Digital Commons Network^™

Sensitivity Of Aquatic Organic Matter Degradation To Changing Temperature And Nutrient Conditions In A Coastal Watershed, Curtis John Szewczyk

Theses and Dissertations

The degradation of organic matter (OM) within inland waters plays a pivotal role in the global carbon cycle and quantifying carbon budgets. Here, measurements of dissolved oxygen (DO) decay rates were used to infer the extent and kinetics of OM degradation under variable conditions. The goal of the investigation was to quantify how OM samples within the Waccamaw River watershed, South Carolina, respond to changes in temperature and nutrient availability as a function of their source location and lability. Samples were collected from urbanized stormwater detention ponds and undeveloped upland forested wetland drainages to provide contrasting and distinct OM sources …

Spatial And Temporal Variability In Carbon And Nutrient Concentrations Within The North Inlet Estuary,Sc, Heather Kish

Theses and Dissertations

Coastal wetlands provide numerous ecosystem services, including the ability to sequester and store significant amounts of organic carbon (so-called “blue carbon”). Variability in carbon storage within marshes represents a major information gap in understanding and quantifying the role saltmarshes play in the global carbon cycle. This study quantified decadal and small-scale variability in carbon and nutrient concentrations across tidal inundation gradients in the relatively pristine North Inlet Estuary, South Carolina. Sampling took place within two segments of the marsh platform of Crab Haul Creek, the landward-most basin within North Inlet. In the summer of 2020, a total of 200 sediment …

Characterizations Of Dissolved Organic Carbon At Hydrothermal Systems Of The Midcayman Rise, Aaron Mau

Theses and Dissertations

Marine dissolved organic carbon (DOC) is a carbon reservoir comparable in size to all atmospheric CO2 and is composed primarily of refractory material which can be thousands of years old. Circulation through hydrothermal systems has been demonstrated to profoundly alter this material, but the mechanisms that lead to addition, removal, and alteration of DOC are poorly understood. Consequently, the contribution of hydrothermal systems to organic carbon cycling in the deep ocean – and the biological and geochemical processes exhibited at different venting environments – remain highly uncertain.

In January 2020, samples were collected from two hydrothermal vent fields at the …

Caribbean Yellowtail Snapper Ocyurus Chrysurus: Filling In Critical Gaps In Research For Life History And Novel Ageing Validation Utilizing Δ14C, Sarah Zajovits

Theses and Dissertations

Yellowtail snapper Ocyurus chrysurus is an important fisheries species in the US Caribbean; in waters of Puerto Rico, it ranks second for reef fishes in terms of annual total commercial landings. However, a paucity of information exists concerning basic life history information for Caribbean yellowtail snapper populations. This study provides the first comprehensive documentation of age, growth, and reproductive biology of yellowtail snapper from the Caribbean and is the first to directly validate age estimation in this species. Sampling of 1731 yellowtail snapper occurred in Puerto Rico and the U.S. Virgin Islands during 2013-2021 from fisheries-dependent and –independent efforts. Fish …

Dissolved Nitrogen Cycling In The Eastern Canadian Arctic Archipelago From Stable Isotopic Data, Holly Westbrook

Theses and Dissertations

Climate change is expected to drastically alter the input of inorganic nitrogen (N) sources in the Eastern Canadian Arctic Archipelago (ECAA) with increasing discharge from glacial meltwater and permafrost thawing. Since dissolved inorganic N is generally depleted in surface waters, dissolved organic N (DON) could represent a significant source of nutrients limiting primary production in Arctic ecosystems. Yet, few DON data for this region exist. We analyzed stable isotopes (δ¹⁵N and δ ¹⁸O of DON and NO₃-) to investigate dissolved nitrogen cycling in glacial rivers and marine surface samples collected in the ECAA during summer …

Zooplankton Community Structure And Grazing Within A Stormwater Detention Pond In Coastal South Carolina, Kristen Laccetti

Theses and Dissertations

Stormwater detention ponds (SDPs) on the coast of South Carolina have become increasingly prevalent as the area experiences rapid urbanization. SDPs are man-made reservoirs implemented to minimize pollution inputs into receiving waters and are home to diverse biota, including zooplankton. Zooplankton are a good water quality indicator due to their quick response times and trophic regulators of phytoplankton through grazing. Zooplankton and phytoplankton interactions in stormwater detention ponds are an essential component for understanding plankton community dynamics in SDPs. This purpose of this study was to determine the seasonal variability in zooplankton community composition and grazing rates at 14-day intervals …

Fortnightly Effects Of Urea Additions On Cyanobacteria In A Stormwater Detention Pond, Halley Carruthers

Theses and Dissertations

Increased urban and suburban population growth along the South Carolina (SC) coast has led to a rise in impervious surfaces, altering the course of stormwater runoff events. The construction of stormwater detention ponds (SDPs) is one of the many ways to best mitigate the flow of this water. In their function as natural pollutant traps, SDPs often contain increased levels of nutrients (nitrogen, N and phosphorus, P), which can lead to eutrophication. Under these high eutrophic conditions, primary production is overstimulated, and the formation of phytoplankton blooms, including harmful algal blooms (HABs) can occur. In recent decades, the forms of …