Browsing by Subject "lakes"
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Item 2002 Water Quality Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2003) Minnesota Center for Survey ResearchItem Abiotic Mechanisms for Cyanobacteria Physiology and Distribution in Lakes: A Multi-Scale Approach(2018-05) Wilkinson, AnneHarmful Algal Blooms (HABs) are a ubiquitous ecological and public health hazard because they are comprised of potentially toxic freshwater microorganisms, called cyanobacteria. Cyanobacteria are capable of accumulating in large concentrations in fresh-water ecosystems during summer and producing a toxin (microcystin) that in high concentration can be harmful to humans and animals. The occurrences of toxic HABs are highly spatially and temporarily variable in freshwater ecosystems and are difficult to predict. These HABs can be governed by abiotic environmental conditions including water temperature structure, light, nutrient abundance, and mixing. This dissertation increases the understanding of abiotic environmental conditions, i.e. different mixing scales, on the physiology and distribution of cyanobacteria in nutrient invariant eutrophic systems using field and laboratory studies. In the laboratory, we investigated the effect of small-scale turbulence on the growth and metabolism of Microcystis aeruginosa. The laboratory bioreactor setup included two underwater speakers, generating a quasi-homogeneous turbulent flow, comparable to field values in the lacustrine photic zone (Reλ =0, Reλ =33 and Reλ =15). The results suggest that turbulence mediates the metabolism of Microcystis aeruginosa, quantified by the net oxygen production, oxygen uptake, and inorganic carbon uptake, which is not manifested in changes in growth rate. In the field, we investigate the abiotic drivers for cyanobacteria and microcystin vertical distribution using a research station to quantify a wide range of local meteorological conditions, water temperature, and water chemistry, including phycocyanin, in two different eutrophic stratified Minnesota lakes. The monitoring effort was coupled with discrete weekly sampling measuring nutrients, cyanobacteria composition, and microcystin concentrations. Our objective was to describe the distributions of cyanobacteria biovolume (BV) and microcystin concentrations (MC) using easily measurable physical lake parameters. The analysis of vertical heterogeneity of cyanobacteria in the entire water column revealed high positive correlations among BV stratification, surface water temperature, stratification stability, quantified by the Schmidt stability. During strong stratification, the MC and BV accumulated above the thermocline and were highly correlated. Although, the cyanobacteria BV is significant only above the thermocline during stratification where cyanobacteria are exposed to high phosphate, temperature and light, there is still further vertical variability to explain within this region. Two types of BV distributions were observed above the thermocline. The first distribution depicted BV uniformly distributed over the diurnal surface mixed layer (SL). The second BV distribution displayed local BV maxima near and under the surface in the SL. A quantitative relationship was developed to determine the probability of observing a uniform distribution as a function of the surface Reynolds number (ReSL), the dimensionless ratio of inertial to viscous forces, over the SL. The uniform distribution was observed for ReSL>50,000. The outcome of this analysis is the first step towards the quantification and prediction vertical stratification of cyanobacteria biovolume and microcystins as a function of local meteorological and physical conditions in a stratified lake.Item Bulletin No. 35. The Lakes of Minnesota Their Origin and Classification(Minnesota Geological Survey, 1952) Zumberge, James H.The most distinctive features of the surface of Minnesota are the thousands of lakes scattered irregularly over the state. Even casual observation reveals the fact that these lakes vary greatly in their character. This means that they have been formed in different ways closely related to the geologic history of the region. There are scattered references to the origin of specific lakes particularly in the Annual Reports and the volumes of the Final Reports of the Geological and Natural History Survey of Minnesota. There has been, however, a lack of any single systematic treatment of the geologic factors involved in the formation of the lakes. It is evident that such a geologic basis is desirable for all scientific and practical work on the lakes which form such a valuable resource. For this reason Dr. Zumberge was supported in his field work by funds allotted by the University of Minnesota to the Minnesota Geological Survey, a unit in the College of Science, Literature, and the Arts. Appreciation is due Dr. Zumberge for his painstaking work, particularly in revising his doctoral thesis to make it into a bulletin for the Geological Survey series - a task performed without remuneration. The Director also wishes to express his thanks to all who helped Dr. Zumberge in his work.Item California Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2001) Minnesota Center for Survey ResearchItem Computing water flow and storage in complex landscapes(2020-12) Callaghan, KerryDepressions in the landscape can hold water, forming lakes or, on a smaller scale, puddles. Some of these features form long-term water stores, while others are ephemeral, filling and emptying as local weather conditions change. They impact hydrologic connectivity as they either store incoming water, or allow it to pass through them to another portion of the hydrologic system. Surface-water contained in these depressions also interacts with local groundwater. Despite these interactions, many flow-routing algorithms require the complete removal of depressions from a landscape by filling or carving. Resultant flow-routing surfaces can host a continuous, integrated drainage network, but lose information about possible surface-water storage and interruptions to the flow network. I first present an initial answer to this problem: FlowFill, an algorithm that routes a prescribed amount of runoff across the surface in order to flood depressions, but only if enough water is available. FlowFill is useful both in determination of flow-routing surfaces, and in visualisation of changing hydrology through time. I then present Fill-Spill-Merge, a method that rapidly processes and distributes runoff to and through depressions. Fill-Spill-Merge makes use of a depression hierarchy data structure which records information about depressions and their relationships to one another. Fill-Spill-Merge produces appropriate flow-routing surfaces up to 2,600 times faster than FlowFill. Finally, I couple Fill-Spill-Merge with a groundwater module in the Water Table Model. The Water Table Model is capable of computing changes in water table elevation at large spatial scales and over long temporal scales. It incorporates lakes into water table elevation estimates and enables assessments of changing terrestrial water storage through time. I demonstrate an application of the Water Table Model in North America’s Great Basin, where a suite of model runs reveals past hydroclimate.Item Continuation of Studies on the Hydrology of Ponds and Small Lakes(Minnesota Agricultural Experiment Station, 1971) Allred, E. R.; Manson, P. W.; Schwartz, G. M.; Golany, Pinhas; Reinke, J. W.Item Data in Support of Widespread declines in walleye recruitment following zebra mussel invasion in Minnesota lakes(2023-04-26) Kundel, H; Hansen, Gretchen J A; kunde058@umn.edu; Kundel, H; University of Minnesota Dr. Hansen Research TeamInvasive zebra mussels (Dreissena polymorpha) alter lake ecosystems and can negatively affect first-year growth of walleye (Sander vitreus), potentially lowering walleye overwinter survival and recruitment success. Zebra mussel effects also vary among lakes, and walleye resilience to the effects of zebra mussels may vary depending on lake characteristics (e.g., depth, clarity) or fish community composition. To test these hypotheses, we used data from 1,438 surveys across 348 lakes collected between 1993 and 2019 to measure walleye recruitment, defined as relative abundance of age-0 walleye in their first fall. We fitted Bayesian hierarchical models to quantify the effects of zebra mussels on walleye recruitment while accounting for the effects of lake temperature, surface area, and water clarity. A before-after-control-impact (BACI)-like design was used to account for potential changes in recruitment due to factors other than zebra mussel invasion. Age-0 walleye recruitment to their first fall was ~41% lower (95% credible interval of 38 - 44%) in lakes containing zebra mussels compared to uninvaded lakes. Invaded lakes had higher recruitment prior to zebra mussel invasion than lakes that remain uninvaded. Conversely, walleye recruitment increased slightly (7% (95% credible interval 2 - 11%)) in lakes without zebra mussels over the same time period. Walleye recruitment was higher in larger lakes and lakes with lower water clarity. Water temperature, as indexed by degree days (base 5 °C), did not affect walleye recruitment. Our results demonstrate negative effects of zebra mussel invasion on walleye population dynamics at a landscape scale.Item Digitization of Minnesota and Wisconsin bathymetric maps resulting in hypsographic data(2020-09-09) Rounds, Christopher I; Hansen, Gretchen JA; Vitense, Kelsey; Van Pelt, Amanda; round060@umn.edu; Rounds, Christopher; University of Minnesota Fisheries Ecosystem Ecology LabThe data set includes hypsographic data (area-at-depth) for over 750 Minnesota and Wisconsin lakes throughout the states. The majority of these lakes (650+) did not have publicly available hypsography. The hypsography was derived by digitizing bathymetric DNR maps using ImageJ. One hundred Minnesota lakes were selected that had DNR hypsographic data (in the form of a DEM) available and a comparison between the hypsographic data derived from DEMs and ImageJ was completed. These results, as well as code and hypsographic data is all available. The purpose of this work was to release broad scale lake area-at-depth data for limnological and aquatic biology studies.Item GIS Based Wetland Assessment Methodology for Urban Watershed Planning(1997) Snyder, Douglas J.Item Identifying and Interpreting Contemporary Wild Rice Habitat in Ceded Chippewa Lands of Northern Minnesota.(Center for Community & Regional Research, College of Liberal Arts, University of Minnesota, Duluth., 1995) Henderson, Martha LItem Kansas Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2001) Minnesota Center for Survey ResearchItem Lakes in Ramsey County: Recreational Resource Use - Policy Implications. Report No. 4.(Center for Urban and Regional Affairs, University of Minnesota., 1973) Wietecki, Keith; Orning, George W.Item The Land Of Blue Green Waters? Describing The Algal Community Dynamics Of Six Minnesota Lakes By Examining Cyanobacterial Dominance And Toxicity(2020-02) Bambach, MatthewCyanobacteria are a diverse and ancient group of phytoplankton that are a normal component of aquatic primary producer communities. They can become a problem when they reach high cell densities and form blooms capable of producing toxins that can threaten human and wildlife populations. These occurrences are referred to as cyanobacterial harmful algal blooms (cHABs). Increasing global cHAB frequency and potency have been attributed to warming temperatures and nutrient over-enrichment, but drivers of local and regional occurrence remain poorly understood. In this thesis, I examined six inland Minnesota lakes with different physical, chemical, and biological attributes to highlight patterns in cyanobacterial dominance of the phytoplankton community and understand which lake attributes were closely related to cHAB activity, with a focus on the cyanotoxin Microcystin, from June to September in 2016 and 2017. Cyanobacteria were found to dominate most study lakes, and visible blooms were observed at southern, central, and northern latitude lakes. Microcystin-producing taxa were observed in all study lakes. July and August were the months most likely to experience cHABs, and 2017 showed increased cHAB activity associated with elevated algal biovolume across systems. Specific drivers of cHABs differed among study lakes, but aggregated data for all lakes suggests that increased cyanobacterial dominance of the phytoplankton, total kjeldahl nitrogen, and chlorophyll-a pigment were the attributes most closely associated with harmful conditions. Finally, different harmfulness metrics to safeguard the public from cHABs are compared to discuss their respective protectiveness.Item Michigan 2003 Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2004) Minnesota Center for Survey ResearchItem Minnesota Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2001) Minnesota Center for Survey ResearchItem Ohio Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2001) Minnesota Center for Survey ResearchItem Oregon 2003 Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2004) Minnesota Center for Survey ResearchItem Pennsylvania Aquatic Nuisance Species and Boating Survey: Results and Technical Report.(Minnesota Center for Survey Research (MCSR), 2003) Minnesota Center for Survey Research