Upper Midwest Environmental Sciences Center

UMESC - LTRMP Reports - Macroinvertebrate - Table 3. Estimated mean numbers of mayflies, fingernail clams, midges, Asiatic clams, and zebra mussels per square meter by year and study area, weighted by areas of strata
Macroinvertebrate Update Title Page
 Tables


Table 2.

Estimated mean numbers of mayflies, fingernail clams, midges, Asiatic clams, and zebra mussels per square meter by year and study area, weighted by areas of strata. For sample sizes, refer to Table 1. Midges were added to the sampling design in 1993 and zebra mussels in 1995. The wash frame sieve size was changed from a U.S. Standard Sieve no. 30 (0.595 µm), used in 1992, to a U.S. Standard Sieve no. 16 (1.18 mm) in 1993. SE=standard error.

Study reach
Year
Mayflies
(m-2)
±
1 SE
Fingernail
clams
(m-2)
±
1 SE
Midges (m-2)
±
1 SE
Corbicula
sp. (m-2)
±
1 SE
Zebra mussels
(m-2)
±
1 SE
Pool 4
1992
59
18
47
19
—
—
0
0
—
—
 
1993
128
36
74
11
318
39
0
0
—
—
 
1994
203
50
88
12
185
32
0
0
—
—
 
1995
171
34
59
13
78
13
0
0
26
26
 
1996
132
34
39
7
38
12
0
0
116
113
 
1997
69
21
76
9
152
35
0
0
31
27
 
1998
209
44
73
10
253
40
0
0
107
98
 
1999
69
18
138
21
199
33
0
0
37
33
 
2000
223
39
118
14
65
15
0
0
31
29
  2001
104
19
103
14
71
13
0
0
232
218
  2002
93
31
79
10
68
16
0
0
8
6
  2003a
—
—
—
—
—
—
—
—
—
—
 
2004
84
24
78
13
103
20
0
0
3
2
aSampling not conducted in 2003 because of budget constraints.

 

Study reach
Year
Mayflies
(m-2)
±
1 SE
Fingernail
clams
(m-2)
±
1 SE
Midges (m-2)
±
1 SE
Corbicula
sp. (m-2)
±
1 SE
Zebra mussels
(m-2)
±
1 SE
Pool 8
1992
51
25
15
11
—
—
0
0
—
—
 
1993
118
41
22
11
50
9
0
0
—
—
 
1994
91
31
11
5
27
16
0
0
—
—
 
1995
56
14
6
3
11
4
0
0
0
0
 
1996
38
11
2
1
15
4
0
0
1
0
 
1997
71
16
9
4
26
6
0
0
25
11
 
1998
120
36
26
8
82
18
0
0
26
17
 
1999
215
58
505
158
45
15
0
0
292
132
 
2000
262
70
270
55
38
12
0
0
609
349
  2001
104
30
170
39
38
10
0
0
882
563
  2002
75
25
236
39
62
17
0
0
196
113
  2003
71
22
233
48
30
10
1
1
6
2
  2004
105
27
665
95
349
86
4
4
9
5

 

Study reach
Year
Mayflies
(m-2)
±
1 SE
Fingernail
clams
(m-2)
±
1 SE
Midges (m-2)
±
1 SE
Corbicula
sp. (m-2)
±
1 SE
Zebra mussels
(m-2)
±
1 SE
Pool 13
1992
120
31
84
28
—
—
0
0
—
—
 
1993
155
39
2596
494
509
95
0
0
—
—
 
1994
194
36
594
157
75
34
0
0
—
—
 
1995
187
53
277
88
39
9
0
0
11
7
 
1996
147
38
231
58
21
7
0
0
14
8
 
1997
165
43
87
23
79
36
0
0
562
448
 
1998
167
45
150
33
79
27
0
0
120
93
 
1999
187
46
145
33
234
75
0
0
529
321
 
2000
157
51
126
37
574
88
0
0
172
130
  2001
77
19
333
121
28
14
0
0
428
169
  2002
221
54
366
86
191
47
0
0
448
200
  2003
77
25
243
55
138
27
<1
<1
2
2
  2004
134
44
262
70
264
73
0
0
1131
394

 

Study reach
Year
Mayflies
(m-2)
±
1 SE
Fingernail
clams
(m-2)
±
1 SE
Midges (m-2)
±
1 SE
Corbicula
sp. (m-2)
±
1 SE
Zebra mussels
(m-2)
±
1 SE
Pool 26
1992
21
9
15
9
—
—
2
1
—
—
 
1993
7
2
1
1
10
2
0
0
—
—
 
1994
21
6
5
3
14
8
1
1
—
—
  1995a
—
—
—
—
—
—
—
—
—
—
 
1996
13
10
0
0
18
9
0
0
0
0
 
1997
16
8
1
1
13
6
0
0
1
1
 
1998
25
16
4
4
5
2
4
3
29
24
 
1999
28
15
1
1
9
4
1
1
2
2
 
2000
27
11
0
0
27
8
2
2
109
105
 
2001
7
3
1
1
30
8
<1
<1
7
6
 
2002
44
22
1
<1
52
14
<1
<1
0
0
  2003b
—
—
—
—
—
—
—
—
—
—
 
2004
3
1
3
2
35
12
0
0
1
1
aSampling not completed because of high water.
bSampling not conducted in 2003 because of budget constraints.

 

Study reach
Year
Mayflies
(m-2)
±
1 SE
Fingernail
clams
(m-2)
±
1 SE
Midges (m-2)
±
1 SE
Corbicula
sp. (m-2)
±
1 SE
Zebra mussels
(m-2)
±
1 SE
Open River Reach
1992
22
12
5
3
—
—
1
1
—
—
 
1993a
                    
 
1994
19
9
1
1
8
4
2
1
—
—
 
1995
12
6
0
0
14
5
2
1
2
2
 
1996
11
6
0
0
5
2
1
1
0
0
 
1997a
                    
 
1998
12
9
0
0
4
2
1
1
20
17
 
1999
3
2
0
0
6
3
1
1
100
74
 
2000
9
5
0
0
22
7
0
0
71
64
 
2001b
—
—
—
—
—
—
—
—
—
—
aSampling not conducted in 1993 or 1997 because of high water.
bSampling discontinued in 2001.

 

Study reach
Year
Mayflies
(m-2)
±
1 SE
Fingernail
clams
(m-2)
±
1 SE
Midges (m-2)
±
1 SE
Corbicula
sp. (m-2)
±
1 SE
Zebra mussels
(m-2)
±
1 SE
La Grange Pool
1992
13
6
4
2
—
—
0
0
—
—
 
1993
11
5
17
10
52
14
0
0
—
—
 
1994
27
8
51
13
57
10
10
3
—
—
 
1995
6
4
17
9
29
11
2
1
11
11
 
1996
4
1
5
3
150
50
1
1
0
0
 
1997
8
3
9
5
101
33
0
0
0
0
 
1998
9
6
21
12
91
25
1
1
3
1
 
1999
9
5
13
5
46
16
0
0
0
0
 
2000
7
5
10
8
67
22
0
0
1
1
  2001
3
1
9
4
51
13
0
0
<1
<1
  2002
4
2
33
14
98
20
0
0
0
0
 
2003a
—
—
—
—
—
—
—
—
—
—
 
2004
8
4
8
4
75
19
0
0
0
0
aSampling not conducted in 2003 because of budget constraints.

Content manager: Jennie Sauer

July 18, 2006
Page Last Modified: April 17, 2018