Seasonal variations in dissolved organic matter composition using absorbance and fluorescence spectroscopy in the Dardanelles Straits – North Aegean Sea mixing zone

The effect of Black Sea Water (BSW) inputs on the North Aegean Sea productivity and food web dynamics was investigated, by means of sensitivity simulations, investigating the effect of the inflowing BSW, in terms of inorganic nutrients and dissolved organic matter. The model used has been successfully applied in the area in the past and extensively presented. Considering the importance of the microbial loop in the ecosystem functioning, the role of the dissolved organics and in order to achieve a more realistic representation of the Dissolved Organic Matter pool, the bacteria sub-model was appropriately revised. The importance of the microbial loop is highlighted by the carbon fluxes where almost 50% of carbon is channelled within it. The impact of dissolved organic matter (DOM) (in the inflowing to the Aegean Sea, BSW) appears to be stronger than the impact of dissolved inorganic nutrients, showing a more extended effect over the N Aegean. Bacterial production and biomass is more strongly affected in the simulations by modified DOM, unlike phytoplankton biomass and production, which are more dependent on the inflowing nutrients and particularly phosphorus (inorganic and dissolved organic). In the phytoplankton composition, the dinoflagellates appear to be mostly affected, being favoured by higher nutrient availability at the expense of all other groups, particularly picoplankton, indicating a shift to a more classical food chain.

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High oxygen consumption rates in the deep layers of the North Aegean Sea (eastern Mediterranean)

Mediterranean Marine Science ◽

10.12681/mms.258 ◽

2002 ◽

Vol 3 (1) ◽

pp. 55 ◽

Cited By ~ 7

Author(s):

E. SOUVERMEZOGLOU ◽

E. KRASAKOPOULOU

Keyword(s):

Organic Matter ◽

Oxygen Consumption ◽

Aegean Sea ◽

High Oxygen ◽

Dense Water ◽

The North ◽

Water Formation ◽

Deep Layers ◽

North Aegean ◽

North Aegean Sea

Severe winter meteorological conditions promote dense water formation over the shelves of the North Aegean Sea. The newly formed dense water fills the deep basins of the North Aegean Sea, contributing to their ventilation and the downward transport of organic and inorganic material. The great bathymetric variability imposes limitations on the deep circulation and the communication between the various basins and makes the North Aegean Sea an appropriate area for the monitoring of oxygen consumption in the deep layers. Historical hydrographic data suggest that there was extensive production of dense water in the North Aegean Sea on two occasions during the last decade, the winters of 1987 and 1992-1993. Our data series from August 1986 to September 1989 and from March 1997 to February 1999, permitted us to follow, step by step, the oxygen consumption and the nutrient regeneration in the deep basins of the northern Aegean Sea during these periods of isolation. The organic matter reaching the bottom layer just after the deep water formation event is rich in labile and easily oxidizable material and its decomposition leads to a significant oxygen uptake during the first year of stagnation. The further decomposition of the remaining semi-labile and refractory material turns over on greater time scales, by consuming lesser amounts of oxygen. A more significant oxygen decrease is recorded in the eastern basin (Lemnos Basin) of the North Aegean Trough, than in the central (Athos Basin) and the western (North Sporades Basin) ones and is attributed to the irregular contribution of the Black Sea Water (BSW) to the water masses formed on the different shelves of the North Aegean Sea. Our results and the existing data on the Turkish straits showed that dissolved organic matter is the major constituent responsible for this high oxygen consumption. The slightly different particulate organic carbon fluxes to these depressions play a secondary role.

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Application of Orbitrap mass spectrometry to investigate seasonal variations of dissolved organic matter composition in a eutrophic lake in Japan

Environmental Science Water Research & Technology ◽

10.1039/d0ew00129e ◽

2020 ◽

Vol 6 (7) ◽

pp. 1816-1827

Author(s):

Vitharuch Yuthawong ◽

Ikuro Kasuga ◽

Futoshi Kurisu ◽

Hiroaki Furumai

Keyword(s):

Mass Spectrometry ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Seasonal Variations ◽

Eutrophic Lake ◽

Organic Matter Composition ◽

Orbitrap Mass Spectrometry

Orbitrap mass spectrometry can reveal the composition of DOM and the fraction responsible for CODMn in an eutrophic lake.

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Faculty Opinions recommendation of Fluorescence spectroscopy reveals ubiquitous presence of oxidized and reduced quinones in dissolved organic matter.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1029841.347545 ◽

2005 ◽

Author(s):

Dianne Newman

Keyword(s):

Organic Matter ◽

Fluorescence Spectroscopy ◽

Dissolved Organic Matter ◽

Ubiquitous Presence

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Geodetic analysis of the tectonic crustal deformation pattern in the North Aegean Sea, Greece

Mediterranean Geoscience Reviews ◽

10.1007/s42990-021-00049-6 ◽

2021 ◽

Author(s):

Ilias Lazos ◽

Sotirios Sboras ◽

Christos Pikridas ◽

Spyros Pavlides ◽

Alexandros Chatzipetros

Keyword(s):

Crustal Deformation ◽

Aegean Sea ◽

Deformation Pattern ◽

The North ◽

North Aegean ◽

North Aegean Sea

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Impact of aquaculture on distribution of dissolved organic matter in coastal Jeju Island, Korea, based on absorption and fluorescence spectroscopy

Environmental Science and Pollution Research ◽

10.1007/s11356-021-15553-3 ◽

2021 ◽

Author(s):

Jeonghyun Kim ◽

Yeseul Kim ◽

Sung Eun Park ◽

Tae-Hoon Kim ◽

Bong-Guk Kim ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Fluorescence Spectroscopy ◽

Dissolved Organic Matter ◽

Coastal Water ◽

Coastal Region ◽

Principal Component ◽

Distribution Patterns ◽

Organic Pollution ◽

Jeju Island

AbstractIn Jeju Island, multiple land-based aquafarms were fully operational along most coastal region. However, the effect of effluent on distribution and behaviours of dissolved organic matter (DOM) in the coastal water are still unknown. To decipher characteristics of organic pollution, we compared physicochemical parameters with spectral optical properties near the coastal aquafarms in Jeju Island. Absorption spectra were measured to calculate the absorption coefficient, spectral slope coefficient, and specific UV absorbance. Fluorescent DOM was analysed using fluorescence spectroscopy coupled with parallel factor analysis. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured using high-temperature catalytic oxidation. The DOC concentration near the discharge outlet was twice higher than that in natural groundwater, and the TDN concentration exponentially increased close to the outlet. These distribution patterns indicate that aquafarms are a significant source of DOM. Herein, principal component analysis was applied to categorise the DOM origins. There were two distinct groups, namely, aquaculture activity for TDN with humic-like and high molecular weights DOM (PC1: 48.1%) and natural biological activity in the coastal water for DOC enrichment and protein-like DOM (PC2: 18.8%). We conclude that the aquafarms significantly discharge organic nitrogen pollutants and provoke in situ production of organic carbon. Furthermore, these findings indicate the potential of optical techniques for the efficient monitoring of anthropogenic organic pollutants from aquafarms worldwide.

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