Publications by authors named "Travis O Brenden"

Integrated Pest Management (IPM) provides a powerful framework for addressing threats to human well-being caused by nuisance species including invasives. We examined the hypothesis that adaptive management could erode barriers to IPM implementation by developing a decision-analytic adaptive management framework for invasive sea lamprey (Petromyzon marinus) IPM in the Laurentian Great Lakes of North America. The framework addressed objectives associated with coordinating multiple sea lamprey control actions at the regional scale and objectives associated with internal validity of control actions.

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Lake whitefish (Coregonus clupeaformis; LWF) is an economically and ecologically valuable native species to the Great Lakes, but recent declines in their recruitment have generated significant concern about their future viability. Although studies have sought to identify factors contributing to declining recruitment, the potential role(s) of infectious diseases has not been thoroughly investigated. In 2018 and 2019, adult LWF were collected from Lakes Superior, Michigan, and Huron for clinical examination and bacteriological analyses.

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Article Synopsis
  • Flavobacterium psychrophilum is the main cause of bacterial coldwater disease (BCWD), which leads to major economic losses in farmed Rainbow Trout worldwide.
  • Over the past decade, researchers have identified over 30 clonal complexes (CCs) of this bacteria, with CC-ST10 being the most studied, while the virulence of other complexes, such as CC-ST191, has not been thoroughly explored.
  • Experimental infections with strains from both CC-ST10 and CC-ST191 on Rainbow Trout showed high mortality rates, indicating that both clonal complexes are highly virulent and warrant further research for BCWD prevention and control.
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Flavobacterium psychrophilum causes bacterial coldwater disease (BCWD) in salmonids, resulting in significant losses worldwide. Several serotyping and genetic studies of F. psychrophilum have suggested some geno-/serotypes may be either host-specific or generalistic in nature; however, this association has not been adequately explored in vivo using more natural exposure routes.

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Effective water quality management depends on enactment of appropriately designed monitoring programs to reveal current and forecasted conditions. Because water quality conditions are influenced by numerous factors, commonly measured attributes such as total phosphorus (TP) can be highly temporally varying. For highly varying processes, monitoring programs should be long-term and periodic quantitative analyses are needed so that temporal trends can be distinguished from stochastic variation, which can yield insights into potential modifications to the program.

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Background: Mortality episodes have affected young-of-year smallmouth bass (Micropterus dolomieu) in several river systems in Pennsylvania since 2005. A series of laboratory experiments were performed to determine the potential role of largemouth bass virus (Ranavirus, Iridoviridae) in causing these events.

Results: Juvenile smallmouth bass experimentally infected with the largemouth bass virus exhibited internal and external clinical signs and mortality consistent with those observed during die-offs.

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Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, threatens salmonid populations throughout the Northern hemisphere. Many fishery regulatory authorities require ongoing disease monitoring in hatcheries and spawning runs prior to gamete collection to prevent BKD outbreaks and spread. According to diagnostic protocols of the American Fisheries Society-Fish Health Section, monitoring for R.

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Sex determination mechanisms in fishes lie along a genetic-environmental continuum and thereby offer opportunities to understand how physiology and environment interact to determine sex. Mechanisms and ecological consequences of sex determination in fishes are primarily garnered from teleosts, with little investigation into basal fishes. We tagged and released larval sea lamprey () into unproductive lake and productive stream environments.

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Despite the prevalence of damming as a global disturbance to river habitats, detailed reach-based assessments of the ecological effects of dams are lacking, particularly across large spatial extents. Using data from nearly 50,000 large dams, we assessed stream network fragmentation and flow alteration by large dams for streams of the conterminous USA. We developed 21 dam metrics characterizing a diversity of dam influences operating at both localized (e.

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A DNA vaccine containing the glycoprotein (G) gene of the North American viral hemorrhagic septicemia virus (VHSV) genotype IVb was developed to evaluate the immune response of fish following vaccination and evaluate its efficacy in protecting a susceptible species, the Muskellunge Esox masquinongy, against VHSV-IVb challenge. Seven weeks (539 degree-days) following vaccination with 10 μg of either pVHSivb-G or a control plasmid, Muskellunge were challenged by immersion with 10 plaque-forming units (pfu)/mL of VHSV-IVb. Fish vaccinated with pVHSivb-G had a relative percent survival (RPS) of 45%.

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Background: The viral hemorrhagic septicemia virus (VHSV) is one of the most serious fish pathogens. In 2003, a novel sublineage (genotype IVb) of this deadly virus emerged in the Great Lakes basin causing serious fish kills. We have previously demonstrated that a DNA plasmid (pcDNA), containing a cytomegalovirus (CMV) promoter and the viral hemorrhagic septicemia virus (VHSV) genotype IVb glycoprotein (G) gene insert (designated pVHSivb-G) confers moderate protection in muskellunge (Esox masquinongy), a highly susceptible species upon challenge.

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Viral hemorrhagic septicemia virus genotype IVb (VHSV-IVb) is presently found throughout the Laurentian Great Lakes region of North America. We recently developed a DNA vaccine preparation containing the VHSV-IVb () gene with a cytomegalovirus (CMV) promoter that proved highly efficacious in protecting muskellunge () and three salmonid species. This study was conducted to determine whether cohabitation of VHSV-IVb immunized fishes could confer protection to non-vaccinated (i.

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Bacterial communities play important roles in the biological functioning of crustaceans, yet little is known about their diversity, structure, and dynamics. This study was conducted to investigate the bacterial communities associated with the benthic amphipod Diporeia, an important component in the Great Lakes foodweb that has been declining over the past 3 decades. In this study, the combination of 16S rRNA gene sequencing and terminal restriction fragment length polymorphism revealed a total of 175 and 138 terminal restriction fragments (T-RFs) in Diporeia samples following treatment with the endonucleases HhaI and MspI, respectively.

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Since the 1990s, populations of the benthic amphipod Diporeia spp. (Diporeia) have sharply declined across much of the Laurentian Great Lakes. This study was undertaken to identify contemporary and historical community composition, structure, and dynamics of parasites infecting Diporeia collected from nine sites in the southern basin of Lake Michigan, where declines of the amphipod have been well documented over the past 20years.

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A competitive enzyme-linked immunosorbent assay (cELISA) was developed for the detection of antibodies to viral hemorrhagic septicemia virus genotype IVb (VHSV-IVb) in fish sera. Assay conditions were standardized using known negative and positive muskellunge Esox masquinongy. A positive-negative threshold of 14.

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Background: Buruli ulcer (BU) disease, caused by infection with the environmental mycobacterium M. ulcerans, is an emerging infectious disease in many tropical and sub-tropical countries. Although vectors and modes of transmission remain unknown, it is hypothesized that the transmission of BU disease is associated with human activities in or around aquatic environments, and that characteristics of the landscape (e.

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The identification of disturbance thresholds is important for many aspects of aquatic resource management, including the establishment of regulatory criteria and the identification of stream reference conditions. A number of quantitative or model-based approaches can be used to identify disturbance thresholds, including nonparametric deviance reduction (NDR), piecewise regression (PR), Bayesian changepoint (BCP), quantile piecewise constant (QPC), and quantile piecewise linear (QPL) approaches. These methods differ in their assumptions regarding the nature of the disturbance-response variable relationship, which can make selecting among the approaches difficult for those unfamiliar with the methods.

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