Distinct patterns of sedimentary phosphorus fractionation and mobilization in the seafloor of the Black Sea, Marmara Sea and Mediterranean Sea

2023-03-10
Phosphorus (P) is a key element to all life that is used for structural and functional component of all organisms. The cycling of sedimentary P may differ depending on the redox-conditions of the overlying waters affecting the dynamics, and distribution of P-fractions and the elements that are highly coupled to P cycle. Though biogeochemistry of water column in the three interconnected marine basins of Black, Marmara and Mediterranean Seas have been studied extensively, few studies were carried out to understand sedimentary P dynamics in these regions. In this study, therefore, the biogeochemical cycling of sedimentary P and related variables such as porewater nutrients, sedimentary organic carbon, nitrogen and reactive iron were studied in selected sites at the three interconnected marine basins: Black Sea, Marmara and Northeastern (NE) Mediterranean Sea. The pool of “potentially mobile P” was also determined for the studied sites. The study results showed that porewater and sediment biogeochemistry displayed great variability in the studied sites with the maximum concentrations of porewater phosphate, ammonium, reactive silicate, surface sediment organic carbon, nitrogen, phosphorus and total phosphorus (TP) measured in the hypoxic Marmara Sea and suboxic/anoxic Black Sea. The decline in the TP concentrations of all sediment core samples indicated P-mobilization to the overlying water. The pool of “potentially mobile P” varied between 0.023 and 0.148 mol/m2 in the studied sites with the maximum values recorded in suboxic and anoxic/sulfidic parts of the Black Sea. This study predicts that the deoxygenation and eutrophication would further lead to the preferential release of P in these three interconnected marine basins, hence changing the remineralization, N/P molar ratios and eventually transform the deep-water nutrient stocks with implications for internal N/P control on marine ecosystems.
Science of the Total Environment

Suggestions

Seafloor Iron Mobilization Across The Deep-Water Redox Gradients Of The Black Sea And The Sea Of Marmara
Alımlı, Nimet; Yücel, Mustafa; Department of Chemical Oceanography (2022-8)
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 iro...
The use of nuclear techniques in source apportionment studies, exemplified by recent studies in Turkey
GÜLLÜ, GÜLEN; Tuncel, Süleyman Gürdal (2004-01-01)
Nuclear analytical methods are very important atmospheric tools as they provide multielement data, which is essential for receptor modeling. In this study, the application of receptor modeling is discussed on rural data to determine source regions affecting chemical composition of aerosols in the Eastern Mediterranean. The factor analysis revealed 4 sources, two of which represent anthropogenic component in aerosol mass. The source regions that determine the composition of particles is investigated using tr...
Changes in gene profile of human hepatocellular carcinoma cell line (HepG2) induced by boric acid at half mazimal inhibitory concentration (IC50).
Tombuloğlu, Ayşegül; Çöpoğlu, Hülya; Güray, Nülüfer Tülün; Aydın Son, Yeşim (null; 2017-06-30)
Boron is an essential micronutrient for many biological processes in plants and animals. In humans, adverse health outcomes are reported for both boron deprivation and excessive boron intake. Humans might get exposed to high doses of boron by consuming boron containing products or by working at boron enriched workplaces. In this study, the aim is to find out about the cytotoxicity mechanisms of boric acid, the most abundant form of boron containing compounds in human blood, on human hepatocellular carcinoma...
Parametric studies on cell flotation of Mazidağı phosphate rock
Öztin, Z. Elif; Özbelge, Önder; Karakaş, Gürkan; Department of Chemical Engineering (2003)
Phosphate is one of the essential minerals for all living organisms. It has to be supplied to the soil in order for plant growth. In Turkey, most of the soils lack phosphate mineral. Although this can be overcome by the use of phosphate fertilizers, in Turkey there are no phosphate mines being utilized; and this brings about the need to import phosphate rock and phosphate fertilizers. The estimated phosphate rock reserve of Turkey is around 300 million tons, but it cannot be utilized since no economical met...
Studies on chiral spiropyran derivatives
Şentürk, Bengi; Akdağ, Akın; Department of Chemistry (2021-8-13)
Spiropyrans are a class of organic molecules that possess photochromic characteristics. Their isomerization to the merocyanine form can be induced by light, heat, polarity, and pH of the environment. The merocyanine form is obtained from the heterolytic cleavage of the bond between spiro carbon and the oxygen, which results in a transformation of the optically active spiropyrans into an achiral form. The back conversion of the achiral merocyanine to the spiropyrans leads to racemization. In this study, D an...
Citation Formats
İ. Akçay and M. Yücel, “Distinct patterns of sedimentary phosphorus fractionation and mobilization in the seafloor of the Black Sea, Marmara Sea and Mediterranean Sea,” Science of the Total Environment, vol. 863, pp. 0–0, 2023, Accessed: 00, 2023. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85144294755&origin=inward.