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Generally, water quality involves the water-s physical-chemical and biological attributes that depend on the natural surrounding environment and anthropogenic impacts. Through the years, the river water quality in the Sf. Gheorghe Branch has been subjected to various hydro-sedimentary impacts, due to the anthropogenic meander cut-off plans initiated for navigational objectives. In this study, the Sf. Gheorghe Branch water quality evaluation was performed using in-situ observations, measurements, and datasets provi...

The Danube Delta is a wetland of global importance, providing several ecosystem services. The sustainable development (i.e., economic, social and environmental) in the area depends on the health, quality and quantity of the natural resources. Water is one of the most important resources. Largely, the Danube Delta, which receives the input of water and sediment flux from the Danube River, gathered form its entire basin, may experiences lower water quality due to natural and anthropogenic factors, from basin to loca...

This paper presents the findings of the mapping and evaluation of macrophyte vegetation from Tataru and Uzlina lakes, located within Danube Delta, Romania. Throughout time, the Danube Delta unique ecosystem has endured considerable ecological changes due to natural and anthropogenic stressors. Currently, the potential threats are those related to pollution, agriculture, land use, climate change and subsequently, the proliferation and/or the extinction of many macrophyte species. The excessive development of aquati...

The paper presents the results of the water quality of the St. George branch, one of three Danube River distributaries, using the combined physical and chemical analyses from June 2017. Three cutoff meander reaches (the Mahmudia, Upper Dunavat and Lower Dunavat meanders) were selected to assess the water ecological state. The cut-offs of the meanders by navigational canals since 1984-1988 caused significant changes in the distribution of the water discharge. Water samples were acquired throughout several cross-sec...

Several geochemical analyses (bulk parameters, particle size, loss on ignition, major, minor and trace elements) were performed on 51 recent sediment samples collected in May 2022 from Rosulet, Rosu and Puiu lakes which are located in the fluvio-marine delta plain of the Danube Delta, Romania. The aim of this study was to decipher the potential origin of anthropogenic and/or natural sources, weathering, sedimentary processes and the local geochemical fingerprint on the distribution of specific chemical elements in...

The study presents a detailed analyse of the morpho-dynamic processes of the main two bifurcations of the Danube River within its delta, at Ceatal Izmail and Ceatal St. George. The first bifurcation of the Danube, called Ceatal Izmail; here the river divides into two distributaries: a northern one, the Chilia (Kilia), and a southern one, the Tulcea. Forking to the right at Ceatal Izmail (Mile 43), the Tulcea distributary stretches further to 17 km to the second main hydrographic knot Ceatal Sfantu Gheorghe (St. Ge...

The quality and quantity of delta lakes- sediment depend on fluvial input and in-situ bio-geo-chemical processes. The present study investigates the quality of lacustrine sediments collected from two lakes - Tataru and Merhei, situated in different hydrodynamic environments within the Danube Delta, Romania, but both connected to fluvial input of water and sediment of the Danube. The following physical and chemical analyses have been carried out on several lake-bottom sediment samples: the main lithological compone...

This paper aims to assess the trend of river morphological evolution and changes in the Danube riverbed sector, i.e., Ceatal Izmail, using GIS techniques. The sector is located on the Danube at Mile 43, where the river branches into Chilia and Tulcea tributaries. Therefore, three monitoring topo-bathymetric profiles (2018 and 2019) were performed on Danube (Mm 43), Chilia (Km 114) and Tulcea (Mm 42.5), under circumstances of high and low water levels. On the Danube (Mm 43), an asymmetry of the valley (right bank) ...

Asellus aquaticus Linnaeus, 1758 is the widespread and common Palearctic freshwater isopod, feeding on detritus. This crustacean, probably, has its ancient evolutionary origins around Siberia and has spread from there to Western Europe and North America. Commonly associated with a temperate climate, it has been recorded as far south as the Mediterranean, and as far north as Scandinavia. The species is primarily associated with the b-mesosaprobic waters of the palearctic realm i.e., high concentrations of dissolved...

Natural processes and human influences can cause several environmental issues upon urban and rural aquatic systems, especially in deltaic environs. This study was aimed to assess the vertical variation in the physical-chemical and lithological characteristics of core sediments. 14 undisturbed short sediment cores were collected from soft lacustrine sediments in various shallow lakes situated in the Matita-Merhei interdistributary depression, Danube Delta, Romania. Sediment samples were measured for temperature, pH...

Water quality was investigated in Lake Matita, part of the Danube Delta Biosphere Reserve, Romania, to assess the overall status of the freshwater ecosystem, in accordance with the EU Water Framework Directive (WFD ? 2000/60/EC), which addresses all surface waters i.e., rivers, lakes, transitional waters and coastal waters in the EU. From this perspective, a specific physical and chemical analysis of surface water samples was performed, collected in different sectors of the lake, during the summer of June 2020. Se...