Current Search: UWF Theses (x) » Microplastics (x)
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- Title
- Characterization of calpain activity in response to microplastic exposure in Donax variabilis.
- Author
- Schroeder, Hans Erik
- Abstract/Description
-
Coquina clams (Donax variabilis) are small multicolored bivalve mollusks that inhabit the intertidal zones of various southeastern beaches along the eastern coast of the United States where they are in great abundance and an essential part of the beach ecosystem. Because they are filter-feeders that are exposed to environmental hazards, Donax variabilis populations are a sign of the beach's ecological health. Potentially, this mollusk may be effective as a "canary in a coal mine" if...
Show moreCoquina clams (Donax variabilis) are small multicolored bivalve mollusks that inhabit the intertidal zones of various southeastern beaches along the eastern coast of the United States where they are in great abundance and an essential part of the beach ecosystem. Because they are filter-feeders that are exposed to environmental hazards, Donax variabilis populations are a sign of the beach's ecological health. Potentially, this mollusk may be effective as a "canary in a coal mine" if biological changes are easily measurable that may be sensitive to important environmental changes. One such mechanism are the calpains. Calpains are Ca2+-dependent cysteine proteases that are expressed in nearly all eukaryotes, but have rarely been studied in invertebrates like the Coquina clam. It is well established that calpains are essential to cellular homeostasis and have been implicated in a multitude of cellular functions, such as apoptosis and cellular stress. In recent years, microplastics, plastic particles that range in size but are less than 5mm, have become a serious hazard to the environment. Accumulation of microplastics have only recently been recognized to be harmful to marine organisms that ingest them and cause tissue damage on a cellular and subcellular level that may alter calpain activity. Although Coquina clams are in great abundance on the beaches and their ecological patterns have been studied thoroughly, the cellular and subcellular processes of the Coquina clam have not been studied extensively. Specifically, it is not understood how calpains function under normal conditions or how these molecules would be affected due to large ecological impacts in the form of contaminants like microplastics. It is our contention that Coquina clams can be used as a bioindicator of healthy beaches and aid in assessing the presence or absence of pollutants such as microplastics that can occur in the ecosystem, using cellular and subcellular processing by calpains as a measure.
Show less - Date Issued
- 2019, 2019
- Identifier
- 1153167661, WFE0000699
- Format
- Document (PDF)
- Title
- Epigenetic effects of microplastics exposure on the common mysid shrimp, americamysis bahia.
- Author
- Prior, Jack Hamilton
- Abstract/Description
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Microplastics are publicly recognized as a ubiquitous issue of environmental concern in aquatic systems. Primary consumers of microplastics are often zooplankton of biological and commercial importance, including the mysid shrimp, Americamysis bahia. In the presence of environmental stressors, gene expression may be altered without changing DNA sequences. This can occur through methylation of the DNA, in which a methyl group binds to nucleotide base pairs, most commonly cytosine. In this...
Show moreMicroplastics are publicly recognized as a ubiquitous issue of environmental concern in aquatic systems. Primary consumers of microplastics are often zooplankton of biological and commercial importance, including the mysid shrimp, Americamysis bahia. In the presence of environmental stressors, gene expression may be altered without changing DNA sequences. This can occur through methylation of the DNA, in which a methyl group binds to nucleotide base pairs, most commonly cytosine. In this study, exposure to 5 micrometer microbeads at different concentrations caused no significant effect on mortality within 72 hours of exposure, but significantly increased mortality thereafter. Microplastics were shown to interact and accumulate on mysid bodies in various ways that would likely cause stress. An ELISA-like colorimetric assay was used to assess mysid shrimp genomic DNA for differences in global percent methylation that are potentially associated with microplastics exposure. No significant difference in the average percent of methylated DNA was found between treatment groups. There was no significant difference in the number methylation detections between treatments. This is the first study that has detected DNA methylation in any member of the order Mysida. This is the first study that has investigated DNA methylation effects as a result of microplastic induced stress.
Show less - Date Issued
- 2020, 2020
- Identifier
- 1206362804, WFE0000728
- Format
- Document (PDF)
- Title
- Investigating the epigenetic effects of microplastic exposure in Bluegills (Lepomis macrochirus) using methylation sensitive-AFLPs.
- Author
- Wilkinson, Sheridan Mae
- Abstract/Description
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Marine debris is an increasing threat to the world's oceans and the abundant organisms that inhabit them. Microplastics are remnants of macroplastics that have broken down to fragments smaller than 5mm through wave action and other natural processes or were originally manufactured to have micron-sized dimensions. These fragments are then consumed by microscopic marine organisms, like zooplankton, and are bioaccumulated up the trophic levels. Accumulation of plastics in the gut of organisms...
Show moreMarine debris is an increasing threat to the world's oceans and the abundant organisms that inhabit them. Microplastics are remnants of macroplastics that have broken down to fragments smaller than 5mm through wave action and other natural processes or were originally manufactured to have micron-sized dimensions. These fragments are then consumed by microscopic marine organisms, like zooplankton, and are bioaccumulated up the trophic levels. Accumulation of plastics in the gut of organisms can have a variety of repercussions, such as starvation due to blockage in the digestive tract, chemicals used in producing plastics leaching into the cells of organisms, and modifications to the genome. One such modification is methylation which is often associated with a decrease in gene activity. While methylation has been studied in teleost fishes, little work has been done to show how microplastic exposure affects this process in any species. For this study, we investigated the accumulation of methylation due to microplastic exposure within the genome of cultured Bluegill (Lepomis macrochirus) cells using methylation sensitive-AFLPs. Following MSAFLPs, the methylation state was analyzed through capillary gel analysis and electropherograms and found that differential methylation occurred between several of the control and experimental groups; however, these differences were not proven to be dose- or time-dependent.
Show less - Date Issued
- 2020, 2020
- Identifier
- 1222212928, WFE0000735
- Format
- Document (PDF)
- Title
- Microplastics in sandy environments in the Florida Keys and the Panhandle of Florida and ingestion by sea cucumbers and sand dollars.
- Author
- Plee, Tara Ashley
- Abstract/Description
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Microplastic pollution is an increasing problem in the marine environment. This study had five research objectives: establish if seagrass habitats are accumulating more microplastics compared to sandy habits in the Florida Keys; determine if there are microplastics present in sea cucumbers in the Florida Keys; determine the number of microplastics in Pensacola Beach sediment; determine the number of microplastics in St. Joseph Bay sediment; determine if there are microplastics present in sand...
Show moreMicroplastic pollution is an increasing problem in the marine environment. This study had five research objectives: establish if seagrass habitats are accumulating more microplastics compared to sandy habits in the Florida Keys; determine if there are microplastics present in sea cucumbers in the Florida Keys; determine the number of microplastics in Pensacola Beach sediment; determine the number of microplastics in St. Joseph Bay sediment; determine if there are microplastics present in sand dollars in the panhandle of Florida; and conduct a laboratory experiment on the sand dollar Mellita tenuis to determine if it is selecting for microplastics. Microplastics were extracted from samples using a saturated CaCl2 solution and visual examination. Both seagrass beds and sandy areas in the Florida Keys contained microplastics. Sediment near Pensacola Beach and in St. Joseph Bay contained microplastics. Sea cucumbers collected in the Florida Keys and sand dollars collected in the panhandle of Florida had microplastics as part of their gut content. In the laboratory, M. tenuis ingested microbeads in slightly lower proportions compared to surrounding sediment. Both sea cucumbers and sand dollars may make useful animals for monitoring sandy environments for microplastics pollution.
Show less - Identifier
- 1129598452, WFE0000667
- Format
- Document (PDF)
- Title
- Quantifying microplastics in fjords along the western Antarctic peninsula.
- Author
- Garza, Tristyn Nicole
- Abstract/Description
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Microplastic pollution is ubiquitous to water sources around the world, including freshwater, drinking water, salt water, and sea ice. Microplastics have also been documented in all parts of the water column from the sea floor and sediments to surface water. It was believed that microplastic pollution was concentrated in coastal areas with large human populations around the world. While remaining either entirely absent or minimal from remote areas where human influence is minimal such as in...
Show moreMicroplastic pollution is ubiquitous to water sources around the world, including freshwater, drinking water, salt water, and sea ice. Microplastics have also been documented in all parts of the water column from the sea floor and sediments to surface water. It was believed that microplastic pollution was concentrated in coastal areas with large human populations around the world. While remaining either entirely absent or minimal from remote areas where human influence is minimal such as in Antarctica, specifically the Antarctic Peninsula. This project determined microplastic concentration of three fjord habitats on the Western Antarctic Peninsula where glaciers are rapidly retreating within the fjords. Over a three-year period from 2017 to 2020 water samples were collected from the surface and benthos from 16 stations in Marian Cove, King George Island, Börgen Bay, Anvers Island, and Sheldon Glacier, Adelaide Island. For each station, three liters from the surface and three liters from the benthic were collected using a CTD rosette with Niskin Bottles, vacuum-filtered with a Buchner-Filter hand pump then, quantified under a compound microscope to determine the classification of microplastic, (fragment, fiber, or bead) color, and size. Comparisons over time and location were made in average microplastic per liter. It was determined that all the fjord habitats had microplastic present every year sampled, but the microplastic concentration was also increasing over time in the three fjords. This demonstrates that even with barriers such as the Antarctic Circumpolar Current, plastics are present and increasing in the Western Antarctic Peninsula during this time.
Show less - Identifier
- 1298600763, WFE0000785
- Format
- Document (PDF)