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Full-Text Articles in Physical Sciences and Mathematics

Iron Geochemistry Across An Estuary-To-Coastal Gradient, Lissett G. Diaz Dec 2021

Iron Geochemistry Across An Estuary-To-Coastal Gradient, Lissett G. Diaz

Honors Theses

Iron is a ubiquitous earth element that participates in biogeochemical processes that occur in marine sediments. Microorganisms utilize iron for many purposes, including cell growth, conserving energy, and for maintaining metabolic activity. In coastal sedimentary settings, understanding the redox reactions involving ferric iron, Fe3+, and ferrous iron, Fe2+, in its solid phase and pore-water phases, respectively, enable an appreciation of biogeochemical transformations occurring in the coastal zone. In this study, iron concentrations in sediment of ranging permeability were determined at four stations marking an estuary-coast transition zone in Singleton Swash in Myrtle Beach, South Carolina. The …


Plastic Debris In The Laurentian Great Lakes System, North America: Analysis Of Types, Abundances, And Sources, Ian A. Arturo Feb 2021

Plastic Debris In The Laurentian Great Lakes System, North America: Analysis Of Types, Abundances, And Sources, Ian A. Arturo

Electronic Thesis and Dissertation Repository

Understanding plastic pollution in the Laurentian Great Lakes system requires investigation of all plastic debris sizes and categories. Visible polymeric debris (VPD) mainly characterize shorelines, and microplastics (MPs;mm) are found in benthic and beach sediment. Field sampling of VPD from all five Great Lakes, visual and chemical identification of VPD types, and implementation of a matrix scoring technique (MST) indicate that plastic industries, urban areas, and shoreline recreation are major sources of VPD. Sampling for MPs in the St. Clair system, followed by preliminary density separation, and microscopy, suggest that wastewater treatment plants are a major source. This work is …


Dissolved Inorganic Nitrogen Dynamics In Swash Zone Sands Of Long Bay, Sc, Alexis F. Echols Apr 2019

Dissolved Inorganic Nitrogen Dynamics In Swash Zone Sands Of Long Bay, Sc, Alexis F. Echols

Honors Theses

A key component affecting the biogeochemistry of the sedimentary environment is pore water between grains of sediments. Sedimentary microorganisms are constantly modifying chemical compounds as part of their life functions which are then exchanged between the sediment column and the overlying water column. Dissolved inorganic nitrogen, a major element for life, takes on several forms including nitrate, nitrite, and ammonium which vary in concentration throughout the sediment and with respect to each other. The relative concentrations of these nitrogen species have been previously briefly explored in sandy columns, where redox gradients that control their relative concentrations can be fairly deep …


Legacy Sediment Controls On Post-Glacial Beaches Of Massachusetts, Alycia Ditroia Mar 2019

Legacy Sediment Controls On Post-Glacial Beaches Of Massachusetts, Alycia Ditroia

Masters Theses

Here we examine seasonal grain-size trends on 18 beaches in the Northeastern US and dispersed along the post-glacial coast of Massachusetts (USA) in order to explore the mechanisms influencing median grain size and slope. Over 800 grain size samples were collected along 200 summer and winter cross-shore beach elevation surveys. Obtained grain size and beach slope data are compared to coastal morphology, sediment source, wave height, and tidal magnitude in order to ascertain controls on beach characteristics. In general, median grain size increases with intertidal beach slope in the study region. However, grain sizes along post-glaciated beaches in the study …


Characterizing Diatom Biofilms And Their Influence On The Sand Biogeochemistry Of High Energy Beaches, Logan C. Jarrell Oct 2018

Characterizing Diatom Biofilms And Their Influence On The Sand Biogeochemistry Of High Energy Beaches, Logan C. Jarrell

Honors Theses

High energy beaches are among the most dynamic ecological settings on Earth. Compared to mudflats, diatoms of high energy beaches have been more neglected in the literature, particularly true of the intertidal biofilms that form and dissipate with nutrient cycling and light intensity over the tidal cycle. Although short lived, the productivity of these biofilms may be critical to the organic-poor sand. Through sediment coring and subsequent analyses of the uppermost sand of three suspected biofilm stations—non-runnel, runnel crest, and runnel trough—along with seemingly bare sand as a control, this study sought to verify the presence of diatom biofilms and …


Anthropogenic Influences And Meteorological Effects: How They Are Changing The Sand Beaches In Southern Maine, Heather W. Heinze Dec 2001

Anthropogenic Influences And Meteorological Effects: How They Are Changing The Sand Beaches In Southern Maine, Heather W. Heinze

Electronic Theses and Dissertations

Although sand beaches in southern Maine comprise only a small segment of the coastline, they are economically important to the state. From September 1999-March 2001, volunteers made monthly topographic profiles along nine beaches in southern Maine to monitor changes. The volunteers used the Emery Method of beach profiling to take simultaneous measurements at spring low tide. The beaches are significantly different with respect to physiography, incident wave energy and direction, available sediment supply and extent of development. An average of the profiles for each category demonstrates that the undeveloped beaches experienced regular seasonal fluctuations and a consistent berm elevation from …


Green Sea Turtle (Chelonia Mydas) Hatchlings Success: The Effects Of Artificial Lights And Other Human Impacts, Hui-Yu Tracy Liang Apr 2000

Green Sea Turtle (Chelonia Mydas) Hatchlings Success: The Effects Of Artificial Lights And Other Human Impacts, Hui-Yu Tracy Liang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sea turtles appeared more than 200 million years ago in the late Triassic period. They grow very slowly, taking an average of 25 years to reach sexual maturity, with a life span averaging 40-50 years. From May to October green sea turtles (Chelonia mydas) emerge during the night and follow light cues toward the sea. Recently, beachfront development has increased hatchling mortality rate. When hatchlings emerge from nest, high densities of artificial lights lead them toward the land where they either desiccate and die, or are preyed upon. Short-wavelength high intensity light and the distance of artificial light are the …