Life Sciences Commons^™

Overcoming Barriers To Aquatic Plant Restoration: Addressing Gaps In Species Identification And Planting Techniques In The Intermountain West, Kate A. Sinnott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aquatic ecosystems provide many critical and economically valuable benefits, including drinking water, food, recreational opportunities, and water supply for irrigation and agriculture. However, the health of these systems has been severely impacted by human activities such as pollution, land conversion, and introductions of harmful species. Restoring native aquatic plants can help reverse this damage and reestablish benefits, though it is not a common practice. With an objective to increase capacity for aquatic plant restoration in the Intermountain West, I identified and addressed two major barriers: 1) a lack of confidence in aquatic species identification among wetland professionals, and 2) underdeveloped …

Fishing Out Nutrients: The Spatiotemporal And Ecological Dynamics Of Fishery-Based Nutrient Extraction, Adrián A. González Ortiz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Marine fisheries are one of the most impactful human activities on the planet. Since the 1950s, marine fisheries have removed billions of metric tons of marine biomass leading to substantial declines in many fish populations. Among their impacts, we have begun to investigate the role of fisheries in disrupting marine nutrient cycles. Specifically, removing biomass can change nutrient cycles by reducing the amount of nutrients stored within animal biomass.

No studies have investigated the large-scale geographical and ecological contexts of nutrient removal by fisheries over a large timescale. For my thesis, we compiled data on fishery-targeted organisms' carbon, nitrogen, and …

Dust Deposition Changes Production, Chlorophyll-A And Community Composition In Mountain Lakes, Jiahao Wen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increasing quantities of dust emitted from semi-arid soils, agricultural soils, and urban regions are blown to remote mountain lakes in the American West. Remote mountain lakes lacking local nutrient inputs and presenting simple food webs that are easily affected by climate changes. Dust can carry nutrients (e.g., nitrogen and phosphorus) to mountain lakes and potentially enhance algae growth and change algal communities. However, experimental tests of this hypothesis are lacking. Using in situ experiments, we investigated the effects of dust enrichment on the production, biomass, and primary algal species in three mountain lakes in the American West. We found that …

Nutrient Uptake And Water Quality In Great Salt Lake Wetland Impoundments, Rachel L. Buck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Great Salt Lake (GSL) is the largest inland body of water on the Pacific flyway, a major pathway for migratory birds in the Americas that extends from Alaska to Patagonia. The lake is surrounded by approximately 360,000 acres of wetlands, providing critical food, shelter, cover, nesting areas, and protection to between 4–6 million birds that visit each year. Impounded wetlands were created as part of the GSL ecosystem to support waterfowl habitat. These large, shallow, submergent wetlands are diked to control water levels to sustain aquatic plants which are an important food source. Besides providing critical habitat, these impoundments …

Short- And Long-Term Mechanisms For Increasing Inputs Of Phosphorus In Mountain Waterbodies Of Northeastern Utah, Usa, Jessica Scholz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phosphorus is an essential nutrient that allows life in water to flourish, but changes in phosphorus supplies are not well understood in remote watersheds. In mountain environments, remote watersheds contain critical high-quality water supplies and unique ecosystems, but excess phosphorus can diminish water quality by producing unfavorable aquatic species. Therefore, observed trends of increasing phosphorus concentrations in remote lakes and rivers in the US over the last two decades are a significant concern. Using the Uinta Mountains as a case study, we evaluated three different direct and indirect pathways for phosphorus increases in remote mountain watersheds that may explain observed …

Harmful Algal Blooms: Dominance In Lakes And Risk For Cyanotoxin Exposure In Food Crops, Austin D. Bartos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change and human activities are promoting the dominance of a photosynthetic family of aquatic bacteria, cyanobacteria. Blooms of cyanobacteria are not only a visual nuisance but can produce a variety of cyanotoxins than can harm the liver, skin, and nervous system of animals and humans. We analyzed lakes in the contiguous United States and found that between 2007 and 2012, the number of lakes that produced measurable quantities of cyanotoxins increased from 33% to 45%. Nitrogen and phosphorus pollution were the main drivers of cyanobacteria blooms and toxin production between these years. Many of these lakes and reservoirs are …

Improving Our Ability To Estimate Vital Rates Of Endangered Fishes On The San Juan River Using Novel Applications Of Pit-Tag Technology, J. Benjamin Stout

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimating demographic parameters, such as survival and abundance, with accuracy and precision is vital for detecting trends in populations and assessing the effectiveness of management actions. In most cases, a lack of capture data make estimating parameters very challenging. The use of new technologies to increase the amount of remotely collected data is increasing, but brings new limitations and analytical issues to be resolved. One of those new technologies is the use of a mobile floating PIT-tag antenna to detect PIT-tagged fish. The issue that arises with this technology is determination of the status of detected tags (i.e., live fish …

Improving Aquatic Habitat Representation In Utah Using Large Spatial Scale Environmental Datasets, Gregory C. Goodrum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rivers provide habitat for aquatic species, but widespread human water development degrades aquatic habitat, fragments stream networks, and threatens native fish populations. Habitat suitability models are commonly used to identify current instream habitat conditions, but are often species-specific, data-intensive, and rarely suitable to the large spatial scales required in conservation and water resources management. Thus, there is need to develop and validate habitat suitability models that provide ecologically-meaningful estimations of aquatic habitat, but are simple enough to apply at large geographic areas and flexible to incorporate different species. I tested the accuracy of 15 habitat suitability models estimating Bonneville Cutthroat …

The Abiotic And Biotic Controls Of Arctic Lake Food Webs: A Multifaceted Approach To Quantifying Trophic Structure And Function, Stephen L. Klobucar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Arctic is warming faster than any other region of the globe. To conserve and manage many thousands of lakes across arctic landscapes, scientists need to understand historic and present conditions within these lakes to predict how the lakes, and the organisms that inhabit them, may respond to a changing climate. The goal of my research was to improve our understanding of what physical, chemical, and biological factors contribute to: 1) how lake food webs are assembled; and, 2) how these food webs may change in the future. First, I used long-term observations and lab experiments to determine how fish …

An Evaluation Of Bull Trout Movement Dynamics In The Walla Walla River, Courtney Newlon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bull trout are a fish species listed as threatened under the Endangered Species Act. Historically, they ranged from Northern California at the southernmost extent, into Canada at the northern most extent, and east into Nevada and Montana. Bull trout are highly migratory and require large, unfragmented habitats to persist and are thus highly susceptible to human induced land-use practices. The goal of my thesis was to obtain a better understanding of bull trout movement patterns in the Walla Walla River, Washington using complimentary techniques; Passive Integrated Transponder (PIT) technology and otolith microchemistry. PIT tags can be injected into a fish …

Assessing The Ecological Implications Of The Altered Flow And Sediment Regimes Of The Rio Grande Along The West Texas-Mexico Border, Demitra E. Blythe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large, exotic (those whose headwaters are in distant places) rivers are some of the most unique and diverse ecosystems on earth. Because they often flow through a multitude of biomes and climates, their waters are a vital resource not only for the organisms that inhabit these rivers, but for human societies as well. Thus, large rivers, like the Rio Grande, that flow through arid and agricultural regions are highly regulated and diverted. Regulation and dewatering upset a river’s natural flow regime (e.g., magnitude, duration, timing of large flood events), subsequently impacting the river’s ability to transport its sediment supply, and …

Using Anthropogenic Risks To Inform Salmonid Conservation At The Landscape Scale, Andrew W. Witt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The expansion and industrialization of humanity has caused many unforeseen consequences to the natural world. Due to the importance of freshwater for people, rivers have been particularly altered to meet human needs, often at the expense of the natural world. Supplying water for farms, industries, and cities has reshaped the natural state of rivers by altering river paths, chemistry, and species compositions. These changes have harmed many species that prospered before widespread human alterations, including the native trout and salmon of western North America. As human populations continue to grow, new threats will surface for rivers, and the trout and …

Patterns Of Threatened Vertebrates Based On Trophic Level, Diet, And Biogeography, Shaley A. Valentine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans have indirectly and directly contributed to the extinction of over 500 species within the past 500 years, a rate far higher than we have seen in the past. The high extinction rate and the fact that 18% of vertebrates may become extinct within the next century have pushed Earth into a biodiversity crisis. Understanding what makes species more at risk of extinction is needed to protect Earth’s biodiversity.

Generally, it is expected that predators have greater extinction risk than omnivores and herbivores because predators are larger in body size, depend on other animal species for food, need large home …

Use Of A Net Rate Of Energy Intake Model To Examine Differences In Juvenile Steelhead (Oncorhynchus Mykiss) Densities And The Energetic Implications Of Restoration, C. Eric Wall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bonneville Power Administration (BPA) Fish and Wildlife Program mitigates for impacts of hydroelectric dams on ESA-listed salmon and steelhead populations in the Columbia River Basin (CRB). Considering the sizable investments in mitigation and the diversity of stream habitats within the CRB, there has been a pointed effort to develop and identify meaningful metrics relating to fish populations and trends in their habitat across the CRB. The Integrated Status and Effectiveness Monitoring Program (ISEMP) was developed in 2003 specifically for this purpose, and is tasked with developing and testing strategies for determining the status and trend of salmonid populations and …

Distribution And Drivers Of A Widespread, Invasive Wetland Grass, Phragmites Australis, In Great Salt Lake Wetlands, Arin Lexine Long

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-native invasive plant species can often have negative effects on native ecosystems, such as altered nutrient cycling, decreased habitat for wildlife, and outcompeting native plants. Around the Great Salt Lake (GSL), Utah, the invasive wetland grass Phragmites australis has become abundant in wetlands around the lake. Phragmites is replacing many native wetland plants provide important waterfowl habitat around the GSL. For successful management of Phragmites in GSL wetlands, it is important to know the current distribution of Phragmites, as well as areas that might be vulnerable to future invasion by Phragmites. To do this, we used multispectral aerial …

Trophic Status, Energetic Demands, And Factors Affecting Lahontan Cutthroat Trout Distribution In Pyramid Lake, Nevada, Nicholas A. Heredia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The progression of human development across the landscape has caused declines to both terrestrial and aquatic fauna. Many fishes, specifically native salmonids, have seen reductions in both population size and geographic distribution resulting from reduced habitat, overharvest, and the introduction of non-native predators and competitors. A native North American fish particularly hard hit by these types of actions, Lahontan cutthroat trout, are now limited to less than 10% of their historical habitat, and currently occupy only half of the lakes that they once occupied.

In Pyramid Lake, Nevada, where Lahontan cutthroat trout were once locally extinct, due to overfishing, water …

Morphometric Evaluation Of The Whitefish Complex In Bear Lake, Utah/Idaho, Alan Ward

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitefish populations around the world have long been difficult to categorize taxonomically. The whitefish of Bear Lake, Utah/Idaho are no exception. There are three recognized species of Prosopium that are endemic to the lake. Two of these species, Prosopium spilonotus and Prosopium abyssicota, have previously been indistinguishable outside of spawning times. Previous studies have proposed additional taxa within P. spi/onotus to further complicate the identification among these taxa.

Morphological characteristics were quantified on wild whitefish from Bear Lake, as well as from progeny reared in the laboratory from the wild adult fish. The purported taxa were separated in the field …

Evaluation Of The Effects Of Single Season Wild-Strain Mallard Releases On Local Breeding Population Densities, Charles E. Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1993, to determine if wild-strain mallard releases could be used as a management practice to increase local mallard breeding populations, I released 2,344, 4.5- week-old mallard ducklings (1,200 females and 1,144 males) to wetlands on 12,10.4-km² sites (approximately 200 per site, 100 females, 100 males) in the North Dakota Prairie Pothole Region. I monitored the release sites to determine if any relationship existed between site characteristics and time of release to duckling survival estimates. I conducted breeding pair surveys during 1994 and 1995 on treatment and paired control sites to compare post-release population levels. Lastly, I analyzed return …

Assessment Of Kokanee Salmon, Oncorhynchus Nerka, Genetic Stocks In Flaming Gorge Reservoir, Utah-Wyoming, Michael F. Canning

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I investigated the relative abundance, spatial distributions, return to the creel, and growth rates of two genetic stocks of kokanee salmon, Oncorhynchus nerka, in Flaming Gorge Reservoir, Utah-Wyoming. The two genetic stocks consist of fish from the two major spawning populations of kokanee in the reservoir. One population, Shore Spawners, spawns along the eastern shoreline of the Open Hills area of the reservoir. The other population, Sheep Creek, spawns in Sheep Creek, a tributary located in the Canyon area of the reservoir.

Mitochondrial DNA of kokanee from each population was analyzed to determine haplotype differences between stocks. These haplotype …

Aspects Of The Life History Of Three Catostomids Native To The Upper Colorado River Basin, Charles W. Mcada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The distribution, abundance and life history were studied for three catostomids -- the razorback sucker (Xyrauchen texanus), the flannel-mouth sucker (Catostomus latipinnis), and the bluehead sucker (Catostomus discobolus) -- all native to the upper Colorado River basin. The razorback sucker has declined in abundance due to man's impact upon the system and it has been recommended that this species be listed as ''threatened" on the U. S. Department of the Interior's list of Threatened or Endangered species [Personal corrmunication, G. C. Kobetich, U. S. Fish and Wildlife Service, Las Vegas, Nevada]. During this investigation, …

Ecology Of Spring Fed Salt-Marshes, Eric George Bolen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Any marsh is a distinctive land-form of varied interest. To the agriculturist it is wasteland to be reclaimed; to the naturalist, a habitat of aesthetic value. To the ecologist, however, a marsh represents a complexity of vegetation under the influences of many and often inseparable factors. It becomes a place of challenging study.

Bird Studies Of The Bear River Marshes, Ernest W. Parkinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The establishment of the Bear River Bay Bird Refuge has created for the state of Utah an immense and valuable biological field, a veritable paradise for naturalist and sportsman alike. The naturalist wants a place to study wild life and the sportsman desires game. With the proper control of open seasons on wild fowl the hunting instinct and incentive for the sport should be satisfied for the sportsman. To the naturalist this region will open up bountiful treasures of knowledge that is to be gained only by intense and prolonged scientific study.