Preliminary results of Phytoplankton in Zaghen Polder, Danube Delta Biosphere Reserve

Zaghen polder is a wetland of faunistic, landscape and recreational area for Tulcea town and the surrounding turism attraction. The phytoplankton analisys consisted in sample prelevation and measurements in four points in polder area. Measurements on phytoplankton amount were made with submersible spectrofluorometer, wich uses light intensity to differentiate the main algal groups and quantifying their biomass. Qualitative analysis of phytoplankton from samples taken from the Zaghen polder was done using the Leitz Laborlux S microscope. The analyses have identified chlorophyll values ranging from 12.41 µg/L in sample point 1 (14.06.2017), and 457.97 µg/L in sample point 3 (27.07.2017). According to Order 161 / 16.02.2006 issued by Ministry of Environment and Water Management it shows that the average grade class was the third, having a mesotrophic degree, with values between 50-100 μg/L. The qualitative analisys reveal 39 genus belonging to 4 taxonomic groups as follow: 17 Chlorophceae, 3 Cyanophyceae, 16 Diatoms and 3 Euglenophyceae. The lowest number of individuals per liter was identified in 14.06.2017 respectively 154,958 ind/L in sample point 1, and the highest number of individuals per liter in 28.08.2017, in sample point 2, respectively 3,388,430 ind/L. The data presented above represent a preliminary analisys on phytoplankton in first year after the ecological rehabilitation of the area.