An Approach for Trophic Gradient in Lake Mogan Turkey : A Shallow Eutrophic Lake

Year 2010, Volume: 38 Issue: 1, 41 - 45, 01.01.2010

Fatih Mangit Sedat V. Yerli

Abstract

Lakes become more productive as they accumulate nutrients with time and this process is called natural eutrophication which probably occurs very rarely. This natural eutrophication is generally fastened by antropogenic factors. Lake Mogan is a shallow lake with surface area 5.5 km2 in the close vicinity of Ankara, Turkey. Lake is under the recreational use. Natural process of eutrophication gained a momentum due to anthropogenic effects in the last decade. Numerous studies and suggestions have been made as well as prevention, but process is continuing as represented in this study. Lake eutrophication assessment was done in order to illustrate trophic gradient changes and its impact on zooplankton and zoobenthos. Trophic state index TSI which consists three parameters; total phosphorus orthophosphate , chlorophyll-a concentration and Secchi disc depth, is constructed. No possible trophic gradient change was observed in lake spatially but changes according to seasons are evaluated.

Keywords

Trophic status index, Ecological interactions, Lake Mogan, Turkey

References

• Moss, B., Ecology of fresh waters: Man and Medium, 2nd edition. Blackwell Scientific Publications, Oxford, 417pp., Carlson, R.E., A trophic state index for lakes. Limnology and Oceanography 22(2), 361-369, 1977.
• Pulatsü, S., Aydın, F., Water quality and phosphorus budget of Mogan Lake, Turkey. Acta Hydrochim. Hydrobiol., 25(3), , 1997.
• Manav, E., Yerli, S.V., An Assesment on the trophic status of Lake Mogan, Turkey. Fresenius Envir. Bull., 17(1), 3, Mangıt, F., Monitoring of the trophic status of Lake Mogan. MSc Thesis, Turkey: Hacettepe University, 44 pp., 2008.
• Greenberg, A.E., Trussel, R., Clesceri, L.S., Standard Methods, (Ed.), APHA, AWWA, WPCF, American Health Association 1015 Fifteenth Street NW Washington, DC , 1272 pp., 1985.
• ICES, Zooplankton methodology manual, (Ed.) Harris R.P., Wiebe, P.H., Lenz, J., Skjoldal, H.R., Huntley, M., Academic Press, 684 pp., 2000.
• Welch, P.S., Limnological methods, McGraw-Hill Book Company, 381pp., 1948.
• Edmondson, W.T. , Freshwater Biology. 2nd Editon. John Wiley and Sons Inc. New York, 420, 1959.
• Kolisko, R.A., Plankton rotifers, biology and taxonomy, Science Publishers, Stuttgart 146 pp., 1974.
• Koste, W., Rotatoria. Die Rädertiere Mitteleuropas begründet von Max Voigt, 2. Gebrüder Borntraeger, Berlin, Stuttgart, 637 pp., 1978.
• Yerli, S.V., Gündüz, E., Akbulut, A., Trophic status of Sultan Marshes, Turkey. Fresenius Envir. Bull. 6, 97, 1997.
• Wetzel, R.G., Limnology, 2nd edition. CBS College Publishing, 767pp., 1983.
• Berzins, B., Pejler, B., Rotifer occurrence in relation to temperature. Hydrobiologia, 175, 223, 1989.
• Berzins, B., Pejler, B., Rotifer occurrence in relation to oxygen content. Hydrobiologia, 183, 165, 1989.
• Burnak, S.L., Beklioğlu, M., Macrophyte-dominated clearwater state of Lake Mogan. Turk. J. Zool., 24, 305, Bays, J.S., Zooplankton/trophic state relationships and the potential for prediction of ecosystem structure in reclaimed Florida lakes. Proceedings of the tenth annual conference on wetlands retoration and creation, Proceed (Ed.), 17, Szlauer, B., Zooplankton based assessment of the Lake Miedwie (North-Western Poland) trophic status. EJPAU, (1), 1999.
• Herzig, A., The Analysis of planktonic rotifer populations: A plea for long term investigations. Hydrobiologia, 147, 163,1987.