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Full-Text Articles in Physical Sciences and Mathematics

Fish Assemblage Structure In Great Lakes Coastal Wetlands Over Ten Years, Matthew S. Silverhart Jan 2024

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 …


Tree-Ring Reconstruction Of Ouachita River Streamflow, Keaton Cade Jenkins-Joyce Dec 2023

Tree-Ring Reconstruction Of Ouachita River Streamflow, Keaton Cade Jenkins-Joyce

Graduate Theses and Dissertations

The Ouachita River drains the Ouachita Mountains and Upper Coastal Plain in Arkansas and Louisiana. The Ouachita River is used for navigation, power generation, recreation, water supply, and wastewater treatment. The river has been prone to low flows during drought and extreme flooding, which were principal justifications for the construction of three large multipurpose dams on the stream. It is likely that the use of the Ouachita River will be stressed by future population growth, economic expansion, and climate change. For this study, tree-ring chronologies from various locations in and near the Ouachita River drainage basin were used to reconstruct …


Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton Dec 2023

Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton

Graduate Theses and Dissertations

Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need …


Stream Restoration Effectiveness In Mullins Creek In Fayetteville, Arkansas, Amadeo Scott Dec 2023

Stream Restoration Effectiveness In Mullins Creek In Fayetteville, Arkansas, Amadeo Scott

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Lotic waterways are vital for habitat, food, water, and flood protection, but urbanization poses a major threat to their integrity. Runoff from urban surfaces leads to pollution, flashiness, loss of biodiversity, and other symptoms, also known as Urban Stream Syndrome (USS). To combat USS, streams can be restored, but most restorations are not monitored so their long-term effectiveness is unknown. This study quantitatively evaluated a decade-old stream restoration in Fayetteville, Arkansas, to assess its effectiveness in combating USS and achieving set restoration goals, and to gain insights for future restoration projects. Restoration goals included decreasing erosion and sedimentation, increasing pool …


Understanding The Flow Dynamics Of The Pearl River, Ms, Through Hydrodynamic Modeling, Nahruma Mehzabeen Pieu Jun 2023

Understanding The Flow Dynamics Of The Pearl River, Ms, Through Hydrodynamic Modeling, Nahruma Mehzabeen Pieu

Master's Theses

The Pearl River brings fresh water and nutrients into Lake Borgne regulating conditions for oyster growth in estuarine waters. However, there are no flow measurement stations installed on East Pearl or West Pearl either at the river outlets or after the upstream bifurcation of the Pearl. This study aims to model the Lower Pearl River to understand the flow dynamics in the major branches, and to determine the final outflow distribution into the Mississippi Sound, aiming to improve river forcing for ocean models studying estuarine dynamics of the Mississippi Sound.

Synthetic meandering bathymetry with updated banks is developed and applied …


From Mountain Streams To Urban Rivers: An Assessment Of Microplastic Sources And Characteristics, Macy Gustavus May 2023

From Mountain Streams To Urban Rivers: An Assessment Of Microplastic Sources And Characteristics, Macy Gustavus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plastic products are produced and discarded at an alarming rate. Bottles, bags, toys, and clothing break down into tiny plastic pieces called microplastics, ranging in size from an eraser on the top of a pencil to smaller in size than a red blood cell. Microplastics are becoming so common in the environment that they travel in the atmosphere, rivers, and ocean currents in ways that are similar to other types of Earth Systems Cycles (i.e., the water cycle). In this study, we explored microplastic sources and sinks in a freshwater river system and how seasonal changes in discharge affect how …


Evaluation Of Hydrogeochemical Characteristics Of San Joaquin, Tulare, And Mojave Aquifers, Southern California, Maedeh Hassanvand May 2023

Evaluation Of Hydrogeochemical Characteristics Of San Joaquin, Tulare, And Mojave Aquifers, Southern California, Maedeh Hassanvand

Graduate Theses and Dissertations

Before making attempts to enhance and manage the quality of water, a thorough understanding of these processes is necessary since the chemical quality of groundwater is impacted by a number of linked processes. This would be more important in arid and semiarid regions like the southern part of California where more rely on groundwater for agriculture and drinking water uses than the other states. As a result, fundamental knowledge of the governing processes of groundwater chemistry is required for effective water resource management. Thus, this study is primarily concerned with three aspects in Mojave, Tulare, and San Joaquin aquifers: The …


Estimating Evapotranspiration And Analyzing Soil Moisture And Heat Flux Parameters At Taneum Creek, Central Washington, Edward Vlasenko Jan 2023

Estimating Evapotranspiration And Analyzing Soil Moisture And Heat Flux Parameters At Taneum Creek, Central Washington, Edward Vlasenko

All Master's Theses

In the past two decades, stream restoration work, primarily in the form of wood emplacement, has been undertaken in the Taneum Creek watershed, resulting in increased channel-floodplain connectivity. One of the goals of stream restoration was to boost dry season groundwater storage in the shallow floodplain aquifer. However, any gains in groundwater due to increased connectivity may be nullified by increased evapotranspiration (ET) losses because of denser floodplain vegetation. Within the floodplain aquifer budget, ET is a major flow of water out of the system and is not well quantified.

In order to quantify ET, a monitoring site was established …


Emerging Red Sore Disease Of American Eel (Anguilla Rostrata) In Chesapeake Bay: Etiology, Epidemiology, And Impacts In Aquaculture And The Wild, Amanpreet Kaur Kohli Jan 2023

Emerging Red Sore Disease Of American Eel (Anguilla Rostrata) In Chesapeake Bay: Etiology, Epidemiology, And Impacts In Aquaculture And The Wild, Amanpreet Kaur Kohli

Dissertations, Theses, and Masters Projects

Emerging infectious diseases in aquatic systems, both in aquaculture and in the wild, are a global concern. Many have proposed an uptick in marine diseases as a result of environmental changes including a warming climate, habitat modifications, trade and transfer of wildlife and aquaculture products, pollution, overharvesting of resources, and other anthropogenic impacts. These perturbations can disturb the delicate host-pathogen relationships and result in new diseases or exacerbate the existing diseases in a population. Diseases can lead to several direct and indirect effects in the ecosystem such as population declines and extinctions, and thereby a change in population dynamics, as …


Evaluating Gizzard Shad Dorosoma Cepedianum And Threadfin Shad D. Petenense Populations In Two Kentucky Reservoirs Recently Invaded With Silver Carp Hypophthalmichthys Molitrix, Nathan Klein Jan 2023

Evaluating Gizzard Shad Dorosoma Cepedianum And Threadfin Shad D. Petenense Populations In Two Kentucky Reservoirs Recently Invaded With Silver Carp Hypophthalmichthys Molitrix, Nathan Klein

Murray State Theses and Dissertations

Gizzard Shad Dorosoma cepedianum and Threadfin Shad D. petenense are ecologically important fish species found in many reservoirs throughout the southeastern United States, such as Kentucky Lake and Lake Barkley. One current challenge that Gizzard Shad and Threadfin Shad may face in these two reservoirs is competition with the invasive Silver Carp Hypophthalmichthys molitrix. However, quantifying the effects of this competition may be difficult because of limited baseline population data for Gizzard Shad and Threadfin Shad in these two reservoirs. Gizzard Shad and Threadfin Shad were collected by boat electrofishing and surface trawling in cove and main channel locations …


Assessment Of Water Quality Index, Light Attenuation, And Nutrient Sequestering By Submerged Aquatic Vegetation In The Detroit River, John Scannell Jan 2023

Assessment Of Water Quality Index, Light Attenuation, And Nutrient Sequestering By Submerged Aquatic Vegetation In The Detroit River, John Scannell

Electronic Theses and Dissertations

This thesis assessed water quality – submerged aquatic vegetation interactions in the Detroit River. Submerged aquatic vegetation provides essential ecosystem services that support aquatic biodiversity and regulating ecosystem services such as carbon sinks, purifying water and nutrient cycling. Chapter 2 explored how degraded water quality in the Detroit River limits submerged aquatic vegetation via light limitation. A water quality index and light extinction coefficients were measured at 21 sites along with installation of in-situ water quality sondes at 4 sites to measure water quality at high temporal resolution. The river wide median euphotic depth was estimated to be 1.30 m, …


Effects Of Invasive Species On Ohio River Zooplankton, Samuel John Johnston Jan 2023

Effects Of Invasive Species On Ohio River Zooplankton, Samuel John Johnston

Graduate Theses, Dissertations, and Problem Reports

Invasive species have the potential to dramatically change both aquatic and terrestrial ecosystems with rates of introduction only expected to increase across the Globe. In the Mississippi River basin filter feeding silver (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis) collectively known as invasive carp were introduced into aquaculture ponds where they subsequently escaped and spread to interconnected basins. Invasive carp have not yet completely established throughout the entire Ohio River. Managers recognize three distinct phases of carp invasion: establishment front, invasion front and presence front. In the Illinois River invasive carp are very well established and …


Comparison Of Permafrost Thaw-Related Changes To Hydrological Response And Land Cover In Subarctic Peatland-Dominated Landscapes, Mikhail Mack Jan 2023

Comparison Of Permafrost Thaw-Related Changes To Hydrological Response And Land Cover In Subarctic Peatland-Dominated Landscapes, Mikhail Mack

Theses and Dissertations (Comprehensive)

The hydrological implications of discontinuous permafrost thaw in peatland-dominated basins are not well understood. While there is evidence suggesting that permafrost-thaw-driven land cover change increases annual runoff and the runoff ratio in the Taiga Plains of northwestern Canada, few studies have evaluated the impact on small to medium-sized basins (< 105 km2) outside this ecoregion. Here, we assess runoff, runoff ratio, and precipitation trends for 34 peatland-dominated basins, of which 28 are in the discontinuous and sporadic permafrost zones and 6 in adjacent permafrost-free environments. We calculated annual and monthly trends between 1970 and 2016 using the Mann-Kendall …


Tools For Predicting Emulsification Capacity Of Crude Oil Exposed To Sunlight: Impact Of Photoproduced Carboxylic Acids On Emulsion Stability, Chaka Nacaya Brown Dec 2022

Tools For Predicting Emulsification Capacity Of Crude Oil Exposed To Sunlight: Impact Of Photoproduced Carboxylic Acids On Emulsion Stability, Chaka Nacaya Brown

University of New Orleans Theses and Dissertations

The role of acids in the formation of emulsions from sunlight exposed petroleum is not well understood. To elucidate the impact of sunlight on the formation of emulsions from petroleum, Macondo, its surrogate and NIST 1619b and 2717a were separately exposed to simulated sunlight for up to 48 hours as a film dispersed into a quartz dish, or a film spread on water. Emulsion stability was scored from 0-5. All exposures demonstrated a correlation between emulsion stability and sunlight exposure with no observable emulsification in absence of photoproduction due to sunlight exposure. Aqueous studies of DOCHC (dissolved organic carbon …


Fitness Of Interspecific Hybrids In The Genus Cyprinella: An Evaluation Of Swimming Performance In North American Stream Fishes, Jessica Wilks Dec 2022

Fitness Of Interspecific Hybrids In The Genus Cyprinella: An Evaluation Of Swimming Performance In North American Stream Fishes, Jessica Wilks

Biology Theses

Due to anthropogenic pressures, freshwater ecosystems are being rapidly destroyed worldwide. Accordingly, human impacts have also resulted in the loss of native aquatic biodiversity. In particular, the introduction of non-native species to aquatic habitats is of great concern. Historically, the introductions of many non-native freshwater fishes are the result of commercial baitfish aquaculture, food industries, and private aquarium release. The red shiner (Cyprinella lutrensis) is a small stream fish that is endemic to the Central U.S., and its natural range is restricted to East of the Mississippi River. Since the 1950’s, red shiner have been commercially raised and transported …


Life Cycle Assessment Of Novel Electrochemical Struvite Recovery In Municipal Wastewater Treatment At The Plant And U.S. Watershed Scales, Karla Morrissey Dec 2022

Life Cycle Assessment Of Novel Electrochemical Struvite Recovery In Municipal Wastewater Treatment At The Plant And U.S. Watershed Scales, Karla Morrissey

Graduate Theses and Dissertations

As the supply of phosphorus decreases, nutrient recovery in municipal wastewater treatment has become an important area of research. Recovery methods for phosphorus-containing fertilizers, such as struvite, and other products are currently being developed and assessed for their efficiency and economic feasibility. Potential environmental impacts from nutrient recovery are also being assessed as design for the environment is important, especially with regards to the eutrophying potential of phosphorus in phosphorus-limited freshwater aquatic systems. Life cycle assessment (LCA) is a tool that can be used to estimate potential environmental impacts of a product or service focusing on its entire life cycle. …


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 Nov 2022

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 …


Silver Carp Hypopthalmichthys Molitrix Movements In The Lower Tennessee And Lower Cumberland River, Miranda Belanger, Timothy Spier Oct 2022

Silver Carp Hypopthalmichthys Molitrix Movements In The Lower Tennessee And Lower Cumberland River, Miranda Belanger, Timothy Spier

Student Scholarship & Creative Works

Silver Carp Hypophthalmichthys molitrix are an invasive species making up a large portion of the fish biomass in the lower portions of the Tennessee River and the Cumberland River. This species is expanding its range throughout the upper portions of these rivers, beginning with Kentucky Lake and Lake Barkley. Silver Carp rarely spawn in Kentucky Lake and Lake Barkley, but they can enter these reservoirs through the lock chamber. Thus, the bottleneck created by lock chambers can be used to control expansion of invasive Silver Carp. Although Silver Carp movement patterns have been studied in other portions of the Tennessee …


Evaluating Gizzard Shad Dorosoma Cepedianum Populations In Two Kentucky Reservoirs Recently Invaded By Silver Carp Hypophthalmichthys Molitrix, Nathan Klein, Timothy Spier Oct 2022

Evaluating Gizzard Shad Dorosoma Cepedianum Populations In Two Kentucky Reservoirs Recently Invaded By Silver Carp Hypophthalmichthys Molitrix, Nathan Klein, Timothy Spier

Student Scholarship & Creative Works

Gizzard Shad Dorosoma cepedianum are an ecologically important fish species found in many reservoirs throughout the southeastern United States such as Kentucky Lake and Lake Barkley. One current challenge that Gizzard Shad may face in these two reservoirs is competition with the invasive Silver Carp Hypophthalmichthys molitrix. However, quantifying the impacts of this competition may be difficult because of limited baseline population data for Gizzard Shad in these two reservoirs. The objective of this study is to describe size structure, condition, age, growth, mortality, and spawning potential of these two populations. Gizzard Shad were collected by boat electrofishing and …


The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt Aug 2022

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …


Developing A Miniature Smart Boat For Marine Research, Michael Isaac Eirinberg Jun 2022

Developing A Miniature Smart Boat For Marine Research, Michael Isaac Eirinberg

Computer Engineering

This project examines the development of a smart boat which could serve as a possible marine research apparatus. The smart boat consists of a miniature vessel containing a low-cost microcontroller to live stream a camera feed, GPS telemetry, and compass data through its own WiFi access point. The smart boat also has the potential for autonomous navigation. My project captivated the interest of several members of California Polytechnic State University, San Luis Obispo’s (Cal Poly SLO) Marine Science Department faculty, who proposed a variety of fascinating and valuable smart boat applications.


Cyanobacterial Harmful Algal Blooms Vary Within And Across Years At Lake Fayetteville, Arkansas, Alyssa Ferri May 2022

Cyanobacterial Harmful Algal Blooms Vary Within And Across Years At Lake Fayetteville, Arkansas, Alyssa Ferri

Graduate Theses and Dissertations

The occurrence of cyanobacterial harmful algal blooms (HABs) and toxins are a nationwide concern. Although Lake Fayetteville likely experienced HABs for many years, microcystin, an algal toxin, was not monitored until 2019. The objectives of this study were to: 1) observe temporal variation in water quality and total microcystin concentrations, 2) quantify thresholds with microcystin and nutrients, algal parameters, and environmental factors, and 3) evaluate complex relationships between total microcystin and nutrient supplies, algal parameters, and environmental factors using a classification and regression tree model (CART). Three sites (dam, inlet, and mid) at Lake Fayetteville were sampled weekly to monthly …


The Effects Of Water With Anti-Inflammatory Capabilities (Wac) On Circulating Inflammatory Biomarkers At Rest And Following Resistance Exercise, Brittany Martin May 2022

The Effects Of Water With Anti-Inflammatory Capabilities (Wac) On Circulating Inflammatory Biomarkers At Rest And Following Resistance Exercise, Brittany Martin

Health, Human Performance and Recreation Undergraduate Honors Theses

Purpose: To determine the effects of waters with anti-inflammatory capabilities (WAC) influence circulating inflammatory biomarkers at rest and following resistance exercise. Methods: Participants completed a heavy lifting protocol and drank water with anti-inflammatory capabilities for a total of six weeks. Blood samples were taken at different at 9 different time intervals to assess concentrations of anti-inflammatory markers and to quantify inflammatory biomarkers. Those time intervals included pre-AHREP 1 and post-AHREP 1, 24-hr post-AHREP 1, 48-hr post-AHREP 1, 3-week check-up, pre-AHREP 2, post-AHREP 2, 24-hr post-AHREP 2, and 48-hr post-AHREP 2. Background: The biomarkers that were focused on were: IL-6 …


How Flow Regime Affects Predator-Prey Relationships Of Stream Darter And Shiner Species, Anna E. Richardson May 2022

How Flow Regime Affects Predator-Prey Relationships Of Stream Darter And Shiner Species, Anna E. Richardson

Biological Sciences Undergraduate Honors Theses

Analysis of the interactions between abiotic and biotic factors of environments and ecosystems is a highly valued area of research. This study focuses on the interactions between the biotic component of predation and foraging of certain stream fish species and the abiotic component of the flow regime that those species reside in. Gut content analysis followed by statistical calculations in the form of t-tests and chi -quared tests were performed on two fish species who both inhabited a stream with a groundwater flashy flow regime as well as a stream with a runoff flashy flow regime. The research showed that …


Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings May 2022

Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

It is well documented that human activity influences the chemistry of surrounding waters. As such, it is possible that there is a link between land use within a watershed and the chemical composition of the stream. The objectives of this study are to determine if varied land use does affect the concentrations of macronutrients and trace elements present in the streams of Northwest Arkansas, and if so, to determine what extent urban and agricultural development are responsible for these changes. Water samples were collected across 19 streams in the Northwest Arkansas region between January and March of 2022. Water samples …


Analysis Of Edna To Assess Effects Of Water Quality On Freshwater Fungal Diversity In A Virginia Coastal Watershed, Lauren French Apr 2022

Analysis Of Edna To Assess Effects Of Water Quality On Freshwater Fungal Diversity In A Virginia Coastal Watershed, Lauren French

Undergraduate Honors Theses

Freshwater fungi comprise a phylogenetically and functionally diverse group which contributes to wide-ranging ecosystem processes in aquatic systems. Saprotrophic fungi convert detritus into nutrient-rich food sources for fish and invertebrates, whereas pathogenic and parasitic fungi can cause disease and population declines of other aquatic organisms. With their diverse and important roles, changes in freshwater fungal community structure may have far-reaching impacts on ecosystems. To understand how natural and anthropogenic stressors to freshwater systems impact fungal-mediated ecosystem processes, a greater understanding of the taxonomic and functional composition of freshwater fungal communities is needed. We assessed relationships among freshwater habitat types, water …


Lake Huron Shoreline Analysis, Shubham Satish Nandanwar Jan 2022

Lake Huron Shoreline Analysis, Shubham Satish Nandanwar

Theses and Dissertations (Comprehensive)

Lake Huron is a popular tourist destination and is home to several businesses and residents. Since the shoreline is dynamic and is subject to change over the years due to several factors such as a change in water level, soil type, human encroachment, etc., these locations tend to encounter floods due to increased water levels and wind speed. This causes erosion and loss to the properties along the shoreline.

This study is based on two areas of interest named Pinery Provincial Park and Sauble Beach which are located on the shoreline of Lake Huron where Pinery Provincial Park is a …


Changes In Lake Drainage In The Western Canadian Arctic, Dilshan Kariyawasam, Philip Marsh Dr Jan 2022

Changes In Lake Drainage In The Western Canadian Arctic, Dilshan Kariyawasam, Philip Marsh Dr

Theses and Dissertations (Comprehensive)

Nearly half of all Pan-Arctic lakes are situated in the Canadian Arctic, with many of these lakes being of thermokarst origin. Thermokarst lakes are sensitive to changes in the surrounding environment, making them useful indicators to examine the condition of hydrological systems in response to rapid climate warming, a trend which has been well observed in the Canadian Western Arctic. In this study, we use aerial photography to quantify lake area and count changes for lakes in the Inuvik-Tuktoyaktuk region, between 1950 and 2004. A combination of aerial photography and Landsat imagery were used in identifying drained thermokarst lake basins …


Comparing Molecular Methods To Estimate Fish Stomach Contents And Gastric Evacuation Rates: Implications For Measuring The Impacts Of Predation On Central Valley Chinook Salmon, Cory M. Dick Jan 2022

Comparing Molecular Methods To Estimate Fish Stomach Contents And Gastric Evacuation Rates: Implications For Measuring The Impacts Of Predation On Central Valley Chinook Salmon, Cory M. Dick

Cal Poly Humboldt theses and projects

Juvenile Chinook Salmon (Oncorhynchus tshawytscha) migrating through the Sacramento – San Joaquin Delta (the Delta) in central California have higher mortality rates than salmonids migrating through other west coast estuaries. Some hypotheses for high mortality rates include entrainment into water export facilities, physical alterations of the river system, and predation. Of these factors, predation is considered the least understood but may have the largest impact. Predation from large populations of non-native piscivorous fishes in the Delta is believed to effect abundances of Central Valley Chinook salmon, however sufficient data supporting this hypothesis is scarce. In this study, I …


Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee Dec 2021

Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee

Theses and Dissertations

Bioavailable phosphorus loads exported to Lake Michigan from the Milwaukee and Sheboygan River Watersheds appear to have increased in the last 40 years despite meeting total phosphorus (TP) loading goals set by the Great Lakes Water Quality Agreement (GLWQA).Overall, bioavailability of P delivered from the Milwaukee and Sheboygan Rivers was highest during the warmer months, which coincides with the nearshore nuisance algae growth season. However, first order loss rates of SRP calculated during baseflow recession were also greatest during the summer, suggesting that increased river residence time during the summer could reduce export of bioavailable P. Observations of phosphorus partitioning …