Ecogeochemical fate of coarse organic particles in sediments of the Rhone River prodelta

2014-03-20
CHARLES, Francois
COSTON-GUARİNİ, Jennifer
LANTOİNE, Francois
Guarini, Jean-Marc
Yücel, Mustafa
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 sulphate reduction and geochemical reactions resulting from the precipitation of sulfide due to the presence of large amounts of iron-bearing minerals. Leaf litter debris contained such high quantities of iron that after dry ashing the remaining material is easily attracted by a magnet. The observed geochemical trade-off was proposed as a mechanism that helps to maintain a bioturbating animal community that in turn contributes to the mineralization of organic matter within this suboxic environment. This study showed that the accumulation of refractory organic carbon in sediments was intimately associated with the sequestering of iron and sulphur by providing a nucleation point for mineral deposition and also that the extent of decomposition of the organic materials did not necessarily increase progressively from coarser to finer particles.
ESTUARINE COASTAL AND SHELF SCIENCE

Suggestions

Spatial and Temporal Variations of Inorganic and Organic Forms of Phosphorus in the Surface and Deep Waters of Erdemli Shelf Zone of Mersin Bay
DOĞAN SAĞLAMTİMUR, NESLİHAN; Tuğrul, Süleyman (2013-01-01)
The aim of this study was to understand spatial and temporal variations of inorganic and organic forms of phosphorus in the surface and deep waters of Erdemli shelf zone of the Mersin Bay. For this goal, timeseries hydrographical and phosphorus data were obtained monthly at the three selected stations between December 2001 and December 2003. The present results have shown that the concentrations of different fractions of total phosphorus displayed a decreasing trend from nearshore to shelfbreak zone of the ...
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...
Effects of river inputs on particulate organic matter composition and distributions in surface waters and sediments of the Mersin Bay, Northeastern Mediterranean Sea
Akçay, İsmail; Tuğrul, Süleyman; Özhan, Koray (2022-05-01)
Terrestrial inputs-induced eutrophication in the P-depleted Northeastern (NE) Mediterranean shelf waters has led to changes in particulate organic matter (POM) composition and distributions in the water column and surface sediments. The present study aimed to understand the impacts of terrestrial nutrient and POM inputs on coastal eutrophication, bulk POM composition and concentrations in surface waters and sediments of the Mersin Bay, located at the Cilician Basin of NE Mediterranean Sea. The present resul...
Epicontinental seas as efficient carbon sinks: proto-Paratethys & West Siberian seas during the PETM
Kaya, Mustafa Yücel; Dupont‐Nivet, G; Frieling, Joost; Fioroni, C; Rohrmann, A; Altıner, Sevinç; Vardar, Ezgi; Plesse, Birgit; Mamtimin, Mehmut; Zhaojie, Guo (2020-05-04)
Removal of carbon on geological timescales is generally assumed to be governed by the relative strength of silicate weathering and organic carbon burial. For past transient warming phases organic carbon burial has been considered as a relevant negative feedback, but it remains uncertain how this compares to present-day anthropogenic emissions. The ocean is very effective at organic carbon remineralization and, only certain regions bury significant amounts of organic carbon. Organic carbon burial hotspots in...
Geographic patterns of elemental deposition in the Aegean region of Turkey indicated by the lichen, Xanthoria parietina (L.) Th. Fr.
Yenisoy-Karakas, S; Tuncel, Süleyman Gürdal (2004-08-15)
Lichen samples from different parts of the world have been known to accumulate elements to a greater degree than higher plants, if they are exposed to these elements from the atmosphere or from water and sediments. It has been hypothesized that lichens can be used to monitor air pollution around point and area emission sources. Local variation (variation in substrate, age and morphology of lichen samples) of element concentrations would not be large enough to affect the concentration patterns in large areas...
Citation Formats
F. CHARLES, J. COSTON-GUARİNİ, F. LANTOİNE, J.-M. Guarini, and M. Yücel, “Ecogeochemical fate of coarse organic particles in sediments of the Rhone River prodelta,” ESTUARINE COASTAL AND SHELF SCIENCE, pp. 97–103, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31410.