Physical Sciences and Mathematics Commons^™

Fish Assemblage Structure In Great Lakes Coastal Wetlands Over Ten Years, Matthew S. Silverhart

Masters Theses

Coastal wetlands in the Laurentian Great Lakes are important habitats for many fish species. The geographic scale of the watershed and the diversity of land uses in the region result in substantial environmental variation among coastal wetlands. During 2011-2020, annual surveys were conducted as part of the Great Lakes Coastal Wetland Monitoring Program (GLCWMP) to better understand the status and trends of coastal wetlands. Fish sampling consisted of fyke netting in monodominant vegetation zones. During this time, 1225 unique monodominant plant zones in coastal wetlands were sampled, resulting in 584,125 fishes captured that consisted of 113 different species. Yellow Perch …

Running Out Of Oxygen: Revealing The Interannual And Intra-Annual Dynamics Of Bottom Water Hypoxia In A Great Lakes Estuary Using Time-Series Observations, Experiments, And Analyses, Nate M. Dugener

Masters Theses

Bottom water hypoxia, a condition of low dissolved oxygen in the bottom waters, negatively effects lakes and freshwater and marine coastal estuaries globally. As climate change shifts climatological and ecological patterns, hypoxia continues to shift in duration and severity. In Muskegon Lake, Michigan, hypoxia occurs annually, restricting fish habitat, increasing cyanobacteria blooms, and disrupting ecological and socioeconomic prosperity. In the current study, we examined the duration and severity of hypoxia over a 11 years (2011-2021) utilizing data from the Muskegon Lake Observatory buoy (MLO, https://www.gvsu.edu/wri/buoy/). During 2021, we analyzed the dissolved oxygen (DO) concentrations observed by the MLO, conducted biweekly …

Coastal Groundwater Catchments Of The Gulf Of Alaska, Aeon Russo

Masters Theses

High latitude mountain environments are experiencing disproportionately adverse effects in a currently changing climate. The Gulf of Alaska (GoA) region is an exemplar of this. Dramatic shifts are occurring in the region’s freshwater reservoirs as glaciers retreat more with each passing year. Research in the region places much focus on observing and predicting climate driven shifts in glacier mass balance, surface discharge, and associated nutrient fluxes to the ocean. On the other hand, coastal groundwater discharge (CGD) is given very little attention. Global and near-global estimates of CGD indicate variable results spanning an order of magnitude. Focusing on regionally specific …

Hydrologic Structure And Function Of Vernal Pools In South Deerfield, Massachusetts, Charlotte Axthelm

Masters Theses

Vernal pools are small, ephemeral wetlands lacking an inlet or outlet. These wetlands, also known as seasonal pools, are found in a wide range of biomes, and their characteristics vary based on location. While the vegetation of western U.S. pools, and amphibians of eastern U.S. pools have been extensively studied, many aspects of vernal pools have not been fully characterized. In particular, although the general seasonal wetting and drying cycle is understood qualitatively, few studies have attempted to quantify the hydrological regime of vernal pools in New England. As water level variation drives many, if not all, of the characteristics …

Impact Of Temperature Increase On Freshwater Fish Species: Energetics And Muscle Mechanics Of Two Centrarchids, Israt Jahan

Masters Theses

Fishes have evolved physiologically to live within a specific range of environmental variation and existence outside of that range can be stressful or fatal. These ranges can coincide for fishes that evolved in similar habitats. This study investigates physiological processes limiting thermal tolerance, specifically how changes in water temperature affect the swimming energetics and muscle mechanics in largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus). I focused on the impact of temperature change at the muscle level in these two species and the capacity to adapt to rapid changes in the environment. Fish were housed at …

Juvenile River Herring In Freshwater Lakes: Sampling Approaches For Evaluating Growth And Survival, Matthew T. Devine

Masters Theses

River herring, collectively alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis), have experienced substantial population declines over the past five decades due in large part to overfishing, combined with other sources of mortality, and disrupted access to critical freshwater spawning habitats. Anadromous river herring populations are currently assessed by counting adults in rivers during upstream spawning migrations, but no field-based assessment methods exist for estimating juvenile densities in freshwater nursery habitats. Counts of 4-year-old migrating adults are variable and prevent understanding about how mortality acts on different life stages prior to returning to spawn (e.g., juveniles …

Determining Sources Of Nitrate In The Semi-Arid Rio Grande Using Nitrogen And Oxygen Isotopes, Diego Alberto Sanchez Hernandez

Masters Theses

The Rio Grande, a semi-arid river in the American Southwest, is a major source of surface water for agriculture and drinking supplies in New Mexico and Texas. In addition to increasing salinity, considerable increases of NO₃^- [nitrate] have been observed in the semi-arid portion of the Rio Grande. It is possible that elevated water salinity inhibits denitrification on irrigated fields and, thus, fails to mediate excess nutrient load from anthropogenic activities. Therefore, two major goals of this project were to 1) characterize and quantify major NO₃^- sources, and 2) assess whether elevated water salinity affects microbial …

Ecological Consequences Of Lost Anadromous Forage Fish In Freshwater Ecosystems, Steven R. Mattocks

Masters Theses

Beginning in the early 1600s, dam construction in New England obstructed anadromous fish access to spawning grounds during migration. As a result, anadromous forage fish populations have declined, which has impacted freshwater, marine, and terrestrial ecosystems. To determine the impacts of dams on anadromous forage fish and freshwater ecosystems, I used historical and current data to estimate population changes in alewives (Alosa pseudoharengus) from 1600-1900. A significant reduction in spawning habitat occurred in New England as a result of 1,642 dams constructed between 1600 and 1900, resulting in 14.8% and 16.6% lake and stream habitat remaining by 1900, …

Using Digital Elevation Models Derived From Airborne Lidar And Other Remote Sensing Data To Model Channel Networks And Estimate Fluvial Geomorphological Metrics, Noah Slovin

Masters Theses

Recent advances in remote-sensing technologies and analysis methods, specifically airborne-LiDAR elevation data and corresponding geographical information system (GIS) tools, present new opportunities for automated and rapid fluvial geomorphic (FGM) assessments that can cover entire watersheds. In this thesis, semi-automated GIS tools are used to extract channel centerlines and bankfull width values from digital elevation models (DEM) for five New England watersheds. For each study site, four centerlines are mapped. LiDAR and NED lines are delineated using ArcGIS spatial analyst tools with high-resolution (1-m to 2-m) LiDAR DEMs or USGS National Elevation Dataset (NED) DEMs, respectively. Resampled LiDAR decreases LiDAR DEM …

Aquatic Habitat Mapping Within The Obed Wild And Scenic River For Threatened And Endangered Species Habitat Delineation, Joseph Ross Candlish

Masters Theses

There is a need to define a more efficient and accurate approach to aquatic habitat mapping. Traditional approaches have focused on intense biological/non-biological sampling and observation analysis within specific and restrained scales. Therefore, an underwater video mapping system (UVMS) has been developed in efforts to identify federally protected aquatic species’ habitats within the Obed Wild and Scenic River (OBRI). The UVMS kayak apparatus provides georeferenced video footage correlated with GPS (global positioning systems) for GIS (geographic information systems) mapping applications. Based on its fluvial and geomorphological trends, OBRI was dissected quantitatively and integrated into databases for species-specific GIS habitat queries. …

The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin

Masters Theses

Dam construction by beavers creates wetlands which have the potential to improve water quality, especially in areas near urban centers. However, beaver dams may also cause flooding problems which can result in the removal of the beaver(s) and the destruction of their dam. A further understanding of how beaver-created wetlands affect water quality will provide additional data which can be utilized in beaver management decisions.

In this study, 41 chemical parameters were examined from water taken above and below beaver-created wetlands that existed in DuPage County, Illinois between May and September 1991. This study was designed to examine the effects …

Sediment Oxygen Demand In Streams Receiving Sewage Effluent, John J. Schultz

Masters Theses

Sediment oxygen demand is an important factor in determining dissolved oxygen concentrations in streams and rivers subjected to sewage effluents and other sources of organic pollution. Resuspension of sediments during bottom-scouring after periods of heavy precipitation exerts an immediate and increased oxygen demand on the water and is expected to decrease sediment oxygen demand at the site.

Sediment samples were collected monthly from April through November, 1983 from three small streams subjected to sources of organic pollution. The samples collected were arbitrarily categorized into wet and dry period samples based on the total precipitation between collection dates. Sediment oxygen demand …

Raw Water Quality In The New Charleston, Illinois Pump Storage Reservoir, Kevin G. Lookis

Masters Theses

Charleston, Illinois, a city located in east-central Illinois, recently implemented a new concept in a raw water system. Due to storage capacity-sedimentation problems in the old Lake Charleston-Embarras River raw water supply, the Charleston Pump Storage Reservoir was constructed. The new system involved building a dike separating the Lake Charleston impoundment from the Embarras River. Water to increase the storage capacity of the reservoir can now be selectively pumped into the impoundment from the river.

Raw water quality in the reservoir was monitored on a weekly basis for a full year from August, 1981 to August, 1982. The levels of …

Water Quality And Benthos Of A Small East Central Illinois Stream, With A Selected Literature Review, Kenneth Lloyd Brummett

Masters Theses

Polecat Creek is an occasionally intermittent stream which drains approximately 18,368 acres in eastern Coles County, Illinois. It travels 15.2 miles through cropland and a partially wooded valley before it enters the Embarrass River 3 miles upstream from Lake Charleston. The stream ranges from 0.5 foot to 5 feet deep at a normal water level, with an average depth of 16 inches. It averages 12 feet wide, with a range from 4 to 20 feet.

A water quality study with 5 stations along the stream was conducted from January 1971 to July 1971. A qualitative benthos study at the same …

Range And Optimum Growth Concentrations Of Phosphate And Nitrate For Chlamydomonas Reinhardtii, Thomas E. Hill

Masters Theses

A study was conducted on the alga Chlamydomonas reinhardtii to determine the range and optimum growth concentrations of phosphate and nitrate. There are only a few species of algae for which this type of data is known. Inorganic nutritional data is basic to the understanding of the complexities of phytoplankton ecology and eutrophication.

The "plus" strain of this heterothallic alga was cultured in a TRIS-buffered inorganic medium with various concentrations of sodium phosphate and potassium nitrate and adjusted to a pH of 7.4. The axenic cultures were evaluated at the end of 6 days with a spectrophotometer, at a wavelength …