Matching Items (14)
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Description

Globally, the incidental capture of non-target species in fisheries (bycatch) has been linked to declines of ecologically, economically, and culturally important marine species. Gillnet fisheries have especially high bycatch due to their non-selective nature, necessitating the development of new bycatch reduction technologies (BRTs). Net illumination is an emerging BRT that

Globally, the incidental capture of non-target species in fisheries (bycatch) has been linked to declines of ecologically, economically, and culturally important marine species. Gillnet fisheries have especially high bycatch due to their non-selective nature, necessitating the development of new bycatch reduction technologies (BRTs). Net illumination is an emerging BRT that has shown promise in reducing bycatch of marine megafauna, including sea turtles, cetaceans, and seabirds. However, little research has been conducted to understand the effects of net illumination on fish assemblages, including bony fish and elasmobranchs (i.e. sharks, rays, and skates). Here, I assessed a 7-year dataset of paired net illumination trials using four different types of light (green LEDs, green chemical glowsticks, ultraviolet (UV) lights, and orange lights) to examine the effects of net illumination on fish catch and bycatch in a gillnet fishery at Baja California Sur, Mexico. Analysis revealed no significant effect on bony fish target catch or bycatch for any light type. There was a significant decrease in elasmobranch bycatch using UV and orange lights, with orange lights showing the most promise for decreasing elasmobranch bycatch, resulting in a 50% reduction in bycatch rates. Analysis of the effects of net illumination on elasmobranch target catch was limited due to insufficient data. These results indicate that the illumination of gillnets may offer a practical solution for reducing fish bycatch while maintaining target catch. More research should be conducted to understand the effects of net illumination in different fisheries, how net illumination affects fisher profit and efficiency, and how net illumination affects fish behavior. Further optimization of net illumination is also necessary before the technology can be recommended on a broader scale.

ContributorsBurgher, Kayla Marie (Author) / Senko, Jesse (Thesis director) / Throop, Heather (Committee member) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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The purpose of this study is to spark a discussion for engineers and their firms to consider the impact of border barriers on wildlife. The focus of this study is to consider if or how engineers make those considerations, such as through design modifications. Barriers block wildlife migration patterns, disabling

The purpose of this study is to spark a discussion for engineers and their firms to consider the impact of border barriers on wildlife. The focus of this study is to consider if or how engineers make those considerations, such as through design modifications. Barriers block wildlife migration patterns, disabling them from life-sustaining resources. This is particularly important due to an increasing trend in habitat loss, urban development, and climate change. During literature analysis of border barrier impacts, and outreaching to relevant organizations and individuals, there was little to no public documentation or discussion from the engineering community found. Discussion that was found is included in this study, but the lack of connection between conservation and engineering professionals is eminently profound. Therefore, the analysis of studying engineering design considerations additionally studied the relationship between environmental and engineering professionals. Types of research included involves literature analysis of journal articles, reports, project plans for construction, and environmental laws pertinent to wildlife impact.
ContributorsMcMillin, Kaci (Author) / Karwat, Darshan (Thesis director) / Senko, Jesse (Committee member) / Engineering Programs (Contributor) / Environmental and Resource Management (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
Human consumption of sea turtle eggs, meat, and other products is considered to be a major threat to sea turtle populations worldwide. Declining populations are often attributed to anthropogenic pressures despite evident additional pressure from natural processes; however, depredation by natural or feral species such as raccoons, crabs, and dogs

Human consumption of sea turtle eggs, meat, and other products is considered to be a major threat to sea turtle populations worldwide. Declining populations are often attributed to anthropogenic pressures despite evident additional pressure from natural processes; however, depredation by natural or feral species such as raccoons, crabs, and dogs are often unknown. A popular tool for the conservation of marine turtle eggs is hatcheries, but their protection is limited by factors such as carrying capacity and timing or location of nests. The Rescue Center for Endangered Marine Species (CREMA) runs four sea turtle conservation projects on the nesting beaches of the Southern Nicoya Peninsula in Costa Rica, where the predominant nesting activity is from Olive Ridley turtles (Lepidochelys olivacea), followed by sporadic Green (Chelonia mydas), Leatherback (Dermochelys coriacea), and Hawksbill turtles (Eretmochelys imbricata). Two of these nesting projects are based in Costa de Oro and San Miguel, which are adjacent beaches divided by an estuary. Both projects use a hatchery where nests are usually relocated; however, when the hatchery is not available, nests are either relocated or left in situ at the beach. The aim of this study is to: 1) compare human harvest and depredation rates of nests relocated and left in situ. We reviewed data collected from 2012 to 2018 of nests relocated to a hatchery and left in situ at both nesting sites, and these data represent nesting conditions prior to relocation to a hatchery. We found that the nesting beach at Costa de Oro exhibits high rates of human harvest, which has decreased since the conservation project was established, while San Miguel exhibits comparatively low egg harvest but much higher depredation. Egg harvest in Costa de Oro decreases from approximately 50% of all nests in 2013 to 15% in 2018 while depredation on both beaches fluctuates year to year. Our results demonstrate that different pressures impact nesting beach success in the Southern Nicoya Peninsula along with natural threats, possibly due to contrasting community values and human populations. San Miguel has been protecting nests for over 20 years, whereas the Costa de Oro project only began in 2012. It also important to consider that depredation on the San Miguel nesting beach may be increased by human pressure such as in the case of domesticated animals, especially when the human population in San Miguel is consistently higher than in Costa de Oro. Persistence of depredation and human egg harvest alongside conservation efforts exhibit the prevalence of these pressures and suggest increased pressure if measures such as nightly patrols and hatchery protection were not utilized. We suggest a continuation of hatchery and patrol based conservation efforts as well as community outreach to attempt to merge cultural values with sea turtle conservation.
ContributorsReavis, Janie (Author) / Senko, Jesse (Thesis director) / Smith, Andrew (Committee member) / Barrett, The Honors College (Contributor)
Created2019-05
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As human populations continue to expand, interactions with wildlife are expected to increase due to destruction of land and global climate change threatening native habitats. Established areas of protection are becoming essential to species survival and biodiversity protection. National Parks (NP) are a globally ubiquitous method employed to protect wildlife

As human populations continue to expand, interactions with wildlife are expected to increase due to destruction of land and global climate change threatening native habitats. Established areas of protection are becoming essential to species survival and biodiversity protection. National Parks (NP) are a globally ubiquitous method employed to protect wildlife and habitats. Often NPs are mosaics of relatively small protected areas in a “sea” of human-dominated landscapes, and these remaining habitat “islands” are becoming essential to preventing species extinction. However, the establishment of a NP can lead to increased human-wildlife conflicts (HWC) and disenfranchisement of local communities, particularly along their borders. We conducted semi-structured interviews in six different countries to better understand the nature of HWCs at the borders of major NPs: (1) Khao Yai NP, Thailand; (2) Myall Lakes NP, Australia; (3) Chitwan NP, Nepal; (4) Kruger NP, South Africa; (5) Chingaza NP, Colombia, and (6) Yellowstone NP, United States. We evaluated affinity to wildlife, perception of conflicts, management success, and potential solutions at each park to better understand the global nature of HWCs.We also evaluated these data in relationship to the Human Development Index (HDI) to determine if there was a correlation between development and conflict issues. We found the intrinsic value of wildlife to not markedly differ between countries. Conflict was perceived as higher in the United States and Australia but was known to be of greater intensity in Nepal and South Africa. Management of NPs was well-regarded with a slight decrease from less-developed countries to more-developed countries, with solutions that were creative and unique to each region. Results appeared to be related to shifting baselines between countries and also to equivalency in a cross-cultural assessment. When these theories are taken into account, the complexity of HWCs globally is better understood. As our world continues to expand and NPs become some of the only contiguous native habitat and refuges for wildlife, it is important to understand the complex relationships occurring at the interface between natural and human communities and to explore effective solutions to these problems.
ContributorsRagan, Kinley Ann (Author) / Schoon, Michael (Thesis director) / Schipper, Jan (Committee member) / Senko, Jesse (Committee member) / School of Life Sciences (Contributor, Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Social behavior embodies a central tenet of biology yet social interactions remain fairly undocumented for marine turtles. Marine turtles have been studied extensively yet the importance and prevalence of social behaviors has largely been overlooked within the taxon as a whole. Through this project, new evidence suggests that marine turtles,

Social behavior embodies a central tenet of biology yet social interactions remain fairly undocumented for marine turtles. Marine turtles have been studied extensively yet the importance and prevalence of social behaviors has largely been overlooked within the taxon as a whole. Through this project, new evidence suggests that marine turtles, specifically Hawksbills, may not be as solitary as initially believed yet display a variety of social behaviors. These behaviors suggest that more complex social behaviors exist throughout the taxon and marine turtles may be more social than initially believed. These findings have important conservation management implications and encourages more research into turtle behavior.
ContributorsJohnson, Corinne Eva (Author) / Senko, Jesse (Thesis director) / Gaos, Alexander (Committee member) / School of Sustainability (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
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With human populations continuing to expand, encounters with wildlife become more frequent, and more people have the ability to go hunting. When it comes to top level predators, there have often been questions raised about the effects hunting has on their populations. Some speculate there are compensatory measures as a

With human populations continuing to expand, encounters with wildlife become more frequent, and more people have the ability to go hunting. When it comes to top level predators, there have often been questions raised about the effects hunting has on their populations. Some speculate there are compensatory measures as a result, others that hunting has an additive mortality effect. The purpose of this project was to do a literature review over the topic of hunting mountain lions in order to definitively determine what the effects of hunting are on their populations. It was concluded that hunting has a negative impact on mountain lion populations, having an additive effect on their mortality rate, reducing their genetic biodiversity, reducing their rate of emigration/immigration, and changing their population demographics.
ContributorsDaily, Austin (Author) / Senko, Jesse (Thesis director) / Bennett, Ira (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor) / Dean, W.P. Carey School of Business (Contributor)
Created2022-05
Description
Marine fisheries are a globally significant source of economic and food security, however high bycatch rates can threaten marine biodiversity putting both ecosystems and fisheries at risk for degradation. Although bycatch reduction technologies exist that can reduce the uptake of bycatch without significantly impacting target catch, bycatch rates remain high.

Marine fisheries are a globally significant source of economic and food security, however high bycatch rates can threaten marine biodiversity putting both ecosystems and fisheries at risk for degradation. Although bycatch reduction technologies exist that can reduce the uptake of bycatch without significantly impacting target catch, bycatch rates remain high. To understand the factors that affect fishers’ change readiness we reviewed 15 interview-based studies assessing fishers perspectives on bycatch and bycatch reduction strategies. In sum, the perspectives of 1,991 fishers were assessed in these studies across 10 different countries from 2006-2023. One key finding that arose was the potential importance of agency. This factor closely relates to change readiness and was identified as an essential component for effective bycatch reduction. Additionally, it was discovered that the kind of proposed strategy is important. Bycatch reduction methods that are equally effective in capturing target catch while reducing non-target catch and are accessible are more likely to have favorable responses from fishers. Agency and change readiness are interconnected and may be influenced by a variety of factors such as income, education, experience, and beliefs/values. Incentives and education/engagement programs may be useful in fostering fishers’ willingness for change and improving the efficacy of bycatch reduction strategies.
ContributorsHendrix, Gabrialla (Author) / Senko, Jesse (Thesis director) / Vargas, Cindy (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2024-05
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Description
Mealworms (Tenebrio molitor), the larval stage of yellow mealworm beetles, are a popular feeder insect for birds, amphibians, reptiles, fish, and even human populations throughout the world. As such, the goal of this work was to understand how the diet of mealworms impacts their nutritional quality as variations in quality

Mealworms (Tenebrio molitor), the larval stage of yellow mealworm beetles, are a popular feeder insect for birds, amphibians, reptiles, fish, and even human populations throughout the world. As such, the goal of this work was to understand how the diet of mealworms impacts their nutritional quality as variations in quality can impact the animals (and humans) that consume them. In this study, 500 mealworms were divided among each of the following substrates designed to model food sources available in urban versus rural, more natural areas: 100% wheat germ (control); 100% Styrofoam; mixture of soil, grasses, and leaves from urban lawns; a mixture of soil, grasses and leaves from rural lawns; 50% mixture of wheat germ + carrots; natural fertilizer; or fertilizer with weed killer. The mealworms were maintained at room temperature and the diets were replaced bi-weekly to prevent spoilage and to remove mealworm waste. Once a week for three weeks, mealworms were sampled from each substrate and frozen at -20°C. After 3 weeks, mealworms housed in wheat germ + carrots weighed significantly more than all other groups (p<0.05), whereas those housed in Styrofoam or urban lawn substrates weighed significantly less at week 3 as compared to week 1 (p<0.01). The urban lawn substrate resulted in greater molting and contained the highest number of pupae, but also the greatest mortality among the substrates. The Bradford method measured the total protein content of mealworms homogenized in phosphate-buffered saline. Mealworms maintained on wheat germ had significantly greater total protein content as compared to mealworms transitioned to any other diet (p<0.05). So, compared to wheat germ, urban foods generally reduced protein, total sugars, and crude fat, although they also decreased oxidized lipoproteins. Urban lawn had lower oxidized lipoprotein content than wheat germ, but levels were higher compared to wheat germ with carrots and natural fertilizer. In addition, urban foods generally increase the water content in mealworms. Urban foods were not much different from rural lawns as no there was difference between urban and rural lawns. Differences in body mass and total protein support the hypothesis that mealworms' nutritional quality is altered by ingesting urban substrates. These data suggest that mealworms (and potentially other insects) in cities may be exposed to food substrates that result in less nutritional value than those living in more natural areas as mimicked by the rural lawn substrates and wheat germ control, although they may be higher in water content.
ContributorsLockett, Rory Earle (Author) / Sweazea, Karen (Thesis advisor) / Deviche, Pierre (Committee member) / Senko, Jesse (Committee member) / Arizona State University (Publisher)
Created2024
Description

Due to what is known as the “biologically desert fallacy” and the pervasive westernized ideal of wilderness that has influenced widespread American Conservation culture for millennia, urban areas have long been deemed as areas devoid of biodiversity. However, cities can contribute significantly to regional biodiversity and provide vital niches for

Due to what is known as the “biologically desert fallacy” and the pervasive westernized ideal of wilderness that has influenced widespread American Conservation culture for millennia, urban areas have long been deemed as areas devoid of biodiversity. However, cities can contribute significantly to regional biodiversity and provide vital niches for wildlife, illuminating the growing awareness that cities are crucial to the future of conservation and combating the global biodiversity crisis. In terms of the biodiversity crisis, bats are a relevant species of concern. In many studies, different bat species have been broadly classified according to their ability to adapt to urban environments. There is evidence that urban areas can filter bat species based on traits and behavior, with many bats possessing traits that do not allow them to live in cities. The three broad categories are urban avoiders, urban adapters, or urban exploiters based upon where their abundance is highest along a gradient of urban intensity. A common example of an urban exploiter bat is a Mexican Free-tailed bat, which can thrive and rely on urban environments and it is found in the Phoenix Metropolitan area. Bats are important as even in urban environments they play vital ecological roles such as cactus pollination, insect management, and seed dispersal. Bat Crazy is a thesis project focused on urban enhancement and the field of urban biodiversity. The goals of this thesis are to observe how bio-conscious urban cities that work to promote species conservation can serve as a positive tool to promote biodiversity and foster community education and engagement for their urban environment.

ContributorsKaiser, Nicole (Author) / Senko, Jesse (Thesis director) / Angilletta, Michael (Committee member) / Lynch, John (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2023-05
Description

The Arizona Board of Education decides the science curricula for students K-6. The standards lack an in depth knowledge of marine life, marine science, ocean conservation, and more related topics. Through interviews with teachers, faculty, and research on ocean literacy and coral reefs, My Coral Reef Booklet assembles various learning

The Arizona Board of Education decides the science curricula for students K-6. The standards lack an in depth knowledge of marine life, marine science, ocean conservation, and more related topics. Through interviews with teachers, faculty, and research on ocean literacy and coral reefs, My Coral Reef Booklet assembles various learning activities to cater to students from a variety of education, financial and impairment backgrounds. My Coral Reef Booklet addresses coral reef basics and how students can play their part in coral reef conservation despite their location.

ContributorsHynds, Janna (Author) / Hedges, Craig (Thesis director) / Senko, Jesse (Committee member) / Barrett, The Honors College (Contributor) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor)
Created2023-05