scholarly journals MONITOX international network for monitoring of environmental toxicants and risk assessment in the Black Sea basin: research and interdisciplinary cooperation dimensions

2021 ◽  
Author(s):  
Antoaneta Ene ◽  
◽  
Elena Zubcov ◽  
Thomas Spanos ◽  
Oleg Bogdevich ◽  
...  
Keyword(s):  
Black Sea ◽  
Temporal Distribution ◽  
Interdisciplinary Studies ◽  
Danube River ◽  
The Black Sea ◽  
Toxic Substances ◽  
Environmental Toxicants ◽  
Danube Delta ◽  
Republic Of Moldova ◽  
Sea Coast

The paper presents the main tackled issues and results concerning the monitoring of the toxic substances (TOXs) in the network established in the frame of BSB27 MONITOX project, implemented by «Dunarea de Jos» University of Galati, Romania (Leader Partner) in partnership with Institute of Zoology, Republic of Moldova, International Hellenic University (IHU), Greece, Institute of Geology and Seismology, Republic of Moldova (IGS), and “Danube Delta” National Institute for Research and Development, Tulcea, Romania. Maps of pollution of water, sediments, soils and biota with TOXs built using ArcGIS and Q-GIS highlight their levels and spatial-temporal distribution in the target zones in the three countries: Danube River (Lower sector), Prut and Dniester Rivers, Danube Delta, Black Sea coast, Nestos River and delta and Northern Aegean Sea coast. The strategy designed and results of the interdisciplinary studies performed in the period 2018-2021 on a large range of toxic pollutants in the Black Sea Basin (including NE part of Greece) are emphasized, as well as the assessment of toxicants’ impact upon human health using a health risk calculator developed as ICT tool.

scholarly journals Sedimentary microplastic concentrations from the Romanian Danube River to the Black Sea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Iulian Pojar ◽  
Adrian Stănică ◽  
Friederike Stock ◽  
Christian Kochleus ◽  
Michael Schultz ◽  
...  
Keyword(s):  
Black Sea ◽  
Danube River ◽  
The Black Sea ◽  
Danube Delta ◽  
Black Sea Coast ◽  
River Danube ◽  
Terrestrial Environments ◽  
Ultimate Fate ◽  
First Time ◽  
Sea Coast

AbstractA multitude of recent studies have detailed microplastic concentrations in aquatic and terrestrial environments, although questions remain over their ultimate fate. At present, few studies have detailed microplastic characteristics and abundance along a freshwater–marine interface, and considerable uncertainties remain over the modelled contribution of terrestrial and riverine microplastic to the world’s oceans. In this article, for the first time, we detail sedimentary microplastic concentrations along a River–Sea transect from the lower reaches of a major continental river, the River Danube, through the Danube Delta, the Black Sea coast to the Romanian and Bulgarian inner shelf of the Black Sea. Our results indicate that isolated areas of the Danube Delta are still relatively pristine, with few microplastic particles in some of the sediments sampled.

scholarly journals Spatio-temporal variations of lateral and atmospheric carbon fluxes from the Danube Delta

2020 ◽  
Author(s):  
Marie-Sophie Maier ◽  
Cristian R. Teodoru ◽  
Bernhard Wehrli
Keyword(s):  
Surface Area ◽  
Black Sea ◽  
Carbon Emissions ◽  
Danube River ◽  
The Black Sea ◽  
Danube Delta ◽  
Carbon Turnover ◽  
Carbon Yield ◽  
River Deltas ◽  
Net Export

Abstract. River deltas with their mosaic of ponds, channels and seasonally inundated areas act as the last continental hotspots of carbon turnover along the land-ocean aquatic continuum. There is increasing evidence for the important role of riparian wetlands in the transformation and emission of terrestrial carbon to the atmosphere. The considerable spatial heterogeneity of river deltas, however, forms a major obstacle for quantifying carbon emissions and their seasonality. While river reaches crossing the delta can serve as reference systems, delta lakes are often dominated by aquatic production and channels act as collection systems for carbon exported from adjacent wetlands. In order to quantify carbon turnover and emissions in the complex mosaic of the Danube Delta, we conducted monthly field campaigns over two years at 19 sites spanning river reaches, channels and lakes. Here we report greenhouse gas fluxes (CO2 and CH4) from the freshwater systems of the Danube Delta and present the first seasonally resolved estimates of its freshwater carbon emissions to the atmosphere. Furthermore, we quantify the lateral carbon transport of the Danube River to the Black Sea. We estimate the delta’s CO2 and CH4 emissions to be 65 GgC yr−1, of which about 8 % are released as CH4. The median CO2 fluxes from river branches, channels and lakes are 25, 93 and 5.8 mmol m−2 yr−1, respectively. Median total CH4 fluxes amount to 0.42, 2.0 and 1.5 mmol m−2 yr−1. While lakes do have the potential to act as CO2 sinks in summer, they are generally the largest emitters of CH4. Small channels showed the largest range in emissions including a CO2 and CH4 hotspot sustained by adjacent wetlands. The channels thereby contribute disproportionately to the delta’s emissions considering their limited surface area. In terms of lateral export, we estimate the net export of the Danube Delta to the Black Sea to about 160 GgC yr−1, which only marginally increases the carbon load from the upstream river catchment (8490 GgC yr−1) by about 2 %. While this contribution of the delta seems small, deltaic carbon yield (45.6 gC m−2 yr−1, net export load/surface area) is about 4-fold higher than the riverine carbon yield from the catchment (10.6 gC m−2 yr−1).

scholarly journals Spatio-temporal variations in lateral and atmospheric carbon fluxes from the Danube Delta

2021 ◽  
Vol 18 (4) ◽  
pp. 1417-1437
Author(s):  
Marie-Sophie Maier ◽  
Cristian R. Teodoru ◽  
Bernhard Wehrli
Keyword(s):  
Organic Carbon ◽  
Surface Area ◽  
Black Sea ◽  
Carbon Emissions ◽  
Danube River ◽  
The Black Sea ◽  
Danube Delta ◽  
Carbon Turnover ◽  
Carbon Yield ◽  
River Deltas

Abstract. River deltas, with their mosaic of ponds, channels and seasonally inundated areas, act as the last continental hot spots of carbon turnover along the land–ocean aquatic continuum. There is increasing evidence for the important role of riparian wetlands in the transformation and emission of terrestrial carbon to the atmosphere. The considerable spatial heterogeneity of river deltas, however, forms a major obstacle for quantifying carbon emissions and their seasonality. The water chemistry in the river reaches is defined by the upstream catchment, whereas delta lakes and channels are dominated by local processes such as aquatic primary production, respiration or lateral exchange with the wetlands. In order to quantify carbon turnover and emissions in the complex mosaic of the Danube Delta, we conducted monthly field campaigns over 2 years at 19 sites spanning river reaches, channels and lakes. Here we report on the greenhouse gas fluxes (CO2 and CH4) from the freshwater systems of the Danube Delta and present the first seasonally resolved estimates of its freshwater carbon emissions to the atmosphere. Furthermore, we quantify the lateral carbon transport of the Danube River to the Black Sea. We estimate the delta's CO2 and CH4 emissions to be 65 GgC yr−1 (30–120 GgC yr−1, a range calculated using 25 to 75 percentiles of observed fluxes), of which about 8 % are released as CH4. The median CO2 fluxes from river branches, channels and lakes are 25, 93 and 5.8 mmol m−2 d−1, respectively. Median total CH4 fluxes amount to 0.42, 2.0 and 1.5 mmol m−2 d−1. While lakes do have the potential to act as CO2 sinks in summer, they are generally the largest emitters of CH4. Small channels showed the largest range in emissions, including a CO2 and CH4 hot spot sustained by adjacent wetlands. Thereby, the channels contribute disproportionately to the delta's emissions, considering their limited surface area. In terms of lateral export, we estimate the net total export (the sum of dissolved inorganic carbon, DIC, dissolved organic carbon, DOC, and particulate organic carbon, POC) from the Danube Delta to the Black Sea to be about 160 ± 280 GgC yr−1, which only marginally increases the carbon load from the upstream river catchment (8490 ± 240 GgC yr−1) by about 2 %. While this contribution from the delta seems small, deltaic carbon yield (45.6 gC m−2 yr−1; net export load/surface area) is about 4 times higher than the riverine carbon yield from the catchment (10.6 gC m−2 yr−1).

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