Structure and the Development of the Phytoplankton (2001 - 2003) in the Bulgarian Wetlands, North Part of the Black Sea

Institute of Fisheries and Aquaculture, Varna, BG - 9000 Varna, Bulgaria


PETROVA, D., 2006. Structure and the Development of the Phytoplankton (2001-2003) in the Bulgarian Wetlands, North Part of the Black Sea. Bulg. J. Agric. Sci., 12: 261-267

The interest to the Bulgarian wetlands and the problems related to them increased in the last few years. It implies a new understanding of the role and the importance of the wetlands apart from they being used as resources. The dynamic in the phytoplankton development in Durankulak and Shabla lakes enable the evaluation of the rate of the eutrophication of the system and assessing the trophic state of the wetlands under investigation. Thus the phytoplankton, being the first target of nutrient alterations, is considered to be a decisive factor for the quality of the lake water and that of the ecosystem's health. The samples were collected in April - June-September 2001-2003 in the surface waters. The present paper aims at characterizing more thoroughly the qualitative and quantitative structure of the phytoplankton, to determine the dominants species, to retrace seasonal dynamics of phytocenosis of the Bulgarian Black Sea wetlands. The abundance and the biomass of the phytoplankton increased from April to September during the whole period of the investigation. The biomass predominantly was formed of Chlorophyceae, Euglenophyceae and Diatoms species.

Key words: wetlands, Black Sea, lakes, phytoplankton, density, biomass
Abbreviations: DL-GO (Durankulak Lake-Golymo Ogledalo); DL-O (Durankulak Lake - Ostrova); DL-OB (Durankulak Lake - Orlovo blato); SL-N (Shabla lake-North); SL-S (Shabla lake-South); SL-EE (Shabla lake-Ezerets East); SL-EW (Shabla lake-Ezerets West); SL-ST (Shabla lake-Shabla Tuzla)