The divisions Bacillariophyta and Chlorophyta were dominant; however, Cyclotella, Navicula, Nitzschia and Synedra of Bacillariophyta, and Chlorella and Scenedesmus of Chlorophyta were abundant. Chlorophyll a reached its maximum levels during June and September 1996 and May 1997, corresponding to the maximum values of orthophosphate, sulphate, calcium and temperature in the lake. | Turk J Bot 30 (2006) 349-357 © TÜB‹TAK Research Article Seasonal Variation of Phytoplankton and Value of Chlorophyll a in the Sar›yar Dam Reservoir (Ankara, Turkey) Tahir ATICI1, Olcay OBALI2 1 Gazi University, Gazi Education Faculty, Biology Department, 06500, Beflevler, Ankara - TURKEY E-mail: tahir@ 2Ankara University, Science Faculty, Biology Department, 06500, Tando¤an, Ankara - TURKEY E-mail: Received: Accepted: Abstract: The phytoplanktonic algae were determined in samples taken from 7 different locations at the Sar›yar Dam Reservoir (SDR) from March 1996 to June 1997. The seasonal variation of phytoplankton and their chlorophyll a were determined and contents were discussed in relation to the physical and chemical parameters of the water. The divisions Bacillariophyta and Chlorophyta were dominant; however, Cyclotella, Navicula, Nitzschia and Synedra of Bacillariophyta, and Chlorella and Scenedesmus of Chlorophyta were abundant. Chlorophyll a reached its maximum levels during June and September 1996 and May 1997, corresponding to the maximum values of orthophosphate, sulphate, calcium and temperature in the lake. Key Words: Phytoplankton, Algae, Sar›yar Dam Reservoir, Seasonal variation, Chlorophyll a Sar›yar Baraj› (Ankara/TÜRK‹YE) Fitoplanktonunun Mevsimsel De¤iflimi ve Klorofil-a De¤erleri Özet: Sar›yar Baraj Gölü fitoplanktonik algleri Mart 1996- Haziran 1997 tarihleri aras›nda belirlenen yedi istasyondan al›nan örneklerde incelenmifltir. Fitoplanktonun mevsimsel de¤iflimi ve klorofil- a miktar› belirlenerek suyun fiziksel ve kimyasal verileriyle iliflkilendirilmifltir. Bacillariophyta ve Cholorophyta divizyolar› bask›n organizmalard›r. Bacillariophyta dan Cyclotella, Navicula, Nitzschia ve Synedra, Chlorophyta dan da Chlorella ve Scenedesmus üyeleri yayg›n durumdalard›r. Klorofil-a de¤erleri Haziran, Eylül 1996 ve May›s 1997 de maksimum seviyeye ulaflm›flt›r. Ayn› dönemlerde gölde .
