A.  Percent frequencies calculated using all areas of Goose Island.

Year

1992

1993

1994

1995

1996

1997

1998

1999

2000

Number of sites sampled

113

114

112

113

114

114

115

109

111

All submersed vegetation

53.1

50.0

52.7

61.9

69.3

96.5

100

100

99.0

coontail

5.3

35.1

30.4

34.5

54.4

86.0

98.3

99.1

98.2

chara

Chara spp.

-

-

-

-

-

-

-

0.9

-

Canadian waterweed

Elodea canadensis

-

4.4

1.8

0.9

3.5

56.1

75.7

94.5

95.5

water stargrass

Heteranthera dubia

-

-

-

0.9

-

-

4.3

0.9

0.9

Eurasian watermilfoil

Myriophyllum spicatum

38.9

19.3

27.7

29.2

33.3

93.9

20.0

16.5

33.3

nodding waternymph

Najas flexilis

0.9

-

1.8

1.8

-

1.8

1.7

1.8

-

curly pondweed

Potamogeton crispus

9.7

-

17.0

3.5

0.9

18.4

13.9

8.2

16.2

leafy/small pondweed

P. foliosus/P. pusillus

-

-

3.6

4.4

9.6

14.0

13.9

6.4

13.5

longleaf pondweed

P. nodosus

1.8

4.4

3.6

6.2

5.3

1.8

0.9

2.8

0.9

sago pondweed

P. pectinatus

12.4

-

9.8

9.7

6.1

1.8

6.1

1.8

-

flatstem pondweed

P. zosteriformis

-

0.9

5.4

3.5

16.7

40.4

64.3

76.1

73.9

All rooted floating leaf vegetation

47.8

39.5

38.4

51.3

70.2

58.8

53.9

52.3

50.4

American lotus

Nelumbo lutea

13.3

9.6

4.5

21.2

31.6

21.9

13.9

12.8

9.0

yellow pond-lily

Nuphar variegata

-

-

-

-

-

1.8

-

-

-

white water-lily

Nymphaea odorata

38.9

30.7

36.6

37.2

47.4

42.1

42.6

44.0

44.1

Total number of species recorded

8

7

11

12

10

12

12

13

10

Percent frequencies calculated using only areas of Goose Island sampled during the 2001 drawdown.

Year

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

Number of sites sampled

90

90

90

90

90

91

91

87

88

78

All submersed vegetation

58.9

53.3

53.3

61.1

71.1

98.9

100

100

98.9

93.4

coontail

6.7

38.9

32.2

35.6

57.8

85.7

98.9

98.9

97.7

84.6

chara

Chara spp.

-

-

-

-

-

-

-

1.1

-

5.1

Canadian waterweed

Elodea canadensis

-

4.4

2.2

-

3.3

58.2

81.3

95.4

94.3

70.5

water stargrass

Heteranthera dubia

-

-

-

1.1

-

-

3.3

1.1

1.1

6.4

Eurasian watermilfoil

Myriophyllum spicatum

42.2

18.9

27.8

23.3

30.0

98.9

23.1

16.1

35.2

6.4

nodding waternymph

Najas flexilis

1.1

-

2.2

2.2

-

2.2

1.1

1.1

-

1.3

curly pondweed

Potamogeton crispus

11.1

-

17.8

3.3

1.1

20.9

16.5

6.9

14.8

33.3

leafy/small pondweed

P. foliosus/P. pusillus

-

-

4.4

3.3

11.1

14.3

14.3

6.9

14.8

10.3

longleaf pondweed

P. nodosus

1.1

5.6

2.2

5.6

4.4

2.2

2.2

3.4

1.1

1.3

sago pondweed

P. pectinatus

13.3

-

11.1

12.2

7.8

2.2

7.7

2.3

-

5.1

flatstem pondweed

P. zosteriformis

-

1.1

3.3

4.4

16.7

38.5

65.9

71.3

72.7

66.7

All rooted floating leaf vegetation

52.2

41.1

41.1

47.8

64.4

58.2

51.6

57.5

55.7

57.7

American lotus

Nelumbo lutea

15.5

10.0

3.3

15.6

22.2

15.4

6.6

11.5

6.8

6.4

yellow pond-lily

Nuphar variegata

-

-

-

-

-

2.2

-

-

-

-

white water-lily

Nymphaea odorata

41.1

32.2

40.0

40.0

51.1

48.4

47.3

50.6

52.3

56.4

Total number of species recorded

8

7

11

11

10

12

12

13

10

13