Affiliation:
1. National Research and Development Institute for Marine Geology and Geoecology, GeoEcoMar
Abstract
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 components (total organic matter-TOM%, total carbonates-CAR% and siliciclastic fraction-SIL%), particle size analysis and technophilic element contents. The lithological analysis reveals a considerable variation related to the TOM%, CAR% and SIL% fractions. From this perspective, the investigated lacustrine sediments are generally characterized as organic-rich sediments (endogenous input). The grain size analysis shows the predominance of sandy silt sediments in both lakes. The data regarding the content of technophilic elements in the bed-sediment samples is given in comparison with their natural geochemical background reference value and their acceptable limits provided by the national reference standard. The general characterization of the investigated sediments reveals slight differences among the two investigated lakes in terms of the sediment input from the Danube River. The acquired results contribute to improve the knowledge about physical and chemical characteristics of lacustrine sediments and to plan management strategies of the deltaic lakes for future conservation perspectives, considering the great international importance of the Danube Delta Biosphere Reserve.