Matching Items (23)
Description
Biodiversity is required to guarantee proper ecosystem structure and function. However, increasing anthropogenic threats are causing biodiversity loss around the world at an unprecedented rate, in what has been deemed the sixth mass extinction. To counteract this crisis, conservationists seek to improve the methods used in the design and implementation of protected areas, which help mitigate the impacts of human activities on species. Marine mammals are ecosystem engineers and important indicator species of ocean and human wellbeing. They are also disproportionally less known and more threatened than terrestrial mammals. Therefore, surrogates of biodiversity must be used to maximize their representation in conservation planning. Some of the most effective surrogates of biodiversity known have only been tested in terrestrial systems. Here I test complementarity, rarity, and environmental diversity as potential surrogates of marine mammal representation at the global scale, and compare their performance against species richness, which is the most popular surrogate used to date. I also present the first map of marine mammal complementarity, and assess its relationship with environmental variables to determine if environmental factors could also be used as surrogates. Lastly, I determine the global complementarity-based hotspots of marine mammal biodiversity, and compare their distributions against current marine protected area coverage and exposure to global indices of human threats, to elucidate the effectiveness of current conservation efforts. Results show that complementarity, rarity, and environmental diversity are all efficient surrogates, as they outcompete species richness in maximizing marine mammal species representation when solving the minimum-set coverage problem. Results also show that sea surface temperature, density, and bathymetry are the top environmental variables most associated with complementarity of marine mammals. Finally, gap analyses show that marine mammals are overall poorly protected, yet moderately exposed to hotspots of cumulative human impacts. The wide distribution of marine mammals justify global studies like the ones here presented, to determine the best strategy for their protection. Overall, my findings show that less popular surrogates of biodiversity are more effective for marine mammals and should be considered in their management, and that the expansion of protected areas in their most important habitats should be prioritized.
ContributorsAstudillo-Scalia, Yaiyr (Author) / Albuquerque, Fabio (Thesis advisor) / Deviche, Pierre (Thesis advisor) / Polidoro, Beth (Committee member) / Kellar, Nicholas (Committee member) / Arizona State University (Publisher)
Created2019
Description
Marine conservation faces the unique challenge of trying to assess and protect species, like sharks, that have long migration tracks and are often targeted by fishing vessels in open and international waters. Over the last two decades, several large predatory shark populations have been greatly depleted despite local and international organizations designed to help regulate and prevent predator removal to avoid disturbing the food web those sharks balance (Myers, Baum, Shepherd, Powers, & Peterson, 2007). Forensic science is a powerful tool that could give shark conservation efforts an edge on identifying shark species currently being targeted by unsustainable fisheries in international waters. Allowing offenders who break international conservation laws to be prosecuted for their crimes. Unfortunately, this unique and powerful tool has not been given the opportunity to be utilized as it should be. An overview of national and international agencies, organizations, and laws disclosed a strong foundation for wildlife conservation. However, current international organizations and laws that govern international waters leave much to be desired in regards to protecting shark species that are threatened due to being popular targets for fishing vessels. This paper examines the level of forensic science involvement in shark conservation efforts through a literature review, revealing a severe lack of real-life application of forensic science to marine conservation cases. Current issues that marine wildlife forensic science encounters while attempting to increase forensic capability. And finally, presenting proposals for the future, and new challenges, which aim to strengthen the relationship between forensic science and marine conservation.
ContributorsParker, Jamie Caitlin (Author) / Kobojek, Kimberly (Thesis director) / Polidoro, Beth (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
As threats to Earth's biodiversity continue to evolve, an effective methodology to predict such threats is crucial to ensure the survival of living species. Organizations like the International Union for Conservation of Nature (IUCN) monitor the Earth's environmental networks to preserve the sanctity of terrestrial and marine life. The IUCN Red List of Threatened Species informs the conservation activities of governments as a world standard of species' risks of extinction. However, the IUCN's current methodology is, in some ways, inefficient given the immense volume of Earth's species and the laboriousness of its species' risk classification process. IUCN assessors can take years to classify a species' extinction risk, even as that species continues to decline. Therefore, to supplement the IUCN's classification process and thus bolster conservationist efforts for threatened species, a Random Forest model was constructed, trained on a group of fish species previously classified by the IUCN Red List. This Random Forest model both validates the IUCN Red List's classification method and offers a highly efficient, supplemental classification method for species' extinction risk. In addition, this Random Forest model is applicable to species with deficient data, which the IUCN Red List is otherwise unable to classify, thus engendering conservationist efforts for previously obscure species. Although this Random Forest model is built specifically for the trained fish species (Sparidae), the methodology can and should be extended to additional species.
ContributorsWoodyard, Megan (Author) / Broatch, Jennifer (Thesis director) / Polidoro, Beth (Committee member) / Mancenido, Michelle (Committee member) / School of Humanities, Arts, and Cultural Studies (Contributor) / School of Mathematical and Natural Sciences (Contributor) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The International Union for Conservation of Nature's Red List of Threatened Species is the most comprehensive and objective global approach to evaluate the conservation status of species by categorizing species based on relative extinction risk. For the Global Muranidae IUCN Red List assessment, all known, taxonomically valid species of Muraenidae were assessed for their extinction risk using the IUCN Red List Global Categories and Criteria. Of all 208 Muraenidae species, it was concluded that 86% of species qualified for Least Concern, 13% of species are Data Deficient, and 1% of species qualified for a threatened category. Channomuraena bauchotae is listed as threatened under VU D2 and Gymnothorax parini qualified for VU B2ab(iii). This study will have brought the International Union for the Conservation of Nature one step closer to their goal of conducting Red List assessments of all the world's species(not including microorganisms). Future implications of this study may include future monitoring of key habitat areas and species or conducting further research to gain a more in depth understanding of the life history and threats to Muraenidae.
ContributorsLaurence, Paige Marie (Author) / Polidoro, Beth (Thesis director) / Ralph, Gina (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Consumption of seafood poses a substantial threat to global biodiversity. Chemical contamination found in both wild-caught and farmed seafood also presents significant health risks to consumers. Flame retardants, used in textiles, upholstery, plastics, and other products to reduce risk of fire-related injury, are of particular concern as they are commonly found in the marine environment and permeate the tissues of fish that are sold for consumption via multiple pathways. The widespread issue of fishery collapse could be alleviated by demonstrating to stakeholders that many unsustainable fish stocks are also unhealthy and mutually disadvantageous for both human consumers and the environment. To thoroughly investigate the confounding factors and contradictory signals enmeshed in the relationship between ecologically sustainable fisheries and flame retardant contamination, I examined the biological characteristics of regional fish stocks which drive both contamination and perceived sustainability. I found that the biological and spatial aspects of commonly consumed aquatic and marine species best predict contamination when compared with various indices of sustainability. My results confirm that knowledge of flame retardant toxicity will become increasingly more important to consumers because a high percentage of global populations rely on coastal seafood for subsistence, and although dispersal of chemical contamination is still a poorly understood phenomenon, fish harvested closer to land are likely to contain higher concentrations of potentially harmful chemicals. Because some of the same biological traits which facilitate the uptake of chemicals also contribute to how a species responds to fishing pressures, concern for private health increases public consideration for the conservation of species at risk.
ContributorsNoziglia, Andrea (Author) / Gerber, Leah (Thesis advisor) / Abbott, Joshua (Committee member) / Polidoro, Beth (Committee member) / Arizona State University (Publisher)
Created2015
Description
The Philippines relies on a vast biodiversity of fishes as a staple food, but like many countries around the globe, experiences severe “leakages” of contaminants and pollutants in the environment. In order to better understand the relationship between environmental pollutants and public health, this research project measured the concentration of pollutants in a commonly consumed local fish (Siganus fuscescens), and then evaluated the potential health risks of eating this fish based on estimated average consumer weight and consumption levels. Fish sampled from four different sites located in Negros Oriental, Philippines were analyzed for organic contaminants using gas chromatography and mass spectroscopy. Pollutants quantified included polycyclic aromatic hydrocarbons (PAHs), pesticides, phthalates, and polychlorinated biphenyl (PCBs). Across the four study sites, fishes from Manjuyod showed the highest frequency of detection of different pollutants. However, phthalates and PAHs were found in similar concentrations in all four sites, with fishes from Dumaguete showing the highest level of PCBs compared to the other sampled sites. The U.S. Environmental Protection Agency’s guide for fish contaminants pinpoints several health risks associated with the chronic ingestion of these contaminants. Based on estimated average body weights of Filipino adult men, adult women, and children, and various consumption levels, people who eat the fish at or above the national average consumption level may be at increased risk for chronic health outcomes, such as cancer and/or other adverse effects. Specifically, due to the high concentration of PCBs in Dumaguete, selected populations who eat local fish from this site may be at higher risk than the citizens who eat the fish from other sites at similar consumption rates. These results can help to inform local and national policies on water quality, waste disposal, and fish consumption advisory programs.
ContributorsMolino, Eryka J (Author) / Polidoro, Beth (Thesis director) / Bucol, Lilibeth (Committee member) / School of Life Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This thesis utilizes GIS mapping to analyze the severity of four threats: ocean acidification, sea surface temperature, artisanal fishing, and destructive fishing, in conjunction with coral species distribution. This project produced maps that depicts each of these threats and shows the distribution of its severity. Compiling this data we can see that ocean acidification is the most pressing threat in the Caribbean to coral and that neither type of fishing really has a large effect. A species named Madracis carmabi is also flagged to be of particular concern as it is severely threatened by both ocean acidification and sea surface temperature.
ContributorsStats, Anastasia Katherine (Author) / Polidoro, Beth (Thesis director) / Sulikowski, James (Committee member) / School of Mathematical and Natural Sciences (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Silicone wristbands consist of a porous surface with the potential to sequester organic contaminants in the environment. Their properties allow for them to be used as a novel sampling approach to assessing personal human exposure to environmental contaminants. The purpose of the study was to understand the effectiveness of silicone wristbands as sampling devices. This was addressed by identifying and quantifying pesticide recovery from exposed wristbands. Triplicate groups of wristbands were dosed with 37 persistent organochlorine or organophosphate pesticides and then extracted to estimate human exposure through recovery. Results suggest that silicone wristbands have the potential to absorb a number of pesticides and organic contaminants, although at varying rates and quantities. As more uptake and sequestration rates can be established, wristbands have the potential to serve as indicators of human exposure to a variety of pesticides and other chemical groups at trace amounts.
ContributorsGonzalez, Melissa (Author) / Polidoro, Beth (Thesis director) / Marshall, Pamela (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2021-12
Description
The intramandibular joint (IMJ) in Helostoma temminckii, also known as kissing gourami, is located in the lower jaw at the articulation of the dentary and angular-articular bones. These fish are known for a ‘kissing’ behavior, facilitated by the IMJ, which allows the jaws to protrude and rotate making the mouth appear to look like pursed lips. The IMJ has independently evolved in the teleost lineage multiple times, and the mechanics are slightly different in each lineage. In kissing gourami, there are no muscular connections to the region of the lower jaw anterior to the IMJ, thus the IMJ is something of an enigma in terms of how it is mobilized during feeding, and moreover returned to a resting state after feeding. High-speed video was used to examine lateral expansion particularly in the regions of the intramandibular joint (IMJ) and the quadratomandibular (QMJ) joint. Individuals were filmed from a lateral and ventral view simultaneously during food capture. From the data, it appears that the expansion at the IMJ contributes to lateral expansion of the head during food capture. Lateral expansion at the location of the IMJ appears to occur in tandem with rotation about that joint; however, lateral expansion in this species is also rather slight due to their extremely rigid heads.
ContributorsLevy, Taylor (Author) / Ferry, Lara (Thesis advisor) / Gibb, Alice (Committee member) / Polidoro, Beth (Committee member) / Arizona State University (Publisher)
Created2022
Description
The Gulf of Mexico (or “Gulf”) is of critical significance to the oil and gas industries’ offshore production, but the potential for accidental petrochemical influx into the Gulf due to such processes is high; two of the largest marine oil spills in history, Pemex's Ixtoc I spill (1979) and British Petroleum's (BP) Deepwater Horizon (2010), have occurred in the region. However, the Gulf is also of critical significance to thousands of unique species, many of which may be irreparably harmed by accidental petrochemical exposure. To better manage the conservation and recovery of marine species in the Gulf ecosystem, a Petrochemical Vulnerability Index was developed to determine the potential impact of a petrochemical influx on Gulf marine fishes, therein providing an objective framework with which to determine the best immediate and long term management strategies for resource managers and decision-makers. The resulting Petrochemical Vulnerability Index (PVI) was developed and applied to all bony fishes and shark/ray species in the Gulf of Mexico (1,670 spp), based on a theoretical petrochemical vulnerability framework developed by peer review. The PVI for fishes embodies three key facets of species vulnerability: likelihood of exposure, individual sensitivity, and population resilience, and comprised of 11 total metrics (Distribution, Longevity, Mobility, Habitat, Pre-Adult Stage Length, Pre-Adult Exposure; Increased Adult Sensitivity Due to UV Light, Increased Pre-Adult Sensitivity Due to UV Light; and Abundance, Reproductive Turnover Rate, Diet/Habitat Specialization). The resulting PVI can be used to guide attention to the species potentially most in need of immediate attention in the event of an oil spill or other petrochemical influx, as well as those species that may require intensive long-term recovery. The scored relative vulnerability rankings can also provide information on species that ought to be the focus of future toxicological research, by indicating which species lack toxicological data, and may potentially experience significant impacts.
ContributorsWoodyard, Megan (Author) / Polidoro, Beth (Thesis advisor) / Saul, Steven (Thesis advisor) / Matson, Cole (Committee member) / Arizona State University (Publisher)
Created2020