Skip to main content

Long-term Changes in Environmental Variables of Traunsee, an Oligotrophic Austrian Lake Impacted by the Salt Industry, and Two Reference Sites Hallstättersee and Attersee


Morphometric, hydrological and basic physico-chemicalcharacteristics of three deep Alpine lakes, Traunsee,Hallstättersee and Attersee as well as their long-termbahaviour are presented. The deep Alpine lakesHallstättersee and Traunsee have been influenced by saltmining and the traditional salt industry for over 100 years. Waste products from these activities, entering the lakes, have mainlyaffected the chemistry of these water bodies, especially bysubstantially increasing the chloride concentrations up to 170 mg L-1. As a consequence of the increased density, mixing conditions of the lakes were altered. The resulting incomplete mixing led to oxygen depletionin deeper layers. In addition, increased nutrientload from the catchment rised the trophic level in the 70s and 80sof the last century in turn, affecting the oxygen content in thehypolimnion. Finally a situation developed where the risk becamehigh for these lakes to become meromictic induced by humanactivity. In fact, Hallstättersee became facultativelymeromictic. This process was interrupted by increased chlorideinput of more than 30 mg L-1 due to accidental wash outfrom an upstream salt mine rendering Hallstätterseehomogenous in 1978 to 1980 resulting in complete over-turn. Conditions substantially improved in both lakes after miningpractices were altered and restoration measures againsteutrophication were initiated. Chloride and phosphorusconcentrations declined, while oxygen conditions substantiallyimproved in the following years. Conditions in Traunseesubstantially improved and chloride levels near the sedimentdecreased to less than 140 mg L-1. The third lakeconsidered here, Attersee, always remained in a near-naturalstate although some signs of increased nutrient levels becamevisible in the late 1970s. Chloride concentrations of around 3 mgL-1 in this lake can be considered as background levels.Attersee can now serve as a reference site for deep Alpine lakesbecause of its ultra-oligotrophic and pristine nature.

This is a preview of subscription content, access via your institution.


  • Dokulil, M. and Jagsch, A.: 1989, 'Some aspects of the impact of tourism on Mondsee, Austria', Symp. Biol. Hung. 38, 415–428.

    Google Scholar 

  • Dokulil, M. and Teubner, K.: 2002, 'Assessment of ecological integrity from environmental variables in an impacted oligotrophic, alpine lake: Whole lake approach using 3D-spatial heterogeneity', Water, Air, and Soil Pollut.: Focus 2(4), 165–180.

    Google Scholar 

  • EAWAG: 1974, Vorläufige Empfehlungen über die regelmäßige Untersuchung der schweizerischen Oberflächengewässer, Eidgen. Dept. des Inneren, Bern, 69 pp.

    Google Scholar 

  • Einsele, W.: 1962, Gutachten v. 24.5.1962 betreffend Ebenseer Solvay Werke. Einleitung von Betriebsabwässern und Feststoffen in den Traunsee.

  • ISO/TC 147: 1988, 'Water quality - Measurement of Biochemical Parameters-Spectrometric Determination of Chlorophyll-a', Int. Org. of Standardisation.

  • Jagsch, A.: 1982, 'Hallstättersee und Wolfgangsee', Limnol. Unters. Traunsee-Traum, Bericht 7, O.Ö. Landesreg., Linz, 114 pp.

    Google Scholar 

  • Jagsch, A. and Schwarz, K.: 1999, 'Zur fakultativen Meromixis des Hallstättersees', Tagungsbericht 1998 der Deutschen Gesellschaft f. Limnologie (DGL), Eigenverlag d. DGL, Tutzing, pp. 224–228.

    Google Scholar 

  • Neresheimer, E. and Ruttner, F.: 1927, Drittes Gutachten über die Eintleitung der Ammoniaksoda-fabrik (Solvay-Werke) in Ebensee in den Traunsee, 6 pp.

  • Nusch, E. A.: 1980, 'Comparison of different methods for chlorophyll and phaeopigment determinations', Arch. Hydrobiol., Beih. Ergebn. Limnol. 14, 14–36.

    Google Scholar 

  • Pechlaner, R. and Sossau, Ch.: 1982, Die Ergebnisse der 5-jährigen Studie, Limnologische Untersuchung Traunsee-Traun, Limnol. Unters. Traunsee-Traun, Bericht 13, O.Ö. Landesreg., Linz, 245 pp.

    Google Scholar 

  • Schwarz, K.: 1992, 'Schilfrückgang am Traunsee', Kataloge des O.Ö. Landesmuseums 54, 393–400.

    Google Scholar 

  • Schwarz, K. and Jagsch, A.: 1998, 'Die Seen Oberösterreichs', Gewässerschutzbericht 20, Amtd. O.Ö. Landesregierung, Linz, CD-Rom.

    Google Scholar 

  • Sossau, Ch.: 1982, Schichtungs-und Strömungsverhältnisse, Chlorid und Sauerstoff im Traunsee, Limnol. Unters. Traunsee-Traun, Bericht 9, O.Ö. Landesreg., Linz, 158 pp.

    Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to A. Jagsch.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Jagsch, A., Gassner, H. & Dokulil, M.T. Long-term Changes in Environmental Variables of Traunsee, an Oligotrophic Austrian Lake Impacted by the Salt Industry, and Two Reference Sites Hallstättersee and Attersee. Water, Air, & Soil Pollution: Focus 2, 9–20 (2002).

Download citation

  • Issue Date:

  • DOI:

  • chloride
  • meromixis
  • oxygen
  • phosphorus