Browsing by Subject "Common Carp"

Now showing 1 - 3 of 3
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    Effects of bluegill predation, lake productivity, and juvenile dispersal on common carp recruitment dynamics in lake-marsh systems in Minnesota
    (2016-02) Lechelt, Joseph
    Processes that regulate common carp (Cyprinus carpio) recruitment (i.e. survival of eggs, larvae and juveniles) are largely unknown. In interconnected lake-marsh systems of Minnesota, young of year (YOY) carp are generally found in marshes that winterkill and lack bluegill sunfish (Lepomis macrochirus), an abundant native predator. This suggests that bluegills might function as a biocontrol agent for carp. Further, whereas YOY carp are commonly found in winterkill marshes of south-central Minnesota, they are not found in similar systems in northern Minnesota where lake productivity is much lower, suggesting an aquatic productivity bottleneck on carp recruitment. Finally, in marshes where carp recruit (productive and bluegill-free), YOY must disperse into adjacent lakes to drive high population abundance. In this study, I conducted three experiments to test 1) the effect of bluegills on carp recruitment; 2) the effect of aquatic productivity on larval carp survival, growth and diet; 3) natural dispersal tendencies of YOY carp from a marsh into an adjacent lake. The first experiment employed four (20 m diameter) impermeable enclosures from 2011-2014. Each year, enclosures were stocked with carp eggs and every other one was stocked with bluegills. Backpack electrofishing surveys conducted five weeks later showed that carp catch per unit of effort (CPUE) was over 10-fold lower in the enclosures stocked with bluegills than in the controls. The second experiment, conducted in 2014 and 2015 used aquaria stocked with carp larvae and supplied with zooplankton densities and community structures from lakes of three different trophic states (oligo-, meso-, and eutrophic). It showed that carp larvae selectively consumed macrozooplankton (> 200 μm) and their growth rates were highest in the eutrophic lake and lowest in the oligotrophic lake. Survival, however, was high in all treatments. The third study was conducted in a natural lake-marsh system and utilized passive integrated transponder (PIT) tags to quantify the outmigration of YOY carp from the marsh to the lake. It showed that < 6% YOY carp outmigrated to the lake, supporting previous indirect estimates. The results of these three studies are important to understanding recruitment dynamics of carp in lake-marsh systems in Minnesota.
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    Making the Minnehaha: The Reengineering of a Creek and the Creation of an Envirotechincal System
    (2019-05) Froiland, Samuel
    This history documents the transformation of the Minnehaha Creek from the signing of the treaties of Traverse des Sioux and Mendota in the 1850s, which enabled the settlement of the Minnehaha Creek by American settler-colonists and the statehood of Minnesota, to the visit of President Lyndon Baines Johnson to the Minnehaha Falls in 1964. Located along the southern edge of Minneapolis, Minnesota and its south and western suburbs, the Minnehaha Creek is a twenty-two-mile-long waterway connecting Lake Minnetonka and the Mississippi River. Central in this history is confronting uncritical appraisals of the Minnehaha Creek’s naturalness and uncovering the role technology and culture has played in the transformation of the waterway. Because the Minnehaha’s waterfall has been a tourist attraction for more than one-hundred and seventy years, it has been regarded as being one of Minneapolis’s great “natural” treasures. However, this history of the Minnehaha Creek complicates uncritical appraisals of the Minnehaha Creek’s naturalness, or its “natural mythology,” by showing that the Minnehaha, first through the installation of gristmills, then through the construction of a dam at its headwaters, and last through the creation of parklands, has been transformed into an envirotechnical system. That is, a system where nature, culture, and the artifacts of humanity have melded together to form a system that can no longer be explained by one of these forces alone. By uncovering the technology and ideology embedded in the Minnehaha, and how the Minnehaha itself has been turned into a technology, this history presents itself as a case study about how technology is used to express values and priorities on environments and the mythologies we develop to legitimate and rationalize the new environments we create.
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    Seasonal influence on detection probabilities for multiple aquatic invasive species using environmental DNA
    (2023-12-14) Rounds, Christopher; Arnold, Todd W; Chun, Chan Lan; Dumke, Josh; Totsch, Anna; Keppers, Adelle; Edbald, Katarina; García, Samantha M; Larson, Eric R; Nelson, Jenna KR; Hansen, Gretchen JA; round060@umn.edu; Rounds, Christopher; University of Minnesota Fisheries Systems Ecology Lab
    Aquatic invasive species (AIS) are a threat to freshwater ecosystems. Documenting AIS prevalence is critical to effective management and early detection. However, conventional monitoring for AIS is time and resource intensive and is rarely applied at the resolution and scale required for effective management. Monitoring using environmental DNA (eDNA) of AIS has the potential to enable surveillance at a fraction of the cost of conventional methods, but key questions remain related to how eDNA detection probability varies among environments, seasons, and multiple species with different life histories. To quantify spatiotemporal variation in the detection probability of AIS using eDNA sampling, we surveyed 20 lakes with known populations of four aquatic invasive species: Common Carp (Cyprinus carpio), Rusty Crayfish (Faxonius rusticus), Spiny Waterflea (Bythotrephes longimanus), and Zebra Mussels (Dreissena polymorpha). We collected water samples at 10 locations per lake, five times throughout the open water season. Quantitative PCR was used with species-specific assays to determine the presence of species DNA in water samples. Using Bayesian occupancy models, we quantified the effects of lake and site characteristics and sampling season on eDNA detection probability. These results provide critical information for decision makers interested in using eDNA as a multispecies monitoring tool and highlight the importance of sampling when species are in DNA releasing life history stages.