. The Canadian field-naturalist. BROOK TROUT (517). PUMPKINSEED (5641) (1153) FORK LENGTH (cm) Figure 2. Length distribution (solid lines) of Brook Trout, Brown Bullheads, and Pumpkinseeds collected following the reclamation of Redpine Lake. Broken lines represent fish marked and released before poisoning. Numbers offish mea- sured are in parentheses. In all instances, the estimates based on underwater transects were significantly lower than the Petersen estimates. A probable explanation is that some dying fish entered the soft organic substrate and died there, out of sight. Estimates based on
. The Canadian field-naturalist. BROOK TROUT (517). PUMPKINSEED (5641) (1153) FORK LENGTH (cm) Figure 2. Length distribution (solid lines) of Brook Trout, Brown Bullheads, and Pumpkinseeds collected following the reclamation of Redpine Lake. Broken lines represent fish marked and released before poisoning. Numbers offish mea- sured are in parentheses. In all instances, the estimates based on underwater transects were significantly lower than the Petersen estimates. A probable explanation is that some dying fish entered the soft organic substrate and died there, out of sight. Estimates based only on fish seen and collected from the lake bottom would, therefore, be biased on the low side. Divers observed fish with only tails protruding from the lake bottom and suggested that there were probably others completely hidden in the organic ooze. Rupp and DeRoche (1965) reported that dying bullheads apparently had burrowed into the bottom siltduring rotenone treatment of Shagg Lake, Maine. Divers in our study reported seeing Brook Trout and suckers, as well as bullheads, with only their tails protruding from the lake bottom. Discussion The procedure of marking and releasing fish before lake poisoning, as recommended by Carlander and Lewis (1948), provides for an estimate of percentage recovery in the collection offish. Appleget( 1949) used. 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 Ottawa Field-Naturalists' Club. Ottawa, Ottawa Field-Naturalists' Club
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