ATTERSEE

A bird-eye view of the lake

Photo.
Photo: L. Beckel


A. LOCATION

  • Upper Austria, Austria.
  • 47:52N, 13:32E; 469.2 m above sea level.


B. DESCRIPTION

    With a length of 19.5 km and a maximum width of 3.3 km Attersee is the largest lake within the Austrian borders. According to its glacial origin, most of the western and northern part of the lake is characterized by moraine material. The eastern and southern area consists of flysch and limestone respectively. Situated in the prealpine region of Upper Austria, the lake and its immediate area is primarily used for agriculture and touristic recreation. Attersee is the last link in a chain of lakes within the catchment area. Fifty-five percent of the surface inflow of the lake comes from Mondsee, via a 2 km-long river. This tributary contributes up to 60% of the total annual phosphorus load to Attersee. However, the lake is still to be classified as oligotrophic. The construction of a system of sewers collecting domestic sewage was finished in 1980. This measure was taken in order to prevent eutrophication due to continuously increasing tourist activities.

C. PHYSICAL DIMENSIONS (Q)

    Surface area [km2] 46
    Volume [km3] 3.945
    Maximum depth [m] 170.6
    Mean depth [m] 84.2
    Length of shoreline [km] ca. 50
    Residence time [yr] 7
    Catchment area [km2] 464

D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL (Q)
  • Number of outflowing rivers and channels (name): 1 (Ager R.).
D2 CLIMATIC (Q)
  • Climatic data at Weyregg, 1976

    Mean temp. [deg C]
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    1.6 -0.3 1.1 7.9 12.4 16.4 18.3 14.4 11.8 8.9 4.2 -2.1 7.9
    Precipitation [mm]
    150 3.4 14 55.8 157.1 75.4 192.7 189.6 91.6 44.2 86.7 50.6 1111.2
  • Number of hours of bright sunshine: 1,651 hr yr-1.
  • Solar radiation: 242.3 MJ m-2 day-1.
  • Water temperature [deg C]
    Lake centre
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0* 3.4 4 - 4.6 12.3 18.8 22.8 18.3 14.4 - 9.3 -
    10 3.7 3.9 - 4.2 6.1 11.6 20.2 17.9 14.4 - 9.3 -
    20 3.9 4.0 - 4.1 5.8 6.0 6.8 6.5 7.5 - 6.5 -
    30 3.9 4.0 - 4.1 4.7 4.4 4.7 4.5 4.7 - 4.6 -
    40 3.9 4.0 - 4.0 4.3 4.2 4.4 4.2 4.3 - 4.3 -
    * Surface.
  • Freezing period: Rare.
  • Mixing type: Dimictic.

E. LAKE WATER QUALITY (Q)

E1 TRANSPARENCY [m] Weyregg, 1975-1978
    Depth [m] Min Max Ann.
    5 15 8-9
E2 pH Lake centre, 1979
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0 8 7.92 8.05 8.07 8.1 8.2 8.2 8.05 7.95 7.8 8.0 7.55
    50 - - 7.65 7.95 7.85 7.8 7.75 7.7 7.6 7.5 7.65 -
    100 7.75 7.7 7.95 7.85 7.8 - 7.75 7.6 7.6 7.4 7.65 7.45
    1975-1978: Epilimnion maximum 8.5 and hypolimnion 7.8-8.1.

E4 DO [mg l-1] Lake centre, 1975

    Depth [m] Jan-Feb Mar Apr May Jun Jul-Aug Sep-Oct Nov Dec
    0 11-11.5 12 12 12.5 11.5 11-11.5 9-10 10-11 * * 11-11.5.
    Depth [m] Jan-Feb Mar-Apr May Jun Jul Aug Sep-Oct Nov-Dec
    20 10-11 11.5-12 12 11 - 11.5 10-10.5 10-11
    Depth [m] Jan-Feb Mar-Apr May Jun Jul Aug Sep-Oct Nov-Dec
    50 9-10 11.5-12 12.2 11 - 11.5 10-10.5 9-10
    Depth [m] Jan-Feb Mar-Apr May-Jun Jul Aug Sep Oct Nov-Dec
    100 9-10 11-11.5 11-12 11 10.5 - 10 9-10
E6 CHLOROPHYLL CONCENTRATION [mg m-2] Unterach, 1975
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    * 23.5 21.5 22 22.4 40.8 50.9 40.7 30.9 40 49.9 56.8 72.6
    * Integrated, photic zone.
E7 NITROGEN CONCENTRATION > NO3-N [mg l-1]
    Lake centre, 1979
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0 0.360 0.402 0.292 0.460 0.427 0.346 0.416 0.428 0.256 0.398 0.379 0.539
    50 - - 0.270 0.535 0.525 0.562 0.484 0.530 0.487 0.538 0.572 -
    100 0.344 0.422 0.223 0.524 0.534 - 0.528 0.537 0.520 0.520 0.535 0.741
E8 PHOSPHORUS CONCENTRATION
  • Total-P, [micro g l-1]
    Lake centre, 1979
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0 5.6 5.3 5.7 3.5 7.5 10.0 11.0 6.5 4.5 - 7.5 6.5
    50 - - 4.8 6.0 12.0 6.0 7.5 6.0 3.5 6.5 4.5 -
    100 4.9 4.6 6.6 7.0 8.5 - 7.5 5.5 5.5 4.5 4.0 6.5

F. BIOLOGICAL FEATURES (Q)

F1 FLORA
  • Emerged macrophytes: Scirpus lacustris.
  • Submerged macrophytes
    Chara sp., Potamogeton trichoides, P. perfoliatus, Myriophyllum spicatum, Elodea sp.
  • Phytoplankton
    Cyanophyceae (Aphanotheca sp., Oscillatoria rubescens); Chrysophyceae (Dinobryon bavaricum, D. sociale, D. divergens); Diatom (Tabellaria fenestrata, Asterionella formosa, Fragilaria crotonensis, Cyclotella commensis, C. badanica); Chlorophyceae (Geminella minor); Cryptophyceae (Rhodomonas minuta).
F2 FAUNA
  • Zooplankton
    Daphnia cucullata, D. hyalina, Eubosmina longirostris, Bythirephes longimanus, Cyclops abyssorum, Mesocyclops leucartii, Mixodiaptomus laciniatus.
  • Benthos
    Ostracoda (Cytherissa lacustris, Limnocythere sanctipatricii); Turbellaria (Otemesostoma auditivum); Annelida (Limnodrilus sp., Peloscolex velutinus, Potamothrix hammoniensis, Rhynchelmis limosella).
  • Fish
    Salvelinus alpinus*, Coregonus spp.*, Esox lucius. * Economically important.
F3 PRIMARY PRODUCTION RATE [C mg m-2 hr-1]
    Unterach, 1975
    Net production
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    18.6-60.0 18.6 28.4 27.6 37.3 - 38.2 44.6 55.1 60.5 - 42.7
F4 BIOMASS:No information.
F5 FISHERY PRODUCTS:No information.
F6 PAST TRENDS:No information.

G. SOCIO-ECONOMIC CONDITIONS (Q)

G1 LAND USE IN THE CATCHMENT AREA
    Area [km2] [%]
    - Natural landscape
    Woody vegetation 1,113.9 44.0
    Lake & running water 488.6 19.3
    Others 192.4 7.6
    - Agricultural land
    Crop field 192.4 7.6
    Pasture land 415.2 16.4
    - Residential area 78.5 3.1
    - Others 50.6 2.0
    - Total 2,531.6 100.0
  • Levels of fertilizer application on crop fields
    Heavy (P2O5 71.3 kg ha-1 yr-1)
G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE
    No information.
G3 POPULATION IN THE CATCHMENT AREA 1970
    Population Population density [km-2] Major cities (population)
    Rural 13,479 73.7 None
    Total 13,479 73.7 (several villages)

H. LAKE UTILIZATION (Q)

H1 LAKE UTILIZATION
  • Sightseeing and tourism (no. of visitors in 1970: 727,328), recreation (swimming, sport-fishing, yachting).

H2 THE LAKE AS WATER RESOURCE:No information.

I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS (Q)

I1 ENHANCED SILTATION
  • Extent of damage: None.
I2 TOXIC CONTAMINATION
  • Present status: None.
I3 EUTROPHICATION
  • Nuisance caused by eutrophication: None.
  • Nitrogen and phosphorus loadings to the lake [kg yr-1]
    1978-1979
    Sources Total
    T-P 1978 11,075
    1979 13,780
  • Supplementary notes
    55% of phosphorus load by river Mondsee Ache, unknown seepage from tourism and agriculture.
I4 ACIDIFICATION
  • Extent of damage: No information.

J. WASTEWATER TREATMENTS (Q)

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA
    b) No sources of significant pollution.
J2 APPROXIMATE PERCENTAGE DISTRIBUTION OF NUTRIENT LOADS
    [%]
    - Non-point sources 40-45
    - Point sources
    Tributary Mondsee Ache 55-60
    - Total 100
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: 99%.
  • Percentage of rural population with adequate sanitary facilities (on-site
    treatment systems): 99%.
  • Municipal wastewater treatment systems: Ring channel.

K. IMPROVEMENT WORKS IN THE LAKE (Q)

K1 RESTORATION

  • Since 1976, sewage treatment plant (ring channel) discharging into outlet.

L. DEVELOPMENT PLANS

    No information.

N. SOURCES OF DATA

  1. Questionnaire filled by Prof. H. Loffler, Zoologisches Institut, Universitat Wien, Austria.