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Estonian Journal of Earth Sciences
ISSN 1736-7557 (Electronic)
ISSN 1736-4728 (Print)
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A radical shift from soft-water to hard-water lake: palaeolimnological evidence from Lake Kooraste Kõverjärv, southern Estonia; pp. 317–327

Full article in PDF format | doi: 10.3176/earth.2012.4.10

Tiiu Alliksaar, Atko Heinsalu


The Water Framework Directive (WFD) of the European Union requires the quality of all European water bodies to be examined, and aims to achieve good status by 2015. This study was initiated to assess whether a potential reference lake for identifying lake-type specific reference conditions meets the WFD requirements, of being minimally impacted by human activity during the last centuries. The sediments of Lake Kooraste Kõverjärv were analysed for diatom assemblages and sediment composition; past changes in the lake-water pH and total phosphorus were reconstructed, using quantitative models on sedimentary diatoms. The chronology of sediments was established, using spheroidal fly-ash particles stratigraphy. Palaeolimnological investigations, supported by information from historical maps, revealed that man-made changes around the lake have severely influenced its ecological conditions. The lake, which had been oligotrophic with soft and clear water before the mid-17th century, has been trans­formed into a hard-water lake by modifications to the inflow and outflow. The lake water quality has also been altered by the infiltration of nutrients from a nearby hypertrophic lake that was used for flax retting since the 19th century. Although the ecological status of the lake has remained good despite all these changes, it is still questionable whether to nominate it as a reference lake for stratified hard-water lake types.


Alliksaar, T., Hörstedt, P. & Renberg, I. 1998. Characteristic fly-ash particles from oil shale combustion found in lake sediments. Water, Air and Soil Pollution, 104, 149–160.

Alliksaar, T., Heinsalu, A., Saarse, L., Salujõe, J. & Veski, S. 2005. A 700-year decadal scale record of lake response to catchment land use from annually laminated lake sediments in southern Estonia. Verhandlungen der Internationalen Vereinigung für Theoretische und Angewandte Limnologie, 29, 457–460.

Battarbee, R. W., Juggins, S., Gasse, F., Anderson, N. J., Bennion, H. & Cameron, N. G. 2000. European Diatom Database (EDDI). An Information System for Palaeo­environmental Reconstruction. In European Climate Science Conference, Vienna City Hall, Vienna, Austria, 19.–23. October 1998, pp. 1–10.

Battarbee, R., Jones, V. J., Flower, R. J., Cameron, N. G., Bennion, H., Carvalho, L. & Juggins, S. 2001. Diatoms. In Tracking Environmental Change Using Lake Sediments. Volume 3: Terrestrial, Algal, and Siliceous Indicators (Smol, J. P., Birks, H. J. B. & Last, W. M., eds), pp. 155–202. Kluwer Academic Publishers, Dordrecht.

Bennion, H. & Battarbee, R. 2007. The European Union Water Framework Directive: opportunities for palaeo­limnology. Journal of Paleolimnology, 38, 285–295.

Bennion, H., Fluin, J. & Simpson, G. L. 2004. Assessing eutrophication and reference conditions for Scottish freshwater lochs using subfossil diatoms. Journal of Applied Ecology, 41, 124–138.

Bennion, H., Johnes, P., Ferrier, R., Phillips, G. & Haworth, E. 2005. A comparison of diatom phosphorus transfer functions and export coefficient models as tools for reconstructing lake nutrient histories. Freshwater Biology, 50, 1651–1670.

Bennion, H., Battarbee, R. W., Sayer, C. D., Simpson, G. L. & Davidson, T. A. 2011. Defining reference conditions and restoration targets for lake ecosystems using palaeo­limnology: a synthesis. Journal of Paleolimnology, 45, 533–544.

Bjerring, R., Bradshaw, E. G., Amsinck, S. L., Johansson, L. S., Odgaard, B. V., Nielsen, A. B. & Jeppesen, E. 2008. Inferring recent changes in the ecological state of 21 Danish candidate reference lakes (EU Water Framework Directive) using palaeolimnology. Journal of Applied Ecology, 45, 1566–1575.

Björck, S. & Wohlfarth, B. 2001. 14C chronostratigraphic techniques in paleolimnology. In Tracking Environ­mental Change Using Lake Sediments. Volume 1: Basin Analysis, Coring and Chronological Techniques (Last, W. M. & Smol, J. P., eds), pp. 205–245. Kluwer Academic Publishers, Dordrecht.

Carvalho, L., Solimini, A. G., Phillips, G., Pietilainen, O.-P., Moe, J., Cardoso, A. C., Solheim, A. L., Ott, I., Sondergaard, M., Tartari, G. & Rekolainen, S. 2009. Site-specific chlorophyll reference conditions for lakes in Northern and Western Europe. Hydrobiologia, 633, 59–66.

[EC] European Commission. 2003. River and Lakes – Typology, Reference Conditions and Classification Systems. Common Implementation Strategy for the Water Framework Directive (2000/60/EC). Guidance Document 10. European Commission, 86 pp.

[EU] European Union. 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal, L 327, 1–71.

Hall, R. I. & Smol, J. P. 1999. Diatoms as indicators of lake eutrophication. In The Diatoms: Application for the Environmental and Earth Sciences (Stoermer, E. F. & Smol, J. P., eds), pp. 128–168. University Press, Cambridge.

Heinsalu, A. & Alliksaar, T. 2009a. Palaeolimnological assess­ment of environmental change over the last two centuries in oligotrophic Lake Nohipalu Valgjärv, southern Estonia. Estonian Journal of Earth Sciences, 58, 124–132.

Heinsalu, A. & Alliksaar, T. 2009b. Palaeolimnological assess­ment of the reference conditions and ecological status of lakes in Estonia – implications for the European Union Water Framework Directive. Estonian Journal of Earth Sciences, 58, 334–341.

Heinsalu, A., Alliksaar, T., Leeben, A. & Nõges, T. 2007. Sediment diatom assemblages and composition of pore-water dissolved organic matter reflect recent eutrophication history of Lake Peipsi (Estonia/Russia). Hydrobiologia, 584, 133–143.

Heinsalu, A., Luup, H., Alliksaar, T., Nõges, P. & Nõges, T. 2008. Water level changes in a large shallow lake as reflected by the plankton:periphyton-ratio of sedimentary diatoms. Hydrobiologia, 599, 23–30.

Heiri, O., Lotter, A. F. & Lemcke, G. 2001. Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results. Journal of Paleolimnology, 25, 101–110.

Juggins, S. 2001. The European Diatom Database, User Guide. University of Newcastle, 72 pp. [].

Kolada, A., Soszka, H., Cydzik, D. & Golub, M. 2005. Abiotic typology of Polish lakes. Limnologica, 35, 145–150.

Laws, E. A. 1993. Aquatic Pollution. John Wiley & Sons Inc., 624 pp.

Leeben, A., Alliksaar, T., Heinsalu, A., Lepane, V. & Veski, S. 2008. Tracking changes in the organic matter in a lake palaeoecosystem: a spectrophotometric approach. Organic Geochemistry, 39, 915–918.

Leira, M., Jordan, P., Taylor, D., Dalton, C., Bennion, H., Helen, R., Rose, N. & Irvine, K. 2006. Assessing the ecological status of candidate reference lakes in Ireland using palaeolimnology. Journal of Applied Ecology, 43, 816–827.

Lill, E. 1988. Otepää kõrgustiku järvede seisund ja muutumine zooplanktoni põhjal. In Loodusteaduslikke meetodeid Eesti arheoloogias [Scientific Methods in Estonian Archaeology] (Rõuk, A.-M. & Selirand, J., eds), pp. 114–134. Eesti NSV Teaduste Akadeemia Ajaloo Instituut, Tallinn [in Estonian].

Loopmann, A. (ed.). 1984. Suuremate Eesti järvede morfo­meetrilised andmed ja veevahetus [Morphometrical Data and Water Exchange of Larger Estonian Lakes]. Eesti NSV Teaduste Akadeemia, Tallinn, 150 pp. [in Estonian].

Mäemets, A. 1977. Eesti NSV järved ja nende kaitse [Lakes of the Estonian S.S.R. and Their Protection]. Valgus, Tallinn, 263 pp. [in Estonian, with English summary].

[ME] Ministry of the Environment. 2009. Procedure for the Establishment of Bodies of Surface Water and a List of the Bodies of Surface Water the State of Which is to be Established, Classes of the States and the Values of Quality Indicators Corresponding to These State Classes, and the Procedure for the Establishment of the Classes of State (RTL 2009, 64, 941). Order from 28.07.2009 No. 44. Ministry of the Environment, 11 pp.. ( , [in Estonian].

Milius, A. 1992. A survey of water transparency in small lakes of South-East Estonia. Proceedings of the Estonian Academy of Sciences, Biology, 41, 216–223.

Nielsen, K., Sømod, B., Ellegaard, C. & Krause-Jensen, D. 2003. Assessing reference conditions according to the European Water Framework Directive using modelling and analysis of historical data: an example from Randers Fjord, Denmark. Ambio, 32, 287–294.[0287:ARCATT]2.0.CO;2

Nõges, T., Alliksaar, T., Heinsalu, A. & Nõges, P. 2006. A paleolimnological assessment of recent eutrophication history on large inland water body, Lake Peipsi, Estonia. Verhandlungen der Internationalen Vereinigung für Theoretische und Angewandte Limnologie, 29, 1135–1138.

Ott, I. 2006. Some principles of ecological quality classi­fication in Estonian lakes. In Proceedings of the 21th Meeting of the ICP Waters Programme Task Force in Tallinn, Estonia, October 17–19, 2005 (de Wit, H. & Skjelkvale, B. L., eds), Norwegian University of Science and Technology, 84/2006, 8–14.

Ott, I. 2008. Järve- ja jõetüüpide ökoloogilise kvaliteedi klassi­piiride interkalibreerimine 2008. a. [The Intercalibration of Lake- and River-Type Ecological Quality Class Boundaries in 2008]. Eesti Maaülikool, Põllumajandus- ja keskkonnainstituut, Limnoloogia-keskus, 58 pp. [in Estonian].

Poikāne, S., Alves, M. H., Argillier, C., van den Berg, M., Buzzi, F., Hoehn, E., de Hoyos, C., Karottki, I., Laplace-Treyture, C., Solheim, A. L., Ortiz-Casas, J., Ott, I., Phillips, G., Pilke, A., Pádua, J., Remec-Rekar, S., Riedmüller, U., Schaumburg, J., Serrano, M. L., Soszka, H., Tierney, D., Urbanič, G. & Wolfram, G. 2010. Defining chlorophyll-a reference conditions in European lakes. Environmental Management, 45, 1286–1298.

Punning, J. M., Alliksaar, T., Terasmaa, J. & Jevrejeva, S. 2004. Recent patterns of sediment accumulation in a small closed eutrophic lake revealed by the sediment records. Hydrobiologia, 529, 71–81.

Rajamäe, R., Saarse, L., Martma, T., Heinsalu, A., Poska, A. & Veski, S. 1997. Carbon geochemistry in relation to sediment chronology of Lake Kahala. Proceedings of the Estonian Academy of Sciences, Geology, 46, 42–55.

Rakko, A., Laugaste, R. & Ott, I. 2008. Algal blooms in Estonian small lakes. In Algal Toxins: Nature, Occurrence, Effect and Detection. NATO Science for Peace and Security Series A: Chemistry and Biology (Evangelista, V., Barsanti, L., Frassanito, A. M., Passarelli, V. & Gualtieri, P., eds), pp. 211–220. Springer Science + Business Media, Dordrecht.

Reimer, P. J., Baillie, M. G. L., Bard, E., Bayliss, A., Beck, J. W., Blackwell, P. G., Bronk Ramsey, C., Buck, C. E., Burr, G. S., Edwards, R. L., Friedrich, M., Groots, P. M., Guilderson, T. P., Hajdas, I., Heaton, T. J., Hogg, A. G., Hughen, K. A., Kaiser, K. F., Kromer, B., McCormac, F. G., Manning, S. W., Reimer, R. W., Richards, D. A., Southon, J. R., Talamo, S., Turney, C. S. M., van der Plicht, J. & Weyhenmeyer, C. E. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal BP. Radiocarbon, 51, 1111–1150.

Renberg, I. & Wik, M. 1985. Soot particle counting in recent lake sediments: an indirect counting method. Ecological Bulletins, 37, 53–57.

Rose, N. L. 1990. A method for the selective removal of inorganic ash particles from lake sediments. Journal of Paleolimnology, 4, 61–68.

Rose, N. L., Harlock, S., Appleby, P. G. & Battarbee, R. W. 1995. The dating of recent lake sediments in the United Kingdom and Ireland using spheroidal carbonaceous particle concentration profiles. Holocene, 5, 328–335.

Sayer, C. D. 2001. Problems with the application of diatom-total phosphorus transfer functions: examples from a shallow English lake. Freshwater Biology, 46, 743–757.

Søndergaard, M., Jeppesen, E. & Jensen, J. P. 2005. Water Framework Directive: ecological classification of Danish lakes. Journal of Applied Ecology, 42, 616–629.

Ter Braak, C. J. F. & Juggins, S. 1993. Weighted averaging partial least squares regression (WA-PLS): an improved method for reconstructing environmental variables from species assemblages. Hydrobiologia, 269/270, 485–502.

Veski, S., Koppel, K. & Poska, A. 2005. Integrated palaeo­ecological and historical data in the service of fine-resolution land use and ecological change assessment during the last 1000 years in Rõuge, S Estonia. Journal of Biogeography, 32, 1473–1488.

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