LAKE MEMPHREMAGOG

A view on the lake


Photo: J.Kalff  
 

A. LOCATION

  • Quebec, Canada; and Vermont, USA.
  • 44:5-45:5N, 72:0-72:7W; 208 m above sea level.
 

B. DESCRIPTION

Lake Memphremagog is a long (40 km) but narrow (1-3 km) lake, located 130 km to the east of Montreal, Quebec. It is a transboundary lake, receiving 71% of its stream inflow from the Vermont, USA, portion of its catchment, but with 75% of the lake surface area in Quebec, Canada. It is a lake of exceptional, rugged beauty; set in a diverse landscape, hilly and mountainous to the west, but with pastoral, rolling farmland to the east.

The drainage basin of Lake Memphremagog is situated in the physiographic region of the Piedmont. Its early geologic history is tied to the uplift and folding of the Appalachian Mountain chain. The present lake basin was formed about 11,000 B. P. by glacial gouging of a preexisting valley during the final retreat of the Wisconsin glaciation. Following the termination of the Champlain Sea phase, the present lake was formed about 9,500 B. P.

The lake has three distinct basins, a deep Central, and shallower North and South basins. 70% of the lake's watershed is drained by three rivers which enter the lake at the extreme south end and provide the primary input of nutrients into the lake. This has resulted in a distinct nutrient gradient within the lake - the southern end is mesotrophic, while the Central and North basins remain oligotrophic.

The first known settlements were established by the St. Francis Indian community on what they called Lake "Mem-plow-bouque" (large, beautiful expanse of water). The first European settlements were founded in 1793 at Ducansborough (now Newport, Vermont) and in 1794 at Gibraltar Point (now Bolton, Quebec). The Canadian side was largely settled by United Empire Loyalists (settlers who left America after the revolution because they wanted to remain under the British Flag). The lake was popular as a recreation and vacation area in the mid-to-late 1800's, but tourism dropped off sharply after the turn of the century and the area was not subjected to the intensive development pressures and related problems that have affected other river basins in the northeastern United States or southern Quebec. These historical trends are changing as the 1980's brought a new tourism boom and a steady wave of related development to both the American and Canadian portions of the lake basin. The problems associated with increased development have, for the present, been offset by a continuing reduction in crop growing and increased forest regrowth, as well as the installation of tertiary sewage treatment at Newport in 1983 (1, 2, 3).
 

C. PHYSICAL DIMENSIONS (1, 2)

     
    Basin North Central South Total
    Surface area [km2] - - - 102
    Volume [km3] - - - 1.7
    Maximum depth [m] 33 (2) 107 12 107
    Mean depth [m] 13 55 8 15.5
    Water level - - - Regulated
    Normal range of annual water level fluctuation [m] - - - 0.5
    Length of shoreline [km] - - - 121
    Residence time [yr] - - - 1.7
    Catchment area [km2] - - - 1,764
     
 

D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL

  • Bathymetric map: Fig. NAM-48-01.
  • Names of main islands

    • Trois Soeurs, Lords, Molson, Longue, Ronde, Province and Whetstone.
  • Number of outflowing rivers and channels (name): 1 (Magog R.).

D2 CLIMATIC

  • Climatic data at Sherbrooke*, 1987 (6)
     
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    Mean temp. [deg C] -11 -13 -2 7 11 18 19 16 13 6 -1 -6 4
    Precipitation [mm] 58 22 54 41 99 124 85 58 93 117 112 62 925
    * 23 km from the outflow.
  • Number of hours of bright sunshine: 1,895 hr yr-1.
  • Solar radiation (Montreal Jean Brebeuf*)[MJ m-2 day-1]
     
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    5.30 8.80 12.51 15.87 9.07 20.25 20.96 17.23 13.45 8.04 4.61 3.92 12.5
    * 100 km from the outflow.
    Fig. NAM-48-01
    Bathymetric map [30 ft=9.14 m](Q).
 
  • Water temperature [deg C](4)
     
    South basin, 1985 
    Depth [m] Jan Feb Mar Apr May*1 Jun*2 Jul*3 Aug*4 Sep Oct Nov Dec
    S*5 - - - - 9.5 14.4 22.7 22.3 - - - -
    1 - - - - 9.3 14.4 21.1 22.6 - - - -
    2 - - - - 9.0 14.2 20.6 22.8 - - - -
    3 - - - - 8.8 14.2 20.3 23.1 - - - -
    4 - - - - 8.7 14.2 20.2 23.5 - - - -
    5 - - - - 8.5 14.1 20.1 23.9 - - - -
    6 - - - - 8.5 14.1 19.9 24.1 - - - -
    7 - - - - 8.4 14.1 16.2 23.9 - - - -
    8 - - - - 5.2 13.7 15.6 23.9 - - - -
    9 - - - - 5.1 11.2 - - - - - -
    *1 13 May. *2 12 June. *3 17 July. *4 28 August. *5 Surface.
     
    North basin, 1985 
    Depth [m] Jan Feb Mar Apr May*1 Jun*2 Jul*3 Aug*4 Sep Oct Nov Dec
    S - - - - 4.9 13.2 24.1 22.1 - - - -
    1 - - - - 4.9 13.1 23.8 22.1 - - - -
    2 - - - - 4.8 12.4 22.1 22.1 - - - -
    3 - - - - 4.8 12.2 21.3 22.1 - - - -
    4 - - - - 4.8 12.2 21.0 22.1 - - - -
    5 - - - - 4.8 11.3 20.3 22.1 - - - -
    6 - - - - - 10.0 19.8 22.1 - - - -
    10 - - - - - 6.6 16.4 22.1 - - - -
    15 - - - - - - - 16.1 - - - -
    *1 14 May. *2 28 May. *3 17 July. *4 28 August.
     
    Central basin, 1985 
    Depth [m] Jan Feb Mar Apr May*1 Jun*2 Jul*3 Aug*4 Sep Oct Nov Dec
    S - - - - 8.4 13.8 23.5 20.6 - - - -
    1 - - - - 8.3 13.8 21.4 20.8 - - - -
    3 - - - - 8.3 13.8 20.2 20.8 - - - -
    5 - - - - 8.0 13.7 19.2 20.8 - - - -
    7 - - - - 7.5 13.6 18.3 20.5 - - - -
    9 - - - - 6.8 12.9 17.1 20.4 - - - -
    11 - - - - 6.5 10.9 15.6 19.9 - - - -
    13 - - - - 6.2 9.4 13.3 17.8 - - - -
    15 - - - - 6.2 9.1 10.5 12.4 - - - -
    17 - - - - 6.1 8.4 8.3 9.1 - - - -
    19 - - - - 6.0 6.8 7.2 8.8 - - - -
    *1 23 May. *2 12 June. *3 17 July. *4 28 August.
  • Freezing period

    • South basin: Early December-middle April.
    North and central basin: Middle December-middle April.
  • Mixing type

    • South basin: Polymictic.
    North and central basin: Dimictic.
  • Notes on water mixing and thermocline formation

    • Thermally stratified in the Central and North basins, late May-October, with thermocline at 9-11 m depth.
 

E. LAKE WATER QUALITY

E1 TRANSPARENCY [m](4)

     
    North basin, 1987 
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    - - - - 6 5 5.3 4.8 5.8 - - -
     
     
    Central basin, 1987 
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    - - - - - 3.9 4.5 4.3 3.5 5.7 - -
     
     
    South basin, 1987 
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    - - - - 2.9 3.6 3.6 - 4.8 - - -
     

E2 pH

     
    Central basin, 1987 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    S* - - - - - - - 8.3 - - - -
    * Surfaca.
     
    Newport Bay, 1988 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    S - - - - - 6.7 - 7.1 - - - -
     

E4 DO [mg l-1](18)

     
    Central Basin, 1985 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    1 - - - - 12.5 10.8 9.5 9.3 8.8 - - -
    3 - - - - 12.6 10.8 9.7 9.3 8.9 - - -
    5 - - - - 12.6 10.8 9.9 9.4 8.9 - - -
    7 - - - - 12.7 10.8 10.0 9.5 8.8 - - -
    9 - - - - 12.6 10.8 9.7 9.5 8.7 - - -
    11 - - - - 12.5 10.8 9.5 9.5 8.0 - - -
    13 - - - - 12.4 10.8 9.1 8.8 7.3 - - -
    15 - - - - 12.3 10.8 9.1 8.2 7.5 - - -
    17 - - - - 12.3 10.9 9.5 7.8 8.4 - - -
    19 - - - - 12.3 10.9 9.7 8.1 8.7 - - -
    21 - - - - 12.3 11 10.2 8.8 9.3 - - -
     

E6 CHLOROPHYLL CONCENTRATION [micro l-1](4)

     
    North Basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - 3.0 4.2 2.5 2.6 3.3 - - -
    *1 Monthly mean. *2 Integrated.
     
    Central Basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - 4.0 3.9 2.1 3.6 2.9 - - -
     
     
    South Basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - 4.7 6.0 4.2 3.6 2.3 - - -
     

E7 NITROGEN CONCENTRATION (4)

  • Total-N [mg l-1]
     
    North basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - 0.60 0.35 0.28 0.30 0.23 - - -
    *1 Monthly mean. *2 Integrated.
     
    Central basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - 0.65 0.42 0.31 0.23 0.39 - - -
     
     
    South basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - 0.46 0.42 0.36 0.29 0.27 - - -
     

E8 PHOSPHORUS CONCENTRATION (4)

  • Total-P [mg l-1]
     
    North basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - .013 .013 .011 .010 .009 - - -
    *1 Monthly mean. *2 Integrated.
     
    Central basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - .017 .013 .012 .011 .011 - - -
     
     
    South basin, 1987*1 
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    5*2 - - - - .016 .016 .016 .015 .014 - - -
     

E10 PAST TRENDS: Fig. NAM-48-02 and 03.

    Fig. NAM-48-02
    Mean summer concentration of chlorophyll a, 1972-1986 [micro l-1].
 
    Fig. NAM-48-03
    Mean summer concentration of Total-P, 1972-1986 [micro l-1].
 
 

F. BIOLOGICAL FEATURES

All stations combined, 1973-1987

F1 FLORA

  • Submerged macrophytes (7)

    • Cabomba caroliniana, Elodea canadensis, E. septangular, Heteranthera dubia, Isoetes sp., Myriophyllum spicatum, Najas sp., Potamogeton richardsonii, P.
    praelongus, Vallisneria americana, Nitella sp.
  • Phytoplankton (14)

    • South basin: Diatoma tenue var. elongatum, Oscillatoria redekei, Ceratium hirundinella, Rhodomonas minuta, Melosira italica, Cryptomonas reflexa, Stephanodiscus astraea, S. nantzschii, Asterionella formosa, Fragilaria crotonensis, Uroglena volvox, Anabaena flos-aqae, Gleococcus schraeteri, Coelosphaerium naegelianum.
    North basin: Diatoma tenue, Oscillatoria redekei, Fragilaria crotonensis, Rhizosolenia eriensis, R. minuta, Botryococcus braunii, Cyclotella bodanika, C. hirundinella, Synedra ulna var. danica, Chrysochromulina parva, Gleococcus schroeteria, Coelosphaerium naegelianum.

F2 FAUNA

  • Zooplankton (12, 16, 17)

    • Cyclops bicuspidatus thomasi, C. vernalis, Mesocyclops edax, Diaptomus sicilis, D. minutus, Tropocyclops prasinus mexicanus, Epischura lacustris, Senecella calanoides, Daphnia galeata, Bosmina longirostris, B. coregoni, Chydorus sphaericus, Holopedium gibberum, Ceriodaphnia quadrangula, Diaphanosoma leuchtenbergianum, Keratella sp., Monostyla sp., Polyarthra sp.
  • Benthos (8, 12)

    • Chironomus anthracinus, Chaoborus punctipennis, Tanytarsus spp., Procladius spp., Phaenospectra sp., Microspectra sp., Pontoporeia hoyi, Amnicola sphaerium, Fossaria, Helisoma.
  • Fish (9)

    • Hybognathus nuchalis, Notemigonus crysoleucas, Notropis volucellus, Pimephales notatus, Etheostoma nigrum, Perca flavescens, Fundulus diaphanus, Lepomis gibbosus, Micropterus dolomieu, Semotilus corporalis, Catostomus commersoni, Osmerus mordax.
  • Supplementary notes on the biota (8, 9)

    • The nutrient gradient along the axis of the lake influences the abundance and distribution of organisms. Biomass of fish species is about three times greater in the more productive southern end. Phytoplankton and benthos biomass and production too are greater in the south.

F3 PRIMARY PRODUCTION RATE (10)

  • Phytoplankton

    • Net C14 Production rate [g C m-2 day-1]
     
    North basin, November 1972-October 1973 
    1973 1972 Ann.
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec total
    0.1 0 0.1 0.3 0.8 0.9 0.7 0.7 1.0 0.5 0.3 0.2 175*
     
     
    Central basin, November 1972-October 1973 
    1973 1972 Ann.
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec total
    - - - - 0.6 1.0 0.7 1.0 - - - - -
     
     
    South basin, November 1972-October 1973 
    1973 1972 Ann.
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec total
    0.1 0.1 0.3 0.7 0.7 0.7 1.3 1.1 1.5 0.7 0.2 0.1 219*
    * 1972-1973.

F4 BIOMASS (9)

  • Benthos [g (dry wt.) m-2]

    • 1972-1973 South basin: 3.30 òÂ0.25.
    North basin: 1.19 òÂ0.06.

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

    None.
 

G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA (1, 2)

     
    1981 
    Area [km2] [%]
    Natural landscape 
    - Woody vegetation 1,300 74
    - Herbaceous vegetation 88 5
    - Swamp 36 2
    Agricultural land
    - Crop field 240 14
    Residential area 80 5
    Total 1,744 100
     
  • Types of important forest vegetation: Maple, beech, birch, spruce, fir.
  • Types of important herbaceous vegetation: Abandoned pasture, hay.
  • Main kinds of crops and/or cropping systems: Hay, maize.
  • Levels of fertilizer application on crop fields

    • Light (manure application).
  • Trends of change in land use in recent years (2)

    • Historically, economy based on natural resources. Now manufacturing is playing a more significant role. 37% decline in natural resource industries (agriculture, forestry) from 1960 to 1970. In the 1980's, 10% of woodland harvested annually.

G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE (2)

     
    1974 
    U.S. portion of the catchment area (Orleans County) only. 
    Gross product during the year (= US$1.00) Percentage of persons engaged No. of establishments Main products or major industries
    Primary industry 24 mill. 16 666
    - Crop production Corn, hay
    - Animal husbandry Dairy products
    - Fisheries
    Secondary industry
    - Manufacturing & construction N.A. 32 27 Machinery, clothing Service, transport, etc.
    Tertiary industry N.A. 40
    (Unemployed) 12
     
  • Numbers of domestic animals in the catchment area

    • Cattle 25,000, others unknown.

G3 POPULATION IN THE CATCHMENT AREA (2)

     
    1975 
    Population* density [km-2] Population (population) Main cities
    Rural 19,702
    Total 19,702 11.2 Newport, Derby
    * Included - 18,702 in U.S. and 1,000 in Canada.
  • Supplementary notes (1)

    • Seasonal population is +20,000, and rapidly growing. More than 1,500 vacation cottages line the shores of the lake.
 

H. LAKE UTILIZATION

H1 LAKE UTILIZATION

    Source of water, sightseeing and tourism (no. of visitors in 1975: 20,000) and recreation (swimming, sport-fishing, yachting).

H2 THE LAKE AS WATER RESOURCE (2)

     
    1974 
    Use rate [m3 sec-1]
    Domestic 1
    Industrial 34
     
 

I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS

I1 ENHANCED SILTATION

  • Extent of damage: Not serious.
  • Supplementary notes

    • Excessive erosion and sedimentation on cropland on steep slopes-on Vermont rivers. Streambank erosion due to livestock and soil erosion due to poor logging practices. Offset by gradual reduction in cropland and increases in pasture and forest.

I2 TOXIC CONTAMINATION

  • Present status: Detected but not serious.
  • Main contaminants, their concentration and sources
     
    North basin, 1988 
    Name of contaminants Concentration [ppm] in bottom mud*
    Zn 198
    Mn 533
    Ni 109
    Cu 45
    Pb 117
    * Dry weight basis.
  • Supplementary notes (11)

    • Metal levels not highly variable throughout the lake.

I3 EUTROPHICATION

  • Nitrogen and phosphorus loadings to the lake [t yr-1](13)
     
    1972, 1987 
    Sources Domestic 1987 River loading 1972 Natural recip. 1972 Total
    T-P 1 21 7 29
     
  • Supplementary notes (13)

    • Eutrophication has only been a problem in the extreme south end of the lake, while north and central basins are oligotrophic. However, a new sewage treatment system that went into operation in 1983 reduced the T-P loadings (from the town of Newport) from 20 t yr-1 to 

I4 ACIDIFICATION

  • Extent of damage: None.
 

J. WASTEWATER TREATMENTS

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

    (c) Limited pollution with 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): Unknown.
  • Municipal wastewater treatment systems

    • No. of tertiary treatment systems: 3 (P removal).
    No. of secondary treatment systems: 3.
  • Industrial wastewater treatment systems

    • No. of industrial wastewater treatment systems: 2.
 

K. IMPROVEMENT WORKS IN THE LAKE (Q)

    None.
 

L. DEVELOPMENT PLANS (Q)

Increasing recreational development and condominium construction.

M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS

M1 NATIONAL AND LOCAL LAWS CONCERNED

  • Names of the laws (the year of legislation)
    1. The level at which Lake Memphremagog should be maintained. Dam on outflow (1935).
  • Responsible authorities
    1. Environment Canada, U.S. Dept. of the Army/Corps of Engineers, Quebec
    2. Dept. of the Environment
  • Main items of control
    1. Lake level

M2 INSTITUTIONAL MEASURES

Memphremagog Conservation Inc., Quebec (employs students in clean-up work and public education).

M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES

  1. Limnology Research Centre, McGill University, Montreal, Quebec
 

N. SOURCES OF DATA

  1. Questionnaire filled by Dr. J. Kalff, Limnology Research Centre, McGill University, Montreal, Canada.
  2. Memphremagog Conservation Inc. (1982) Environmental Land Use Guide of the Lake Memphremagog Watershed.
  3. New England River Basins Commission (1981) Lake Memphremagog-St. Francis River Basin Overview.
  4. Carlson, R. E., Kalff, J. & Leggett, W. C. (1979) The phosphorus and nitrogen budgets of Lake Memphremagog; with a predictive model of its nutrient content following sewage removal.
  5. Limnology Research Centre (1972-1988) Lake Memphremagog Data Collection.

    6. McGill University, Montreal, Quebec.
  6. Rasmussen, J. Personal communication.
  7. Environment Canada (1987) Meteorological reports.
  8. ) Canadian Climate Normals, 1951-1980. Environment Canada, Atmospheric Environment Service.
  9. Downing, J. A. & Anderson, M. R. (1985) Estimating the standing biomass of aquatic macrophytes. Can. J. Fish. Aquat. Sci., 42(12): 1860-1869.
  10. Dermott, R. M., Kalff, J., Leggett, W. C. & Spence, J. (1977) Production of Chironomus, Procladius and Chaoborus at different levels of phytoplankton biomass in Lake Memphremagog, Quebec-Vermont. Can. J. Fish Aquat. Sci., 34(11): 2001-2007.
  11. Gascon, D. & Leggett, W. C. (1977) Distribution, abundance and resource utilization of littoral zone fishes in response to a nutrient/production gradient in Lake Memphremagog. J. Fish. Res. Bd., 34: 1105-1117.
  12. Ross, P. E. & Kalff, J. (1975) Phytoplankton production in Lake Memphremagog, Quebec (Canada) - Vermont (USA). Verh. Int. Ver. Limn., 19: 760-769.
  13. Rowan, D., McGill Univ. Personal communication.
  14. Morse, J. W. & Flanders, P. H. (1971) Primary Productivity Study of Three Vermont Lakes. State of Vermont Agency of Conservation.
  15. Kalff, J. & Lawson, A. (1988) The Capacity of Lake Memphremagog for Further Development. Limnology Research Centre, McGill University.
  16. Watson, S. (1979) Phytoplankton dynamics in Lake Memphremagog and their relationship to trophic level. M. Sc. Thesis, McGill University, Montreal.
  17. Chambers, P. & Kalff, J. (1985) Depth distribution and biomass of submerged aquatic macrophyte communities in relation to Secchi depth. Can. J. Fish. Aquat. Sci., 42: 701-709.
  18. Sarafian, V. (1984) Life cycles, biomass and production of copepods in Lake Memphremagog. M. Sc. Thesis, Concordia University, Montreal.
  19. Shoenert, R. A. & Peters, R. H. Cladoceran abundance along the trophic gradient of Lake Memphremagog. Internal report. McGill University, Montreal.
  20. Marshall, T. Personal communication.