Seafloor Iron Mobilization Across The Deep-Water Redox Gradients Of The Black Sea And The Sea Of Marmara

Alımlı, Nimet
Iron is one of the key elements in the ocean which has wide interconnections with other essential elements (i.e., C, N, P, O, Mn, S) and fundamental mechanisms (i.e., photosynthesis, respiration, chemosynthesis). The critical role of iron, since the beginning of life until the modern oceans, was increasing with biogeochemical evolution creating new niches for iron. Despite iron is ubiquitous on land, its trace level presence in the ocean creates difficulties for iron studies. Hence, the complex cycle of iron still has many gaps and filling the gaps is crucial to understand the past, present and the future of oceans and moreover Earth. In this thesis work, benthic dissolved iron patterns in the Black Sea and for the first time in the Sea of Marmara was studied in the comparison of recent redox changes and well-established redox environments. High amounts of dissolved iron were measured, and high benthic fluxes estimated for the Sea of Marmara showing that, in terms of iron source, it is comparable to other oxygen minimum zones. The potential connection between the organic complexation and porewater size fractions is examined with comparison of more established iron fraction species. The results from seawater and porewater size fractionations indicated that the nature of the seawater and porewater species are different at least to the extent of different influences by sample handling. In summary, the iron patterns in the Sea of Marmara indicates the recent hypoxia have already cause iron to be mobilized at the seafloor and the sedimentary colloidal andvi soluble phases needs a more detailed attention to understand the effective scale of benthic iron species.


Ecogeochemical fate of coarse organic particles in sediments of the Rhone River prodelta
CHARLES, Francois; COSTON-GUARİNİ, Jennifer; LANTOİNE, Francois; Guarini, Jean-Marc; Yücel, Mustafa (2014-03-20)
Coarse particulate organic matter (CPOM) represents a small portion of the inner shelf sediments but occurs across all river outlets. To consider the ecogeochemical fate of CPOM in such an environment, we examined both the infauna community and secondary evidence of geochemical reactions preserved in the surface sediments of the Rhone prodelta. ICP-AES, scanning electron microscopy and energy dispersive X-ray spectrometry of the CPOM showed that the fate of organic matter in this environment is driven by su...
Earthquake-induced turbidite deposition as a previously unrecognized sink for hydrogen sulfide in the Black Sea sediments
Yücel, Mustafa; Moore, Willard S. (2010-08-20)
The depth profiles of excess Pb-210, Cs-137, elemental sulfur, reactive iron and porewater hydrogen sulfide of a western central basin sediment core in the Black Sea collectively point to the presence of a 20 cm thick reactive iron rich turbidite layer. This layer was most probably deposited there after the 1999 earthquakes in Northwestern Turkey, which caused oxidation of porewater hydrogen sulfide and anomalous accumulation of the product elemental sulfur in the solid phase.
Zooplankton of the Black Sea and the Eastern Mediterranean Similarities and dissimilarities
Kovalev, Av; Mazzocchı, Mg; Sıokoufrangou, I.; Kıdeyş, Ahmet Erkan (2001-01-01)
A synthesis of data on abundance and biomass of zooplankton in the Eastern Mediterranean (EMED) and the Black Sea shows major differences in the composition and structure of pelagic communities in the two basins. Few Mediterranean planktonic animals have invaded in the Black Sea. The great bulk of Black Sea species is represented by coastal inhabitants that spread throughout the whole basin. This process has been called “neritization” of the Black Sea fauna. Peculiarities in zooplankton assemblages of the B...
Iron metabolism and drug resistance in cancer
Kazan, Hasan Huseyin; Urfali-Mamatoglu, Cagri; Gündüz, Ufuk (2017-10-01)
Iron is an essential inorganic element for various cellular events. It is directly associated with cell proliferation and growth; therefore, it is expected that iron metabolism is altered in tumor cells which usually have rapid growth rates. The studies on iron metabolism of tumor cells have shown that tumor cells necessitated higher concentrations of iron and the genes of iron uptake proteins were highly over-expressed. However, there are limited number of studies on overall iron metabolism in drug-resista...
Marine Chemical Technology and Sensors for Marine Waters: Potentials and Limits
Moore, Tommy S.; Mullaugh, Katherine. M.; Holyoke, Rebecca R.; Madison, Andrew S.; Yücel, Mustafa; Luther, George W. (2009-01-01)
A significant need exists for in situ sensors that can measure chemical species involved in the major processes of primary production (photosynthesis and chemosynthesis) and respiration. Some key chemical species are O-2, nutrients (N and P), micronutrients (metals), pCO(2), dissolved inorganic carbon (DIC) pH, and sulfide. Sensors need to have excellent detection limits, precision, selectivity, response time, a large dynamic concentration range, low power consumption, robustness, and less variation of inst...
Citation Formats
N. Alımlı, “Seafloor Iron Mobilization Across The Deep-Water Redox Gradients Of The Black Sea And The Sea Of Marmara,” M.S. - Master of Science, Middle East Technical University, 2022.