PRELIMINARY ASPECTS OF DIVERSITY PLANKTON THE SALT LAKE, BRAILA COUNTY

Adina Popescu, Daniela Ibanescu

Abstract
    Salt Lake, located 16 m above sea level, is an old course of Danube, now stuck in the south of county of Braila. The biological samples were collected in May 2013 from four points, denoted by S1, S2 (in the climatic health resort) and S3, S4 (in the sources). The plankton analysis was performed using stereomicroscope, using an extensive literature (key determinations, atlases etc.). For the structural characterization of biological samples, in a quantitative perspective, were especially calculated the following parameters: number density, numerical abundance. The diversity analysis of biological samples was quantified using Shannon-Wiener index (HS). The phytoplankton is represented by plants that have a simple organization: Cyanophyceae, Bacillariophyceae, and Chlorophyceae, which can withstand unfavorable conditions of life. A total of 13 species of phytoplankton have been identified in the four stations studied. From a quantitative perspective, Bacillariophiceae dominated them, accounting for 59.74-69.49%, followed by Cyanophyceae accounting for 30.51-36.71% and Chlorophyceae accounting for 0-6.49%. The zooplankton is represented by a crustacean Artemia salina. The number of individuals located in different ontogenetic stages preadulte generally exceeded 10-20 times the number of adult individuals of Artemia salina. The Shannon-Wiener index values in the analyzed stations were comparable. The plankton of the Salt Lake is poor in species.

Key words: Salt Lake, plankton, species, diversity