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J. Ellen Marsden - One of the best experts on this subject based on the ideXlab platform.
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Recruitment of Lake trout in Lake Champlain
Journal of Great Lakes Research, 2018Co-Authors: J. Ellen Marsden, Carrie L. Kozel, Brian D. ChipmanAbstract:Abstract Lake trout were extirpated from Lake Champlain by 1900, and are currently the focus of intensive efforts to restore a self-sustaining population. Stocking of yearling Lake trout since 1972 has re-established adult populations, spawning occurs at multiple sites Lake-wide, and fry production at several sites is very high. However, little to no recruitment past age-0 has occurred, as evidenced by the absence of adults without hatchery fin clips in fall assessments; no regular sampling for juveniles is conducted. We began focused sampling for juvenile Lake trout in fall, 2015, in the Main Lake using bottom trawling, and expanded sampling to sites in the north and south of the Lake in 2016. In 2015 we collected 303 Lake trout
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Influence of Environmental Factors on Zebra Mussel Population Expansion in Lake Champlain, 1994-2010
2013Co-Authors: J. Ellen Marsden, Pete Stangel, Angela D. ShambaughAbstract:The spread of zebra mussels is facilitated by currents and human traf�耀c and may be limited by temperature, calcium availability, and productivity. Lake Champlain is an interesting system for examining factors that affect spread of zebra mussels, as the Lake has a complex structure consisting of bays separated by islands and causeways, water �耀ows from south to north, temperature and calcium concentrations decrease from south to north, and productivity is highest in southern areas of the Lake and in regions of the Northeast Arm. Zebra mussels were �耀rst discovered in Lake Champlain in 1993 and spread to all regions of the Lake by 1996. Monitoring was conducted at 24 stations Lake-wide between 1994 and
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Lake Whitefish Diet, Condition, and Energy Density in Lake Champlain and the Lower Four Great Lakes following Dreissenid Invasions
Transactions of the American Fisheries Society, 2013Co-Authors: Seth J. Herbst, J. Ellen Marsden, Brian F. LantryAbstract:Abstract Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining e...
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Lake Champlain 2010: A summary of recent research and monitoring initiatives
Journal of Great Lakes Research, 2012Co-Authors: Douglas E. Facey, Timothy B. Mihuc, J. Ellen Marsden, Eric A. HoweAbstract:Abstract Lake Champlain shares a geological history with the Great Lakes and, as part of the St. Lawrence drainage, also shares biological and ecological similarities. The complex bathymetry and extensive shoreline provide a variety of lacustrine habitats, from deep oligotrophic areas to shallow bays that are highly eutrophic. The large basin:Lake ratio (19:1) makes Lake Champlain vulnerable to impacts associated with land use, and in some parts of the Lake these impacts are further exacerbated by limited water exchange among Lake segments due to both natural and anthropogenic barriers. Research in Lake Champlain and the surrounding basin has expanded considerably since the 1970s, with a particularly dramatic increase since the early 1990s. This special issue of the Journal of Great Lakes Research brings together 16 reports from recent research and monitoring efforts in Lake Champlain. The papers cover a variety of topics but primarily focus on Lake hydrodynamics; historical and recent chemical changes in the Lake; phosphorus loading; recent changes in populations of phytoplankton, zooplankton, and fishes; impacts of invasive species; recreational use; and the challenges of management decision-making in a Lake that falls within the legal jurisdictions of two U.S. states, one Canadian province, two national governments, and the International Joint Commission. The papers provide not only evaluations of progress on some critical management issues but also valuable reference points for future research.
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A life cycle approach to modeling sea lamprey population dynamics in the Lake Champlain basin to evaluate alternative control strategies
Journal of Great Lakes Research, 2012Co-Authors: Eric A. Howe, J. Ellen Marsden, Therese M. Donovan, Roland H. LambersonAbstract:Sea lamprey (Petromyzon marinus) is a nuisance species in the Laurentian Great Lakes and Lake Champlain that has devastated native fish populations and hampered sport fisheries development. We developed a modified stage-based life history matrix for sea lamprey to analyze the effects of various management efforts to suppress sea lamprey population growth in Lake Champlain. These efforts targeted different life stages of the sea lamprey life cycle. A beta distribution was used to distribute stochastic larval populations among twenty sea lamprey-bearing tributaries and five deltas to Lake Champlain, from which sea lamprey that survive through larval metamorphosis were then pooled into a Lake-wide parasitic-phase population. Parasitic-phase survival to the spawning stage was evaluated based on proximity to the natal tributary and on the size of the resident larval population in each tributary. Potential control strategies were modeled at egg to emergence, larval, and spawning stages to reduce vital rates at each stage, with the goal of suppressing parasitic-phase production. Simulations indicate that control of the larval stage was essential to achieving this goal, and with supplemental effort to reduce the vital rates at early life stages and at the spawning stage, the parasitic-phase population can be further suppressed. Sensitivity simulations indicate that the life history model was sensitive to egg deposition rate, abundance of parasitic-phase sea lamprey from unknown, uncontrolled sources, and the method in which parasitic-phase sea lamprey select tributaries for spawning. Results from this model can guide management agencies to optimize future management programs.
Timothy B. Mihuc - One of the best experts on this subject based on the ideXlab platform.
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Lessons from Bioinvasion of Lake Champlain, U.S.A.
Ecological Informatics, 2017Co-Authors: Timothy B. Mihuc, Friedrich RecknagelAbstract:Freshwater Lakes provide ideal habitat for invasive species, such as the zebra mussel, which can weaken Lake ecological integrity by altering food web structure and dynamics. This case study utilized 23 years Lake Champlain data to examine relationships among water quality, invasive species, native mysids (Mysis diluviana) and the zooplankton community. Canonical correspondence analysis (CCA) was employed to ordinate and qualitatively assess long-term patterns across the datasets, and the hybrid evolutionary algorithm (HEA) revealed quantitative relationships and thresholds. Results from both methods are complementary and suggest that: (1) zebra mussels directly affect rotifer densities by preying on slow moving rotifers, and (2) zebra mussels indirectly affect cladocerans, copepods and mysids by both preying on rotifers and grazing on phytoplankton. The direct and indirect effects of zebra mussels on the zooplankton community as well as on mysids adversely affect the ecological integrity of Lake Champlain. Data ordination by CCA and inferential modelling by HEA proved useful for elucidating long-term food web patterns in the complex Lake Champlain ecosystem.
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Mysis zooplanktivory in Lake Champlain: A bioenergetics analysis
Journal of Great Lakes Research, 2015Co-Authors: Allison R. Hrycik, Paul W. Simonin, Lars G. Rudstam, Donna L. Parrish, Bernard Pientka, Timothy B. MihucAbstract:Abstract Mysid shrimp are important both as predators on zooplankton and as prey for a variety of fish species across most of the Laurentian Great Lakes. In Lake Champlain, where little is known about mysids, this may also be true. We evaluated the role of Mysis diluviana as a planktivore in Lake Champlain using hydroacoustics, gut content analysis, stable isotopes, cohort analysis, and bioenergetics models to estimate Mysis density, diets, growth rates, and prey consumption rates. Density of Mysis in the water column of the deeper Main Lake was lower in July–August of 2008–2011 (38, 38, 21, and 74 Mysis /m 2 , respectively) than historical values from the 1970s. Mysis selectively foraged for cladocerans, but also consumed cyclopoid and calanoid copepods in 2011. Stable isotope data suggest a mostly carnivorous diet, although agreement between isotope mixing models and observed diets varied. Cohort analyses revealed growth rates ranging from 2.7 mm/month in late spring to 1.3 mm/month in late summer. In contrast to the offshore areas of Lake Ontario and Lake Huron, zooplankton consumption by the Mysis population was low relative to zooplankton density and production indicating that Mysis are not currently a major zooplanktivore in Lake Champlain.
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Ten-fold decline in Mysis diluviana in Lake Champlain between 1975 and 2012
Journal of Great Lakes Research, 2015Co-Authors: Suzanne C. Ball, Timothy B. Mihuc, Luke Myers, Jason D. StockwellAbstract:Mysis diluviana is an important mid-trophic level omnivore in many Lakes, but studies of Mysis in Lake Champlain are rare. We used an unpublished 1975 study as a baseline to test for changes in contemporary Mysis populations in Lake Champlain. Invasive zebra mussels (Dreissena polymorpha) and alewives (Alosa pseudoharengus) were first reported in 1993 and 2003, respectively. Based on the negative relationships of these two species with Mysis and Mysis prey in the Great Lakes, we hypothesized a decline in Mysis in Lake Champlain since 1975 and tested this by repeating the 1975 study in 2012. We found a nearly ten-fold decrease in mean density (± SD) between 1975 (712 ± 373 individuals/m2) and 2012 (82 ± 48 individuals/m2; p = 0.002). Despite the decline, Mysis growth rates appeared similar between the two studies, although fecundity significantly increased by 3 embryos/female in 2012 (p = 0.002). Mysis vertical distribution appeared similar in both years, while the horizontal distribution appeared limited to deeper bathymetric strata in 2012 compared to 1975. Data from a long-term monitoring program from 1992 to 2008 indicate the decline occurred abruptly in the mid-1990s, which coincided with zebra mussel establishment although a direct link between the two is not evident. Alewife did not invade Lake Champlain until 2003 and can be ruled out as a contributing factor to the decline. We hypothesize that the combination of predation by alewife and smelt and shifts in the planktonic food web may prevent Mysis from recovering to pre-1995 densities.
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Lake Champlain 2010: A summary of recent research and monitoring initiatives
Journal of Great Lakes Research, 2012Co-Authors: Douglas E. Facey, Timothy B. Mihuc, J. Ellen Marsden, Eric A. HoweAbstract:Abstract Lake Champlain shares a geological history with the Great Lakes and, as part of the St. Lawrence drainage, also shares biological and ecological similarities. The complex bathymetry and extensive shoreline provide a variety of lacustrine habitats, from deep oligotrophic areas to shallow bays that are highly eutrophic. The large basin:Lake ratio (19:1) makes Lake Champlain vulnerable to impacts associated with land use, and in some parts of the Lake these impacts are further exacerbated by limited water exchange among Lake segments due to both natural and anthropogenic barriers. Research in Lake Champlain and the surrounding basin has expanded considerably since the 1970s, with a particularly dramatic increase since the early 1990s. This special issue of the Journal of Great Lakes Research brings together 16 reports from recent research and monitoring efforts in Lake Champlain. The papers cover a variety of topics but primarily focus on Lake hydrodynamics; historical and recent chemical changes in the Lake; phosphorus loading; recent changes in populations of phytoplankton, zooplankton, and fishes; impacts of invasive species; recreational use; and the challenges of management decision-making in a Lake that falls within the legal jurisdictions of two U.S. states, one Canadian province, two national governments, and the International Joint Commission. The papers provide not only evaluations of progress on some critical management issues but also valuable reference points for future research.
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long term patterns in Lake Champlain s zooplankton 1992 2010
Journal of Great Lakes Research, 2012Co-Authors: Timothy B. Mihuc, Fred Dunlap, Casey Binggeli, Luke Myers, Carrianne Pershyn, Amanda Groves, Allison WaringAbstract:Abstract We examined patterns in Lake Champlain zooplankton abundance from 1992 to 2010 using summer data from five study sites. Rotifer abundance (#/m 3 ) for many common taxa such as Polyarthra , Kellicottia , and Keratella declined Lakewide in the mid-1990s which coincided with the invasion of zebra mussels ( Dreissena polymorpha ) into Lake Champlain. The only rotifer to increase in density following zebra mussel invasion was Conochilus which is a colonial species. Long-term shifts in copepod and cladoceran community composition can be attributed to the arrival of another invasive species in 2004–2005, the alewife ( Alosa pseudoharengus ). Our results support previous findings that alewife predation can impact larger bodied zooplankton within temperate Lake systems. Following alewife invasion into Lake Champlain, body length of Leptodiaptomus and Daphnia retrocurva decreased to a size at or below known alewife feeding preferences. In addition, smaller bodied copepods (primarily Diacyclops thomasi ) have increased in abundance since alewife invasion while juvenile copepods have declined. Our results suggest that post-alewife zooplankton patterns are most likely due to alewife size-selective feeding strategies. Observed long-term changes in zooplankton community structure have potential implications for the Lake's food web dynamics, particularly recent declines in large bodied zooplankton which may release smaller plankton from top-down control.
Sorrentino, Madelyn Gene - One of the best experts on this subject based on the ideXlab platform.
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Spatio-temporal variation in total lipid content of juvenile Lake trout (Salvelinus namaycush) in Lake Champlain
ScholarWorks @ UVM, 2019Co-Authors: Sorrentino, Madelyn GeneAbstract:After more than 40 years of stocking, Lake trout (Salvelinus namaycush) in Lake Champlain has started to exhibit strong, natural recruitment. However, the spatial distribution of wild Lake trout shows variation in abundance and Fulton’s condition factor among regions of Lake Champlain. These differences suggest the prey base, or foraging success, may vary geographically within the Lake. One metric that may indicate differences in resources across regions is lipid content, which reflects the quality of available food. We will quantify the lipid content of Lake trout across spatial (Lake regions) and temporal (seasonal) scales. Based on observed differences in condition, we expect that lipid content will vary in Lake trout (1) spatially across regions of the Lake, and be highest in the Main Lake, and (2) among seasons, where lipid content increases from spring to autumn. The availability of quality food sources, as indicated by lipid content, could influence Lake trout production and ultimately support the successful recruitment of this ecologically and recreationally valuable species through bottom-up processes
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Spatio-temporal variation in total lipid content of stocked and wild juvenile Lake trout (Salvelinus namaycush) in Lake Champlain
ScholarWorks @ UVM, 2019Co-Authors: Sorrentino, Madelyn GeneAbstract:After more than 40 years of stocking, Lake trout (Salvelinus namaycush) in Lake Champlain have started to exhibit strong, natural recruitment which suggests a change in limiting factors such as the prey base or overwinter survival. The distribution of juvenile wild Lake trout shows variation in abundance and condition factor among regions of Lake Champlain. These differences suggest the prey base, or foraging success, may vary geographically within the Lake. Stocked and wild Lake trout may differ in their ability to utilize resources and in overwinter survival. One metric that may indicate differences in resources across regions is lipid content, which reflects the quality of available food and acts as an important energy reserve for overwinter survival. We quantified total lipid content of stocked and wild juvenile Lake trout across spatial (Lake regions) and temporal (seasonal) scales. No spatial differences in lipid content were apparent. Wild fish were significantly greater in lipid content than stocked fish. Seasonally, stocked fish showed a drop in lipid content from pre-winter levels to the following spring, and lipids continued to drop through autumn. Wild fish showed a cyclical summer increase in lipids following replenishment from winter depletion, which plateaued by autumn. Results suggest that hatchery conditions cause stocked juvenile Lake trout to be less competitive in the Lake Champlain environment than wild juveniles, evidenced by their lower lipid content and seasonal depletion. Hatchery practices could be modified to produce more competitive juvenile Lake trout and support the goal of restoring a self-sustaining population
Lucas Edward Bernacki - One of the best experts on this subject based on the ideXlab platform.
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The Molecular Evolution of Non-Coding DNA and Population Ecology of the Spiny Softshell Turtle (Apalone spinifera) in Lake Champlain
2014Co-Authors: Lucas Edward BernackiAbstract:Spiny softshell turtles (Apalone spinifera) occur at the northwest limit of their range in Lake Champlain. This species, although widespread across North America, is listed as threatened in Vermont due to habitat destruction and disturbances of anthropogenic origin. The population of spiny softshell turtles in Lake Champlain is isolated from other North American populations and is considered as an independent management unit. Efforts to obtain information on the biology of spiny softshell turtles in Lake Champlain precede 1936 with conservation measures being initiated in 1987. Methods of studying spiny softshell turtles in Lake Champlain have included direct observation, mark-recapture, nest beach monitoring, winter diving, and radio telemetry. Each of these approaches has provided some information to the sum of what is known about A. spinifera in Lake Champlain. For example major nesting beaches, hibernacula, and home range size have been determined. Currently spiny softshell turtles primarily inhabit two areas within Lake Champlain, Missisquoi Bay and the mouth of the Lamoille River. However, the population structure and gene flow between spiny softshell turtles inhabiting the Lamoille and Missisquoi regions remained unknown. A GIS model was created and tested in order to identify additional nesting beaches used by spiny softshell turtles along the Vermont shores of Lake Champlain. Although some additional small potential nesting beaches were found, no additional major nesting sites were found. The GIS model identified the mouth of the Winooski River (the site of a historical population) as potentially suitable nesting habitat; however, no evidence of spiny softshell turtle nesting was found at this site. A series of methods developed for collecting molecular and population genetic data about spiny softshell turtles in Lake Champlain are described, including techniques for DNA extraction of various tissue types and the design of new primers for PCR amplification and sequencing of the mitochondrial control region (mtD-loop). Techniques for circumventing problems associated with DNA sequence alignment in regions of a variable numbers of tandem repeats (VNTRs) and the presence of heteroplasmy within some individuals are also described. The mtD-loop was found to be a suitable marker to assess the genetic structure of the Lake Champlain population of spiny softshell turtles. No significant genetic substructuring was found (FST=0.082, p=0.223) and an indirect estimate of the migration rate between Lamoille and Missisquoi regions of Lake Champlain was high (Nm>5.576). In addition to consideration of A. spinifera in Lake Champlain, the mtD-loop was modeled across 46 species in 14 families of extant turtles. The primary structure was obtained from DNA sequences accessed from GenBank and secondary structures of the mtD-loop were inferred, (from thermal stabilities) using the program Mfold, for each superfamiliy of turtles. Both primary and secondary structures were found to be highly variable across the order of turtles; however, the inclusion of an AT-rich fold (secondary structure) near the 3’ terminus of the mtD-loop was common across all turtle families considered. The Cryptodira showed conservation in the primary structure at regular conserved sequence blocks (CSBs), but the Pluerodira displayed little conservation in the primary structure of the mtD-loop. Overall, greater conservation in secondary structure than primary structure was observed in turtle mtD-loop. The AT-rich secondary structural element near the 3’ terminus of the mtD-loop may be conserved across turtles due to it serving a functional role during mtDNA transcription.
Martin Ouellet - One of the best experts on this subject based on the ideXlab platform.
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Traumatic Injuries in Eastern Spiny Softshell Turtles (Apalone spinifera) Due to Recreational Activities in the Northern Lake Champlain Basin
Chelonian Conservation and Biology, 2007Co-Authors: Patrick Galois, Martin OuelletAbstract:ABSTRACT We report several boat propeller- and fishing-related injuries sustained by eastern spiny softshell turtles (Apalone spinifera) from the northern Lake Champlain basin of Quebec and Vermont. These incidents may have negative impacts at the population level when added to habitat alterations and other mortality factors challenging this threatened and isolated northern population.
