Romanescu G.T.,Al. I. Cuza University |
Dinu C.I.,Eco Museal Research Institute Tulcea |
Radu A.L.,Eco Museal Research Institute Tulcea |
Torok L.I.,Danube Delta National Institute for Research and Development
Carpathian Journal of Earth and Environmental Sciences | Year: 2010
Abstract: The altimetric and granulommetric proofs, as well as their shape, include them in the category of typical fluviatile limans from this point of view. The four analysed lakes contain fresh water with a higher mineralization than the Danube. The increase of concentration corresponds to the periods in which the connection with the river is interrupted. The marshes Vederoasa and Iortmac have a higher salt content due to underground supply. Due to its chemical properties, the water of all marshes are included in the class of bicarbonated waters - calcium group, when they are supplied by the Danube, or sodium group, when the connection with the river is interrupted and a chemical metamorphosis process takes place (Bugeac, Oltina, Dunareni marshes), or magnesium group when water supply comes from own sources (Vederoasa, Iortmac and Baciu marshes). The structure of vegetation in the lacustrine cuvettes included five aquatic associations and four swamp associations. The lakes vegetation cover degree has percentages between 10-90%. The greatest plankton amount is found at the junction between the lakes and the supply channels coming from the Danube. The reduced species diversity reflects the answer of the fish population to the changes of the environmental conditions.
Romanescu G.,Al. I. Cuza University |
Dinu C.,Eco Museal Research Institute Tulcea |
Radu A.,Eco Museal Research Institute Tulcea |
Stoleriu C.,Al. I. Cuza University |
And 2 more authors.
International Journal of Conservation Science | Year: 2013
The fluviatile limans in the south-west of Dobrogea are the most characteristic forms of this type, with an exclusive development on the territory of Romania. In time, they were interpreted as fluvio-maritime limans or even as fluvio-lacustrine limans. As a result of the fact that they are situated close to the Danube, bordering one of the driest regions of Romania, they have had diverse usage since ancient times. Because the fluviatile limans in Dobrogea are mostly used in pisciculture, the water qualitative parameters have to be monitored permanently. They also have a role in attenuating floods, acting as a tampon against flash floods. Consequently, they have a special local importance even today, feeding as much of the population as possible (directly or indirectly). From a geomorphological point of view the fluviatile limans in Dobogea were formed as a result of the withdrawal of the Romanian (Levantine). The decrease in depth may cause the flood waves to pass over the dams. In this case, the periodical drainage of lake cuvettes is required. The physical parameters of water (depth, transparency and temperature) as well as the chemical parameters (pH, dissolved oxygen, nitrates, nitrites, phosphates and the Ca/Mg ratio) have been analyzed. From an ecological viewpoint, the fluviatile limans in the south-west of Dobrogea are suitable for fish breeding and for developing an adequate lacustrine life.