Physical Sciences and Mathematics Commons^™

Wind Effects On Near- And Midfield Mixing In Tidally Pulsed River Plumes, Preston Spicer, Kelly L. Cole, Kimberly Huguenard, Daniel G. Macdonald, Michael M. Whitney

Civil Engineering Faculty Scholarship

River plumes transport and mix land-based tracers into the ocean. In tidally pulsed river plumes, wind effects have long been considered negligible in modulating interfacial mixing in the energetic nearfield region. This research tests the influence of variable, realistic winds on mixing in the interior plume. A numerical model of the Merrimack River plume-shelf system is utilized, with an application of the salinity variance approach employed to identify spatial and temporal variation in advection, straining, and dissipation (mixing) of vertical salinity variance (stratification). Results indicate that moderate wind stresses (∼0.5 Pa) with a northward component countering the downcoast rotation of …

Freshwater Composition And Connectivity Of The Connecticut River Plume During Ambient Flood Tides, Michael M. Whitney, Yan Jia, Kelly L. Cole, Daniel G. Macdonald, Kimberly D. Huguenard

Civil Engineering Faculty Scholarship

The Connecticut River plume interacts with the strong tidal currents of the ambient receiving waters in eastern Long Island Sound. The plume formed during ambient flood tides is studied as an example of tidal river plumes entering into energetic ambient tidal environments in estuaries or continental shelves. Conservative passive freshwater tracers within a high-resolution nested hydrodynamic model are applied to determine how source waters from different parts of the tidal cycle contribute to plume composition and interact with bounding plume fronts. The connection to source waters can be cut off only under low-discharge conditions, when tides reverse surface flow through …

Assessing The Factors That Alter Ecological Responses Of Cold, Oligotrophic Lakes To Nutrient Subsidies, Benjamin Burpee

Electronic Theses and Dissertations

Arctic and alpine areas experience rapid environmental changes that are altering nutrient delivery to lakes. I review the current state of lake ecosystem subsidization research and summarize Arctic and alpine lake subsidies, their ecological importance, and ways they are changing. I identify current knowledge gaps in Arctic and alpine lake subsidization research and highlight the importance of Arctic and alpine lakes for ecosystem subsidy research. Meltwater from the Greenland Ice Sheet (GrIS) exports sediment and nutrients to lakes, but the ecological effects of this subsidy remain unclear. To assess the effects, four glacially fed (GF) lakes that receive GrIS meltwater …

Improved Estimates Of Tributary Nitrogen Load To Casco Bay, Maine, Whitley J. Gray

Electronic Theses and Dissertations

Over the past two decades, total nitrogen (TN) concentrations have increased in Casco Bay (CBEP 2015). The sources of the increased nitrogen are poorly understood but occur with simultaneous population growth and land use changes. The total riverine nitrogen load to Casco Bay was previously estimated by Liebman and Milstead (2012) using the United States Geologic Survey’s (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model. The SPARROW model uses watershed characteristics, regional monitoring data and nitrogen source data to estimate nitrogen loading but was not validated using measurements of nitrogen in the Casco Bay watershed. This study attempts to …

Three-Dimensional Bedrock Channel Evolution With Smoothed Particle Hydrodynamics, Nick Richmond

Electronic Theses and Dissertations

Bedrock channels are responsible for balancing and communicating tectonic and climatic signals across landscapes, but it is difficult and dangerous to observe and measure the flows responsible for removing weakly-attached blocks of bedrock from the channel boundary. Consequently, quantitative descriptions of the dynamics of bedrock removal are scarce. Detailed numerical simulation of violent flows in three dimensions has been historically challenging due to technological limitations, but advances in computational fluid dynamics aided by high-performance computing have made it practical to generate approximate solutions to the governing equations of fluid dynamics. From these numerical solutions we gain detailed knowledge of the …

Physical And Chemical Response Of Small, North Temperate Lakes To Recovery From Acidification And Climate Change, Amanda Gavin

Electronic Theses and Dissertations

As the rate of sulfate (SO42-) deposition continues to decline and climate is trending towards warmer and wetter conditions, the biogeochemical and physical response of small, north temperate lakes is variable. In this study, we observed long-term chemical trends combined with seasonal water temperature patterns in the context of climate change and recovery from acidification in two remote lake populations in Maine: 29 high elevation lakes and eight low elevation lakes. Small, temperate lakes are the most abundant type of lake, making them a widely representative study sample to consider. Maine’s high elevation lakes (>600m) could potentially provide unique …

Evaluating Potential For Water Quality Decline In Maine Lakes, Kaci N. Fitzgibbon

Electronic Theses and Dissertations

Understanding lake vulnerability with respect to eutrophication and loss of water quality is important for sustainability of aquatic ecosystems. This project aims at identifying and quantifying the effects of relevant physiochemical, climate, and watershed characteristics on lake vulnerability in order to develop management decision tools for the Maine Department of Environmental Protection (MEDEP). In a changing chemical and physical environment, using independent variables from each of these categories and then relating them to the summer lake epilimnetic phosphorus (P) concentrations allows for development of models to inform stakeholders of lake vulnerability to eutrophication problems.

We studied 24 lakes covering a …

Using Hydroacoustics To Investigate Biological Responses In Fish Abundance To Restoration Efforts In The Penobscot River, Maine, Constantin C. Scherelis

Electronic Theses and Dissertations

Spatiotemporal advantages linked to hydroacoustic sampling techniques have caused a surge in the use of these techniques for fisheries monitoring studies applied over long periods of time in marine systems. Dynamic physical conditions such as tidal height, boat traffic, floating debris, and suspended particle concentrations result in unwanted noise signatures that vary in intensity and location within a hydroacoustic beam over time and can be mixed with the acoustic returns from intended targets (e.g., fish). Typical processing filters applied over long term datasets to minimize noise and maximize signals do not address spatiotemporal fluctuations of noise in dynamic systems. We …

Tb207: A Manual For Remote Sensing Of Maine Lake Clarity, Ian M. Mccullough, Cynthia S. Loftin, Steven A. Sader

Technical Bulletins

The purpose of this manual is to support use of satellite-based remote sensing for statewide lake water-quality monitoring in Maine. The authors describe step-by-step methods that combine Landsat and MODIS satellite data with field-collected Secchi disk data for statewide assessment of lake water clarity. Landsat can be simul­taneously used to assess more than Maine 1,000 lakes ≥ 8 ha, whereas MODIS can be used to assess a maximum of 364 lakes ≥ 100 ha (250-m image resolution) or 83 lakes ≥ 400 ha (500-m image resolution). Although the methods were specifically developed for Maine, other states or non-Maine agen­cies may …

Collaborative Research: Globec Pan Regional Synthesis: The Effect Of Varying Freshwater Inputs On Regional Ecosystems In The North Atlantic, Fei Chai

University of Maine Office of Research Administration: Grant Reports

This research addresses several mechanisms by which freshwater influx might impact the primary production of Calanus finmarchicus in the northern North Atlantic Ocean. Variability in the winter North Atlantic Oscillation index is related to changes in various physical and biological parameters across the entire North Atlantic, but the mechanisms underlying those relationships are not well known. Understanding basin-to-regional connections is important for interpreting patterns of variability observed on both sides of the Atlantic during the core GLOBEC study period (1993-1999) and from earlier observations, and inferring process, whether local or remote, from those observed patterns. The proposed research is focused …

Collaborative Research: The Response Of Lakes To Disturbance And Climate Change: Calibrating Sedimentary Records To Test The Landscape Position Concept, Jasmine E. Saros

University of Maine Office of Research Administration: Grant Reports

Landscape disturbance and climate change affect lakes in proportion to their contact with ground water, sometimes resulting in different responses in neighboring lakes. This project develops methods for reconstructing past water chemistry and food webs of lakes. The biological and chemical deposits in surface sediment samples will be compared with the water in 62 modern lakes. The resulting relationships will be tested by comparing sediment cores with 24 years of observations from the North Temperate Lakes Long Term Ecological Research (NTL-LTER) site. The methods will then be used to reconstruct 150 years of history for several lakes, adding perspective to …

Tb202: Composition And Biomass Of Forest Floor Vegetation In Experimentally Acidified Paired Watersheds At The Bear Brook Watershed In Maine, Peter Kenlan, G. B. Wiersma, A. S. White, I. J. Fernandez

Technical Bulletins

The percentage cover (abundance), frequency of occurrence, biomass, species richness, and species diversity of understory herbs was measured on a paired watershed ecosystem in eastern Maine, USA. This paired watershed site (Bear Brook Watershed in Maine, BBWM) has had the West Bear Brook Watershed treated bi-monthly with granular ammonium sulfate at a rate of 28.8 kg S ha-1 yr-1 and 25.2 kg N ha-1 yr-1 since 1989. East Bear Brook Watershed serves as the reference site. More than 100 plots were randomly located across the two watersheds. The data suggest that there is generally a lower frequency of occurrence of …

Effects Of Fish Introductions On The Geographic Distribution And Native Invertebrate Biodiversity Of Naturally Fishless Lakes In Maine, Emily Gaenzle Schilling

Electronic Theses and Dissertations

Widespread fish stocking has led to a worldwide decline in naturally fishless lakes and their associated communities. Little is known about the historical distribution or native communities of these freshwater ecosystems. The objectives of this study were to: 1) develop a quantitative method to remotely detect naturally fishless lakes in Maine, 2) conduct a landscape-scale assessment of unique attributes of fishless lake macroinvertebrate communities, 3) identify macroinvertebrate bioindicators of fish absence, and 4) assess effects of introduced fish on native macroinvertebrates. I identified two physiographic types of naturally fishless lakes in Maine: kettle lakes in the eastern lowlands and foothills …

A Paleolimnological Assessment Of Three Oligotrophic Watersheds In Maine, Tiffany Ann Wilson

Electronic Theses and Dissertations

Phosphorus (P) is a limiting nutrient in aquatic ecosystems. Its bioavailability determines the trophic status of lakes. The biogeochemistry of P in surface waters can be controlled by a combination of abiotic and biotic factors. Dissolved inorganic aluminum (Al) and iron (Fe) hydrolyze in streams and lakes to produce Al(OH)₃ and Fe(OH)₃ in the water column. These hydroxides may also form through photo-oxidation of complexes with DOC, liberation of inorganic metal species, and precipitation, followed by sedimentation. These solid phases readily adsorb P from the water column, reducing the amount that is available for biological nutrition (Kopácek et …

Tb196: Temperature, Soil Moisture, And Streamflow At The Bear Brook Watershed In Maine (Bbwm), Ivan J. Fernandez, Joseph E. Karem, Stephen A. Norton, Lindsey E. Rustad

Technical Bulletins

The Bear Brook Watershed in Maine is a whole-ecosystem chemical manipulation initiated in 1987 to study the effects of acid deposition on forests and surface waters. The focus of this research was to understand the biogeochemical response of watersheds with emphasis on chemistry and hydrology. In 2001 a program was initiated to provide more detailed measurements of temperature and moisture to examine critical linkages amongst chemical, biological, and physical processes that ultimately work together to define ecosystem function. The purpose of this publication is to provide data from the initial phase of soil temperature, air temperature, and soil moisture measurements …

Lake-Level Influences On Chironomid-Based Reconstructions Of Paleotemperature, Ann Dieffenbacher-Krall

University of Maine Office of Research Administration: Grant Reports

This award is for support of a study to determine the influence of lake-level changes on chironomid-based temperature estimates. A transect of cores from within each of two lakes in northern Maine will be examined for evidence of past water levels. Chironomid analysis will be performed on cores from both lakes. Geologic/chronologic evidence of Younger Dryas-age ice readvance in northern Maine will provide the data necessary to apply a well-developed glaciological model to determine the range of temperature and precipitation that could possibly have prevailed during this period. Chironomid estimates of temperature will be reconciled with the temperature range derived …

Snow Chemistry Across Antarctica, Nancy Bertler, Paul Andrew Mayewski, Alberto Aristarain, P. Barrett, S. Becagli, Ronaldo Torma Bernardo, Xiao Cunde, M. Curran, Qin Dahe, Daniel Dixon, Francisco Adolfo Ferron, H. Fischer, Markus Frey, M. Frezzotti, F. Fundel, Christophe Genthon, R. Gragani, Gordon Hamilton, M. Handley, Sungmin Hong, E. Isaksson, Ren Jiawen, Kokichi Kamiyama, Satoru Kanamori, Eija Karkas, L. Karlöf, S. Kaspari, K. Kreutz, A. Kurbatov, E. Meyerson, Hideaki Motoyama, R. Mulvaney, Zhang Mingjun, H. Oerter, E. Osterberg, M. Proposito, A. Pyne, U. Ruth, Jefferson Cardia Simoes, B. Smith, S. Sneed, Kimmo Teinila, F. Traufetter, R. Udisti, Aki Virkkula, Okitsugu Watanabe, B. Williamson, E. Wolff, Li Zhongqin

Earth Science Faculty Scholarship

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO₃, SO₄) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve …

Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham

Electronic Theses and Dissertations

In order to maintain pond-breeding amphibian species richness, it is important to understand how both natural and anthropogenic disturbances affect species assemblages and individual species distributions both at the scale of individual ponds and at a larger landscape scale. The goal of this project was to investigate what characteristics of ponds and the surrounding wetland landscape were most effective in predicting pond-breeding species richness and the individual occurrence of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana) and pickerel frog (Rana palustris) breeding sites in a beaver-modified landscape and how this landscape has changed over …

A Comparison Of The Ecological Integrity Of Headwater Streams Draining Harvested And Un-Harvested Watersheds In The Western Mountains Of Maine, U.S.A., Darlene Siegel

Electronic Theses and Dissertations

Physical, chemical, and biological characteristics of four headwater streams draining forested watersheds were compared to determine the effectiveness of Riparian Management Zones (RMZs) in protecting aquatic ecological integrity from the effects of forest harvesting. Two of the watersheds were harvested with a 30% sheltenvood cut and a 75 foot buffer was left adjacent to the streams. The other two watersheds were un-harvested and were used as reference conditions for comparison with the harvested watersheds. General environmental conditions in these four headwater streams during the study period were characterized as follows. Each stream was located within a mixed- wood forest dominated …

Effects Of Nitrogen Deposition And Flow Permanence On Stream Organic Matter Dynamics, Michael Andrew Joseph Chadwick

Electronic Theses and Dissertations

The objective of this study was to investigate the effects of N enrichment and flow permanence on stream organic matter dynamics at the Bear Brook Watershed in Maine (BBWM). BBWM is a paired-catchment manipulation of atmospheric (NH₄)₂SO₄ deposition, and the goal of the experiment is to understand how increased N affects forested catchments. The treatment has increased stream nitrate and foliar N concentrations in the treatment watershed. Because streams draining BBWM are intermittent, this investigation provided an opportunity to investigate the combined effects of stream flow permanence and human alteration of N cycling in a …

Effects Of Roadway-Related Physical And Chemical Habitat Alterations On Stream Ecosystems, Thomas Stuart Woodcock

Electronic Theses and Dissertations

Roadways are an important feature of both rural and urban landscapes, and disturbances associated with them have a variety of effects on stream ecosystems. Organisms may be differentially affected by toxic substances, depending on such factors as sediment and water chemistry, toxin bioavailability, uptake and elimination processes, and tolerance mechanisms. The effects of heavy metal pollution and habitat alteration related to urbanization and industry were examined along a gradient of impact in Goosefare Brook, a small stream in southern Maine with a history of water quality impahlent. The structure of invertebrate assemblages changed significantly along the gradient, and were related …

Arsenic In Drinking Water And Public Opinion On Wildlife Management As Case Studies Illustrating Natural Resource Policy, Jessica Sargent-Michaud

Electronic Theses and Dissertations

There are various ways to approach policy planning. This thesis consists of two Maine natural resource issue case studies illustrating different approaches to policy analysis. The first, a case study of arsenic contamination, is an example of a study that assembles information and provides that information to the public to influence public behavior. The second, a case study of wildlife management, is an example of a study that surveys the public to collect information on the public's opinions and attitudes to influence agency behavior towards the public. Arsenic in drinking water in Maine is a public health concern. There may …

Relationships Between Stream Geomorphology And Fish Community Structure And Diversity In Maine, Emily Gaenzle

Electronic Theses and Dissertations

Predicting patterns in species distribution and abundance for resource management and conservation is a major focus of applied ecology. The primary objective of this study was to determine if there is a predictable relationship between stream geomorphology and fish community structure, native species richness, and native salmonid abundance in Maine. Specifically, I examined relationships between fish assemblages and geomorphic stream types, as delineated by the Rosgen classification system (Rosgen 1996). Fifty-three stream reaches in Maine were classified, and fish communities within the reaches were characterized using backpack electrofishing. Species richness was lowest in A-type streams (i.e., steep, entrenched, confined), which …

Determining Atmospheric Deposition Inputs To Two Small Watersheds At Acadia National Park, Sarah J. Nelson

Electronic Theses and Dissertations

Two small upland watersheds have been gauged and monitored at Acadia National Park since 1998. Cadillac Brook watershed burned in a wildfire in 1947. Hadlock Brook watershed has been undisturbed for several centuries, and serves as the reference site. Precipitation and throughfall volume and chemistry data have been collected using wetonly and continuously open collectors. Hydrologic and chemical inputs to the sites have been determined for each site. Differences in watershed and vegetation characteristics control the input of water and major ions to these watersheds. Vegetation type was the dominant control on enhancement of precipitation across the heterogeneous watersheds. Relative …

Dickey-Lincoln School Lakes Project Economic Analysis Study, New England Division, United States Army Engineer Division, Acres American Incorporated

Dickey-Lincoln School Lakes Project

The purpose of this study was to perform an economic assessment of the Dickey-Lincoln School Lakes Project. This was accomplished by simulating the New England electrical supply system with and without the project and making a comparison of the resultant production costs.

Dickey-Lincoln School Lakes Project At Dickey, Maine : Final Environmental Impact Statement, New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

The Final Impact Statement is supported by all appendices from all drafts as well as supplementary information provided in Supplements to those Appendices. It comprises three volumes. Volume I is the statement volume. Volume II consists of two parts. Part I contains the comment and response portion of Section 9 for the 1977 Draft EIS. Part II contains comments and responses on the 1978 Revised Draft EIS, in addition to reproductions of the original comment letters received on the Draft Fish and Wildlife Mitigation Report and responses to these comments. Volume III, Part I contains reproductions of the original comment …

Dickey-Lincoln School Lakes Transmission Project: Final Environmental Impact Statement: Appendix L, New England Division, United States Army Corps Of Engineers, United States Department Of Energy

Dickey-Lincoln School Lakes Project

This draft EIS Supplement describes the environmental impacts of updated transmission plans of the Department of Energy (DOE) for the proposed Dickey-Lincoln School Lakes Project. Energy produced by the project is to be integrated into the New England electric system if the project is constructed.

Dickey-Lincoln School Lakes Project At Dickey, Maine : Final Environmental Statement, New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

This document contains those comments and responses on the Revised Draft Environmental Impact Statement. It is a continuation of Volume II published by the Corps in 1978. In addition, it contains reproductions of those letters of comment received on the March 1980 Draft Fish and Wildlife Mitigation Plan, and the responses to these comments.

Dickey-Lincoln School Lakes Project At Dickey, Maine : Final Environmental Statement, Volume 1-4, U. S. Army Engineer Division, New England

Dickey-Lincoln School Lakes Project

The proposed Dickey-Lincoln School Lakes Project in northern Maine is a multipurpose installation on the St.John River. The combination hydroelectric power and flood control project is located in Aroostook County, Maine, near the Canadian border. The two proposed earth fill dams located at Dickey are 10,200 feet in length with a maximum height of 335 feet. They would impound 7.7 million acre feet of water at a maximum pool elevation 910 feet mean sea level. A second earth filled dam located 11 miles downstream at Lincoln School would serve as a regulatory dam. It would be 2100 feet in lenqth, …

Federal Water Pollution Control Act Section "404" Evaluation For Dickey-Lincoln School Lakes, New England Division, United States Army Engineer Division, United States Army Corps Of Engineers

Dickey-Lincoln School Lakes Project

The purpose of this report is to relate various aspects of the proposed Dickey-Lincoln School Lakes Hydroelectric Project to appropriate considerations defined by Section 404 of the Federal Water Pollution Control Act of 1972.