Yellow perch spawning assessment, Green Can Reef – 2004
In 2004, our annual yellow perch spawning assessment began on 5/26/2004. The temperature profile indicated that the bottom temperature was at 49 0F and the surface temperature was at 53 0F. We sampled at three different depths on 5/26 – shallow (30-33’), middle (38-47’) and deep (50-55’). At each depth, one box of 300 ft net with three mesh sizes (2”, 2.5” and 2.75”, 100 ft each) was fished for one night. Yellow perch were captured at all three depths. A total of 725 yellow perch were caught. Greater proportion of females was captured in the deep set. Overall, very few females were ripe/spent at this time. A second sample was taken on 6/2/2004 which had no spent female. The bottom temperature was 47 0F. Overall, the effort was kept at a modest level so as to minimize the negative impact. The third lift was taken on 6/9/2004 with one gang of 600 ft set at 35-38’. Only 17 yellow perch were caught of which six of seven females were spent indicating peak egg deposition.
Bottom temp: 47 to 49 F.
|
Sampling date |
Number (all) |
Number (male) |
Number (female) |
|
May 26th |
805 |
688 | 118 |
|
June 2nd |
665 |
409 | 52 |
|
June 9th |
28 |
17 | 12 |
111 perch were aged; 86% belonged to 1988 year-class.
Age distribution during spawning assessment: 111 perch were aged using anal spine. The following table indicates the year-class representation in the spawning population. 86% of yellow perch belonged to the 1998 year-class.
| Age | # perch | Year-class |
| 3 | 4 | 2001 |
| 4 | 1 | 2000 |
| 5 | 3 | 1999 |
| 6 | 96 | 1998 |
| 7 | 3 | 1997 |
| 8 | 1 | 1996 |
| 11 | 1 | 1993 |
| 13 | 2 | 1991 |
2004 – yellow perch egg deposition survey:
The WDNR dive team continued the effort using the protocol similar to 2003 to quantify egg deposition in the Green Can Reef area.
|
2004 Diving for yellow perch egg deposition |
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|
Date |
Divers |
Depth |
Location |
Area searched |
# of egg masses |
|
June 14 |
Paul Peeters |
35-42 |
West of Green Can |
12 |
0 |
|
Brad Eggold |
12 |
0 |
|||
|
June 14 |
Tim Kroeff |
35 – 45 |
South and West of Green Can |
15 |
0 |
|
Cheryl Peterson |
15 |
0 |
|||
|
June 14 |
Paul Peeters |
48 – 50 |
East of Green Can |
20 |
0 |
|
Brad Eggold |
20 |
0 |
|||
|
June 14 |
Tim Kroeff |
35 - 42 |
East looping around Green Can |
12 |
1 |
|
Cheryl Peterson |
12 |
0 |
|||
|
June 14 |
Paul Peeters |
55 - 65 |
Northeast of Green Can |
20 |
0 |
|
Brad Eggold |
20 |
0 |
|||
|
June 21 |
Paul Peeters |
32 - 42 |
West and South of Green Can |
20 |
0 |
|
Brad Eggold |
20 |
0 |
|||
|
June 21 |
Tim Kroeff |
55 – 65 |
Southeast of Green Can |
20 |
0 |
|
Paul Peeters |
20 |
0 |
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Total Area searched = 21,760 m2
Total eggs found = 1
Egg masses per 1000 m2 = 0.046