Browsing by Subject "pollution"

Now showing 1 - 20 of 20
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    August 1982 Root River Dye Trace
    (Journal of Freshwater, 1982) Alexander Jr., E Calvin
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    Columbia Park Environmental Profile.
    (1995) Ek, Scott E.
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    Developmental influences on stress-based responses to environmental change
    (2023-05) Shephard, Alexander
    A central goal in ecology, evolution, and behavior (EEB) is to understand how individuals and populations respond to environmental change. Many forms of environmental change are stressful, leading to functional impairments, fitness declines, and loss of genetic diversity from natural populations. In this dissertation, I consider factors that explain why organisms vary in their abilities to tolerate stressful environments. Taking a developmental approach, I address this question in the context of three research domains within the broader field of EEB: (1) the evolution of phenotypic plasticity, (2) life history evolution and senescence, and (3) population responses to anthropogenic change. In data chapter 1, I use a nematode (Caenorhabditis elegans) to test the hypothesis that genetic variation in generalized plastic responses to stress is associated with reproductive costs. Consistent with a cost of plasticity, I find that genotypes capable of a higher degree of stress response plasticity exhibit lower reproductive performance under non-stressful conditions. In data chapter 2, I use migratory North American monarch butterflies (Danaus plexippus) to test how metabolic stress influences life history variation. I find that increased flight activity early in adulthood promotes butterfly longevity and somatic tissue antioxidant production, supporting the idea that metabolic stress is a driver of life history plasticity. In data chapters 3 – 7, I use two butterfly species, D. plexippus and Pieris rapae (the cabbage white), to test a range of hypotheses related to developmental mechanisms associated with tolerance to novel anthropogenic stressors such as heavy metal and salt pollution. In chapters 3 – 4, I find support for the hypothesis that variation in heavy metal tolerance is related to organismal condition (i.e., the total amount of energetic resources individuals can acquire throughout development). In Chapters 5 – 6, I ask how anthropogenic increases in nutrient availability influence the emergence of life history variation. In chapter 7, I show that heavy metal tolerance can vary among insect pollinator species, and I highlight the need for more research on heavy metal tolerance in species of conservation concern. Overall, this work, shows that considering developmental mechanism can help predict stress-based responses to environmental change among a range of disciplines within EEB.
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    Effects of Enrichment on Lake Superior Periphyton
    (Water Resources Research Center, University of Minnesota, 1973-05) Krogstad, B.O.; Nelson, R.R.; Odlaug, T.O.; Olson, T.A.; Ruschmeyer, O.R.
    The primary objective of this research as carried out in the summer and fall of 1969 and 1970 was to determine the possible changes which would take place in Lake Superior periphvton when polluting or enriching substances were added to the lake Hater. To this end, two natural rock basins were constructed at the lakeside along the north shore at Castle Danger, Minnesota for the purpose of exposing naturcll1y grown and regrowth periphyton to higher-than-normal levels of phosphate and nitrate. At weekly intervals, samples were collected and productivity was measured by enumeration of organisms, chlorophyll analysis, and weight, dry and organic. Lake Superior periphyton responds dramatical1 y to increased additions of phosphorus and nitrogen. If the near-shore area of Lake Superior ever received nutrients, such as those added to the experimental test pool at Castle Danger, a drastic change in the Lake.'s biota could occur. For example, as enrichment increased, the predominant clean-water diatom forms could eventually be replaced by the more tolerant green or blue-green algae. In addition, the very composition of the macrobenthic forms found in Lake Superior could be altered as a result of their dependence on the periphyton, which, as primary producers, form the first link in the food chain. Likewise, certain fish which depend on benthic organisms for their food may be adversely affected as an indirect result of a changing periphyton community. Having established that enrichment of Lake Superior water will drnmatically change the normal periphyton growth, another baseline has been established for future reference in the event that phosphorus and nitrogen rich wastes should be added to the 1ake. If certain types of algae appear as replacements of the normal flora now characterizing the periphyton and the productivity increases, one will have a means [or assessing the possible changes taking place in the water quality of Lake Superior.
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    An Examination Of What Causes Pollution and Resource Depletion
    (Hubert H. Humphrey Institute of Public Affairs, 2009-01-30) Walter, David E.
    What is it that drives humans to pollute and deplete resources to the extent they do? Extensive pollution and resource depletion are problems unique to humans. Besides specific health and survivability issues resulting from pollution and resource depletion, populations have crashed to the point of extirpation in the past, in part due to societal stress induced by anthropogenic resource depletion. While no other population has achieved the degree of technological complexity that exists today, the underlying, fundamental needs of all societies are the same: clean resources, available in the quantities needed to allow survival. When those resources are at risk, the population is threatened. Proactively addressing this threat is a fundamental policy issue. Instead of seeking specific solutions to individual issues of pollution and resource depletion, this paper aims for a broad view, to understand the underlying forces that drive these two problems. With this understanding would come the insight to design policy to proactively mitigate or ideally stop pollution and resource depletion, and hopefully avoid societal trauma.
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    Groundwater: Hidden Questions, Hidden Answers
    (Journal of Freshwater, 1983) Alexander Jr., E Calvin
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    Holaday Circuits, Inc.: Pollution Prevention Measures for Resilient Communities
    (Resilient Communities Project (RCP), University of Minnesota, 2012) Hill, Alex; Sawyer, Shannon; Olson, Eric; Chmielewski, Autumn
    This project was completed as part of the 2012-2013 Resilient Communities Project (rcp.umn.edu) partnership with the City of Minnetonka. Many businesses and industries in Minnetonka use and discharge a significant amount of water and use large amounts of energy as part of their operations. The goal of this project was to develop education and outreach strategies that help businesses address water and energy conservation, as well as surface water protection, through their operations and site management. Minnetonka project lead and natural resources manager Jo Colleran partnered with students in ESPM 5606: Pollution Prevention: Principles, Technologies, and Practices, and a local business called Holaday Circuits, Inc., to develop a case study based on a life cycle analysis of the business’ water and energy use. The students identified conservation strategies that could improve the company’s bottom line, and used the case study to develop a more general checklist for future business energy audits. A poster summarizing the case study and the checklist are available.
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    Lewis Lake Environmental Assessment
    (2005) Roley, Sarah
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    Marcy-Holmes Neighborhood Environmental Profile.
    (1994) Brown, Jennifer
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    Maximum Application Rates for Land Treatment of Septage
    (Water Resources Research Center, University of Minnesota, 1983-05) Anderson, James L.; Clanton, C.J.; Hansel, M.J.; Machmeier, R.E.
    During 1980, septage was applied in rates of 1120 and 1500 kg of nitrogen per hectare to three different soil textures in an attempt to determine maximum loading rates. These rates resulted in increased concentrations of nitrates in the soil water for a Hubbard loamy Sanci, Waukegan silt loam and Lester clay loam, indicating that the application rates exceeded the maximum rate that the soils could treat. The first year's results indicate that soil type, application rates and soil depth resulted in no significant difference in total Kjeldahl nitrogen, ammonia, fecal streptococcus and fecal coliforms in the soil water samples. Nitrate concentrations, however, were significantly different between the soils, application rates and soil depths. For the Hubbard loamy sand, rainfall had a larger effect on nitrate concentrations and movement within the soil profile than for the Waukegan silt loam or Lester clay 1oam. 0n the Waukegan silt loam and Lester clay loam there was relatively little change in the nitrate concentration in the soil profile during the period when septage was applied twice a week. After the design loading had been applied to the soil and no further applications made, a sharp increase in nitrate concentrations was observed in the soil profile. This probably resulted from changing the anaerobic surface layer to an aerobic condition resulting in nitrification and subsequent movement of nitrates through the profile following a rainfall event. With no additional septage application, the second year's data indicate a significant difference in nitrate-N between soils, application rates, and depths. Generally, the nitrate concentrations in the Hubbard loamy sand and Waukegan silt loam were less than the first year, but the concentrations in the Lester clay loam were higher than the first year. This indicates that nitrification and nitrate movement in the Lester clay loam are slower than the other two soils. Application resulted in a significant increase in the concentration of soil water calcium, magnesium, sodium and potassium during the first year of the study. However, there was no increase in the phosphorus content of the soil water.
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    Pollution of Gravel spawning grounds due to fine sediment
    (1985-06) Parker, Gary; Diplas, Panayiotis
    Laboratory experiments which model poorly sorted gravel-bed streams were conducted to examine certain phenomena associated with these streams. The existence and role of the pavement, sediment transport, the accumulation and retention of fines in the bed, and the effect of the fines accumulation in the stream behavior are the phenomena included in this study. Two flumes were used. The first one operated as a recirculating system. It was 16.75 m long and 0.3 m wide with transparent walls. The narrow width of this channel suppressed any tendencies for the formation of bedforms. The second one operated as a feed system. It was 12 m long and 0.53 m wide with opaque walls. This flume allowed for the development of alternate bars. In total, seven series of experiments were performed. On the average, six experiments were conducted for each series. The first experiment of each series was conducted with a given mixture of bed material in the absence of fines. This mixture constitutes a scaled-down version of a rather typical bed material observed in natural gravel-bed streams. Fine material was introduced into the flume during the subsequent experiments. The amount of fines introduced was progressively increased, while the channel bed gradually changed from gravel to sand. At the end of each series the bed became completely covered with fines. It was found that the pavement is a mobile bed phenomenon, which acts as a regulator that renders all available grain sizes to be of nearly equal mobility. This is accomplished by overrepresenting the percentage of large grains exposed to the flow. Flow visualization provided evidence of a correlation between grain motion and the turbulent bursting phenomena. Field data, obtained from the literature, are used to study the bedload transport in paved gravel-bed streams. The stream examined in this case is Oak Creek, a small gravel-bed stream draining the east slope of the Coast Range, Oregon. The bed material of this stream, is divided into ten ranges of grain size. The concept of a similarity transformation is used as a means of collapsing the individual bedload relations, developed empirically for each of the size ranges, into a single curve. The similarity parameter used here renders the bedload relations of nine out of ten size ranges almost perfectly similar. This parameter incorporates the variation in mobility as well as the hiding ·effects due to the difference in the size of the grains. A bedload relation is then developed which accounts for the effects of sediment grading. The same approach is used also for the data obtained from the present study, supporting the conclusions obtained from the analysis of the Oak Creek data. The mechanics of fines infiltration into the bed is also described. While the fines accumulated into the bed did not affect the water surface slope or the channel depth, the amount of fines in the subpavement and pavement correlated well with the bedload transport rate. A model describing this process is in order. Initially, the fines collect in the immediate substrate, reducing the mobility of the grains in the pavement
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    Reaney Feasibility Study.
    (2002) Berglund, Nina; Chatfield, Nathan; Johnson, Andy; Marohn, Chuck; Martin, Marcus; Millet, Eduardo
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    Response of Nearshore Periphyton in Western Lake Superior to Thermal Additions
    (Water Resources Research Center, University of Minnesota, 1974-10) Drown, D.B.; Odlaug, T.O.; Olson, T.A.
    The intent of this research was to ascertain what effects a temperature increase in the order of 10 degrees to 12 degrees C would have on the near-shore periphyton assemblage of Western Lake Superior. To this end a field station, complete with holding tanks and a hot water source, was constructed on a rock ledge of the Lake Superior shore near Castle Danger, Minnesota. During the summer and fall of 1971 and 1972 periphyton covered rocks from the local area of the lake were placed in the experimental holding tanks where they were exposed to a continuous flow of lake water. In addition, denuded rocks were included as part of a regrowth study. One system provided a flow-through of unheated lake water while in the other the temperature was raised above ambient. Growth patterns were followed under both sets of conditions. Periphyton samples were collected on a weekly basis from the ambient control and heated water tanks and were analyzed for photosynthetic pigment concentration, dray and organic weight and total cell count. A quantitative and qualitative examination of the phyletic distribution of algae from the two systems was emphasized. Some of the more important findings and conclusions were as follows: 1. Diatoms were found to be the most prevalent algal type in both heated and cold water tanks. 2. Normal populations of Lake Superior periphytic diatoms (control), in terms of percent composition of the entire assemblage, were not greatly altered by the temperature increases used during the course of this study. 3. Three of the most common algal genera; Synedra, Navicula, and Achnanthes, showed essentially no difference in maximum growth levels attained in cold or heated water other than the fact that, in heated regrowth samples, peak concentrations were reached in a shorter period of time. 4. Several of the periphytic diatoms common to Lake Superior would continue to survive at temperatures well in excess of normal seasonal maxim. 5. Lake Superior contains genera of non-filamentous green algae which have species capable of adapting to extremely high ambient water temperatures. 6. The warm water system was more favorable to green filamentous algae, such as Mougeotia and Zygnema, than was the cold water system. 7. A prevalent green alga found in Lake Superior, Ulothrix zonata, was inhibited by the warmer water conditions. 8. In general, green algae common to Lake Superior are favored by temperatures in excess of those normally found in the lake. 9. Under conditions of these experiments blue-green algae did not increase as a result of thermal addition. 10. Analysis of pheo-pigments indicated that a substantial amount of “apparent” chlorophyll a was actually pheophytin a, a degradation product. Hence, the pheophytin analysis is important to any study dealing with the chlorophyll content of periphyton. 11. Concentrations of pheo-pigments were higher in the cold water tank than in the warm water system. 12. Supplementary observations have suggested that a separate invertebrate community occupied each of the tanks. While the above findings and conclusions indicate that a great deal more needs to be learned of the effects of thermal additions on Lake Superior, this study has pointed out that, if near-shore areas of the lake were warmed to the extent that could occur as the result of a thermal-electric generating station discharge, changes in the phyletic composition of the local periphyton community could be expected. The very nature of a change from diatoms to greens could have serious repercussions on benthic grazers and indeed the entire foodweb of the affected area.
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    Survey of Attitudes Towards the Mississippi River as a Total Resource in Minnesota
    (Water Resources Research Center, University of Minnesota, 1972-09) Baron, Norman J.; Cecil, E. James; Ludwig, James P.; Tideman, Philip L.
    A survey of the attitudes of Minnesotans toward the use, maintenance and development of the Mississippi River in Minnesota was conducted. Background information on the diverse physical nature of the project Universe (those 23 Minnesota counties which the River flows through or is adjacent to) was collected covering the topics of waterflow, soils, population change, changing riparian land use, and recreational opportunities. Great physical and cultural diversity was found in the project Universe. Attitudes of residents were measured by a 40 item mail questionnaire sent to 5,000 residents of the project Universe; 101 in-depth interviews were also conducted. Respondents provided data on their characteristics, evaluated the desirable and undesirable characteristics of the River, evaluated the role of media in providing them with environmental information, expressed attitudes toward the use of the River, how River pollution should be controlled and financed, and provided data on what aspects of their life styles they were and were not willing to change to improve environmental quality. Secondary students were also surveyed in a separate effort to quantify significant difference of attitudes held by youth and adults. Two significant findings were that Minnesotans do not desire to curtail their uses of energy to improve environmental quality, and the perceived present uses of the River are exactly opposite to the uses the public desires.
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    Triclosan, Chlorinated Triclosan Derivative, and Dioxin Levels in Minnesota Lakes
    (2013-12-02) Anger, Cale T; Sueper, Charles; Blumentritt, Dylan J; Mcneill, Kristopher; Engstrom, Daniel R; Arnold, William A; arnol032@umn.edu; Arnold, William A
    The data were collected and generated during the period of 2010-2012 by collecting sediment cores from lakes in Minnesota, dating the years the sediment was deposited as a function of depth, and extracting sections of the cores with solvent to determine the levels of triclosan (TCS), chlorinated triclosan derivatives (CTD), and dioxins in the sediment (PCDD). Dating was performed at the St. Croix Watershed Research Station, triclosan and chlorinated triclosan derivative measurements at the University of Minnesota Department of Civil Engineering, and dioxin analysis by Pace Analytical. The data consists of eight Excel files that include the following tabs 1) accumulation rate and focus corrected accumulation rate of the target contaminants as function of time (FF_Flux), 2) the concentrations of the target contaminants and function of time, 3) the calibration curves of the instruments for triclosan and chlorinated triclosan derivatives, and 4) various statistical analyses (ANOVA). Note that the further back in time, the deeper the sediment that the sample was derived from.
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    West Side Community Environmental Inventory.
    (1997) Brekken, Christy Anderson