Terrestrial and Aquatic Ecology Commons^™

Scaling And Ecological Relationships In The Visual Ecology Of Sharks, Brianna Hall

College of Graduate Studies: Theses & Dissertations

Adaptations of visual systems, such as acuity, sensitivity, and eye size can be used to infer the relative importance of vision to an organism. The high metabolic cost of visual system development and maintenance suggests that large relative eye size (as it relates to body length) may have a significant ecological or evolutionary role. Elasmobranchs are morphologically diverse and inhabit a wide range of marine and freshwater niches. As energetic and ecological demands shift over time, several species occupy different predatory niches across their lifetime, yielding a large array of visual habitats. Additionally, eye size changes with body length allometrically, …

Surfacant Contamination Alters Freshwater Phytoplankton Community Composition, William H. Hodge

College of Graduate Studies: Theses & Dissertations

Pollution from cleaning and personal care products enter freshwater systems and have the potential to alter phytoplankton abundance and diversity. Alkyl polyglucoside (APG), a widely used foaming agent in detergents, decreases phytoplankton abundance, but whether sensitivity to APG is affected by taxonomic identity and/or the presence of competitors is unclear. Establishing taxon-specific responses to APG is important, because taxa differ in nutritional quality and palatability for zooplankton grazers.

Chapter one describes comparisons between how individual phytoplankton communities respond to the same range of APG concentrations to test hypotheses that: 1) chemical concentration determines how individual taxa respond to APG; 2) …

Problems With Basing Insect Ethics On Individuals’ Welfare, Susana Monsó, Antonio J. Osuna-Mascaró

Animal Sentience

In their target article, Mikhalevich & Powell (M&P) argue that we should extend moral protection to arthropods. In this commentary, we show that there are some unforeseen obstacles to applying the sort of individualistic welfare-based ethics that M&P have in mind to certain arthropods, namely, insects. These obstacles have to do with the fact that there are often many more individuals involved in our dealings with insects than our ethical theories anticipate, and also with the fact that, in some sense, some insects count as more than an individual and, in another sense, they sometimes count as less than an …

Lessons From Miniature Brains: Cognition Cheap, Memory Expensive (Sentience Linked To Active Movement?), Giorgio Vallortigara

Animal Sentience

Studies on invertebrate minds suggest that the neural machinery for basic cognition is cheap, and that bigger brains are probably associated with greater memory storage rather than more advanced cognition. Sentience may be linked to feedforward mechanisms (Reafferenzprinzip) that allow organisms with active movement to distinguish active and passive sensing. Invertebrates may offer special opportunities for testing these hypotheses.

Recovery Of Benthic Macroinvertebrate Communities After Restoration In Two Intensively Mined Watersheds, Brian R. Gordon

Graduate Theses, Dissertations, and Problem Reports (ETD)

As the body of literature supporting watershed-scale restoration projects continues to grow, there is need for a greater understanding of the underlying mechanisms that drive it. With data spanning ten years capturing pre- and post-restoration benthic macroinvertebrate communities in two distinct watersheds of West Virginia, we seek to contribute to the developing pool of knowledge regarding these dynamics. Sites were laid out prior to remediation in such a manner as to capture the spectrum of water quality conditions present, these are divided into three treatment types: reference, treated, and abandoned mine drainage (AMD). Our objectives were to: 1) determine if …

Avian And Salamander Response To Young Forest Management In West Virginia, Eric L. Margenau

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation focuses on the effects of various young forest habitat management techniques on the avian and salamander community in West Virginia. Wildlife species associated with the nascent stage of forest succession are experiencing precipitous population declines throughout much of the eastern United States due to decreases in the amount of young forest area which have been brought on by changes in disturbance regimes over the past century. As a result, the need to find novel approaches for creating young forest habitats to sustain young forest wildlife populations is necessary. However, young forest habitat creation often negatively affects species that …

Tree Growth And Water Use Efficiency During The Twentieth Century: From Global Trends To Local Drivers, Justin Michael Mathias

Graduate Theses, Dissertations, and Problem Reports (ETD)

The frequency and severity of extreme environmental conditions will continue to increase under global environmental change. How terrestrial plants respond to prolonged, and often novel environmental stressors, will have profound impacts on, and feedbacks with, the Earth climate system at local to continental scales. Central to these feedbacks are plant stomata, actively regulated pores on the leaves of plants that act as a control valve over the fluxes of carbon dioxide (CO₂) into the leaf during photosynthesis and water vapor (H₂O) out of the leaf during transpiration. Importantly, changes in stomatal aperture do not affect the …

Impact Of Uk Sport Fishing On Fish Welfare And Conservation, Tim Q. Holmes

Animal Sentience

Sport fishing or angling is the capture of fish for recreation or competition, i.e., for entertainment. Contrary to the claims of Key (2016), there is good evidence that fish feel pain and have the capacity for self-awareness (Sneddon et al., 2018; Woodruff, 2017). Wild fish experience a variety of adverse conditions in nature that can harm their welfare, but this does not justify humans intentionally inflicting such conditions on fish solely for our pleasure. This commentary summarises the many ways fish suffer harm to their welfare as a result of sport fishing. There are also discussions on associated activities that …

Ethical Considerations For Invertebrates, Scarlett R. Howard, Matthew R.E. Symonds

Animal Sentience

Mikhalevich & Powell (2020) have built on the discussion about which species deserve inclusion in animal ethics and welfare considerations. Here, we raise questions concerning the assessment criteria. We ask how to assess different species for their ability to fulfill the criteria, which criteria are most important, how we quantify them (absolute or on a continuum), and how non-animals such as fungi and plants fit into this paradigm.

Sentience In Evolutionary Context, Jon Mallatt, Todd E. Feinberg

Animal Sentience

We appreciate the goals of Mikhalevich & Powell (M&P) and largely agree with their conclusions but we differ on some of their definitions and terms. Affects (emotional feelings) should be part of sentience. Although the evidence presented for insect sentience is strong, we list some of the counterevidence that should be considered. Our own research supports M&P’s choice of arthropods, cephalopods, and vertebrates as the only sentient organisms with moral status.

The Wholeness Of Nature, Marthe Kiley-Worthington

Animal Sentience

The target article outlines various positions on conservation and preservation but ignores practical considerations of management since there is no wild habitat left. Population controls, either human or nonhuman mammals, are not discussed. The suggestions for legal changes are vague and will require much more thinking about how to integrate animal welfare with wildlife conservation concerns. “Freedoms” as outlined in the human bill of rights might help with decision making for improving animal welfare. Other commentators have made anthropocentric judgements concerning animal welfare, ignoring the importance of developing other ways of seeing and understanding the “multiplicity within unity,” combining empirical …

Gulf Coast Marine Laboratories Past, Present And Future, Donald F. Boesch

Gulf and Caribbean Research

I spent my nearly 50—year career in marine science working at marine laboratories, most of that as a chief executive officer. So, it is appropriate that my reflections are about marine laboratories, rather than my own science. After relating my career course, I turn my attention to the history and development of marine laboratories along the U.S. coast of the Gulf of Mexico (GOM). Surprisingly, the region’s first laboratory was actually constructed in 1903 at Cameron, LA, but operated less than a decade before closing. It was not until after World War II that the university—affiliated marine laboratories of today …

Impacts Of Transportation Infrastructure On Water Quality, Sediment Loads, And Fishing Opportunities In The Gwich’In Settlement Area, Northwest Territories, Matthew Teillet

Theses and Dissertations (Comprehensive)

The addition of gravel sediment to build ferry landings on the Peel and Mackenzie Rivers has been an ongoing concern for the Gwich’in communities of Fort McPherson and Tsiigehtchic that depend on the rivers for their livelihoods. Specifically, there are concerns that gravel from ferry landings is degrading water quality, harming fishing opportunities, and altering river morphology downstream. Previous reports concluded that ferry operations were not impacting downstream ecology. However, past studies had methodological shortcomings and community concerns about the ferry landings remain. To study the impact of the gravel landings on water quality, I utilized a multidisciplinary study design …

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.

Stone-Stacking As A Looming Threat To Rock-Dwelling Biodiversity, Ricardo Rocha, Paulo A. V. Borges, Pedro Cardoso, Mirza Dikari Kusrini, José Luis Martín-Esquivel, Dília Menezes, Mário Mota-Ferreira, Sara F. Nunes, Inês Órfão, Catarina Serra-Gonçalves, Manuela Sim-Sim, Pedro Sepúlveda, Dinarte Teixeira, Anna Traveset

Human–Wildlife Interactions

This letter to the editor describes the surge of “photo-friendly” stacks of stones as an emerging tourism-associated threat to rock-dwelling biodiversity.

A Tale Of Two Cervids: Habitat Selection And Spatial Ecology Of Roosevelt And Tule Elk In California, Adam S. Mohr

Cal Poly Humboldt theses and projects

California’s Roosevelt (Cervus canadensis rooseveltii) and tule elk (C. c. nannodes) populations have experienced a remarkable recovery after over-hunting and habitat loss nearly extirpated them from the state. Greater clarity of Roosevelt and tule elk habitat selection patterns would help managers continue to effectively support the recovery of these two iconic subspecies. As the manner in which elk populations balance their competing resource needs is unique to each population (Skovlin et al. 2002), I have examined Roosevelt and tule elk habitat selection patterns in separate analyses and present these results in independent chapters. In both cases, …

Changes In Prey Mortality: The Efects Of Multiple Predators And Temperature On California Mussels, Wesley Hull

Cal Poly Humboldt theses and projects

Organisms serve as prey to a variety of predators within natural systems, detecting threats through physical and chemical means. While predator feeding behavior is also affected by the presence of other predators, it is unclear whether differing modes of detection have similar effects on predator feeding behavior. In rocky intertidal zones in northern California, the California mussel (Mytilus californianus) is a competitively dominant foundation species consumed by a variety of predators. I quantified the individual and combined effects of ochre star (Pisaster ochraceus) and rock crab (Romaleon antennarium) predation on mussels by implementing mussel …

Impacts Of Flow Releases On Invertebrate Drift And Juvenile Chinook Salmon (Oncorhynchus Tshawytscha) Diet On The Trinity River Below Lewiston Dam, Thomas R. Starkey-Owens

Cal Poly Humboldt theses and projects

Benthic macroinvertebrate (BMI) drift, species composition and abundance are specific to local hydrologic and habitat conditions, which can restrict or enhance availability to salmonids as a food resource. Currently, a knowledge gap exists on the Trinity River (northern California) in how flow releases from Lewiston Dam potentially impact BMI drift and feeding opportunities for juvenile salmonids. Samples of BMIs from drift, benthos, and diets of juvenile Chinook salmon (Oncorhynchus tshawytscha) were collected from two sites in the upper Trinity River February-April 2018, during stable flow conditions (~8 ) and two increased flow conditions peaking at ~50 . Chironomidae …

Spatiotemporal Partitioning Of Mammalian Mesopredators In Response To Drought And Urbanization In California's Central Valley, Chad W. Moura

Cal Poly Humboldt theses and projects

Mammalian mesopredators commonly associated with human dominated landscapes often exhibit generalist diets, behavioral plasticity, and relatively high reproductive rates. Because of this wide range of adaptive traits, ecologists have been speculative of what conditions may drive species to change their activity and behavior to avoid or mitigate against resource competition, intraguild predation, and human disturbance. I investigated a community of common mesopredators within the Sacramento Metropolitan Area of California’s Central Valley to address whether species are spatially and/or temporally partitioning due to a defacto apex predator, coyotes (Canis latrans), and humans alongside large landscape altering disturbances: urbanization and drought. I …

American Alligator (Alligator Mississippiensis) Ecology Within Human-Dominated Landscapes, Eli R. Beal

UNF Graduate Theses and Dissertations

Urbanization is an ever-increasing threat to wildlife and their habitats, yet research has been limited to a small number of taxa. The American alligator (Alligator mississippiensis) is an apex predator that has surprisingly received minimal attention within urban areas. To investigate the potential effects of urban land use on spatial ecology, we conducted surveys of relative alligator abundance in nine tributaries surrounding the St. Johns River. We used these data to explore the potential effects of urban development on alligator spatial distribution and habitat selection. At the coarse scale, we found no correlation between percent developed land and …

Assessing The Feasibility Of Freshwater Mussel Restoration In Urban Streams., John-Reid Ryan

Theses and Dissertations

Abstract

The main objective of this study was to determine whether introduced freshwater mussels (Alewife floater, Utterbackiana implicata) can survive and grow in urban streams in the James River watershed. A secondary objective was to assess differences in U. implicata survival and growth of in the context of differing water quality and food resource conditions among three urban sites and three rural sites. Results from this study show large differences in growth and survivorship of mussels across sites. Higher survivorship was observed among mussels stocked into rural streams (35% and 44%) in comparison to urban streams (3%, 6% and 14%). …

Stimulated Growth Response To Sand Burial Of A Coastal Shrub, D. Nicole Keller

Theses and Dissertations

Drivers of vegetation zonation on barrier islands are complex and interconnected. Sand burial is a strong driver in dynamic coastal systems, especially in the foredune community. However, it is not well understood how burial impacts the interdunal swales communities and it is especially difficult to separate the effects of burial from salinity. Climate change is altering the frequency of overwash events as well as expanding the range of the native shrub, Morella cerifera, on the Virginia barrier islands. To accurately forecast island response to climate change it is important to understand how the shrub responds to sand burial. Juvenile …

The Ecological Function Of Intertidal Seagrass For Sediment Entrapment On Middle Bank Shoal, Penang, Awang Nur Asilah

Student Works (2020-2029)

Application of seagrass in eco-engineering for sustainable coastal protection requires a deeper understanding of seagrass functions for sediment entrapment. Knowledge gaps on the influence of intertidal seagrass in trapping sediments raised two main questions in this study; (1) what is the relationship between intertidal seagrass meadow structure and trapped sediment? and (2) which part of the intertidal seagrass meadow structure best explains the variability of trapped sediment? To answer these questions, seagrass shoot density, Leaf Area Index (LAI), and total aboveground biomass were used as predictors for sediments deposition rate on Middle Bank Shoal. Three seagrass species were found; Enhalus …