1992

1993

1994

1995

1996

1997

1998

1999

2000

number of sites sampled

47

46

47

47

48

51

50

50

50

all submersed vegetation

68.1

78.3

93.6

97.9

89.6

98.0

84.0

92.0

78.0

coontail

Ceratophyllum demersum

66.0

73.9

87.2

91.5

85.4

90.2

84.0

86.0

70.0

Canadian waterweed

Elodea canadensis

-

19.6

61.7

78.7

43.8

54.9

62.0

64.0

64.0

curly pondweed

Potamogeton crispus

2.1

23.9

21.3

6.4

20.8

51.0

6.0

16.0

44.0

leafy/small pondweed

P. foliosus/P. pusillus

-

30.4

4.3

8.5

16.7

7.8

-

-

-

sago pondweed

P. pectinatus

23.4

52.2

40.4

10.6

39.6

39.2

10.0

38.0

24.0

all rooted floating leaf vegetation

46.8

39.1

36.2

38.3

45.8

27.5

16.0

8.0

-

yellow pond-lily

Nuphar variegata

-

-

4.3

2.1

-

-

-

-

-

white water-lily

Nymphaea odorata

46.8

39.1

31.9

36.2

45.8

27.5

16.0

8.0

-

Total number of species recorded

4

6

7

7

6

6

5

5

4