Digital Commons Network^™

Quantifying The Relative Importance Of Boat Wakes In Fetch-Limited Environments, Abigail Maria Carswell

Electronic Theses and Dissertations

Wind waves and wave-generated currents are known to contribute to shoreline change, but there is increasing evidence that vessel-generated waves (i.e., boat wakes) may be responsible for erosion of shorelines in fetch-limited environments. Depending on vessel type and speed of operation, boat wakes have also been shown to be capable of resuspending sediment, degrading habitat, and water quality, and causing damage to shoreline infrastructure. The number of cottages and recreational boats on inland lakes has been steadily increasing in recent decades in Ontario, Canada, which has resulted in a growing perception that boat wakes are detrimental to the environment, infrastructure, …

Boat Wake Attenuation Through Artificial Vegetation - A Case Study From Peche Island, Jamie Kathryn Lilly

Electronic Theses and Dissertations

The use of nature-based solutions and engineering ideas has sparked interest in the value of vegetated shorelines for protecting against erosion. However, there is a lack of field data, and more research is needed to understand how effective vegetation is in reducing the impact of wind waves and boat wakes. The difference in period between wind waves and boat wakes suggests that they may be attenuated differently, requiring further study to determine the optimal management design. The purpose of this study is to quantify the ability of artificial vegetation to attenuate boat wakes and calculate the drag coefficient for model …

Quantifying Survival And Behaviour Of Hatchery-Reared Juvenile Bloater Stocked Across Bathymetric Depths In Lake Ontario, Lydia L. Paulic

Electronic Theses and Dissertations

Over 20 million native and non-native fishes are stocked into the Great Lakes annually as part of restoration initiatives and to support commercial and recreational fisheries. Bloater (Coregonus hoyi), a deep-water planktivore that was extirpated from Lake Ontario in the 1980s, has been consistently stocked in the lake since 2012 by Canadian and American natural resource agencies with the goal of producing a self-sustaining population. Previous research has highlighted challenges with stocking such as poor survival, attributed to high predation, potential maladaptive behaviour and barotrauma resulting from introducing a hatchery-reared species into a foreign environment. To address these survival challenges, …

Influence Of Landscape And Nutrients On Stable Isotope Dynamics And Food Webs In A River Prior To Re-Establishing Fish Migration, Selina Al-Nazzal

Electronic Theses and Dissertations

Great Lakes tributaries are undergoing major ecosystem restoration through dam removal aimed at improving habitat connectivity. Re-establishing connectivity can have consequences for both desirable and undesirable species, especially in watersheds that risk the invasion of non-native species. To predict and evaluate the effects of reconnecting native fish habitats, I used stable isotopes of carbon (δ13C), nitrogen (δ15N), and sulphur (δ34S), spatial stream network (SSN) models and trophic niche measurements to examine the influence of land cover and nutrient concentration on the trophic ecology and distribution of stable isotopes of biofilm, macroinvertebrates, and fishes in the Boardman/Ottaway River (BOR), a tributary …

Root System Response Of Soybean To Microplastics Of Varying Types And Concentrations, Deqa Farow

Electronic Theses and Dissertations

Biosolid fertilizer use causes the input of microplastics into the rhizosphere where they may interfere with root interactions with the soil and microbial community and thereby hinder plant acquisition of nutrients and water. However, it is unclear what microplastic concentration or types affect plant root system and when these impacts manifest. Using the rhizobox method, soybeans were grown in soil was dosed with microplastic mimics (PET sheets and PP beads at 2,000 and 15,000 particles / kg dry soil) and biosolids. A time-series analysis was conducted on plant root traits using non-destructive imaging with an Epson 12000xl scanner of the …

The Effects Of Biosolid Microplastics On The Microbial Community And Root Functioning In The Rhizosphere Of Soybean Crops In Agricultural Soil, Rebecca Chloe Lebel

Electronic Theses and Dissertations

Biosolids are semi-solid by-products from wastewater treatment plants where contaminants such as microplastics can accumulate, and transfer into the root zone causing ecotoxic effects to the rhizosphere microbial community. Furthermore, microplastics can alter soil properties which have a strong control on the size and diversity of the rhizosphere microbial community and its ability to consume root-borne carbon compounds. Using the MicroRESP system the respiration of the rhizosphere microbial community of soybeans subjected to microplastic biosolid mimics of two types (PET sheets and PPT beads) and two concentrations (2,000 vs 15,000 particles/kg dry soil) was quantified. Baseline respiration rates from extracted …

The Influence Of Spatiotemporal Variation In Food Web Models, Cecilia E. Heuvel

Electronic Theses and Dissertations

Aquatic ecosystems are constantly adapting to fluxes in season, temperature, nutrient cycling, and prey availability. Consequently, aquatic food webs are dynamic, and relationships between species are perpetually changing as organisms and primary producer communities adapt to current environmental conditions both in time and space. Despite this knowledge however, many food web studies continue to use temporally static and spatially homogenous representations of food webs. This thesis proposes that a detailed investigation of temporal and spatial trends in a large lake ecosystem can improve our understanding of the mechanisms and drivers of spatial and temporal variation in food web structure and …

Using Harmonization To Examine Freshwater Mussel Species At Risk: A Sydenham River Watershed Case Study, Julia Ann Willsie

Electronic Theses and Dissertations

There are over 300 species of freshwater mussels (Family: Unionidae) across North America with many populations at risk or in decline. Mussels provide essential ecosystem services, yet they remain largely underexplored in terms of distribution, population sizes, life history traits, and co-existence with hosts, making species conservation efforts a challenge. To advance the conservation of freshwater mussel species at risk of extinction (SAR), this thesis aims to extend understanding of freshwater mussel SAR distributions in a biodiverse but vulnerable watershed in the Laurentian Great Lakes basin. This thesis asks: How can freshwater mussel SAR distribution data be leveraged through existing …

Influence Of Lake Volume On Trophic Position, Carbon Use, And Resource Partitioning In Fish Across A Narrow Range Of Ecosystem Size, Alyssa Andersen

Electronic Theses and Dissertations

Lake size is an important factor governing seasonal variation in limnological phenomena, origin of nutrient sources, species interactions, cross-habitat linkages, and trophic pathways, all having complex influences on food web structure and function. Lake size effects are most clearly demonstrated across very wide gradients in surface area or volume. This approach incorporates several complicating and collinear elements such as changing fish assemblages and species richness, and therefore, incorporates additional but unaccounted shifts in food web structure and function. A comparison across a finer lake size gradient where fish assemblages and species richness change little or not at all is needed …

The Characterization Of Riparian Vegetation In Agriculture Drains Impacted By Phragmites Australis And Drain Management: A Southwestern Ontario, Canada Case Study, Ryan Mackenzie Graham

Electronic Theses and Dissertations

Agricultural drainage systems are important components of regional ecosystems and play key roles in ecosystem functioning. Biodiversity is a service provided by drains which is not fully understood in agriculturally dominated areas and is disrupted consistently by drain management, specifically in drains invaded by Phragmites australis. The objective of this thesis was to characterize the contribution of regional vegetational biodiversity provided by drainage systems, across sites representing a gradient of management frequencies. Drains were separated into management categories: Low (managed +5 years ago), Medium (managed every 3-5 years), or High (managed yearly). Plant abundance was measured and biodiversity indices (Species …

Macroinvertebrate And Bacteria Community Responses To Tributary Inputs At Coastal Wetlands Of The Detroit River, Ontario, Canada, Jessica Robson

Electronic Theses and Dissertations

The Detroit River is a Great Lakes Area of Concern with five monitored wetlands in the Canadian jurisdiction. Habitat assessments have indicated possible stress at wetlands receiving inflow from Turkey Creek and River Canard tributaries. These assessments are made within the tributaries. Yet, macrophyte beds extend into the river upstream and downstream and are important biodiversity habitats. This thesis examines benthic macroinvertebrate and sediment bacteria community compositions for differences with respect to tributaries by two means. First, we examine inter-wetland differences for resemblance to water quality. We had found by NMDS and PERMANOVA that neither taxonomic group resembled water quality …

Dynamic Distributed Energy Resources For Expansion Of Ontario’S Greenhouse Sector, Lysandra Naom

Electronic Theses and Dissertations

The vegetable greenhouse sector is rapidly growing and adopting technology advances like supplemental lighting. Supplemental lighting has a dynamic impact on the demand and consumption of a greenhouse’s electricity load. There is uncertainty on the rate of adaptation of technologies and the impact this could have on the power consumption of the sector. Without electricity availability, the sectors innovation and expansion can come to a halt. This research focused on investigating greenhouse electrical load models and lighting trends to forecast demand on electricity grids and discover potential for Distributed Energy Resource (DER) applications.

This thesis presents a series of studies …

Cytotoxicity And Reproductive Impairment In Rainbow Trout Cell Lines Exposed To Microcystis Aeruginosa Extracellular Metabolites, Keira Harshaw

Electronic Theses and Dissertations

Current trends in cyanobacterial harmful algal blooms (cHABs) demonstrate increasing risks to human health and the health of aquatic ecosystems around the globe. Expansion of algal blooms, both geographically and temporally, serve to place increasing numbers of freshwater species, including fish, in peril. Microcystis aeruginosa, one of the most common species of bloom-causing cyanobacteria, is capable of producing a vast diversity of biologically active compounds, however Microcystis studies are often dominated by microcystins. How non-microcystin metabolites contribute to Microcystis toxicity, particularly in freshwater fish, has been the subject of a limited, but growing, body of research. To contribute to …

The Characterization Of Riparian Vegetation In Agriculture Drains Impacted By Phragmites Australis And Drain Management: A Southwestern Ontario, Canada Case Study, Ryan Mackenzie Graham

Electronic Theses and Dissertations

Agricultural drainage systems are important components of regional ecosystems and play key roles in ecosystem functioning. Biodiversity is a service provided by drains which is not fully understood in agriculturally dominated areas and is disrupted consistently by drain management, specifically in drains invaded by Phragmites australis. The objective of this thesis was to characterize the contribution of regional vegetational biodiversity provided by drainage systems, across sites representing a gradient of management frequencies. Drains were separated into management categories: Low (managed +5 years ago), Medium (managed every 3-5 years), or High (managed yearly). Plant abundance was measured and biodiversity indices …

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, …

Sediment Microbial Community Diversity And Function In Response To Legacy And Prevailing Pollutants In Southern Ontario Watersheds, Nicolas Falk

Electronic Theses and Dissertations

Managing and mitigating point and non-point contamination to freshwater resources depends on reliable and sensitive monitoring of ecosystem health. Microorganisms in surface waters and sediments respond rapidly to anthropogenic disturbances, making them valuable bioindicators of human-induced landscape change. However, there lacks a baseline understanding of microbial community composition and function in industrially and agriculturally impacted regions of the Great Lakes. Without a reference state of microbial diversity and activity, future investigations seeking to integrate microorganisms into ecosystem assessments will lack context. Using genomic tools and measurements of chemical and nutrient contaminants, this thesis provides case studies of microbial community responses …

Consequences Of Environmental Manipulation On Behavioural And Neuromorphological Plasticity As It Relates To The Reintroduction Of Atlantic Salmon (Salmo Salar) To Lake Ontario, Ali I. Mokdad

Electronic Theses and Dissertations

The reintroduction of imperilled species has become an important tool in conservation biology and relies on the captive-rearing of remaining individuals, or a subset thereof, as a lifeline to prevent extinction. The success of reintroduction efforts has generally been low, mainly due to poor post-release performance of captive-reared animals. Captive-breeding programs tend to produce behaviourally and neurologically compromised animals that deviate from wild phenotypes and are less fit in natural settings. While genetic adaptation can account for some of the behavioural deficiencies expressed by captive-reared animals, phenotypic plasticity has been shown to play a large role. Phenotypic plasticity is generally …

Characterizing Carbon In Agricultural Landscapes, Lauren Ann Weller

Electronic Theses and Dissertations

Soil organic matter (SOM) is an important pillar of soil fertility and ecosystem health. However, uncertainty exists both in the evaluation of agricultural conservation measures for specific local contexts and the sensitivity of the analytical tools used. Therefore, the objective of this thesis was to characterize organic matter from agricultural soils, focusing specifically on addressing field- and analytically based uncertainties associated with the ultraviolet-Visible (UV-Vis) and fluorescence spectroscopy of water-extractable organic matter (WEOM), and using the clay-dominated soils of Essex County as a case study. Here I explored optical spectroscopy properties across a gradient of agricultural practices and restoration to …

Patterns And Behaviours Of Barrier Breaching In Lacustrine Environments: A Case Study From The Point Pelee Foreland, Jenny Gharib

Electronic Theses and Dissertations

The Great Lakes are non-tidal, but experience significant water level fluctuations at hourly, seasonal, and decadal scales. In response to elevated water levels, barrier beach-ridges, including those located on the eastern shore of the Point Pelee foreland, experience accelerated erosion, overwash, and breaching leading to the removal or burial of vegetation, and damage to infrastructure and vulnerable habitat. Historical aerial imagery between 1931–2022 and annual average lake levels between 1920–2022 were examined to characterize barrier retreat and breach initiation, expansion, and closure. The timing and rate of transgression and progradation, overwash, and breaching are dependent on decadal-scale variations in water …

Detection Of Endangered Fish In Dianchi Lake, Kunming, China, Using Edna And Traditional Fishing, Kai Zhang

Electronic Theses and Dissertations

Dianchi Lake, Yunnan, China is a eutrophic plateau lake. Many native fish species in the lake are currently endangered or extinct due to a variety of stressors. Community surveys are important for ecological management and protection, though efforts are hampered by low abundance of some species. The goal of this thesis was to understand the community structure and distribution of fish in Dianchi Lake and to detect Sinocyclocheilus grahami, a critically endangered species endemic to the lake, using both traditional netting methods and environmental DNA. Using traditional netting and trapping, I found that the fish community of …

Mosquito Species Distribution Models: Limitations And Best Practices, Justin Barker

Electronic Theses and Dissertations

Understanding species distribution is fundamental to ecology and biogeography, with important implications for species management. This is especially true for species of public health concern—such as mosquitoes—which can impart both economic and health impacts. Species distribution models (SDMs) are powerful tools to accomplish this goal. However, obtaining reliable conclusions, those which are accurate and applicable for policy development, from SDMs is not straightforward owing to the many required considerations such as objective with respect to limitations of the available data. The goal of this thesis was to determine recommended methods to address known and unknown mosquito SDM limitations. First, I …

Understanding Freshwater Ecosystems And Human Health Implications In Recreational Water Through Microbial Characterization, Source Tracking, And Sediment-Microbe Dynamics, Danielle Gleason

Electronic Theses and Dissertations

Contamination of natural aquatic ecosystems is a serious global concern as populations increase and the environment is impacted by climate change. Nonpoint source (NPS) contamination of allochthonous materials, such as sediments, nutrients, and microorganisms, is commonly introduced to a body of water through runoff and wash-off which cumulates over a large area, and is subsequently transported to surface waters (e.g., rivers, streams, lakes) and shorelines. The principal form of microbial contamination of water resources is often from fecal pollution derived from humans, domesticated animals, or wildlife, and contains a variety of human pathogens. There are also numerous factors (with limited …

The Development And Application Of Targeted Edna Metabarcoding For Monitoring Freshwater And Marine Ais, Yueyang Wu

Electronic Theses and Dissertations

Species invasions are of critical concern due to their significant impacts on ecosystems and social economies, of which aquatic invasive species (AIS) often pose significant challenges in their control and management, notably because of difficulties in early detection. Environmental DNA (eDNA) provides a promising tool in advancing the detection of newly introduced aquatic organisms because of its high sensitivity and ease of use compared to traditional capture-based methods. Although eDNA-based methods are increasingly used worldwide, especially in aquatic ecosystems, most studies focus on a limited number of target species despite a pressing need for broad taxonomic monitoring for conservation and …

Population Genetic Analyses Of Arctic Char (Salvelinus Alpinus) Life History Types In Nettilling Lake & Amadjuak River Ecosystem: A Test Of Reproductive Isolation, Chen Liu

Electronic Theses and Dissertations

A great number of studies have identified strong genetic differences between sympatric anadromous and resident populations of Salmonidae. However, Arctic char (Salvelinus alpinus) migratory phenotypes in the Nettilling Lake and Amadjuak River ecosystem in Nunavut, Canada have not been genetically characterized, and it remains unclear if distinct genotypes and phenotypes associated with migratory life history differences are maintained through reproductive isolation, and they have been assumed to be sympatric populations, or co-occurring populations. Co-occurring Arctic char (n=225) were sampled from eleven sites along the Amadjuak River in 2014 and 2015. Twelve microsatellite loci were used to quantify genetic variation among …

Assessing The Adaptive Capacity Of An Arctic Seabird To Increasing Frequency In Predation Risk From Polar Bears Using Behavioural And Physiological Metrics, Erica Anne Geldart

Electronic Theses and Dissertations

Predator-prey dynamics in the Arctic are being altered with changing sea-ice phenology. The increasing frequency of predation on colonial nesting seabird eggs by a rare predator - the polar bear (Ursus maritimus), is a consequence of bears shifting to terrestrial food resources through a shortened seal-hunting season. I study a colony of nesting common eiders (Somateria mollissima) on Mitivik (East Bay) Island, Nunavut, Canada, that is exposed to established nest predators such as arctic fox (Vulpes lagopus), but has recently experienced an increase in polar bear nest predation due to the bears’ lost on-ice hunting opportunities. Given eiders’ limited eco-evolutionary …

Multifaceted Environmental Enrichment In Industrial Fish Hatcheries: The Influence Of Enriched Rearing On The In-Situ Behaviour And Post-Stocking Success Of Juvenile Atlantic Salmon (Salmo Salar), Justine Elizabeth Mcandrews

Electronic Theses and Dissertations

Hatchery fish reared and stocked to sustain or restore wild populations often perform poorly in novel environments compared to their wild counterparts. To combat maladaptive hatchery-acquired traits environmental enrichment is an emerging tool used to provide ‘life skills training’ to hatchery fish prior to release. Through the application of simple yet multifaceted enrichment protocols in an industrial fish hatchery, this thesis aimed to demonstrate how enrichment could be applied to improve the ecological viability of stocked fish. At a provincially-run fish hatchery, a subgroup of juvenile Atlantic salmon (Salmo salar) were subject to 10 weeks of environmental enrichment …

Physiological State Determinants Of Maternal Cortisol Signaling And Its Impact On Offspring Quality And Fitness, Sydney Currier

Electronic Theses and Dissertations

Assessing the intergenerational effects of maternal stress is important for predicting how offspring will respond to changing environments. The overall aim of my thesis was to quantify the effects of maternal state on maternally derived egg cortisol and determine whether this variation in egg cortisol impacts Chinook salmon offspring performance and fitness in a sex-specific way. I quantified within-female changes in maternal energetics and reproductive metrics that I linked to egg quality and ultimately embryo survival. I found egg cortisol increases with increasing maternal plasma cortisol, and increases further as plasma cortisol levels rise with each day that eggs are …

Host-Microbiome Interactions: Chinook Salmon (Oncorhynchus Tshawytscha) Gut Immune Function And Bacterial Community Composition, Farwa Zaib

Electronic Theses and Dissertations

Population divergence through selection can drive local adaptation, which has implications for effectively restoring declining and extirpated populations. Salmonid species provide an excellent model system to explore locally adapted traits as they are reproductively isolated and experience diverse environments. Here we focused on integrated immune function, which is affected by variation in host genetics and gene transcription as well as gut microbiome (bacterial community) variation. Furthermore, we explore interactions between host gut gene transcription levels and bacterial community composition to test co-adaptation of the host and its microbiome. In chapter 2, we utilized a factorial breeding design to determine the …

Assessing The Adaptive Capacity Of An Arctic Seabird To Increasing Frequency In Predation Risk From Polar Bears Using Behavioural And Physiological Metrics, Erica Anne Geldart

Electronic Theses and Dissertations

Predator-prey dynamics in the Arctic are being altered with changing sea-ice phenology. The increasing frequency of predation on colonial nesting seabird eggs by a rare predator - the polar bear (Ursus maritimus), is a consequence of bears shifting to terrestrial food resources through a shortened seal-hunting season. I study a colony of nesting common eiders (Somateria mollissima) on Mitivik (East Bay) Island, Nunavut, Canada, that is exposed to established nest predators such as arctic fox (Vulpes lagopus), but has recently experienced an increase in polar bear nest predation due to the bears’ lost on-ice hunting opportunities. Given eiders’ limited eco-evolutionary …

Multifaceted Environmental Enrichment In Industrial Fish Hatcheries: The Influence Of Enriched Rearing On The In-Situ Behaviour And Post-Stocking Success Of Juvenile Atlantic Salmon (Salmo Salar), Justine Elizabeth Mcadrews

Electronic Theses and Dissertations

Hatchery fish reared and stocked to sustain or restore wild populations often perform poorly in novel environments compared to their wild counterparts. To combat maladaptive hatchery-acquired traits environmental enrichment is an emerging tool used to provide ‘life skills training’ to hatchery fish prior to release. Through the application of simple yet multifaceted enrichment protocols in an industrial fish hatchery, this thesis aimed to demonstrate how enrichment could be applied to improve the ecological viability of stocked fish. At a provincially-run fish hatchery, a subgroup of juvenile Atlantic salmon (Salmo salar) were subject to 10 weeks of environmental enrichment …