Physical Sciences and Mathematics Commons^™

Drought Affects Sex Ratio And Growth Of Painted Turtles In A Long-Term Study In Nebraska, Larkin A. Powell, Ellen P. Dolph, Charrissa R. Neil

School of Natural Resources: Faculty Publications

Climate forecasts suggest the Great Plains of North America have increased risk of droughts during global warming. Environmental factors have potential to influence turtle populations in aquatic habitats through temperature-dependent sex determination and influences on food availability. Long-term studies are critical to evaluate the influence of climatic variation on turtles. We used a 12-year set of mark-recapture data collected from painted turtles (Chrysemys picta, n = 162) in a pond in Keith County, Nebraska during 2005–2016 to assess variation in sex ratio and growth dynamics. Southwest Nebraska experienced two periods of drought during our study (Palmer Hydrologic Drought …

Drought Affects Sex Ratio And Growth Of Painted Turtles In A Long-Term Study In Nebraska, Larkin Powell, Ellen Dolph, Charrissa R. Neil

School of Natural Resources: Faculty Publications

Climate forecasts suggest the Great Plains of North America have increased risk of droughts during global warming. Environmental factors have potential to influence turtle populations in aquatic habitats through temperature-dependent sex determination and influences on food availability. Long-term studies are critical to evaluate the influence of climatic variation on turtles. We used a 12-year set of mark-recapture data collected from painted turtles (Chrysemys picta, n = 162) in a pond in Keith County, Nebraska during 2005–2016 to assess variation in sex ratio and growth dynamics. Southwest Nebraska experienced two periods of drought during our study (Palmer Hydrologic Drought Index [PHDI] …

Climate Change Alters Aging Patterns Of Reservoir Aquatic Habitats, Leandro E. Miranda, Nicky M. Faucheux

United States Geological Survey: Staff Publications

Two slow-moving developments are threatening reservoir aquatic habitats globally: aging and climate change. These events are projected to transform reservoir aquatic habitats in various and often unpredictable ways. Aging affects in-lake habitats directly, whereas climate change affects both in-lake and off-lake conditions. Climate change is expected to accelerate and, in some instances, possibly decelerate aging. Aging can be indexed as functional age, an index that signals the position of a reservoir along its lifespan relying on inlake descriptors of aquatic habitat. Using existing habitat datasets and climate projections, we developed semi-quantitative predictions about the effect of climate change on reservoir …

The Effects Of Hydrologic Heterogeneity On Harmful Algal Blooms In Freshwater Reservoir, Lake Sinclair, Georgia, Margaret Blackledge

Biology Theses

Aquatic habitats are frequently studied after a major water quality problem like the occurrence of an algal bloom. In this study, A proactive rather than a reactive response was considered, where the complexity of conditions conducive to uncontrolled cell growth were studied before a bloom took place by sampling regularly. This study aimed to monitor water quality by monthly sampling of algal communities for approximately one year. As the base of the aquatic food web, algae are a highly diverse group of organisms with varying sensitivity to physical and chemical changes in the environment. Four shallow sites were monitored at …

A Survey Of Hydra Species In Selected South Central Pennsylvania Lakes, Katie Hollen, Kayla Morrill

Summer Scholarship, Creative Arts and Research Projects (SCARP)

Species of the genus Hydra are freshwater invertebrates present in lentic ecosystems around the world. Research on the phylogeny and biogeography of the genus has identified four species groups. However, little work has been done on Hydra ecology during the last forty years, even though the freshwater habitats where they are found are often substantially impacted by human activities. Our project aimed to characterize the distribution of Hydra species in selected lakes in south central Pennsylvania. We sampled six lakes within Lancaster and Dauphin counties. Based on preliminary sampling of a lake on the Elizabethtown campus, we hypothesized that the …

Biolability Of Fresh And Photodegraded Pyrogenic Dissolved Organic Matter From Laboratory-Prepared Chars, K. W. Bostick, A. R. Zimmerman, A. I. Goranov, S. Mitra, P. G. Hatcher, A. S. Wozniak

Chemistry & Biochemistry Faculty Publications

Pyrogenic dissolved organic matter (pyDOM) is known to be an important biogeochemical constituent of aquatic ecosystems and the carbon cycle. While recent studies have examined how pyDOM production, composition, and photolability varies with parent pyrogenic solid material type, we lack an understanding of potential microbial mineralization and transformation of pyDOM in the biogeosphere. Thus, leachates of oak, charred at 400 °C and 650 °C, as well as their photodegraded counterparts were incubated with a soil‐extracted microbial consortium over 96 days. During the incubation, significantly more carbon was biomineralized from the lower versus higher temperature char leachate (45% vs. 37% lost, …

The Effects Of Multiple Stressors On Stream Communities: The Convergence Of Drought, Nutrient Pollution, And Invasive Species, Robert Joseph Fournier Iii

Graduate Theses and Dissertations

Freshwater systems experience multi-faceted degradation from a variety of ecological and environmental stressors. Three common stressors in these systems, drought, nutrient pollution, and invasive species, have wide-ranging effects on stream population- community- and ecosystem dynamics. We have a broad understanding of how each of these stressors works to influence stream systems independently. However, we still know relatively little about if, and how, these stressors might interact when they co-occur. Though drought is a natural part of many stream systems, all three of these stressors can be exacerbated or facilitated by anthropogenic actions. Accordingly, as human population and resource use continue …

A Spatial And Multivariate Approach To Examining Effects Of Urbanization On Nitrogen Sources, Organic Matter Inputs, And Trophic Structure In Streams Of Cobb And Paulding Counties, Georgia., Katharine Horning

Master of Science in Integrative Biology Theses

Urbanization and land use changes have a negative effect on streams often causing numerous physical changes in stream morphology, a change in nutrient concentrations, and altered ecosystems contributing to a loss of habitat, decreased biodiversity, and loss of stability for ecosystem function (Walsh et al., 2005; Meyer et al., 2005; Cardinale and Palmer, 2012). The use of stable isotope analysis for monitoring could be valuable because it accounts for temporal integration from anthropogenic wastewater inputs, characterized by a shift in the abundance of ¹⁵N. This project had three main objectives: (1) to examine how nitrogen and carbon sources are …

Assessment Of Multi-Stressors On Compositional Turnover Of Diatom, Invertebrate And Fish Assemblages Along An Urban Gradient In Pacific Northwest Streams (Usa), Ian Waite, Yangdong Pan, Patrick M. Edwards

Environmental Science and Management Faculty Publications and Presentations

This study is part of the regional stream-quality assessment (RSQA) conducted by the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) project. The purpose of this study is to examine small streams along land-use and stressor gradients at the regional scale and to evaluate the relative importance of instream stressors on diatom, macroinvertebrate, and fish assemblages. In 2015, the RSQA project assessed stream quality in 82 wadeable streams that were selected along an urban land-use gradient in the Pacific Northwest Region (PNW) of the United States. This study evaluates the effects of four major categories of measured instream stressors …

The Limitation Of Spread Of Non-Native Marine Invertebrates From Artificial Structures To Natural Habitats, Whitney Mcclees, Catherine E. De Rivera

ESM Colloquium

Artificial structures created for aquatic anthropogenic activities are often colonized and fouled by many non-native species, few of which have invaded natural areas. Some research has indicated predation is limiting the spread of non-native species, while other research has indicated that it is dispersal-driven. To determine the effects of dispersal limitation and predation on the risk to surrounding habitats of being invaded by non-native species established on marina docks, we used a three-factor design, deploying seven unglazed ceramic panels per each treatment combination of 1) inside versus outside a marina in Yaquina Bay, Oregon; 2) cage keeping out predators >mesh …

Land Use As An Indicator Of Stream Habitat Quality In Salt Creek, Adam Brown

Department of Environmental Studies: Undergraduate Student Theses

This study sought to quantify land use types in Lancaster County and identify which, if any, environmental parameters were significantly influencing fish and invertebrate distribution in the Salt Creek basin. Historical sampling data were obtained from the Nebraska Department of Environmental Quality. Watershed land cover maps were created and the percentages of urban/developed, forested, row crop, and grassland use were calculated. This data was combined with NDEQ water quality parameter, fish, and invertebrate sampling data to conduct nonmetric multidimensional scaling. This analysis did not provide significant conclusions about the driving force of fish and invertebrate distribution in this region because …

The Biological Sediment Tolerance Index: Assessing Fine Sediments Conditions In Oregon Streams Using Macroinvertebrates, Shannon Hubler, David Huff, Patrick M. Edwards, Yangdong Pan

Environmental Science and Management Faculty Publications and Presentations

Fine sediments in excess of natural background conditions are one of most globally common causes of stream degradation, with well documented impacts on aquatic communities. The lack of agreement on methods for monitoring fine sediments makes it difficult to share data, limiting assessments of stream conditions across jurisdictions. We present a model that circumvents these limitations by inferring fine sediments in Oregon streams through sampling of macroinvertebrates. Tolerances to fine sediments (

Aquatic Food Webs And Heavy Metal Contamination In The Upper Blackfoot River, Montana, Jack E. Landers

Graduate Student Theses, Dissertations, & Professional Papers

Acid mine drainage (AMD), characterized by low pH and abundant heavy metals, is a widespread problem affecting water quality and fish habitat in Montana. Montana’s upper Blackfoot River exhibits impaired water quality from historic mining that has significantly degraded aquatic habitat and reduced fish and invertebrate abundance in impacted streams. The goal of this study is to investigate the direct and indirect effects of mine-related heavy metals contamination on aquatic ecosystems by examining changes in aquatic community composition, bioaccumulation, and toxicity risk of heavy metals along a contamination gradient in the upper Blackfoot River. Three primary research questions were addressed …

Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij

Civil and Environmental Engineering Faculty Publications and Presentations

Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of …

Bioenergetics And Habitat Suitability Models For The Chinese Mystery Snail (Bellamya Chinensis), Danielle M. Haak

School of Natural Resources: Dissertations, Theses, and Student Research

Relatively little is known about the invasive Chinese mystery snail (Bellamya chinensis). This research aims to elucidate some of the mystery surrounding this species. First, we place the species in context with other invasive freshwater snails of the USA and Canada, identifying current information gaps, categorizing shared characteristics among families and species, and comparing functional roles and ecological effects of freshwater snails. We conclude that more focus needs to be directed to regulating the aquarium, pet, and food trades if we are serious about preventing future invasions. Next, we develop a bioenergetics model for the species by quantifying …

A Review Of Urban Water Body Challenges And Approaches: (1) Rehabilitation And Remediation, Robert M. Hughes, Susie Dunham, Kathleen G. Maas-Hebner, J. Alan Yeakley, Carl B. Schreck, Michael Harte, Nancy Molina, Clinton C. Shock, Victor W. Kaczynski, Jeff Schaeffer

Environmental Science and Management Faculty Publications and Presentations

We review how urbanization alters aquatic ecosystems, as well as actions that managers can take to remediate urban waters. Urbanization affects streams by fundamentally altering longitudinal and lateral processes that in turn alter hydrology, habitat, and water chemistry; these effects create physical and chemical stressors that in turn affect the biota. Urban streams often suffer from multiple stressor effects that have collectively been termed an “urban stream syndrome,” in which no single factor dominates degraded conditions. Resource managers have multiple ways of combating the urban stream syndrome. These approaches range from whole-watershed protection to reach-scale habitat rehabilitation, but the prescription …

Fluctuations In Chinook Salmon (Oncorhynchus Tshawytscha) Counts At Three Lower Columbia River Spawning Sites, Eric Michael Loomis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Several hypotheses were developed to explore the pronounced increase in Chinook salmon (Oncorhynchus tshawytscha) returning to spawning grounds at the Cowlitz, Kalama, and Lewis Rivers, three tributaries of the lower Columbia River. The study was conducted using data compiled over a ten-year span from 1991-2001. Preliminary indications are that trends in climate are linked to these increases, with the absence of El Niño events and fluctuations in winter precipitation as likely explanations of these phenomena. The unique nature of Chinook life cycles causes them to utilize a variety of habitats that require ideal conditions for maximum survival rates. Correlations between …

Comparison Of Water Quality, Zooplankton Density, And Cover In Razorback Sucker (Xyrauchen Texanus [Abbott]) Spawning Areas Of Lake Mead And Lake Mohave, Michael E. Golden, Paul B. Holden, Southern Nevada Water Authority

Publications (WR)

Las Vegas Bay and Echo Bay in Lake Mead have small, self-sustaining populations of razorback sucker (Xyrauchen texanus [Abbot]). Increased productivity and cover have been hypothesized as reasons for successful recruitment of razorback sucker in Lake Mead. Conversely, reproduction has been documented on Lake Mohave, another lower Colorado River reservoir, but no recruitment has been observed. In 2000, BIO-WEST, Inc. was contracted by the Southern Nevada Water Authority to design and implement a study to examine nutrient levels, zooplankton density, and cover in areas with and without razorback sucker recruitment success. We sampled Echo Bay, Las Vegas Bay, and …

A Comparison Of Advanced Time Series Models For Environmental Dependent Stock Recruitment Of The Western Rock Lobster, Saarah A. Farag

Theses: Doctorates and Masters

Time series models have been applied in many areas including economics, stuck recruitment and the environment. Most environmental time series involve highly correlated dependent variables, which makes it difficult to apply conventional regression analysis, Traditionally, regression analysis has been applied to the environmental dependent stock and recruitment relationships for crustacean species in Western Australian fisheries. Alternative models, such as transfer function models and state space models have the potential to provide unproved forecasts for these types of data sets. This dissertation will explore the application of regression models, transfer function models, and state space models to modelling the puerulus stage …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume Ii Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume I Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Time To Metamorphosis As A Function Of Larval Size In A Population Of Ambystoma Tigrinum Salamanders Consisting Of Cannibal And Typical Morph Phenotypes, Michael J. Lannoo, Michael P. Sweet, Nancy M. Ladehoff, Edmund S. Fangman, William B. Collins

Journal of the Iowa Academy of Science: JIAS

Salamander larvae of the species Ambystoma tigrinum are dimorphic in northwestern Iowa. In addition to common typical morphs, there exist rare, specialized cannibal morphs, which are induced environmentally by crowding. Cannibal morph phenotypes are characterized morphologically by their large size, proportionately large heads and hypertrophied vomerine teeth, and behaviorally by facultative cannibalism. During metamorphosis amphibians are particularly sensitive to predation. To help understand why cannibal morphs are uncommon, we have raised cannibal and typical morphs in isolation and under crowded conditions to compare the timing and duration of metamorphosis between these morphs. Results show that larger larvae, most of which …

Temporal And Spatial Variation In Pelagic Fish Abundance In Lake Mead Determined From Echograms, Gene R. Wilde, Larry J. Paulson

Publications (WR)

Echograms have been used extensively to locate and estimate the relative abundance of marine fish stocks (Cushing 1973). In freshwater, echograms have been used to describe vertical (Netsch et al. 1971; Eggers 1978; O'Brien et al. 1984; Matthews et al. 1985), spatial (O'Brien et al. 1984; Wanjala et al. 1986) and temporal (Baker and Paulson 1983) patterns in fish abundance. Although most uses of echograms have been qualitative, Mullan and Applegate (1969) and Matthews et al. (1985) obtained relative estimates of fish abundance by counting targets (fish) on echograms. However, neither Mullan and Applegate (1969) nor Matthews et al. (1985) …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines.

Because …

Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel

Publications (WR)

Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and fiannehnouth sucker), the final preferendum is a less precise indicator of probable distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a …

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

Publications (WR)

Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures.

Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …

The Role Of Nannoplankton In The Phytoplankton Dynamics Of Four Colorado River Reservoirs (Lakes Powell, Mead, Mohave, And Havasu), Jeffrey John Janik

Publications (WR)

Phytoplankton species composition and community size structure were studied in four warm-monomictic Colorado River reservoirs; lakes Powell, Mead, Mohave, and Havasu from March 1981 to February 1982. Sampling was done at approximately monthly intervals from several stations in each reservoir. The Utermohl technique was used to enumerate phytoplankton. The phytoplankton assemblage was divided into the following six size classes using microscopic techniques; netplankton (>64 um), and nannoplankton (>5, 5-11, 12-21, 22-44, and 45-64 um).

Total phytoplankton biomass and community size structure were different among these four reservoirs with considerable spatial and temporal variation present. Average reservoir-wide areal weighted …

Development, Verification And Use Of Methods To Model Chemical And Thermal Processes For Lakes Mead And Powell, John Eric Edinger, Edward M. Buchak, Joseph S. Norton, Bureau Of Reclamation

Publications (WR)

Analysis and development of carbonate-bicarbonate chemical subroutine.

Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki

Publications (WR)

The ¹⁴C light and dark bottle technique for measurement of primary production was utilized as a means of assessing the amount of inorganic carbon being converted Into organic form by the photosynthesis of phytoplankton populations In the Boulder Basin of Lake Mead.

Spatial and time series changes of productivity levels observed at eight sampling locations within Boulder Basin Indicate that the Influence of treated municipal arts' industrial effluent flowing into Les Vegas Bay is contributing high levels of available nutrients at Las Vegas Wash Inlet to cause productivity to approximate those levels associated with polluted waters.

Productivity levels at …

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation

Publications (WR)

Progressive increases in concentration of dissolved solids in the Colorado River water from Lake Powell to Imperial Dam seem to alter plankton dynamics and biological productivity of the river. Also, changes in biological productivity and micronutrients concentrations occur within the same reservoir. Development of a digital simulation model to predict micronutrients concentrations and biological productivity is necessary for diagnosing changes in plankton population and effluent-carrying capacity of the system.

The objectives of the study are: (1) to determine trace metal balance at different locations in Lake Mead, (2) to measure biological productivity and conduct plankton population counts at each sampling …