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Full-Text Articles in Life Sciences

Anthropogenic Litter In Illinois Streams: Monitoring, Distribution, And Relationship To Biological Indicators Of Stream Health, Lauren Wisbrock Jan 2021

Anthropogenic Litter In Illinois Streams: Monitoring, Distribution, And Relationship To Biological Indicators Of Stream Health, Lauren Wisbrock

Master's Theses

Anthropogenic litter (i.e., trash; AL) is increasing in aquatic ecosystems worldwide. AL shows a patchy, uneven distribution in lotic ecosystems due to heterogeneity in its sources, how it moves, and mechanisms of retention. In addition, the diversity of material types, size, and mobility makes developing techniques to measure AL assemblage in rivers a challenge. In rivers, watershed land-use and riparian features likely impact AL abundance and composition, but this impact is not fully understood. Measuring AL can be time consuming and labor intensive, so rapid assessments are needed for ecosystem managers to quantify the level of AL impairment in a …


The Effect Of Plastic On Leaf Litter Breakdown In Urban Streams, Lisa Haneul Kim Jan 2020

The Effect Of Plastic On Leaf Litter Breakdown In Urban Streams, Lisa Haneul Kim

Master's Theses

The plastic component of anthropogenic litter (AL) is an emerging ecological concern and has been a focus of research, as it is long-lived, mobile, interacts with physical and chemical components of aquatic ecosystems, and breaks down into smaller pieces (i.e., microplastic, <5mm particles). Rivers are considered a major source of plastic to oceans, but little is known about plastic's abundance, distribution, and effects on ecological processes in urban streams. Previous studies report plastic is abundant in freshwater systems, especially in naturally occurring debris dam structures and overhanging vegetation which accumulate high quantities of AL, especially plastic items (i.e. bags, wrappers, packaging material), along with leaf litter and other coarse particulate organic matter. in temperate, forested streams, leaf litter is a critical food source and plays an essential role in the stream food web. the rate at which leaves break down is affected by many variables such as hydrology, water chemistry, and macroinvertebrate and microbial communities. We predicted that plastic accumulation along with leaf litter can slow leaf breakdown by reducing diversity and abundance of microbial decomposers, as well as macroinvertebrate consumers. We measured leaf breakdown, and characterized macroinvertebrate and microbial (i.e., bacterial, fungal, algal) communities in 3 litter bag treatments: leaves alone, plastic alone, and leaves mixed with plastic. Although plastic did not reduce leaf breakdown rates or have a significant effect on macroinvertebrate consumer communities, it showed distinct microbial communities compared to leaf substrates. Results will provide a new understanding of how plastic and microbial communities interact, and set the framework for future studies to look at microbial succession and macroinvertebrate diversity on other synthetic substrates in freshwater systems.


Microplastic In Aquatic Food Webs: Museum Specimens And Ingestion Experiments Reveal Controls On Microplastic Ingestion By Freshwater Fish, Loren Hou Jan 2019

Microplastic In Aquatic Food Webs: Museum Specimens And Ingestion Experiments Reveal Controls On Microplastic Ingestion By Freshwater Fish, Loren Hou

Master's Theses

Plastic is pervasive in modern economies and ecosystems. Early research suggests freshwater fish commonly ingest microplastic (particles < 5 mm), which may influence fish digestive tissues, but no studies have examined historical patterns in microplastic consumption or rates of microplastic retention in fish. We measured microplastic in digestive tissue of specimens collected and preserved over the last century (Field Museum, Chicago). We selected Micropterus salmoides (largemouth bass), Notropis stramineus (sand shiner), Ictalurus punctatus (channel catfish), and Neogobius melanostomus (round goby) because each was well represented in the museum collection, with specimens from urban rivers. Specimens from 1900-2018 showed increases in microplastic concentration from the 1950's to present. in a second project, we collected round gobies from Lake Michigan in Chicago to conduct feeding experiments to measure microplastic ingestion and retention rates. the majority of microplastic was excreted within 72 hours of ingestion. Results will aid in understanding ecological interactions of microplastic and freshwater fish, informing further work on the movement of microplastic in aquatic food webs.


Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack Jan 2018

Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack

Master's Theses

Chironomidae (Diptera) surface-floating pupal exuviae were collected monthly during the ice-free season in 2010-2011 from six lakes in the North Temperate Lakes Long-Term Ecological Research site in northern Wisconsin. The goal of this study was to determine whether chironomid community structure reflected differences in lake morphometry (i.e., depth, area, shoreline development, etc.), water chemistry, and/or landscape position (i.e., elevation). Forty-six genera were identified from four subfamilies: Chironominae (57%), Orthocladiinae (28%), Tanypodinae (11%), and Diamesinae (4%). Tanytarsus, Ablabesmyia, and Psectrocladius were found in all six study lakes; whereas certain genera, such as Omisus, Protanypus, and Epoicocladius were each observed in only …


Population Genetics And Distribution Of The Oriental Weatherfish, Misgurnus Anguillicaudatus, In Chicago Area Waterways, John Belcik Jan 2017

Population Genetics And Distribution Of The Oriental Weatherfish, Misgurnus Anguillicaudatus, In Chicago Area Waterways, John Belcik

Master's Theses

Oriental Weatherfish (Misgurnus anguillicaudatus), native to Southeast Asia, are freshwater fish belonging to the family Cobitidae (loaches). They are benthic fish with the ability to breathe atmospheric air, and exhibit an unusual behavior of swimming vertically in the water column in response to changes in barometric pressure. Oriental Weatherfish appear to be successful invaders to North American waterways. Within the last century they have been sighted in freshwater systems throughout the United States, yet the distribution and source of this invasion are largely unknown. This study investigates the distribution patterns, surveying methods, and population genetics of the Oriental Weatherfish within …


Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker Jan 2016

Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker

Master's Theses

With current declines of vertebrate taxa meeting or exceeding those of historic mass extinction events, there is a growing need to investigate the main drivers of declines. Amphibians are perhaps at greatest risk of global climate change and land-use changes than most other vertebrate classes and also have significant roles in ecosystem processes – combined, this creates a cause for concern. I designed a study that would investigate the effects of current and predicted climate change and land-use changes on amphibians using species distribution models and a field study to identify the potential consequences of amphibian species declines by investigating …


Early Round Goby (Neogobius Melanostomus) Invasion Into Lake Michigan Tributaries And Competitive Interactions With Two Native Benthic Fishes., Margaret Ann Malone Jan 2016

Early Round Goby (Neogobius Melanostomus) Invasion Into Lake Michigan Tributaries And Competitive Interactions With Two Native Benthic Fishes., Margaret Ann Malone

Master's Theses

The round goby is a prolific invasive species and is currently spreading into Great Lake tributary streams. There is a high potential for negative impacts on native benthic fishes in these stream habitats and the aim of this study is to assess the impacts of the round goby on two native darter species in particular (johnny darter and blackside darter). I review the history of round goby invasion in the Great Lakes and summarize hypotheses of the invasive characters of the round goby. Using game theory, I provide a G-function approach to understanding the outcomes of the round goby invasion …


Aquatic Insect Community Structure And Secondary Production In Southcentral Alaska Streams With Contrasting Thermal And Hydrologic Regimes, Samantha D. Hertel Jan 2016

Aquatic Insect Community Structure And Secondary Production In Southcentral Alaska Streams With Contrasting Thermal And Hydrologic Regimes, Samantha D. Hertel

Master's Theses

Streams along the Copper River Delta, southcentral Alaska, exhibit contrasting thermal and hydrologic variability associated with being primarily groundwater-fed (GWF) or surface water-fed (SWF). Groundwater-fed streams are predictable both thermally and hydrologically year round, whereas SWF streams are unpredictable and exhibit more variable thermal and hydrologic regimes. These differences may strongly influence aquatic insect community structure and secondary production. Four streams, two GWF and two SWF, were sampled twice monthly from late April 2013 through August 2013 and once seasonally in fall (September) and early winter (November). Aquatic insect community structure differed markedly in both hydrologic types. Taxa richness was …


The River Continuum Redux: Aquatic Insect Diets Reveal The Importance Of Autochthonous Resources In The Salmon River, Idaho, Kathryn Vallis Jan 2011

The River Continuum Redux: Aquatic Insect Diets Reveal The Importance Of Autochthonous Resources In The Salmon River, Idaho, Kathryn Vallis

Master's Theses

Along a river network, changes in the physical characteristics of a stream - changes articulated by the River Continuum Concept (RCC) - have been predicted to influence stream food webs, particularly the resources supporting aquatic macroinvertebrates. Although diets of macroinvertebrates can track resource availability along the longitudinal gradient of streams, insect diets were not assessed in the original RCC study; rather, insects were grouped into functional feeding groups (FFGs). In addition, global climate change is increasing the frequency and spatial extent of wildfire and beetle outbreaks throughout the western United States and could affect riparian vegetation and the amount of …


Community Structure And Secondary Production Of Aquatic Macroinvertebrates In Coastal Wetland Ponds Of The West Copper River Delta, Alaska, Following Tectonic Uplift, Ryan Glen Van Duzor Jan 2011

Community Structure And Secondary Production Of Aquatic Macroinvertebrates In Coastal Wetland Ponds Of The West Copper River Delta, Alaska, Following Tectonic Uplift, Ryan Glen Van Duzor

Master's Theses

The Great Alaska Earthquake of 1964 (magnitude 9.2) greatly altered the coastal landscape in southcentral Alaska and had particularly dramatic effects on the Copper River Delta (CRD), an ecologically and economically important area within the Chugach National Forest. The earthquake caused tectonic uplift (up to 3.5m) of the CRD coastal tidal marsh and transformed it into a perched freshwater marsh. Copper River Delta ponds, which are crucial habitat to a myriad of migrating songbirds, shorebirds, and waterfowl, are of particular interest to wildlife managers in the CRD and along the Pacific coasts of North, Central and South America. This study …


Fish Assemblage Structure In Natural, Channelized, And Restored Sections Of Nippersink Creek, Mchenry County, Illinois, Sarah Ann Zack Jan 2010

Fish Assemblage Structure In Natural, Channelized, And Restored Sections Of Nippersink Creek, Mchenry County, Illinois, Sarah Ann Zack

Master's Theses

Degradation of aquatic habitats and loss of biodiversity are growing concerns of natural resource managers and the general public. Channelization, the common historical practice of straightening streams and rivers for agricultural interests, has had profound detrimental effects on the biodiversity of lotic fish assemblages. Nippersink Creek, McHenry County, IL is a twenty-three mile stream that flows through an area valued for its fish, wildlife, and invertebrate biodiversity. Although a portion of the stream was channelized in the 1950's, restoration efforts by the McHenry County Conservation District have recently restored historical meanders. Nevertheless, efforts to restore streams and rivers to their …


The Effects Of Crayfish Grazing On Benthic Algal Community Dynamics In Southwestern Lake Michigan, Kristi A. Zenchak Jan 1993

The Effects Of Crayfish Grazing On Benthic Algal Community Dynamics In Southwestern Lake Michigan, Kristi A. Zenchak

Master's Theses

No abstract provided.