Algae and their seasonal variations in the littoral region of Lake Hazar between Sivrice town and Behrimaz stream

ABSTRACT Ph.D. Thesis ALGAE AND THEIR SEASONAL VARIATIONS IN THE LITTORAL REGION OF LAKE HAZAR BETWEEN SİVRİCE TOWN AND BEHRİMAZ STREAM Feray ÖZRENK SÖNMEZ Fırat University Fen Bilimleri Enstitüsü Graduate School of Natural and Applied Sciences Department of Aquaculture 2003, Page: 130 In this study, algae occurring in phytoplankton and phytobenthos and their seasonal variations were investigated in monthly samples taken from four stations in the littoral region of Lake Hazar between Sivrice Town and Behrimaz Stream for a period of a year. A total of 94 algal taxa belonging to Bacillariophyta (S4), Chlorophyta (7), Cyanophyta (2) and Dinophyta (Î) were recorded during the study. Diatoms (Bacuîariophyîa) were the most significant both in phytoplankton and phytobenthos in terms of number of taxa and frequency of occurrence. Members of green algae (Chlorophyta), clue-green algae (Cyanophyta) and Dinophyta were also recorded with less numbers of taxa and individuals compare to diatoms both in phytoplankton and phytobenthos. Although diatoms occurred in all seasons their highest numbers were encountered in the summer. Number of taxa in phytoplankton (47) were less than those recorded in epilithon and epipsammon (80). Epilithic forms usually reached to higher relative abundance than epipsammic and planktonic algae. Growth of algae in summer were more conspicious than those observed in other seasons. Trophic level of the littoral region of Lake Hazar investigated in this study was discussed in relation to chemical and biological findings. Anahtar Kelimeler : Phytoplankton, Phytobenthos, Littoral, Lake Hazar, Elazığ. U