The Effect of Environmental Factors on the Growth and size Structure of two Dominant Phytoplankton Species in the Büyükçekmece Reservoir (İstanbul,Turkey)

The aim of this study was to investigate seasonal variability in the growth and size structure of dominant phytoplankton species in Büyükçekmece Reservoir, and to determine the environmental factors that affect morphological plasticity in those dominant species. In total, 78 taxa from 8 algal divisions were identified. Bacillariophyta and Chlorophyta were the most important divisions with respect to species number, but cryptomonads Plagioselmis nannoplanctica (Skuja) Novarino, Lucas, and Morrall, and a Cryptomonas sp. were dominant in terms of density and biomass. P. nannoplanctica was the major contributor of biomass in the reservoir. A significant difference in Plagioselmis species biovolume was observed between winter-early spring and summer. A significant negative correlation was observed between its seasonal size structure and abundance. During winter (December 2004-April 2005) nutrient values were higher than during autumn (October-Novermber 2005) and P. nannoplanctica had maximum cell size (17.5 mm x 10 µm; biovolume: 589.5 mm3), but its abundance was very low (< 6 cells × 103 l-1). The minimum surface:volume ratio (SA/V: 0.87) was recorded in this period. Among the measured environmental factors, water temperature was the only parameter that had a statistically significant negative relationship (R2: 0.635; P < 0.01) with P. nannoplanctica cell size. The results indicate that seasonal changes in cryptomonad size structure were controlled by water temperature.

Anahtar Kelimeler:

Key words: Cryptomonads, surface-volume ratio, environmental factors, Büyükçekmece Reservoir

The Effect of Environmental Factors on the Growth and size Structure of two Dominant Phytoplankton Species in the Büyükçekmece Reservoir (İstanbul,Turkey)

Keywords:

Key words: Cryptomonads, surface-volume ratio, environmental factors, Büyükçekmece Reservoir,

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Naselli-Flores L, Barone R. Pluriannual morphological variability of phytoplankton in a highly productive Mediterranean reservoir (Lake Arancio, Southwestern Sicily). Hydrobiologia 578: 47-57, 2007.
Morabito G, Oggioni A, Caravati E et al. Seasonal morphological plasticity of phytoplankton in Lago Maggiore (N. Italy). Hydrobiologia 578: 47-57, 2007.
O’Farrell I, Pinto PT, Izaguirre I. Phytoplankton morphological response to the underwater light conditions in a vegetated wetland. Hydrobiologia 578: 47-57, 2007.
Stoyneva MP, Descy JP, Vyverman W. Green algae in Lake Tanganica: is morphological variation a response to seasonal changes? Hydrobiologia 578: 7-16, 2007.
Salmaso N, Padisak J. Morpho-functional groups and phytoplankton development in two deep lakes (Lake Garda, Italy and Lake Stechlin, Germany). Hydrobiologia 578: 47-57, 2007.
Aktan Y, Okgerman H, Gürevin C et al. Phytoplankton development and its relationships with zooplankton and environmental parameters in Büyükçekmece Reservoir, Turkey. Symposium for European freshwater sciences (SEFS-5), Palermo, Italy: 2007: pp168.
Nusch EA. Comparison of different methods for chlorophyll and phaeopigment determination. Archiv für Hydrobiol./ Ergebnisse der Limnol. 14: 14-36, 1980.
APHA-AWWA, WPCF. Standard methods for the examination of water and wastewater. 17th edition, American Public Health Association, Washington DC; 1989: pp. 1268.
Huber- Pestalozzi G. Das Phytoplankton des Suβwassers, Systematik und Biologie, 3. Teil: Cryptophyceen, Chloromonadinen, Peridinean. E. Schweizerbarth’sche Verlagsbuchhandlung, Stuttgart; 1950: pp. 310.
Novarino G. Phylum Cryptophyta (Cryptomonads). In: John DM, Whitton BA, Brook AJ ed. The freshwater algal flora of the British Isles, Cambridge; 2002: pp 180-185.
Novarino G. A companion to the identification of cryptomonad flagellates (Cryptophyceae=Cryptomonadea). Hydrobiologia 502:225-270, 2003.
Utermöhl H. Zur vervollkommnung der quantitativen phytoplankton methodic. Mitt. Int. Ver. Limnol. 9: 1-38, 1958.
Hillebrand H, Dürselen CD, Kirschtel D et al. Biovolume calculation for pelagic and benthic microalgae. Journal of Phycology 35: 403-424, 1999.
Willén E, Oké M, Gonzales F. Rhodomonas minuta and Rhodomonas lens (Cryptophyceae): Aspects on Form-variation and ecology in Lakes Mälaren and Vättern, Central Sweden. Acta Phytogeogr. Suec. 68: 163-172, 1980.
Barone R, Naselli-Flores L. Distribution and seasonal dynamics of Cryptomonads in Sicilian water bodies. Hydrobiologia 502: 325-329, 2003.
Reynolds CS. The ecology of freshwater phytoplankton. Cambridge University Press, Cambridge; 1984: pp. 384.
Naselli-Flores L, Barone R. Phytoplankton dynamics and structure: a comparative analysis in natural and man-made water bodies of different trophic state. Hydrobiologia 438: 65- 74, 2000.
Van Donk E. Defenses in phytoplankton against grazing induced by nutrient limitation, UV-B stress and infochemicals. Aquatic ecology 31: 53-58, 1997.