ASSESSMENT OF THE ABUNDANCE AND DISTRIBUTION OF THE EMERGENT AQUATIC VEGETATION IN THE DANUBE DELTA, ROMANIA. THE CASE STUDY OF TATARU AND UZLINA LAKES

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 aquatic vegetation has negative consequences, reducing the flow velocity of water in the connecting channels, exacerbates the sedimentation processes in the deltaic lakes which are subject to the clogging phenomenon (i.e., silting). The abundance, distribution and biodiversity of the emergent aquatic species were surveyed in Tataru and Uzlina lakes. The biodiversity of macrophytes is different in the investigated lakes, being dependent on the fluvial input of water and sediment of the Danube River, extent of lakes and water depth. In Tataru Lake, the macrophyte vegetation was represented by a greater variety of species (Nymphaea alba, Nuphar lutea, Trapa natans, Salvinia natans, Lemna minor and Phragmites australis), in comparison to Uzlina Lake (Nymphaea alba, Nuphar lutea, Trapa natans and Phragmites australis). This methodology and results are valuable for the strategic environmental assessment and management of the Danube Delta Biosphere Reserve and can be used in similar settings.