. The Canadian field-naturalist. 160 The Canadian Field-Naturalist Vol. 83 Vertical Distribution of A^^hite Perch, Roccus america?ms, modified by Light During the summer of 1967, an attempt was made to record the diel vertical distribution of white perch in the Bav of Quinte, Lake Ontario. A bottom trawl operated both during the dav and night, proved unsuitable. A speciallv constructed 18 foot deep gill net with panels of ; 2; and 3 inch mesh dis- tributed at all depths was impractical because few white perch were taken and the net was choked with alewives {Fomolabiis psetidoharengiis).
. The Canadian field-naturalist. 160 The Canadian Field-Naturalist Vol. 83 Vertical Distribution of A^^hite Perch, Roccus america?ms, modified by Light During the summer of 1967, an attempt was made to record the diel vertical distribution of white perch in the Bav of Quinte, Lake Ontario. A bottom trawl operated both during the dav and night, proved unsuitable. A speciallv constructed 18 foot deep gill net with panels of ; 2; and 3 inch mesh dis- tributed at all depths was impractical because few white perch were taken and the net was choked with alewives {Fomolabiis psetidoharengiis). Winder- mere traps operated off the dock of the Fisheries Station at Glenora gave the best information. Previous experience had indicated that white perch were abundant here during the month of July. Each trap was 4' long and 2' in diameter. On one side, there was an opening tapering to 4" and on the other a door for removal of fish. The traps were made of 2" wire gauze or nylon. DEPTH (FEET) Figure 1. The number of white perch taken at the depths indicated per 100 hours night fishing per Windermere trap under normal conditions and with surface illumination. Table 1.âNumbers of white perch caught at various depths in Windermere traps during July in the Bay of Quinte, Lake Ontario (catch per unit effort in parenthesis) Number of fish and CUE at each depth Hours (depths in feet) Type of Lift No. fishing 4 8 12 16 20 Day 10 86 1 3 - () - () - Night 15 248 159 181 82 35 48 () () () () () 24-hour 10 240 52 88 ..â ).5 27 40 () () () () () Total of dav, 35 574 211 272 115 63 88 night and 24-hour () () () () () Night, surface 8 112 23 30 37 64 157 iUumination () () () () (). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original wo
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