widespread dreissenid species in the region. This project examined the susceptibility of quagga mussels to hot-water sprays at different temperatures and durations of spray contact at Lake Mead (Nevada-Arizona, USA). Emersed adult quagga mussels were exposed to hot-water sprays at 20, 40, 50, 54, 60, 70, and 80°C for 1, 2, 5, 10, 20, 40, 80, and 160 s. Sprays at ≥60°C for 5 s were shown to be 100% lethal. Sprays of 54°C for 10 s, 50°C for 20 s, and 40°C for 40 s also resulted in 100% mortality. A spray temperature of 60°C for 5 s is recommended for mitigating fouling by quagga mussels.

  5. Genetic diversity of piroplasms in plains zebra (Equus quagga burchellii) and Cape mountain zebra (Equus zebra zebra) in South Africa.

    Science.gov (United States)

    Bhoora, Raksha; Buss, Peter; Guthrie, Alan J; Penzhorn, Barend L; Collins, Nicola E

    2010-11-24

    Seventy EDTA blood samples collected from plains zebra (Equus quagga burchellii) and Cape mountain zebra (Equus zebra zebra) were screened for the presence of piroplasm parasite DNA using quantitative T. equi-specific and B. caballi-specific TaqMan real-time PCR (qPCR) tests. T. equi parasite DNA was detected in 60 samples, 19 of which were also positive for B. caballi. Approximately 1480bp of the piroplasm 18S rRNA gene was amplified and sequenced from 17 samples, while the V4 hypervariable region of the 18S rRNA gene was amplified, cloned and sequenced from 31 samples. BLASTN analysis revealed that all of the sequences obtained were most similar to T. equi genotypes and not B. caballi genotypes. Although Babesia parasites were present in some of these samples, as indicated by qPCR, the parasitaemia may have been too low to allow detection by cloning of PCR products from a mixed infection. Sequence analyses of both the full-length and the V4 hypervariable region of the T. equi 18S rRNA gene revealed the existence of 13 new T. equi sequences from zebra, confirming the existence of sequence heterogeneity in the rRNA genes of the parasites that cause equine piroplasmosis, and further suggesting that there may be additional, as yet unidentified, T. equi and B. caballi 18S rRNA sequences present in the horse and zebra populations in South Africa. The occurrence of previously unrecognized sequence variation could pose a potential problem in the implementation of diagnostic tests targeting the 18S rRNA gene. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Genotoxicity and activation of cellular defenses in transplanted zebra mussels Dreissena polymorpha along the Seine river.

    Science.gov (United States)

    Châtel, Amélie; Faucet-Marquis, Virginie; Gourlay-Francé, Catherine; Pfohl-Leszkowicz, Annie; Vincent-Hubert, Françoise

    2015-04-01

    The aim of the present study was to confirm the relevance of studying DNA adduct formation in a field study. In that context, freshwater mussels Dreissena polymorpha, collected in a reference station, were transplanted in different sites with a pollution gradient. After one and two months, mussels were collected and DNA adduct formation was analyzed using the (32)P post labelling technique on both gills and digestive glands. In addition, the expression of genes involved in the detoxification system (catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), HSP70, aryl hydrocarbon receptor (AHR), P glycoprotein (PgP), metallothionein (MT)) was assessed by RT-PCR. DNA adducts were observed at amount comparable to data from literature. Increase of DNA adducts after two months of transplantation could be correlated with strong modulation of gene expression implicated in detoxification processes. Indeed, PgP and HSP70 gene expressions were similarly induced in gills and digestive glands while SOD and CAT expressions were down regulated in both tissues. AHR, GST and MT genes were differently regulated depending upon the tissue studied and the level of contamination in the different sites. We demonstrated that mussels transplanted in the different stations with pollution gradient were able to biotransform PAHs, assessed by DNA adduct formation and the high decrease of detoxification genes. Specific DNA adducts pattern obtained after one and two month mussel transplantations demonstrated the relevance of DNA adduct as biomarker of environmental pollution. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Invasive species research to meet the needs of resource management and planning.

    Science.gov (United States)

    Papeş, M; Sällström, M; Asplund, T R; Vander Zanden, M J

    2011-10-01

    As zebra mussels (Dreissena polymorpha) continue to spread among inland lakes of the United States and Canada, there is growing interest from professionals, citizens, and other stakeholders to know which lakes are likely to be colonized by zebra mussels. Thus, we developed a classification of lake suitability for zebra mussels on the basis of measured or estimated concentrations of dissolved calcium in lake water and applied the classification to >11,500 lakes in Wisconsin and the Upper Peninsula of Michigan. The majority of lakes (58%) were classified as unsuitable (zebra mussels, 27% were identified as suitable (≥21 mg/L Ca), and 15% were classified as borderline suitable (≥10 and zebra mussel records for which data on dissolved calcium were available, our method classified 74 as suitable and 3 as borderline suitable. To communicate this lake-specific suitability information and to help prioritize regional efforts to monitor and prevent the expansion of zebra mussels and other invasive species, we developed a web-based interface (available from http://www.aissmartprevention.wisc.edu/). Although we are still uncertain of how access to suitability information ultimately affects decision making, we believe this is a useful case study of building communication channels among researchers, practitioners, and the public. ©2011 Society for Conservation Biology.

  8. Procedures for conducting underwater searches for invasive mussels (Dreissena sp.)

    Science.gov (United States)

    Adams, Noah

    2010-01-01

    Zebra mussels (Dreissena polymorpha) were first detected in the Great Lakes in 1988. They were likely transported as larvae or young adults inside the ballast tanks of large ocean-going ships originating from Europe. Since their introduction, they have spread throughout the Eastern, Midwestern, and Southern United States. In 2007, Quagga mussels (Dreissena rostriformis bugensis) were found in the Western United States in Lake Mead, Nevada; part of the Lower Colorado River Basin. State and Federal managers are concerned that the mussels (hereafter referred to as dreissenid mussels or mussels) will continue to spread to the Columbia River Basin and have a major impact on the region?s ecosystem, water delivery infrastructure, hydroelectric projects, and the economy. The transport and use of recreational watercraft throughout the Western United States could easily result in spreading mussels to the Columbia River Basin. The number of recreational watercraft using Lake Mead can range from 350 to 3,500 a day (Bryan Moore, National Park Service, oral commun., June 21, 2008). Because recreational watercrafts are readily moved around and mussels may survive for a period of time when they are out of the water, there is a high potential to spread mussels from Lake Mead to other waterways in the Western United States. Efforts are being made to prevent the spread of mussels; however, there is great concern that these efforts will not be 100 percent successful. When prevention efforts fail, early detection of mussels may provide an opportunity to implement rapid response management actions to minimize the impact. Control and eradication efforts are more likely to be successful if they are implemented when the density of mussels is low and the area of infestation is small. Once the population grows and becomes established, the mussels are extremely difficult, if not impossible, to control. Although chemicals may be used to kill the mussels, the chemicals that are currently

  9. Toxicity of potassium chloride to veliger and byssal stage dreissenid mussels related to water quality

    Science.gov (United States)

    Moffitt, Christine M.; Stockton-Fiti, Kelly A.; Claudi, Renata

    2016-01-01

    Natural resource managers are seeking appropriate chemical eradication and control protocols for infestations of zebra mussels, Dreissena polymorpha (Pallas, 1769), and quagga mussels. D. rostiformis bugensis (Andrusov, 1897) that have limited effect on non-target species. Applications of low concentrations of potassium salt (as potash) have shown promise for use where the infestation and treatment can be contained or isolated. To further our understanding of such applications and obtain data that could support a pesticide registration, we conducted studies of the acute and chronic toxicity of potassium chloride to dreissenid mussels in four different water sources from infested and non-infested locations (ground water from northern Idaho, surface water from the Snake River, Idaho, USA, surface water from Lake Ontario, Ontario, Canada, and surface water from the Colorado River, Arizona, USA). We found short term exposure of veligers (29 d) at concentrations of 100 and 200 mg/L KCl. Rapid mortality occurred within 10 d of exposure to concentrations of 200 mg/L KCl, regardless of water source. Kaplan-Meier estimates of mean survival of byssal mussels in 100 mg/L KCl prepared in surface water from Idaho and Lake Ontario were 4.9 or 6.9 d, respectively; however, mean survival of mussels tested in the Colorado River water was > 23 d. The sodium content of the Colorado River water was nearly three times that measured in waters from the other locations, and we hypothesized sodium concentrations may affect mussel survival. To test our hypothesis, we supplemented Snake River and Lake Ontario water with NaCl to equivalent conductivity as the Colorado River, and found mussel survival increased to levels observed in tests of veliger and byssal mussels in Colorado River water. We recommend KCl disinfection and eradication protocols must be developed to carefully consider the water quality characteristics of treatment locations.

  10. Chaetogaster limnaei (annelida: oligochaeta) as a parasite of the zebra mussel Dreissena polymorpha, and the quagga mussel Dreissena bugensis (mollusca: bivalvia).

    Science.gov (United States)

    Conn, D B; Ricciardi, A; Babapulle, M N; Klein, K A; Rosen, D A

    1996-01-01

    Dreissenid mussels, Dreissena polymorpha and D. bugensis, were found to be infected by the naidid oligochaete Chaetogaster limnaei at four sites in the St. Lawrence River. This is the first report of this species infecting dreissenids anywhere in the world. Most worms inhabited the mantle cavity, where they caused erosion of the mantle and gill epithelia as determined by histopathological examination. Others penetrated various tissues; one had invaded the ovary and was feeding on oocytes and ovarian tissues. Of 606 mussels examined, 166 (27.4%) harbored at least 1 C. limnaei. The prevalence varied between 1% and 80%, depending on the collection site and date. The worms were slightly but significantly more prevalent in D. bugensis than in D. polymorpha. The intensity ranged from 1 to 18 worms per infected host. Variations in prevalence and intensity were not related to the size or sex of the host, but the data did suggest some seasonality.

  11. Shell Biofilm Nitrification and Gut Denitrification Contribute to Emission of Nitrous Oxide by the Invasive Freshwater Mussel Dreissena polymorpha (Zebra Mussel)

    Science.gov (United States)

    Svenningsen, Nanna B.; Heisterkamp, Ines M.; Sigby-Clausen, Maria; Larsen, Lone H.; Nielsen, Lars Peter; Stief, Peter

    2012-01-01

    Nitrification in shell biofilms and denitrification in the gut of the animal accounted for N2O emission by Dreissena polymorpha (Bivalvia), as shown by gas chromatography and gene expression analysis. The mussel's ammonium excretion was sufficient to sustain N2O production and thus potentially uncouples invertebrate N2O production from environmental N concentrations. PMID:22492461

  12. New non-stick expoxy-silicone water-based coatings part 1: Physical and surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Garti, N. [Hebrew Univ. of Jerusalem (Israel); Smith, J. [Decora Manufacturing, Fort Edward, NY (United States)

    1995-06-01

    In search for tomorrow`s technology for water-based coating, Decora Manufacturing and The Hebrew University of Jerusalem, have initiated an intensive research program for designing, developing and manufacturing new coatings based on cross-linked, room temperature-cured silicone-expoxy resins. The new water-borne coatings have most exciting characteristics such as: non-stick properties, effective release, high lubricity, corrosion protection and abrasion resistance. The coatings are environmentally-friendly and easy to use. These coatings are ideal for marine, agricultural, industrial and maintenance applications. This paper brings quantitative measurements related to the dispersion technology (particle size, stability, shelf-life), to the non-stick properties (deicing, low surface energy, easy-release and non-stick), lubricity, adhesion to substrates, viscosity, dynamic and static friction coefficients and environmental impact (low VOC, non-toxicity, low-leaching). The coating was tested in various industrial coating systems and was found to exhibit excellent non-stick and release properties. Special attention was given to Zebra Mussels, Quagga Mussels and other bacterial and algeal bioforms. The coating proved to be efficient as foul-release coating with very low biofouling adhesion. The low adhesion applied to many other substances in which foul-release means easy-clean and low-wear.

  13. Electrocardiography of Grevy's zebras (Equus grevyi).

    Science.gov (United States)

    Myers, Debbie A; Citino, Scott; Mitchell, Mark A

    2008-09-01

    Electrocardiograms (ECGs) are a good baseline test for assessing cardiac rhythm. ECGs have not been reported in any zebra species and in very few Perissodactyla species. Standard limb, six-lead ECGs were recorded in 23 anesthetized Grevy's zebras (Equus grevyi). Heart rate, RR interval, P-wave duration, RR maximum/minimum, PR interval, QRS duration, QT interval, ST segment deviation, P-wave amplitude, QRS amplitude, and T-wave amplitude were measured and calculated from lead II ECGs from these Grevy's zebras. Several variables were tested, including gender, age (0-24, 24-48, 48-180, and >180 mo), weight (350 kg), pregnancy status, and anesthetic differences (standard dose or supplemented dose), to see if they affected ECG values in these animals. There were no significant differences in any of the ECG parameters between genders. RR and QT intervals were longer in older zebras; heart rates were faster in younger zebras. The RR and PR intervals, as well as the QRS duration, were greater in heavier zebras; heart rates were faster in lighter zebras. The RR interval was significantly longer in pregnant zebras. There were no significant differences in any of the ECG parameters for zebras anesthetized with a standardized dose of the drug combination etorphine-detomidine-acepromazine compared to those receiving additional supplements of these drugs and/or ketamine. All other parameters were not significantly different among groups, except where noted previously. The results of this research indicate that differences in ECG parameters in zebras may occur between animals of different ages, weights, and pregnancy status and that these factors should be considered when interpreting the respective ECGs of these zebras.

  14. Monitoring biofouling communities could reduce impacts to mussel aquaculture by allowing synchronisation of husbandry techniques with peaks in settlement.

    Science.gov (United States)

    Sievers, Michael; Dempster, Tim; Fitridge, Isla; Keough, Michael J

    2014-02-01

    Fouling organisms in bivalve aquaculture cause significant economic losses for the industry. Managing biofouling is typically reactive, and involves time- and labour-intensive removal techniques. Mussel spat settlement and biofouling were documented over 20 months at three mussel farms within Port Phillip Bay (PPB), Australia to determine if knowledge of settlement patterns could assist farmers in avoiding biofouling. Mussel spat settlement was largely confined to a 2-month period at one farm. Of the problematic foulers, Ectopleura crocea settlement varied in space and time at all three farms, whilst Ciona intestinalis and Pomatoceros taeniata were present predominantly at one farm and exhibited more distinct settlement periods. Within PPB, complete avoidance of biofouling is impossible. However, diligent monitoring may help farmers avoid peaks in detrimental biofouling species and allow them to implement removal strategies such as manual cleaning, and postpone grading and re-socking practices, until after these peaks.

  15. Temporal and basin-specific population trends of quagga mussels on soft sediment of a multi-basin reservoir

    Science.gov (United States)

    Caldwell, Timothy J; Rosen, Michael R.; Chandra, Sudeep; Acharya, Kumud; Caires, Andrea M; Davis, Clinton J.; Thaw, Melissa; Webster, Daniel M.

    2015-01-01

    Invasive quagga (Dreissena bugnesis) and zebra (Dreissena ploymorpha) mussels have rapidly spread throughout North America. Understanding the relationships between environmental variables and quagga mussels during the early stages of invasion will help management strategies and allow researchers to predict patterns of future invasions. Quagga mussels were detected in Lake Mead, NV/AZ in 2007, we monitored early invasion dynamics in 3 basins (Boulder Basin, Las Vegas Bay, Overton Arm) bi-annually from 2008-2011. Mean quagga density increased over time during the first year of monitoring and stabilized for the subsequent two years at the whole-lake scale (8 to 132 individuals·m-2, geometric mean), in Boulder Basin (73 to 875 individuals·m-2), and in Overton Arm(2 to 126 individuals·m-2). In Las Vegas Bay, quagga mussel density was low (9 to 44 individuals·m-2), which was correlated with high sediment metal concentrations and warmer (> 30°C) water temperatures associated with that basin. Carbon content in the sediment increased with depth in Lake Mead and during some sampling periods quagga density was also positively correlated with depth, but more research is required to determine the significance of this interaction. Laboratory growth experiments suggested that food quantity may limit quagga growth in Boulder Basin, indicating an opportunity for population expansion in this basin if primary productivity were to increase, but was not the case in Overton Arm. Overall quagga mussel density in Lake Mead is highly variable and patchy, suggesting that temperature, sediment size, and sediment metal concentrations, and sediment carbon content all contribute to mussel distribution patterns. Quagga mussel density in the soft sediment of Lake Mead expanded during initial colonization, and began to stabilize approximately 3 years after the initial invasion.

  16. Cardiac evaluation of anesthetized Grevy's zebras (Equus grevyi).

    Science.gov (United States)

    Adin, Darcy B; Maisenbacher, Herbert W; Ojeda, Nyurka; Fiorello, Christine V; Estrada, Amara H; Prosek, Robert; Citino, Scott B

    2007-02-01

    To determine ECG and echocardiographic measurements in healthy anesthetized Grevy's zebras (Equus grevyi). 20 healthy zebras. Auscultation, base-apex ECG, and echocardiography were performed on anesthetized zebras. Low-grade systolic murmurs were detected in the left basilar region in 4 of 20 zebras. Evaluation of ECGs from 19 zebras revealed sinus rhythm with a predominantly negative QRS complex and a mean +/- SD heart rate of 67 +/- 10 beats/min. Echocardiograms of sufficient image quality were obtained for 16 zebras. Interventricular septal thickness in diastole, left ventricular chamber in diastole and systole, left atrial diameter, and left ventricular mass were significantly and moderately correlated with estimated body weight (r values ranged from 0.650 to 0.884). Detectable swirling of blood in the right and sometimes the left ventricles was detected in 9 of 16 zebras, whereas physiologic regurgitation of blood was detected for the aortic valve in 3 zebras, pulmonary valve in 2 zebras, mitral valve in 2 zebras, and tricuspid valve in 1 zebra. Results of this study provide reference information for use in the cardiac evaluation of anesthetized Grevy's zebras.

  17. Population genetic diversity and hybrid detection in captive zebras.

    Science.gov (United States)

    Ito, Hideyuki; Langenhorst, Tanya; Ogden, Rob; Inoue-Murayama, Miho

    2015-08-21

    Zebras are members of the horse family. There are three species of zebras: the plains zebra Equus quagga, the Grevy's zebra E. grevyi and the mountain zebra E. zebra. The Grevy's zebra and the mountain zebra are endangered, and hybridization between the Grevy's zebra and the plains zebra has been documented, leading to a requirement for conservation genetic management within and between the species. We characterized 28 microsatellite markers in Grevy's zebra and assessed cross-amplification in plains zebra and two of its subspecies, as well as mountain zebra. A range of standard indices were employed to examine population genetic diversity and hybrid populations between Grevy's and plains zebra were simulated to investigate subspecies and hybrid detection. Microsatellite marker polymorphism was conserved across species with sufficient variation to enable individual identification in all populations. Comparative diversity estimates indicated greater genetic variation in plains zebra and its subspecies than Grevy's zebra, despite potential ascertainment bias. Species and subspecies differentiation were clearly demonstrated and F1 and F2 hybrids were correctly identified. These findings provide insights into captive population genetic diversity in zebras and support the use of these markers for identifying hybrids, including the known hybrid issue in the endangered Grevy's zebra.

  18. Evaluation of the natural product antifoulant, zosteric acid, for preventing the attachment of quagga mussels--a preliminary study.

    Science.gov (United States)

    Ram, Jeffrey L; Purohit, Sonal; Newby, Bi-Min Zhang; Cutright, Teresa J

    2012-01-01

    The effectiveness of zosteric acid, a natural antifoulant from the marine seagrass Zostera marina, in preventing the attachment of quagga mussels, a biofouling bivalve, was investigated. Animals were exposed to water containing zosteric acid ranging from 0 to 1000 ppm, and their attachment to the container glass walls was tracked with time. 500 ppm zosteric acid was not effective at detaching animals that had already attached, but was able to prevent the attachment of most unattached animals for two days. The anti-fouling effect increased with higher concentration. Low concentrations (250 ppm and below) were not effective at preventing attachment; however, 1000 ppm zosteric acid prevented attachment of mussels for the first three days of zosteric acid exposure, and only 20% of the mussels were attached by day 4. In contrast, animals in control (no zosteric acid) solutions began to attach within one day. In conclusion, zosteric acid is an effective natural product deterrent of attachment of a biofouling bivalve.

  19. Comparison of bioaccumulation and biomarker responses in Dreissena polymorpha and D. bugensis after exposure to resuspended sediments.

    Science.gov (United States)

    Schäfer, S; Hamer, B; Treursić, B; Möhlenkamp, C; Spira, D; Korlević, M; Reifferscheid, G; Claus, E

    2012-05-01

    The zebra mussel Dreissena polymorpha is widely used as sentinel organism for the assessment of environmental contamination in freshwater environments. However, in the River Rhine (Germany), the D. polymorpha population is declining, whereas the closely related quagga mussel D. bugensis is found in high numbers at some sites. In the present laboratory study, D. polymorpha and D. bugensis were exposed to resuspended native sediments for ≤2 weeks. Wet sediments (quagga mussel can be used as alternative test organism for the zebra mussel.

  20. Distribution and ecology of Dreissena polymorpha (pallas) and Dreissena bugensis (andrusov) in the upper Volga basin

    Science.gov (United States)

    Shcherbina, G. Kh; Buckler, D.R.

    2006-01-01

    This paper presents data on contemporary distribution patterns of two species of Dreissenidae, the zebra mussel (Dreissena polymorpha) and the Quagga mussel (Dreissena bugensis), and their role in ecosystem processes in the Ivan'kovo, Uglich, Rybinsk, and Gorky Reservoirs of the Upper Volga River basin. The role of zebra mussel was also studied in experimental mesocosms of 15 m3. Maximum abundance and species diversity of macroinvertebrates, especially of leeches, polychaetes, crustaceans, and heterotopic insects, were attained in the portions of reservoirs where Dreissenidae were present and in experimental mesocosms where zebra mussel biomass was the highest. In the mesocosm studies, the presence of zebra mussel druses (colonies) provided shelter for macroinvertebrates, reducing their vulnerability to predation by perch (Perca fluviatills) larvae and yearlings, thereby increasing macroinvertebrate species diversity. It was shown that in addition to its role in aquatic biocenosis (ecological community) formation and water purification, Dreissenidae are important food objects for benthophagous fishes, especially roach (Rutilus rutilus). Examination of intestines of benthophagous fishes showed that the length of Dreissenidae ranged from 5 to 20 mm in roach; from 4 to 14 mm in silver bream (Blicca bjoerkna), and from 2 to 10 mm in bream (Abramis brama). The largest mussels consumed were Quagga mussels up to 30 mm, noted in the predatory cyprinid, ide (Leuciscus idus). Copyright ?? 2006 by ASTM International.

  1. Extirpation of freshwater mussels (Bivalvia: Unionidae) following the invasion of dreissenid mussels in an interconnecting river of the Laurentian Great Lakes

    Science.gov (United States)

    Schloesser, Don W.; Metcalfe-Smith, Janice L.; Kovalak, William P.; Longton, Gary D.; Smithee, Rick D.

    2006-01-01

    Previous (1992-1994) surveys for native freshwater mussels (Unionidae) along main channels of the Detroit River showed that unionids had been extirpated from all but four sites in the upper reaches of the river due to impacts of dreissenid mussels (Dreissena polymorpha and D. bugensis). These four sites were surveyed again in 1998 using the same sampling method (timed-random searches) to determine if they may serve as ''refugia'' where unionids and dreissenids co-exist. Two additional sites were sampled using additional methods (excavated-quadrat and line-transect searches) for comparison with unpublished data collected in 1987 and 1990. A total of four individuals of four species (Actinonaias ligamentina, Cyclonaias tuberculata, Lasmigona complanata and Pleurobema sintoxia) were found by timed-random searches at four sites in 1998 compared to 720 individuals of 24 species in 1992 and 39 individuals of 13 species in 1994. Excavated-quadrat and line-transect searches at the two additional sites yielded only one live specimen of Ptychobranchus fasciolaris compared to 288 individuals of 18 species in 1987 and 1990. Results of this study suggest that remaining densities of unionids in channels of the Detroit River are too low to support viable reproducing populations of any species. Therefore, we conclude that unionids have been extirpated from main channels of the Detroit River due to dreissenid infestation. As the Detroit River was one of the first water bodies in North America to be invaded by dreissenids, it is likely that unionids will also be extirpated from many other rivers and lakes across eastern North America over the next few decades. Resource agencies should be encouraged to implement active management programs to protect remaining unionid populations from zebra mussels.

  2. Comparison of lipid peroxidation and catalase response in invasive dreissenid mussels exposed to single and multiple stressors.

    Science.gov (United States)

    Nowicki, Carly J; Kashian, Donna R

    2018-02-14

    Dreissenid mussels Dreissena bugensis (quagga mussel) and Dreissena polymorpha (zebra mussel) are prolific invasive species to the freshwaters of the United States and Western Europe. In the Great Lakes, D. polymorpha has initially dominated the system since its invasion in the mid-1980s; however, recently D. bugensis has displaced D. polymorpha as the dominant species. Dreissena bugensis has several competitive advantages over D. polymorpha, including greater tolerances to deeper and colder waters and lower respiration rates. Nevertheless, physiological differences between the species remain largely unknown. The oxidative stress response is a mechanism used by all organisms to mitigate environmental stress by reducing oxygen radicals in the body, and comparing this mechanism between similar species can be useful for understanding how different species compete in aquatic environments. We compared oxidative stress biomarkers (lipid peroxidation [LPO] and catalase [CAT] activity) in mussels after exposure to 4 stressors (i.e., high densities, temperature, hypoxia, and polychlorinated biphenyls [PCBs]) independently and in combinations of 2 stressors. Overall, D. bugensis had lower LPO and CAT activity than D. polymorpha when exposed to single stressors; however, in multiple stressor treatments D. bugensis had increased LPO, especially with high temperatures and PCBs. The lower lipid damage in D. bugensis compared with D. polymorpha under single stressor conditions may come at the cost of the ability to respond to multiple stressors. Environ Toxicol Chem 2018;9999:1-12. © 2018 SETAC. © 2018 SETAC.

  3. Cost-effective IMTA: a comparison of the production efficiencies of mussels and seaweed

    DEFF Research Database (Denmark)

    Holdt, Susan Løvstad; Edwards, M. D.

    results compared to production cost of €209-672 kg-1 N removed and €1,013 kg-1 N removed for respectively Laminaria digitata and Alaria esculenta from extrapolated laboratory and field trials. However, a commercial seaweed (Saccharina latissima) producer claims that production costs are less than €10 kg-1...... N removed. This up-scaled and commercial figure makes the seaweed cost competitive to mussels for removal of nitrogen. Disadvantages such as predators (e.g. eider ducks) and bio-fouling should also be taken into account before choice of biofilter is made. These drawbacks can reduce overall biofilter...

  4. Rapid molecular detection of invasive species in ballast and harbor water by integrating environmental DNA and light transmission spectroscopy.

    Science.gov (United States)

    Egan, Scott P; Grey, Erin; Olds, Brett; Feder, Jeffery L; Ruggiero, Steven T; Tanner, Carol E; Lodge, David M

    2015-04-07

    Invasive species introduced via the ballast water of commercial ships cause enormous environmental and economic damage worldwide. Accurate monitoring for these often microscopic and morphologically indistinguishable species is challenging but critical for mitigating damages. We apply eDNA sampling, which involves the filtering and subsequent DNA extraction of microscopic bits of tissue suspended in water, to ballast and harbor water sampled during a commercial ship's 1400 km voyage through the North American Great Lakes. Using a lab-based gel electrophoresis assay and a rapid, field-ready light transmission spectroscopy (LTS) assay, we test for the presence of two invasive species: quagga (Dreissena bugensis) and zebra (D. polymorpha) mussels. Furthermore, we spiked a set of uninfested ballast and harbor samples with zebra mussel tissue to further test each assay's detection capabilities. In unmanipulated samples, zebra mussel was not detected, while quagga mussel was detected in all samples at a rate of 85% for the gel assay and 100% for the LTS assay. In the spiked experimental samples, both assays detected zebra mussel in 94% of spiked samples and 0% of negative controls. Overall, these results demonstrate that eDNA sampling is effective for monitoring ballast-mediated invasions and that LTS has the potential for rapid, field-based detection.

  5. A SEROLOGIC AND POLYMERASE CHAIN REACTION SURVEY OF EQUINE HERPESVIRUS IN BURCHELL'S ZEBRAS (EQUUS QUAGGA), HARTMANN'S MOUNTAIN ZEBRAS (EQUUS ZEBRA HARTMANNAE), AND THOMSON'S GAZELLES (EUDORCAS THOMSONII) IN A MIXED SPECIES SAVANNAH EXHIBIT.

    Science.gov (United States)

    Lopez, Karen M; Fleming, Gregory J; Mylniczenko, Natalie D

    2016-12-01

    Reports of equine herpesvirus (EHV) 1 and EHV-9 causing clinical disease in a wide range of species have been well documented in the literature. It is thought that zebras are the natural hosts of EHV-9 both in the wild and in captive collections. Concerns about potential interspecies transmission of EHV-1 and EHV-9 in a mixed species savannah exhibit prompted serologic and polymerase chain reaction surveys. Eighteen Burchell's zebras ( Equus quagga ), 11 Hartmann's mountain zebras ( Equus zebra hartmannae), and 14 Thomson's gazelles ( Eudorcas thomsonii ) cohabitating the same exhibit were examined for EHV-1 virus neutralization titers, and evidence of virus via EHV 1-5 polymerase chain reactions. None of the animals had previous exposure to vaccination with EHV-1 or EHV-4. All tested zebras had positive EHV-1 titers, ranging from 4 to 384. All zebras and Thomson's gazelles had negative polymerase chain reaction results for all targeted equine herpesviruses. EHV-9-specific assays are not available but EHV-1, EHV-4, and EHV-9 cross-react serologically. Positive serology results indicate a potential latent equine herpesvirus in the zebra population, which prompted initiation of an equine herpesvirus vaccine protocol, changes in pregnant zebra mare management, and equine herpesvirus polymerase chain reaction screening prior to shipment to or from the study site.

  6. Drag of Clean and Fouled Net Panels--Measurements and Parameterization of Fouling.

    Directory of Open Access Journals (Sweden)

    Lars Christian Gansel

    Full Text Available Biofouling is a serious problem in marine aquaculture and it has a number of negative impacts including increased forces on aquaculture structures and reduced water exchange across nets. This in turn affects the behavior of fish cages in waves and currents and has an impact on the water volume and quality inside net pens. Even though these negative effects are acknowledged by the research community and governmental institutions, there is limited knowledge about fouling related effects on the flow past nets, and more detailed investigations distinguishing between different fouling types have been called for. This study evaluates the effect of hydroids, an important fouling organism in Norwegian aquaculture, on the forces acting on net panels. Drag forces on clean and fouled nets were measured in a flume tank, and net solidity including effect of fouling were determined using image analysis. The relationship between net solidity and drag was assessed, and it was found that a solidity increase due to hydroids caused less additional drag than a similar increase caused by change in clean net parameters. For solidities tested in this study, the difference in drag force increase could be as high as 43% between fouled and clean nets with same solidity. The relationship between solidity and drag force is well described by exponential functions for clean as well as for fouled nets. A method is proposed to parameterize the effect of fouling in terms of an increase in net solidity. This allows existing numerical methods developed for clean nets to be used to model the effects of biofouling on nets. Measurements with other types of fouling can be added to build a database on effects of the accumulation of different fouling organisms on aquaculture nets.

  7. Mussels and Yachts in Loch Fyne, Scotland: a Case Study of the Science-Policy Interface

    Directory of Open Access Journals (Sweden)

    Paul Tett

    2012-09-01

    Full Text Available We report an application of the Science and Policy Integration for Coastal System Assessment (SPICOSA Systems Approach Framework (SAF to Loch Fyne, a fjord in western Scotland. The issue was the potential for conflict between shellfish aquaculture and recreational use for yachting. This was investigated by building an ecological-economic model to simulate: (1 release of modern anti-fouling compounds by recreational boats; (2 dilution of these in the upper layers of the loch by exchange with the sea; (3 their effects on photosynthesis by phytoplankton; (4 the role of phytoplankton (along with non-algal particulate matter in providing food for mussels; (5 the growth of seeded mussels to harvest, determining (6 the cash input to farms, offset by their costs and allowing (7 the farm revenue to be compared with that from marinas used to berth the yachts. It was concluded from simulations that no noticeable effect on mussel harvest would occur (from this route for any likely number of yachts berthed in the loch. The application took place in consultation with a local environmental forum and a small reference group of public officials; we reflect on it in the context of a 3-component schema for the science-policy interface and changes in the culture of UK science.

  8. Broad shifts in the resource use of a commercially harvested fish following the invasion of dreissenid mussels.

    Science.gov (United States)

    Fera, Shannon A; Rennie, Michael D; Dunlop, Erin S

    2017-06-01

    Dreissenid mussels, including the zebra (Dreissena polymorpha) and quagga (Dreissena rostiformus bugensis) mussel, are invasive species known for their capacity to act as ecosystem engineers. They have caused significant changes in the many freshwater systems they have invaded by increasing water clarity, reducing primary productivity, and altering zooplankton and benthic invertebrate assemblages. What is less clear is how their ecosystem engineering effects manifest up the food web to impact higher trophic levels, including fish. Here, we use a biological tracer (stable isotopes of carbon and nitrogen) to analyze long-term and broad-scale trends in the resource use of benthivorous lake whitefish (Coregonus clupeaformis) in the Laurentian Great Lakes, where dreissenid mussels have become established in each lake except Lake Superior. We measured stable isotope ratios from archived material (fish scale samples) collected over several decades by multiple agencies and from 14 locations around the Great Lakes. In the majority of locations, the δ 13 C of lake whitefish increased following the establishment of dreissenid mussels. Trends in δ 15 N were less clear, but significant breakpoints in the time series occurred within 5 yr of dreissenid establishment in several locations, followed by declines in δ 15 N. In contrast, isotopic signatures in Lake Superior locations did not show these trends. Our results provide evidence that lake whitefish shifted toward greater reliance on nearshore benthic production, supporting the theory that fundamental energy pathways are changed when dreissenid mussels become established. Importantly, these effects were noted across multiple, large, and complex ecosystems spanning a broad geographic area. Our study underscores the potential for aquatic invasive species to alter key ecosystem services as demonstrated here through their impacts on energy pathways supporting a commercially harvested fish species. © 2017 by the Ecological

  9. The role of shore crabs and mussel density in mussel losses at a commercial intertidal mussel plot after seeding

    NARCIS (Netherlands)

    Capelle, Jacob J.; Scheiberlich, Gerard; Wijsman, Jeroen W.M.; Smaal, Aad C.

    2016-01-01

    Mussel losses peak after relaying seed on culture plots. The present paper is an attempt to examine the role of shore crab predation and initial mussel density on mussel losses in mussel bottom culture using an intertidal culture plot as a case study. Because of their small size and loose

  10. Zebra: searching for rare diseases

    DEFF Research Database (Denmark)

    Dragusin, Radu; Petcu, Paula; Lioma, Christina

    2012-01-01

    disease diagnostic hypotheses in the domain of medical IR. In this work, we build upon an existing vertical medical search engine, Zebra, that is focused on rare disease diagnosis. In previous work, Zebra has been evaluated using real-life medical cases of rare and difficult diseases, and has been found...

  11. Macrofouling control in nuclear power plants

    International Nuclear Information System (INIS)

    Ekis, E.W. Jr.; Keoplin-Gall, S.M.; McCarthy, R.E.

    1991-01-01

    Macrofouling of cooling-water systems is one of the more significant and costly problems encountered in the nuclear power industry. Both marine and freshwater macroinvertebrates can be responsible for losses in plant availability because of plugged intakes and heat transfer equipment. There is a greater diversity of macrofouling organisms in marine waters than in fresh waters. Marine macrofouling organisms include barnacles, mollusks, bryozoans, and hydroids. Barnacles are crustaceans with feathery appendages, which allow them to attach to a variety of surfaces. They are a major cause of severe macrofouling because they can remain attached even after death. The major freshwater macrofouling organisms include the Asiatic Clam (Corbicula fluminea) and the newest freshwater macrofouler, the Zebra Mussel (Dreissena polymorpha). The introduction of the Zebra Mussel into the Great Lakes has created economic and ecological problems that will not easily be solved. The threat of intercontinental dispersal of the Zebra Mussel in America is serious. Research programs have been initiated around the country to develop control methods for this macrofouling problem. The various control methodologies can be classified in the following categories: biological, chemical, physical, and mechanical. Laboratory experiments were performed to evaluate the efficacy of Actibrom against mature Zebra Mussels

  12. Stable isotopes of nitrogen and carbon in an aquatic food web recently invaded by Dreissena polymorpha (Pallas)

    International Nuclear Information System (INIS)

    Mitchell, M.J.; Mills, E.L.; Idrisi, N.; Michener, R.

    1996-01-01

    The carbon and nitrogen concentrations and the stable isotopic compositions (δ 13 C and δ 15 N) of major abiotic and biotic constituents were determined in Oneida Lake, New York. This lake was invaded by the zebra mussel (Dreissena polymorpha) in 1990 and there have been concomitant changes in various biotic and abiotic lake properties. The C (46-49%) and N (12%) concentrations and C:N ratios (3.9-4) of zebra mussel flesh were similar to those reported for other lakes. Trophic positions were reflected in the δ 15 N values for which walleye > gizzard shad and yellow perch > Daphnia spp. and zebra mussel flesh > seston and sediment. There was an average increase of 3.6% 0 15 N per trophic transfer. Results from the δ 13 C analysis suggest that Daphnia spp. were using a distinct source of organic carbon whereas zebra mussel were using the entire seston resource. Only yellow perch showed a significant shift in δ 13 C values (1.1% 0 ), possibly reflecting a shift in a food source and diet from 1992 to 1993. (author). 48 refs., 2 tabs., 2 figs

  13. Proceedings: Condenser technology conference

    International Nuclear Information System (INIS)

    Tsou, J.L.; Mussalli, Y.G.

    1991-08-01

    Seam surface condenser and associated systems performance strongly affects availability and heat rate in nuclear and fossil power plants. Thirty-six papers presented at a 1990 conference discuss research results, industry experience, and case histories of condenser problems and solutions. This report contains papers on life extension, performance improvement, corrosion and failure analysis, fouling prevention, and recommendation for future R ampersand D. The information represents recent work on condenser problems and solutions to improve the procurement, operation, and maintenance functions of power plant personnel. Several key points follow: A nuclear and a fossil power plant report show that replacing titanium tube bundles improves condenser availability and performance. One paper reports 10 years of experience with enhanced heat transfer tubes in utility condensers. The newly developed enhanced condenser tubes could further improve condensing heat transfer. A new resistance summation method improves the accuracy of condenser performance prediction, especially for stainless steel and titanium tubed condensers. Several papers describe improved condenser fouling monitoring techniques, including a review of zebra mussel issues

  14. Placentation in the plains zebra (Equus quagga).

    Science.gov (United States)

    Allen, W R Twink; Stansfield, Fiona; Wilsher, Sandra

    2017-10-01

    The placenta and fetal gonads of 12 pregnant plains zebra (Equus quagga), estimated to be between 81 and 239 days of gestation, were examined. The diffuse, microcotyledonary zebra placenta appeared, developmentally, to be 3-4 weeks behind its counterpart in horse pregnancy and this, together with the presence of small and long-lived endometrial cups, low levels of zebra chorionic gonadotrophin in maternal serum and few accessory corpora lutea in the maternal ovaries during the first half of gestation, made zebra pregnancy more similar to donkey than horse pregnancy. Zebra fetal gonads enlarged after 80 days of gestation and their interstitial cells stained positively for 3β hydroxysteroid dehydrogenase and 17,20 lyase steroid enzymes while the trophoblast stained for aromatase. This confirmed that zebra fetal gonads, like those of the horse and donkey, can synthesise C19 androgens, which can then be aromatised by the placenta to C18 oestrogens. It is remarkable that such unusual feto-placental mechanisms of production of gonadotrophic and steroid hormones has persisted unchanged within the genus Equus despite the many physical adaptations and the considerable loss of chromosomes that have occurred during the evolution of its member species.

  15. Zebra: A striped network file system

    Science.gov (United States)

    Hartman, John H.; Ousterhout, John K.

    1992-01-01

    The design of Zebra, a striped network file system, is presented. Zebra applies ideas from log-structured file system (LFS) and RAID research to network file systems, resulting in a network file system that has scalable performance, uses its servers efficiently even when its applications are using small files, and provides high availability. Zebra stripes file data across multiple servers, so that the file transfer rate is not limited by the performance of a single server. High availability is achieved by maintaining parity information for the file system. If a server fails its contents can be reconstructed using the contents of the remaining servers and the parity information. Zebra differs from existing striped file systems in the way it stripes file data: Zebra does not stripe on a per-file basis; instead it stripes the stream of bytes written by each client. Clients write to the servers in units called stripe fragments, which are analogous to segments in an LFS. Stripe fragments contain file blocks that were written recently, without regard to which file they belong. This method of striping has numerous advantages over per-file striping, including increased server efficiency, efficient parity computation, and elimination of parity update.

  16. Ecotoxicological impact of Zequanox®, a novel biocide, on selected non-target Irish aquatic species.

    Science.gov (United States)

    Meehan, Sara; Shannon, Adam; Gruber, Bridget; Rackl, Sarahann M; Lucy, Frances E

    2014-09-01

    Effective, species-specific zebra mussel control is needed urgently for Ireland׳s freshwater bodies, which became infested with non-native zebra mussels in the 1990s. Zequanox®, a newly commercialized product for zebra and quagga mussel control, is composed of dead Pseudomonas fluorescens CL 145A cells. This paper describes ecotoxicology tests on three representative native Irish freshwater species: Anodonta (duck mussel), Chironomus plumosus (non-biting midge), and Austropotamobius pallipes (white-clawed crayfish). The species were exposed to Zequanox in a 72-h static renewal toxicity test at concentrations of 100-750mg active ingredient per liter (mga.i./L). Water quality parameters were measured every 12-24h before and after water and product renewal. After 72h, endpoints were reported as LC10, LC50, and LC100. The LC50 values derived were (1) Anodonta: ≥500mga.i./L (2) C. plumosus: 1075mga.i./L, and (3) A. pallipes: ≥750mga.i./L. These results demonstrate that Zequanox does not negatively affect these organisms at the concentration required for >80percent zebra mussel mortality (150mg a.i/L) and the maximum allowable treatment concentration in the United Sates (200mga.i./L). They also show the overall species-specificity of Zequanox, and support its use in commercial facilities and open waters. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Autoradiographic study on the distribution of 241Am in the shell of the freshwater zebra mussel Dreissena polymorpha

    International Nuclear Information System (INIS)

    Zuykov, M.; Pelletier, E.; Rouleau, C.; Popov, L.; Fowler, S.W.; Orlova, M.

    2009-01-01

    Autoradiography was used to identify α-track distributions in a series of shell sections from live mussels Dreissena polymorpha Pallas and dissected shells of dead mussels obtained from laboratory experiments using relatively high concentrations of 241 Am in the exposure media, a required condition for successful use of this autoradiographic technique. A comparable distribution of α-tracks was recorded on autoradiographs from both live and dead shells suggesting that metabolism does not lead to any sizable changes in the process of 241 Am adsorption (present in the extrapallial fluid) onto the inner surface of shell. Autoradiographs showed a preferential accumulation of 241 Am in the organic periostracum, whereas the outer and inner shell layers were characterized by a relatively low α-tracks density. No α-tracks were observed in the central part of the shell in any of the samples. These observations will be useful for the development of a general model to explain bioaccumulation and biosorption processes of radionuclides into mollusk shells. (author)

  18. A Probability Co-Kriging Model to Account for Reporting Bias and Recognize Areas at High Risk for Zebra Mussels and Eurasian Watermilfoil Invasions in Minnesota

    Directory of Open Access Journals (Sweden)

    Kaushi S. T. Kanankege

    2018-01-01

    Full Text Available Zebra mussels (ZMs (Dreissena polymorpha and Eurasian watermilfoil (EWM (Myriophyllum spicatum are aggressive aquatic invasive species posing a conservation burden on Minnesota. Recognizing areas at high risk for invasion is a prerequisite for the implementation of risk-based prevention and mitigation management strategies. The early detection of invasion has been challenging, due in part to the imperfect observation process of invasions including the absence of a surveillance program, reliance on public reporting, and limited resource availability, which results in reporting bias. To predict the areas at high risk for invasions, while accounting for underreporting, we combined network analysis and probability co-kriging to estimate the risk of ZM and EWM invasions. We used network analysis to generate a waterbody-specific variable representing boater traffic, a known high risk activity for human-mediated transportation of invasive species. In addition, co-kriging was used to estimate the probability of species introduction, using waterbody-specific variables. A co-kriging model containing distance to the nearest ZM infested location, boater traffic, and road access was used to recognize the areas at high risk for ZM invasions (AUC = 0.78. The EWM co-kriging model included distance to the nearest EWM infested location, boater traffic, and connectivity to infested waterbodies (AUC = 0.76. Results suggested that, by 2015, nearly 20% of the waterbodies in Minnesota were at high risk of ZM (12.45% or EWM (12.43% invasions, whereas only 125/18,411 (0.67% and 304/18,411 (1.65% are currently infested, respectively. Prediction methods presented here can support decisions related to solving the problems of imperfect detection, which subsequently improve the early detection of biological invasions.

  19. A Probability Co-Kriging Model to Account for Reporting Bias and Recognize Areas at High Risk for Zebra Mussels and Eurasian Watermilfoil Invasions in Minnesota.

    Science.gov (United States)

    Kanankege, Kaushi S T; Alkhamis, Moh A; Phelps, Nicholas B D; Perez, Andres M

    2017-01-01

    Zebra mussels (ZMs) ( Dreissena polymorpha ) and Eurasian watermilfoil (EWM) ( Myriophyllum spicatum ) are aggressive aquatic invasive species posing a conservation burden on Minnesota. Recognizing areas at high risk for invasion is a prerequisite for the implementation of risk-based prevention and mitigation management strategies. The early detection of invasion has been challenging, due in part to the imperfect observation process of invasions including the absence of a surveillance program, reliance on public reporting, and limited resource availability, which results in reporting bias. To predict the areas at high risk for invasions, while accounting for underreporting, we combined network analysis and probability co-kriging to estimate the risk of ZM and EWM invasions. We used network analysis to generate a waterbody-specific variable representing boater traffic, a known high risk activity for human-mediated transportation of invasive species. In addition, co-kriging was used to estimate the probability of species introduction, using waterbody-specific variables. A co-kriging model containing distance to the nearest ZM infested location, boater traffic, and road access was used to recognize the areas at high risk for ZM invasions (AUC = 0.78). The EWM co-kriging model included distance to the nearest EWM infested location, boater traffic, and connectivity to infested waterbodies (AUC = 0.76). Results suggested that, by 2015, nearly 20% of the waterbodies in Minnesota were at high risk of ZM (12.45%) or EWM (12.43%) invasions, whereas only 125/18,411 (0.67%) and 304/18,411 (1.65%) are currently infested, respectively. Prediction methods presented here can support decisions related to solving the problems of imperfect detection, which subsequently improve the early detection of biological invasions.

  20. Antifouling Activity towards Mussel by Small-Molecule Compounds from a Strain of Vibrio alginolyticus Bacterium Associated with Sea Anemone Haliplanella sp.

    Science.gov (United States)

    Wang, Xiang; Huang, Yanqiu; Sheng, Yanqing; Su, Pei; Qiu, Yan; Ke, Caihuan; Feng, Danqing

    2017-03-28

    Mussels are major fouling organisms causing serious technical and economic problems. In this study, antifouling activity towards mussel was found in three compounds isolated from a marine bacterium associated with the sea anemone Haliplanella sp. This bacterial strain, called PE2, was identified as Vibrio alginolyticus using morphology, biochemical tests, and phylogenetic analysis based on sequences of 16S rRNA and four housekeeping genes ( rpoD, gyrB, rctB, and toxR ). Three small-molecule compounds (indole, 3-formylindole, and cyclo (Pro-Leu)) were purified from the ethyl acetate extract of V. alginolyticus PE2 using column chromatography techniques. They all significantly inhibited byssal thread production of the green mussel Perna viridis , with EC 50 values of 24.45 μg/ml for indole, 50.07 μg/ml for 3-formylindole, and 49.24 μg/ml for cyclo (Pro-Leu). Previous research on the antifouling activity of metabolites from marine bacteria towards mussels is scarce. Indole, 3-formylindole and cyclo (Pro-Leu) also exhibited antifouling activity against settlement of the barnacle Balanus albicostatus (EC 50 values of 8.84, 0.43, and 11.35 μg/ml, respectively) and the marine bacterium Pseudomonas sp. (EC 50 values of 42.68, 69.68, and 39.05 μg/ml, respectively). These results suggested that the three compounds are potentially useful for environmentally friendly mussel control and/or the development of new antifouling additives that are effective against several biofoulers.

  1. Shell-free biomass and population dynamics of dreissenids in offshore Lake Michigan, 2001-2003

    Science.gov (United States)

    French, J. R. P.; Adams, J.V.; Craig, J.; Stickel, R.G.; Nichols, S.J.; Fleischer, G.W.

    2007-01-01

    The USGS-Great Lakes Science Center has collected dreissenid mussels annually from Lake Michigan since zebra mussels (Dreissena polymorpha) became a significant portion of the bottom-trawl catch in 1999. For this study, we investigated dreissenid distribution, body mass, and recruitment at different depths in Lake Michigan during 2001-2003. The highest densities of dreissenid biomass were observed from depths of 27 to 46 m. The biomass of quagga mussels (Dreissena bugensis) increased exponentially during 2001-2003, while that of zebra mussels did not change significantly. Body mass (standardized for a given shell length) of both species was lowest from depths of 27 to 37m, highest from 55 to 64 m, and declined linearly at deeper depths during 2001-2003. Recruitment in 2003, as characterized by the proportion of mussels biomass in Lake Michigan.

  2. Preparation and properties of silicone fouling release coatings with long-life afterglow fluorescent

    Directory of Open Access Journals (Sweden)

    Zhang Zhanping

    2017-01-01

    Full Text Available Based on polydimethylsiloxane, three-component coatings were prepared with different content of luminescence powder. The results showed that the illuminance of coatings increases with the content of luminescence powder, decays exponentially with the afterglow time, increases exponentially with the increase of exposure time. The afterglow illuminance augments with irradiated light illuminance. All coatings are hydrophobic and oleophilic. Surface free energy decreases with the increase of luminescence powder. They have highest impact-resistance and bend flexibility. The luminescence powder does not change obviously the shore hardness, tensile breaking strength, breaking elongation rate, elastic modular and roughness of coatings. The static test panels in sea generally could be covered obviously by biofouling including sponges, bryophytes and mussels, hydra, kelp, green algae after 2 months of immersion during growing season. But it never found that the barnacle attached on the coating surface during 4 years of immersion test. The static anti-fouling ability of the coatings is very limited. In addition, the sea creatures attached on the coating surface can be easily removed; even attached organisms will fall off and expose again the smooth coating surface. Consequently, all coatings with long-life afterglow fluorescent have a significant effect on preventing adhesion of barnacle and fouling-release performance.

  3. The Dreissena-monitor - studies on the behaviour of the zebra mussel in the river Rhine - valuation of accidental spills in the continuous monitoring of water quality

    International Nuclear Information System (INIS)

    Borcherding, J.; Volpers, M.

    1994-01-01

    The Dreissena-Monitor is a biological early warning system using the native freshwater mussel Dreissena polymorpha. A computer analyzed the opening status and the number of valve movements of 42 mussels exposed in each of two experimental channels. (orig.) [de

  4. Chemical analysis and genotoxicity of high molecular mass PAH in sediment samples and biota

    International Nuclear Information System (INIS)

    McCarry, B.E.; Marvin, C.H.; Smith, R.W.; Bryant, D.W.

    1995-01-01

    A normal phase liquid chromatography (NPLC) method was used to fractionate the organic extracts of prepared from coal tar-contaminated sediments from hamilton Harbor in Ontario and from Sydney Harbor in Nova Scotia into molecular mass classes. Each PAH fraction up to 302 amu was analyzed by GC-MS and fractions containing PAH with molecular masses greater than 302 amu were analyzed by atmospheric pressure chemical ionization (APCI) LC-MS.Each fraction was also subjected to Ames bioassays using a TA100-like strain of Salmonella typhimurium (YG1025 + S9). The 300/302 amu, 326/328 and 350/352 amu PAH fractions accounted for 25% of the total genotoxic response of the extract; these PAH constitute a substantial genotoxic burden. A number of 300, 302, 326, 350, 374 and 400 amu PAH were identified using APCI LC-MS and comparison with authentic standards. The non-polar aromatic extracts of bottom sediments, suspended sediments and zebra mussels from Hamilton Harbor were also examined by GC-MS, APCI LC-MS and genotoxicity bioassays. The profiles of the priority and high mass PAH in these samples were identical showing that all PAH up to and exceeding 400 amu were readily bioavailable to biota such as Zebra mussels. In addition, the pseudo faeces of the Zebra mussels and amphipod detritivores which fed on the pseudo faeces had chemical profiles identical to the Zebra mussels. Since many sport fish prize amphipods as food, this observation demonstrates a pathway for organic contaminants adsorbed to suspended sediments to enter the food chain of non-bottom-feeding fish in areas infested by Zebra mussels

  5. A direct biocombinatorial strategy toward next generation, mussel-glue inspired saltwater adhesives.

    Science.gov (United States)

    Wilke, Patrick; Helfricht, Nicolas; Mark, Andreas; Papastavrou, Georg; Faivre, Damien; Börner, Hans G

    2014-09-10

    Biological materials exhibit remarkable, purpose-adapted properties that provide a source of inspiration for designing new materials to meet the requirements of future applications. For instance, marine mussels are able to attach to a broad spectrum of hard surfaces under hostile conditions. Controlling wet-adhesion of synthetic macromolecules by analogue processes promises to strongly impact materials sciences by offering advanced coatings, adhesives, and glues. The de novo design of macromolecules to mimic complex aspects of mussel adhesion still constitutes a challenge. Phage display allows material scientists to design specifically interacting molecules with tailored affinity to material surfaces. Here, we report on the integration of enzymatic processing steps into phage display biopanning to expand the biocombinatorial procedure and enable the direct selection of enzymatically activable peptide adhesion domains. Adsorption isotherms and single molecule force spectroscopy show that those de novo peptides mimic complex aspects of bioadhesion, such as enzymatic activation (by tyrosinase), the switchability from weak to strong binders, and adsorption under hostile saltwater conditions. Furthermore, peptide-poly(ethylene oxide) conjugates are synthesized to generate protective coatings, which possess anti-fouling properties and suppress irreversible interactions with blood-plasma protein cocktails. The extended phage display procedure provides a generic way to non-natural peptide adhesion domains, which not only mimic nature but also improve biological sequence sections extractable from mussel-glue proteins. The de novo peptides manage to combine several tasks in a minimal 12-mer sequence and thus pave the way to overcome major challenges of technical wet glues.

  6. Modeling the effect of water chemistry on the bioaccumulation of waterborne cadmium in zebra mussels.

    Science.gov (United States)

    Bourgeault, Adeline; Gourlay-Francé, Catherine; Tusseau-Vuillemin, Marie-Hélène

    2010-10-01

    The present study aims at investigating the effects of Zn, Ca, and dissolved organic carbon (DOC) on the waterborne Cd bioaccumulation of a freshwater bivalve (Dreissena polymorpha). Mussels were exposed for 48 h at 3 µg/L of Cd in different media. Their physiological activities were assessed by separately measuring the filtration rate in the same exposure water. Increased Zn (from 3 to 89 µg/L) and Ca (from 37 to 131 mg/L) concentrations in water led to a threefold and sevenfold reduction of Cd bioaccumulation, whereas the effect of DOC varied greatly depending on its concentration. At low DOC concentrations (from 0.2 to 1.1 mg/L), the uptake of Cd increased, whereas at higher concentrations (from 1.1 to 17.1 mg/L), the uptake decreased. The filtration activity was not strongly influenced by either Zn or Ca concentration, whereas it was modified in enriched DOC media in the same manner as Cd uptake. A competitive model was built to predict the waterborne uptake rate constant of Cd (k (u)) as a function of Zn and Ca concentrations in the water. Over the range of DOC concentrations we tested, organic matter was shown to influence Cd bioaccumulation in two ways: by modifying Cd speciation and thus its bioavailability and its interaction with the biological membrane, and by affecting the mussel's physiology and therefore its sensitivity to metal. The present study provides a useful means of adjusting the toxicokinetic constant to the water's physicochemical characteristics and proposes a unifying model that takes into account the different geochemical and biological influences on bioaccumulation. Environ. Toxicol. Chem. 2010;29:2182-2189. © 2010 SETAC.

  7. Quantifying quagga mussel veliger abundance and distribution in Copper Basin Reservoir (California) using acoustic backscatter.

    Science.gov (United States)

    Anderson, Michael A; Taylor, William D

    2011-11-01

    Quagga mussels (Dreissena bugensis) have been linked to oligotrophication of lakes, alteration of aquatic food webs, and fouling of infrastructure associated with water supply and power generation, causing potentially billions of dollars in direct and indirect damages. Understanding their abundance and distribution is key in slowing their advance, assessing their potential impacts, and evaluating effectiveness of control strategies. Volume backscatter strength (Sv) measurements at 201- and 430-kHz were compared with quagga mussel veliger and zooplankton abundances determined from samples collected using a Wisconsin closing net from the Copper Basin Reservoir on the Colorado River Aqueduct. The plankton within the lower portion of the water column (>18 m depth) was strongly dominated by D-shaped quagga mussel veligers, comprising up to 95-99% of the community, and allowed direct empirical measurement of their mean backscattering cross-section. The upper 0-18 m of the water column contained a smaller relative proportion of veligers based upon net sampling. The difference in mean volume backscatter strength at these two frequencies was found to decrease with decreasing zooplankton abundance (r(2) = 0.94), allowing for correction of Sv due to the contribution of zooplankton and the determination of veliger abundance in the reservoir. Hydroacoustic measurements revealed veligers were often present at high abundances (up to 100-200 ind L(-1)) in a thin 1-2 m layer at the thermocline, with considerable patchiness in their distribution observed along a 700 m transect on the reservoir. Under suitable conditions, hydroacoustic measurements can rapidly provide detailed information on the abundance and distribution of quagga mussel veligers over large areas with high horizontal and vertical resolution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. CA/CPS: A Communications ZEBRA implementation using CPS

    International Nuclear Information System (INIS)

    Roberts, L.A.

    1991-05-01

    CZ/CPS is an implementation of the Communications ZEBRA distributed computing environment utilizing the CPS communications protocol. CZ/CPS is intended for parallelization of high energy physics application programs using the CERN Program Library memory and data structure management features. CZ/CPS provides transparent communication of ZEBRA data structures among cooperative processes using standard interfaces for ZEBRA I/O. Examples of usage in a CPS HBOOK4 and GEANT3 application are provided

  9. In situ and laboratory bioassays to evaluate the impact of effluent discharges on receiving aquatic ecosystems

    International Nuclear Information System (INIS)

    Smolders, R.; Bervoets, L.; Blust, R.

    2004-01-01

    Effluents are a main source of direct and often continuous input of pollutants into aquatic ecosystems with long-term implications on ecosystem functioning. Therefore, the study of the effects of effluent exposure on organisms, populations or communities within the framework of impact assessment has a high ecological relevance. The aim of this study was to assess the toxicological impact of two effluents, one household wastewater treatment effluent (Effluent 1) and one industrial effluent (Effluent 2), on the receiving aquatic ecosystem using two test species under both in situ and laboratory conditions. Zebra mussel (Dreissena polymorpha) and common carp (Cyprinus carpio) were exposed under laboratory conditions in an online monitoring flow-through system (receiving different concentrations of Effluent 2) and under in situ conditions along the pollution gradient established by these two effluent discharges. Bioassays focussed on growth and condition related endpoints (i.e. condition, growth, lipid budget), since these are key functional processes within organisms and populations. Under laboratory conditions, increasing concentrations of the industrial effluent (Effluent 2) had a negative effect on both zebra mussel and carp energy reserves and condition. Under in situ conditions, the same negative impact of Effluent 2 was observed for zebra mussels, while Effluent 1 had no apparent effect on exposed zebra mussels. Carp growth and condition, on the other hand, were significantly increased at the discharge sites of both effluents when compared to the reference site, probably due to differences in food availability. The results indicate that a combination of in situ and laboratory exposures can illustrate how ecological processes influence bioassay studies. The incorporation of indirect, ecological effects, like changes in food availability, provides considerable benefit in understanding and predicting effects of effluents on selected species under realistic exposure

  10. In situ and laboratory bioassays to evaluate the impact of effluent discharges on receiving aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Smolders, R. [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: roel.smolders@ua.ac.be; Bervoets, L. [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Blust, R. [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2004-11-01

    Effluents are a main source of direct and often continuous input of pollutants into aquatic ecosystems with long-term implications on ecosystem functioning. Therefore, the study of the effects of effluent exposure on organisms, populations or communities within the framework of impact assessment has a high ecological relevance. The aim of this study was to assess the toxicological impact of two effluents, one household wastewater treatment effluent (Effluent 1) and one industrial effluent (Effluent 2), on the receiving aquatic ecosystem using two test species under both in situ and laboratory conditions. Zebra mussel (Dreissena polymorpha) and common carp (Cyprinus carpio) were exposed under laboratory conditions in an online monitoring flow-through system (receiving different concentrations of Effluent 2) and under in situ conditions along the pollution gradient established by these two effluent discharges. Bioassays focussed on growth and condition related endpoints (i.e. condition, growth, lipid budget), since these are key functional processes within organisms and populations. Under laboratory conditions, increasing concentrations of the industrial effluent (Effluent 2) had a negative effect on both zebra mussel and carp energy reserves and condition. Under in situ conditions, the same negative impact of Effluent 2 was observed for zebra mussels, while Effluent 1 had no apparent effect on exposed zebra mussels. Carp growth and condition, on the other hand, were significantly increased at the discharge sites of both effluents when compared to the reference site, probably due to differences in food availability. The results indicate that a combination of in situ and laboratory exposures can illustrate how ecological processes influence bioassay studies. The incorporation of indirect, ecological effects, like changes in food availability, provides considerable benefit in understanding and predicting effects of effluents on selected species under realistic exposure

  11. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran; Vuong, Francois; Hu, Jingyi; Li, Sheng; Kemperman, Antoine J.B.; Nijmeijer, Kitty; Cornelissen, Emile R.; Heijman, Sebastiaan G.J.; Rietveld, Luuk C.

    2015-01-01

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  12. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran

    2015-05-06

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  13. The Modified Fouling Index Ultrafiltration constant flux for assessing particulate/colloidal fouling of RO systems

    KAUST Repository

    Salinas-Rodriguez, Sergio G.

    2015-02-18

    Reliable methods for measuring and predicting the fouling potential of reverse osmosis (RO) feed water are important in preventing and diagnosing fouling at the design stage, and for monitoring pre-treatment performance during plant operation. The Modified Fouling Index Ultrafiltration (MFI-UF) constant flux is a significant development with respect to assessing the fouling potential of RO feed water. This research investigates (1) the variables influencing the MFI-UF test at constant flux filtration (membrane pore size, membrane material, flux rate); and (2) the application of MFI-UF into pre-treatment assessment and RO fouling estimation. The dependency of MFI on flux, means that to assess accurately particulate fouling in RO systems, the MFI should be measured at a flux similar to a RO system (close to 20 L/m2/h) or extrapolated from higher fluxes. The two studied membrane materials showed reproducible results; 10% for PES membranes and 6.3% for RC membranes. Deposition factors (amount of particles that remain on the surface of membrane) were measured in a full-scale plant ranging between 0.2 and 0.5. The concept of “safe MFI” is presented as a guideline for assessing pre-treatment for RO systems.

  14. CONCENTRIC TUBE-FOULING RIG FOR INVESTIGATION OF FOULING DEPOSIT FORMATION FROM PASTEURISER OF VISCOUS FOOD LIQUID

    Directory of Open Access Journals (Sweden)

    N. I. KHALID

    2013-02-01

    Full Text Available This paper reports the work on developing concentric tube-fouling rig, a new fouling deposit monitoring device. This device can detect and quantify the level of fouling deposit formation. It can also functioning as sampler for fouling deposit study, which can be attached at any food processing equipment. The design is initiated with conceptual design. The rig is designed with inner diameter of 7 cm and with tube length of 37 cm. A spiral insert with 34.5 cm length and with 5.4 cm diameter is fitted inside the tube to ensure the fluid flows around the tube. In this work, the rig is attached to the lab-scale concentric tube-pasteurizer to test its effectiveness and to collect a fouling sample after pasteurization of pink guava puree. Temperature changes are recorded during the pasteurization and the data is used to plot the heat transfer profile. Thickness of the fouling deposit is also measured. The trends for thickness, heat resistance profile and heat transfer profile for concentric tube-fouling rig matched the trends obtained from lab-scale concentric tube-pasteurizer very well. The findings from this work have shown a good potential of this rig however there is a limitation with spiral insert, which is discussed in this paper.

  15. An indirect effect of biological invasions: the effect of zebra mussel fouling on parasitisation of unionid mussels by bitterling fish

    Czech Academy of Sciences Publication Activity Database

    Vrtílek, Milan; Reichard, Martin

    2012-01-01

    Roč. 696, č. 1 (2012), s. 205-214 ISSN 0018-8158 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Non-native species * Coevolution * Invasional meltdown * Host-parasite relationship * Aquatic ecosystems Subject RIV: EG - Zoology Impact factor: 1.985, year: 2012

  16. Aggregation and attachment responses of blue mussels, Mytilus edulis—impact of substrate composition, time scale and source of mussel seed

    DEFF Research Database (Denmark)

    Christensen, Helle Torp; Dolmer, Per; Hansen, Benni Winding

    2015-01-01

    to an optimization of the production. The effect of substrate composition and timing of formation of a mussel bed in relation to aggregation and attachment of mussels were investigated with mussel seeds obtained from two different sources: mussel seed dredged from a natural mussel bed and mussel seed collected from......Survival after transplantation of mussel seeds is crucial for the production output of blue mussels (Mytilus edulis L.) in bottom cultures. Hence, an understanding of the interactions between bed formation, habitat structure and performance of mussel seed of different origins can contribute...... showed that complex substrate indeed had a stabilizing effect on the mussel structure resulting in less aggregation and increased attachment strength. The 3D matrix forming a mussel bed was achieved faster on complex substrate, and led to reduced mortality of transplanted mussels. Despite significantly...

  17. FindZebra: a search engine for rare diseases.

    Science.gov (United States)

    Dragusin, Radu; Petcu, Paula; Lioma, Christina; Larsen, Birger; Jørgensen, Henrik L; Cox, Ingemar J; Hansen, Lars Kai; Ingwersen, Peter; Winther, Ole

    2013-06-01

    The web has become a primary information resource about illnesses and treatments for both medical and non-medical users. Standard web search is by far the most common interface to this information. It is therefore of interest to find out how well web search engines work for diagnostic queries and what factors contribute to successes and failures. Among diseases, rare (or orphan) diseases represent an especially challenging and thus interesting class to diagnose as each is rare, diverse in symptoms and usually has scattered resources associated with it. We design an evaluation approach for web search engines for rare disease diagnosis which includes 56 real life diagnostic cases, performance measures, information resources and guidelines for customising Google Search to this task. In addition, we introduce FindZebra, a specialized (vertical) rare disease search engine. FindZebra is powered by open source search technology and uses curated freely available online medical information. FindZebra outperforms Google Search in both default set-up and customised to the resources used by FindZebra. We extend FindZebra with specialized functionalities exploiting medical ontological information and UMLS medical concepts to demonstrate different ways of displaying the retrieved results to medical experts. Our results indicate that a specialized search engine can improve the diagnostic quality without compromising the ease of use of the currently widely popular standard web search. The proposed evaluation approach can be valuable for future development and benchmarking. The FindZebra search engine is available at http://www.findzebra.com/. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. 49 CFR 214.323 - Foul time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foul time. 214.323 Section 214.323 Transportation... TRANSPORTATION RAILROAD WORKPLACE SAFETY Roadway Worker Protection § 214.323 Foul time. Working limits established on controlled track through the use of foul time procedures shall comply with the following...

  19. Novel graphical approach as fouling pinch for increasing fouling formation period in heat exchanger network (HEN) state of the art

    International Nuclear Information System (INIS)

    Azad, Abazar Vahdat; Ghaebi, Hadi; Amidpour, Majid

    2011-01-01

    In this paper a new graphical tool is proposed for investigation of fouling formation period in heat exchanger networks (HEN). The objective of this paper is increasing the time that HEN can perform its desirable heat transfer operation without required cleaning process. In a typical heat exchanger network, fouling formation rate of some streams is more than other ones. The method obtained in this work is based on given more opportunity for fouling formation for streams with high fouling formation rate. In fact high fouling formation rate streams are replaced with low fouling formation rate streams between different heat exchangers so that more fouling formation opportunity may be given for HEN. Therefore the HEN cleaning time decreases in fixed time period and the high fouling formation streams should pass from the path that the low fouling formation rate stream previously has passed, and inversely. As a result, secondly stream with high fouling formation rate mixes with residues of primary stream (low fouling formation rate stream). Therefore we should consider to adoption and conformability of streams structures (for prevention of streams destruction) and thermal considerations (for desirable heat transfer). Outlet temperatures of hot and cold streams should state in predefined temperatures. For satisfying thermal consideration after streams replacement this approach can be used in plants that cleanliness and its operational costs are most important problem.

  20. Sublethal effects of a chlorinated and heated effluent on the physiology of the mussel, Mytilus edulis L.: A reduction in fitness for survival?

    International Nuclear Information System (INIS)

    Mazik, Krysia; Hitchman, Natasha; Quintino, Victor; Taylor, Colin J.L.; Butterfield, Jonathan; Elliott, Michael

    2013-01-01

    Highlights: • The impact of chlorinated cooling water effluent on Scope for Growth was assessed. • Scope for Growth in mussels was reduced after exposure to effluent in the field. • Scope for Growth was reduced along an exposure gradient, most notably in summer. • Body condition and reproductive condition decreased along a gradient of exposure. • Negative physiological effects were contained within a 1 km radius of the discharge. -- Abstract: Coastal power stations entrain large volumes of cooling water, requiring biocidal treatment to prevent biological fouling. Discharged effluent is both heated and contaminated with residual traces of biocide and so it is necessary to quantify the impacts of this discharge. Cooling water from Heysham 2 nuclear power station, NW England, UK, is discharged to the intertidal area, via a culvert (to minimise erosion and maximise dilution and dispersion by directing the effluent into the receiving water at all states of the tide) within which the effluent is contained at low water. The culvert and surrounding coastal area support a population of blue mussels (Mytilus edulis). Mussel health was determined along a gradient of exposure, using three physiological indices: Scope for Growth, Gonad Mantle Index and Somatic Condition Index (K Factor). The Mussels within the culvert exhibited reduced physiological index values compared to an external site. A trend was identified down the length of the culvert, representing a gradient of exposure and indicating a potential negative effect on growth and reproductive output

  1. Cheating the Locals: Invasive Mussels Steal and Benefit from the Cooling Effect of Indigenous Mussels.

    Directory of Open Access Journals (Sweden)

    Justin A Lathlean

    Full Text Available The indigenous South African mussel Perna perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. perna for collective thermoregulation. We investigated whether varying densities of P. perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. perna. This may have significant implications for predicting how the co-existence of

  2. Mussel Shell Impaction in the Esophagus

    Directory of Open Access Journals (Sweden)

    Sunmin Kim

    2013-03-01

    Full Text Available Mussels are commonly used in cooking around the world. The mussel shell breaks more easily than other shells, and the edge of the broken mussel shell is sharp. Impaction can ultimately cause erosion, perforation and fistula. Aside from these complications, the pain can be very intense. Therefore, it is essential to verify and remove the shell as soon as possible. In this report we describe the process of diagnosing and treating mussel shell impaction in the esophagus. Physicians can overlook this unusual foreign body impaction due to lack of experience. When physicians encounter a patient with severe chest pain after a meal with mussels, mussel shell impaction should be considered when diagnosing and treating the patient.

  3. Current research and development of controlling membrane fouling ...

    African Journals Online (AJOL)

    Fouling is a major problem influencing the operational performance, stability and cost of a membrane bioreactor (MBR). The composition of wastewater and biomass grown in the MBR are directly related to fouling. Many factors including operational parameters can affect the fouling process. The extent of fouling can be ...

  4. Presumptive red maple (Acer rubrum) toxicosis in Grevy's zebra (Equus grevyi).

    Science.gov (United States)

    Weber, M; Miller, R E

    1997-03-01

    Two female Grevy's zebras (Equus grevyi), one juvenile and one adult, were treated for hemolytic anemia. The juvenile survived, but the adult animal, which also had methemoglobinemia, was euthanized after it failed to recover from anesthesia. Significant pathologic findings in the adult zebra included generalized icterus, hemoglobinuric nephrosis, and paracentral hepatic necrosis. Serum titers for known infectious causes of anemia were negative. Examination of the zebra holding areas revealed two hybrid red maple (Acer sp.) trees. There was no known exposure to other hemolytic agents. This is the first report of probable red maple-induced hemolysis in zebra.

  5. High Pressure Inactivation of HAV within Mussels

    Science.gov (United States)

    The potential of hepatitis A virus (HAV) to be inactivated within Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) by high pressure processing was evaluated. HAV was bioaccumulated within mussels to approximately 6-log10 PFU by exposure of mussels to HAV-contamina...

  6. Superhydrophilic Thin-Film Composite Forward Osmosis Membranes for Organic Fouling Control: Fouling Behavior and Antifouling Mechanisms

    KAUST Repository

    Tiraferri, Alberto

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes. © 2012 American Chemical Society.

  7. Superhydrophilic thin-film composite forward osmosis membranes for organic fouling control: fouling behavior and antifouling mechanisms.

    Science.gov (United States)

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes.

  8. Milk fouling in heat exchangers

    NARCIS (Netherlands)

    Jeurnink, T.J.M.

    1996-01-01


    The mechanisms of fouling of heat exchangers by milk were studied. Two major fouling mechanisms were indentified during the heat treatment of milk: (i) the formation and the subsequent deposition of activated serum protein molecules as a result of the heat denaturation; (ii) the

  9. Early detection monitoring for larval dreissenid mussels: how much plankton sampling is enough?

    Science.gov (United States)

    Counihan, Timothy D; Bollens, Stephen M

    2017-03-01

    The development of quagga and zebra mussel (dreissenids) monitoring programs in the Pacific Northwest provides a unique opportunity to evaluate a regional invasive species detection effort early in its development. Recent studies suggest that the ecological and economic costs of a dreissenid infestation in the Pacific Northwest of the USA would be significant. Consequently, efforts are underway to monitor for the presence of dreissenids. However, assessments of whether these efforts provide for early detection are lacking. We use information collected from 2012 to 2014 to characterize the development of larval dreissenid monitoring programs in the states of Idaho, Montana, Oregon, and Washington in the context of introduction and establishment risk. We also estimate the effort needed for high-probability detection of rare planktonic taxa in four Columbia and Snake River reservoirs and assess whether the current level of effort provides for early detection. We found that the effort expended to monitor for dreissenid mussels increased substantially from 2012 to 2014, that efforts were distributed across risk categories ranging from high to very low, and that substantial gaps in our knowledge of both introduction and establishment risk exist. The estimated volume of filtered water required to fully census planktonic taxa or to provide high-probability detection of rare taxa was high for the four reservoirs examined. We conclude that the current level of effort expended does not provide for high-probability detection of larval dreissenids or other planktonic taxa when they are rare in these reservoirs. We discuss options to improve early detection capabilities.

  10. The use of positive reinforcement in training zebra sharks (Stegostoma fasciatum).

    Science.gov (United States)

    Marranzino, Ashley

    2013-01-01

    Positive reinforcement training (PRT) was used on 4 adult zebra sharks, Stegostoma fasciatum, housed at the Downtown Aquarium, Denver, to determine the ability of zebra sharks to become desensitized to various stimuli associated with veterinary procedures. One male and 3 female sharks were trained for 12 weeks. As a result of PRT, all 4 zebra sharks were desensitized to staying within a closed holding tank off of the main exhibit, the presence of multiple trainers in the closed holding tank, and tactile stimulation. One of the 4 zebra sharks was also successfully desensitized to the presence of a stretcher being brought into the holding tank. All of these procedures are common in veterinary examinations, and it is hoped that desensitization to these stimuli will reduce the stress associated with examinations. The training accomplished has allowed for easier maintenance of the zebra sharks by the aquarium staff and an improvement in the care of the sharks.

  11. Characterization of fouling of membrane contactors

    DEFF Research Database (Denmark)

    Ciurkot, Kaludia; Zarebska, Agata; Christensen, Knud Villy

    2013-01-01

    of ammonia and membrane fouling tendency. The surface morphology of both clean and fouled membranes by model manure solution and undigested pig manure has been studied by: Optical and Atomic Force Microscopy and contact angle measurements. Based on the experimental results, it is concluded that real manure...... achieved higher ammonia removal than the synthetic model manure solution. This might be due to the larger particle size of the milled straw in the model solution compared to the size of suspended solids present in real manure. From the fouling autopsy, it was found that PTFE membranes are more prone...... to fouling than PP membranes. In both membranes the hydrophobicity decreased after running the process for 30 h, especially when undigested pig manure was used....

  12. Interpretation of experiments made in ZEBRA CADENZA assemblies with CEA formulary

    International Nuclear Information System (INIS)

    D'Angelo, A.; Rimpault, G.

    1983-06-01

    A benchmark exercise on fast critical heterogeneity method assessment has been proposed in the framework of NEACRP. It is based on the analysis of two integral experiments performed by UKAEA on the ZEBRA facility (the CADENZA assemblies): - a plate fuelled core (ZEBRA 22); - a 75% pin fuelled core (ZEBRA 23). The interpretation of these experiments has been done using the current standard CEA methods. We find a relevant (650 pcm) discrepancy between the ''k'' values of ZEBRA 22 and ZEBRA 23 pin assemblies. We try in this report to find out the origin of this discrepancy. The spatial k-value calculation results and corrections are affected by nomore than 150 pcm and are partially correlated. Moreover, this discrepancy does not seem to be explained in terms of homogenous infinite dilute cross section effects. It has been found that most of the discrepancy can be traced back to heterogeneity effects, and mainly to the heterogeneity effects of the metallic fuel plate in the metallic fuel plate in the ZEBRA 22 cell. Finally, the pin core gives, in the CEA analysis, a Keff E-C value well inside the known performance of the adjusted CARNAVAL IV formulaire (i.e. E-C =+ 300 + +500+-200 pcm) for plutonium fuelled cores

  13. Reliability Based Management of Marine Fouling

    DEFF Research Database (Denmark)

    Faber, Michael Havbro; Hansen, Peter Friis

    1999-01-01

    The present paper describes the results of a recent study on the application of methods from structural reliability to optimise management of marine fouling on jacket type structures.In particular the study addresses effects on the structural response by assessment and quantification of uncertain......The present paper describes the results of a recent study on the application of methods from structural reliability to optimise management of marine fouling on jacket type structures.In particular the study addresses effects on the structural response by assessment and quantification...... of uncertainties of a set of parameters. These are the seasonal variation of marine fouling parameters, the wave loading (taking into account the seasonal variation in sea-state statistics), and the effects of spatial variations and seasonal effects of marine fouling parameters. Comparison of design values...

  14. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: Isolation, characterization, and fouling effect of EfOM fractions

    KAUST Repository

    Zheng, Xing

    2014-11-01

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids, hydrophobic acids (HPO-A), transphilic neutrals and acids (TPI), and hydrophilics (HPI), and tested their fouling effect in both salt solution and pure water during ultrafiltration (UF). Major functional groups and chemical structure of the isolates were identified using Fourier transform infrared spectroscopy (FT-IR) and solid-state carbon nuclear magnetic resonance (13C NMR) analysis. The influence of the isolation process on the properties of EfOM fractions was minor because the raw and reconstituted secondary effluents were found similar with respect to UV absorbance, molecular size distribution, and fluorescence character. In membrane filtration tests, unified membrane fouling index (UMFI) and hydraulic resistance were used to quantify irreversible fouling potential of different water samples. Results show that under similar DOC level in feed water, colloids present much more irreversible fouling than other fractions. The fouling effect of the isolates is related to their size, chemical properties, and solution chemistry. Further investigations have identified that the interaction between colloids and other fractions also influences the performance of colloids in fouling phenomena. © 2014 Elsevier Ltd.

  15. Female Zebra Finches Smell Their Eggs.

    Directory of Open Access Journals (Sweden)

    Sarah Golüke

    Full Text Available Parental investment in unrelated offspring seems maladaptive from an evolutionary perspective, due to the costs of energy and resources that cannot be invested in related offspring at the same time. Therefore selection should favour mechanisms to discriminate between own and foreign offspring. In birds, much emphasis has been placed on understanding the visual mechanisms underlying egg recognition. However, olfactory egg recognition has almost been completely ignored. Here, we investigated whether female zebra finches (Taeniopygia guttata are able to discriminate between their own and a conspecific egg based on olfactory cues alone. Zebra finches are colonial-breeding songbirds. Eggs are monomorphic, i.e. without any spotting pattern, and intraspecific brood parasitism frequently occurs. In a binary choice experiment, female zebra finches were given the choice between the scent of their own and a conspecific egg. After the onset of incubation, females chose randomly and showed no sign of discrimination. However, shortly before hatching, females preferred significantly the odour of their own egg. The finding that females are capable to smell their own egg may inspire more research on the potential of olfaction involved in egg recognition, especially in cases where visual cues might be limited.

  16. Fouling mechanisms of dairy streams during membrane distillation

    NARCIS (Netherlands)

    Hausmann, A.; Sanciolo, P.; Vasiljevic, T.; Weeks, M.; Schroën, C.G.P.H.; Gray, S.; Duke, M.

    2013-01-01

    This study reports on fouling mechanisms of skim milk and whey during membrane distillation (MD) using polytetrafluoroethylene (PTFE) membranes. Structural and elemental changes along the fouling layer from the anchorpoint at the membrane to the topsurface of the fouling layer have been investigated

  17. KARAKTERISTIK INTERAKSI MEMBRAN-FOULANT DAN FOULANT-FOULANT SEBAGAI DASAR PENGENDALIAN FOULING

    Directory of Open Access Journals (Sweden)

    Heru Susanto

    2012-05-01

    Full Text Available THE CHARACTERISTICS OF MEMBRANE-FOULANT AND FOULANT-FOULANT INTERACTIONS AS THE BASIS FOR CONTROL OF FOULING. Industrial membrane applications for solid liquid and liquid-liquid filtration are limited by fouling and concentration polarization. Because fouling significantly reduces the membrane performance and often changes the membrane selectivity, efforts to overcome the fouling problem are very important from practical applications point of view. This paper presents the basic knowledge required to control fouling and recent development in fouling control including the method developed by the author. Control of fouling can be done by (i commercial membrane modification (post modification by photo-graft polymerization, (ii modification by polymer blending during membrane manufacturing and (iii integration of a pretreatment into membrane processes. The results showed that all the developed methods can significantly reduce the resulting fouling; however, none of the method could totally remove the occurring fouling. The understanding of the membrane-foulant and foulant-foulant interactions is the key to success in control of fouling.Aplikasi teknologi membran untuk pemisahan padat cair di  berbagai industri dibatasi oleh peristiwa fouling yang menyebabkan penurunan laju produk dan perubahan selektifitas membran. Oleh karena itu, pengendalian fouling merupakan upaya yang mutlak harus dilakukan. Makalah ini mempresentasikan pengetahuan dasar yang diperlukan untuk pengendalian fouling dan perkembangan terkini dalam pengendalian fouling termasuk hasil-hasil yang telah dikembangkan oleh penulis. Pengendalian fouling dilakukan dengan (i modifikasi membran komersial (post modification menggunakan metode photo-grafting, (ii modifikasi dengan pencampuran polimer selama proses pembuatan (polymer blend dan (iii integrasi unit perlakuan awal (pre-treatment dengan proses membran. Hasil penelitian menunjukkan bahwa kesemua metode yang dikembangkan dapat

  18. Fouling distribution in forward osmosis membrane process.

    Science.gov (United States)

    Lee, Junseok; Kim, Bongchul; Hong, Seungkwan

    2014-06-01

    Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis (FO) membrane process. The flux distribution model developed in this study showed a good agreement with experimental results, validating the robustness of the model. This model demonstrated, as expected, that the permeate flux decreased along the membrane channel due to decreasing osmotic pressure differential across the FO membrane. A series of fouling experiments were conducted under the draw and feed solutions at various recoveries simulated by the model. The simulated fouling experiments revealed that higher organic (alginate) fouling and thus more flux decline were observed at the last section of a membrane channel, as foulants in feed solution became more concentrated. Furthermore, the water flux in FO process declined more severely as the recovery increased due to more foulants transported to membrane surface with elevated solute concentrations at higher recovery, which created favorable solution environments for organic adsorption. The fouling reversibility also decreased at the last section of the membrane channel, suggesting that fouling distribution on FO membrane along the module should be carefully examined to improve overall cleaning efficiency. Lastly, it was found that such fouling distribution observed with co-current flow operation became less pronounced in counter-current flow operation of FO membrane process. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  19. Mussel-inspired chemistry and its application

    NARCIS (Netherlands)

    Yang, J.

    2016-01-01

    Mussels can affix themselves to a variety of wet surfaces under harsh marine conditions by secreting liquid mussel foot proteins (mfps) as superglues. Inside the mussel, the superglues are fluid-like and are kept at low pH, i.e. pH 3. Upon secretion into seawater at pH 8, the superglues are cured

  20. Molecular Mechanisms of Ultrafiltration Membrane Fouling in Polymer-Flooding Wastewater Treatment: Role of Ions in Polymeric Fouling.

    Science.gov (United States)

    Liu, Guicai; Yu, Shuili; Yang, Haijun; Hu, Jun; Zhang, Yi; He, Bo; Li, Lei; Liu, Zhiyuan

    2016-02-02

    Polymer (i.e., anionic polyacrylamide (APAM)) fouling of polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes and its relationships to intermolecular interactions were investigated using atomic force microscopy (AFM). Distinct relations were obtained between the AFM force spectroscopy measurements and calculated fouling resistance over the concentration polarization layer (CPL) and gel layer (GL). The measured maximum adhesion forces (Fad,max) were closely correlated with the CPL resistance (Rp), and the proposed molecular packing property (largely based on the shape of AFM force spectroscopy curve) of the APAM chains was related to the GL resistance (Rg). Calcium ions (Ca(2+)) and sodium ions (Na(+)) caused more severe fouling. In the presence of Ca(2+), the large Rp corresponded to high foulant-foulant Fad,max, resulting in high flux loss. In addition, the Rg with Ca(2+) was minor, but the flux recovery rate after chemical cleaning was the lowest, indicating that Ca(2+) created more challenges in GL cleaning. With Na(+), the fouling behavior was complicated and concentration-dependent. The GL structures with Na(+), which might correspond to the proposed molecular packing states among APAM chains, played essential roles in membrane fouling and GL cleaning.

  1. On-line fouling monitor for heat exchangers

    International Nuclear Information System (INIS)

    Tsou, J.L.

    1995-01-01

    Biological and/or chemical fouling in utility service water system heat exchangers adversely affects operation and maintenance costs, and reduced heat transfer capability can force a power deaerating or even a plant shut down. In addition, service water heat exchanger performance is a safety issue for nuclear power plants, and the issue was highlighted by NRC in Generic Letter 89-13. Heat transfer losses due to fouling are difficult to measure and, usually, quantitative assessment of the impact of fouling is impossible. Plant operators typically measure inlet and outlet water temperatures and flow rates and then perform complex calculations for heat exchanger fouling resistance or ''cleanliness''. These direct estimates are often imprecise due to inadequate instrumentation. Electric Power Research Institute developed and patented an on-line condenser fouling monitor. This monitor may be installed in any location within the condenser; does not interfere with routine plant operations, including on-line mechanical and chemical treatment methods; and provides continuous, real-time readings of the heat transfer efficiency of the instrumented tube. This instrument can be modified to perform on-line monitoring of service water heat exchangers. This paper discusses the design, construction of the new monitor, and algorithm used to calculate service water heat exchanger fouling

  2. Optimal design of tests for heat exchanger fouling identification

    International Nuclear Information System (INIS)

    Palmer, Kyle A.; Hale, William T.; Such, Kyle D.; Shea, Brian R.; Bollas, George M.

    2016-01-01

    Highlights: • Built-in test design that optimizes the information extractable from the said test. • Method minimizes the covariance of a fault with system uncertainty. • Method applied for the identification and quantification of heat exchanger fouling. • Heat exchanger fouling is identifiable despite the uncertainty in inputs and states. - Graphical Abstract: - Abstract: Particulate fouling in plate fin heat exchangers of aircraft environmental control systems is a recurring issue in environments rich in foreign object debris. Heat exchanger fouling detection, in terms of quantification of its severity, is critical for aircraft maintenance scheduling and safe operation. In this work, we focus on methods for offline fouling detection during aircraft ground handling, where the allowable variability range of admissible inputs is wider. We explore methods of optimal experimental design to estimate heat exchanger inputs and input trajectories that maximize the identifiability of fouling. In particular, we present a methodology in which D-optimality is used as a criterion for statistically significant inference of heat exchanger fouling in uncertain environments. The optimal tests are designed on the basis of a heat exchanger model of the inherent mass, energy and momentum balances, validated against literature data. The model is then used to infer sensitivities of the heat exchanger outputs with respect to fouling metrics and maximize them by manipulating input trajectories; thus enhancing the accuracy in quantifying the fouling extent. The proposed methodology is evaluated with statistical indices of the confidence in estimating thermal fouling resistance at uncertain operating conditions, explored in a series of case studies.

  3. Fouling in organic-cooled systems

    International Nuclear Information System (INIS)

    Charlesworth, D.H.

    1963-04-01

    Studies of organic coolants in the out-reactor 250-0-1 loop and in the in-reactor X-7 loop have shown that fouling films are deposited on heat-transfer surfaces by two mechanisms, one involving soluble impurities and the other insoluble impurities in the coolant. The simultaneous action of two mechanisms of deposition can lead to a wide variety of compositions and structures of the deposited film. The concentration of impurities is the most important factor controlling the deposition rate. Coolant velocity and surface temperature also have major effects on the fouling rate. At low chlorine levels continuous coolant cleanup through Attapulgus clay has been shown to reduce deposition rates under representative reactor conditions from 100 μg/cm 2 hr to 1 μg/cm 2 hr. Chlorine, which is a strong promoter of fouling, is not removed by Attapulgus clay. Further studies of its important effect on fouling and its removal will be the subjects of separate reports. An acceptable deposition rate of 0.3 μg/cm 2 hr should be achieved by intensive purification, coupled with the exclusion of impurities such as chlorine. (author)

  4. Systemic equid alphaherpesvirus 9 in a Grant's zebra.

    Science.gov (United States)

    Moeller, Robert B; Crossley, Beate; Pipkin, Arlena; Li, Yanqiu; Balasuriya, Udeni B R

    2018-04-01

    A 2-y-old female Grant's zebra ( Equus quagga [ burchellii] boehmi) was presented with a clinical history of depression, anorexia, and weakness of 1-wk duration. Postmortem examination identified ulcers on the tongue and palate; a large abscess adjacent to the larynx; left lung consolidation; mild swelling, darkening, and congestion of the liver with accentuation of the lobular pattern; and edema and congestion of the distal small and large intestines. Histologic examination identified necrotizing bronchopneumonia, necrotizing hepatitis, nephritis, and enterocolitis. Eosinophilic intranuclear inclusions were detected in syncytial cells and degenerate bronchial epithelium in the lungs and in some hepatocytes associated with necrotic foci. Bacterial cultures of the lung, liver, and laryngeal abscess failed to detect any significant pathogen. Lung and liver tested positive for equine herpesvirus with neuropathogenic marker by real-time PCR. Subsequently, equine herpesvirus was isolated in tissue culture, and the entire viral DNA polymerase gene (ORF30) was sequenced. The zebra lung isolate had a very close nucleotide and amino acid sequence identity to equid alphaherpesvirus 9 (EHV-9; 99.6% and 99.8%, respectively) in contrast to the neuropathogenic T953 strain of EHV-1 (94.7% and 96.6%, respectively). Although zebras are considered the natural host for EHV-9, we document an unusual acute systemic, fatal EHV-9 infection in a 2-y-old Grant's zebra.

  5. High Concentration Protein Ultrafiltration: a Comparative Fouling Assessment

    Science.gov (United States)

    Lim, Y. P.; Mohammad, A. W.

    2018-05-01

    In this paper, the predominant fouling mechanism via pH manipulation in gelatin ultrafiltration (UF) at constant operating pressure was studied. Two 30 kDa molecular weight cut off (MWCO) UF membranes with different hydrophilic/hydrophobic properties were tested at solution pH near gelatin isoelectric point (IEP), pH below and above gelatin’s IEP. The resistance-in-series model was used to determine quantitatively the contribution of each filtration resistance occurred during gelatin UF. The governing fouling mechanisms were investigated using classical blocking laws. The results demonstrated that concentration polarization remain as dominant fouling resistance in gelatin UF, but exceptional case was observed at pH away from gelatin’s IEP, showing that combined reversible and irreversible fouling resistances contributed around 57% and 37%, respectively to the overall fouling resistances. Under all experimental condition tested, permeate flux decline was accurately predicted by all the models studied. Fouling profile was fitted well with “Standard Blocking”, “Intermediate Blocking” and “Cake Filtration” model for regenerated cellulose acetate (RCA) membrane and “Cake Filtration” model for polyethersulphone (PES) membrane.

  6. Short Review on Predicting Fouling in RO Desalination

    Directory of Open Access Journals (Sweden)

    Alejandro Ruiz-García

    2017-10-01

    Full Text Available Reverse Osmosis (RO membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered.

  7. Comparative study of predatory responses in blue mussels (Mytilus edulis L.) produced in suspended long line cultures or collected from natural bottom mussel beds

    DEFF Research Database (Denmark)

    Christensen, Helle Torp; Dolmer, Per; Petersen, Jens Kjerulf

    2011-01-01

    Blue mussels (Mytilus edulis L.) are a valuable resource for commercial shellfish production and may also have uses as a tool in habitat improvement, because mussel beds can increase habitat diversity and complexity. A prerequisite for both commercial mussel production and habitat improvement...... originated from suspended cultures had a higher length increment and lower mortality when compared to bottom mussels. It is concluded that suspended mussels potentially are an alternative resource to bottom culture and can be used in habitat improvement of mussel beds, but that the use of suspended mussels...

  8. Asphaltene Aggregation and Fouling Behavior

    Science.gov (United States)

    Derakhshesh, Marzie

    This thesis explored the properties of asphaltene nano-aggregates in crude oil and toluene based solutions and fouling at process furnace temperatures, and the links between these two phenomena. The link between stability of asphaltenes at ambient conditions and fouling at the conditions of a delayed coker furnace, at over 450 °C, was examined by blending crude oil with an aliphatic diluent in different ratios. The stability of the blends were measured using a S-value analyzer, then fouling rates were measured on electrically heated stainless steel 316 wires in an autoclave reactor. The less stable the blend, the greater the rate and extent of fouling. The most severe fouling occurred with the unstable asphaltenes. SEM imaging of the foulant illustrates very different textures, with the structure becoming more porous with lower stability. Under cross-polarized light, the coke shows the presence of mesophase in the foulant layer. These data suggest a correlation between the fouling rate at high temperature furnace conditions and the stability index of the crude oil. Three organic polysulfides were introduced to the crude oil to examine their effect on fouling. The polysulfides are able to reduce coking and carbon monoxide generation in steam crackers. The fouling results demonstrated that polysulfide with more sulfur content increased the amount of corrosion-fouling of the wire. Various additives, solvents, ultrasound, and heat were employed to attempt to completely disaggregate the asphaltene nano-aggregates in solution at room temperature. The primary analytical technique used to monitor the nano-aggregation state of the asphaltenes in solution was the UV-visible spectroscopy. The results indicate that stronger solvents, such as pyridine and quinoline, combined with ionic liquids yield a slight reduction in the apparent absorbance at longer wavelengths, indicative of a decrease in the nano-aggregate size although the magnitude of the decrease is not significant

  9. CROSS-FLOW ULTRAFILTRATION OF SECONDARY EFFLUENTS. MEMBRANE FOULING ANALYSIS

    Directory of Open Access Journals (Sweden)

    Luisa Vera

    2014-12-01

    Full Text Available The application of cross-flow ultrafiltration to regenerate secondary effluents is limited by membrane fouling. This work analyzes the influence of the main operational parameters (transmembrane pressure and cross-flow velocity about the selectivity and fouling observed in an ultrafiltration tubular ceramic membrane. The experimental results have shown a significant retention of the microcolloidal and soluble organic matter (52 – 54% in the membrane. The fouling analysis has defined the critical operational conditions where the fouling resistance is minimized. Such conditions can be described in terms of a dimensionless number known as shear stress number and its relationship with other dimensionless parameter, the fouling number.

  10. A survey of gas-side fouling in industrial heat-transfer equipment

    Science.gov (United States)

    Marner, W. J.; Suitor, J. W.

    1983-11-01

    Gas-side fouling and corrosion problems occur in all of the energy intensive industries including the chemical, petroleum, primary metals, pulp and paper, glass, cement, foodstuffs, and textile industries. Topics of major interest include: (1) heat exchanger design procedures for gas-side fouling service; (2) gas-side fouling factors which are presently available; (3) startup and shutdown procedures used to minimize the effects of gas-side fouling; (4) gas-side fouling prevention, mitigation, and accommodation techniques; (5) economic impact of gas-side fouling on capital costs, maintenance costs, loss of production, and energy losses; and (6) miscellaneous considerations related to gas-side fouling. The present state-of-the-art for industrial gas-side fouling is summarized by a list of recommendations for further work in this area.

  11. A comprehensive review of milk fouling on heated surfaces.

    Science.gov (United States)

    Sadeghinezhad, E; Kazi, S N; Dahari, M; Safaei, Mohammad Reza; Sadri, Rad; Badarudin, A

    2015-01-01

    Heat exchanger performance degrades rapidly during operation due to formation of deposits on heat transfer surfaces which ultimately reduces service life of the equipment. Due to scaling, product deteriorates which causes lack of proper heating. Chemistry of milk scaling is qualitatively understood and the mathematical models for fouling at low temperatures have been produced but the behavior of systems at ultra high temperature processing has to be studied further to understand in depth. In diversified field, the effect of whey protein fouling along with pressure drop in heat exchangers were conducted by many researchers. Adding additives, treatment of heat exchanger surfaces and changing of heat exchanger configurations are notable areas of investigation in milk fouling. The present review highlighted information about previous work on fouling, influencing parameters of fouling and its mitigation approach and ends up with recommendations for retardation of milk fouling and necessary measures to perform the task.

  12. Freshwater mussel response to bedform movement: experimental stream studies

    Science.gov (United States)

    Kozarek, J. L.; MacGregor, K. R.; Hornbach, D.; Hove, M.

    2017-12-01

    Freshwater mussels are intrinsically linked to near-bed sediment dynamics, but it remains unclear how mussels respond to changing sediment loads across spatial and temporal scales. The interactions between mussels and sediment transport are complex and often involve feedback loops. Mussels are filter feeders removing suspended particles from the water column and the physical presence of mussels can have significant impacts on the structure of riverbed habitat. We investigated the feedbacks between mussels, flow, and migrating bedforms during flood experiments in the St. Anthony Falls Laboratory Outdoor StreamLab (OSL) at the University of Minnesota. The OSL is a field-scale sand-bed meandering stream channel with independent control over sediment feed (recirculated) and water flow (diverted from the Mississippi River). Mussel location, orientation to flow, and protrusion from sediment was surveyed immediately before, after, and one and two days after each flood event. Flow fields, bed shear stress, bedform migration, and bar topography were measured during each flooding event with and without mussels present (density = 4/m2 and 8/m2) to quantify the influence of mussels on channel morphology and bedform migration. Mobile bedforms (up to 14 cm high) were present for all flood events with quasi-equilibrium, aggrading, and degrading bed conditions. Mussels moved little horizontally during all flood events, but were shown to move quickly to deeper water after the flood receded. However, mussels moved vertically, burrowing or being buried under mobile bedforms, during each flood event. The research presented here will focus on feedbacks between three mussel species with different shell sculptures, flow conditions, and migrating bedforms during flooding events. These results reveal how freshwater mussels respond to and affect flow and sediment transport during flood events that are difficult to observe in the field.

  13. Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, Carles, E-mail: carles.ibanez@irta.cat [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alcaraz, Carles; Caiola, Nuno; Rovira, Albert; Trobajo, Rosa [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alonso, Miguel [United Research Services S.L., Urgell 143, 08036 Barcelona, Catalonia (Spain); Duran, Concha [Confederacion Hidrografica del Ebro, Sagasta 24-26, 50071 Zaragoza, Aragon (Spain); Jimenez, Pere J. [Grup Natura Freixe, Major 56, 43750 Flix, Catalonia (Spain); Munne, Antoni [Agencia Catalana de l' Aigua, Provenca 204-208, 08036 Barcelona, Catalonia (Spain); Prat, Narcis [Departament d' Ecologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona Catalonia (Spain)

    2012-02-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. - Highlights: Black-Right-Pointing-Pointer We show a regime shift in a large river from phytoplankton to macrophyte dominance. Black-Right-Pointing-Pointer Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. Black-Right-Pointing-Pointer Phosphorus depletion is found to be the main cause of the phytoplankton decline. Black-Right-Pointing-Pointer We conclude that oligotrophication triggered the colonization of macrophytes. Black-Right-Pointing-Pointer This new regime shift in a river is similar to that described

  14. Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects

    International Nuclear Information System (INIS)

    Ibáñez, Carles; Alcaraz, Carles; Caiola, Nuno; Rovira, Albert; Trobajo, Rosa; Alonso, Miguel; Duran, Concha; Jiménez, Pere J.; Munné, Antoni; Prat, Narcís

    2012-01-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. - Highlights: ► We show a regime shift in a large river from phytoplankton to macrophyte dominance. ► Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. ► Phosphorus depletion is found to be the main cause of the phytoplankton decline. ► We conclude that oligotrophication triggered the colonization of macrophytes. ► This new regime shift in a river is similar to that described in shallow lakes.

  15. A southern African origin and cryptic structure in the highly mobile plains zebra.

    Science.gov (United States)

    Pedersen, Casper-Emil T; Albrechtsen, Anders; Etter, Paul D; Johnson, Eric A; Orlando, Ludovic; Chikhi, Lounes; Siegismund, Hans R; Heller, Rasmus

    2018-03-01

    The plains zebra (Equus quagga) is an ecologically important species of the African savannah. It is also one of the most numerous and widely distributed ungulates, and six subspecies have been described based on morphological variation. However, the within-species evolutionary processes have been difficult to resolve due to its high mobility and a lack of consensus regarding the population structure. We obtained genome-wide DNA polymorphism data from more than 167,000 loci for 59 plains zebras from across the species range, encompassing all recognized extant subspecies, as well as three mountain zebras (Equus zebra) and three Grevy's zebras (Equus grevyi). Surprisingly, the population genetic structure does not mirror the morphology-based subspecies delineation, underlining the dangers of basing management units exclusively on morphological variation. We use demographic modelling to provide insights into the past phylogeography of the species. The results identify a southern African location as the most likely source region from which all extant populations expanded around 370,000 years ago. We show evidence for inclusion of the extinct and phenotypically divergent quagga (Equus quagga quagga) in the plains zebra variation and reveal that it was less divergent from the other subspecies than the northernmost (Ugandan) extant population.

  16. Fouling-induced enzyme immobilization for membrane reactors

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Jonsson, Gunnar Eigil

    2013-01-01

    A simple enzyme immobilization method accomplished by promoting membrane fouling formation is proposed. The immobilization method is based on adsorption and entrapment of the enzymes in/on the membrane. To evaluate the concept, two membrane orientations, skin layer facing feed (normal mode......, but the reverse mode allowed for higher enzyme loading and stability, and irreversible fouling (i.e. pore blocking) developed more readily in the support structure than in the skin layer. Compared with an enzymatic membrane reactor (EMR) with free enzymes, the novel EMR with enzymes immobilized in membrane......) and support layer facing feed (reverse mode), were used to immobilize alcohol dehydrogenase (ADH, EC 1.1.1.1) and glutamate dehydrogenase (GDH, EC 1.4.1.3), respectively. The nature of the fouling in each mode was determined by filtration fouling models. The permeate flux was larger in the normal mode...

  17. In-line quantification and characterization of membrane fouling

    KAUST Repository

    Bucs, Szilard

    2016-06-16

    Methods of detecting, quantifying and/or characterizing the fouling of a device from a combination of pressure and spectroscopic data are provided. The device can be any device containing components susceptible to fouling. Components can include membranes, pipes, or reactors. Suitable devices include membrane devices, heat exchangers, and chemical or bio-reactors. Membrane devices can include, for example, microfiltration devices, ultrafiltration devices, nanofiltration devices, reverse osmosis, forward osmosis, osmosis, reverse electrodialysis, electro- deionisation or membrane distillation devices. The methods can be applied to any type of membrane, including tubular, spiral, hollow fiber, flat sheet, and capillary membranes. The spectroscopic characterization can include measuring one or more of the absorption, fluorescence, or raman spectroscopic data of one or more foulants. The methods can allow for the early detection and/or characterization of fouling. The characterization can include determining the specific foulant(s) or type of foulant(s) present. The characterization of fouling can allow for the selection of an appropriate de-fouling method and timing.

  18. Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Mourad Laqbaqbi

    2017-03-01

    Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

  19. Fouling detection in heat exchangers by Takagi-Sugeno observers

    International Nuclear Information System (INIS)

    Delrot, Sabrina

    2012-01-01

    The phenomenon of fouling in heat exchangers is currently an important topic. Indeed, the fouling is a costly issue that increases the energy loss (directly or indirectly through an over-sizing of the equipment), and therefore increases the water consumption. As a side effect, fouling increases CO 2 consumption that leads to environmental consequences. Fouling can be detected either on local scale, using expensive and specific sensors or on global scale. Global estimation of fouling can be done by measuring the variation of the mass of the exchanger, or by estimating the efficiency of the exchanger through the transfer coefficient. These two methods require very restricting conditions: a powered exchanger to measure mass variation and a steady state exchanger to estimate the efficiency. The work introduced in this thesis deals with the development of non-linear observers that detect fouling early enough to start an efficient cleaning process. As a beginning, a finite element model of a counter current tubular exchanger was proposed. Then three approaches, based on non-linear Takagi-Sugeno observers, were suggested to detect early fouling in heat exchangers. First approach consisted in a set of observers that estimated the parameters of fouling effect through an interpolation method. The second approach proposed a polynomial Takagi-Sugeno observer, using the theory of sums of squares. Finally, a observer of Takagi-Sugeno type with unknown inputs was developed. As a conclusion, a comparison between those different methods was done. (author)

  20. Kinetic study of seawater reverse osmosis membrane fouling

    KAUST Repository

    Khan, Muhammad

    2013-10-01

    Reverse osmosis (RO) membrane fouling is not a static state but a dynamic phenomenon. The investigation of fouling kinetics and dynamics of change in the composition of the foulant mass is essential to elucidate the mechanism of fouling and foulant-foulant interactions. The aim of this work was to study at a lab scale the fouling process with an emphasis on the changes in the relative composition of foulant material as a function of operating time. Fouled membrane samples were collected at 8 h, and 1, 2, and 4 weeks on a lab-scale RO unit operated in recirculation mode. Foulant characterization was performed by CLSM, AFM, ATR-FTIR, pyrolysis GC-MS, and ICP-MS techniques. Moreover, measurement of active biomass and analysis of microbial diversity were performed by ATP analysis and DNA extraction, followed by pyro-sequencing, respectively. A progressive increase in the abundance of almost all the foulant species was observed, but their relative proportion changed over the age of the fouling layer. Microbial population in all the membrane samples was dominated by specific groups/species belonging to Proteobacteria and Actinobacteria phyla; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age. © 2013 American Chemical Society.

  1. Impact of sludge flocs on membrane fouling in membrane bioreactors

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Niessen, Wolfgang; Jørgensen, Mads Koustrup

    Membrane bioreactors (MBR) are widely used for wastewater treatment, but membrane fouling reduces membrane performance and thereby increases the cost for membranes and fouling control. Large variation in filtration properties measured as flux decline was observed for the different types of sludges....... Further, the flux could partly be reestablished after the relaxation period depending on the sludge composition. The results underline that sludge properties are important for membrane fouling and that control of floc properties, as determined by the composition of the microbial communities...... and the physico-chemical properties, is an efficient method to reduce membrane fouling in the MBR. High concentration of suspended extracellular substances (EPS) and small particles (up to 10 µm) resulted in pronounced fouling propensity. The membrane fouling resistance was reduced at high concentration...

  2. Fitness consequences of polymorphic inversions in the zebra finch genome.

    Science.gov (United States)

    Knief, Ulrich; Hemmrich-Stanisak, Georg; Wittig, Michael; Franke, Andre; Griffith, Simon C; Kempenaers, Bart; Forstmeier, Wolfgang

    2016-09-29

    Inversion polymorphisms constitute an evolutionary puzzle: they should increase embryo mortality in heterokaryotypic individuals but still they are widespread in some taxa. Some insect species have evolved mechanisms to reduce the cost of embryo mortality but humans have not. In birds, a detailed analysis is missing although intraspecific inversion polymorphisms are regarded as common. In Australian zebra finches (Taeniopygia guttata), two polymorphic inversions are known cytogenetically and we set out to detect these two and potentially additional inversions using genomic tools and study their effects on embryo mortality and other fitness-related and morphological traits. Using whole-genome SNP data, we screened 948 wild zebra finches for polymorphic inversions and describe four large (12-63 Mb) intraspecific inversion polymorphisms with allele frequencies close to 50 %. Using additional data from 5229 birds and 9764 eggs from wild and three captive zebra finch populations, we show that only the largest inversions increase embryo mortality in heterokaryotypic males, with surprisingly small effect sizes. We test for a heterozygote advantage on other fitness components but find no evidence for heterosis for any of the inversions. Yet, we find strong additive effects on several morphological traits. The mechanism that has carried the derived inversion haplotypes to such high allele frequencies remains elusive. It appears that selection has effectively minimized the costs associated with inversions in zebra finches. The highly skewed distribution of recombination events towards the chromosome ends in zebra finches and other estrildid species may function to minimize crossovers in the inverted regions.

  3. First report of endosymbionts in Dreissena polymorpha from the brackish Curonian Lagoon, SE Baltic Sea

    Directory of Open Access Journals (Sweden)

    Romualda Chuševė

    2012-11-01

    Full Text Available We report the first results of a parasitological study ofDreissena polymorpha (zebra mussels from the brackishCuronian Lagoon, SE Baltic Sea. Zebra mussels were collected monthlyfrom May to October 2011 from a site near the mouth of the River Nemunas.Three types of endosymbionts were found in the mantle cavity andvisceral mass of the molluscs during dissections, i.e. thecommensal ciliate Conchophthirus acuminatus and parasitic ciliateOphryoglena sp., and rarely encountered, unidentified nematodes.The abundances of C. cuminatus and Ophryoglena sp.were positively associated with host shell length and watertemperature, but no effect of water salinity was detected.As the endosymbionts are either highly host-specific to zebra mussels(C. acuminatus and Ophryoglena sp. or are probablyfree-living organisms that inadvertently infect the molluscs (nematodes,we conclude that the presence of D. polymorpha in theCuronian Lagoon does not pose any serious parasitologicalrisk to native biota. We emphasize, however, that this conclusionshould be treated with caution as it is based on a study conductedonly at a single location. Our work extends the currentlyscarce records of D. polymorpha parasites and commensals frombrackish waters, and adds to a better understanding of the ecologicalimpact this highly invasive mollusc causes in the areas it has invaded.

  4. Fouling of Seawater Reverse Osmosis (SWRO) Membrane: Chemical and Microbiological Characterization

    KAUST Repository

    Khan, Muhammad T.

    2013-12-01

    In spite of abundant water resources, world is suffering from the scarcity of usable water. Seawater Reverse Osmosis (SWRO) desalination technology using polymeric membranes has been recognized as a key solution to water scarcity problem. However, economic sustainability of this advanced technology is adversely impacted by the membrane fouling problem. Fouling of RO membranes is a highly studied phenomenon. However, literature is found to be lacking a detailed study on kinetic and dynamic aspects of SWRO membrane fouling. The factors that impact the fouling dynamics, i.e., pretreatment and water quality were also not adequately studied at full–scale of operation. Our experimental protocol was designed to systematically explore these fouling aspects with the objective to improve the understanding of SWRO membrane fouling mechanisms. An approach with multiple analytical techniques was developed for fouling characterization. In addition to the fouling layer characterization, feed water quality was also analysed to assess its fouling potential. Study of SWRO membrane fouling dynamics and kinetics revealed variations in relative abundance of chemical and microbial constituents of the fouling layer, over operating time. Aromatic substances, most likely humic–like substances, were observed at relatively high abundance in the initial fouling layer, followed by progressive increase in relative abundances of proteins and polysaccharides. Microbial population grown on all membranes was dominated by specific groups/species belonging to different classes of Proteobacteria phylum; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age and with the position of membrane element in RO vessel. Our results demonstrated that source water quality can significantly impact the RO membrane fouling scenarios. Moreover, the major role of chlorination in the SWRO membrane fouling was highlighted. It was found that intermittent mode of chlorination

  5. Subsistence and recreational mussel ( Perna perna ) collecting in ...

    African Journals Online (AJOL)

    Natal. The former collect 200–2501 of mussels annually from about 110 km of rocky shore and the latter 12–501 from 3 km of rocky shore. Recreational collectors are subject to a daily bag limit of 50 mussels and so select larger mussels than ...

  6. Evolutionary process of deep-sea bathymodiolus mussels.

    Science.gov (United States)

    Miyazaki, Jun-Ichi; de Oliveira Martins, Leonardo; Fujita, Yuko; Matsumoto, Hiroto; Fujiwara, Yoshihiro

    2010-04-27

    Since the discovery of deep-sea chemosynthesis-based communities, much work has been done to clarify their organismal and environmental aspects. However, major topics remain to be resolved, including when and how organisms invade and adapt to deep-sea environments; whether strategies for invasion and adaptation are shared by different taxa or unique to each taxon; how organisms extend their distribution and diversity; and how they become isolated to speciate in continuous waters. Deep-sea mussels are one of the dominant organisms in chemosynthesis-based communities, thus investigations of their origin and evolution contribute to resolving questions about life in those communities. We investigated worldwide phylogenetic relationships of deep-sea Bathymodiolus mussels and their mytilid relatives by analyzing nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4) genes. Phylogenetic analysis of the concatenated sequence data showed that mussels of the subfamily Bathymodiolinae from vents and seeps were divided into four groups, and that mussels of the subfamily Modiolinae from sunken wood and whale carcasses assumed the outgroup position and shallow-water modioline mussels were positioned more distantly to the bathymodioline mussels. We provisionally hypothesized the evolutionary history of Bathymodilolus mussels by estimating evolutionary time under a relaxed molecular clock model. Diversification of bathymodioline mussels was initiated in the early Miocene, and subsequently diversification of the groups occurred in the early to middle Miocene. The phylogenetic relationships support the "Evolutionary stepping stone hypothesis," in which mytilid ancestors exploited sunken wood and whale carcasses in their progressive adaptation to deep-sea environments. This hypothesis is also supported by the evolutionary transition of symbiosis in that nutritional adaptation to the deep sea proceeded from extracellular

  7. Inorganic fouling mitigation by salinity cycling in batch reverse osmosis

    OpenAIRE

    Maswadeh, Laith A.; Warsinger, David Elan Martin; Tow, Emily W.; Connors, Grace B.; Swaminathan, Jaichander; Lienhard, John H

    2018-01-01

    Enhanced fouling resistance has been observed in recent variants of reverse osmosis (RO) desalination which use time-varying batch or semi-batch processes, such as closed-circuit RO (CCRO) and pulse flow RO (PFRO). However, the mechanisms of batch processes' fouling resistance are not well-understood, and models have not been developed for prediction of their fouling performance. Here, a framework for predicting reverse osmosis fouling is developed by comparing the fluid residence time in bat...

  8. An Inverse Almost Ideal Demand System for Mussels in Europe

    DEFF Research Database (Denmark)

    Nguyen, Thong Tien

    2012-01-01

    for farmed mussels from Spain, France, Italy, and the Netherlands are inflexible, while demand for Denmark's wild stock mussels is flexible. Dutch mussels are deemed a luxury food, while preferences for mussels from other countries appear independent of the level of total expenditure (i.e., homothetic...

  9. Experimental study on fouling in the heat exchangers of surface water heat pumps

    International Nuclear Information System (INIS)

    Bai, Xuelian; Luo, Te; Cheng, Kehui; Chai, Feng

    2014-01-01

    Fouling in the heat exchangers plays a key role on the performance of surface water heat pumps. It is also the basement for the system design criteria and operation energy efficiency. In this paper, experimental measurements are performed both in the field and the laboratory with different water qualities, temperatures and velocities. The research will focus on the dynamic growth characteristics of fouling and its main components. By studying the variation rules of fouling resistance, the fouling resistance allowance for certain water condition is recommended. Furthermore, a fouling prediction model in surface water heat pump will be developed and validated based on elaborating with fouling principle under specified water conditions. - Highlights: • Field and laboratory experiments are taken to measure the fouling variation. • Fouling growth process can be divided into four stages. • We recommend fouling resistance allowances for certain conditions. • A fouling prdiction model is developed and validated

  10. Tube micro-fouling, boiling and steam pressure after chemical cleaning

    International Nuclear Information System (INIS)

    Hu, M.H.

    1998-01-01

    This paper presents steam pressure trends after chemical cleaning of steam generator tubes at four plants. The paper also presents tube fouling factor that serves as an objective parameter to assess tubing boiling conditions for understanding the steam pressure trend. Available water chemistry data helps substantiate the concept of tube micro-fouling, its effect on tubing boiling, and its impact on steam pressure. All four plants experienced a first mode of decreasing steam pressure in the post-cleaning operation. After 3 to 4 months of operation, the decreasing trend stopped for three plants and then restored to a pre-cleaning value or better. The fourth plant is soil in decreasing trend after 12 months of operation. Dissolved chemicals, such as silica, titanium can precipitate on tube surface. The precipitate micro-fouling can deactivate or eliminate boiling nucleation sites. Therefore, the first phase of the post-cleaning operation suffered a decrease in steam pressure or an increase in fouling factor. It appears that micro fouling by magnetite deposit can activate or create more bubble nucleation sites. Therefore, the magnetite deposit micro-fouling results in a decrease in fouling factor, and a recovery in steam pressure. Fully understanding the boiling characteristics of the tubing at brand new, fouled and cleaned conditions requires further study of tubing surface conditions. Such study should include boiling heat transfer tests and scanning electronic microscope examination. (author)

  11. Halicephalobus gingivalis (Nematoda) infection in a Grevy's zebra (Equus grevyi).

    Science.gov (United States)

    Isaza, R; Schiller, C A; Stover, J; Smith, P J; Greiner, E C

    2000-03-01

    A 6-yr-old female Grevy's zebra (Equus grevyi) with a disseminated rhabditiform nematode infection is described. Antemortem clinical signs were limited to blindness and abnormal behavior believed to be caused by a recurrent nematode-induced uveitis. Histologic examination of the kidneys, heart, eyes, uterus, and lymph nodes revealed granulomas containing multiple sections of rhabditiform nematodes. Most of the recovered nematodes were larval stages with only a few adult females noted. The adults measured 243-297 microm x 11-16 microm (x = 269 x 14 microm). The distinctive rhabditiform esophagi had corpus:isthmus:bulb proportions of 19:11:5. On the basis of adult morphology, the nematode was identified as Halicephalobus gingivalis. This is the first report of this parasite in a zebra and indicates that this parasitic granulomatous disease should be considered in zebras with neurologic disease.

  12. Analysis of fouling in refuse waste incinerators

    NARCIS (Netherlands)

    Beek, van M.C.; Rindt, C.C.M.; Wijers, J.G.; Steenhoven, van A.A.

    2001-01-01

    Gas-side fouling of waste-heat-recovery boilers, caused mainly by the deposition of particulate matter, reduces the heat transfer in the boiler. The fouling as observed on the tube bundles in the boiler of a Dutch refuse waste incinerator varied from thin and powdery for the economizer to thick and

  13. Spatial organisation and biomass development after relaying of mussel seed

    NARCIS (Netherlands)

    Capelle, J.J.; Wijsman, J.W.M.; Schellekens, T.; van Stralen, M.R.; Herman, P.M.J.; Smaal, A.C.

    2014-01-01

    It is not known whether and by what factors spatial heterogeneity in mussels (Mytilus edulis L.) affects mussel production in human-created mussel beds. In a field experiment, the same number of mussels was relayed on four different areas within plots of the same size, resulting in four treatments

  14. Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength

    KAUST Repository

    Lee, Jieun; Jeong, Sanghyun; Ye, Yun; Chen, Vicki; Vigneswaran, Saravanamuthu; Leiknes, TorOve; Liu, Zongwen

    2016-01-01

    The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 4.7 and 10.4, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling interaction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

  15. Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength

    KAUST Repository

    Lee, Jieun

    2016-11-04

    The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 4.7 and 10.4, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling interaction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

  16. Modeling of crude oil fouling in preheat exchangers of refinery distillation units

    Energy Technology Data Exchange (ETDEWEB)

    Jafari Nasr, Mohammad Reza; Majidi Givi, Mehdi [National Petrochemical Research and Technology Company (NPC-RT), P.O. Box 14385, Tehran (Iran)

    2006-10-15

    The aim of this paper is to propose a new model for crude oil fouling in preheat exchangers of crude distillation units. The experimental results of Australian light crude oil with the tube side surface temperature between 200 and 260{sup o}C and fluid velocity ranged 0.25-0.4m/s were used [Z. Saleh, R. Sheikholeslami, A.P. Watkinson, Heat exchanger fouling by a light australian crude oil, in: Heat Exchanger Fouling and Cleaning Fundamentals and Applications, Santa Fe, 2003]. The amount of activation energy depends on the surface temperature has been calculated. A new model including a term for fouling formation and a term for fouling removal due to chemical and tube wall shear stress was proposed, respectively. The main superiority of the model are independent to Pr number, thermal fouling removal and determination of {beta} based on experimental tests. Finally using the proposed model the fouling rate of Australian light crude oil has been calculated and the threshold curves to identify fouling and no fouling formation zones have been drawn. (author)

  17. ZebraZoom: an automated program for high-throughput behavioral analysis and categorization

    Science.gov (United States)

    Mirat, Olivier; Sternberg, Jenna R.; Severi, Kristen E.; Wyart, Claire

    2013-01-01

    The zebrafish larva stands out as an emergent model organism for translational studies involving gene or drug screening thanks to its size, genetics, and permeability. At the larval stage, locomotion occurs in short episodes punctuated by periods of rest. Although phenotyping behavior is a key component of large-scale screens, it has not yet been automated in this model system. We developed ZebraZoom, a program to automatically track larvae and identify maneuvers for many animals performing discrete movements. Our program detects each episodic movement and extracts large-scale statistics on motor patterns to produce a quantification of the locomotor repertoire. We used ZebraZoom to identify motor defects induced by a glycinergic receptor antagonist. The analysis of the blind mutant atoh7 revealed small locomotor defects associated with the mutation. Using multiclass supervised machine learning, ZebraZoom categorized all episodes of movement for each larva into one of three possible maneuvers: slow forward swim, routine turn, and escape. ZebraZoom reached 91% accuracy for categorization of stereotypical maneuvers that four independent experimenters unanimously identified. For all maneuvers in the data set, ZebraZoom agreed with four experimenters in 73.2–82.5% of cases. We modeled the series of maneuvers performed by larvae as Markov chains and observed that larvae often repeated the same maneuvers within a group. When analyzing subsequent maneuvers performed by different larvae, we found that larva–larva interactions occurred as series of escapes. Overall, ZebraZoom reached the level of precision found in manual analysis but accomplished tasks in a high-throughput format necessary for large screens. PMID:23781175

  18. In-line quantification and characterization of membrane fouling

    KAUST Repository

    Bucs, Szilard; Hekkert, Sacco Te Lintel; Staal, Marc Jaap; Vrouwenvelder, Johannes S.

    2016-01-01

    Methods of detecting, quantifying and/or characterizing the fouling of a device from a combination of pressure and spectroscopic data are provided. The device can be any device containing components susceptible to fouling. Components can include

  19. Fish and mussels: importance of fish for freshwater mussel conservation

    Directory of Open Access Journals (Sweden)

    Ronaldo Sousa

    2015-12-01

    Full Text Available Co-extinctions have received trivial consideration in discussions about the global conservation crisis, even though recent studies have emphasised their importance. This situation is even more pronounced in freshwater ecosystems where this phenomenon is largely unrecognized. In this presentation we explore the role of fish for freshwater mussels’ conservation. Freshwater mussels’ need fish as a host to complete their life cycle and given this premise is expected that changes in the fish community due to species extinctions or additions may have great effects. We reviewed the published information and we found: 1 that most of the studies were published in the last few years; 2 that most of the studies were performed in North America (69%, which is probably due to the high number of endemic threatened species in this continent; 3 that most of the mussel species that are specialists in fish hosting are listed as vulnerable or endangered (55%; 4 most studies were performed in laboratory (83% and 5 that the majority of studies were focused on life cycle or on identifying suitable fish hosts of freshwater mussel species with few studies focusing on threats. Since the interaction between fish and freshwater mussels can be easily disrupted and serious threats to this interaction have arisen (e.g. loss and fragmentation of habitat, changes in river flow, climate change, introduction of invasive species, pollution a more holistic approach is needed to find the best management strategies to conserve these animals. In addition, more field studies are required and more information on African, South American and Asian species is essential. Neglect the possible fundamental role of fish in the decline or extinction of freshwater mussels may impair the success of any measure devoted to their conservation; therefore, this issue cannot be ignored.

  20. Fouling on ion-exchange membranes: Classification, characterization and strategies of prevention and control.

    Science.gov (United States)

    Mikhaylin, Sergey; Bazinet, Laurent

    2016-03-01

    The environmentally friendly ion-exchange membrane (IEM) processes find more and more applications in the modern industries in order to demineralize, concentrate and modify products. Moreover, these processes may be applied for the energy conversion and storage. However, the main drawback of the IEM processes is a formation of fouling, which significantly decreases the process efficiency and increases the process cost. The present review is dedicated to the problematic of IEM fouling phenomena. Firstly, the major types of IEM fouling such as colloidal fouling, organic fouling, scaling and biofouling are discussed along with consideration of the main factors affecting fouling formation and development. Secondly, the review of the possible methods of IEM fouling characterization is provided. This section includes the methods of fouling visualization and characterization as well as methods allowing investigations of characteristics of the fouled IEMs. Eventually, the reader will find the conventional and modern strategies of prevention and control of different fouling types. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Developing Molecular Methods to Identify and Quantify Ballast Water Organisms: A Test Case with Cnidarians

    National Research Council Canada - National Science Library

    Kreiser, Brian R

    2004-01-01

    .... Furthermore, biological invasions mediated by ballast water transport have led to some rather severe economic and ecological consequences as seen in the examples of the zebra mussel and green crab...

  2. Fouling in pressure retarded osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Willy

    2008-07-01

    A salinity power field laboratory was established at Sunndalsoera during the fall of 2002 in order to investigate the fouling potential in PRO in conditions prevailing in a typical sea water and a typically Norwegian surface water. The laboratory contained four identical units for long term testing of small samples of flat sheet membranes. The water flux, the differential pressures across the flow channels as well as the temperature in the membrane cell were logged to a computer. The logging data could be monitored from any remote location with access to the internet. Each unit was equipped with an automatically controlled system for membrane cleaning. Several series of osmotic flux experiments of three to eight months duration were executed while investigating the effect of various routines for membrane treatment, including disinfection, backflushing and chemical cleaning. Further, the potential of NOM fouling and CaCO{sub 3} scaling were investigated in more detail during a large number of laboratory experiments performed under controlled conditions at SINTEF Petroleum Research in Trondheim and Lappeenranta University of Technology in Lappeenranta, Finland. The cellulose acetate membrane used for most of the fouling experiments was characterized in order to determine the intrinsic transport parameters of the membrane. Further, the saturation index at the membrane skin with respect to CaCO{sub 3} was modelled both for real cases with typically Norwegian surface waters as well as for the scaling experiments performed with synthetic waters in the laboratory. Several of the membrane samples which were exposed to fouling conditions during the osmotic experiments were subjected to characterization by scanning electron microscopy (SEM), wave length dispersive spectroscopy (WDS), optical microscopy and fluorescence microscopy in order to identify and quantify the foulants that were deposited on the membranes during the experiments. Further, procedures for the estimation

  3. Laterality of suckling behaviour in three zebra species.

    Science.gov (United States)

    Pluháček, Jan; Olléová, Michaela; Bartošová, Jitka; Pluháčková, Jana; Bartoš, Luděk

    2013-01-01

    Although side preference while suckling is an easily characterised lateralised behaviour, few studies have been conducted. We observed laterality in suckling behaviour in three captive zebra species to test two hypotheses: laterality affected by the foal (motor laterality) and laterality affected by the mother. In total we observed 35 foals of Grevy's, plains, and mountain zebra in two zoos and recorded 5128 successful suckling bouts and 9095 unsuccessful suckling attempts. At the population level the only factor affecting side preference of suckling bouts and attempts was the identity of the individual foal. Ten foals showed individual preferences: seven foals preferred suckling from the left side of the mother, three preferred suckling from the right side of the mother. The individual preferences increased with increasing age of the foal. Only one foal was refused more often from the opposite side than the preferred side used for suckling whereas three other foals were refused from the preferred side. Foals that preferred suckling either from left or right side were refused by the mare more often than foals which showed non-preference. Thus lateral preferences in suckling behaviour of zebra foals seem to be in line with the motor laterality hypotheses.

  4. Membrane Bioreactor (MBR) Technology for Wastewater Treatment and Reclamation: Membrane Fouling.

    Science.gov (United States)

    Iorhemen, Oliver Terna; Hamza, Rania Ahmed; Tay, Joo Hwa

    2016-06-15

    The membrane bioreactor (MBR) has emerged as an efficient compact technology for municipal and industrial wastewater treatment. The major drawback impeding wider application of MBRs is membrane fouling, which significantly reduces membrane performance and lifespan, resulting in a significant increase in maintenance and operating costs. Finding sustainable membrane fouling mitigation strategies in MBRs has been one of the main concerns over the last two decades. This paper provides an overview of membrane fouling and studies conducted to identify mitigating strategies for fouling in MBRs. Classes of foulants, including biofoulants, organic foulants and inorganic foulants, as well as factors influencing membrane fouling are outlined. Recent research attempts on fouling control, including addition of coagulants and adsorbents, combination of aerobic granulation with MBRs, introduction of granular materials with air scouring in the MBR tank, and quorum quenching are presented. The addition of coagulants and adsorbents shows a significant membrane fouling reduction, but further research is needed to establish optimum dosages of the various coagulants/adsorbents. Similarly, the integration of aerobic granulation with MBRs, which targets biofoulants and organic foulants, shows outstanding filtration performance and a significant reduction in fouling rate, as well as excellent nutrients removal. However, further research is needed on the enhancement of long-term granule integrity. Quorum quenching also offers a strong potential for fouling control, but pilot-scale testing is required to explore the feasibility of full-scale application.

  5. Knowledge based system for fouling assessment of power plant boiler

    International Nuclear Information System (INIS)

    Afgan, N.H.; He, X.; Carvalho, M.G.; Azevedo, J.L.T.

    1999-01-01

    The paper presents the design of an expert system for fouling assessment in power plant boilers. It is an on-line expert system based on selected criteria for the fouling assessment. Using criteria for fouling assessment based on 'clean' and 'not-clean' radiation heat flux measurements, the diagnostic variable are defined for the boiler heat transfer surface. The development of the prototype knowledge-based system for fouling assessment in power plants boiler comprise the integrations of the elements including knowledge base, inference procedure and prototype configuration. Demonstration of the prototype knowledge-based system for fouling assessment was performed on the Sines power plant. It is a 300 MW coal fired power plant. 12 fields are used with 3 on each side of boiler

  6. International mussel watch

    International Nuclear Information System (INIS)

    Farrington, J.W.; Tripp, B.W.

    1993-01-01

    Deliberate and inadvertent discharges of chemical contaminants of environmental concern to the world's coastal ocean will continue for the foreseeable future, as human population increases and human habitation intensifies in the coastal zone worldwide. The goal of the International Mussel Watch Project is to provide an assessment of the status and trends of chemical contaminants in the world's coastal waters. These data are critical for protecting both the health of people who consume seafood and the health of coastal ecosystems. The International Mussel Watch Project is a global-scale monitoring program based on the concept of a sentinel organism capable of detecting trends in concentrations of several important marine contaminants. These included chlorinated pesticides, fossil-fuel hydrocarbons, and radionuclides from the nuclear fuel cycle and nuclear weapons testing fallout. Since the 1970's, scientists of several countries have been using common bivalve organisms, such as the blue mussels and oysters, to monitor chemical contaminants in coastal waters. Bivalve mollusks are good monitors for several reasons that include their ability to bioconcentrate the chemical contaminants of interest and their sedentary nature, which makes them representative of a specific place

  7. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Amy, Gary L.; Van Dijk, Johannis C.

    2012-01-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  8. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng

    2012-09-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  9. Changing perspectives on pearly mussels, North America's most imperiled animals

    Science.gov (United States)

    Strayer, David L.; Downing, John A.; Haag, Wendell R.; King, Timothy L.; Layzer, James B.; Newton, Teresa J.; Nichols, S. Jerrine

    2004-01-01

    Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have led to a flurry of research on mussel biology, ecology, and conservation. Recent research on mussel feeding, life history, spatial patterning, and declines has augmented, modified, or overturned long-held ideas about the ecology of these animals. Pearly mussel research has begun to benefit from and contribute to current ideas about suspension feeding, life-history theory, metapopulations, flow refuges, spatial patterning and its effects, and management of endangered species. At the same time, significant gaps in understanding and apparent paradoxes in pearly mussel ecology have been exposed. To conserve remaining mussel populations, scientists and managers must simultaneously and aggressively pursue both rigorous research and conservation actions.

  10. Report on Saginaw Bay Area Environmental Policy, Planning and Management survey. Final report, April 1991-March 1992

    Energy Technology Data Exchange (ETDEWEB)

    He, C.; Zhao, W.; Edens, T.C.

    1992-04-01

    An environmental policy, planning, and management survey was conducted in the Saginaw Bay area in the Fall of 1991. The survey identified unemployment, factory closure and environmental quality degradation as the major economic and environmental problems in the area. Surface water contamination, excessive nutrients and zebra mussel infestation were the most serious problems affecting water quality. Soil erosion, excessive fertilization and pesticide applications were the most important non-point sources of water pollution. Toxic chemicals, phosphorus, suspended solids, heavy metals were the major water pollutants in the area. Pollution cleanup, land use planning, and control of zebra mussels were identified as the top implementation priorities for the area. Recommendations made by the respondents for improving environmental quality are summarized in the report.

  11. Fouling mitigation in membrane distillation processes during ammonia stripping from pig manure

    DEFF Research Database (Denmark)

    Zarebska, Agata; Amor, Angel Cid; Ciurkot, Klaudia

    2015-01-01

    Over time fouling leads to membrane wetting. This is the biggest obstacle to widespread use of membrane distillation (MD) for ammonia removal from animal slurry. Feed pretreatment and cleaning strategies of membrane surfaces are the most common methods to prevent or diminish fouling phenomena....... This study investigates preliminary fouling of polypropylene (PP) and polytetrafluoroethylene (PTFE) membranes. A model manure solution was used as feed. In addition cleaning efficiencies with deionized water, NaOH/citric acid, and Novadan agents were studied. Further microfiltration and ultrafiltration were...... examined as manure pretreatment to diminish fouling. To this end polyvinylidene fluoride membranes (PVDF 0.2 µm and 150 kDa respectively) were used. Organic fouling was shown to be dominant. For the model manure solution the fouling comprised lipids, carbohydrates and proteins. For pig slurry the fouling...

  12. Putative clinical piroplasmosis in a Burchell's zebra (Equus quagga burchelli).

    Science.gov (United States)

    Lampen, F; Bhoora, R; Collins, N E; Penzhorn, B L

    2009-12-01

    A 10-year-old tame zebra gelding was presented after suffering from lethargy, nervousness, reported anaemia and icterus as well as a decreased appetite. These symptoms were seen over some months, with changing severity. The animal was immobilised, treated, and blood specimens were submitted for haematology and biochemistry. This report describes molecular characterisation of Theileria equi recovered from this animal, as well as the clinical findings, treatment and historical relevance of piroplasmosis in zebra in southern Africa.

  13. Selective auditory grouping by zebra finches: testing the iambic-trochaic law.

    Science.gov (United States)

    Spierings, Michelle; Hubert, Jeroen; Ten Cate, Carel

    2017-07-01

    Humans have a strong tendency to spontaneously group visual or auditory stimuli together in larger patterns. One of these perceptual grouping biases is formulated as the iambic/trochaic law, where humans group successive tones alternating in pitch and intensity as trochees (high-low and loud-soft) and alternating in duration as iambs (short-long). The grouping of alternations in pitch and intensity into trochees is a human universal and is also present in one non-human animal species, rats. The perceptual grouping of sounds alternating in duration seems to be affected by native language in humans and has so far not been found among animals. In the current study, we explore to which extent these perceptual biases are present in a songbird, the zebra finch. Zebra finches were trained to discriminate between short strings of pure tones organized as iambs and as trochees. One group received tones that alternated in pitch, a second group heard tones alternating in duration, and for a third group, tones alternated in intensity. Those zebra finches that showed sustained correct discrimination were next tested with longer, ambiguous strings of alternating sounds. The zebra finches in the pitch condition categorized ambiguous strings of alternating tones as trochees, similar to humans. However, most of the zebra finches in the duration and intensity condition did not learn to discriminate between training stimuli organized as iambs and trochees. This study shows that the perceptual bias to group tones alternating in pitch as trochees is not specific to humans and rats, but may be more widespread among animals.

  14. Area-intensive bottom culture production of blue mussels, Mytilus edulis (L.)

    DEFF Research Database (Denmark)

    Christensen, Helle Torp

    column have the potential to become an alternative seed source for mussel production in bottom cultures. When compared to mussels collected from natural benthic mussel beds, suspended mussels had an active predator response by developing a significantly stronger attach-ment to the substrate and having...... a more pronounced aggregation behaviour. Bottom mussels exhibited a passive strategy by developing a thicker shell and larger relative size of the posterior adductor muscle. When comparing the performance of suspended and bottom seed mussels on complex and smooth sub-strate, respectively, originally...

  15. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: Isolation, characterization, and fouling effect of EfOM fractions

    KAUST Repository

    Zheng, Xing; Khan, Muhammad; Croue, Jean-Philippe

    2014-01-01

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids

  16. Evolutionary process of deep-sea bathymodiolus mussels.

    Directory of Open Access Journals (Sweden)

    Jun-Ichi Miyazaki

    Full Text Available BACKGROUND: Since the discovery of deep-sea chemosynthesis-based communities, much work has been done to clarify their organismal and environmental aspects. However, major topics remain to be resolved, including when and how organisms invade and adapt to deep-sea environments; whether strategies for invasion and adaptation are shared by different taxa or unique to each taxon; how organisms extend their distribution and diversity; and how they become isolated to speciate in continuous waters. Deep-sea mussels are one of the dominant organisms in chemosynthesis-based communities, thus investigations of their origin and evolution contribute to resolving questions about life in those communities. METHODOLOGY/PRINCIPAL FINDING: We investigated worldwide phylogenetic relationships of deep-sea Bathymodiolus mussels and their mytilid relatives by analyzing nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI and NADH dehydrogenase subunit 4 (ND4 genes. Phylogenetic analysis of the concatenated sequence data showed that mussels of the subfamily Bathymodiolinae from vents and seeps were divided into four groups, and that mussels of the subfamily Modiolinae from sunken wood and whale carcasses assumed the outgroup position and shallow-water modioline mussels were positioned more distantly to the bathymodioline mussels. We provisionally hypothesized the evolutionary history of Bathymodilolus mussels by estimating evolutionary time under a relaxed molecular clock model. Diversification of bathymodioline mussels was initiated in the early Miocene, and subsequently diversification of the groups occurred in the early to middle Miocene. CONCLUSIONS/SIGNIFICANCE: The phylogenetic relationships support the "Evolutionary stepping stone hypothesis," in which mytilid ancestors exploited sunken wood and whale carcasses in their progressive adaptation to deep-sea environments. This hypothesis is also supported by the evolutionary transition of

  17. Engineering factors influencing Corbicula fouling in nuclear-service water systems

    International Nuclear Information System (INIS)

    Henager, C.H.; Johnson, K.I.; Page, T.L.

    1983-06-01

    Corbicula fouling is a continuing problem in nuclear-service water systems. More knowledge of biological and engineering factors is needed to develop effective detection and control methods. A data base on Corbicula fouling was compiled from nuclear and non-nuclear power stations and industries using raw water. This data base was used in an analysis to identify systems and components which are conducive to fouling by Corbicula. Bounds on several engineering parameters such as velocity and temperature which support Corbicula growth are given. Service water systems found in BWR and PWR reactors are listed and those that show fouling are identified. Possible safety implications of Corbicula fouling are discussed for specific service water systems. Several effective control methods in current use include backflushing with heated water, centrifugal strainers, and continuous chlorination during spawning seasons

  18. New environmentally friendly MSPD solid support based on golden mussel shell: characterization and application for extraction of organic contaminants from mussel tissue.

    Science.gov (United States)

    Rombaldi, Caroline; de Oliveira Arias, Jean Lucas; Hertzog, Gabriel Ianzer; Caldas, Sergiane Souza; Vieira, João P; Primel, Ednei Gilberto

    2015-06-01

    The use of golden mussel shells as a solid support in vortex-assisted matrix solid-phase dispersion (MSPD) was evaluated for the first time for extraction of residues of 11 pesticides and nine pharmaceutical and personal care products from mussel tissue samples. After they had been washed, dried, and milled, the mussel shells were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, infrared spectroscopy, and Brunauer-Emmett-Teller analysis. The MSPD procedure with analysis by liquid chromatography-tandem mass spectrometry allowed the determination of target analytes at trace concentrations (nanograms per gram), with mean recoveries ranging from 61 to 107 % and relative standard deviations lower than 18 %. The optimized method consisted of dispersion of 0.5 g of mussel tissue, 0.5 g of NaSO4, and 0.5 g of golden mussel shell for 5 min, and subsequent extraction with 5 mL of ethyl acetate. The matrix effect was evaluated, and a low effect was found for all compounds. The results showed that mussel shell is an effective material and a less expensive material than materials that have traditionally been used, i.e., it may be used in the MSPD dispersion step during the extraction of pesticides and pharmaceutical and personal care products from golden mussel tissues. Graphical Abstract Vortex-assited matrix solid-phase dispersion for extraction of 11 pesticides and 9 PPCPs care products from mussel tissue samples.

  19. Progress Toward Sustainable Mussel Aquaculture in Mar Piccolo, Italy

    Directory of Open Access Journals (Sweden)

    Carmela Caroppo

    2012-09-01

    Full Text Available Mar Piccolo of Taranto is an estuarine basin heavily exploited for commercial mussel (Mytilus galloprovincialis L. farming. The historical renown of the Taranto mussels has suffered over the last decade following policy decisions to expand the mussel farms and to relocate a portion of the urban sewage to an outfall outside of Mar Piccolo. The resulting decline in mussel quality and the quandary of how to restore stability to Taranto mussel production became the focal issue for our application of the systems approach framework (SAF. We simulated the ecological, economic, and social interactions that affect mussel production. Stakeholders and mussel farmers contributed by participating in meetings during the entire exercise. Our simulation analysis provided them with a means for understanding the effects of policy scenarios on the system. We present three aspects from our initial results that demonstrate the value of the SAF, as: (1 an operational model to monitor and better research the status of the ecosystem, (2 a management tool to evaluate sustainable mussel farming strategies, and (3 an opportunity for improved communication with and engagement of stakeholders, policy, and the public. The application has also raised important questions about how the food chain is controlled, what could be changed to stabilize the ecosystem to a higher level of productivity, and what role the public and policy could play in promoting sustainable development.

  20. Membrane Bioreactor (MBR Technology for Wastewater Treatment and Reclamation: Membrane Fouling

    Directory of Open Access Journals (Sweden)

    Oliver Terna Iorhemen

    2016-06-01

    Full Text Available The membrane bioreactor (MBR has emerged as an efficient compact technology for municipal and industrial wastewater treatment. The major drawback impeding wider application of MBRs is membrane fouling, which significantly reduces membrane performance and lifespan, resulting in a significant increase in maintenance and operating costs. Finding sustainable membrane fouling mitigation strategies in MBRs has been one of the main concerns over the last two decades. This paper provides an overview of membrane fouling and studies conducted to identify mitigating strategies for fouling in MBRs. Classes of foulants, including biofoulants, organic foulants and inorganic foulants, as well as factors influencing membrane fouling are outlined. Recent research attempts on fouling control, including addition of coagulants and adsorbents, combination of aerobic granulation with MBRs, introduction of granular materials with air scouring in the MBR tank, and quorum quenching are presented. The addition of coagulants and adsorbents shows a significant membrane fouling reduction, but further research is needed to establish optimum dosages of the various coagulants/adsorbents. Similarly, the integration of aerobic granulation with MBRs, which targets biofoulants and organic foulants, shows outstanding filtration performance and a significant reduction in fouling rate, as well as excellent nutrients removal. However, further research is needed on the enhancement of long-term granule integrity. Quorum quenching also offers a strong potential for fouling control, but pilot-scale testing is required to explore the feasibility of full-scale application.

  1. Byssus Structure and Protein Composition in the Highly Invasive Fouling Mussel Limnoperna fortunei

    Directory of Open Access Journals (Sweden)

    Shiguo Li

    2018-04-01

    Full Text Available Biofouling mediated by byssus adhesion in invasive bivalves has become a global environmental problem in aquatic ecosystems, resulting in negative ecological and economic consequences. Previous studies suggested that mechanisms responsible for byssus adhesion largely vary among bivalves, but it is poorly understood in freshwater species. Understanding of byssus structure and protein composition is the prerequisite for revealing these mechanisms. Here, we used multiple methods, including scanning electron microscope, liquid chromatography–tandem mass spectrometry, transcriptome sequencing, real-time quantitative PCR, inductively coupled plasma mass spectrometry, to investigate structure, and protein composition of byssus in the highly invasive freshwater mussel Limnoperna fortunei. The results indicated that the structure characteristics of adhesive plaque, proximal and distal threads were conducive to byssus adhesion, contributing to the high biofouling capacity of this species. The 3,4-dihydroxyphenyl-α-alanine (Dopa is a major post-transnationally modification in L. fortunei byssus. We identified 16 representative foot proteins with typical repetitive motifs and conserved domains by integrating transcriptomic and proteomic approaches. In these proteins, Lfbp-1, Lffp-2, and Lfbp-3 were specially located in foot tissue and highly expressed in the rapid byssus formation period, suggesting the involvement of these foot proteins in byssus production and adhesion. Multiple metal irons, including Ca2+, Mg2+, Zn2+, Al3+, and Fe3+, were abundant in both foot tissue and byssal thread. The heavy metals in these irons may be directly accumulated by L. fortunei from surrounding environments. Nevertheless, some metal ions (e.g., Ca2+ corresponded well with amino acid preferences of L. fortunei foot proteins, suggesting functional roles of these metal ions by interacting with foot proteins in byssus adhesion. Overall, this study provides structural and

  2. Zebra finches are sensitive to prosodic features of human speech.

    Science.gov (United States)

    Spierings, Michelle J; ten Cate, Carel

    2014-07-22

    Variation in pitch, amplitude and rhythm adds crucial paralinguistic information to human speech. Such prosodic cues can reveal information about the meaning or emphasis of a sentence or the emotional state of the speaker. To examine the hypothesis that sensitivity to prosodic cues is language independent and not human specific, we tested prosody perception in a controlled experiment with zebra finches. Using a go/no-go procedure, subjects were trained to discriminate between speech syllables arranged in XYXY patterns with prosodic stress on the first syllable and XXYY patterns with prosodic stress on the final syllable. To systematically determine the salience of the various prosodic cues (pitch, duration and amplitude) to the zebra finches, they were subjected to five tests with different combinations of these cues. The zebra finches generalized the prosodic pattern to sequences that consisted of new syllables and used prosodic features over structural ones to discriminate between stimuli. This strong sensitivity to the prosodic pattern was maintained when only a single prosodic cue was available. The change in pitch was treated as more salient than changes in the other prosodic features. These results show that zebra finches are sensitive to the same prosodic cues known to affect human speech perception. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  3. Mussel dredging: Impact on epifauna in Limfjorden, Denmark

    DEFF Research Database (Denmark)

    Dolmer, Per

    2002-01-01

    Species composition and population density of epibenthos are described in two areas in Limfjorden, Denmark. Both areas covered both a mussel fishing ground and an area that has been permanently closed for mussel dredging since 1988. Furthermore, mussels were dredged in a part of the mussel fishing...... grounds in both areas four months before the investigations. The rest of the fishing grounds had not been exploited for at least four years. This study describes the short-term impact (4 mo) and long-term impact (>4 y) of mussel dredging using the permanently closed areas as controls. The data were...... analyzed by multivariate statistics. In both short-term study areas significant effects of dredging were observed. A number of taxa (sponges, echinoderms, anthozoans, molluscs, crustaceans, and ascidians) had a reduced density or were not observed in fished areas four months after the fishing was ended...

  4. Comparative performance of the mussels Perna perna and Perna viridis, cultivated at four different depths

    Directory of Open Access Journals (Sweden)

    Marielyn García

    Full Text Available Abstract This study aims to evaluate the effect of environmental variability on the growth and survival of the subtropical and tropical mussels Perna perna and Perna viridis at four different culture depths in the Gulf of Cariaco during an annual cycle. Juveniles of P. perna (39.1±1.88 mm in shell length and P. viridis (36.7±1.87 mm were sown on nylon ropes (3/4" and suspended from a raft at 1, 3, 6 and 9 m depths. Every six weeks, three replicates of each species were sampled (10 individuals per replicate at each depth. Growth parameters were determined: mass and shell length, dry mass of soft tissues as well as fouling and survival rates. Temperature, transparency, chlorophyll a, oxygen, salinity and particulate organic and inorganic matter were recorded at each culture depth for the purpose of relating growth and survival to environmental change. The results show that the growth of both species was linked to the environment, especially with regard to the influence of the food and temperature. A period of stagnant growth of P. perna was associated with the higher temperature and lower phytoplankton biomass that is characteristic of the season with prevalent water column stratification (August-November 2007. By contrast, the growth of P. viridis did not stagnate, although it was gradual and relatively lower. At the end, P. perna achieved higher growth rates than P. viridis. Possible culture strategies to improve the production of both mussel species are discussed.

  5. Crustacean fauna of a mussel cultivated raft system in the Black Sea

    Directory of Open Access Journals (Sweden)

    Murat Sezgin

    2013-06-01

    Full Text Available The aim of the current study was to make a faunistic analysis of the crustaceans associated with cultivated mussels grown on ropes. Mussel samples from 30 cm ropes were collected from rope-grown mussel beds by hand. The crustacean fauna associated with mussel population were quantified. The density of crustacean fauna associated with mussels was significantly greater within rope-grown mussel assemblages than on other biotopes around.

  6. Length- and weight-dependent clearance rates of juvenile mussels (

    NARCIS (Netherlands)

    Jacobs, P.; Troost, K.; Riegman, R.; van der Meer, J.

    2015-01-01

    Filtration capacity and feeding behaviour has been intensely studied for adult mussels (Mytilus edulis), but less information is available for juvenile mussels (1.5–25 mm, <1 year), especially in natural sea water. The recent introduction of mussel seed collectors in the Netherlands prompted the

  7. Testing of five methods for the control of zebra mussels in cooling circuits of power plants located on the Moselle river

    International Nuclear Information System (INIS)

    Khalanski, M.

    1993-10-01

    Bioassays have been conducted on site at the Cattenom nuclear power plant located on the Moselle River (in northeast France) to control mussels in auxiliary plant circuits. During the course of a two-year program, five methods were tested: - thermal treatment (33 deg to 40 deg C), - high dosage chlorination (> 50 ppm), - low dosage chlorine dioxide, - potassium salt (KCI > 100 ppm), - one organic compound (Mexel 432). This note presents a comparison of the treatments shown to be most effective, on the basis of technical feasibility, cost and environmental acceptability. (author). 8 figs., 10 refs., 3 tabs

  8. Mitigation of Syngas Cooler Plugging and Fouling

    Energy Technology Data Exchange (ETDEWEB)

    Bockelie, Michael J. [Reaction Engineering International, Salt Lake City, UT (United States)

    2015-06-29

    This Final Report summarizes research performed to develop a technology to mitigate the plugging and fouling that occurs in the syngas cooler used in many Integrated Gasification Combined Cycle (IGCC) plants. The syngas cooler is a firetube heat exchanger located downstream of the gasifier. It offers high thermal efficiency, but its’ reliability has generally been lower than other process equipment in the gasification island. The buildup of ash deposits that form on the fireside surfaces in the syngas cooler (i.e., fouling) lead to reduced equipment life and increased maintenance costs. Our approach to address this problem is that fouling of the syngas cooler cannot be eliminated, but it can be better managed. The research program was funded by DOE using two budget periods: Budget Period 1 (BP1) and Budget Period 2 (BP2). The project used a combination of laboratory scale experiments, analysis of syngas cooler deposits, modeling and guidance from industry to develop a better understanding of fouling mechanisms and to develop and evaluate strategies to mitigate syngas cooler fouling and thereby improve syngas cooler performance. The work effort in BP 1 and BP 2 focused on developing a better understanding of the mechanisms that lead to syngas cooler plugging and fouling and investigating promising concepts to mitigate syngas cooler plugging and fouling. The work effort focused on the following: • analysis of syngas cooler deposits and fuels provided by an IGCC plant collaborating with this project; • performing Jet cleaning tests in the University of Utah Laminar Entrained Flow Reactor to determine the bond strength between an ash deposit to a metal plate, as well as implementing planned equipment modifications to the University of Utah Laminar Entrained Flow Reactor and the one ton per day, pressurized Pilot Scale Gasifier; • performing Computational Fluid Dynamic modeling of industrially relevant syngas cooler configurations to develop a better

  9. Zeta-potential of fouled thin film composite membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, K.; Hachisuka, H.; Nakamura, T. [Nitto denko Corp., Ibaraki, (Japan); Kimura, S. [Kogakuin University, Tokyo (Japan). Dept. of Environ. Chemical Engineering; Ueyama, K. [Osaka University, Osaka (Japan). Dept. of Chemical Engineering

    1999-10-01

    The surface zeta-potential of a cross-linked polyamide thin film composite reverse osmosis membrane was measured using an electrophoresis method. It was confirmed that this method could be effectively applied to analyze the fouling of such membranes. It is known that the water flux of membranes drastically decreases as a result of fouling by surfactants. Although the surfactants adsorbed on reverse osmosis membranes could not be detected by conventional methods such as SEM, EDX and FT-IR, their presence could be clarified by the profile measurements of the surface zeta-potential. The profiles of the membrane surface zeta-potentials changed to more positive values in the measured pH range as a result of fouling by cationic or amphoteric surfactants. This measuring method of surface zeta-potentials allowed us to analyze a very small amount of fouling of a thin film composite reverse osmosis membrane. This method could be used to analyze the fouled surface of the thin film composite reverse osmosis membrane which is used for production of ultrapure water and shows a remarkable decrease in flux. It also became clear that this method is easy and effective for the reverse osmosis membrane surface analysis of adsorbed materials such as surfactants. (author)

  10. Molecular phylogeny of equine herpesvirus 1 isolates from onager, zebra and Thomson's gazelle.

    Science.gov (United States)

    Ghanem, Y M; Fukushi, H; Ibrahim, E S M; Ohya, K; Yamaguchi, T; Kennedy, M

    2008-01-01

    Viruses related to equine herpesvirus type 1 (EHV-1) were isolated from an aborted fetus of an onager (Equus hemionus) in 1984, an aborted fetus of Grevy's zebra (Equus grevyi) in 1984 and a Thomson's gazelle (Gazella thomsoni) with nonsuppurative encephalitis in 1996, all in the USA. The mother of the onager fetus and the gazelle were kept near plains zebras (Equus burchelli). In phylogenetic trees based on the nucleotide sequences of the genes for glycoproteins B (gB), I (gI), and E (gE), and teguments including ORF8 (UL51), ORF15 (UL45), and ORF68 (US2), the onager, Grevy's zebra and gazelle isolates formed a genetic group that was different from several horse EHV-1 isolates. Within this group, the onager and gazelle isolates were closely related, while the Grevy's zebra isolate was distantly related to these two isolates. The epizootiological origin of the viruses is discussed.

  11. Recognition and Reconstruction of Zebra Crossings on Roads from Mobile Laser Scanning Data

    Directory of Open Access Journals (Sweden)

    Lin Li

    2016-07-01

    Full Text Available Zebra crossings provide guidance and warning to pedestrians and drivers, thereby playing an important role in traffic safety management. Most previous studies have focused on detecting zebra stripes but have not provided full information about the areas, which is critical to both driver assistance systems and guide systems for blind individuals. This paper presents a stepwise procedure for recognizing and reconstructing zebra crossings using mobile laser scanning data. First, we propose adaptive thresholding based on road surface partitioning to reduce the impact of intensity unevenness and improve the accuracy of road marking extraction. Then, dispersion degree filtering is used to reduce the noise. Finally, zebra stripes are recognized according to the rectangular feature and fixed size, which is followed by area reconstruction according to arrangement patterns. We test our method on three datasets captured by an Optech Lynx mobile mapping system. The total recognition rate of 90.91% demonstrates the effectiveness of the method.

  12. Process in Developing Zebra fish Laboratory at Malaysian Nuclear Agency for Toxicology Studies

    International Nuclear Information System (INIS)

    Fazliana Mohd Saaya; Mohd Noor Hidayat Adenan; Anee Suryani Sued

    2015-01-01

    Toxicology is a branch of the very important especially in determining the safety and effectiveness of herbal products to avoid any side effects to the user. Currently, toxicity tests conducted in the laboratory is testing the toxicity of shrimp, tests on cell cultures and experimental animal tests on the rats. One of the most recent exam easier and can reduce the use of experimental rats was testing on zebra fish fish. Fish zebra fish Danio rerio, suitable for the study of toxicity, teratogenicity, genetic, oncology and neurobiology. Zebra fish system of aquarium fish zebra fish system has been in Nuclear Malaysia since 2013 but has not yet fully operational due to several factors and is in the process of moving into a new laboratory which systematically and in accordance with the enabling environment for care. The development of a new fully equipped laboratory is expected to benefit all for use in research. (author)

  13. Seasonal variations in fouling diatom communities on the Yantai coast

    Science.gov (United States)

    Yang, Cuiyun; Wang, Jianhua; Yu, Yang; Liu, Sujing; Xia, Chuanhai

    2015-03-01

    Fouling diatoms are a main component of biofilm, and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater, on the Yantai coast, northern Yellow Sea, China, using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3, 7, 14, and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca, Nitzschia, Navicula, Amphora, Gomphonema, and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions, we found that Cylindrotheca grew very fast, which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.

  14. Monitoring PAH contamination in water: Comparison of biological and physico-chemical tools

    International Nuclear Information System (INIS)

    Bourgeault, A.; Gourlay-Francé, C.

    2013-01-01

    The suitability of biological methods and chemical-based passive samplers to determine exposure to PAHs was tested by deploying zebra mussels and SPMDs along the Seine River over 11 months. The concentration of 13 PAHs was analyzed every month in both water and mussels. The sum of the PAH concentrations in mussels, initially at 299 ng g dry wt −1 , reached 2654, 3972 and 3727 ng g −1 at the end of exposure in the three sampling points taken through the river. The respective SPMD-available concentrations of TPAHs reached 9, 52 and 34 ng L −1 . Results showed seasonal variations of total PAH concentrations in the mussels, characterized by a decrease during spawning. The non-achievement of steady state concentration that was observed in mussels may be accounted for by the temporal variation of environmental concentrations. Thus, a bioaccumulation model based on kinetic rather than simple equilibrium partitioning was found to be more appropriate to describe PAH content in mussels. Moreover, biodynamic kinetic modeling proved useful to better understand the uptake and loss processes of pyrene. It clearly shows that these processes are markedly influenced by the biological state of the zebra mussels. The most realistic hypothesis is that the temporal variation of the biodynamic parameters may originate from a decrease of the mussels' metabolization of PAHs during spawning. Since SPMD passive samplers cannot integrate such biological factors, they are poor predictors of PAH bioavailability in mussels. - Highlights: • PAH contamination was monitored by deploying mussels and SPMDs over 11 months along the Seine River. • 5–6 ring PAHs which could not be quantified in spot samples, were measured in SPMDs. • PAH concentrations in the mussels decreased during spawning. • Temporal variation of bioaccumulated PAH may originate from a decrease of the mussels' metabolism during spawning. • Biodynamic model was allowed to explain the bioaccumulation

  15. Monitoring PAH contamination in water: Comparison of biological and physico-chemical tools

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeault, A., E-mail: bourgeault@ensil.unilim.fr; Gourlay-Francé, C.

    2013-06-01

    The suitability of biological methods and chemical-based passive samplers to determine exposure to PAHs was tested by deploying zebra mussels and SPMDs along the Seine River over 11 months. The concentration of 13 PAHs was analyzed every month in both water and mussels. The sum of the PAH concentrations in mussels, initially at 299 ng g{sub dry} {sub wt}{sup −1}, reached 2654, 3972 and 3727 ng g{sup −1} at the end of exposure in the three sampling points taken through the river. The respective SPMD-available concentrations of TPAHs reached 9, 52 and 34 ng L{sup −1}. Results showed seasonal variations of total PAH concentrations in the mussels, characterized by a decrease during spawning. The non-achievement of steady state concentration that was observed in mussels may be accounted for by the temporal variation of environmental concentrations. Thus, a bioaccumulation model based on kinetic rather than simple equilibrium partitioning was found to be more appropriate to describe PAH content in mussels. Moreover, biodynamic kinetic modeling proved useful to better understand the uptake and loss processes of pyrene. It clearly shows that these processes are markedly influenced by the biological state of the zebra mussels. The most realistic hypothesis is that the temporal variation of the biodynamic parameters may originate from a decrease of the mussels' metabolization of PAHs during spawning. Since SPMD passive samplers cannot integrate such biological factors, they are poor predictors of PAH bioavailability in mussels. - Highlights: • PAH contamination was monitored by deploying mussels and SPMDs over 11 months along the Seine River. • 5–6 ring PAHs which could not be quantified in spot samples, were measured in SPMDs. • PAH concentrations in the mussels decreased during spawning. • Temporal variation of bioaccumulated PAH may originate from a decrease of the mussels' metabolism during spawning. • Biodynamic model was allowed to explain

  16. Fouling Kinetics and Associated Dynamics of Structural Modifications

    DEFF Research Database (Denmark)

    Jacob, Jerome; Prádanos, Pedro; Calvo, J. I.

    1998-01-01

    It is shown that the fouling behaviour of microfiltration membranes does not agree within all the time ranges of any of the commonly used membrane blocking models (i.e. complete, standard, intermediate or cake blocking). The resulting experimental kinetics of flux decline do not fit to only one...... of these models, but according to a successive or simultaneous coexistence of two or more of them. This is studied by analysing the structural modifications associated with the fouling kinetics. To achieve this goal, here we analyse the dynamical changes on the structure of four microporous membranes made...... by Sartorius (ST02 and ST045, neutral) and Spectrum (SP02 and SP045, positively charged) when fouled by permeating a protein aqueous solution (bovine serum albumin (BSA) at 1 g l(-1)) under 10 kPa in a dead-end device. The structure after different fouling times is obtained by using an extended bubble point...

  17. The Thermal Hydraulics of Tube Support Fouling in Nuclear Steam Generators

    International Nuclear Information System (INIS)

    Rummens, Helena E.C.; Rogers, J.T.; Turner, C.W.

    2004-01-01

    It is hypothesized that the thermal-hydraulic environment plays a role in the fouling of tube supports in nuclear steam generators. Experiments were performed to simulate the thermal-hydraulic environment near various designs of supports. Pressure loss, local velocity, turbulence intensity, and local void fraction were measured to characterize the effect of the support. Fouling mechanisms specific to supports were inferred from these experimental data and from actual steam generator inspection results. An analytical model was developed to predict the rate of particulate deposition on the supports, to better understand the complex processes involved.This paper presents the following set of tools for assessing the fouling propensity of a given support design: (1) proposed fouling mechanisms, (2) criteria for support fouling propensity, (3) correlation of fouling with parameters such as mass flux and quality, (4) descriptions of experimental tools such as flow visualization and measurement of pressure-loss profiles, and (5) analytical tools.An important conclusion from this and our previous work is that the fouling propensity is greater with broached support plates, both trefoil and quatrefoil, than with lattice bar supports and formed bar supports, in which significant cross flows occur

  18. Effect of fouling on removal of trace organic compounds by nanofiltration

    Directory of Open Access Journals (Sweden)

    S. Hajibabania

    2011-12-01

    Full Text Available The fate of chemical of concern is not yet fully understood during treatment of impaired waters. The aim of this paper is to assess the impact of different organic-based fouling layers on the removal of a large range of trace organics. Both model and real water samples (mixed with trace organic contaminants at environmental concentration of 2 μg l−1 were used to simulate fouling in nanofiltration under controlled environment. The new and fouled membranes were systematically characterised for surface charge, hydrophobicity and roughness. It was observed that fouling generally reduced the membrane surface charge; however, the alterations of the membrane hydrophobicity and surface roughness were dependent on the foulants composition. The rejection of charged trace organics was observed to be improved due to the increased electrostatic repulsion by fouled membranes and the adsorption of the trace organic chemicals onto organic matters. On the other hand, the removal of nonionic compounds decreased when fouling occurred, due to the presence of cake enhanced concentration polarization. The fouling layer structure was found to play an important role in the rejection of the trace organic compounds.

  19. Characterization of Irreversible Fouling after Ultrafiltration of Thermomechanical Pulp Mill Process Water

    DEFF Research Database (Denmark)

    Thuvander, Johan; Zarebska, Agata; Hélix-Nielsen, Claus

    2018-01-01

    process streams is fouling of the membranes. Fouling not only increases operating costs but also reduces the operating time of the membrane plant. When optimizing the membrane cleaning method, it is important to know which compounds cause the fouling. In this work fouling of an ultrafiltration membrane...... was studied. The fouling propensity of untreated process water and microfiltrated process water was compared. Fouled membranes were analyzed using scanning electron microscopy and attenuated total reflection Fourier transform infrared spectrometry. Acid hydrolysis of membranes exposed to untreated process......Large volumes of wastewater with dissolved wood components are treated in wastewater treatment plants at thermomechanical pulp mills. It has been shown previously that hemicelluloses in these wastewater streams can be recovered by membrane filtration. A serious obstacle when treating lignocellulose...

  20. Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

    KAUST Repository

    Jamaly, Sanaa

    2011-12-01

    Membrane fouling is a challenging process for the ultrafiltration membrane during wastewater treatment. This research paper determines the organic character of foulants of different kinds of wastewater before and after adding some ion exchange resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary wastewater effluents were treated using ultrafiltration membrane. To reduce fouling, pretreatment using some adsorbents were used in the study. Six ion exchange resins out of twenty were chosen to compare the effect of adsorbents on fouling membrane. Based on the percent of dissolved organic carbon’s removal, three adsorbents were determined to be the most efficient (DOWEX Marathon 11 anion exchange resin, DOWEX Optipore SD2 polymeric adsorbent, and DOWEX PSR2 anion exchange), and three other ones were determined to the least efficient (DOWEX Marathon A2 anion exchange resin, DOWEX SAR anion exchange resin, and DOWEX Optipore L493 polymeric adsorbent). Organic characterization for feed, permeate, and backwash samples were tested using LC-OCD and TOC to better understand the characteristics of foulants to prevent ultrafiltration membrane fouling. The results suggested that the polymeric ion exchange resin, DOWEX SD2, reduced fouling potential for both treated wastewaters. All the six ion exchange resins removed more humic fraction than other organic fractions in different percent, so this fraction is not the main for cause for UF membrane fouling. The fouling of colloids was tested before and after adding calcium. There is a severe fouling after adding Ca2+ to effluent colloids.

  1. Large-Scale Spatial Dynamics of Intertidal Mussel (

    NARCIS (Netherlands)

    Folmer, E.O.; Drent, J.; Troost, K.; Büttger, H.; Dankers, N.; Jansen, J.; van Stralen, M.; Millat, G.; Herlyn, M.; Philippart, C.J.M.

    2014-01-01

    Intertidal blue mussel beds are important for the functioning and community composition of coastal ecosystems. Modeling spatial dynamics of intertidal mussel beds is complicated because suitable habitat is spatially heterogeneously distributed and recruitment and loss are hard to predict. To get

  2. Ultrasonic control of ceramic membrane fouling: Effect of particle characteristics.

    Science.gov (United States)

    Chen, Dong; Weavers, Linda K; Walker, Harold W

    2006-02-01

    In this study, the effect of particle characteristics on the ultrasonic control of membrane fouling was investigated. Ultrasound at 20 kHz was applied to a cross-flow filtration system with gamma-alumina membranes in the presence of colloidal silica particles. Experimental results indicated that particle concentration affected the ability of ultrasound to control membrane fouling, with less effective control of fouling at higher particle concentrations. Measurements of sound wave intensity and images of the cavitation region indicated that particles induced additional cavitation bubbles near the ultrasonic source, which resulted in less turbulence reaching the membrane surface and subsequently less effective control of fouling. When silica particles were modified to be hydrophobic, greater inducement of cavitation bubbles near the ultrasonic source occurred for a fixed concentration, also resulting in less effective control of fouling. Particle size influenced the cleaning ability of ultrasound, with better permeate recovery observed with larger particles. Particle size did not affect sound wave intensity, suggesting that the more effective control of fouling by large particles was due to greater lift and cross-flow drag forces on larger particles compared to smaller particles.

  3. The impact of fouling on performance evaluation of evaporative coolers and condensers

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, B.A.; Zubair, S.M. [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia). Mechanical Engineering Dept.

    2005-11-15

    Fouling of evaporative cooler and condenser tubes is one of the most important factors affecting their thermal performance, which reduces effectiveness and heat transfer capability with time. In this paper, the experimental data on fouling reported in the literature are used to develop a fouling model for this class of heat exchangers. The model predicts the decrease in heat transfer rate with the growth of fouling. A detailed model of evaporative coolers and condensers, in conjunction with the fouling model, is used to study the effect of fouling on the thermal performance of these heat exchangers at different air inlet wet bulb temperatures. The results demonstrate that fouling of tubes reduces gains in performance resulting from decreasing values of air inlet wet bulb temperature. It is found that the maximum decrease in effectiveness due to fouling is about 55 and 78% for the evaporative coolers and condensers, respectively, investigated in this study. For the evaporative cooler, the value of process fluid outlet temperature T{sub p,out} varies by 0.66% only at the clean condition for the ambient wet bulb temperatures considered. (author)

  4. Anti-fouling properties of Fab’ fragments immobilized on silane-based adlayers

    International Nuclear Information System (INIS)

    Crivianu-Gaita, Victor; Romaschin, Alexander; Thompson, Michael

    2015-01-01

    Highlights: • Simple and mixed adlayers formed with Fab’ linker and/or spacers. • Binding of Fab’ fragments through TUBTS linker resulted in oriented immobilization. • Immobilized Fab’ fragments have inherent anti-fouling character. • Up to 80% fouling reduction when Fab’ fragments introduced to surfaces. • Used the minimally fouling surfaces to detect a cancer biomarker (PTHrP) in serum. - Graphical abstract: Biosensors require surfaces that are highly specific towards the target analyte and that are minimally fouling. However, surface tuning to minimize fouling is a difficult task. The last decade has seen an increase in the use of immobilized antigen-binding antibody fragments (Fab’) in biosensors. One Fab’ linker compound S-(11-trichlorosilyl-undecanyl)-benzothiosulfonate (TUBTS) and three spacers were used to create the silane-based adlayers. The ultra-high frequency electromagnetic piezoelectric acoustic sensor (EMPAS) was used to gauge the fouling properties of the various surfaces using bovine serum albumin (BSA), goat IgG, and mouse serum. X-ray photoelectron spectroscopy (XPS), contact angle, and atomic force microscopy (AFM) were employed to characterize the surfaces. It was discovered that immobilized oriented Fab’ fragments reduced the fouling levels of surfaces up to 80% compared to the surfaces without fragments. An explanation for this phenomenon is that the antibody fragments increase the hydration of the surfaces and aid in the formation of an anti-fouling water barrier. The anti-fouling effect of the Fab’ fragments is at its maximum when there is an even distribution of fragments across the surfaces. Finally, using Fab’-covered surfaces, a cancer biomarker was detected from serum, showing the applicability of this work to the field of biodetection. - Abstract: Biosensors require surfaces that are highly specific towards the target analyte and that are minimally fouling. However, surface tuning to minimize fouling is a

  5. Anti-fouling properties of Fab’ fragments immobilized on silane-based adlayers

    Energy Technology Data Exchange (ETDEWEB)

    Crivianu-Gaita, Victor [Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6 (Canada); Romaschin, Alexander [Clinical Biochemistry, St. Michael' s Hospital, Toronto, ON M5B 1W8 (Canada); Thompson, Michael, E-mail: mikethom@chem.utoronto.ca [Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6 (Canada)

    2015-12-30

    Highlights: • Simple and mixed adlayers formed with Fab’ linker and/or spacers. • Binding of Fab’ fragments through TUBTS linker resulted in oriented immobilization. • Immobilized Fab’ fragments have inherent anti-fouling character. • Up to 80% fouling reduction when Fab’ fragments introduced to surfaces. • Used the minimally fouling surfaces to detect a cancer biomarker (PTHrP) in serum. - Graphical abstract: Biosensors require surfaces that are highly specific towards the target analyte and that are minimally fouling. However, surface tuning to minimize fouling is a difficult task. The last decade has seen an increase in the use of immobilized antigen-binding antibody fragments (Fab’) in biosensors. One Fab’ linker compound S-(11-trichlorosilyl-undecanyl)-benzothiosulfonate (TUBTS) and three spacers were used to create the silane-based adlayers. The ultra-high frequency electromagnetic piezoelectric acoustic sensor (EMPAS) was used to gauge the fouling properties of the various surfaces using bovine serum albumin (BSA), goat IgG, and mouse serum. X-ray photoelectron spectroscopy (XPS), contact angle, and atomic force microscopy (AFM) were employed to characterize the surfaces. It was discovered that immobilized oriented Fab’ fragments reduced the fouling levels of surfaces up to 80% compared to the surfaces without fragments. An explanation for this phenomenon is that the antibody fragments increase the hydration of the surfaces and aid in the formation of an anti-fouling water barrier. The anti-fouling effect of the Fab’ fragments is at its maximum when there is an even distribution of fragments across the surfaces. Finally, using Fab’-covered surfaces, a cancer biomarker was detected from serum, showing the applicability of this work to the field of biodetection. - Abstract: Biosensors require surfaces that are highly specific towards the target analyte and that are minimally fouling. However, surface tuning to minimize fouling is a

  6. Nanoparticle fouling and its combination with organic fouling during forward osmosis process for silver nanoparticles removal from simulated wastewater

    Science.gov (United States)

    Zhao, Yanxiao; Wang, Xinhua; Wang, Zhiwei; Li, Xiufen; Ren, Yueping

    2016-05-01

    The increasing and wide application of silver nanoparticles (Ag NPs) has resulted in their appearance in wastewater. In consideration of their potential toxicity and environmental impacts, it is necessary to find effective technology for their removal from wastewater. Here, forward osmosis (FO) membrane was applied for Ag NPs removal from wastewater, and single and combined fouling of nanoparticles and organic macromolecules were further investigated during the FO process. The findings demonstrated that FO membrane can effectively remove Ag NPs from wastewater due to its high rejection performance. Fouling tests indicated that water flux declined appreciably even at the beginning of the single Ag NPs fouling test, and more remarkable flux decline and larger amounts of deposited Ag NPs were observed with an increase of Ag NPs concentration. However, the addition of bovine serum albumin (BSA) could effectively alleviate the FO membrane fouling induced by Ag NPs. The interaction between Ag NPs and BSA was responsible for this phenomenon. BSA can easily form a nanoparticle-protein corona surrounded nanoparticles, which prevented nanoparticles from aggregation due to the steric stabilization mechanism. Furthermore, the interaction between BSA and Ag NPs occurred not only in wastewater but also on FO membrane surface.

  7. Hydrocarbon uptake and loss by the mussel Mytilus edulis

    Energy Technology Data Exchange (ETDEWEB)

    Fossato, V U; Canzonier, W J

    1976-01-01

    The dynamics of accumulation and elimination of hydrocarbons by the blue mussel Mytilus edulis were studied in a continuous-flow system. Mussels were exposed for as long as 41 days to 200 to 400 ..mu..g/l of diesel fuel adsorbed on kaolin particles. Hydrocarbons were accumulated in the tissues in excess of 1000 times the exposure levels. Upon termination of dosing, the mussels exhibited a rather rapid loss of hydrocarbons for the first 15 to 20 days (biological half-life = 2.7 to 3.5 days). Subsequently, however, elimination was reduced to a minimum and a considerable fraction of the hydrocarbons could be recovered from the tissues after as long as 32 days of depuration. The mussels exhibited definite signs of physiological stress due to chronic exposure to diesel fuel, although recovery was rapid upon termination of dosing. It is concluded that mussels could be utilized as a test organism for monitoring long-term hydrocarbon pollution in marine waters. The implications for the mussel culture industry are discussed.

  8. Long-term dynamics of the state of the fouling community in the Odessa Bay (Black Sea

    Directory of Open Access Journals (Sweden)

    A. Y. Varigin

    2017-04-01

    Full Text Available This article examines the long-term dynamics of the qualitative and quantitative characteristics of the coastal fouling community of OdessaBay(Black Sea for the last 40 years. It compares the data on this community obtained by different researchers in 1976, 1994 and 2016 . The number of species included in the fouling community decreased from 103 (1976 to 43 (1994 and then rose to 62 by 2016. As a possible reason for this reduction in the species composition of the community the influence of large-scale anthropogenic eutrophication, which was already strongly evident in the north-western part of the Black Seain the 1970s, is proposed. This phenomenon was accompanied by periodic outbreaks of mass abundance of planktonic algae, secondary water pollution, the development of hypoxia and a frequent suffocation effect on the benthos, which caused the disappearance from the community of 41 species of invertebrates. The reduction in the number of species affected representatives of the following taxons: Polychaeta, Amphipoda, Gastropoda and Bivalvia. Currently, the core of the community includes the same species of invertebrates as in the past. It is based on Bivalvia mussels Mytilus galloprovincialis. Among the attached forms , Mytilaster lineatus (Bivalvia and Amphibalanus improvisus (Cirripedia play a leading role, and among mobile – representatives of Polychaeta, Isopoda, Amphipoda and Gastropoda. It is shown that 10 of the 25 species, recorded the first time for this community in the 1970s, have become abundant in modern conditions. The primacy in the relative density in the composition of the community at the present time has passed from the amphipod crustaceans to bivalve molluscs. The highest relative biomass, both in the past and in the present-day conditions was observed in representatives of Bivalvia. The structure of the resistance of the fouling community to the effects of unstable environmental factors specific to the coastal zone is

  9. Multiyear Synthesis of the Macroinvertebrate Component From 1992 to 2002 for the Long Term Resource Monitoring Program

    National Research Council Canada - National Science Library

    Sauer, Jennifer

    2004-01-01

    ...) were added to the sampling design in 1993 and zebra mussels (Dreissena Polymorpha) were added in 1995. Sampling was based on a stratified random design and conducted at approximately 125 sites per study area...

  10. New insights into controlling tube-bundle fouling using alternative amines

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K. [Atomic Energy of Canada Ltd. (Canada); Frattini, P.L. [Electric Power Research Inst. (United States)

    2002-07-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

  11. New insights into controlling tube-bundle fouling using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K.; Frattini, P.L.

    2002-01-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

  12. Glacial history of the European marine mussels

    NARCIS (Netherlands)

    Smietanka, B.; Burzynski, A.; Hummel, H.; Wenne, R.

    2014-01-01

    Mussels of the genus Mytilus have been used to assess the circumglacial phylogeography of the intertidal zone. These mussels are representative components of the intertidal zone and have rapidly evolving mitochondrial DNA, suitable for high resolution phylogeographic analyses. In Europe, the three

  13. Effect of resins of heat exchanger fouling by asphaltene-containing oils

    Energy Technology Data Exchange (ETDEWEB)

    Al-Atar, E.; Watkinson, A.P. [British Columbia Univ., Dept. of Chemical and Bio-Resource Engineering, Vancouver, BC (Canada)

    1999-07-01

    The effects of resins on the thermal fouling of asphaltene containing oils in heat exchangers was investigated as well as the nature of the deposits. Building on previous research, a sample of de-asphalted vacuum bottoms (DAO), serving as a source of natural resins, heavy oil (HO) and fuel oil was used to investigate the effects of resin concentration on the rate of thermal fouling. The conditions of the study included: fluid circulation through the UBC annular fouling test section for up to 30 hour periods, monitoring of thermal fouling by measurement, and nitrogen atmospheres at a bulk temperature of 85 degrees C, a bulk velocity of 0.85 am/s, and a pressure of 410 kPa. Physical and chemical characterization of the deposits was affected, and filtration at the bulk temperature before and after a run was used to determine the occurrence of fine solids in the fluid. The rate of fouling generally decreased tending generally towards asymptotic behavior in the limit, and after one day Rf values up to 0.3 m2K/kW occurred with severe fouling. An increase in the fouling rate occurred with increased DAO concentration in the mixture, at a fixed heavy oil concentration of 5 weight percent, and the relation between Asomaning's colloidal instability index and the trends in fouling rate was not observed, although there were some indications of reduced fouling as there was an increase in the ratio of resins to asphaltenes, however, blends of the DAO-HO-FO helped to control the concentration of asphaltenes and resins that are possible. (Abstract only).

  14. New insights into controlling tube-bundle fouling using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Frattini, P.L.; Fruzzetti, K.

    2002-01-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. Atomic Energy of Canada Limited (AECL) and Electric Power Research Institute (EPRI) have been collaborating in an extensive investigation of the effectiveness of amines at controlling the rate of tube-bundle fouling under SG operating conditions. Tests have been performed using a radiotracing technique in a high-temperature fouling loop facility at Chalk River Laboratories operated by AECL. This investigation has provided new insights into the role played by the amine in determining the rate of tube-bundle fouling in the SG. These insights are being used by AECL and EPRI to develop criteria for the selection of an amine that has optimum properties for both corrosion control and deposit control in the secondary heat transport system. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of

  15. Review of toxic episodes and management strategies in the Danish mussel production

    DEFF Research Database (Denmark)

    Jørgensen, Kevin; Andersen, Per; Thorbjørnsen, Bjarne Ring

    Denmark has in many years been one of the world’s main producers of blue mussels caught from natural banks. The Danish mussel aquaculture sector is now growing. The Danish production areas have been regarded as “low risk” areas with respect to toxic algae and occurrence of marine biotoxins....... The change to more production of cultured mussel results in higher risk for occurrence of marine biotoxins because of the closer interaction between toxic algae and mussels. Results showing the difference between content of marine biotoxins in bottom mussel and cultured mussel from the same production areas...... cell toxicity of potential toxic algae in combination with algae cell number and mussel toxicity for opening or closing of production areas....

  16. Model track studies on fouled ballast using ground penetrating radar and multichannel analysis of surface wave

    Science.gov (United States)

    Anbazhagan, P.; Lijun, Su; Buddhima, Indraratna; Cholachat, Rujikiatkamjorn

    2011-08-01

    Ballast fouling is created by the breakdown of aggregates or outside contamination by coal dust from coal trains, or from soil intrusion beneath rail track. Due to ballast fouling, the conditions of rail track can be deteriorated considerably depending on the type of fouling material and the degree of fouling. So far there is no comprehensive guideline available to identify the critical degree of fouling for different types of fouling materials. This paper presents the identification of degree of fouling and types of fouling using non-destructive testing, namely seismic surface-wave and ground penetrating radar (GPR) survey. To understand this, a model rail track with different degree of fouling has been constructed in Civil engineering laboratory, University of Wollongong, Australia. Shear wave velocity obtained from seismic survey has been employed to identify the degree of fouling and types of fouling material. It is found that shear wave velocity of fouled ballast increases initially, reaches optimum fouling point (OFP), and decreases when the fouling increases. The degree of fouling corresponding after which the shear wave velocity of fouled ballast will be smaller than that of clean ballast is called the critical fouling point (CFP). Ground penetrating radar with four different ground coupled antennas (500 MHz, 800 MHz, 1.6 GHz and 2.3 GHz) was also used to identify the ballast fouling condition. It is found that the 800 MHz ground coupled antenna gives a better signal in assessing the ballast fouling condition. Seismic survey is relatively slow when compared to GPR survey however it gives quantifiable results. In contrast, GPR survey is faster and better in estimating the depth of fouling.

  17. CFD modeling of fouling in crude oil pre-heaters

    International Nuclear Information System (INIS)

    Bayat, Mahmoud; Aminian, Javad; Bazmi, Mansour; Shahhosseini, Shahrokh; Sharifi, Khashayar

    2012-01-01

    Highlights: ► A conceptual CFD-based model to predict fouling in industrial crude oil pre-heaters. ► Tracing fouling formation in the induction and developing continuation periods. ► Effect of chemical components, shell-side HTC and turbulent flow on the fouling rate. - Abstract: In this study, a conceptual procedure based on the computational fluid dynamic (CFD) technique has been developed to predict fouling rate in an industrial crude oil pre-heater. According to the developed CFD concept crude oil was assumed to be composed of three pseudo-components comprising of petroleum, asphaltene and salt. The binary diffusion coefficients were appropriately categorized into five different groups. The species transport model was applied to simulate the mixing and transport of chemical species. The possibility of adherence of reaction products to the wall was taken into account by applying a high viscosity for the products in competition with the shear stress on the wall. Results showed a reasonable agreement between the model predictions and the plant data. The CFD model could be applied to new operating conditions to investigate the details of the crude oil fouling in the industrial pre-heaters.

  18. Amphiphilic polymer based on fluoroalkyl and PEG side chains for fouling release coating

    Science.gov (United States)

    Cong, W. W.; Wang, K.; Yu, X. Y.; Zhang, H. Q.; Lv, Z.; Gui, T. J.

    2017-12-01

    Under static conditions, fouling release coating could not express good release property to marine organisms. Amphiphilic polymer with mixture of fluorinated monomer and short side group of polyethylene glycol (PEG) was synthesized. And also we studied the ability of amphiphilic polymer to influence the surface properties and how it controlled the adhesion of marine organisms to coated surfaces. By incorporating fluorinated monomer and PEG side chain into the polymer, the effect of incorporating both polar and non-polar groups on fouling-release coating could be studied. The dry surface was characterized by three-dimensional digital microscopy and scanning electron microscopy (SEM), and the morphology of the amphiphilic fouling release coating showed just like flaky petal. The amphiphilic polymer in fouling release coating tended to reconstruct in water, and the ability was examined by static contact angle, which was smaller than the PDMS (polydimethylsiloxane) fouling release coating. Also surface energy was calculated by three solvents, and surface energy of amphiphilic fouling release coating was higher than that of the PDMS fouling release coating. To understand more about its fouling release property, seawater exposure method was adopted in gulf of Qingdao port. Fewer diatoms Navicula were found in biofilm after using amphiphilic fouling release coating. In general, coating containing both PEG and fluorinated side chain possessed certain fouling release property.

  19. Impact of effluent organic matter on low-pressure membrane fouling in tertiary treatment

    KAUST Repository

    Ayache, C.; Pidou, Marc; Croue, Jean-Philippe; Labanowski, Jé rô me; Poussade, Yvan; Tazi-Pain, Annie; Keller, Jurg R.; Gernjak, Wolfgang

    2013-01-01

    This study aims at comparing low-pressure membrane fouling obtained with two different secondary effluents at bench and pilot-scale based on the determination of two fouling indices: the total fouling index (TFI) and the hydraulically irreversible fouling index (HIFI). The main objective was to investigate if simpler and less costly bench-scale experimentation can substitute for pilot-scale trials when assessing the fouling potential of secondary effluent in large scale membrane filtration plants producing recycled water. Absolute values for specific flux and total fouling index for the bench-scale system were higher than those determined from pilot-scale, nevertheless a statistically significant correlation (r2 = 0.63, α = 0.1) was obtained for the total fouling index at both scales. On the contrary no such correlation was found for the hydraulically irreversible fouling index. Advanced water characterization tools such as excitation-emission matrix fluorescence spectroscopy (EEM) and liquid chromatography with organic carbon detection (LC-OCD) were used for the characterization of foulants. On the basis of statistical analysis, biopolymers and humic substances were found to be the major contribution to total fouling (r2 = 0.95 and r2 = 0.88, respectively). Adsorption of the low molecular weight neutral compounds to the membrane was attributed to hydraulically irreversible fouling (r2 = 0.67). © 2013 Elsevier Ltd.

  20. Impact of effluent organic matter on low-pressure membrane fouling in tertiary treatment

    KAUST Repository

    Ayache, C.

    2013-05-01

    This study aims at comparing low-pressure membrane fouling obtained with two different secondary effluents at bench and pilot-scale based on the determination of two fouling indices: the total fouling index (TFI) and the hydraulically irreversible fouling index (HIFI). The main objective was to investigate if simpler and less costly bench-scale experimentation can substitute for pilot-scale trials when assessing the fouling potential of secondary effluent in large scale membrane filtration plants producing recycled water. Absolute values for specific flux and total fouling index for the bench-scale system were higher than those determined from pilot-scale, nevertheless a statistically significant correlation (r2 = 0.63, α = 0.1) was obtained for the total fouling index at both scales. On the contrary no such correlation was found for the hydraulically irreversible fouling index. Advanced water characterization tools such as excitation-emission matrix fluorescence spectroscopy (EEM) and liquid chromatography with organic carbon detection (LC-OCD) were used for the characterization of foulants. On the basis of statistical analysis, biopolymers and humic substances were found to be the major contribution to total fouling (r2 = 0.95 and r2 = 0.88, respectively). Adsorption of the low molecular weight neutral compounds to the membrane was attributed to hydraulically irreversible fouling (r2 = 0.67). © 2013 Elsevier Ltd.

  1. Fouling in small hydro projects; Verschmutzung von Kleinwasserkraftwerken - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Abgottspon, A.; Staubli, T.

    2010-03-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at fouling problems encountered in small hydro installations. The report is based on ten interviews made with operators of small hydro power stations in Switzerland. A parallel project carried out in Germany is mentioned. A large variation in the degree of fouling in the various hydro power stations is noted. Sources such as leaves in autumn and algae are discussed, as are the various rinsing procedures used to clear the turbines of fouling. Power losses are discussed and measures that can be taken to prevent fouling are described. Measurements made at an installation in Freienstein, Switzerland, are presented and discussed. The report is completed with an appendix containing calculations, details on the Freienstein power plant and the results of interviews made with the ten hydro power installations examined.

  2. Polymeric membranes: surface modification for minimizing (bio)colloidal fouling.

    Science.gov (United States)

    Kochkodan, Victor; Johnson, Daniel J; Hilal, Nidal

    2014-04-01

    This paper presents an overview on recent developments in surface modification of polymer membranes for reduction of their fouling with biocolloids and organic colloids in pressure driven membrane processes. First, colloidal interactions such as London-van der Waals, electrical, hydration, hydrophobic, steric forces and membrane surface properties such as hydrophilicity, charge and surface roughness, which affect membrane fouling, have been discussed and the main goals of the membrane surface modification for fouling reduction have been outlined. Thereafter the recent studies on reduction of (bio)colloidal of polymer membranes using ultraviolet/redox initiated surface grafting, physical coating/adsorption of a protective layer on the membrane surface, chemical reactions or surface modification of polymer membranes with nanoparticles as well as using of advanced atomic force microscopy to characterize (bio)colloidal fouling have been critically summarized. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. WINTOF - A program to produce neutron spectra from Zebra time-of-flight experiments

    International Nuclear Information System (INIS)

    Marshall, J.

    1969-06-01

    This report describes a computer program, written for the Winfrith KDF9 computer, which is used to calculate the neutron energy spectrum in the Zebra reactor from neutron time-of-flight measurements using the Zebra Linac. The data requirements for the program are specified and an illustration of the final spectrum is included. (author)

  4. Mussel watch

    Science.gov (United States)

    Contamination of U.S. coastal areas may be decreasing as a result of environmental regulations that have banned or curtailed toxic chemicals, concludes a report by the National Oceanic and Atmospheric Administration. The report, “Recent Trends in Coastal Environmental Quality: Results from the Mussel Watch Project,” presents results of analyzing chemical concentrations found in mussel and oyster tissues collected every year since 1986.These mollusks are collected once a year at more than 240 sites nationwide and analyzed for over 70 polycyclic aromatic hydrocarbons, polychlorinated biphenyls, chlorinated pesticides, butyltins, and toxic trace elements such as copper, cadmium, and lead. The report states that from 1986 to 1993 there were many more decreases than increases in chemical concentrations in coastal regions. These decreasing trends were not unexpected; all of the monitored chlorinated hydrocarbons have been banned for use in the United States, and tributyltin has been banned as a biocide on recreational boats.

  5. Flux dependency of particulate/colloidal fouling in seawater reverse osmosis systems

    KAUST Repository

    Salinas Rodríguez, S. G.

    2012-01-01

    Fouling is the main operational problem in seawater reverse osmosis systems (SWRO). Particulate fouling is traditionally measured through the silt density index (SDI) and through the modified fouling index (MFI). In recent years, ultrafiltration membranes were used successfully at constant flux-MFI-UF-to measure particulate/colloidal fouling potential and tested in sea water applications. Furthermore, constant flux operation allows predicting the rate of fouling in RO systems. The objectives of this study are: (1) to measure the flux effect in MFI-UF with different membranes (100, 30 and 10 kDa) for raw seawater and pre-treated water before reverse osmosis in three different locations; (2) to study the particulate and colloidal fouling potential of seawater in reverse osmosis systems; (3) to project the increase in pressure due to cake resistance in reverse osmosis systems. In this research, flat ultrafiltration membranes (100, 50, 30 and 10 kDa) are used in a con- stant flux filtration mode to test and compare real seawaters from various locations (North and Mediterranean Sea) and from various full scale facilities including different pre-treatments (i.e., ultrafiltration and coagulation + dual media filtration). The operated fluxes range from 350 down to values close to real RO operation, 15l(m2h)-1. After each filtration test, the MFI-UF is calculated to assess the particulate fouling potential. The obtained results showed that: (1) the particulate and colloidal fouling potential is directly proportional to the applied flux during filtration. This proportionality is related to the compression of the cake deposit occurring at high flux values; (2) the higher the flux, the higher the required pressure, the less porous the cake and therefore the higher the specific cake resistance; (3) particulate and colloidal fouling potential of seawater is site specific and is influenced by pre-treatment. © 2012 Desalination Publications. All rights reserved.

  6. Dynamic coating of mf/uf membranes for fouling mitigation

    KAUST Repository

    Tabatabai, S. Assiyeh Alizadeh; Leiknes, TorOve

    2017-01-01

    A membrane system including an anti-fouling layer and a method of applying an anti-fouling layer to a membrane surface are provided. In an embodiment, the surface is a microfiltration (MF) or an ultrafiltration (UF) membrane surface. The anti

  7. The existence of microplastic in Asian green mussels

    Science.gov (United States)

    Khoironi, A.; Anggoro, S.; Sudarno

    2018-03-01

    Due to resistance of polymer as basic properties of plastic, several studies have been conducted to understand the fate of plastic debris in the marine environment. Degradation is the most important process to control distribution of plastic debris a long the marine environment until the existence of plastic in the food chain. The physical and chemical changes of plastic because of degradation process will lead to the release of polluted substances which eventually more toxic for the environment. Furthermore, when plastic degraded become a microplastic will lead to easy ingested by biotic such as mussell which commonly consumed by humans. The aim of this research was to investigate the concentration of microplastic adsorbed and ingested by mussels considering characteristic of sea water. About 30 samples have been collected from 3 different locations that is brackish water (31 ppb), high salinity (36 ppb) and low salinity (33 ppb) for measuring a number of microplastic in mussels on three different salinity. The result of microstructure analysis by microscope showed that mussel evaluated from the marine environment contaminated by microplastic with average size of 211.163 μm. In high salinity sea water, microplastic found in mussel was greater than low salinity and brackish water. The SEM/EDX analysis showed the presence of SIO2 0.14 % (w/w), Na2O 24.27 %(w/w) and Al2O3 0.27 % (w/w) in the microplastic obtained in the mussel indicating the components which are mostly found in the plastic industries. The amount of microplastic in mussell could be used as pollution indicator in the marine environmental by plastic waste.

  8. Foul or dive? Motor contributions to judging ambiguous foul situations in football

    NARCIS (Netherlands)

    Renden, P.G.; Kerstens, S.; Oudejans, R.R.D.; Canal Bruland, R.

    2014-01-01

    Football (soccer) referees frequently face situations in which they have to distinguish dives and fouls. Yet, little is known about the contributing factors that characterise the ability to judge these ambiguous situations correctly. To this end, in the current article we tested the hypothesis that

  9. Ecosystem transformations of the Laurentian Great Lake Michigan by nonindigenous biological invaders.

    Science.gov (United States)

    Cuhel, Russell L; Aguilar, Carmen

    2013-01-01

    Lake Michigan, a 58,000-km(2) freshwater inland sea, is large enough to have persistent basin-scale circulation yet small enough to enable development of approximately balanced budgets for water, energy, and elements including carbon and silicon. Introduction of nonindigenous species-whether through invasion, intentional stocking, or accidental transplantation-has transformed the lake's ecosystem function and habitat structure. Of the 79 nonindigenous species known to have established reproductive populations in the lake, only a few have brought considerable ecological pressure to bear. Four of these were chosen for this review to exemplify top-down (sea lamprey, Petromyzon marinus), middle-out (alewife, Alosa pseudoharengus), and bottom-up (the dreissenid zebra and quagga mussels, Dreissena polymorpha and Dreissena rostriformis bugensis, respectively) transformations of Lake Michigan ecology, habitability, and ultimately physical environment. Lampreys attacked and extirpated indigenous lake trout, the top predator. Alewives outcompeted native planktivorous fish and curtailed invertebrate populations. Dreissenid mussels-especially quagga mussels, which have had a much greater impact than the preceding zebra mussels-moved ecosystem metabolism basin-wide from water column to bottom dominance and engineered structures throughout the lake. Each of these non indigenous species exerted devastating effects on commercial and sport fisheries through ecosystem structure modification.

  10. Influence of Thermal Preparation Method on Mineral Composition of Mussels

    Directory of Open Access Journals (Sweden)

    Gheorghe Valentin GORAN

    2018-02-01

    Full Text Available This study focuses on evaluation of the effects of 3 different thermal preparation methods (boiling, roasting, microwaving on mineral concentrations of mussels from Bucharest market. The mineral content in raw and cooked mussel samples was evaluated by ICP-OES and relative humidity of raw and cooked mussels by thermogravimetry. Se level in microwaved samples was significantly decreased compared to raw and the other 2 cooked mussel samples. Zn concentration in raw samples was not significantly different compared to those in roasted samples. Fe level was insignificantly different between boiled and roasted samples and significantly lowers in microwaved samples. Ni, Pb, and Se levels were significantly higher in boiled samples, and Cd levels were insignificantly different reported to cooking method. The percentage of water loss during roasting was lower than the other 2 thermal preparation methods. Potassium concentrations in cooked mussels were higher compared to raw ones. Mineral concentrations were highest in roasted samples and heavy metal concentrations in boiled mussels.

  11. Analysis of CR1 Repeats in the Zebra Finch Genome

    Directory of Open Access Journals (Sweden)

    George E. Liu

    2013-06-01

    Full Text Available Most bird species have smaller genomes and fewer repeats than mammals. Chicken Repeat 1 (CR1 repeat is one of the most abundant families of repeats, ranging from ~133,000 to ~187,000 copies accounting for ~50 to ~80% of the interspersed repeats in the zebra finch and chicken genomes, respectively. CR1 repeats are believed to have arisen from the retrotransposition of a small number of master elements, which gave rise to multiple CR1 subfamilies in the chicken. In this study, we performed a global assessment of the divergence distributions, phylogenies, and consensus sequences of CR1 repeats in the zebra finch genome. We identified and validated 34 CR1 subfamilies and further analyzed the correlation between these subfamilies. We also discovered 4 novel lineage-specific CR1 subfamilies in the zebra finch when compared to the chicken genome. We built various evolutionary trees of these subfamilies and concluded that CR1 repeats may play an important role in reshaping the structure of bird genomes.

  12. Urinary androgen concentrations and social status in two species of free ranging zebra (Equus burchelli and E. grevyi).

    Science.gov (United States)

    Chaudhuri, M; Ginsberg, J R

    1990-01-01

    In both species of zebra, breeding males had higher urinary androgen concentrations (ng androgens/mg Cr) than did non-breeding bachelor males (30.0 +/- 5.0 (N = 9) versus 11.4 +/- 2.8, (N = 7) in the plains zebra; 19.0 +/- 2.2 (N = 17) versus 10.7 +/- 1.2 (N = 14) in the Grevy's zebra). In the more stable family structure of the plains zebra (single male non-territorial groups) variations in androgen concentrations could not be ascribed to any measured variable. In the Grevy's zebra, androgen values were significantly lower in samples taken from territorial (breeding) males which had temporarily abandoned their territories (N = 4) and the urinary androgen concentration for a male on his territory was negatively correlated with the time since females last visited the territory.

  13. Trophic interference by Salmo trutta on Aplochiton zebra and Aplochiton taeniatus in southern Patagonian lakes.

    Science.gov (United States)

    Elgueta, A; González, J; Ruzzante, D E; Walde, S J; Habit, E

    2013-02-01

    The length and mass ratio, diet and isotopic composition of Aplochiton zebra and Aplochiton taeniatus inhabiting a Salmo trutta-invaded and a S. trutta-free lake in southern Patagonia were compared. Results indicate that S. trutta exercises important trophic interference over A. zebra and A. taeniatus, causing changes in their dietary composition by reducing the consumption of winged Diptera through changes in feeding behaviours that involve jumping out of the water. This effect is significantly higher in A. zebra than in A. taeniatus a species that has a highly specialized diet. The dietary changes of A. zebra and A. taeniatus in sympatry with S. trutta lead to an impoverishment of their isotopic nitrogen signals (δ(15)N), suggesting a reduction of their trophic position. In the case of A. zebra, this translates into a significant decrease in its body condition factor. Such interference could lead to a population decline of this species and would explain the current distribution range decline and allopatry with S. trutta in fluvial systems. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  14. Standing sedation in captive zebra (Equus grevyi and Equus burchellii).

    Science.gov (United States)

    Hoyer, Mark; de Jong, Sara; Verstappen, Frank; Wolters, Marno

    2012-03-01

    Nine Grevy's zebras (Equus grevyi) and three Burchell's zebras (Equus burchellii) were immobilized in a standing position a total of 70 times for minor, nonpainful procedures over a 9-yr period. Standing sedation was successfully obtained with a combination of detomidine and butorphanol on 47 occasions (67.1%). Detomidine i.m. (median 0.10 mg/kg; range: 0.07-0.21) was administered by dart, followed 10 min later by butorphanol i.m. (median 0.13 mg/kg; range 0.04-0.24). The dosages were varied depending on the initial demeanor of the animal. On 23 occasions (32.9%), small amounts of etorphine (median 2.5 microg/kg; range 1.1-12.3 microg/kg) plus acepromazine (median 10 microg/kg; range 4.4-50 microg/kg) (as in Large Animal-Immobilon) had to be administered i.m. to gain sufficient sedation. In these latter cases, the animals were either excited or known for their aggressive character. The zebras were sufficiently immobilized for the length of most procedures (<45 min) without supplementation. At the end of the procedure, the animals were given atipamezole (2 mg per 1 mg detomidine used) and naltrexone (0.1 mg/kg) to reverse the sedative effects, irrespective of whether etorphine was used or not. Standing sedation, using the combination of the alpha-2 agonist detomidine and the partial agonist-antagonist opioid butorphanol (in some cases supplemented with etorphine + acepromazine), proved to be a very efficacious and safe method to be used in zebras under zoo conditions for short-lasting, nonpainful procedures.

  15. Acoustic fine structure may encode biologically relevant information for zebra finches.

    Science.gov (United States)

    Prior, Nora H; Smith, Edward; Lawson, Shelby; Ball, Gregory F; Dooling, Robert J

    2018-04-18

    The ability to discriminate changes in the fine structure of complex sounds is well developed in birds. However, the precise limit of this discrimination ability and how it is used in the context of natural communication remains unclear. Here we describe natural variability in acoustic fine structure of male and female zebra finch calls. Results from psychoacoustic experiments demonstrate that zebra finches are able to discriminate extremely small differences in fine structure, which are on the order of the variation in acoustic fine structure that is present in their vocal signals. Results from signal analysis methods also suggest that acoustic fine structure may carry information that distinguishes between biologically relevant categories including sex, call type and individual identity. Combined, our results are consistent with the hypothesis that zebra finches can encode biologically relevant information within the fine structure of their calls. This study provides a foundation for our understanding of how acoustic fine structure may be involved in animal communication.

  16. Forward osmosis membrane fouling and cleaning for wastewater reuse

    Directory of Open Access Journals (Sweden)

    Youngbeom Yu

    2017-06-01

    Full Text Available Membrane fouling properties and different physical cleaning methods for forward osmosis (FO and reverse osmosis (RO laboratory-scale filtration systems were investigated. The membrane fouling, with respect to flux reduction, was lower in FO than in RO when testing an activated sludge effluent. Cross-flow velocity, air-scouring, osmotic backwashing and effect of a spacer were compared to determine the most effective cleaning method for FO. After a long period of fouling with activated sludge, the flux was fully recovered in a short period of osmotic backwashing compared with cleaning by changing cross-flow velocity and air-scouring. In this study, the osmotic backwashing was found to be the most efficient way to clean the FO membrane. The amount of RNA recovered from FO membranes was about twice that for RO membranes; biofouling could be more significant in FO than in RO. However, the membrane fouling in FO was lower than that in RO. The spacer increased the flux in FO with activated sludge liquor suspended solids of 2,500 mg/L, and there were effects of spacer on performance of FO–MBR membrane fouling. However, further studies are required to determine how the spacer geometry influences on the performance of the FO membrane.

  17. Membrane filtration device for studying compression of fouling layers in membrane bioreactors.

    Directory of Open Access Journals (Sweden)

    Mads Koustrup Jørgensen

    Full Text Available A filtration devise was developed to assess compressibility of fouling layers in membrane bioreactors. The system consists of a flat sheet membrane with air scouring operated at constant transmembrane pressure to assess the influence of pressure on resistance of fouling layers. By fitting a mathematical model, three model parameters were obtained; a back transport parameter describing the kinetics of fouling layer formation, a specific fouling layer resistance, and a compressibility parameter. This stands out from other on-site filterability tests as model parameters to simulate filtration performance are obtained together with a characterization of compressibility. Tests on membrane bioreactor sludge showed high reproducibility. The methodology's ability to assess compressibility was tested by filtrations of sludges from membrane bioreactors and conventional activated sludge wastewater treatment plants from three different sites. These proved that membrane bioreactor sludge showed higher compressibility than conventional activated sludge. In addition, detailed information on the underlying mechanisms of the difference in fouling propensity were obtained, as conventional activated sludge showed slower fouling formation, lower specific resistance and lower compressibility of fouling layers, which is explained by a higher degree of flocculation.

  18. Hydraulic Evaluation of Discharge Over Submerged Rock Wing Dams on the Upper Mississippi River

    National Research Council Canada - National Science Library

    Hendrickson, Jon

    1999-01-01

    .... This analysis was part of a study, done through the Corps of Engineers' Land Management System, to determine the impacts of zebra mussels on water quality and ecological conditions in the Upper Mississippi River (UMR). Wing dams...

  19. Magnetic resonance imaging of live freshwater mussels (Unionidae)

    Science.gov (United States)

    Michael, Holliman F.; Davis, Denise; Bogan, Arthur E.; Kwak, Thomas J.; Cope, W. Gregory; Levine, Jay F.

    2008-01-01

    We examined the soft tissues of live freshwater mussels, Eastern elliptio Elliptio complanata, via magnetic resonance imaging (MRI), acquiring data with a widely available human whole-body MRI system. Anatomical features depicted in the profile images included the foot, stomach, intestine, anterior and posterior adductor muscles, and pericardial cavity. Noteworthy observations on soft tissue morphology included a concentration of lipids at the most posterior aspect of the foot, the presence of hemolymph-filled fissures in the posterior adductor muscle, the presence of a relatively large hemolymph-filled sinus adjacent to the posterior adductor muscle (at the ventral-anterior aspect), and segmentation of the intestine (a diagnostic description not reported previously in Unionidae). Relatively little is known about the basic biology and ecological physiology of freshwater mussels. Traditional approaches for studying anatomy and tissue processes, and for measuring sub-lethal physiological stress, are destructive or invasive. Our study, the first to evaluate freshwater mussel soft tissues by MRI, clarifies the body plan of unionid mussels and demonstrates the efficacy of this technology for in vivoevaluation of the structure, function, and integrity of mussel soft tissues.

  20. Microbial community structure characteristics associated membrane fouling in A/O-MBR system.

    Science.gov (United States)

    Gao, Da-Wen; Wen, Zhi-Dan; Li, Bao; Liang, Hong

    2014-02-01

    The study demonstrated the potential relationship between microbial community structure and membrane fouling in an anoxic-oxic membrane bioreactor (A/O-MBR). The results showed that the microbial community structure in biocake was different with aerobic mixture, and the dominant populations were out of sync during the fouling process. Based on microbial community structure and metabolites analysis, the results showed that the succession of microbial community might be the leading factor to the variation of metabolites, and it might be the primary cause of membrane fouling. The rise of Shannon diversity index (H) of the microbial community in A/O-MBR went with the gradually serious membrane fouling. Pareto-Lorenz curve was used to describe the evenness of microbial distribution in A/O-MBR, and the result indicated when community evenness was low, the membrane fouling took place smoothly or slightly, otherwise, high evenness of microbial community would lead to more seriously membrane fouling. Copyright © 2013 Elsevier Ltd. All rights reserved.