NEUSIEDLERSEE

A bird-eye view from the north

Photo.
Photo: L. Beckel




A. LOCATION

  • Burgenland, Austria; and Sopron, Hungary.
  • 47:38-47:57N, 16:41-16:52E; 115.4 m above sea level.






B. DESCRIPTION

    Neusiedlersee, the lake with the largest surface area in Austria (320 km2), is situated on the Austrian-Hungarian border with its southernmost part and its outflow in Hungary. Thick stands of Phragmites communis occupy the littoral zone of the lake which account for nearly 170 km2 swamp area (largest marsh area of Central Europe). The lake is characterized by its shallowness and high turbidity, caused by the erosion of silty bottom material. The lake water has a mean conductivity (S) of 1,800 (under ice cover it can increase up to 3,000) with an average ionic content of: Na+:Mg2+:Ca2+:K+ = 51:39:7:3 and HCO3-:SO42-:Cl- = 24:10:18.
    The lake occupies a tectonic depression which came into existence only some 13,000 years B. P. at the end of the Pleistocene. The lake has been extremely astatic throughout its history with more than one hundred times of desiccation and high water with the lake area almost twice its present surface. Since the last desiccation in 1868, extensive pure growth of P. communis have expanded mainly along its western and southern shores constituting nearly 99% of the emergent macrophytes vegetation.
    At present the lake is threatened with eutrophication problems caused mainly by tourism and agriculture. During the past two decades nutrient levels in the lake increased steadily resulting in successive algal blooms. Since 1976 the bloom species was Microcystis pulverea. Other man-made impacts include the artificial regulation of lake water level, hunting and poaching, introduction of exotic species and reclamation of reed areas for agriculture and tourism.
    Neusiedlersee was the site of an IBP project during 1967-1972 and the succeeding IHD and MAB programs. In 1978 the Austrian part and in 1979 the Hungarian part of the lake was declared as a biosphere reserve, thus establishing the first international biosphere reserve. An up-to-date account of the limnology of the lake is given by Loffler (1979)(Q, 1).


C. PHYSICAL DIMENSIONS (Q, 1)

    Surface area [km2] 320
    Volume [km3] 0.25
    Maximum depth [m] 1.8
    Mean depth [m] 0.8
    Water level Regulated
    Residence time [yr] 3-4
    Catchment area [km2] 1,300


D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL (Q)

  • Sketch map: Fig. EUR-02-02.
  • Bathymetric map: Fig. EUR-02-01.
  • Names of main islands: Small reed islands.
  • Number of outflowing rivers and channels (name): 1 (Einser Canal).

D2 CLIMATIC (Q)

  • Climatic data near the lake, 1951-1983

    Mean temp. [deg C]
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    -1.5 0.4 4.4 10.5 14.6 18.5 20.0 19.4 15.9 10.6 5.3 0.7 9.9*1
    Precipitation [mm]
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    34 33 42 54 59 80 69 65 40 48 51 42 617*2
    *1 1951-1970. *2 1967-1974.
  • Number of hours of bright sunshine (1981-1983): 1,893 hr yr-1.
  • Solar radiation (May-October, 1982 and 1983)*: 15.8 MJ m-2 day-1.

    Fig. EUR-02-01
    Bathymetric map (2).


    Fig. EUR-02-02
    Sketch map of surrounding areas (Q).


  • Water temperature [deg C]
    Breitenbrunn

    Breitenbrunn
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    2.7 1.6 5.8 11.2 17.1 19.6 23.4 20.7 16.1 11.2 3.8 1.9
    Illmits
    2.7 1.3 5.6 11.8 16.9 19.6 22.7 21.1 16.5 10.9 4.1 1.4
  • Freezing period: Late December-early March (54 days).
  • Mixing type: Polymictic.


E. LAKE WATER QUALITY (Q)

E2 pH

    Station 1, 1977
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    8.6 - 8.7 8.6 8.8 - 8.9 8.7 8.7 8.8 8.5 -
    Station 3, 1977
    8.7 - 8.7 8.7 8.8 - 8.9 8.8 8.9 8.8 8.7 -
    Station 17, 1977
    8.6 - 8.6 8.5 8.6 - 8.8 8.7 8.9 8.6 8.7 -

E3 SS [mg l-1]

    Station 1, 1977
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    2.3 - 7.5 46.1 - - 83.5 66.1 57.2 58.6 24.1 -
    Station 3, 1977
    13.3 - 30.0 35.3 57.4 - 132.2 48.5 134.5 171.3 39.4 -
    Station 17, 1977
    5.2 - 20.6 13.2 107.0 - 42.1 20.9 39.5 28.1 11.6 -

E4 DO [mg l-1]

    Bay, Neusiedl, 1968-1972
    Depth [m] Jan Feb Mar*1 Apr May*1 Jun Jul*2 Aug*2 Sep*2 Oct*3 Nov*3 Dec
    - - 15.8 - 10.8 - 9.4 9.5 - 6.7 10.9 -
    *1 1972. *2 1971. *3 1968.
    Centre, Neusiedl, 1968-1972
    - - 15.7 - 10.7 - - 9.3 - - - -
    Reed, Neusiedl, 1968-1972
    - - - - - - - - 4.9 4.5 5.63 -

E5 COD [mg l-1]

    No information.

E6 CHLOROPHYLL CONCENTRATION [micro g l-1]

    Station 1, 1977
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    12.0 19.7 24.5 15.3 - - 8.7 7.6 - 5.5 1.1 -
    Station 3, 1977
    14.2 24.0 22.3 13.1 7.5 - 14.2 6.6 - 9.8 7.6 -
    Station 17, 1977
    19.1 - 13.8 6.6 12.2 - 10.9 2.2 - - - -

E7 NITROGEN CONCENTRATION

  • NO3-N [mg l-1]

      • Station 1, 1977
      Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
      0.255 - 0.503 0.063 0.094 - 0.228 0.067 0.050 0.029 - -
      Station 3, 1977
      0.149 - 0.522 0.064 0.056 - 0.134 0.083 0.061 0.094 - -
      Station 17, 1977
      0.105 - 0.495 0.061 0.065 - 0.275 0.097 0.059 0.120 - -
  • NH4-N [mg l-1]

      • Station 1, 1977
      Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
      - - - - 0.033 - - 0.021 0.027 0.014 0.020 -
      Station 3, 1977
      - - - - 0.033 - - 0.019 0.067 0.021 0.022 -
      Station 17, 1977
      - - - - 0.035 - - 0.025 0.042 0.118 0.016 -

E8 PHOSPHORUS CONCENTRATION

  • Total-P [mg l-1]

    Station 1, 1977
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0.106 - 0.126 0.113 - - 0.122 0.075 0.120 0.069 0.081 -
    Station 3, 1977
    0.097 - 0.154 0.138 0.101 - 0.180 0.047 0.128 0.151 0.055 -
    Station 17, 1977
    0.134 - 0.141 0.155 0.323 - 0.339 0.130 0.060 0.196 0.281 -

E10 PAST TRENDS

    No information.


F. BIOLOGICAL FEATURES (Q)

F1 FLORA
  • Emerged macrophytes
    Phragmites australis (98%), Typha latifolia, Carex reparia.
  • Floating macrophytes
    Lemna trisulca (reed belt), Utricularia vulgaris (reed belt).
  • Submerged macrophytes: Myriophyllum spicatum Potamogeton pectinatus.
  • Phytoplankton
    Microcystis pulverea, Monoraphidium contortum, Cyclotella meneghiniana.

F2 FAUNA

  • Zooplankton
    Arctodiaptomus sponosus, Keratella quadrata, Diphanosoma brachyurum, Leptodora kindti.
  • Benthos: Tanypus punctipennis, Procladius sp.
  • Fish
    Blicca bjorkna, Gymnocephalus cernua, Pelecus cultratus, Anguilla anguilla*, Stizostedion lucioperca*, Ctenopharyngodon idella*, Cyprinus carpio*. * Economically important.

F3 PRIMARY PRODUCTION RATE [g C m-2 yr-1]

    Neusiedl Gross production
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.total
    11.4 9.8 102.3 56.5 85.1 188.9 180 188 218 53.4 9.1 30.3 86

F4 BIOMASS

    No information.

F5 FISHERY PRODUCTS

  • Annual fish catch [metric tons]
    1985: 150.
  • Fishery products other than fish: None.

F6 PAST TRENDS:

    No information.

F7 NOTES ON THE REMARKABLE CHANGES OF BIOTA IN THE LAKE IN RECENT YEARS

  • Macrophytes
    Submerged vegetation (Myriophyllum spicatum, Potamogeton pectinatus) was reduced.
  • Phytoplankton
    Monoraphidium (Ankistrodesmus falcatus) dominated in the 1950's, thereafter decreased and reappeared in 1972. Then Oocystis lacustris, a new entry to the lake, appeared. Cyclotella cornuta became prevalent and Botryococcus braunii formed frequent blooms. Since 1976 frequent blooms of Microcystis pulverea have taken place.
  • Zooplankton
    Moina rectirostris disappeared. Zooplankton increased and was dominated by rotifers in winter and spring. Leptodora kindti appeared in 1977.
  • Fish: Pelecus cultratus increased since mid 1970's.


G. SOCIO-ECONOMIC CONDITIONS (8, 1)

G1 LAND USE IN THE CATCHMENT AREA

    Area [km2] [%]
    - Natural landscape
    Woody vegetation 228.0 16.2
    Herbaceous vegetation 148.7 10.6
    Swamp 170 12.1
    Others 343.3 24.4
    - Agricultural land
    Crop field 186.7 13.3
    Pasture land 173.4 12.3
    Vine yard 156.9 11.2
    - Total 1,407 100
  • Levels of fertilizer application on crop fields: Heavy.
  • Trends of change in land use in recent years
    Area covered by vineyards increased during the 1970's.

G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE

    No information.

G3 POPULATION IN THE CATCHMENT AREA

    No information.


H. LAKE UTILIZATION (8, 1 )

H1 LAKE UTILIZATION
  • Sightseeing and tourism (no. of visitors (overnight stay) in 1980: 2,000,000), recreation (sport-fishing, yachting) and fisheries.

H2 THE LAKE AS WATER RESOURCE:

    No information.


I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS (Q)

I1 ENHANCED SILTATION
  • Extent of damage: Serious.

I2 TOXIC CONTAMINATION

  • Present status: No information.

I3 EUTROPHICATION

  • Nuisance caused by eutrophication
    Unusual algal bloom (Microcystis pulverea).
  • Nitrogen and phosphorus loadings to the lake [t yr-1]
    1984

      • Sources Industrial Domestic Agricultural Natural Total
      T-P - 54 72 18 144

I4 ACIDIFICATION: No information.

J. WASTEWATER TREATMENTS (Q)

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

    d) Measurable pollution with limited wastewater treatment.

J3 SANITARY FACILITIES AND SEWERAGE

  • Percentage of municipal population in the catchment area provided with adequate sanitary facilities (on-site treatment systems) or public sewerage: 100%.
  • Percentage of rural population with adequate sanitary facilities (on-site treatment systems): 100%.
  • Municipal wastewater treatment systems: 25%.


K. IMPROVEMENT WORKS IN THE LAKE

    No information.


L. DEVELOPMENT PLANS

    No information.


M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS (Q)

M1 NATIONAL AND LOCAL LAWS CONCERNED:

    No information.

M2 INSTITUTIONAL MEASURES:

    No information.

M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES

  1. Department of Limnology, Institute of Zoology, University of Vienna
  2. Biological Station, Illmitz


N. SOURCES OF DATA

  1. Questionnaire filled by Prof. H. Loffler, Zoologisches Institut, Universitat Wien, Austria.
  2. Loffler, H. (ed.)(1979) Neusiedlersee-Limnology of a Shallow Lake in Central Europe. Dr. W. Junk Publisher, The Hague.
  3. Atlas, AN 6014.