The Experts below are selected from a list of 333 Experts worldwide ranked by ideXlab platform
Norman D. Yan - One of the best experts on this subject based on the ideXlab platform.
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a review of the effects of Bythotrephes longimanus and calcium decline on zooplankton communities can interactive effects be predicted
Environmental Reviews, 2015Co-Authors: Shakira S E Azan, Shelley E Arnott, Norman D. YanAbstract:Anthropogenic stressors including acid deposition, invasive species, and calcium (Ca) decline have produced widespread damage to Canadian Shield lakes, especially to their zooplankton communities. Here, we review current knowledge on the individual effects on zooplankton by the non-indigenous predator Bythotrephes longimanus and Ca decline; we identify knowledge gaps in this literature and examine the likely interactive impacts of Bythotrephes invasions and Ca decline on zooplankton. The negative impacts of Bythotrephes longimanus on zooplankton communities are well known, whereas current understanding of the effects of declining Ca on zooplankton is restricted to Daphnia spp.; hence, there is a large knowledge gap on how declining Ca may affect zooplankton communities in general. The co-occurring impacts of Bythotrephes and declining Ca have rarely been studied at the species level, and we expect daphniids, particularly Daphnia retrocurva and Daphnia pulicaria, to be the most sensitive to both stressors....
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eicosapentaenoic acid limitation decreases weight and fecundity of the invading predator Bythotrephes longimanus
Journal of Plankton Research, 2014Co-Authors: Natalie Kim, Michael T Arts, Norman D. YanAbstract:Bythotrephes longimanus is an invasive predatory cladoceran that is negatively impacting North American zooplankton in the Laurentian Great Lakes and on the Canadian Shield. Concurrently, algal community composition, which affects zooplankton food quality, is changing in many lakes of the Canadian Shield. The n-3 fatty acid eicosapentaenoic acid (EPA) is highly retained in Bythotrephes, but the effects of EPA limitation on Bythotrephes’ population dynamics are unknown. To test the hypothesis that EPA limitation results in decreased weight and fecundity of Bythotrephes, the green alga Scenedesmus obliquus was cultured in the laboratory, split into EPA-enriched lines and un-enriched controls, then fed to Daphnia ambigua, which were in turn offered to juvenile Bythotrephes. Bythotrephes consuming EPA-enriched daphniids were heavier and had larger clutch sizes than those consuming control daphniids. Both diets supported ontogenesis, but not brood release, of Bythotrephes. To understand why laboratory-reared Bythotrephes did not release broods, we compared their fatty acid profiles with those of field-collected specimens, and found that they were EPA impoverished compared with field-collected conspecifics. Our results suggest that EPA availability influences Bythotrephes population dynamics, establishment success and impacts in nature.
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food limitation impacts life history of the predatory cladoceran Bythotrephes longimanus an invader to north america
Hydrobiologia, 2013Co-Authors: Natalie Kim, Norman D. YanAbstract:North American invasions of the predatory cladoceran Bythotrephes longimanus have resulted in declines in native zooplankton abundance, species richness, and diversity. In the field, population maxima of Bythotrephes are positively correlated to those of their zooplankton prey. To test the hypothesis that increased prey availability enhances Bythotrephes fitness, we reared Bythotrephes in the laboratory on three mixed-species prey densities (equivalent to 15, 30, and 45 prey organisms day−1; designated “low,” “medium,” and “high” food treatments, respectively) over 22 days at 21°C. Bythotrephes consumed the daily equivalent of 9, 14, and 22 prey organisms at the low, medium, and high food densities. Smaller, slower prey were most often selected. Indeed, with increasing prey density, Bythotrephes’ predation rates increased, resulting in significantly higher population growth rates, net reproductive rates, growth, and first brood clutch and offspring sizes; significantly faster generation times; and shorter maximum life spans. We propose that the positive relationship between Bythotrephes population maxima and prey seen in the field is largely due to increased predation rates by Bythotrephes when prey abundance is high and the fitness benefits that ensue. Our findings may be useful for Bythotrephes risk and impact assessments.
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dynamics of the invasive spiny water flea Bythotrephes longimanus in lake simcoe ontario canada
Inland Waters, 2013Co-Authors: Noreen E Kelly, Joelle D Young, Jennifer G Winter, Norman D. YanAbstract:The invasion of the nonindigenous zooplankter Bythotrephes longimanus in Lake Simcoe has the potential to impact overall ecosystem functioning, yet there is currently no information regarding the status and dynamics of its population. We used a combination of uni- and multivariate analyses to examine variation in Bythotrephes interannual and seasonal abundance, and life-history characteristics in Lake Simcoe from 1999 to 2007, and we explored the biotic (predators, prey) and/or abiotic (water quality, temperature) factors that may have regulated its population over this period. The mean annual abundance of Bythotrephes varied by an order of magnitude over the period of study and was significantly associated with epilimnetic temperature and prey and predator abundance. Bythotrephes typically appeared in early summer and had 2 seasonal abundance peaks, which varied in magnitude and timing within and among years. August and September Secchi depth and total phosphorus concentration predicted groups of years with similar Bythotrephes phenologies, lending further support to the role of water clarity as a significant component of this visual predator’s habitat in its invaded range. Bythotrephes body size and reproductive patterns also varied seasonally, possibly reflecting the seasonal availability of cladoceran prey, predation pressure from planktivorous fish, or adaptations to avoid unfavourable conditions. Overall, a complex interaction of fish predation, food availability, temperature, and water clarity controlled the dynamics of Bythotrephes in Lake Simcoe. Changes to the Lake Simcoe ecosystem due to Bythotrephes invasion may have important consequences for the ecosystem services provided by the lake and merit further investigation.
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shifting invertebrate zooplanktivores watershed level replacement of the native leptodora by the non indigenous Bythotrephes in canadian shield lakes
Biological Invasions, 2011Co-Authors: Erika Weisz, Norman D. YanAbstract:The abundance of the native, pelagic macroinvertebrate predator, Leptodora kindtii, is negatively correlated with the abundance of a new invasive competitor, Bythotrephes longimanus, in a small number of Canadian Shield lakes. However, we do not yet know if Bythotrephes is replacing Leptodora on a regional scale. We determined the distribution of both species in 166 lakes in the District of Muskoka, south-central Ontario, Canada—the watershed with the longest history and largest prevalence of Bythotrephes invasions in North America. The frequency of occurrence of Leptodora was substantially reduced (twofold) in the presence of Bythotrephes. We argue that Bythotrephes is responsible for this dramatic reduction in the frequency of occurrence of Leptodora. Lakes in which both species co-occurred could not be distinguished from invaded lakes without Leptodora, suggesting a pattern of species replacement at a watershed level. We believe this is the first account of the widespread replacement of a native, pelagic macroinvertebrate predator by Bythotrephes in North America, and it does not bode well for Leptodora given the rapid, ongoing spread of Bythotrephes.
Meghan E. Brown - One of the best experts on this subject based on the ideXlab platform.
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colonization dynamics of the invasive predatory cladoceran Bythotrephes longimanus inferred from sediment records
Limnology and Oceanography, 2017Co-Authors: Donn K Branstrator, Meghan E. Brown, Ashley E Beranek, Leif K Hembre, Daniel R EngstromAbstract:Despite the central role of colonization to invasion biology, little is known about the early dynamics of founder populations because this time period is often unobserved and short-lived. This study documents with high resolution the early population ecology of an invading freshwater zooplankton, Bythotrephes longimanus (Cladocera : Cercopagidae), by measuring accumulation rates of its caudal spine in sediments. Using dated (210Pb and 137Cs) sediment cores from four spatially distinct sites in Island Lake Reservoir (Minnesota, USA), we describe its first presence, early distribution, growth trajectory, and early impacts on prey. The sediment record shows that B. longimanus first appeared and was widely distributed in the lake in 1982 (± 2 yr, standard deviation), 8 yr before its first detection in the water, making it one of the earliest documented invasions in North America and suggesting that ecosystems may serve as dispersal hubs for years prior to detection. Logistic growth models describing spine accumulation rates show that B. longimanus required about two decades to achieve an annual equilibrium (K). Prolonged buildup to K may owe to several factors, including accumulation of a sufficiently large bank of resting eggs, the obligate overwintering life stage. Early exponential growth was incongruent with the presence of a lag phase. Post invasion, Daphnia mendotae became proportionally the most abundant daphniid in the lake, but the timing of the switch in prey species composition coincided more with the proliferation of B. longimanus density and its attainment of K than with its arrival to the lake.
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effects of chemical and physical conditions on hatching success of Bythotrephes longimanus resting eggs
Limnology and Oceanography, 2013Co-Authors: Donn K Branstrator, Meghan E. Brown, Lyle J Shannon, Marte T KitsonAbstract:Dormant eggs of zooplankton are considered to be tolerant of harsh environmental conditions, yet lethal thresholds of exposure have rarely been determined. We describe 3 yr of dose–response experiments that evaluate hatching success of the resting egg of Bythotrephes longimanus (Cladocera: Cercopagidae) in response to salinity, chlorination, heat, desiccation, and freezing. There was no decline in hatching success in response to salinity (up to 4 weeks at 35 g L21 salt) or chlorination (including up to 5 min at 3400 mg L21 chlorine). In response to heat there was an interaction between time and temperature; hatching occurred after exposure to 40uC for 1 min, 5 min, or 10 min but declined with the two longer exposures. Hatching also occurred after exposure to 50uC for 1 min, but no hatching followed exposure to 50uC for 5 min or to higher temperatures for 1 min. In response to desiccation at 17uC, exposure for # 4 h had no effect on hatching but $ 6 h resulted in no hatching. When frozen, hatching success depended on whether eggs were frozen in water or without water. Collectively, the results are congruent with an evolutionary origin of B. longimanus in permanent, euryhaline basins. The results advance our understanding of dispersal limits of B. longimanus, including vector potential, and may inform management practices for reducing range expansion of B. longimanus by humans.
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population regulation of the spiny water flea Bythotrephes longimanus in a reservoir implications for invasion
Limnology and Oceanography, 2012Co-Authors: Meghan E. Brown, Donn K Branstrator, Lyle J ShannonAbstract:We conducted a 3-yr study of the population dynamics of the invasive cladoceran Bythotrephes longimanus in Island Lake Reservoir (Minnesota) and compared our results to other human-constructed reservoirs and natural lakes to examine ecological differences of B. longimanus between these ecosystem types and to investigate how reservoirs facilitate invasion of this zooplankter. The maximum and mean densities (n 5 number of individuals) of B. longimanus were larger in Island Lake Reservoir (. 100 n m23 and 20–57 n m23, respectively) and in most other reservoirs than in natural lakes. Island Lake Reservoir and most other reservoir populations also exhibited multiple (up to six) cycles of growth and collapse per season, and performed extensive diel vertical migrations (DVM) to near the lake bottom during the day. Multiple lines of evidence indicate that the population dynamics of B. longimanus in Island Lake Reservoir were governed by relaxed top-down control by fish predation and strong bottom-up control by food availability. Developmental stage-specific death rates predicted from a matrix model were density dependent, aligned with predictions of bottom-up control (e.g., largest for the smallest instars, and correlated with food resources), and were inconsistent with anticipated prey demands by fishes. The reproductive and DVM trends of B. longimanus also indicated food stress and abated top-down control, respectively. We propose a mechanistic basis for invasion success in reservoirs by linking several limnological attributes, including chlorophyll a, water level fluctuation, light penetration, and thermal conditions to increased growth potential of B. longimanus.
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Patterns in the abundance, phenology, and hatching of the resting egg stage of the invasive zooplankter Bythotrephes longimanus: implications for establishment
Biological Invasions, 2011Co-Authors: Meghan E. Brown, Donn K BranstratorAbstract:To examine how dormancy contributes to the establishment and persistence of Bythotrephes longimanus, we investigated resting egg production and hatching in relation to the demography of the planktonic stage and environmental conditions in Island Lake Reservoir (USA). During a 3-year study, the largest contribution to the egg bank occurred in autumn and most eggs hatched in spring, but we also detected some resting egg production and hatching in summer. The difference between summer and late autumn densities of eggs in sediments averaged 47% (range 0–98%) for 18 sites throughout the reservoir, which was similar to experimental estimates of in situ hatching fraction of 67% for eggs in the spring and summer following their production. Based on emergence traps, neonates hatch in the field during May and June. We estimated mortality rates of 64% for resting eggs and embryos, and 59% for newly emerged neonates. Although hatching fraction saturated at the same level, eggs incubated offshore hatched later than those nearshore where water temperature was warmer and light was detectable at the sediment surface. Low dissolved oxygen concentration did not significantly reduce hatching fraction but resulted in some eggs that initiated development but failed to hatch. Collectively, our results demonstrate substantial annual turnover in the resting egg bank of B.longimanus and high mortality of resting eggs during recruitment from the egg to the first molt of the planktonic stage. These patterns suggest that propagule pressure in the form of resting eggs requires large numbers for establishment, and that considerable post-establishment resting egg production is necessary for inter-annual persistence.
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nature and nurture in dormancy dissolved oxygen ph and maternal investment impact Bythotrephes longimanus resting egg emergence and neonate condition
Canadian Journal of Fisheries and Aquatic Sciences, 2008Co-Authors: Meghan E. BrownAbstract:Bythotrephes longimanus (Onychopoda: Cercopagidae), an invasive zooplankter in North America, requires suitable habitat to satisfy its planktonic and resting stages, which occupy the pelagia and se...
Scott D Peacor - One of the best experts on this subject based on the ideXlab platform.
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factors affecting the vertical distribution of the zooplankton assemblage in lake michigan the role of the invasive predator Bythotrephes longimanus
Journal of Great Lakes Research, 2015Co-Authors: Paul E Bourdeau, Kevin L Pangle, Scott D PeacorAbstract:Abstract We analyze six years of survey data in Lake Michigan, which spanned large ranges in the abundance of the invasive predatory cladoceran Bythotrephes, to quantify the effect of this predator on the daytime vertical distribution of the nine most common species and life stages of Lake Michigan zooplankton. We found that Bythotrephes abundance and hypolimnion depth explained almost 50% of the variation in the vertical distribution of many zooplankton. Bythotrephes abundance was associated with significant and large (approximately 5–11 m) depth increases in cladocerans Daphnia and Bosmina, adult and copepodite stages of cyclopoid copepods, and adult diaptomid copepods Leptodiaptomus minutus, and Leptodiaptomus ashlandi; but did not significantly affect the depth of copepod nauplii, diaptomid copepodites, and adult Leptodiaptomus sicilis. Whereas other environmental factors, such as light attenuation coefficient, epilimnion and hypolimnion temperature, and sampling date significantly influenced the depth of various species and life stages, the inclusion of such environmental factors into linear models did not significantly lower the predicted influence of Bythotrephes. These results suggest that Bythotrephes abundance has a significant and large influence on the vertical distribution of a large component of the zooplankton assemblage in Lake Michigan. We argue that this pattern is driven by a Bythotrephes-induced anti-predator response in zooplankton prey. Such effects could lead to widespread growth costs to the zooplankton assemblage due to the colder water temperatures experienced at greater depths, which could in turn affect the rapidly changing Lake Michigan food web.
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Genetic and maternal effects on tail spine and body length in the invasive spiny water flea (Bythotrephes longimanus).
Evolutionary applications, 2011Co-Authors: Andrea L. J. Miehls, Scott D Peacor, Andrew G. McadamAbstract:Interest in the evolution of invasive species has grown in recent years, yet few studies have investigated sources of variation in invasive species traits experiencing natural selection. The spiny water flea, Bythotrephes longimanus, is an invasive zooplankton in the Great Lakes that exhibits seasonal changes in tail spine and body length consistent with natural selection. Evolution of Bythotrephes traits, however, depends on the presence and magnitude of quantitative genetic variation, which could change within or across years. Clonal analysis of wild-captured Bythotrephes indicated that variance components for distal spine length were variable among but not within years. Spine length was always heritable but was not always influenced by maternal effects. In contrast, variance components for body length varied both within and among years, but likewise body length was always heritable and not always influenced by maternal effects. Results indicate that important Bythotrephes traits have heritable variation comparable to native species and other invasive species that would enable an evolutionary response to natural selection. This evolutionary capacity could contribute to the widespread success and dramatic effects of Bythotrephes invasion in systems with diverse biotic and abiotic conditions.
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The spread, establishment and impacts of the spiny water flea, Bythotrephes longimanus, in temperate North America: a synopsis of the special issue
Biological Invasions, 2011Co-Authors: Brian Leung, Mark A. Lewis, Scott D PeacorAbstract:More than most sub-disciplines of ecology, the study of biological invasions is characterized by breadth rather than by depth. Studies of expanding ranges of invaders are common, as are post-invasion case studies, but we rarely have a deep understanding of the dynamics and regulators of the processes of invasion and resultant ecological transformations. This is unfortunate because such depth may well be needed to develop targeted, knowledge-based, management plans. In this collection we provide this needed depth of study of the key aspects of the invasion process for the spiny water flea, Bythotrephes longimanus . We do so by presenting the results of the work conducted by researchers in the Canadian Aquatic Invasive Species Network (CAISN), and several of their American and European collaborators over the past half decade. Given its rapid spread in the Great Lakes basin in North America, and the decreases in pelagic biodiversity that have ensued, the last decade has witnessed a surge of research on Bythotrephes . In this collection we learn much about mechanisms and dynamics of its spread, about the key role of humans in that spread, about the importance of Allee effects to establishment and persistence, about choices and parameterization of risk assessment models, about the value of comparing “effects” in native and invaded regions, about complex probable interactions of the invasion with impending changes in the climate, and about the regulators of the invader’s abundance and impacts. There should be much of interest in the collection for aquatic ecologists and invading species biologists alike.
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Light-dependent predation by the invertebrate planktivore Bythotrephes longimanus.
Canadian Journal of Fisheries and Aquatic Sciences, 2009Co-Authors: Kevin L Pangle, Scott D PeacorAbstract:We evaluated predation by the invasive invertebrate planktivore Bythotrephes longimanus on a Lake Michigan prey assemblage as a function of light intensity. Daphnia mendotae was the only prey type significantly reduced and light intensity strongly affected this reduction. Specifically, Bythotrephes consumption of D. mendotae was not detected under low light intensity ( 100 mmolm -2 � s -1 ) at which point Bythotrephes ingestion rate was 2.3 Daphnia per hour. These results indicate that By- thotrephes predation is more sensitive to light than previously thought, a discrepancy that can be explained after consider- ing the ability of D. mendotae to detect Bythotrephes' hydromechanic disturbance. The observed effect of light intensity on Bythotrephes predation is more like that of planktivorous fish than that of other previously studied invertebrate plankti- vores. Our findings elucidate the role that Bythotrephes plays in the food web and provide a novel explanation for its ten- dency to invade lakes of high water clarity. The importance of light-dependent predation found here may extend to other visually oriented predatory cladocerans. Resume´ : Nous evaluons la predation par l'invertebreenvahissant planctonophage Bythotrephes longimanus sur un ensem- ble de proies du lac Michigan en fonction de l'intensitelumineuse. Daphnia mendotae est le seul type de proie asubir une reduction significative et l'intensitelumineuse affecte fortement cette reduction. En particulier, on ne decele pas de con- sommation de D. mendotae par Bythotrephes aux faibles intensites lumineuses ( 100 mmolm -2 � s -1 )e t ace point, le taux d'ingestion de Bythotrephes est de 2,3 Daphnia par heure. Ces resultats indiquent que la predation de Bythotrephes est plus sensible ala lumiere qu'on ne le croyait anterieurement, un ecart qui peut s'expliquer si l'on tient compte de la capacitede D. mendotae adetecter la perturbation hydraulique causee par Bythotrephes. L'effet de l'intensitelumineuse observesur la predation chez Bythotrephes ressemble plus acelui qui se produit chez les poissons planctonophages que chez les autres invertebres planctonophages etudies. Nos observations mettent en lumiere le role joue ´ par Bythotrephes dans le reseau alimentaire et apportent une explication inedite ala tendance qu'a Bythotrephes aenvahir les lacs aeau tres claire. L'importance de la predation dependante de la lumiere s'applique peut-etre aussi ad'autres cla- doceres predateurs aorientation visuelle. (Traduit par la Redaction)
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large nonlethal effects of an invasive invertebrate predator on zooplankton population growth rate
Ecology, 2007Co-Authors: Kevin L Pangle, Scott D Peacor, Ora E JohannssonAbstract:We conducted a study to determine the contribution of lethal and nonlethal effects to a predator's net effect on a prey's population growth rate in a natural setting. We focused on the effects of an invasive invertebrate predator, Bythotrephes longimanus, on zooplankton prey populations in Lakes Michigan and Erie. Field data taken at multiple dates and locations in both systems indicated that the prey species Daphnia mendotae, Daphnia retrocurva, and Bosmina longirostris inhabited deeper portions of the water column as Bythotrephes biomass increased, possibly as an avoidance response to predation. This induced migration reduces predation risk but also can reduce birth rate due to exposure to cooler temperatures. We estimated the nonlethal (i.e., resulting from reduced birth rate) and lethal (i.e., consumptive) effects of Bythotrephes on D. mendotae and Bosmina longirostris. These estimates used diel field survey data of the vertical gradient of zooplankton prey density, Bythotrephes density, light intensity, and temperature with growth and predation rate models derived from laboratory studies. Results indicate that nonlethal effects played a substantial role in the net effect of Bythotrephes on several prey population growth rates in the field, with nonlethal effects on the same order of magnitude as or greater (up to 10-fold) than lethal effects. Our results further indicate that invasive species can have strong nonlethal, behaviorally based effects, despite short evolutionary coexistence with prey species.
Donn K Branstrator - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of a method that uses one cubic meter mesocosms to elucidate a relationship between inoculation density and establishment probability for the nonindigenous, invasive zooplankter, Bythotrephes longimanus
Biological Invasions, 2019Co-Authors: Donn K Branstrator, Matthew C. Teneyck, Euan D. Reavie, Mathew A. Etterson, Allegra A. CangelosiAbstract:The introduction and spread of aquatic invasive species by ships is a global concern, and development and implementation of effective prevention measures are an urgent priority. Two questions plague science and policy. First, what level of reduction in live organism discharges from ships yields a given desired level of reduction in species establishment probability? Second, how can this question be empirically tested in a practicable and replicable manner? We evaulated the extent to which experiments using 1 m^3 mesocosms could help elucidate a relationship between inoculation density and reproductive output (a proxy for establishment probability) of a surrogate invader, Bythotrephes longimanus (Crustacea: Cladocera). The inoculation densities were 1, 5, 10, 20, or 40 individuals m^−3. All individuals in each inoculum were added as a single event at the start of each of four, two-week-long experiments. B. longimanus were inoculated into ambient water pumped from the Duluth-Superior Harbor at the start of each experiment between June and August, 2015. The mesocosm volume and range of inoculation densities has relevancy to the International Maritime Organization’s Ballast Water Management Convention D2 standard which allows a density of 50 μm minimum dimension. Reproductive output was detected among 78 of 80 mesocosms after 2 weeks. Among 13 abiotic and biotic variables, inoculation density was overwhelmingly the best predictor, and water temperature was the second best predictor, of B. longimanus reproductive output. Net reproductive value of the inoculants was ≥ 1 among 35 of 80 mesocosms after 2 weeks. There was evidence for density-dependent reduction in population growth rate in the higher inoculation density mesocosms. We examined various parts of our method for robustness. Translation of the results into meaningful estimates of establishment probability in the field remains a vivid challenge. We introduce the idea of using annual hatching rates of natural banks of dormant eggs in lake sediments as a method to characterize relationships between propagule pressure and establishment probability at the scale of an ecosystem for seasonally transient species such as B. longimanus .
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changes in the cladoceran community of lake superior and the role of Bythotrephes longimanus
Journal of Great Lakes Research, 2017Co-Authors: Matthew B Pawlowski, Donn K Branstrator, Thomas R Hrabik, Robert W SternerAbstract:Abstract Introductions of Bythotrephes longimanus have resulted in reduced cladoceran species richness and biomass in the Laurentian Great Lakes and many inland lakes. Bythotrephes was first observed in Lake Superior in 1987 but its effect on the cladoceran community has been unknown. We compared the composition of the offshore cladoceran community of Western Lake Superior during 2014 and 2015 to zooplankton surveys from 1971–2001 to determine whether changes in the cladoceran community have occurred. Monthly comparisons show that the contribution of Bosmina longirostris to offshore cladoceran numbers was generally twice as much in the 1970s than during 2014–2015 while the relative contribution of Daphnia mendotae increased after the 1970s. These community changes are consistent with changes due to Bythotrephes observed in other lakes. To evaluate evidence for the role of Bythotrephes in these community changes, we used data from 2014–2015 to analyze patterns in spatial and vertical overlap between Bythotrephes and its cladoceran prey species (Bosmina, Daphnia, and Holopedium) and compared estimates of consumption by Bythotrephes to production of these potential prey. Bosmina was the species whose vertical position and rate of production made it most vulnerable to suppression by Bythotrephes. Of the potential cladoceran prey species, Bosmina densities were also the most negatively correlated with Bythotrephes densities. These findings support a hypothesis of top-down effects on Bosmina by Bythotrephes in Lake Superior. This work informs future zooplankton research in Lake Superior and furthers our understanding of the effects of Bythotrephes on the Lake Superior food web.
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colonization dynamics of the invasive predatory cladoceran Bythotrephes longimanus inferred from sediment records
Limnology and Oceanography, 2017Co-Authors: Donn K Branstrator, Meghan E. Brown, Ashley E Beranek, Leif K Hembre, Daniel R EngstromAbstract:Despite the central role of colonization to invasion biology, little is known about the early dynamics of founder populations because this time period is often unobserved and short-lived. This study documents with high resolution the early population ecology of an invading freshwater zooplankton, Bythotrephes longimanus (Cladocera : Cercopagidae), by measuring accumulation rates of its caudal spine in sediments. Using dated (210Pb and 137Cs) sediment cores from four spatially distinct sites in Island Lake Reservoir (Minnesota, USA), we describe its first presence, early distribution, growth trajectory, and early impacts on prey. The sediment record shows that B. longimanus first appeared and was widely distributed in the lake in 1982 (± 2 yr, standard deviation), 8 yr before its first detection in the water, making it one of the earliest documented invasions in North America and suggesting that ecosystems may serve as dispersal hubs for years prior to detection. Logistic growth models describing spine accumulation rates show that B. longimanus required about two decades to achieve an annual equilibrium (K). Prolonged buildup to K may owe to several factors, including accumulation of a sufficiently large bank of resting eggs, the obligate overwintering life stage. Early exponential growth was incongruent with the presence of a lag phase. Post invasion, Daphnia mendotae became proportionally the most abundant daphniid in the lake, but the timing of the switch in prey species composition coincided more with the proliferation of B. longimanus density and its attainment of K than with its arrival to the lake.
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the north american invasive zooplanktivore Bythotrephes longimanus is less hypoxia tolerant than the native leptodora kindtii
Canadian Journal of Fisheries and Aquatic Sciences, 2017Co-Authors: Michael L Sorensen, Donn K BranstratorAbstract:The predatory cladoceran Bythotrephes longimanus (spiny water flea) has been invading lakes and damaging food webs across the central part of North America since the early 1980s. To understand its niche and that of the taxonomically related and native predatory cladoceran Leptodora kindtii, we investigated species survival after 12 h exposures to low dissolved oxygen (DO) concentrations in the laboratory. Bythotrephes longimanus (n = 690) exhibited a hypoxia tolerance limit (LC50) of 1.65 mg·L−1 DO (95% confidence interval: 1.59, 1.72 mg·L−1) and was significantly less tolerant of hypoxia than L. kindtii (n = 380), which exhibited an LC50 of 0.58 mg·L−1 DO (0.51, 0.65 mg·L−1). These lab-based physiological results are consistent with landscape-scale observations that B. longimanus successfully invades primarily mesotrophic and oligotrophic lakes, while L. kindtii inhabits a wider range of lakes that includes eutrophic ones. Climate change throughout the 21st century may increase the occurrence and severit...
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analysis of invertebrate resting eggs and other biota in ballast tank sediment of domestic great lakes cargo ships
Journal of Great Lakes Research, 2015Co-Authors: Donn K Branstrator, Kelly L Westphal, Breana K KingAbstract:Abstract Domestic shipping in the Laurentian Great Lakes may be a vector of secondary spread for non-native species, but research has not yet assessed the role of ballast tank sediment. Here, ballast tank sediment was collected from three domestic ships ( M/V American Century , M/V Edwin H. Gott , and M/V Mesabi Miner ) during 2011 and 2012 at Lake Superior harbors in the USA and analyzed for invertebrates. Samples contained evidence of active life stages of Bivalvia, Cladocera, Copepoda, Gastropoda, Hydracarina, Nematoda, Oligochaeta, and Ostracoda as well as dormant life stages of some species including ones hatched in the laboratory from Cladocera, Copepoda, Ostracoda, and Rotifera. Excluding resting eggs, the groups Bivalvia, Copepoda, and Ostracoda comprised 83% of individuals recovered. The mean density of resting eggs per ballast tank ranged from 16.0 to 24.8 eggs/g wet sediment for samples collected during November and from 0.2 to 2.7 eggs/g wet sediment for samples collected during December to March. The mean viability (percentage hatched) of resting eggs per ballast tank ranged from 31.2% to 75.8% for samples collected during November; December to March samples were not assessed for egg viability. Bosminidae (Cladocera) were the most commonly hatched taxa and comprised 548 of 819 hatchlings (or 67%). Hatched eggs included Eubosmina coregoni and Bythotrephes longimanus which are non-native to the Great Lakes. Densities of resting eggs and other biota were comparable to, or greater than, published densities of organisms in ballast tank sediment of foreign ships entering the Great Lakes and ballast tank water of domestic ships operating within the Great Lakes.
Shelley E Arnott - One of the best experts on this subject based on the ideXlab platform.
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anti predator behaviour of native prey daphnia to an invasive predator Bythotrephes longimanus is influenced by predator density and water clarity
Hydrobiologia, 2019Co-Authors: Sarah Hasnain, Shelley E ArnottAbstract:Bythotrephes longimanus is an invasive zooplankton predator, negatively impacting zooplankton abundance and diversity in North American lakes. Previous studies have shown that Daphnia populations in lakes move to deeper waters during the day, in the presence of Bythotrephes, a visual predator occupying well-lit regions. However, Daphnia vertical position can be influenced by a variety of biotic and abiotic factors. We conducted a survey to determine (1) if Daphnia daytime vertical position differed between invaded and uninvaded lakes and (2) if Daphnia vertical position in invaded lakes was affected by water chemistry variables linked to water clarity, UV exposure, and phytoplankton production, and Bythotrephes density. Invaded lakes had a lower proportion of epilimnetic Daphnia as compared to uninvaded lakes. Daphnia vertical position was species-dependent, and with a lower proportion of epilimnetic Daphnia mendotae and greater proportion of epilimnetic D. longiremis observed in invaded lakes. D. mendotae were deeper in the water column in high Bythotrephes density lakes with low dissolved organic carbon levels. Our results show Daphnia vertical position response to Bythotrephes is species specific, dependent on Bythotrephes density and influenced by local abiotic conditions, with important implications for community structure and ecosystem function in invaded lakes.
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the effects of Bythotrephes longimanus and calcium decline on crustacean zooplankton communities in canadian shield lakes
Hydrobiologia, 2017Co-Authors: Shakira S E Azan, Shelley E ArnottAbstract:Declining calcium concentrations and invasion by Bythotrephes longimanus are two important, often co-occurring, stressors affecting Canadian Shield lakes. However, there has been no experimental examination of how they might jointly influence zooplankton communities. We conducted a 6-week field mesocosm experiment in Havelock Lake, Haliburton, Ontario, Canada to examine the individual and joint effects of Bythotrephes and calcium along a gradient ranging from 1.2 to 2.6 mg/l on zooplankton communities. Although densities of Bythotrephes in our study are unknown, it significantly reduced total zooplankton abundance in invaded compared to uninvaded treatments by 46%, with the greatest impacts on small cladocerans and daphniids. Low calcium reduced total zooplankton and cladoceran abundances. Although Havelock Lake has the lowest calcium concentration among invaded lakes in the Muskoka–Haliburton region (1.2 mg Ca/l), an effect of calcium on individual species abundances was not detected. Additionally, we did not detect an interactive effect of both stressors. Our results suggest that lake calcium concentration may not yet be low enough to effect a strong response. However, as Bythotrephes continue to invade low calcium lakes, and as calcium concentrations further decline, we may see larger impacts on cladocerans as calcium thresholds for reproduction and growth are reached.
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a review of the effects of Bythotrephes longimanus and calcium decline on zooplankton communities can interactive effects be predicted
Environmental Reviews, 2015Co-Authors: Shakira S E Azan, Shelley E Arnott, Norman D. YanAbstract:Anthropogenic stressors including acid deposition, invasive species, and calcium (Ca) decline have produced widespread damage to Canadian Shield lakes, especially to their zooplankton communities. Here, we review current knowledge on the individual effects on zooplankton by the non-indigenous predator Bythotrephes longimanus and Ca decline; we identify knowledge gaps in this literature and examine the likely interactive impacts of Bythotrephes invasions and Ca decline on zooplankton. The negative impacts of Bythotrephes longimanus on zooplankton communities are well known, whereas current understanding of the effects of declining Ca on zooplankton is restricted to Daphnia spp.; hence, there is a large knowledge gap on how declining Ca may affect zooplankton communities in general. The co-occurring impacts of Bythotrephes and declining Ca have rarely been studied at the species level, and we expect daphniids, particularly Daphnia retrocurva and Daphnia pulicaria, to be the most sensitive to both stressors....
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influence of light on the foraging impact of an introduced predatory cladoceran Bythotrephes longimanus
Freshwater Biology, 2013Co-Authors: Anneli Jokela, Shelley E Arnott, Beatrix E BeisnerAbstract:Summary Identifying factors that influence the foraging ability of an introduced predator is essential for assessing its potential impact on the invaded community. We conducted a series of in situ enclosure experiments to determine the effect of light on the foraging ability and community-level effects of the invasive cladoceran Bythotrephes longimanus in lakes. In 1-L enclosures with only Daphnia prey, a strong effect of predation under ambient light conditions was observed. There was no evidence of predation in dark treatments, suggesting that Bythotrephes is unable to feed by mechanoreception alone. A subsequent experiment using larger enclosures exposed an assemblage of prey from an uninvaded lake to Bythotrephes predation across a similar light gradient. Consistent with regional lake surveys, Bythotrephes reduced cladoceran abundance under ambient light conditions. At the community level, predation effects were overall strongest under ambient light; however, the influence of light on predation varied across trials that differed in initial community structure of prey. Also, some predation under dark conditions was possible on Ceriodaphnia and Bosmina, suggesting that Daphnia, in particular, may be less vulnerable under low-light conditions. Our results suggest that light refuges for some prey taxa could play an important role in mediating the impact of Bythotrephes.
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patterns of Bythotrephes longimanus distribution relative to native macroinvertebrates and zooplankton prey
Biological Invasions, 2011Co-Authors: Anneli Jokela, Shelley E Arnott, Beatrix E BeisnerAbstract:As exotic species are introduced and spread across a heterogeneous landscape, the abundance and richness of potential competitor and prey species they encounter will vary. Little is known about the interactions between Bythotrephes longimanus and native predatory macroinvertebrates (e.g., Mysis, Chaoborus), which potentially limit the establishment and spread of the invader. An 80-lake survey was conducted in the summer of 2007 to obtain macroinvertebrate abundances across invaded and non-invaded lakes. A subset (15) of these lakes was surveyed more intensively to obtain stratified daytime and night-time distributions of the organisms. Overall co-occurrence of Bythotrephes with native macroinvertebrate predators was widespread across lakes indicating that the presence of native macroinvertebrates alone is unlikely to limit the establishment of Bythotrephes. However, we did find an effect of native macroinvertebrate predators on the vertical distribution of Bythotrephes: as native macroinvertebrate abundances increased, the relative abundance of Bythotrephes in the epilimnion increased. Furthermore, the relative abundance of some zooplankton prey (e.g., Daphnia) was lower in the epilimnion when Bythotrephes abundance was high. Although we cannot rule out consumptive effects, some evidence suggests an avoidance behavioural response in the prey. While the underlying mechanisms of these distributional shifts remain unclear, our results suggest that interactions between Bythotrephes, native macroinvertebrates and zooplankton prey are complex, highlighting the need to further examine these interactions.
