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Full-Text Articles in Physical Sciences and Mathematics
Benthic Algae Control Sediment-Water Column Fluxes Of Organic And Inorganic Nitrogen Compounds In A Temperate Lagoon, Ac Tyler, Kj Mcglathery, Iris C. Anderson
Benthic Algae Control Sediment-Water Column Fluxes Of Organic And Inorganic Nitrogen Compounds In A Temperate Lagoon, Ac Tyler, Kj Mcglathery, Iris C. Anderson
VIMS Articles
Coastal lagoons are a common land-margin feature worldwide and function as an important filter for nutrients entering from the watershed. The shallow nature of lagoons leads to dominance by benthic autotrophs, which can regulate benthic-pelagic coupling. Here we demonstrate that both microalgae and macroalgae are important in controlling dissolved inorganic as well as organic nitrogen (DIN and DON) fluxes between the sediments and the water column. Fluxes of nitrogen (NH4+, NO3-, DON, urea, and dissolved free and combined amino acids [DFAA, DCAA]) and O-2 were measured from October 1998 through August 1999 in sediment cores collected from Hog Island Bay, …
Penetration Of Anthropogenic Carbon Into Organic Particles Of The Deep Ocean, Erm Druffel, Je Bauer, S Griffin, J Hwang
Penetration Of Anthropogenic Carbon Into Organic Particles Of The Deep Ocean, Erm Druffel, Je Bauer, S Griffin, J Hwang
VIMS Articles
] In the late 1980s, bomb C-14 was present in suspended particulate organic carbon (POC) from the North Central Pacific (NCP) and Sargasso Sea ( SS) throughout most of the water column, demonstrating that deep POC had exchanged with atmospheric CO2 in the past 30 years. Upon reoccupation of these sites in 1999 and 2000, respectively, we observed that the delta(13)C values of suspended POC were lower than those measured a decade earlier. This demonstrates that anthropogenic CO2 from fossil fuel and biomass burning has penetrated a major organic matter pool in the deep ocean. Delta(14)C measured in the suspended …
Microbial Dynamics And Biogeochemistry In The North Pacific Subtropical Gyre, Matthew J. Church
Microbial Dynamics And Biogeochemistry In The North Pacific Subtropical Gyre, Matthew J. Church
Dissertations, Theses, and Masters Projects
The research presented in this dissertation describes the influence of planktonic bacterial growth on upper ocean organic matter dynamics in the North Pacific Subtropical Gyre (NPSG). Examination of the temporal dynamics in dissolved organic matter (DOM) was coupled with investigations that targeted the influence of heterotrophic bacterial production (HBP) on organic matter fluxes in the NPSG. Nine cruises to the Hawaii Ocean Time-series field site Station ALOHA revealed that HBP accounted for a large flux of organic carbon in the upper ocean of the NPSG. HBP was significantly enhanced by sunlight, with photoenhancement of HBP accounting for 3.2 mol C …
Availability Of Humic Nitrogen To Phytoplankton, Jason Holt See
Availability Of Humic Nitrogen To Phytoplankton, Jason Holt See
Dissertations, Theses, and Masters Projects
The chemical, physical, and biological factors affecting the bioavailability of humic nitrogen (N) to coastal phytoplankton were examined. Historically, humic substances have largely been considered biologically refractory, and humic-N is though to be unavailable biologically without prior oxidation via photochemical cleavage or remineralization by bacteria. This is due in part to the high aromaticity and low N content of humic substances. This dissertation investigates whether these assumptions are valid, and whether humic substances may be a more important source of N to the coastal phytoplankton community than previously believed. The research consisted of four main parts. First, changes in the …
Transport Of Dissolved Inorganic Carbon From A Tidal Freshwater Marsh To The York River Estuary, Sc Neubauer, Iris C. Anderson
Transport Of Dissolved Inorganic Carbon From A Tidal Freshwater Marsh To The York River Estuary, Sc Neubauer, Iris C. Anderson
VIMS Articles
The cycling of dissolved inorganic carbon (DIC) and the role of tidal marshes in estuarine DIC dynamics were studied in a Virginia tidal freshwater marsh and adjacent estuary. DIC was measured over diurnal cycles in different seasons in a marsh tidal creek and at the junction of the creek with the adjacent Pamunkey River. In the creek, DIC concentrations around high tide were controlled by the same processes affecting whole-estuary DIC gradients. Near low tide, DIC concentrations were 1.5-5-fold enriched relative to high tide concentrations, indicating an input of DIC from the marsh. Similar patterns (although dampened in magnitude) were …