Research of phytoplankton is conducted in different seasons during 2004 and 2005. River Bojana and Ada Bojana are analyzed on several locations. The objective of research is based on algae as reliable indicator of water quality and ecological condition of water. We would like to show the need for protection of these water ecosystems from permanent contamination, basically sewage waste. Saprobiotic index is determined by Gulyas Pal method. Pantle Buck method is used to calculate saprobiotic level. Chlorophyll A is analyzed by spectrophotometer. Presence of Cyanophytae was established.

Influence of eutrophication to the phytoplankton community were studied in the inner part of Boka Kotorska Bay (Kotor Bay and Risan Bay) from September 2003 to August 2004. Kotor Bay and Risan Bay is very interesting area because the influence of natural and anthropogenic eutrophication are mixed very often. Microphytoplankton density is high (greater than 10**6 cells/cubic dm) what is characteristic eutrophic area, to the highest eutrophic area (greater than 10**7 cells/cubic dm). These values we stated in the surface, because in this layer were the best conditions. In same time we stated very high values: SiO2, oxygen saturation and chlorophyll a. The conclusion is: Boka Kotorska Bay and especially Kotor Bay (as a part of Boka Kotorska) has to be protected of dangerous consequences such as blooming. It is needed to regulate wastewater, their purification and permanent control physico-chemical and biological parameters, and especially phytoplankton component.

During the research of the flora of the river Moravica methodology of ass. Scirpo-Phragmitetum, Koch 1926, subass. typhetosum latifoliae, Pignotti 1953, with differential typa Typha latifolia with related marshy plants was applied. The community is developed as small units in the lower flow of the river Moravica (the part flowing through the town Aleksinac), where the anthropogenic influences are significant due to the empting of the sewage and industrial polluted waters of the town Aleksinac. Many diffuse forms of pollution are also present, particularly in the form of illegal dumps. Waste waters represent serious load on the recipient river and influence qualitative and quantitative content of the phytocenosis. Ecological index of the community shows change in water quality and presence of organic substances (above all nitrogen compounds) in the water and the riverbed ass. Scirpo-Phragmitetum, Koch 1926, subass. typhetosum latifoliae, Pignotti 1953, which indicates the riverbed loaded with organic substances (mezotrophic plants, N=3.50)